diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile index e0c7e1e0590b..f4482f9b221f 100644 --- a/Documentation/DocBook/Makefile +++ b/Documentation/DocBook/Makefile @@ -14,7 +14,7 @@ DOCBOOKS := z8530book.xml device-drivers.xml \ genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml \ 80211.xml debugobjects.xml sh.xml regulator.xml \ alsa-driver-api.xml writing-an-alsa-driver.xml \ - tracepoint.xml gpu.xml media_api.xml w1.xml \ + tracepoint.xml media_api.xml w1.xml \ writing_musb_glue_layer.xml crypto-API.xml iio.xml include Documentation/DocBook/media/Makefile diff --git a/Documentation/DocBook/gpu.tmpl b/Documentation/DocBook/gpu.tmpl deleted file mode 100644 index d09536c91717..000000000000 --- a/Documentation/DocBook/gpu.tmpl +++ /dev/null @@ -1,3528 +0,0 @@ - - - - - - Linux GPU Driver Developer's Guide - - - - Jesse - Barnes - Initial version - - Intel Corporation -
- jesse.barnes@intel.com -
- - - - Laurent - Pinchart - Driver internals - - Ideas on board SPRL -
- laurent.pinchart@ideasonboard.com -
- - - - Daniel - Vetter - Contributions all over the place - - Intel Corporation -
- daniel.vetter@ffwll.ch -
- - - - Lukas - Wunner - vga_switcheroo documentation - -
- lukas@wunner.de -
- - - - - - 2008-2009 - 2013-2014 - Intel Corporation - - - 2012 - Laurent Pinchart - - - 2015 - Lukas Wunner - - - - - The contents of this file may be used under the terms of the GNU - General Public License version 2 (the "GPL") as distributed in - the kernel source COPYING file. - - - - - - - 1.0 - 2012-07-13 - LP - Added extensive documentation about driver internals. - - - - 1.1 - 2015-10-11 - LW - Added vga_switcheroo documentation. - - - - - - - - - DRM Core - - - This first part of the GPU Driver Developer's Guide documents core DRM - code, helper libraries for writing drivers and generic userspace - interfaces exposed by DRM drivers. - - - - - Introduction - - The Linux DRM layer contains code intended to support the needs - of complex graphics devices, usually containing programmable - pipelines well suited to 3D graphics acceleration. Graphics - drivers in the kernel may make use of DRM functions to make - tasks like memory management, interrupt handling and DMA easier, - and provide a uniform interface to applications. - - - A note on versions: this guide covers features found in the DRM - tree, including the TTM memory manager, output configuration and - mode setting, and the new vblank internals, in addition to all - the regular features found in current kernels. - - - [Insert diagram of typical DRM stack here] - - - Style Guidelines - - For consistency this documentation uses American English. Abbreviations - are written as all-uppercase, for example: DRM, KMS, IOCTL, CRTC, and so - on. To aid in reading, documentations make full use of the markup - characters kerneldoc provides: @parameter for function parameters, @member - for structure members, &structure to reference structures and - function() for functions. These all get automatically hyperlinked if - kerneldoc for the referenced objects exists. When referencing entries in - function vtables please use ->vfunc(). Note that kerneldoc does - not support referencing struct members directly, so please add a reference - to the vtable struct somewhere in the same paragraph or at least section. - - - Except in special situations (to separate locked from unlocked variants) - locking requirements for functions aren't documented in the kerneldoc. - Instead locking should be check at runtime using e.g. - WARN_ON(!mutex_is_locked(...));. Since it's much easier to - ignore documentation than runtime noise this provides more value. And on - top of that runtime checks do need to be updated when the locking rules - change, increasing the chances that they're correct. Within the - documentation the locking rules should be explained in the relevant - structures: Either in the comment for the lock explaining what it - protects, or data fields need a note about which lock protects them, or - both. - - - Functions which have a non-void return value should have a - section called "Returns" explaining the expected return values in - different cases and their meanings. Currently there's no consensus whether - that section name should be all upper-case or not, and whether it should - end in a colon or not. Go with the file-local style. Other common section - names are "Notes" with information for dangerous or tricky corner cases, - and "FIXME" where the interface could be cleaned up. - - - - - - - - DRM Internals - - This chapter documents DRM internals relevant to driver authors - and developers working to add support for the latest features to - existing drivers. - - - First, we go over some typical driver initialization - requirements, like setting up command buffers, creating an - initial output configuration, and initializing core services. - Subsequent sections cover core internals in more detail, - providing implementation notes and examples. - - - The DRM layer provides several services to graphics drivers, - many of them driven by the application interfaces it provides - through libdrm, the library that wraps most of the DRM ioctls. - These include vblank event handling, memory - management, output management, framebuffer management, command - submission & fencing, suspend/resume support, and DMA - services. - - - - - - Driver Initialization - - At the core of every DRM driver is a drm_driver - structure. Drivers typically statically initialize a drm_driver structure, - and then pass it to drm_dev_alloc() to allocate a - device instance. After the device instance is fully initialized it can be - registered (which makes it accessible from userspace) using - drm_dev_register(). - - - The drm_driver structure contains static - information that describes the driver and features it supports, and - pointers to methods that the DRM core will call to implement the DRM API. - We will first go through the drm_driver static - information fields, and will then describe individual operations in - details as they get used in later sections. - - - Driver Information - - Driver Features - - Drivers inform the DRM core about their requirements and supported - features by setting appropriate flags in the - driver_features field. Since those flags - influence the DRM core behaviour since registration time, most of them - must be set to registering the drm_driver - instance. - - u32 driver_features; - - Driver Feature Flags - - DRIVER_USE_AGP - - Driver uses AGP interface, the DRM core will manage AGP resources. - - - - DRIVER_REQUIRE_AGP - - Driver needs AGP interface to function. AGP initialization failure - will become a fatal error. - - - - DRIVER_PCI_DMA - - Driver is capable of PCI DMA, mapping of PCI DMA buffers to - userspace will be enabled. Deprecated. - - - - DRIVER_SG - - Driver can perform scatter/gather DMA, allocation and mapping of - scatter/gather buffers will be enabled. Deprecated. - - - - DRIVER_HAVE_DMA - - Driver supports DMA, the userspace DMA API will be supported. - Deprecated. - - - - DRIVER_HAVE_IRQDRIVER_IRQ_SHARED - - DRIVER_HAVE_IRQ indicates whether the driver has an IRQ handler - managed by the DRM Core. The core will support simple IRQ handler - installation when the flag is set. The installation process is - described in . - DRIVER_IRQ_SHARED indicates whether the device & handler - support shared IRQs (note that this is required of PCI drivers). - - - - DRIVER_GEM - - Driver use the GEM memory manager. - - - - DRIVER_MODESET - - Driver supports mode setting interfaces (KMS). - - - - DRIVER_PRIME - - Driver implements DRM PRIME buffer sharing. - - - - DRIVER_RENDER - - Driver supports dedicated render nodes. - - - - DRIVER_ATOMIC - - Driver supports atomic properties. In this case the driver - must implement appropriate obj->atomic_get_property() vfuncs - for any modeset objects with driver specific properties. - - - - - - Major, Minor and Patchlevel - int major; -int minor; -int patchlevel; - - The DRM core identifies driver versions by a major, minor and patch - level triplet. The information is printed to the kernel log at - initialization time and passed to userspace through the - DRM_IOCTL_VERSION ioctl. - - - The major and minor numbers are also used to verify the requested driver - API version passed to DRM_IOCTL_SET_VERSION. When the driver API changes - between minor versions, applications can call DRM_IOCTL_SET_VERSION to - select a specific version of the API. If the requested major isn't equal - to the driver major, or the requested minor is larger than the driver - minor, the DRM_IOCTL_SET_VERSION call will return an error. Otherwise - the driver's set_version() method will be called with the requested - version. - - - - Name, Description and Date - char *name; -char *desc; -char *date; - - The driver name is printed to the kernel log at initialization time, - used for IRQ registration and passed to userspace through - DRM_IOCTL_VERSION. - - - The driver description is a purely informative string passed to - userspace through the DRM_IOCTL_VERSION ioctl and otherwise unused by - the kernel. - - - The driver date, formatted as YYYYMMDD, is meant to identify the date of - the latest modification to the driver. However, as most drivers fail to - update it, its value is mostly useless. The DRM core prints it to the - kernel log at initialization time and passes it to userspace through the - DRM_IOCTL_VERSION ioctl. - - - - - Device Instance and Driver Handling -!Pdrivers/gpu/drm/drm_drv.c driver instance overview -!Edrivers/gpu/drm/drm_drv.c - - - Driver Load - - IRQ Registration - - The DRM core tries to facilitate IRQ handler registration and - unregistration by providing drm_irq_install and - drm_irq_uninstall functions. Those functions only - support a single interrupt per device, devices that use more than one - IRQs need to be handled manually. - - - Managed IRQ Registration - - drm_irq_install starts by calling the - irq_preinstall driver operation. The operation - is optional and must make sure that the interrupt will not get fired by - clearing all pending interrupt flags or disabling the interrupt. - - - The passed-in IRQ will then be requested by a call to - request_irq. If the DRIVER_IRQ_SHARED driver - feature flag is set, a shared (IRQF_SHARED) IRQ handler will be - requested. - - - The IRQ handler function must be provided as the mandatory irq_handler - driver operation. It will get passed directly to - request_irq and thus has the same prototype as all - IRQ handlers. It will get called with a pointer to the DRM device as the - second argument. - - - Finally the function calls the optional - irq_postinstall driver operation. The operation - usually enables interrupts (excluding the vblank interrupt, which is - enabled separately), but drivers may choose to enable/disable interrupts - at a different time. - - - drm_irq_uninstall is similarly used to uninstall an - IRQ handler. It starts by waking up all processes waiting on a vblank - interrupt to make sure they don't hang, and then calls the optional - irq_uninstall driver operation. The operation - must disable all hardware interrupts. Finally the function frees the IRQ - by calling free_irq. - - - - Manual IRQ Registration - - Drivers that require multiple interrupt handlers can't use the managed - IRQ registration functions. In that case IRQs must be registered and - unregistered manually (usually with the request_irq - and free_irq functions, or their devm_* equivalent). - - - When manually registering IRQs, drivers must not set the DRIVER_HAVE_IRQ - driver feature flag, and must not provide the - irq_handler driver operation. They must set the - drm_device irq_enabled - field to 1 upon registration of the IRQs, and clear it to 0 after - unregistering the IRQs. - - - - - Memory Manager Initialization - - Every DRM driver requires a memory manager which must be initialized at - load time. DRM currently contains two memory managers, the Translation - Table Manager (TTM) and the Graphics Execution Manager (GEM). - This document describes the use of the GEM memory manager only. See - for details. - - - - Miscellaneous Device Configuration - - Another task that may be necessary for PCI devices during configuration - is mapping the video BIOS. On many devices, the VBIOS describes device - configuration, LCD panel timings (if any), and contains flags indicating - device state. Mapping the BIOS can be done using the pci_map_rom() call, - a convenience function that takes care of mapping the actual ROM, - whether it has been shadowed into memory (typically at address 0xc0000) - or exists on the PCI device in the ROM BAR. Note that after the ROM has - been mapped and any necessary information has been extracted, it should - be unmapped; on many devices, the ROM address decoder is shared with - other BARs, so leaving it mapped could cause undesired behaviour like - hangs or memory corruption. - - - - - - Bus-specific Device Registration and PCI Support - - A number of functions are provided to help with device registration. - The functions deal with PCI and platform devices respectively and are - only provided for historical reasons. These are all deprecated and - shouldn't be used in new drivers. Besides that there's a few - helpers for pci drivers. - -!Edrivers/gpu/drm/drm_pci.c -!Edrivers/gpu/drm/drm_platform.c - - - - - - - Memory management - - Modern Linux systems require large amount of graphics memory to store - frame buffers, textures, vertices and other graphics-related data. Given - the very dynamic nature of many of that data, managing graphics memory - efficiently is thus crucial for the graphics stack and plays a central - role in the DRM infrastructure. - - - The DRM core includes two memory managers, namely Translation Table Maps - (TTM) and Graphics Execution Manager (GEM). TTM was the first DRM memory - manager to be developed and tried to be a one-size-fits-them all - solution. It provides a single userspace API to accommodate the need of - all hardware, supporting both Unified Memory Architecture (UMA) devices - and devices with dedicated video RAM (i.e. most discrete video cards). - This resulted in a large, complex piece of code that turned out to be - hard to use for driver development. - - - GEM started as an Intel-sponsored project in reaction to TTM's - complexity. Its design philosophy is completely different: instead of - providing a solution to every graphics memory-related problems, GEM - identified common code between drivers and created a support library to - share it. GEM has simpler initialization and execution requirements than - TTM, but has no video RAM management capabilities and is thus limited to - UMA devices. - - - The Translation Table Manager (TTM) - - TTM design background and information belongs here. - - - TTM initialization - This section is outdated. - - Drivers wishing to support TTM must fill out a drm_bo_driver - structure. The structure contains several fields with function - pointers for initializing the TTM, allocating and freeing memory, - waiting for command completion and fence synchronization, and memory - migration. See the radeon_ttm.c file for an example of usage. - - - The ttm_global_reference structure is made up of several fields: - - - struct ttm_global_reference { - enum ttm_global_types global_type; - size_t size; - void *object; - int (*init) (struct ttm_global_reference *); - void (*release) (struct ttm_global_reference *); - }; - - - There should be one global reference structure for your memory - manager as a whole, and there will be others for each object - created by the memory manager at runtime. Your global TTM should - have a type of TTM_GLOBAL_TTM_MEM. The size field for the global - object should be sizeof(struct ttm_mem_global), and the init and - release hooks should point at your driver-specific init and - release routines, which probably eventually call - ttm_mem_global_init and ttm_mem_global_release, respectively. - - - Once your global TTM accounting structure is set up and initialized - by calling ttm_global_item_ref() on it, - you need to create a buffer object TTM to - provide a pool for buffer object allocation by clients and the - kernel itself. The type of this object should be TTM_GLOBAL_TTM_BO, - and its size should be sizeof(struct ttm_bo_global). Again, - driver-specific init and release functions may be provided, - likely eventually calling ttm_bo_global_init() and - ttm_bo_global_release(), respectively. Also, like the previous - object, ttm_global_item_ref() is used to create an initial reference - count for the TTM, which will call your initialization function. - - - - - The Graphics Execution Manager (GEM) - - The GEM design approach has resulted in a memory manager that doesn't - provide full coverage of all (or even all common) use cases in its - userspace or kernel API. GEM exposes a set of standard memory-related - operations to userspace and a set of helper functions to drivers, and let - drivers implement hardware-specific operations with their own private API. - - - The GEM userspace API is described in the - GEM - the Graphics - Execution Manager article on LWN. While slightly - outdated, the document provides a good overview of the GEM API principles. - Buffer allocation and read and write operations, described as part of the - common GEM API, are currently implemented using driver-specific ioctls. - - - GEM is data-agnostic. It manages abstract buffer objects without knowing - what individual buffers contain. APIs that require knowledge of buffer - contents or purpose, such as buffer allocation or synchronization - primitives, are thus outside of the scope of GEM and must be implemented - using driver-specific ioctls. - - - On a fundamental level, GEM involves several operations: - - Memory allocation and freeing - Command execution - Aperture management at command execution time - - Buffer object allocation is relatively straightforward and largely - provided by Linux's shmem layer, which provides memory to back each - object. - - - Device-specific operations, such as command execution, pinning, buffer - read & write, mapping, and domain ownership transfers are left to - driver-specific ioctls. - - - GEM Initialization - - Drivers that use GEM must set the DRIVER_GEM bit in the struct - drm_driver - driver_features field. The DRM core will - then automatically initialize the GEM core before calling the - load operation. Behind the scene, this will - create a DRM Memory Manager object which provides an address space - pool for object allocation. - - - In a KMS configuration, drivers need to allocate and initialize a - command ring buffer following core GEM initialization if required by - the hardware. UMA devices usually have what is called a "stolen" - memory region, which provides space for the initial framebuffer and - large, contiguous memory regions required by the device. This space is - typically not managed by GEM, and must be initialized separately into - its own DRM MM object. - - - - GEM Objects Creation - - GEM splits creation of GEM objects and allocation of the memory that - backs them in two distinct operations. - - - GEM objects are represented by an instance of struct - drm_gem_object. Drivers usually need to extend - GEM objects with private information and thus create a driver-specific - GEM object structure type that embeds an instance of struct - drm_gem_object. - - - To create a GEM object, a driver allocates memory for an instance of its - specific GEM object type and initializes the embedded struct - drm_gem_object with a call to - drm_gem_object_init. The function takes a pointer to - the DRM device, a pointer to the GEM object and the buffer object size - in bytes. - - - GEM uses shmem to allocate anonymous pageable memory. - drm_gem_object_init will create an shmfs file of - the requested size and store it into the struct - drm_gem_object filp - field. The memory is used as either main storage for the object when the - graphics hardware uses system memory directly or as a backing store - otherwise. - - - Drivers are responsible for the actual physical pages allocation by - calling shmem_read_mapping_page_gfp for each page. - Note that they can decide to allocate pages when initializing the GEM - object, or to delay allocation until the memory is needed (for instance - when a page fault occurs as a result of a userspace memory access or - when the driver needs to start a DMA transfer involving the memory). - - - Anonymous pageable memory allocation is not always desired, for instance - when the hardware requires physically contiguous system memory as is - often the case in embedded devices. Drivers can create GEM objects with - no shmfs backing (called private GEM objects) by initializing them with - a call to drm_gem_private_object_init instead of - drm_gem_object_init. Storage for private GEM - objects must be managed by drivers. - - - - GEM Objects Lifetime - - All GEM objects are reference-counted by the GEM core. References can be - acquired and release by calling drm_gem_object_reference - and drm_gem_object_unreference respectively. The - caller must hold the drm_device - struct_mutex lock when calling - drm_gem_object_reference. As a convenience, GEM - provides drm_gem_object_unreference_unlocked - functions that can be called without holding the lock. - - - When the last reference to a GEM object is released the GEM core calls - the drm_driver - gem_free_object operation. That operation is - mandatory for GEM-enabled drivers and must free the GEM object and all - associated resources. - - - void (*gem_free_object) (struct drm_gem_object *obj); - Drivers are responsible for freeing all GEM object resources. This includes - the resources created by the GEM core, which need to be released with - drm_gem_object_release. - - - - GEM Objects Naming - - Communication between userspace and the kernel refers to GEM objects - using local handles, global names or, more recently, file descriptors. - All of those are 32-bit integer values; the usual Linux kernel limits - apply to the file descriptors. - - - GEM handles are local to a DRM file. Applications get a handle to a GEM - object through a driver-specific ioctl, and can use that handle to refer - to the GEM object in other standard or driver-specific ioctls. Closing a - DRM file handle frees all its GEM handles and dereferences the - associated GEM objects. - - - To create a handle for a GEM object drivers call - drm_gem_handle_create. The function takes a pointer - to the DRM file and the GEM object and returns a locally unique handle. - When the handle is no longer needed drivers delete it with a call to - drm_gem_handle_delete. Finally the GEM object - associated with a handle can be retrieved by a call to - drm_gem_object_lookup. - - - Handles don't take ownership of GEM objects, they only take a reference - to the object that will be dropped when the handle is destroyed. To - avoid leaking GEM objects, drivers must make sure they drop the - reference(s) they own (such as the initial reference taken at object - creation time) as appropriate, without any special consideration for the - handle. For example, in the particular case of combined GEM object and - handle creation in the implementation of the - dumb_create operation, drivers must drop the - initial reference to the GEM object before returning the handle. - - - GEM names are similar in purpose to handles but are not local to DRM - files. They can be passed between processes to reference a GEM object - globally. Names can't be used directly to refer to objects in the DRM - API, applications must convert handles to names and names to handles - using the DRM_IOCTL_GEM_FLINK and DRM_IOCTL_GEM_OPEN ioctls - respectively. The conversion is handled by the DRM core without any - driver-specific support. - - - GEM also supports buffer sharing with dma-buf file descriptors through - PRIME. GEM-based drivers must use the provided helpers functions to - implement the exporting and importing correctly. See . - Since sharing file descriptors is inherently more secure than the - easily guessable and global GEM names it is the preferred buffer - sharing mechanism. Sharing buffers through GEM names is only supported - for legacy userspace. Furthermore PRIME also allows cross-device - buffer sharing since it is based on dma-bufs. - - - - GEM Objects Mapping - - Because mapping operations are fairly heavyweight GEM favours - read/write-like access to buffers, implemented through driver-specific - ioctls, over mapping buffers to userspace. However, when random access - to the buffer is needed (to perform software rendering for instance), - direct access to the object can be more efficient. - - - The mmap system call can't be used directly to map GEM objects, as they - don't have their own file handle. Two alternative methods currently - co-exist to map GEM objects to userspace. The first method uses a - driver-specific ioctl to perform the mapping operation, calling - do_mmap under the hood. This is often considered - dubious, seems to be discouraged for new GEM-enabled drivers, and will - thus not be described here. - - - The second method uses the mmap system call on the DRM file handle. - void *mmap(void *addr, size_t length, int prot, int flags, int fd, - off_t offset); - DRM identifies the GEM object to be mapped by a fake offset passed - through the mmap offset argument. Prior to being mapped, a GEM object - must thus be associated with a fake offset. To do so, drivers must call - drm_gem_create_mmap_offset on the object. - - - Once allocated, the fake offset value - must be passed to the application in a driver-specific way and can then - be used as the mmap offset argument. - - - The GEM core provides a helper method drm_gem_mmap - to handle object mapping. The method can be set directly as the mmap - file operation handler. It will look up the GEM object based on the - offset value and set the VMA operations to the - drm_driver gem_vm_ops - field. Note that drm_gem_mmap doesn't map memory to - userspace, but relies on the driver-provided fault handler to map pages - individually. - - - To use drm_gem_mmap, drivers must fill the struct - drm_driver gem_vm_ops - field with a pointer to VM operations. - - - struct vm_operations_struct *gem_vm_ops - - struct vm_operations_struct { - void (*open)(struct vm_area_struct * area); - void (*close)(struct vm_area_struct * area); - int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf); - }; - - - The open and close - operations must update the GEM object reference count. Drivers can use - the drm_gem_vm_open and - drm_gem_vm_close helper functions directly as open - and close handlers. - - - The fault operation handler is responsible for mapping individual pages - to userspace when a page fault occurs. Depending on the memory - allocation scheme, drivers can allocate pages at fault time, or can - decide to allocate memory for the GEM object at the time the object is - created. - - - Drivers that want to map the GEM object upfront instead of handling page - faults can implement their own mmap file operation handler. - - - - Memory Coherency - - When mapped to the device or used in a command buffer, backing pages - for an object are flushed to memory and marked write combined so as to - be coherent with the GPU. Likewise, if the CPU accesses an object - after the GPU has finished rendering to the object, then the object - must be made coherent with the CPU's view of memory, usually involving - GPU cache flushing of various kinds. This core CPU<->GPU - coherency management is provided by a device-specific ioctl, which - evaluates an object's current domain and performs any necessary - flushing or synchronization to put the object into the desired - coherency domain (note that the object may be busy, i.e. an active - render target; in that case, setting the domain blocks the client and - waits for rendering to complete before performing any necessary - flushing operations). - - - - Command Execution - - Perhaps the most important GEM function for GPU devices is providing a - command execution interface to clients. Client programs construct - command buffers containing references to previously allocated memory - objects, and then submit them to GEM. At that point, GEM takes care to - bind all the objects into the GTT, execute the buffer, and provide - necessary synchronization between clients accessing the same buffers. - This often involves evicting some objects from the GTT and re-binding - others (a fairly expensive operation), and providing relocation - support which hides fixed GTT offsets from clients. Clients must take - care not to submit command buffers that reference more objects than - can fit in the GTT; otherwise, GEM will reject them and no rendering - will occur. Similarly, if several objects in the buffer require fence - registers to be allocated for correct rendering (e.g. 2D blits on - pre-965 chips), care must be taken not to require more fence registers - than are available to the client. Such resource management should be - abstracted from the client in libdrm. - - - - - GEM Function Reference -!Edrivers/gpu/drm/drm_gem.c -!Iinclude/drm/drm_gem.h - - - VMA Offset Manager -!Pdrivers/gpu/drm/drm_vma_manager.c vma offset manager -!Edrivers/gpu/drm/drm_vma_manager.c -!Iinclude/drm/drm_vma_manager.h - - - PRIME Buffer Sharing - - PRIME is the cross device buffer sharing framework in drm, originally - created for the OPTIMUS range of multi-gpu platforms. To userspace - PRIME buffers are dma-buf based file descriptors. - - - Overview and Driver Interface - - Similar to GEM global names, PRIME file descriptors are - also used to share buffer objects across processes. They offer - additional security: as file descriptors must be explicitly sent over - UNIX domain sockets to be shared between applications, they can't be - guessed like the globally unique GEM names. - - - Drivers that support the PRIME - API must set the DRIVER_PRIME bit in the struct - drm_driver - driver_features field, and implement the - prime_handle_to_fd and - prime_fd_to_handle operations. - - - int (*prime_handle_to_fd)(struct drm_device *dev, - struct drm_file *file_priv, uint32_t handle, - uint32_t flags, int *prime_fd); -int (*prime_fd_to_handle)(struct drm_device *dev, - struct drm_file *file_priv, int prime_fd, - uint32_t *handle); - Those two operations convert a handle to a PRIME file descriptor and - vice versa. Drivers must use the kernel dma-buf buffer sharing framework - to manage the PRIME file descriptors. Similar to the mode setting - API PRIME is agnostic to the underlying buffer object manager, as - long as handles are 32bit unsigned integers. - - - While non-GEM drivers must implement the operations themselves, GEM - drivers must use the drm_gem_prime_handle_to_fd - and drm_gem_prime_fd_to_handle helper functions. - Those helpers rely on the driver - gem_prime_export and - gem_prime_import operations to create a dma-buf - instance from a GEM object (dma-buf exporter role) and to create a GEM - object from a dma-buf instance (dma-buf importer role). - - - struct dma_buf * (*gem_prime_export)(struct drm_device *dev, - struct drm_gem_object *obj, - int flags); -struct drm_gem_object * (*gem_prime_import)(struct drm_device *dev, - struct dma_buf *dma_buf); - These two operations are mandatory for GEM drivers that support - PRIME. - - - - PRIME Helper Functions -!Pdrivers/gpu/drm/drm_prime.c PRIME Helpers - - - - PRIME Function References -!Edrivers/gpu/drm/drm_prime.c - - - DRM MM Range Allocator - - Overview -!Pdrivers/gpu/drm/drm_mm.c Overview - - - LRU Scan/Eviction Support -!Pdrivers/gpu/drm/drm_mm.c lru scan roaster - - - - DRM MM Range Allocator Function References -!Edrivers/gpu/drm/drm_mm.c -!Iinclude/drm/drm_mm.h - - - CMA Helper Functions Reference -!Pdrivers/gpu/drm/drm_gem_cma_helper.c cma helpers -!Edrivers/gpu/drm/drm_gem_cma_helper.c -!Iinclude/drm/drm_gem_cma_helper.h - - - - - - - Mode Setting - - Drivers must initialize the mode setting core by calling - drm_mode_config_init on the DRM device. The function - initializes the drm_device - mode_config field and never fails. Once done, - mode configuration must be setup by initializing the following fields. - - - - int min_width, min_height; -int max_width, max_height; - - Minimum and maximum width and height of the frame buffers in pixel - units. - - - - struct drm_mode_config_funcs *funcs; - Mode setting functions. - - - - Display Modes Function Reference -!Iinclude/drm/drm_modes.h -!Edrivers/gpu/drm/drm_modes.c - - - Atomic Mode Setting Function Reference -!Edrivers/gpu/drm/drm_atomic.c -!Idrivers/gpu/drm/drm_atomic.c - - - Frame Buffer Abstraction - - Frame buffers are abstract memory objects that provide a source of - pixels to scanout to a CRTC. Applications explicitly request the - creation of frame buffers through the DRM_IOCTL_MODE_ADDFB(2) ioctls and - receive an opaque handle that can be passed to the KMS CRTC control, - plane configuration and page flip functions. - - - Frame buffers rely on the underneath memory manager for low-level memory - operations. When creating a frame buffer applications pass a memory - handle (or a list of memory handles for multi-planar formats) through - the drm_mode_fb_cmd2 argument. For drivers using - GEM as their userspace buffer management interface this would be a GEM - handle. Drivers are however free to use their own backing storage object - handles, e.g. vmwgfx directly exposes special TTM handles to userspace - and so expects TTM handles in the create ioctl and not GEM handles. - - - The lifetime of a drm framebuffer is controlled with a reference count, - drivers can grab additional references with - drm_framebuffer_referenceand drop them - again with drm_framebuffer_unreference. For - driver-private framebuffers for which the last reference is never - dropped (e.g. for the fbdev framebuffer when the struct - drm_framebuffer is embedded into the fbdev - helper struct) drivers can manually clean up a framebuffer at module - unload time with - drm_framebuffer_unregister_private. - - - - DRM Format Handling -!Iinclude/drm/drm_fourcc.h -!Edrivers/gpu/drm/drm_fourcc.c - - - Dumb Buffer Objects - - The KMS API doesn't standardize backing storage object creation and - leaves it to driver-specific ioctls. Furthermore actually creating a - buffer object even for GEM-based drivers is done through a - driver-specific ioctl - GEM only has a common userspace interface for - sharing and destroying objects. While not an issue for full-fledged - graphics stacks that include device-specific userspace components (in - libdrm for instance), this limit makes DRM-based early boot graphics - unnecessarily complex. - - - Dumb objects partly alleviate the problem by providing a standard - API to create dumb buffers suitable for scanout, which can then be used - to create KMS frame buffers. - - - To support dumb objects drivers must implement the - dumb_create, - dumb_destroy and - dumb_map_offset operations. - - - - int (*dumb_create)(struct drm_file *file_priv, struct drm_device *dev, - struct drm_mode_create_dumb *args); - - The dumb_create operation creates a driver - object (GEM or TTM handle) suitable for scanout based on the - width, height and depth from the struct - drm_mode_create_dumb argument. It fills the - argument's handle, - pitch and size - fields with a handle for the newly created object and its line - pitch and size in bytes. - - - - int (*dumb_destroy)(struct drm_file *file_priv, struct drm_device *dev, - uint32_t handle); - - The dumb_destroy operation destroys a dumb - object created by dumb_create. - - - - int (*dumb_map_offset)(struct drm_file *file_priv, struct drm_device *dev, - uint32_t handle, uint64_t *offset); - - The dumb_map_offset operation associates an - mmap fake offset with the object given by the handle and returns - it. Drivers must use the - drm_gem_create_mmap_offset function to - associate the fake offset as described in - . - - - - - Note that dumb objects may not be used for gpu acceleration, as has been - attempted on some ARM embedded platforms. Such drivers really must have - a hardware-specific ioctl to allocate suitable buffer objects. - - - - Output Polling - void (*output_poll_changed)(struct drm_device *dev); - - This operation notifies the driver that the status of one or more - connectors has changed. Drivers that use the fb helper can just call the - drm_fb_helper_hotplug_event function to handle this - operation. - - - - - - - - KMS Initialization and Cleanup - - A KMS device is abstracted and exposed as a set of planes, CRTCs, encoders - and connectors. KMS drivers must thus create and initialize all those - objects at load time after initializing mode setting. - - - CRTCs (struct <structname>drm_crtc</structname>) - - A CRTC is an abstraction representing a part of the chip that contains a - pointer to a scanout buffer. Therefore, the number of CRTCs available - determines how many independent scanout buffers can be active at any - given time. The CRTC structure contains several fields to support this: - a pointer to some video memory (abstracted as a frame buffer object), a - display mode, and an (x, y) offset into the video memory to support - panning or configurations where one piece of video memory spans multiple - CRTCs. - - - CRTC Initialization - - A KMS device must create and register at least one struct - drm_crtc instance. The instance is allocated - and zeroed by the driver, possibly as part of a larger structure, and - registered with a call to drm_crtc_init with a - pointer to CRTC functions. - - - - - Planes (struct <structname>drm_plane</structname>) - - A plane represents an image source that can be blended with or overlayed - on top of a CRTC during the scanout process. Planes are associated with - a frame buffer to crop a portion of the image memory (source) and - optionally scale it to a destination size. The result is then blended - with or overlayed on top of a CRTC. - - - The DRM core recognizes three types of planes: - - - DRM_PLANE_TYPE_PRIMARY represents a "main" plane for a CRTC. Primary - planes are the planes operated upon by CRTC modesetting and flipping - operations described in the page_flip hook in drm_crtc_funcs. - - - DRM_PLANE_TYPE_CURSOR represents a "cursor" plane for a CRTC. Cursor - planes are the planes operated upon by the DRM_IOCTL_MODE_CURSOR and - DRM_IOCTL_MODE_CURSOR2 ioctls. - - - DRM_PLANE_TYPE_OVERLAY represents all non-primary, non-cursor planes. - Some drivers refer to these types of planes as "sprites" internally. - - - For compatibility with legacy userspace, only overlay planes are made - available to userspace by default. Userspace clients may set the - DRM_CLIENT_CAP_UNIVERSAL_PLANES client capability bit to indicate that - they wish to receive a universal plane list containing all plane types. - - - Plane Initialization - - To create a plane, a KMS drivers allocates and - zeroes an instances of struct drm_plane - (possibly as part of a larger structure) and registers it with a call - to drm_universal_plane_init. The function takes a bitmask - of the CRTCs that can be associated with the plane, a pointer to the - plane functions, a list of format supported formats, and the type of - plane (primary, cursor, or overlay) being initialized. - - - Cursor and overlay planes are optional. All drivers should provide - one primary plane per CRTC (although this requirement may change in - the future); drivers that do not wish to provide special handling for - primary planes may make use of the helper functions described in - to create and register a - primary plane with standard capabilities. - - - - - Encoders (struct <structname>drm_encoder</structname>) - - An encoder takes pixel data from a CRTC and converts it to a format - suitable for any attached connectors. On some devices, it may be - possible to have a CRTC send data to more than one encoder. In that - case, both encoders would receive data from the same scanout buffer, - resulting in a "cloned" display configuration across the connectors - attached to each encoder. - - - Encoder Initialization - - As for CRTCs, a KMS driver must create, initialize and register at - least one struct drm_encoder instance. The - instance is allocated and zeroed by the driver, possibly as part of a - larger structure. - - - Drivers must initialize the struct drm_encoder - possible_crtcs and - possible_clones fields before registering the - encoder. Both fields are bitmasks of respectively the CRTCs that the - encoder can be connected to, and sibling encoders candidate for cloning. - - - After being initialized, the encoder must be registered with a call to - drm_encoder_init. The function takes a pointer to - the encoder functions and an encoder type. Supported types are - - - DRM_MODE_ENCODER_DAC for VGA and analog on DVI-I/DVI-A - - - DRM_MODE_ENCODER_TMDS for DVI, HDMI and (embedded) DisplayPort - - - DRM_MODE_ENCODER_LVDS for display panels - - - DRM_MODE_ENCODER_TVDAC for TV output (Composite, S-Video, Component, - SCART) - - - DRM_MODE_ENCODER_VIRTUAL for virtual machine displays - - - - - Encoders must be attached to a CRTC to be used. DRM drivers leave - encoders unattached at initialization time. Applications (or the fbdev - compatibility layer when implemented) are responsible for attaching the - encoders they want to use to a CRTC. - - - - - Connectors (struct <structname>drm_connector</structname>) - - A connector is the final destination for pixel data on a device, and - usually connects directly to an external display device like a monitor - or laptop panel. A connector can only be attached to one encoder at a - time. The connector is also the structure where information about the - attached display is kept, so it contains fields for display data, EDID - data, DPMS & connection status, and information about modes - supported on the attached displays. - - - Connector Initialization - - Finally a KMS driver must create, initialize, register and attach at - least one struct drm_connector instance. The - instance is created as other KMS objects and initialized by setting the - following fields. - - - - interlace_allowed - - Whether the connector can handle interlaced modes. - - - - doublescan_allowed - - Whether the connector can handle doublescan. - - - - display_info - - - Display information is filled from EDID information when a display - is detected. For non hot-pluggable displays such as flat panels in - embedded systems, the driver should initialize the - display_info.width_mm - and - display_info.height_mm - fields with the physical size of the display. - - - - polled - - Connector polling mode, a combination of - - - DRM_CONNECTOR_POLL_HPD - - The connector generates hotplug events and doesn't need to be - periodically polled. The CONNECT and DISCONNECT flags must not - be set together with the HPD flag. - - - - DRM_CONNECTOR_POLL_CONNECT - - Periodically poll the connector for connection. - - - - DRM_CONNECTOR_POLL_DISCONNECT - - Periodically poll the connector for disconnection. - - - - Set to 0 for connectors that don't support connection status - discovery. - - - - - The connector is then registered with a call to - drm_connector_init with a pointer to the connector - functions and a connector type, and exposed through sysfs with a call to - drm_connector_register. - - - Supported connector types are - - DRM_MODE_CONNECTOR_VGA - DRM_MODE_CONNECTOR_DVII - DRM_MODE_CONNECTOR_DVID - DRM_MODE_CONNECTOR_DVIA - DRM_MODE_CONNECTOR_Composite - DRM_MODE_CONNECTOR_SVIDEO - DRM_MODE_CONNECTOR_LVDS - DRM_MODE_CONNECTOR_Component - DRM_MODE_CONNECTOR_9PinDIN - DRM_MODE_CONNECTOR_DisplayPort - DRM_MODE_CONNECTOR_HDMIA - DRM_MODE_CONNECTOR_HDMIB - DRM_MODE_CONNECTOR_TV - DRM_MODE_CONNECTOR_eDP - DRM_MODE_CONNECTOR_VIRTUAL - - - - Connectors must be attached to an encoder to be used. For devices that - map connectors to encoders 1:1, the connector should be attached at - initialization time with a call to - drm_mode_connector_attach_encoder. The driver must - also set the drm_connector - encoder field to point to the attached - encoder. - - - Finally, drivers must initialize the connectors state change detection - with a call to drm_kms_helper_poll_init. If at - least one connector is pollable but can't generate hotplug interrupts - (indicated by the DRM_CONNECTOR_POLL_CONNECT and - DRM_CONNECTOR_POLL_DISCONNECT connector flags), a delayed work will - automatically be queued to periodically poll for changes. Connectors - that can generate hotplug interrupts must be marked with the - DRM_CONNECTOR_POLL_HPD flag instead, and their interrupt handler must - call drm_helper_hpd_irq_event. The function will - queue a delayed work to check the state of all connectors, but no - periodic polling will be done. - - - - Connector Operations - - Unless otherwise state, all operations are mandatory. - - - DPMS - void (*dpms)(struct drm_connector *connector, int mode); - - The DPMS operation sets the power state of a connector. The mode - argument is one of - - DRM_MODE_DPMS_ON - DRM_MODE_DPMS_STANDBY - DRM_MODE_DPMS_SUSPEND - DRM_MODE_DPMS_OFF - - - - In all but DPMS_ON mode the encoder to which the connector is attached - should put the display in low-power mode by driving its signals - appropriately. If more than one connector is attached to the encoder - care should be taken not to change the power state of other displays as - a side effect. Low-power mode should be propagated to the encoders and - CRTCs when all related connectors are put in low-power mode. - - - - Modes - int (*fill_modes)(struct drm_connector *connector, uint32_t max_width, - uint32_t max_height); - - Fill the mode list with all supported modes for the connector. If the - max_width and max_height - arguments are non-zero, the implementation must ignore all modes wider - than max_width or higher than - max_height. - - - The connector must also fill in this operation its - display_info - width_mm and - height_mm fields with the connected display - physical size in millimeters. The fields should be set to 0 if the value - isn't known or is not applicable (for instance for projector devices). - - - - Connection Status - - The connection status is updated through polling or hotplug events when - supported (see ). The status - value is reported to userspace through ioctls and must not be used - inside the driver, as it only gets initialized by a call to - drm_mode_getconnector from userspace. - - enum drm_connector_status (*detect)(struct drm_connector *connector, - bool force); - - Check to see if anything is attached to the connector. The - force parameter is set to false whilst polling or - to true when checking the connector due to user request. - force can be used by the driver to avoid - expensive, destructive operations during automated probing. - - - Return connector_status_connected if something is connected to the - connector, connector_status_disconnected if nothing is connected and - connector_status_unknown if the connection state isn't known. - - - Drivers should only return connector_status_connected if the connection - status has really been probed as connected. Connectors that can't detect - the connection status, or failed connection status probes, should return - connector_status_unknown. - - - - - - Cleanup - - The DRM core manages its objects' lifetime. When an object is not needed - anymore the core calls its destroy function, which must clean up and - free every resource allocated for the object. Every - drm_*_init call must be matched with a - corresponding drm_*_cleanup call to cleanup CRTCs - (drm_crtc_cleanup), planes - (drm_plane_cleanup), encoders - (drm_encoder_cleanup) and connectors - (drm_connector_cleanup). Furthermore, connectors - that have been added to sysfs must be removed by a call to - drm_connector_unregister before calling - drm_connector_cleanup. - - - Connectors state change detection must be cleanup up with a call to - drm_kms_helper_poll_fini. - - - - Output discovery and initialization example - base; - drm_connector_init(dev, &intel_output->base, - &intel_crt_connector_funcs, DRM_MODE_CONNECTOR_VGA); - - drm_encoder_init(dev, &intel_output->enc, &intel_crt_enc_funcs, - DRM_MODE_ENCODER_DAC); - - drm_mode_connector_attach_encoder(&intel_output->base, - &intel_output->enc); - - /* Set up the DDC bus. */ - intel_output->ddc_bus = intel_i2c_create(dev, GPIOA, "CRTDDC_A"); - if (!intel_output->ddc_bus) { - dev_printk(KERN_ERR, &dev->pdev->dev, "DDC bus registration " - "failed.\n"); - return; - } - - intel_output->type = INTEL_OUTPUT_ANALOG; - connector->interlace_allowed = 0; - connector->doublescan_allowed = 0; - - drm_encoder_helper_add(&intel_output->enc, &intel_crt_helper_funcs); - drm_connector_helper_add(connector, &intel_crt_connector_helper_funcs); - - drm_connector_register(connector); -}]]> - - In the example above (taken from the i915 driver), a CRTC, connector and - encoder combination is created. A device-specific i2c bus is also - created for fetching EDID data and performing monitor detection. Once - the process is complete, the new connector is registered with sysfs to - make its properties available to applications. - - - - KMS API Functions -!Edrivers/gpu/drm/drm_crtc.c - - - KMS Data Structures -!Iinclude/drm/drm_crtc.h - - - KMS Locking -!Pdrivers/gpu/drm/drm_modeset_lock.c kms locking -!Iinclude/drm/drm_modeset_lock.h -!Edrivers/gpu/drm/drm_modeset_lock.c - - - - - - - Mode Setting Helper Functions - - The plane, CRTC, encoder and connector functions provided by the drivers - implement the DRM API. They're called by the DRM core and ioctl handlers - to handle device state changes and configuration request. As implementing - those functions often requires logic not specific to drivers, mid-layer - helper functions are available to avoid duplicating boilerplate code. - - - The DRM core contains one mid-layer implementation. The mid-layer provides - implementations of several plane, CRTC, encoder and connector functions - (called from the top of the mid-layer) that pre-process requests and call - lower-level functions provided by the driver (at the bottom of the - mid-layer). For instance, the - drm_crtc_helper_set_config function can be used to - fill the struct drm_crtc_funcs - set_config field. When called, it will split - the set_config operation in smaller, simpler - operations and call the driver to handle them. - - - To use the mid-layer, drivers call drm_crtc_helper_add, - drm_encoder_helper_add and - drm_connector_helper_add functions to install their - mid-layer bottom operations handlers, and fill the - drm_crtc_funcs, - drm_encoder_funcs and - drm_connector_funcs structures with pointers to - the mid-layer top API functions. Installing the mid-layer bottom operation - handlers is best done right after registering the corresponding KMS object. - - - The mid-layer is not split between CRTC, encoder and connector operations. - To use it, a driver must provide bottom functions for all of the three KMS - entities. - - - Atomic Modeset Helper Functions Reference - - Overview -!Pdrivers/gpu/drm/drm_atomic_helper.c overview - - - Implementing Asynchronous Atomic Commit -!Pdrivers/gpu/drm/drm_atomic_helper.c implementing nonblocking commit - - - Atomic State Reset and Initialization -!Pdrivers/gpu/drm/drm_atomic_helper.c atomic state reset and initialization - -!Iinclude/drm/drm_atomic_helper.h -!Edrivers/gpu/drm/drm_atomic_helper.c - - - Modeset Helper Reference for Common Vtables -!Iinclude/drm/drm_modeset_helper_vtables.h -!Pinclude/drm/drm_modeset_helper_vtables.h overview - - - Legacy CRTC/Modeset Helper Functions Reference -!Edrivers/gpu/drm/drm_crtc_helper.c -!Pdrivers/gpu/drm/drm_crtc_helper.c overview - - - Output Probing Helper Functions Reference -!Pdrivers/gpu/drm/drm_probe_helper.c output probing helper overview -!Edrivers/gpu/drm/drm_probe_helper.c - - - fbdev Helper Functions Reference -!Pdrivers/gpu/drm/drm_fb_helper.c fbdev helpers -!Edrivers/gpu/drm/drm_fb_helper.c -!Iinclude/drm/drm_fb_helper.h - - - Framebuffer CMA Helper Functions Reference -!Pdrivers/gpu/drm/drm_fb_cma_helper.c framebuffer cma helper functions -!Edrivers/gpu/drm/drm_fb_cma_helper.c - - - Display Port Helper Functions Reference -!Pdrivers/gpu/drm/drm_dp_helper.c dp helpers -!Iinclude/drm/drm_dp_helper.h -!Edrivers/gpu/drm/drm_dp_helper.c - - - Display Port Dual Mode Adaptor Helper Functions Reference -!Pdrivers/gpu/drm/drm_dp_dual_mode_helper.c dp dual mode helpers -!Iinclude/drm/drm_dp_dual_mode_helper.h -!Edrivers/gpu/drm/drm_dp_dual_mode_helper.c - - - Display Port MST Helper Functions Reference -!Pdrivers/gpu/drm/drm_dp_mst_topology.c dp mst helper -!Iinclude/drm/drm_dp_mst_helper.h -!Edrivers/gpu/drm/drm_dp_mst_topology.c - - - MIPI DSI Helper Functions Reference -!Pdrivers/gpu/drm/drm_mipi_dsi.c dsi helpers -!Iinclude/drm/drm_mipi_dsi.h -!Edrivers/gpu/drm/drm_mipi_dsi.c - - - EDID Helper Functions Reference -!Edrivers/gpu/drm/drm_edid.c - - - Rectangle Utilities Reference -!Pinclude/drm/drm_rect.h rect utils -!Iinclude/drm/drm_rect.h -!Edrivers/gpu/drm/drm_rect.c - - - Flip-work Helper Reference -!Pinclude/drm/drm_flip_work.h flip utils -!Iinclude/drm/drm_flip_work.h -!Edrivers/gpu/drm/drm_flip_work.c - - - HDMI Infoframes Helper Reference - - Strictly speaking this is not a DRM helper library but generally useable - by any driver interfacing with HDMI outputs like v4l or alsa drivers. - But it nicely fits into the overall topic of mode setting helper - libraries and hence is also included here. - -!Iinclude/linux/hdmi.h -!Edrivers/video/hdmi.c - - - Plane Helper Reference -!Edrivers/gpu/drm/drm_plane_helper.c -!Pdrivers/gpu/drm/drm_plane_helper.c overview - - - Tile group -!Pdrivers/gpu/drm/drm_crtc.c Tile group - - - Bridges - - Overview -!Pdrivers/gpu/drm/drm_bridge.c overview - - - Default bridge callback sequence -!Pdrivers/gpu/drm/drm_bridge.c bridge callbacks - -!Edrivers/gpu/drm/drm_bridge.c - - - Panel Helper Reference -!Iinclude/drm/drm_panel.h -!Edrivers/gpu/drm/drm_panel.c -!Pdrivers/gpu/drm/drm_panel.c drm panel - - - Simple KMS Helper Reference -!Iinclude/drm/drm_simple_kms_helper.h -!Edrivers/gpu/drm/drm_simple_kms_helper.c -!Pdrivers/gpu/drm/drm_simple_kms_helper.c overview - - - - - - - KMS Properties - - Drivers may need to expose additional parameters to applications than - those described in the previous sections. KMS supports attaching - properties to CRTCs, connectors and planes and offers a userspace API to - list, get and set the property values. - - - Properties are identified by a name that uniquely defines the property - purpose, and store an associated value. For all property types except blob - properties the value is a 64-bit unsigned integer. - - - KMS differentiates between properties and property instances. Drivers - first create properties and then create and associate individual instances - of those properties to objects. A property can be instantiated multiple - times and associated with different objects. Values are stored in property - instances, and all other property information are stored in the property - and shared between all instances of the property. - - - Every property is created with a type that influences how the KMS core - handles the property. Supported property types are - - - DRM_MODE_PROP_RANGE - Range properties report their minimum and maximum - admissible values. The KMS core verifies that values set by - application fit in that range. - - - DRM_MODE_PROP_ENUM - Enumerated properties take a numerical value that - ranges from 0 to the number of enumerated values defined by the - property minus one, and associate a free-formed string name to each - value. Applications can retrieve the list of defined value-name pairs - and use the numerical value to get and set property instance values. - - - - DRM_MODE_PROP_BITMASK - Bitmask properties are enumeration properties that - additionally restrict all enumerated values to the 0..63 range. - Bitmask property instance values combine one or more of the - enumerated bits defined by the property. - - - DRM_MODE_PROP_BLOB - Blob properties store a binary blob without any format - restriction. The binary blobs are created as KMS standalone objects, - and blob property instance values store the ID of their associated - blob object. - Blob properties are only used for the connector EDID property - and cannot be created by drivers. - - - - - To create a property drivers call one of the following functions depending - on the property type. All property creation functions take property flags - and name, as well as type-specific arguments. - - - struct drm_property *drm_property_create_range(struct drm_device *dev, int flags, - const char *name, - uint64_t min, uint64_t max); - Create a range property with the given minimum and maximum - values. - - - struct drm_property *drm_property_create_enum(struct drm_device *dev, int flags, - const char *name, - const struct drm_prop_enum_list *props, - int num_values); - Create an enumerated property. The props - argument points to an array of num_values - value-name pairs. - - - struct drm_property *drm_property_create_bitmask(struct drm_device *dev, - int flags, const char *name, - const struct drm_prop_enum_list *props, - int num_values); - Create a bitmask property. The props - argument points to an array of num_values - value-name pairs. - - - - - Properties can additionally be created as immutable, in which case they - will be read-only for applications but can be modified by the driver. To - create an immutable property drivers must set the DRM_MODE_PROP_IMMUTABLE - flag at property creation time. - - - When no array of value-name pairs is readily available at property - creation time for enumerated or range properties, drivers can create - the property using the drm_property_create function - and manually add enumeration value-name pairs by calling the - drm_property_add_enum function. Care must be taken to - properly specify the property type through the flags - argument. - - - After creating properties drivers can attach property instances to CRTC, - connector and plane objects by calling the - drm_object_attach_property. The function takes a - pointer to the target object, a pointer to the previously created property - and an initial instance value. - - - Existing KMS Properties - - The following table gives description of drm properties exposed by various - modules/drivers. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Owner Module/DriversGroupProperty NameTypeProperty ValuesObject attachedDescription/Restrictions
DRMGeneric“rotation”BITMASK{ 0, "rotate-0" }, - { 1, "rotate-90" }, - { 2, "rotate-180" }, - { 3, "rotate-270" }, - { 4, "reflect-x" }, - { 5, "reflect-y" }CRTC, Planerotate-(degrees) rotates the image by the specified amount in degrees - in counter clockwise direction. reflect-x and reflect-y reflects the - image along the specified axis prior to rotation
“scaling mode”ENUM{ "None", "Full", "Center", "Full aspect" }ConnectorSupported by: amdgpu, gma500, i915, nouveau and radeon.
Connector“EDID”BLOB | IMMUTABLE0ConnectorContains id of edid blob ptr object.
“DPMS”ENUM{ “On”, “Standby”, “Suspend”, “Off” }ConnectorContains DPMS operation mode value.
“PATH”BLOB | IMMUTABLE0ConnectorContains topology path to a connector.
“TILE”BLOB | IMMUTABLE0ConnectorContains tiling information for a connector.
“CRTC_ID”OBJECTDRM_MODE_OBJECT_CRTCConnectorCRTC that connector is attached to (atomic)
Plane“type”ENUM | IMMUTABLE{ "Overlay", "Primary", "Cursor" }PlanePlane type
“SRC_X”RANGEMin=0, Max=UINT_MAXPlaneScanout source x coordinate in 16.16 fixed point (atomic)
“SRC_Y”RANGEMin=0, Max=UINT_MAXPlaneScanout source y coordinate in 16.16 fixed point (atomic)
“SRC_W”RANGEMin=0, Max=UINT_MAXPlaneScanout source width in 16.16 fixed point (atomic)
“SRC_H”RANGEMin=0, Max=UINT_MAXPlaneScanout source height in 16.16 fixed point (atomic)
“CRTC_X”SIGNED_RANGEMin=INT_MIN, Max=INT_MAXPlaneScanout CRTC (destination) x coordinate (atomic)
“CRTC_Y”SIGNED_RANGEMin=INT_MIN, Max=INT_MAXPlaneScanout CRTC (destination) y coordinate (atomic)
“CRTC_W”RANGEMin=0, Max=UINT_MAXPlaneScanout CRTC (destination) width (atomic)
“CRTC_H”RANGEMin=0, Max=UINT_MAXPlaneScanout CRTC (destination) height (atomic)
“FB_ID”OBJECTDRM_MODE_OBJECT_FBPlaneScanout framebuffer (atomic)
“CRTC_ID”OBJECTDRM_MODE_OBJECT_CRTCPlaneCRTC that plane is attached to (atomic)
DVI-I“subconnector”ENUM{ “Unknown”, “DVI-D”, “DVI-A” }ConnectorTBD
“select subconnector”ENUM{ “Automatic”, “DVI-D”, “DVI-A” }ConnectorTBD
TV“subconnector”ENUM{ "Unknown", "Composite", "SVIDEO", "Component", "SCART" }ConnectorTBD
“select subconnector”ENUM{ "Automatic", "Composite", "SVIDEO", "Component", "SCART" }ConnectorTBD
“mode”ENUM{ "NTSC_M", "NTSC_J", "NTSC_443", "PAL_B" } etc.ConnectorTBD
“left margin”RANGEMin=0, Max=100ConnectorTBD
“right margin”RANGEMin=0, Max=100ConnectorTBD
“top margin”RANGEMin=0, Max=100ConnectorTBD
“bottom margin”RANGEMin=0, Max=100ConnectorTBD
“brightness”RANGEMin=0, Max=100ConnectorTBD
“contrast”RANGEMin=0, Max=100ConnectorTBD
“flicker reduction”RANGEMin=0, Max=100ConnectorTBD
“overscan”RANGEMin=0, Max=100ConnectorTBD
“saturation”RANGEMin=0, Max=100ConnectorTBD
“hue”RANGEMin=0, Max=100ConnectorTBD
Virtual GPU“suggested X”RANGEMin=0, Max=0xffffffffConnectorproperty to suggest an X offset for a connector
“suggested Y”RANGEMin=0, Max=0xffffffffConnectorproperty to suggest an Y offset for a connector
Optional"aspect ratio"ENUM{ "None", "4:3", "16:9" }ConnectorTDB
“dirty”ENUM | IMMUTABLE{ "Off", "On", "Annotate" }ConnectorTBD
“DEGAMMA_LUT”BLOB0CRTCDRM property to set the degamma lookup table - (LUT) mapping pixel data from the framebuffer before it is - given to the transformation matrix. The data is an interpreted - as an array of struct drm_color_lut elements. Hardware might - choose not to use the full precision of the LUT elements nor - use all the elements of the LUT (for example the hardware - might choose to interpolate between LUT[0] and LUT[4]).
“DEGAMMA_LUT_SIZE”RANGE | IMMUTABLEMin=0, Max=UINT_MAXCRTCDRM property to gives the size of the lookup - table to be set on the DEGAMMA_LUT property (the size depends - on the underlying hardware).
“CTM”BLOB0CRTCDRM property to set the current - transformation matrix (CTM) apply to pixel data after the - lookup through the degamma LUT and before the lookup through - the gamma LUT. The data is an interpreted as a struct - drm_color_ctm.
“GAMMA_LUT”BLOB0CRTCDRM property to set the gamma lookup table - (LUT) mapping pixel data after to the transformation matrix to - data sent to the connector. The data is an interpreted as an - array of struct drm_color_lut elements. Hardware might choose - not to use the full precision of the LUT elements nor use all - the elements of the LUT (for example the hardware might choose - to interpolate between LUT[0] and LUT[4]).
“GAMMA_LUT_SIZE”RANGE | IMMUTABLEMin=0, Max=UINT_MAXCRTCDRM property to gives the size of the lookup - table to be set on the GAMMA_LUT property (the size depends on - the underlying hardware).
i915Generic"Broadcast RGB"ENUM{ "Automatic", "Full", "Limited 16:235" }ConnectorWhen this property is set to Limited 16:235 - and CTM is set, the hardware will be programmed with the - result of the multiplication of CTM by the limited range - matrix to ensure the pixels normaly in the range 0..1.0 are - remapped to the range 16/255..235/255.
“audio”ENUM{ "force-dvi", "off", "auto", "on" }ConnectorTBD
SDVO-TV“mode”ENUM{ "NTSC_M", "NTSC_J", "NTSC_443", "PAL_B" } etc.ConnectorTBD
"left_margin"RANGEMin=0, Max= SDVO dependentConnectorTBD
"right_margin"RANGEMin=0, Max= SDVO dependentConnectorTBD
"top_margin"RANGEMin=0, Max= SDVO dependentConnectorTBD
"bottom_margin"RANGEMin=0, Max= SDVO dependentConnectorTBD
“hpos”RANGEMin=0, Max= SDVO dependentConnectorTBD
“vpos”RANGEMin=0, Max= SDVO dependentConnectorTBD
“contrast”RANGEMin=0, Max= SDVO dependentConnectorTBD
“saturation”RANGEMin=0, Max= SDVO dependentConnectorTBD
“hue”RANGEMin=0, Max= SDVO dependentConnectorTBD
“sharpness”RANGEMin=0, Max= SDVO dependentConnectorTBD
“flicker_filter”RANGEMin=0, Max= SDVO dependentConnectorTBD
“flicker_filter_adaptive”RANGEMin=0, Max= SDVO dependentConnectorTBD
“flicker_filter_2d”RANGEMin=0, Max= SDVO dependentConnectorTBD
“tv_chroma_filter”RANGEMin=0, Max= SDVO dependentConnectorTBD
“tv_luma_filter”RANGEMin=0, Max= SDVO dependentConnectorTBD
“dot_crawl”RANGEMin=0, Max=1ConnectorTBD
SDVO-TV/LVDS“brightness”RANGEMin=0, Max= SDVO dependentConnectorTBD
CDV gma-500Generic"Broadcast RGB"ENUM{ “Full”, “Limited 16:235” }ConnectorTBD
"Broadcast RGB"ENUM{ “off”, “auto”, “on” }ConnectorTBD
PoulsboGeneric“backlight”RANGEMin=0, Max=100ConnectorTBD
SDVO-TV“mode”ENUM{ "NTSC_M", "NTSC_J", "NTSC_443", "PAL_B" } etc.ConnectorTBD
"left_margin"RANGEMin=0, Max= SDVO dependentConnectorTBD
"right_margin"RANGEMin=0, Max= SDVO dependentConnectorTBD
"top_margin"RANGEMin=0, Max= SDVO dependentConnectorTBD
"bottom_margin"RANGEMin=0, Max= SDVO dependentConnectorTBD
“hpos”RANGEMin=0, Max= SDVO dependentConnectorTBD
“vpos”RANGEMin=0, Max= SDVO dependentConnectorTBD
“contrast”RANGEMin=0, Max= SDVO dependentConnectorTBD
“saturation”RANGEMin=0, Max= SDVO dependentConnectorTBD
“hue”RANGEMin=0, Max= SDVO dependentConnectorTBD
“sharpness”RANGEMin=0, Max= SDVO dependentConnectorTBD
“flicker_filter”RANGEMin=0, Max= SDVO dependentConnectorTBD
“flicker_filter_adaptive”RANGEMin=0, Max= SDVO dependentConnectorTBD
“flicker_filter_2d”RANGEMin=0, Max= SDVO dependentConnectorTBD
“tv_chroma_filter”RANGEMin=0, Max= SDVO dependentConnectorTBD
“tv_luma_filter”RANGEMin=0, Max= SDVO dependentConnectorTBD
“dot_crawl”RANGEMin=0, Max=1ConnectorTBD
SDVO-TV/LVDS“brightness”RANGEMin=0, Max= SDVO dependentConnectorTBD
armadaCRTC"CSC_YUV"ENUM{ "Auto" , "CCIR601", "CCIR709" }CRTCTBD
"CSC_RGB"ENUM{ "Auto", "Computer system", "Studio" }CRTCTBD
Overlay"colorkey"RANGEMin=0, Max=0xffffffPlaneTBD
"colorkey_min"RANGEMin=0, Max=0xffffffPlaneTBD
"colorkey_max"RANGEMin=0, Max=0xffffffPlaneTBD
"colorkey_val"RANGEMin=0, Max=0xffffffPlaneTBD
"colorkey_alpha"RANGEMin=0, Max=0xffffffPlaneTBD
"colorkey_mode"ENUM{ "disabled", "Y component", "U component" - , "V component", "RGB", “R component", "G component", "B component" }PlaneTBD
"brightness"RANGEMin=0, Max=256 + 255PlaneTBD
"contrast"RANGEMin=0, Max=0x7fffPlaneTBD
"saturation"RANGEMin=0, Max=0x7fffPlaneTBD
exynosCRTC“mode”ENUM{ "normal", "blank" }CRTCTBD
Overlay“zpos”RANGEMin=0, Max=MAX_PLANE-1PlaneTBD
i2c/ch7006_drvGeneric“scale”RANGEMin=0, Max=2ConnectorTBD
TV“mode”ENUM{ "PAL", "PAL-M","PAL-N"}, ”PAL-Nc" - , "PAL-60", "NTSC-M", "NTSC-J" }ConnectorTBD
nouveauNV10 Overlay"colorkey"RANGEMin=0, Max=0x01ffffffPlaneTBD
“contrast”RANGEMin=0, Max=8192-1PlaneTBD
“brightness”RANGEMin=0, Max=1024PlaneTBD
“hue”RANGEMin=0, Max=359PlaneTBD
“saturation”RANGEMin=0, Max=8192-1PlaneTBD
“iturbt_709”RANGEMin=0, Max=1PlaneTBD
Nv04 Overlay“colorkey”RANGEMin=0, Max=0x01ffffffPlaneTBD
“brightness”RANGEMin=0, Max=1024PlaneTBD
Display“dithering mode”ENUM{ "auto", "off", "on" }ConnectorTBD
“dithering depth”ENUM{ "auto", "off", "on", "static 2x2", "dynamic 2x2", "temporal" }ConnectorTBD
“underscan”ENUM{ "auto", "6 bpc", "8 bpc" }ConnectorTBD
“underscan hborder”RANGEMin=0, Max=128ConnectorTBD
“underscan vborder”RANGEMin=0, Max=128ConnectorTBD
“vibrant hue”RANGEMin=0, Max=180ConnectorTBD
“color vibrance”RANGEMin=0, Max=200ConnectorTBD
omapGeneric“zorder”RANGEMin=0, Max=3CRTC, PlaneTBD
qxlGeneric“hotplug_mode_update"RANGEMin=0, Max=1ConnectorTBD
radeonDVI-I“coherent”RANGEMin=0, Max=1ConnectorTBD
DAC enable load detect“load detection”RANGEMin=0, Max=1ConnectorTBD
TV Standard"tv standard"ENUM{ "ntsc", "pal", "pal-m", "pal-60", "ntsc-j" - , "scart-pal", "pal-cn", "secam" }ConnectorTBD
legacy TMDS PLL detect"tmds_pll"ENUM{ "driver", "bios" }-TBD
Underscan"underscan"ENUM{ "off", "on", "auto" }ConnectorTBD
"underscan hborder"RANGEMin=0, Max=128ConnectorTBD
"underscan vborder"RANGEMin=0, Max=128ConnectorTBD
Audio“audio”ENUM{ "off", "on", "auto" }ConnectorTBD
FMT Dithering“dither”ENUM{ "off", "on" }ConnectorTBD
rcar-duGeneric"alpha"RANGEMin=0, Max=255PlaneTBD
"colorkey"RANGEMin=0, Max=0x01ffffffPlaneTBD
"zpos"RANGEMin=1, Max=7PlaneTBD
- - - - - - - Vertical Blanking - - Vertical blanking plays a major role in graphics rendering. To achieve - tear-free display, users must synchronize page flips and/or rendering to - vertical blanking. The DRM API offers ioctls to perform page flips - synchronized to vertical blanking and wait for vertical blanking. - - - The DRM core handles most of the vertical blanking management logic, which - involves filtering out spurious interrupts, keeping race-free blanking - counters, coping with counter wrap-around and resets and keeping use - counts. It relies on the driver to generate vertical blanking interrupts - and optionally provide a hardware vertical blanking counter. Drivers must - implement the following operations. - - - - int (*enable_vblank) (struct drm_device *dev, int crtc); -void (*disable_vblank) (struct drm_device *dev, int crtc); - - Enable or disable vertical blanking interrupts for the given CRTC. - - - - u32 (*get_vblank_counter) (struct drm_device *dev, int crtc); - - Retrieve the value of the vertical blanking counter for the given - CRTC. If the hardware maintains a vertical blanking counter its value - should be returned. Otherwise drivers can use the - drm_vblank_count helper function to handle this - operation. - - - - - Drivers must initialize the vertical blanking handling core with a call to - drm_vblank_init in their - load operation. - - - Vertical blanking interrupts can be enabled by the DRM core or by drivers - themselves (for instance to handle page flipping operations). The DRM core - maintains a vertical blanking use count to ensure that the interrupts are - not disabled while a user still needs them. To increment the use count, - drivers call drm_vblank_get. Upon return vertical - blanking interrupts are guaranteed to be enabled. - - - To decrement the use count drivers call - drm_vblank_put. Only when the use count drops to zero - will the DRM core disable the vertical blanking interrupts after a delay - by scheduling a timer. The delay is accessible through the vblankoffdelay - module parameter or the drm_vblank_offdelay global - variable and expressed in milliseconds. Its default value is 5000 ms. - Zero means never disable, and a negative value means disable immediately. - Drivers may override the behaviour by setting the - drm_device - vblank_disable_immediate flag, which when set - causes vblank interrupts to be disabled immediately regardless of the - drm_vblank_offdelay value. The flag should only be set if there's a - properly working hardware vblank counter present. - - - When a vertical blanking interrupt occurs drivers only need to call the - drm_handle_vblank function to account for the - interrupt. - - - Resources allocated by drm_vblank_init must be freed - with a call to drm_vblank_cleanup in the driver - unload operation handler. - - - Vertical Blanking and Interrupt Handling Functions Reference -!Edrivers/gpu/drm/drm_irq.c -!Finclude/drm/drmP.h drm_crtc_vblank_waitqueue - - - - - - - Open/Close, File Operations and IOCTLs - - Open and Close - int (*firstopen) (struct drm_device *); -void (*lastclose) (struct drm_device *); -int (*open) (struct drm_device *, struct drm_file *); -void (*preclose) (struct drm_device *, struct drm_file *); -void (*postclose) (struct drm_device *, struct drm_file *); - Open and close handlers. None of those methods are mandatory. - - - The firstopen method is called by the DRM core - for legacy UMS (User Mode Setting) drivers only when an application - opens a device that has no other opened file handle. UMS drivers can - implement it to acquire device resources. KMS drivers can't use the - method and must acquire resources in the load - method instead. - - - Similarly the lastclose method is called when - the last application holding a file handle opened on the device closes - it, for both UMS and KMS drivers. Additionally, the method is also - called at module unload time or, for hot-pluggable devices, when the - device is unplugged. The firstopen and - lastclose calls can thus be unbalanced. - - - The open method is called every time the device - is opened by an application. Drivers can allocate per-file private data - in this method and store them in the struct - drm_file driver_priv - field. Note that the open method is called - before firstopen. - - - The close operation is split into preclose and - postclose methods. Drivers must stop and - cleanup all per-file operations in the preclose - method. For instance pending vertical blanking and page flip events must - be cancelled. No per-file operation is allowed on the file handle after - returning from the preclose method. - - - Finally the postclose method is called as the - last step of the close operation, right before calling the - lastclose method if no other open file handle - exists for the device. Drivers that have allocated per-file private data - in the open method should free it here. - - - The lastclose method should restore CRTC and - plane properties to default value, so that a subsequent open of the - device will not inherit state from the previous user. It can also be - used to execute delayed power switching state changes, e.g. in - conjunction with the vga_switcheroo infrastructure (see - ). Beyond that KMS drivers should not - do any further cleanup. Only legacy UMS drivers might need to clean up - device state so that the vga console or an independent fbdev driver - could take over. - - - - File Operations -!Pdrivers/gpu/drm/drm_fops.c file operations -!Edrivers/gpu/drm/drm_fops.c - - - IOCTLs - struct drm_ioctl_desc *ioctls; -int num_ioctls; - Driver-specific ioctls descriptors table. - - Driver-specific ioctls numbers start at DRM_COMMAND_BASE. The ioctls - descriptors table is indexed by the ioctl number offset from the base - value. Drivers can use the DRM_IOCTL_DEF_DRV() macro to initialize the - table entries. - - - DRM_IOCTL_DEF_DRV(ioctl, func, flags) - - ioctl is the ioctl name. Drivers must define - the DRM_##ioctl and DRM_IOCTL_##ioctl macros to the ioctl number - offset from DRM_COMMAND_BASE and the ioctl number respectively. The - first macro is private to the device while the second must be exposed - to userspace in a public header. - - - func is a pointer to the ioctl handler function - compatible with the drm_ioctl_t type. - typedef int drm_ioctl_t(struct drm_device *dev, void *data, - struct drm_file *file_priv); - - - flags is a bitmask combination of the following - values. It restricts how the ioctl is allowed to be called. - - - DRM_AUTH - Only authenticated callers allowed - - - DRM_MASTER - The ioctl can only be called on the master file - handle - - - DRM_ROOT_ONLY - Only callers with the SYSADMIN capability allowed - - - DRM_CONTROL_ALLOW - The ioctl can only be called on a control - device - - - DRM_UNLOCKED - The ioctl handler will be called without locking - the DRM global mutex. This is the enforced default for kms drivers - (i.e. using the DRIVER_MODESET flag) and hence shouldn't be used - any more for new drivers. - - - - -!Edrivers/gpu/drm/drm_ioctl.c - - - - Legacy Support Code - - The section very briefly covers some of the old legacy support code which - is only used by old DRM drivers which have done a so-called shadow-attach - to the underlying device instead of registering as a real driver. This - also includes some of the old generic buffer management and command - submission code. Do not use any of this in new and modern drivers. - - - - Legacy Suspend/Resume - - The DRM core provides some suspend/resume code, but drivers wanting full - suspend/resume support should provide save() and restore() functions. - These are called at suspend, hibernate, or resume time, and should perform - any state save or restore required by your device across suspend or - hibernate states. - - int (*suspend) (struct drm_device *, pm_message_t state); - int (*resume) (struct drm_device *); - - Those are legacy suspend and resume methods which - only work with the legacy shadow-attach driver - registration functions. New driver should use the power management - interface provided by their bus type (usually through - the struct device_driver dev_pm_ops) and set - these methods to NULL. - - - - - Legacy DMA Services - - This should cover how DMA mapping etc. is supported by the core. - These functions are deprecated and should not be used. - - - - - - - - - - - Userland interfaces - - The DRM core exports several interfaces to applications, - generally intended to be used through corresponding libdrm - wrapper functions. In addition, drivers export device-specific - interfaces for use by userspace drivers & device-aware - applications through ioctls and sysfs files. - - - External interfaces include: memory mapping, context management, - DMA operations, AGP management, vblank control, fence - management, memory management, and output management. - - - Cover generic ioctls and sysfs layout here. We only need high-level - info, since man pages should cover the rest. - - - - - - Render nodes - - DRM core provides multiple character-devices for user-space to use. - Depending on which device is opened, user-space can perform a different - set of operations (mainly ioctls). The primary node is always created - and called card<num>. Additionally, a currently - unused control node, called controlD<num> is also - created. The primary node provides all legacy operations and - historically was the only interface used by userspace. With KMS, the - control node was introduced. However, the planned KMS control interface - has never been written and so the control node stays unused to date. - - - With the increased use of offscreen renderers and GPGPU applications, - clients no longer require running compositors or graphics servers to - make use of a GPU. But the DRM API required unprivileged clients to - authenticate to a DRM-Master prior to getting GPU access. To avoid this - step and to grant clients GPU access without authenticating, render - nodes were introduced. Render nodes solely serve render clients, that - is, no modesetting or privileged ioctls can be issued on render nodes. - Only non-global rendering commands are allowed. If a driver supports - render nodes, it must advertise it via the DRIVER_RENDER - DRM driver capability. If not supported, the primary node must be used - for render clients together with the legacy drmAuth authentication - procedure. - - - If a driver advertises render node support, DRM core will create a - separate render node called renderD<num>. There will - be one render node per device. No ioctls except PRIME-related ioctls - will be allowed on this node. Especially GEM_OPEN will be - explicitly prohibited. Render nodes are designed to avoid the - buffer-leaks, which occur if clients guess the flink names or mmap - offsets on the legacy interface. Additionally to this basic interface, - drivers must mark their driver-dependent render-only ioctls as - DRM_RENDER_ALLOW so render clients can use them. Driver - authors must be careful not to allow any privileged ioctls on render - nodes. - - - With render nodes, user-space can now control access to the render node - via basic file-system access-modes. A running graphics server which - authenticates clients on the privileged primary/legacy node is no longer - required. Instead, a client can open the render node and is immediately - granted GPU access. Communication between clients (or servers) is done - via PRIME. FLINK from render node to legacy node is not supported. New - clients must not use the insecure FLINK interface. - - - Besides dropping all modeset/global ioctls, render nodes also drop the - DRM-Master concept. There is no reason to associate render clients with - a DRM-Master as they are independent of any graphics server. Besides, - they must work without any running master, anyway. - Drivers must be able to run without a master object if they support - render nodes. If, on the other hand, a driver requires shared state - between clients which is visible to user-space and accessible beyond - open-file boundaries, they cannot support render nodes. - - - - - - - VBlank event handling - - The DRM core exposes two vertical blank related ioctls: - - - DRM_IOCTL_WAIT_VBLANK - - - This takes a struct drm_wait_vblank structure as its argument, - and it is used to block or request a signal when a specified - vblank event occurs. - - - - - DRM_IOCTL_MODESET_CTL - - - This was only used for user-mode-settind drivers around - modesetting changes to allow the kernel to update the vblank - interrupt after mode setting, since on many devices the vertical - blank counter is reset to 0 at some point during modeset. Modern - drivers should not call this any more since with kernel mode - setting it is a no-op. - - - - - - - - - - - DRM Drivers - - - - This second part of the GPU Driver Developer's Guide documents driver - code, implementation details and also all the driver-specific userspace - interfaces. Especially since all hardware-acceleration interfaces to - userspace are driver specific for efficiency and other reasons these - interfaces can be rather substantial. Hence every driver has its own - chapter. - - - - - drm/i915 Intel GFX Driver - - The drm/i915 driver supports all (with the exception of some very early - models) integrated GFX chipsets with both Intel display and rendering - blocks. This excludes a set of SoC platforms with an SGX rendering unit, - those have basic support through the gma500 drm driver. - - - Core Driver Infrastructure - - This section covers core driver infrastructure used by both the display - and the GEM parts of the driver. - - - Runtime Power Management -!Pdrivers/gpu/drm/i915/intel_runtime_pm.c runtime pm -!Idrivers/gpu/drm/i915/intel_runtime_pm.c -!Idrivers/gpu/drm/i915/intel_uncore.c - - - Interrupt Handling -!Pdrivers/gpu/drm/i915/i915_irq.c interrupt handling -!Fdrivers/gpu/drm/i915/i915_irq.c intel_irq_init intel_irq_init_hw intel_hpd_init -!Fdrivers/gpu/drm/i915/i915_irq.c intel_runtime_pm_disable_interrupts -!Fdrivers/gpu/drm/i915/i915_irq.c intel_runtime_pm_enable_interrupts - - - Intel GVT-g Guest Support(vGPU) -!Pdrivers/gpu/drm/i915/i915_vgpu.c Intel GVT-g guest support -!Idrivers/gpu/drm/i915/i915_vgpu.c - - - - Display Hardware Handling - - This section covers everything related to the display hardware including - the mode setting infrastructure, plane, sprite and cursor handling and - display, output probing and related topics. - - - Mode Setting Infrastructure - - The i915 driver is thus far the only DRM driver which doesn't use the - common DRM helper code to implement mode setting sequences. Thus it - has its own tailor-made infrastructure for executing a display - configuration change. - - - - Frontbuffer Tracking -!Pdrivers/gpu/drm/i915/intel_frontbuffer.c frontbuffer tracking -!Idrivers/gpu/drm/i915/intel_frontbuffer.c -!Fdrivers/gpu/drm/i915/i915_gem.c i915_gem_track_fb - - - Display FIFO Underrun Reporting -!Pdrivers/gpu/drm/i915/intel_fifo_underrun.c fifo underrun handling -!Idrivers/gpu/drm/i915/intel_fifo_underrun.c - - - Plane Configuration - - This section covers plane configuration and composition with the - primary plane, sprites, cursors and overlays. This includes the - infrastructure to do atomic vsync'ed updates of all this state and - also tightly coupled topics like watermark setup and computation, - framebuffer compression and panel self refresh. - - - - Atomic Plane Helpers -!Pdrivers/gpu/drm/i915/intel_atomic_plane.c atomic plane helpers -!Idrivers/gpu/drm/i915/intel_atomic_plane.c - - - Output Probing - - This section covers output probing and related infrastructure like the - hotplug interrupt storm detection and mitigation code. Note that the - i915 driver still uses most of the common DRM helper code for output - probing, so those sections fully apply. - - - - Hotplug -!Pdrivers/gpu/drm/i915/intel_hotplug.c Hotplug -!Idrivers/gpu/drm/i915/intel_hotplug.c - - - High Definition Audio -!Pdrivers/gpu/drm/i915/intel_audio.c High Definition Audio over HDMI and Display Port -!Idrivers/gpu/drm/i915/intel_audio.c -!Iinclude/drm/i915_component.h - - - Panel Self Refresh PSR (PSR/SRD) -!Pdrivers/gpu/drm/i915/intel_psr.c Panel Self Refresh (PSR/SRD) -!Idrivers/gpu/drm/i915/intel_psr.c - - - Frame Buffer Compression (FBC) -!Pdrivers/gpu/drm/i915/intel_fbc.c Frame Buffer Compression (FBC) -!Idrivers/gpu/drm/i915/intel_fbc.c - - - Display Refresh Rate Switching (DRRS) -!Pdrivers/gpu/drm/i915/intel_dp.c Display Refresh Rate Switching (DRRS) -!Fdrivers/gpu/drm/i915/intel_dp.c intel_dp_set_drrs_state -!Fdrivers/gpu/drm/i915/intel_dp.c intel_edp_drrs_enable -!Fdrivers/gpu/drm/i915/intel_dp.c intel_edp_drrs_disable -!Fdrivers/gpu/drm/i915/intel_dp.c intel_edp_drrs_invalidate -!Fdrivers/gpu/drm/i915/intel_dp.c intel_edp_drrs_flush -!Fdrivers/gpu/drm/i915/intel_dp.c intel_dp_drrs_init - - - - DPIO -!Pdrivers/gpu/drm/i915/i915_reg.h DPIO - - - - CSR firmware support for DMC -!Pdrivers/gpu/drm/i915/intel_csr.c csr support for dmc -!Idrivers/gpu/drm/i915/intel_csr.c - - - Video BIOS Table (VBT) -!Pdrivers/gpu/drm/i915/intel_bios.c Video BIOS Table (VBT) -!Idrivers/gpu/drm/i915/intel_bios.c -!Idrivers/gpu/drm/i915/intel_vbt_defs.h - - - - - Memory Management and Command Submission - - This sections covers all things related to the GEM implementation in the - i915 driver. - - - Batchbuffer Parsing -!Pdrivers/gpu/drm/i915/i915_cmd_parser.c batch buffer command parser -!Idrivers/gpu/drm/i915/i915_cmd_parser.c - - - Batchbuffer Pools -!Pdrivers/gpu/drm/i915/i915_gem_batch_pool.c batch pool -!Idrivers/gpu/drm/i915/i915_gem_batch_pool.c - - - Logical Rings, Logical Ring Contexts and Execlists -!Pdrivers/gpu/drm/i915/intel_lrc.c Logical Rings, Logical Ring Contexts and Execlists -!Idrivers/gpu/drm/i915/intel_lrc.c - - - Global GTT views -!Pdrivers/gpu/drm/i915/i915_gem_gtt.c Global GTT views -!Idrivers/gpu/drm/i915/i915_gem_gtt.c - - - GTT Fences and Swizzling -!Idrivers/gpu/drm/i915/i915_gem_fence.c - - Global GTT Fence Handling -!Pdrivers/gpu/drm/i915/i915_gem_fence.c fence register handling - - - Hardware Tiling and Swizzling Details -!Pdrivers/gpu/drm/i915/i915_gem_fence.c tiling swizzling details - - - - Object Tiling IOCTLs -!Idrivers/gpu/drm/i915/i915_gem_tiling.c -!Pdrivers/gpu/drm/i915/i915_gem_tiling.c buffer object tiling - - - Buffer Object Eviction - - This section documents the interface functions for evicting buffer - objects to make space available in the virtual gpu address spaces. - Note that this is mostly orthogonal to shrinking buffer objects - caches, which has the goal to make main memory (shared with the gpu - through the unified memory architecture) available. - -!Idrivers/gpu/drm/i915/i915_gem_evict.c - - - Buffer Object Memory Shrinking - - This section documents the interface function for shrinking memory - usage of buffer object caches. Shrinking is used to make main memory - available. Note that this is mostly orthogonal to evicting buffer - objects, which has the goal to make space in gpu virtual address - spaces. - -!Idrivers/gpu/drm/i915/i915_gem_shrinker.c - - - - GuC - - GuC-specific firmware loader -!Pdrivers/gpu/drm/i915/intel_guc_loader.c GuC-specific firmware loader -!Idrivers/gpu/drm/i915/intel_guc_loader.c - - - GuC-based command submission -!Pdrivers/gpu/drm/i915/i915_guc_submission.c GuC-based command submission -!Idrivers/gpu/drm/i915/i915_guc_submission.c - - - GuC Firmware Layout -!Pdrivers/gpu/drm/i915/intel_guc_fwif.h GuC Firmware Layout - - - - - Tracing - - This sections covers all things related to the tracepoints implemented in - the i915 driver. - - - i915_ppgtt_create and i915_ppgtt_release -!Pdrivers/gpu/drm/i915/i915_trace.h i915_ppgtt_create and i915_ppgtt_release tracepoints - - - i915_context_create and i915_context_free -!Pdrivers/gpu/drm/i915/i915_trace.h i915_context_create and i915_context_free tracepoints - - - switch_mm -!Pdrivers/gpu/drm/i915/i915_trace.h switch_mm tracepoint - - - - -!Cdrivers/gpu/drm/i915/i915_irq.c - - - - vga_switcheroo - -!Pdrivers/gpu/vga/vga_switcheroo.c Overview - - - - Modes of Use - - Manual switching and manual power control -!Pdrivers/gpu/vga/vga_switcheroo.c Manual switching and manual power control - - - Driver power control -!Pdrivers/gpu/vga/vga_switcheroo.c Driver power control - - - - - API - - Public functions -!Edrivers/gpu/vga/vga_switcheroo.c - - - Public structures -!Finclude/linux/vga_switcheroo.h vga_switcheroo_handler -!Finclude/linux/vga_switcheroo.h vga_switcheroo_client_ops - - - Public constants -!Finclude/linux/vga_switcheroo.h vga_switcheroo_handler_flags_t -!Finclude/linux/vga_switcheroo.h vga_switcheroo_client_id -!Finclude/linux/vga_switcheroo.h vga_switcheroo_state - - - Private structures -!Fdrivers/gpu/vga/vga_switcheroo.c vgasr_priv -!Fdrivers/gpu/vga/vga_switcheroo.c vga_switcheroo_client - - - - - Handlers - - apple-gmux Handler -!Pdrivers/platform/x86/apple-gmux.c Overview -!Pdrivers/platform/x86/apple-gmux.c Interrupt - - Graphics mux -!Pdrivers/platform/x86/apple-gmux.c Graphics mux - - - Power control -!Pdrivers/platform/x86/apple-gmux.c Power control - - - Backlight control -!Pdrivers/platform/x86/apple-gmux.c Backlight control - - - Public functions -!Iinclude/linux/apple-gmux.h - - - - -!Cdrivers/gpu/vga/vga_switcheroo.c -!Cinclude/linux/vga_switcheroo.h -!Cdrivers/platform/x86/apple-gmux.c - - - diff --git a/Documentation/devicetree/bindings/display/arm,malidp.txt b/Documentation/devicetree/bindings/display/arm,malidp.txt new file mode 100644 index 000000000000..2f7870983ef1 --- /dev/null +++ b/Documentation/devicetree/bindings/display/arm,malidp.txt @@ -0,0 +1,65 @@ +ARM Mali-DP + +The following bindings apply to a family of Display Processors sold as +licensable IP by ARM Ltd. The bindings describe the Mali DP500, DP550 and +DP650 processors that offer multiple composition layers, support for +rotation and scaling output. + +Required properties: + - compatible: should be one of + "arm,mali-dp500" + "arm,mali-dp550" + "arm,mali-dp650" + depending on the particular implementation present in the hardware + - reg: Physical base address and size of the block of registers used by + the processor. + - interrupts: Interrupt list, as defined in ../interrupt-controller/interrupts.txt, + interrupt client nodes. + - interrupt-names: name of the engine inside the processor that will + use the corresponding interrupt. Should be one of "DE" or "SE". + - clocks: A list of phandle + clock-specifier pairs, one for each entry + in 'clock-names' + - clock-names: A list of clock names. It should contain: + - "pclk": for the APB interface clock + - "aclk": for the AXI interface clock + - "mclk": for the main processor clock + - "pxlclk": for the pixel clock feeding the output PLL of the processor. + - arm,malidp-output-port-lines: Array of u8 values describing the number + of output lines per channel (R, G and B). + +Required sub-nodes: + - port: The Mali DP connection to an encoder input port. The connection + is modelled using the OF graph bindings specified in + Documentation/devicetree/bindings/graph.txt + +Optional properties: + - memory-region: phandle to a node describing memory (see + Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt) + to be used for the framebuffer; if not present, the framebuffer may + be located anywhere in memory. + + +Example: + +/ { + ... + + dp0: malidp@6f200000 { + compatible = "arm,mali-dp650"; + reg = <0 0x6f200000 0 0x20000>; + memory-region = <&display_reserved>; + interrupts = <0 168 IRQ_TYPE_LEVEL_HIGH>, + <0 168 IRQ_TYPE_LEVEL_HIGH>; + interrupt-names = "DE", "SE"; + clocks = <&oscclk2>, <&fpgaosc0>, <&fpgaosc1>, <&fpgaosc1>; + clock-names = "pxlclk", "mclk", "aclk", "pclk"; + arm,malidp-output-port-lines = /bits/ 8 <8 8 8>; + port { + dp0_output: endpoint { + remote-endpoint = <&tda998x_2_input>; + }; + }; + }; + + ... +}; diff --git a/Documentation/devicetree/bindings/display/bridge/sii902x.txt b/Documentation/devicetree/bindings/display/bridge/sii902x.txt new file mode 100644 index 000000000000..56a3e68ccb80 --- /dev/null +++ b/Documentation/devicetree/bindings/display/bridge/sii902x.txt @@ -0,0 +1,35 @@ +sii902x HDMI bridge bindings + +Required properties: + - compatible: "sil,sii9022" + - reg: i2c address of the bridge + +Optional properties: + - interrupts-extended or interrupt-parent + interrupts: describe + the interrupt line used to inform the host about hotplug events. + - reset-gpios: OF device-tree gpio specification for RST_N pin. + +Optional subnodes: + - video input: this subnode can contain a video input port node + to connect the bridge to a display controller output (See this + documentation [1]). + +[1]: Documentation/devicetree/bindings/media/video-interfaces.txt + +Example: + hdmi-bridge@39 { + compatible = "sil,sii9022"; + reg = <0x39>; + reset-gpios = <&pioA 1 0>; + ports { + #address-cells = <1>; + #size-cells = <0>; + + port@0 { + reg = <0>; + bridge_in: endpoint { + remote-endpoint = <&dc_out>; + }; + }; + }; + }; diff --git a/Documentation/devicetree/bindings/display/connector/hdmi-connector.txt b/Documentation/devicetree/bindings/display/connector/hdmi-connector.txt index acd5668b1ce1..508aee461e0d 100644 --- a/Documentation/devicetree/bindings/display/connector/hdmi-connector.txt +++ b/Documentation/devicetree/bindings/display/connector/hdmi-connector.txt @@ -8,6 +8,7 @@ Required properties: Optional properties: - label: a symbolic name for the connector - hpd-gpios: HPD GPIO number +- ddc-i2c-bus: phandle link to the I2C controller used for DDC EDID probing Required nodes: - Video port for HDMI input diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,hdmi.txt b/Documentation/devicetree/bindings/display/mediatek/mediatek,hdmi.txt new file mode 100644 index 000000000000..7b124242b0c5 --- /dev/null +++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,hdmi.txt @@ -0,0 +1,148 @@ +Mediatek HDMI Encoder +===================== + +The Mediatek HDMI encoder can generate HDMI 1.4a or MHL 2.0 signals from +its parallel input. + +Required properties: +- compatible: Should be "mediatek,-hdmi". +- reg: Physical base address and length of the controller's registers +- interrupts: The interrupt signal from the function block. +- clocks: device clocks + See Documentation/devicetree/bindings/clock/clock-bindings.txt for details. +- clock-names: must contain "pixel", "pll", "bclk", and "spdif". +- phys: phandle link to the HDMI PHY node. + See Documentation/devicetree/bindings/phy/phy-bindings.txt for details. +- phy-names: must contain "hdmi" +- mediatek,syscon-hdmi: phandle link and register offset to the system + configuration registers. For mt8173 this must be offset 0x900 into the + MMSYS_CONFIG region: <&mmsys 0x900>. +- ports: A node containing input and output port nodes with endpoint + definitions as documented in Documentation/devicetree/bindings/graph.txt. +- port@0: The input port in the ports node should be connected to a DPI output + port. +- port@1: The output port in the ports node should be connected to the input + port of a connector node that contains a ddc-i2c-bus property, or to the + input port of an attached bridge chip, such as a SlimPort transmitter. + +HDMI CEC +======== + +The HDMI CEC controller handles hotplug detection and CEC communication. + +Required properties: +- compatible: Should be "mediatek,-cec" +- reg: Physical base address and length of the controller's registers +- interrupts: The interrupt signal from the function block. +- clocks: device clock + +HDMI DDC +======== + +The HDMI DDC i2c controller is used to interface with the HDMI DDC pins. +The Mediatek's I2C controller is used to interface with I2C devices. + +Required properties: +- compatible: Should be "mediatek,-hdmi-ddc" +- reg: Physical base address and length of the controller's registers +- clocks: device clock +- clock-names: Should be "ddc-i2c". + +HDMI PHY +======== + +The HDMI PHY serializes the HDMI encoder's three channel 10-bit parallel +output and drives the HDMI pads. + +Required properties: +- compatible: "mediatek,-hdmi-phy" +- reg: Physical base address and length of the module's registers +- clocks: PLL reference clock +- clock-names: must contain "pll_ref" +- clock-output-names: must be "hdmitx_dig_cts" on mt8173 +- #phy-cells: must be <0> +- #clock-cells: must be <0> + +Optional properties: +- mediatek,ibias: TX DRV bias current for <1.65Gbps, defaults to 0xa +- mediatek,ibias_up: TX DRV bias current for >1.65Gbps, defaults to 0x1c + +Example: + +cec: cec@10013000 { + compatible = "mediatek,mt8173-cec"; + reg = <0 0x10013000 0 0xbc>; + interrupts = ; + clocks = <&infracfg CLK_INFRA_CEC>; +}; + +hdmi_phy: hdmi-phy@10209100 { + compatible = "mediatek,mt8173-hdmi-phy"; + reg = <0 0x10209100 0 0x24>; + clocks = <&apmixedsys CLK_APMIXED_HDMI_REF>; + clock-names = "pll_ref"; + clock-output-names = "hdmitx_dig_cts"; + mediatek,ibias = <0xa>; + mediatek,ibias_up = <0x1c>; + #clock-cells = <0>; + #phy-cells = <0>; +}; + +hdmi_ddc0: i2c@11012000 { + compatible = "mediatek,mt8173-hdmi-ddc"; + reg = <0 0x11012000 0 0x1c>; + interrupts = ; + clocks = <&pericfg CLK_PERI_I2C5>; + clock-names = "ddc-i2c"; +}; + +hdmi0: hdmi@14025000 { + compatible = "mediatek,mt8173-hdmi"; + reg = <0 0x14025000 0 0x400>; + interrupts = ; + clocks = <&mmsys CLK_MM_HDMI_PIXEL>, + <&mmsys CLK_MM_HDMI_PLLCK>, + <&mmsys CLK_MM_HDMI_AUDIO>, + <&mmsys CLK_MM_HDMI_SPDIF>; + clock-names = "pixel", "pll", "bclk", "spdif"; + pinctrl-names = "default"; + pinctrl-0 = <&hdmi_pin>; + phys = <&hdmi_phy>; + phy-names = "hdmi"; + mediatek,syscon-hdmi = <&mmsys 0x900>; + assigned-clocks = <&topckgen CLK_TOP_HDMI_SEL>; + assigned-clock-parents = <&hdmi_phy>; + + ports { + #address-cells = <1>; + #size-cells = <0>; + + port@0 { + reg = <0>; + + hdmi0_in: endpoint { + remote-endpoint = <&dpi0_out>; + }; + }; + + port@1 { + reg = <1>; + + hdmi0_out: endpoint { + remote-endpoint = <&hdmi_con_in>; + }; + }; + }; +}; + +connector { + compatible = "hdmi-connector"; + type = "a"; + ddc-i2c-bus = <&hdmiddc0>; + + port { + hdmi_con_in: endpoint { + remote-endpoint = <&hdmi0_out>; + }; + }; +}; diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst new file mode 100644 index 000000000000..4f7176576feb --- /dev/null +++ b/Documentation/gpu/drm-internals.rst @@ -0,0 +1,378 @@ +============= +DRM Internals +============= + +This chapter documents DRM internals relevant to driver authors and +developers working to add support for the latest features to existing +drivers. + +First, we go over some typical driver initialization requirements, like +setting up command buffers, creating an initial output configuration, +and initializing core services. Subsequent sections cover core internals +in more detail, providing implementation notes and examples. + +The DRM layer provides several services to graphics drivers, many of +them driven by the application interfaces it provides through libdrm, +the library that wraps most of the DRM ioctls. These include vblank +event handling, memory management, output management, framebuffer +management, command submission & fencing, suspend/resume support, and +DMA services. + +Driver Initialization +===================== + +At the core of every DRM driver is a :c:type:`struct drm_driver +` structure. Drivers typically statically initialize +a drm_driver structure, and then pass it to +:c:func:`drm_dev_alloc()` to allocate a device instance. After the +device instance is fully initialized it can be registered (which makes +it accessible from userspace) using :c:func:`drm_dev_register()`. + +The :c:type:`struct drm_driver ` structure +contains static information that describes the driver and features it +supports, and pointers to methods that the DRM core will call to +implement the DRM API. We will first go through the :c:type:`struct +drm_driver ` static information fields, and will +then describe individual operations in details as they get used in later +sections. + +Driver Information +------------------ + +Driver Features +~~~~~~~~~~~~~~~ + +Drivers inform the DRM core about their requirements and supported +features by setting appropriate flags in the driver_features field. +Since those flags influence the DRM core behaviour since registration +time, most of them must be set to registering the :c:type:`struct +drm_driver ` instance. + +u32 driver_features; + +DRIVER_USE_AGP + Driver uses AGP interface, the DRM core will manage AGP resources. + +DRIVER_REQUIRE_AGP + Driver needs AGP interface to function. AGP initialization failure + will become a fatal error. + +DRIVER_PCI_DMA + Driver is capable of PCI DMA, mapping of PCI DMA buffers to + userspace will be enabled. Deprecated. + +DRIVER_SG + Driver can perform scatter/gather DMA, allocation and mapping of + scatter/gather buffers will be enabled. Deprecated. + +DRIVER_HAVE_DMA + Driver supports DMA, the userspace DMA API will be supported. + Deprecated. + +DRIVER_HAVE_IRQ; DRIVER_IRQ_SHARED + DRIVER_HAVE_IRQ indicates whether the driver has an IRQ handler + managed by the DRM Core. The core will support simple IRQ handler + installation when the flag is set. The installation process is + described in ?. + + DRIVER_IRQ_SHARED indicates whether the device & handler support + shared IRQs (note that this is required of PCI drivers). + +DRIVER_GEM + Driver use the GEM memory manager. + +DRIVER_MODESET + Driver supports mode setting interfaces (KMS). + +DRIVER_PRIME + Driver implements DRM PRIME buffer sharing. + +DRIVER_RENDER + Driver supports dedicated render nodes. + +DRIVER_ATOMIC + Driver supports atomic properties. In this case the driver must + implement appropriate obj->atomic_get_property() vfuncs for any + modeset objects with driver specific properties. + +Major, Minor and Patchlevel +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +int major; int minor; int patchlevel; +The DRM core identifies driver versions by a major, minor and patch +level triplet. The information is printed to the kernel log at +initialization time and passed to userspace through the +DRM_IOCTL_VERSION ioctl. + +The major and minor numbers are also used to verify the requested driver +API version passed to DRM_IOCTL_SET_VERSION. When the driver API +changes between minor versions, applications can call +DRM_IOCTL_SET_VERSION to select a specific version of the API. If the +requested major isn't equal to the driver major, or the requested minor +is larger than the driver minor, the DRM_IOCTL_SET_VERSION call will +return an error. Otherwise the driver's set_version() method will be +called with the requested version. + +Name, Description and Date +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +char \*name; char \*desc; char \*date; +The driver name is printed to the kernel log at initialization time, +used for IRQ registration and passed to userspace through +DRM_IOCTL_VERSION. + +The driver description is a purely informative string passed to +userspace through the DRM_IOCTL_VERSION ioctl and otherwise unused by +the kernel. + +The driver date, formatted as YYYYMMDD, is meant to identify the date of +the latest modification to the driver. However, as most drivers fail to +update it, its value is mostly useless. The DRM core prints it to the +kernel log at initialization time and passes it to userspace through the +DRM_IOCTL_VERSION ioctl. + +Device Instance and Driver Handling +----------------------------------- + +.. kernel-doc:: drivers/gpu/drm/drm_drv.c + :doc: driver instance overview + +.. kernel-doc:: drivers/gpu/drm/drm_drv.c + :export: + +Driver Load +----------- + +IRQ Registration +~~~~~~~~~~~~~~~~ + +The DRM core tries to facilitate IRQ handler registration and +unregistration by providing :c:func:`drm_irq_install()` and +:c:func:`drm_irq_uninstall()` functions. Those functions only +support a single interrupt per device, devices that use more than one +IRQs need to be handled manually. + +Managed IRQ Registration +'''''''''''''''''''''''' + +:c:func:`drm_irq_install()` starts by calling the irq_preinstall +driver operation. The operation is optional and must make sure that the +interrupt will not get fired by clearing all pending interrupt flags or +disabling the interrupt. + +The passed-in IRQ will then be requested by a call to +:c:func:`request_irq()`. If the DRIVER_IRQ_SHARED driver feature +flag is set, a shared (IRQF_SHARED) IRQ handler will be requested. + +The IRQ handler function must be provided as the mandatory irq_handler +driver operation. It will get passed directly to +:c:func:`request_irq()` and thus has the same prototype as all IRQ +handlers. It will get called with a pointer to the DRM device as the +second argument. + +Finally the function calls the optional irq_postinstall driver +operation. The operation usually enables interrupts (excluding the +vblank interrupt, which is enabled separately), but drivers may choose +to enable/disable interrupts at a different time. + +:c:func:`drm_irq_uninstall()` is similarly used to uninstall an +IRQ handler. It starts by waking up all processes waiting on a vblank +interrupt to make sure they don't hang, and then calls the optional +irq_uninstall driver operation. The operation must disable all hardware +interrupts. Finally the function frees the IRQ by calling +:c:func:`free_irq()`. + +Manual IRQ Registration +''''''''''''''''''''''' + +Drivers that require multiple interrupt handlers can't use the managed +IRQ registration functions. In that case IRQs must be registered and +unregistered manually (usually with the :c:func:`request_irq()` and +:c:func:`free_irq()` functions, or their devm_\* equivalent). + +When manually registering IRQs, drivers must not set the +DRIVER_HAVE_IRQ driver feature flag, and must not provide the +irq_handler driver operation. They must set the :c:type:`struct +drm_device ` irq_enabled field to 1 upon +registration of the IRQs, and clear it to 0 after unregistering the +IRQs. + +Memory Manager Initialization +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Every DRM driver requires a memory manager which must be initialized at +load time. DRM currently contains two memory managers, the Translation +Table Manager (TTM) and the Graphics Execution Manager (GEM). This +document describes the use of the GEM memory manager only. See ? for +details. + +Miscellaneous Device Configuration +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Another task that may be necessary for PCI devices during configuration +is mapping the video BIOS. On many devices, the VBIOS describes device +configuration, LCD panel timings (if any), and contains flags indicating +device state. Mapping the BIOS can be done using the pci_map_rom() +call, a convenience function that takes care of mapping the actual ROM, +whether it has been shadowed into memory (typically at address 0xc0000) +or exists on the PCI device in the ROM BAR. Note that after the ROM has +been mapped and any necessary information has been extracted, it should +be unmapped; on many devices, the ROM address decoder is shared with +other BARs, so leaving it mapped could cause undesired behaviour like +hangs or memory corruption. + +Bus-specific Device Registration and PCI Support +------------------------------------------------ + +A number of functions are provided to help with device registration. The +functions deal with PCI and platform devices respectively and are only +provided for historical reasons. These are all deprecated and shouldn't +be used in new drivers. Besides that there's a few helpers for pci +drivers. + +.. kernel-doc:: drivers/gpu/drm/drm_pci.c + :export: + +.. kernel-doc:: drivers/gpu/drm/drm_platform.c + :export: + +Open/Close, File Operations and IOCTLs +====================================== + +Open and Close +-------------- + +int (\*firstopen) (struct drm_device \*); void (\*lastclose) (struct +drm_device \*); int (\*open) (struct drm_device \*, struct drm_file +\*); void (\*preclose) (struct drm_device \*, struct drm_file \*); +void (\*postclose) (struct drm_device \*, struct drm_file \*); + Open and close handlers. None of those methods are mandatory. + +The firstopen method is called by the DRM core for legacy UMS (User Mode +Setting) drivers only when an application opens a device that has no +other opened file handle. UMS drivers can implement it to acquire device +resources. KMS drivers can't use the method and must acquire resources +in the load method instead. + +Similarly the lastclose method is called when the last application +holding a file handle opened on the device closes it, for both UMS and +KMS drivers. Additionally, the method is also called at module unload +time or, for hot-pluggable devices, when the device is unplugged. The +firstopen and lastclose calls can thus be unbalanced. + +The open method is called every time the device is opened by an +application. Drivers can allocate per-file private data in this method +and store them in the struct :c:type:`struct drm_file +` driver_priv field. Note that the open method is +called before firstopen. + +The close operation is split into preclose and postclose methods. +Drivers must stop and cleanup all per-file operations in the preclose +method. For instance pending vertical blanking and page flip events must +be cancelled. No per-file operation is allowed on the file handle after +returning from the preclose method. + +Finally the postclose method is called as the last step of the close +operation, right before calling the lastclose method if no other open +file handle exists for the device. Drivers that have allocated per-file +private data in the open method should free it here. + +The lastclose method should restore CRTC and plane properties to default +value, so that a subsequent open of the device will not inherit state +from the previous user. It can also be used to execute delayed power +switching state changes, e.g. in conjunction with the vga_switcheroo +infrastructure (see ?). Beyond that KMS drivers should not do any +further cleanup. Only legacy UMS drivers might need to clean up device +state so that the vga console or an independent fbdev driver could take +over. + +File Operations +--------------- + +.. kernel-doc:: drivers/gpu/drm/drm_fops.c + :doc: file operations + +.. kernel-doc:: drivers/gpu/drm/drm_fops.c + :export: + +IOCTLs +------ + +struct drm_ioctl_desc \*ioctls; int num_ioctls; + Driver-specific ioctls descriptors table. + +Driver-specific ioctls numbers start at DRM_COMMAND_BASE. The ioctls +descriptors table is indexed by the ioctl number offset from the base +value. Drivers can use the DRM_IOCTL_DEF_DRV() macro to initialize +the table entries. + +:: + + DRM_IOCTL_DEF_DRV(ioctl, func, flags) + +``ioctl`` is the ioctl name. Drivers must define the DRM_##ioctl and +DRM_IOCTL_##ioctl macros to the ioctl number offset from +DRM_COMMAND_BASE and the ioctl number respectively. The first macro is +private to the device while the second must be exposed to userspace in a +public header. + +``func`` is a pointer to the ioctl handler function compatible with the +``drm_ioctl_t`` type. + +:: + + typedef int drm_ioctl_t(struct drm_device *dev, void *data, + struct drm_file *file_priv); + +``flags`` is a bitmask combination of the following values. It restricts +how the ioctl is allowed to be called. + +- DRM_AUTH - Only authenticated callers allowed + +- DRM_MASTER - The ioctl can only be called on the master file handle + +- DRM_ROOT_ONLY - Only callers with the SYSADMIN capability allowed + +- DRM_CONTROL_ALLOW - The ioctl can only be called on a control + device + +- DRM_UNLOCKED - The ioctl handler will be called without locking the + DRM global mutex. This is the enforced default for kms drivers (i.e. + using the DRIVER_MODESET flag) and hence shouldn't be used any more + for new drivers. + +.. kernel-doc:: drivers/gpu/drm/drm_ioctl.c + :export: + +Legacy Support Code +=================== + +The section very briefly covers some of the old legacy support code +which is only used by old DRM drivers which have done a so-called +shadow-attach to the underlying device instead of registering as a real +driver. This also includes some of the old generic buffer management and +command submission code. Do not use any of this in new and modern +drivers. + +Legacy Suspend/Resume +--------------------- + +The DRM core provides some suspend/resume code, but drivers wanting full +suspend/resume support should provide save() and restore() functions. +These are called at suspend, hibernate, or resume time, and should +perform any state save or restore required by your device across suspend +or hibernate states. + +int (\*suspend) (struct drm_device \*, pm_message_t state); int +(\*resume) (struct drm_device \*); +Those are legacy suspend and resume methods which *only* work with the +legacy shadow-attach driver registration functions. New driver should +use the power management interface provided by their bus type (usually +through the :c:type:`struct device_driver ` +dev_pm_ops) and set these methods to NULL. + +Legacy DMA Services +------------------- + +This should cover how DMA mapping etc. is supported by the core. These +functions are deprecated and should not be used. diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst new file mode 100644 index 000000000000..0b302fedf1af --- /dev/null +++ b/Documentation/gpu/drm-kms-helpers.rst @@ -0,0 +1,260 @@ +============================= +Mode Setting Helper Functions +============================= + +The plane, CRTC, encoder and connector functions provided by the drivers +implement the DRM API. They're called by the DRM core and ioctl handlers +to handle device state changes and configuration request. As +implementing those functions often requires logic not specific to +drivers, mid-layer helper functions are available to avoid duplicating +boilerplate code. + +The DRM core contains one mid-layer implementation. The mid-layer +provides implementations of several plane, CRTC, encoder and connector +functions (called from the top of the mid-layer) that pre-process +requests and call lower-level functions provided by the driver (at the +bottom of the mid-layer). For instance, the +:c:func:`drm_crtc_helper_set_config()` function can be used to +fill the :c:type:`struct drm_crtc_funcs ` +set_config field. When called, it will split the set_config operation +in smaller, simpler operations and call the driver to handle them. + +To use the mid-layer, drivers call +:c:func:`drm_crtc_helper_add()`, +:c:func:`drm_encoder_helper_add()` and +:c:func:`drm_connector_helper_add()` functions to install their +mid-layer bottom operations handlers, and fill the :c:type:`struct +drm_crtc_funcs `, :c:type:`struct +drm_encoder_funcs ` and :c:type:`struct +drm_connector_funcs ` structures with +pointers to the mid-layer top API functions. Installing the mid-layer +bottom operation handlers is best done right after registering the +corresponding KMS object. + +The mid-layer is not split between CRTC, encoder and connector +operations. To use it, a driver must provide bottom functions for all of +the three KMS entities. + +Atomic Modeset Helper Functions Reference +========================================= + +Overview +-------- + +.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c + :doc: overview + +Implementing Asynchronous Atomic Commit +--------------------------------------- + +.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c + :doc: implementing nonblocking commit + +Atomic State Reset and Initialization +------------------------------------- + +.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c + :doc: atomic state reset and initialization + +.. kernel-doc:: include/drm/drm_atomic_helper.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c + :export: + +Modeset Helper Reference for Common Vtables +=========================================== + +.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h + :internal: + +.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h + :doc: overview + +Legacy CRTC/Modeset Helper Functions Reference +============================================== + +.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c + :export: + +.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c + :doc: overview + +Output Probing Helper Functions Reference +========================================= + +.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c + :doc: output probing helper overview + +.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c + :export: + +fbdev Helper Functions Reference +================================ + +.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c + :doc: fbdev helpers + +.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c + :export: + +.. kernel-doc:: include/drm/drm_fb_helper.h + :internal: + +Framebuffer CMA Helper Functions Reference +========================================== + +.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c + :doc: framebuffer cma helper functions + +.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c + :export: + +Display Port Helper Functions Reference +======================================= + +.. kernel-doc:: drivers/gpu/drm/drm_dp_helper.c + :doc: dp helpers + +.. kernel-doc:: include/drm/drm_dp_helper.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_dp_helper.c + :export: + +Display Port Dual Mode Adaptor Helper Functions Reference +========================================================= + +.. kernel-doc:: drivers/gpu/drm/drm_dp_dual_mode_helper.c + :doc: dp dual mode helpers + +.. kernel-doc:: include/drm/drm_dp_dual_mode_helper.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_dp_dual_mode_helper.c + :export: + +Display Port MST Helper Functions Reference +=========================================== + +.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c + :doc: dp mst helper + +.. kernel-doc:: include/drm/drm_dp_mst_helper.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c + :export: + +MIPI DSI Helper Functions Reference +=================================== + +.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c + :doc: dsi helpers + +.. kernel-doc:: include/drm/drm_mipi_dsi.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c + :export: + +EDID Helper Functions Reference +=============================== + +.. kernel-doc:: drivers/gpu/drm/drm_edid.c + :export: + +Rectangle Utilities Reference +============================= + +.. kernel-doc:: include/drm/drm_rect.h + :doc: rect utils + +.. kernel-doc:: include/drm/drm_rect.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_rect.c + :export: + +Flip-work Helper Reference +========================== + +.. kernel-doc:: include/drm/drm_flip_work.h + :doc: flip utils + +.. kernel-doc:: include/drm/drm_flip_work.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_flip_work.c + :export: + +HDMI Infoframes Helper Reference +================================ + +Strictly speaking this is not a DRM helper library but generally useable +by any driver interfacing with HDMI outputs like v4l or alsa drivers. +But it nicely fits into the overall topic of mode setting helper +libraries and hence is also included here. + +.. kernel-doc:: include/linux/hdmi.h + :internal: + +.. kernel-doc:: drivers/video/hdmi.c + :export: + +Plane Helper Reference +====================== + +.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c + :export: + +.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c + :doc: overview + +Tile group +---------- + +.. kernel-doc:: drivers/gpu/drm/drm_crtc.c + :doc: Tile group + +Bridges +======= + +Overview +-------- + +.. kernel-doc:: drivers/gpu/drm/drm_bridge.c + :doc: overview + +Default bridge callback sequence +-------------------------------- + +.. kernel-doc:: drivers/gpu/drm/drm_bridge.c + :doc: bridge callbacks + +.. kernel-doc:: drivers/gpu/drm/drm_bridge.c + :export: + +Panel Helper Reference +====================== + +.. kernel-doc:: include/drm/drm_panel.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_panel.c + :export: + +.. kernel-doc:: drivers/gpu/drm/drm_panel.c + :doc: drm panel + +Simple KMS Helper Reference +=========================== + +.. kernel-doc:: include/drm/drm_simple_kms_helper.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c + :export: + +.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c + :doc: overview diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst new file mode 100644 index 000000000000..0e1c80436c1d --- /dev/null +++ b/Documentation/gpu/drm-kms.rst @@ -0,0 +1,656 @@ +========================= +Kernel Mode Setting (KMS) +========================= + +Mode Setting +============ + +Drivers must initialize the mode setting core by calling +:c:func:`drm_mode_config_init()` on the DRM device. The function +initializes the :c:type:`struct drm_device ` +mode_config field and never fails. Once done, mode configuration must +be setup by initializing the following fields. + +- int min_width, min_height; int max_width, max_height; + Minimum and maximum width and height of the frame buffers in pixel + units. + +- struct drm_mode_config_funcs \*funcs; + Mode setting functions. + +Display Modes Function Reference +-------------------------------- + +.. kernel-doc:: include/drm/drm_modes.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_modes.c + :export: + +Atomic Mode Setting Function Reference +-------------------------------------- + +.. kernel-doc:: drivers/gpu/drm/drm_atomic.c + :export: + +.. kernel-doc:: drivers/gpu/drm/drm_atomic.c + :internal: + +Frame Buffer Abstraction +------------------------ + +Frame buffers are abstract memory objects that provide a source of +pixels to scanout to a CRTC. Applications explicitly request the +creation of frame buffers through the DRM_IOCTL_MODE_ADDFB(2) ioctls +and receive an opaque handle that can be passed to the KMS CRTC control, +plane configuration and page flip functions. + +Frame buffers rely on the underneath memory manager for low-level memory +operations. When creating a frame buffer applications pass a memory +handle (or a list of memory handles for multi-planar formats) through +the ``drm_mode_fb_cmd2`` argument. For drivers using GEM as their +userspace buffer management interface this would be a GEM handle. +Drivers are however free to use their own backing storage object +handles, e.g. vmwgfx directly exposes special TTM handles to userspace +and so expects TTM handles in the create ioctl and not GEM handles. + +The lifetime of a drm framebuffer is controlled with a reference count, +drivers can grab additional references with +:c:func:`drm_framebuffer_reference()`and drop them again with +:c:func:`drm_framebuffer_unreference()`. For driver-private +framebuffers for which the last reference is never dropped (e.g. for the +fbdev framebuffer when the struct :c:type:`struct drm_framebuffer +` is embedded into the fbdev helper struct) +drivers can manually clean up a framebuffer at module unload time with +:c:func:`drm_framebuffer_unregister_private()`. + +DRM Format Handling +------------------- + +.. kernel-doc:: include/drm/drm_fourcc.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_fourcc.c + :export: + +Dumb Buffer Objects +------------------- + +The KMS API doesn't standardize backing storage object creation and +leaves it to driver-specific ioctls. Furthermore actually creating a +buffer object even for GEM-based drivers is done through a +driver-specific ioctl - GEM only has a common userspace interface for +sharing and destroying objects. While not an issue for full-fledged +graphics stacks that include device-specific userspace components (in +libdrm for instance), this limit makes DRM-based early boot graphics +unnecessarily complex. + +Dumb objects partly alleviate the problem by providing a standard API to +create dumb buffers suitable for scanout, which can then be used to +create KMS frame buffers. + +To support dumb objects drivers must implement the dumb_create, +dumb_destroy and dumb_map_offset operations. + +- int (\*dumb_create)(struct drm_file \*file_priv, struct + drm_device \*dev, struct drm_mode_create_dumb \*args); + The dumb_create operation creates a driver object (GEM or TTM + handle) suitable for scanout based on the width, height and depth + from the struct :c:type:`struct drm_mode_create_dumb + ` argument. It fills the argument's + handle, pitch and size fields with a handle for the newly created + object and its line pitch and size in bytes. + +- int (\*dumb_destroy)(struct drm_file \*file_priv, struct + drm_device \*dev, uint32_t handle); + The dumb_destroy operation destroys a dumb object created by + dumb_create. + +- int (\*dumb_map_offset)(struct drm_file \*file_priv, struct + drm_device \*dev, uint32_t handle, uint64_t \*offset); + The dumb_map_offset operation associates an mmap fake offset with + the object given by the handle and returns it. Drivers must use the + :c:func:`drm_gem_create_mmap_offset()` function to associate + the fake offset as described in ?. + +Note that dumb objects may not be used for gpu acceleration, as has been +attempted on some ARM embedded platforms. Such drivers really must have +a hardware-specific ioctl to allocate suitable buffer objects. + +Output Polling +-------------- + +void (\*output_poll_changed)(struct drm_device \*dev); +This operation notifies the driver that the status of one or more +connectors has changed. Drivers that use the fb helper can just call the +:c:func:`drm_fb_helper_hotplug_event()` function to handle this +operation. + +KMS Initialization and Cleanup +============================== + +A KMS device is abstracted and exposed as a set of planes, CRTCs, +encoders and connectors. KMS drivers must thus create and initialize all +those objects at load time after initializing mode setting. + +CRTCs (:c:type:`struct drm_crtc `) +-------------------------------------------- + +A CRTC is an abstraction representing a part of the chip that contains a +pointer to a scanout buffer. Therefore, the number of CRTCs available +determines how many independent scanout buffers can be active at any +given time. The CRTC structure contains several fields to support this: +a pointer to some video memory (abstracted as a frame buffer object), a +display mode, and an (x, y) offset into the video memory to support +panning or configurations where one piece of video memory spans multiple +CRTCs. + +CRTC Initialization +~~~~~~~~~~~~~~~~~~~ + +A KMS device must create and register at least one struct +:c:type:`struct drm_crtc ` instance. The instance is +allocated and zeroed by the driver, possibly as part of a larger +structure, and registered with a call to :c:func:`drm_crtc_init()` +with a pointer to CRTC functions. + +Planes (:c:type:`struct drm_plane `) +----------------------------------------------- + +A plane represents an image source that can be blended with or overlayed +on top of a CRTC during the scanout process. Planes are associated with +a frame buffer to crop a portion of the image memory (source) and +optionally scale it to a destination size. The result is then blended +with or overlayed on top of a CRTC. + +The DRM core recognizes three types of planes: + +- DRM_PLANE_TYPE_PRIMARY represents a "main" plane for a CRTC. + Primary planes are the planes operated upon by CRTC modesetting and + flipping operations described in the page_flip hook in + :c:type:`struct drm_crtc_funcs `. +- DRM_PLANE_TYPE_CURSOR represents a "cursor" plane for a CRTC. + Cursor planes are the planes operated upon by the + DRM_IOCTL_MODE_CURSOR and DRM_IOCTL_MODE_CURSOR2 ioctls. +- DRM_PLANE_TYPE_OVERLAY represents all non-primary, non-cursor + planes. Some drivers refer to these types of planes as "sprites" + internally. + +For compatibility with legacy userspace, only overlay planes are made +available to userspace by default. Userspace clients may set the +DRM_CLIENT_CAP_UNIVERSAL_PLANES client capability bit to indicate +that they wish to receive a universal plane list containing all plane +types. + +Plane Initialization +~~~~~~~~~~~~~~~~~~~~ + +To create a plane, a KMS drivers allocates and zeroes an instances of +:c:type:`struct drm_plane ` (possibly as part of a +larger structure) and registers it with a call to +:c:func:`drm_universal_plane_init()`. The function takes a +bitmask of the CRTCs that can be associated with the plane, a pointer to +the plane functions, a list of format supported formats, and the type of +plane (primary, cursor, or overlay) being initialized. + +Cursor and overlay planes are optional. All drivers should provide one +primary plane per CRTC (although this requirement may change in the +future); drivers that do not wish to provide special handling for +primary planes may make use of the helper functions described in ? to +create and register a primary plane with standard capabilities. + +Encoders (:c:type:`struct drm_encoder `) +----------------------------------------------------- + +An encoder takes pixel data from a CRTC and converts it to a format +suitable for any attached connectors. On some devices, it may be +possible to have a CRTC send data to more than one encoder. In that +case, both encoders would receive data from the same scanout buffer, +resulting in a "cloned" display configuration across the connectors +attached to each encoder. + +Encoder Initialization +~~~~~~~~~~~~~~~~~~~~~~ + +As for CRTCs, a KMS driver must create, initialize and register at least +one :c:type:`struct drm_encoder ` instance. The +instance is allocated and zeroed by the driver, possibly as part of a +larger structure. + +Drivers must initialize the :c:type:`struct drm_encoder +` possible_crtcs and possible_clones fields before +registering the encoder. Both fields are bitmasks of respectively the +CRTCs that the encoder can be connected to, and sibling encoders +candidate for cloning. + +After being initialized, the encoder must be registered with a call to +:c:func:`drm_encoder_init()`. The function takes a pointer to the +encoder functions and an encoder type. Supported types are + +- DRM_MODE_ENCODER_DAC for VGA and analog on DVI-I/DVI-A +- DRM_MODE_ENCODER_TMDS for DVI, HDMI and (embedded) DisplayPort +- DRM_MODE_ENCODER_LVDS for display panels +- DRM_MODE_ENCODER_TVDAC for TV output (Composite, S-Video, + Component, SCART) +- DRM_MODE_ENCODER_VIRTUAL for virtual machine displays + +Encoders must be attached to a CRTC to be used. DRM drivers leave +encoders unattached at initialization time. Applications (or the fbdev +compatibility layer when implemented) are responsible for attaching the +encoders they want to use to a CRTC. + +Connectors (:c:type:`struct drm_connector `) +----------------------------------------------------------- + +A connector is the final destination for pixel data on a device, and +usually connects directly to an external display device like a monitor +or laptop panel. A connector can only be attached to one encoder at a +time. The connector is also the structure where information about the +attached display is kept, so it contains fields for display data, EDID +data, DPMS & connection status, and information about modes supported on +the attached displays. + +Connector Initialization +~~~~~~~~~~~~~~~~~~~~~~~~ + +Finally a KMS driver must create, initialize, register and attach at +least one :c:type:`struct drm_connector ` +instance. The instance is created as other KMS objects and initialized +by setting the following fields. + +interlace_allowed + Whether the connector can handle interlaced modes. + +doublescan_allowed + Whether the connector can handle doublescan. + +display_info + Display information is filled from EDID information when a display + is detected. For non hot-pluggable displays such as flat panels in + embedded systems, the driver should initialize the + display_info.width_mm and display_info.height_mm fields with the + physical size of the display. + +polled + Connector polling mode, a combination of + + DRM_CONNECTOR_POLL_HPD + The connector generates hotplug events and doesn't need to be + periodically polled. The CONNECT and DISCONNECT flags must not + be set together with the HPD flag. + + DRM_CONNECTOR_POLL_CONNECT + Periodically poll the connector for connection. + + DRM_CONNECTOR_POLL_DISCONNECT + Periodically poll the connector for disconnection. + + Set to 0 for connectors that don't support connection status + discovery. + +The connector is then registered with a call to +:c:func:`drm_connector_init()` with a pointer to the connector +functions and a connector type, and exposed through sysfs with a call to +:c:func:`drm_connector_register()`. + +Supported connector types are + +- DRM_MODE_CONNECTOR_VGA +- DRM_MODE_CONNECTOR_DVII +- DRM_MODE_CONNECTOR_DVID +- DRM_MODE_CONNECTOR_DVIA +- DRM_MODE_CONNECTOR_Composite +- DRM_MODE_CONNECTOR_SVIDEO +- DRM_MODE_CONNECTOR_LVDS +- DRM_MODE_CONNECTOR_Component +- DRM_MODE_CONNECTOR_9PinDIN +- DRM_MODE_CONNECTOR_DisplayPort +- DRM_MODE_CONNECTOR_HDMIA +- DRM_MODE_CONNECTOR_HDMIB +- DRM_MODE_CONNECTOR_TV +- DRM_MODE_CONNECTOR_eDP +- DRM_MODE_CONNECTOR_VIRTUAL + +Connectors must be attached to an encoder to be used. For devices that +map connectors to encoders 1:1, the connector should be attached at +initialization time with a call to +:c:func:`drm_mode_connector_attach_encoder()`. The driver must +also set the :c:type:`struct drm_connector ` +encoder field to point to the attached encoder. + +Finally, drivers must initialize the connectors state change detection +with a call to :c:func:`drm_kms_helper_poll_init()`. If at least +one connector is pollable but can't generate hotplug interrupts +(indicated by the DRM_CONNECTOR_POLL_CONNECT and +DRM_CONNECTOR_POLL_DISCONNECT connector flags), a delayed work will +automatically be queued to periodically poll for changes. Connectors +that can generate hotplug interrupts must be marked with the +DRM_CONNECTOR_POLL_HPD flag instead, and their interrupt handler must +call :c:func:`drm_helper_hpd_irq_event()`. The function will +queue a delayed work to check the state of all connectors, but no +periodic polling will be done. + +Connector Operations +~~~~~~~~~~~~~~~~~~~~ + + **Note** + + Unless otherwise state, all operations are mandatory. + +DPMS +'''' + +void (\*dpms)(struct drm_connector \*connector, int mode); +The DPMS operation sets the power state of a connector. The mode +argument is one of + +- DRM_MODE_DPMS_ON + +- DRM_MODE_DPMS_STANDBY + +- DRM_MODE_DPMS_SUSPEND + +- DRM_MODE_DPMS_OFF + +In all but DPMS_ON mode the encoder to which the connector is attached +should put the display in low-power mode by driving its signals +appropriately. If more than one connector is attached to the encoder +care should be taken not to change the power state of other displays as +a side effect. Low-power mode should be propagated to the encoders and +CRTCs when all related connectors are put in low-power mode. + +Modes +''''' + +int (\*fill_modes)(struct drm_connector \*connector, uint32_t +max_width, uint32_t max_height); +Fill the mode list with all supported modes for the connector. If the +``max_width`` and ``max_height`` arguments are non-zero, the +implementation must ignore all modes wider than ``max_width`` or higher +than ``max_height``. + +The connector must also fill in this operation its display_info +width_mm and height_mm fields with the connected display physical size +in millimeters. The fields should be set to 0 if the value isn't known +or is not applicable (for instance for projector devices). + +Connection Status +''''''''''''''''' + +The connection status is updated through polling or hotplug events when +supported (see ?). The status value is reported to userspace through +ioctls and must not be used inside the driver, as it only gets +initialized by a call to :c:func:`drm_mode_getconnector()` from +userspace. + +enum drm_connector_status (\*detect)(struct drm_connector +\*connector, bool force); +Check to see if anything is attached to the connector. The ``force`` +parameter is set to false whilst polling or to true when checking the +connector due to user request. ``force`` can be used by the driver to +avoid expensive, destructive operations during automated probing. + +Return connector_status_connected if something is connected to the +connector, connector_status_disconnected if nothing is connected and +connector_status_unknown if the connection state isn't known. + +Drivers should only return connector_status_connected if the +connection status has really been probed as connected. Connectors that +can't detect the connection status, or failed connection status probes, +should return connector_status_unknown. + +Cleanup +------- + +The DRM core manages its objects' lifetime. When an object is not needed +anymore the core calls its destroy function, which must clean up and +free every resource allocated for the object. Every +:c:func:`drm_\*_init()` call must be matched with a corresponding +:c:func:`drm_\*_cleanup()` call to cleanup CRTCs +(:c:func:`drm_crtc_cleanup()`), planes +(:c:func:`drm_plane_cleanup()`), encoders +(:c:func:`drm_encoder_cleanup()`) and connectors +(:c:func:`drm_connector_cleanup()`). Furthermore, connectors that +have been added to sysfs must be removed by a call to +:c:func:`drm_connector_unregister()` before calling +:c:func:`drm_connector_cleanup()`. + +Connectors state change detection must be cleanup up with a call to +:c:func:`drm_kms_helper_poll_fini()`. + +Output discovery and initialization example +------------------------------------------- + +:: + + void intel_crt_init(struct drm_device *dev) + { + struct drm_connector *connector; + struct intel_output *intel_output; + + intel_output = kzalloc(sizeof(struct intel_output), GFP_KERNEL); + if (!intel_output) + return; + + connector = &intel_output->base; + drm_connector_init(dev, &intel_output->base, + &intel_crt_connector_funcs, DRM_MODE_CONNECTOR_VGA); + + drm_encoder_init(dev, &intel_output->enc, &intel_crt_enc_funcs, + DRM_MODE_ENCODER_DAC); + + drm_mode_connector_attach_encoder(&intel_output->base, + &intel_output->enc); + + /* Set up the DDC bus. */ + intel_output->ddc_bus = intel_i2c_create(dev, GPIOA, "CRTDDC_A"); + if (!intel_output->ddc_bus) { + dev_printk(KERN_ERR, &dev->pdev->dev, "DDC bus registration " + "failed.\n"); + return; + } + + intel_output->type = INTEL_OUTPUT_ANALOG; + connector->interlace_allowed = 0; + connector->doublescan_allowed = 0; + + drm_encoder_helper_add(&intel_output->enc, &intel_crt_helper_funcs); + drm_connector_helper_add(connector, &intel_crt_connector_helper_funcs); + + drm_connector_register(connector); + } + +In the example above (taken from the i915 driver), a CRTC, connector and +encoder combination is created. A device-specific i2c bus is also +created for fetching EDID data and performing monitor detection. Once +the process is complete, the new connector is registered with sysfs to +make its properties available to applications. + +KMS API Functions +----------------- + +.. kernel-doc:: drivers/gpu/drm/drm_crtc.c + :export: + +KMS Data Structures +------------------- + +.. kernel-doc:: include/drm/drm_crtc.h + :internal: + +KMS Locking +----------- + +.. kernel-doc:: drivers/gpu/drm/drm_modeset_lock.c + :doc: kms locking + +.. kernel-doc:: include/drm/drm_modeset_lock.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_modeset_lock.c + :export: + +KMS Properties +============== + +Drivers may need to expose additional parameters to applications than +those described in the previous sections. KMS supports attaching +properties to CRTCs, connectors and planes and offers a userspace API to +list, get and set the property values. + +Properties are identified by a name that uniquely defines the property +purpose, and store an associated value. For all property types except +blob properties the value is a 64-bit unsigned integer. + +KMS differentiates between properties and property instances. Drivers +first create properties and then create and associate individual +instances of those properties to objects. A property can be instantiated +multiple times and associated with different objects. Values are stored +in property instances, and all other property information are stored in +the property and shared between all instances of the property. + +Every property is created with a type that influences how the KMS core +handles the property. Supported property types are + +DRM_MODE_PROP_RANGE + Range properties report their minimum and maximum admissible values. + The KMS core verifies that values set by application fit in that + range. + +DRM_MODE_PROP_ENUM + Enumerated properties take a numerical value that ranges from 0 to + the number of enumerated values defined by the property minus one, + and associate a free-formed string name to each value. Applications + can retrieve the list of defined value-name pairs and use the + numerical value to get and set property instance values. + +DRM_MODE_PROP_BITMASK + Bitmask properties are enumeration properties that additionally + restrict all enumerated values to the 0..63 range. Bitmask property + instance values combine one or more of the enumerated bits defined + by the property. + +DRM_MODE_PROP_BLOB + Blob properties store a binary blob without any format restriction. + The binary blobs are created as KMS standalone objects, and blob + property instance values store the ID of their associated blob + object. + + Blob properties are only used for the connector EDID property and + cannot be created by drivers. + +To create a property drivers call one of the following functions +depending on the property type. All property creation functions take +property flags and name, as well as type-specific arguments. + +- struct drm_property \*drm_property_create_range(struct + drm_device \*dev, int flags, const char \*name, uint64_t min, + uint64_t max); + Create a range property with the given minimum and maximum values. + +- struct drm_property \*drm_property_create_enum(struct drm_device + \*dev, int flags, const char \*name, const struct + drm_prop_enum_list \*props, int num_values); + Create an enumerated property. The ``props`` argument points to an + array of ``num_values`` value-name pairs. + +- struct drm_property \*drm_property_create_bitmask(struct + drm_device \*dev, int flags, const char \*name, const struct + drm_prop_enum_list \*props, int num_values); + Create a bitmask property. The ``props`` argument points to an array + of ``num_values`` value-name pairs. + +Properties can additionally be created as immutable, in which case they +will be read-only for applications but can be modified by the driver. To +create an immutable property drivers must set the +DRM_MODE_PROP_IMMUTABLE flag at property creation time. + +When no array of value-name pairs is readily available at property +creation time for enumerated or range properties, drivers can create the +property using the :c:func:`drm_property_create()` function and +manually add enumeration value-name pairs by calling the +:c:func:`drm_property_add_enum()` function. Care must be taken to +properly specify the property type through the ``flags`` argument. + +After creating properties drivers can attach property instances to CRTC, +connector and plane objects by calling the +:c:func:`drm_object_attach_property()`. The function takes a +pointer to the target object, a pointer to the previously created +property and an initial instance value. + +Existing KMS Properties +----------------------- + +The following table gives description of drm properties exposed by +various modules/drivers. + +.. csv-table:: + :header-rows: 1 + :file: kms-properties.csv + +Vertical Blanking +================= + +Vertical blanking plays a major role in graphics rendering. To achieve +tear-free display, users must synchronize page flips and/or rendering to +vertical blanking. The DRM API offers ioctls to perform page flips +synchronized to vertical blanking and wait for vertical blanking. + +The DRM core handles most of the vertical blanking management logic, +which involves filtering out spurious interrupts, keeping race-free +blanking counters, coping with counter wrap-around and resets and +keeping use counts. It relies on the driver to generate vertical +blanking interrupts and optionally provide a hardware vertical blanking +counter. Drivers must implement the following operations. + +- int (\*enable_vblank) (struct drm_device \*dev, int crtc); void + (\*disable_vblank) (struct drm_device \*dev, int crtc); + Enable or disable vertical blanking interrupts for the given CRTC. + +- u32 (\*get_vblank_counter) (struct drm_device \*dev, int crtc); + Retrieve the value of the vertical blanking counter for the given + CRTC. If the hardware maintains a vertical blanking counter its value + should be returned. Otherwise drivers can use the + :c:func:`drm_vblank_count()` helper function to handle this + operation. + +Drivers must initialize the vertical blanking handling core with a call +to :c:func:`drm_vblank_init()` in their load operation. + +Vertical blanking interrupts can be enabled by the DRM core or by +drivers themselves (for instance to handle page flipping operations). +The DRM core maintains a vertical blanking use count to ensure that the +interrupts are not disabled while a user still needs them. To increment +the use count, drivers call :c:func:`drm_vblank_get()`. Upon +return vertical blanking interrupts are guaranteed to be enabled. + +To decrement the use count drivers call +:c:func:`drm_vblank_put()`. Only when the use count drops to zero +will the DRM core disable the vertical blanking interrupts after a delay +by scheduling a timer. The delay is accessible through the +vblankoffdelay module parameter or the ``drm_vblank_offdelay`` global +variable and expressed in milliseconds. Its default value is 5000 ms. +Zero means never disable, and a negative value means disable +immediately. Drivers may override the behaviour by setting the +:c:type:`struct drm_device ` +vblank_disable_immediate flag, which when set causes vblank interrupts +to be disabled immediately regardless of the drm_vblank_offdelay +value. The flag should only be set if there's a properly working +hardware vblank counter present. + +When a vertical blanking interrupt occurs drivers only need to call the +:c:func:`drm_handle_vblank()` function to account for the +interrupt. + +Resources allocated by :c:func:`drm_vblank_init()` must be freed +with a call to :c:func:`drm_vblank_cleanup()` in the driver unload +operation handler. + +Vertical Blanking and Interrupt Handling Functions Reference +------------------------------------------------------------ + +.. kernel-doc:: drivers/gpu/drm/drm_irq.c + :export: + +.. kernel-doc:: include/drm/drmP.h + :functions: drm_crtc_vblank_waitqueue diff --git a/Documentation/gpu/drm-mm.rst b/Documentation/gpu/drm-mm.rst new file mode 100644 index 000000000000..59f9822fecd0 --- /dev/null +++ b/Documentation/gpu/drm-mm.rst @@ -0,0 +1,454 @@ +===================== +DRM Memory Management +===================== + +Modern Linux systems require large amount of graphics memory to store +frame buffers, textures, vertices and other graphics-related data. Given +the very dynamic nature of many of that data, managing graphics memory +efficiently is thus crucial for the graphics stack and plays a central +role in the DRM infrastructure. + +The DRM core includes two memory managers, namely Translation Table Maps +(TTM) and Graphics Execution Manager (GEM). TTM was the first DRM memory +manager to be developed and tried to be a one-size-fits-them all +solution. It provides a single userspace API to accommodate the need of +all hardware, supporting both Unified Memory Architecture (UMA) devices +and devices with dedicated video RAM (i.e. most discrete video cards). +This resulted in a large, complex piece of code that turned out to be +hard to use for driver development. + +GEM started as an Intel-sponsored project in reaction to TTM's +complexity. Its design philosophy is completely different: instead of +providing a solution to every graphics memory-related problems, GEM +identified common code between drivers and created a support library to +share it. GEM has simpler initialization and execution requirements than +TTM, but has no video RAM management capabilities and is thus limited to +UMA devices. + +The Translation Table Manager (TTM) +----------------------------------- + +TTM design background and information belongs here. + +TTM initialization +~~~~~~~~~~~~~~~~~~ + + **Warning** + + This section is outdated. + +Drivers wishing to support TTM must fill out a drm_bo_driver +structure. The structure contains several fields with function pointers +for initializing the TTM, allocating and freeing memory, waiting for +command completion and fence synchronization, and memory migration. See +the radeon_ttm.c file for an example of usage. + +The ttm_global_reference structure is made up of several fields: + +:: + + struct ttm_global_reference { + enum ttm_global_types global_type; + size_t size; + void *object; + int (*init) (struct ttm_global_reference *); + void (*release) (struct ttm_global_reference *); + }; + + +There should be one global reference structure for your memory manager +as a whole, and there will be others for each object created by the +memory manager at runtime. Your global TTM should have a type of +TTM_GLOBAL_TTM_MEM. The size field for the global object should be +sizeof(struct ttm_mem_global), and the init and release hooks should +point at your driver-specific init and release routines, which probably +eventually call ttm_mem_global_init and ttm_mem_global_release, +respectively. + +Once your global TTM accounting structure is set up and initialized by +calling ttm_global_item_ref() on it, you need to create a buffer +object TTM to provide a pool for buffer object allocation by clients and +the kernel itself. The type of this object should be +TTM_GLOBAL_TTM_BO, and its size should be sizeof(struct +ttm_bo_global). Again, driver-specific init and release functions may +be provided, likely eventually calling ttm_bo_global_init() and +ttm_bo_global_release(), respectively. Also, like the previous +object, ttm_global_item_ref() is used to create an initial reference +count for the TTM, which will call your initialization function. + +The Graphics Execution Manager (GEM) +------------------------------------ + +The GEM design approach has resulted in a memory manager that doesn't +provide full coverage of all (or even all common) use cases in its +userspace or kernel API. GEM exposes a set of standard memory-related +operations to userspace and a set of helper functions to drivers, and +let drivers implement hardware-specific operations with their own +private API. + +The GEM userspace API is described in the `GEM - the Graphics Execution +Manager `__ article on LWN. While +slightly outdated, the document provides a good overview of the GEM API +principles. Buffer allocation and read and write operations, described +as part of the common GEM API, are currently implemented using +driver-specific ioctls. + +GEM is data-agnostic. It manages abstract buffer objects without knowing +what individual buffers contain. APIs that require knowledge of buffer +contents or purpose, such as buffer allocation or synchronization +primitives, are thus outside of the scope of GEM and must be implemented +using driver-specific ioctls. + +On a fundamental level, GEM involves several operations: + +- Memory allocation and freeing +- Command execution +- Aperture management at command execution time + +Buffer object allocation is relatively straightforward and largely +provided by Linux's shmem layer, which provides memory to back each +object. + +Device-specific operations, such as command execution, pinning, buffer +read & write, mapping, and domain ownership transfers are left to +driver-specific ioctls. + +GEM Initialization +~~~~~~~~~~~~~~~~~~ + +Drivers that use GEM must set the DRIVER_GEM bit in the struct +:c:type:`struct drm_driver ` driver_features +field. The DRM core will then automatically initialize the GEM core +before calling the load operation. Behind the scene, this will create a +DRM Memory Manager object which provides an address space pool for +object allocation. + +In a KMS configuration, drivers need to allocate and initialize a +command ring buffer following core GEM initialization if required by the +hardware. UMA devices usually have what is called a "stolen" memory +region, which provides space for the initial framebuffer and large, +contiguous memory regions required by the device. This space is +typically not managed by GEM, and must be initialized separately into +its own DRM MM object. + +GEM Objects Creation +~~~~~~~~~~~~~~~~~~~~ + +GEM splits creation of GEM objects and allocation of the memory that +backs them in two distinct operations. + +GEM objects are represented by an instance of struct :c:type:`struct +drm_gem_object `. Drivers usually need to +extend GEM objects with private information and thus create a +driver-specific GEM object structure type that embeds an instance of +struct :c:type:`struct drm_gem_object `. + +To create a GEM object, a driver allocates memory for an instance of its +specific GEM object type and initializes the embedded struct +:c:type:`struct drm_gem_object ` with a call +to :c:func:`drm_gem_object_init()`. The function takes a pointer +to the DRM device, a pointer to the GEM object and the buffer object +size in bytes. + +GEM uses shmem to allocate anonymous pageable memory. +:c:func:`drm_gem_object_init()` will create an shmfs file of the +requested size and store it into the struct :c:type:`struct +drm_gem_object ` filp field. The memory is +used as either main storage for the object when the graphics hardware +uses system memory directly or as a backing store otherwise. + +Drivers are responsible for the actual physical pages allocation by +calling :c:func:`shmem_read_mapping_page_gfp()` for each page. +Note that they can decide to allocate pages when initializing the GEM +object, or to delay allocation until the memory is needed (for instance +when a page fault occurs as a result of a userspace memory access or +when the driver needs to start a DMA transfer involving the memory). + +Anonymous pageable memory allocation is not always desired, for instance +when the hardware requires physically contiguous system memory as is +often the case in embedded devices. Drivers can create GEM objects with +no shmfs backing (called private GEM objects) by initializing them with +a call to :c:func:`drm_gem_private_object_init()` instead of +:c:func:`drm_gem_object_init()`. Storage for private GEM objects +must be managed by drivers. + +GEM Objects Lifetime +~~~~~~~~~~~~~~~~~~~~ + +All GEM objects are reference-counted by the GEM core. References can be +acquired and release by :c:func:`calling +drm_gem_object_reference()` and +:c:func:`drm_gem_object_unreference()` respectively. The caller +must hold the :c:type:`struct drm_device ` +struct_mutex lock when calling +:c:func:`drm_gem_object_reference()`. As a convenience, GEM +provides :c:func:`drm_gem_object_unreference_unlocked()` +functions that can be called without holding the lock. + +When the last reference to a GEM object is released the GEM core calls +the :c:type:`struct drm_driver ` gem_free_object +operation. That operation is mandatory for GEM-enabled drivers and must +free the GEM object and all associated resources. + +void (\*gem_free_object) (struct drm_gem_object \*obj); Drivers are +responsible for freeing all GEM object resources. This includes the +resources created by the GEM core, which need to be released with +:c:func:`drm_gem_object_release()`. + +GEM Objects Naming +~~~~~~~~~~~~~~~~~~ + +Communication between userspace and the kernel refers to GEM objects +using local handles, global names or, more recently, file descriptors. +All of those are 32-bit integer values; the usual Linux kernel limits +apply to the file descriptors. + +GEM handles are local to a DRM file. Applications get a handle to a GEM +object through a driver-specific ioctl, and can use that handle to refer +to the GEM object in other standard or driver-specific ioctls. Closing a +DRM file handle frees all its GEM handles and dereferences the +associated GEM objects. + +To create a handle for a GEM object drivers call +:c:func:`drm_gem_handle_create()`. The function takes a pointer +to the DRM file and the GEM object and returns a locally unique handle. +When the handle is no longer needed drivers delete it with a call to +:c:func:`drm_gem_handle_delete()`. Finally the GEM object +associated with a handle can be retrieved by a call to +:c:func:`drm_gem_object_lookup()`. + +Handles don't take ownership of GEM objects, they only take a reference +to the object that will be dropped when the handle is destroyed. To +avoid leaking GEM objects, drivers must make sure they drop the +reference(s) they own (such as the initial reference taken at object +creation time) as appropriate, without any special consideration for the +handle. For example, in the particular case of combined GEM object and +handle creation in the implementation of the dumb_create operation, +drivers must drop the initial reference to the GEM object before +returning the handle. + +GEM names are similar in purpose to handles but are not local to DRM +files. They can be passed between processes to reference a GEM object +globally. Names can't be used directly to refer to objects in the DRM +API, applications must convert handles to names and names to handles +using the DRM_IOCTL_GEM_FLINK and DRM_IOCTL_GEM_OPEN ioctls +respectively. The conversion is handled by the DRM core without any +driver-specific support. + +GEM also supports buffer sharing with dma-buf file descriptors through +PRIME. GEM-based drivers must use the provided helpers functions to +implement the exporting and importing correctly. See ?. Since sharing +file descriptors is inherently more secure than the easily guessable and +global GEM names it is the preferred buffer sharing mechanism. Sharing +buffers through GEM names is only supported for legacy userspace. +Furthermore PRIME also allows cross-device buffer sharing since it is +based on dma-bufs. + +GEM Objects Mapping +~~~~~~~~~~~~~~~~~~~ + +Because mapping operations are fairly heavyweight GEM favours +read/write-like access to buffers, implemented through driver-specific +ioctls, over mapping buffers to userspace. However, when random access +to the buffer is needed (to perform software rendering for instance), +direct access to the object can be more efficient. + +The mmap system call can't be used directly to map GEM objects, as they +don't have their own file handle. Two alternative methods currently +co-exist to map GEM objects to userspace. The first method uses a +driver-specific ioctl to perform the mapping operation, calling +:c:func:`do_mmap()` under the hood. This is often considered +dubious, seems to be discouraged for new GEM-enabled drivers, and will +thus not be described here. + +The second method uses the mmap system call on the DRM file handle. void +\*mmap(void \*addr, size_t length, int prot, int flags, int fd, off_t +offset); DRM identifies the GEM object to be mapped by a fake offset +passed through the mmap offset argument. Prior to being mapped, a GEM +object must thus be associated with a fake offset. To do so, drivers +must call :c:func:`drm_gem_create_mmap_offset()` on the object. + +Once allocated, the fake offset value must be passed to the application +in a driver-specific way and can then be used as the mmap offset +argument. + +The GEM core provides a helper method :c:func:`drm_gem_mmap()` to +handle object mapping. The method can be set directly as the mmap file +operation handler. It will look up the GEM object based on the offset +value and set the VMA operations to the :c:type:`struct drm_driver +` gem_vm_ops field. Note that +:c:func:`drm_gem_mmap()` doesn't map memory to userspace, but +relies on the driver-provided fault handler to map pages individually. + +To use :c:func:`drm_gem_mmap()`, drivers must fill the struct +:c:type:`struct drm_driver ` gem_vm_ops field +with a pointer to VM operations. + +struct vm_operations_struct \*gem_vm_ops struct +vm_operations_struct { void (\*open)(struct vm_area_struct \* area); +void (\*close)(struct vm_area_struct \* area); int (\*fault)(struct +vm_area_struct \*vma, struct vm_fault \*vmf); }; + +The open and close operations must update the GEM object reference +count. Drivers can use the :c:func:`drm_gem_vm_open()` and +:c:func:`drm_gem_vm_close()` helper functions directly as open +and close handlers. + +The fault operation handler is responsible for mapping individual pages +to userspace when a page fault occurs. Depending on the memory +allocation scheme, drivers can allocate pages at fault time, or can +decide to allocate memory for the GEM object at the time the object is +created. + +Drivers that want to map the GEM object upfront instead of handling page +faults can implement their own mmap file operation handler. + +Memory Coherency +~~~~~~~~~~~~~~~~ + +When mapped to the device or used in a command buffer, backing pages for +an object are flushed to memory and marked write combined so as to be +coherent with the GPU. Likewise, if the CPU accesses an object after the +GPU has finished rendering to the object, then the object must be made +coherent with the CPU's view of memory, usually involving GPU cache +flushing of various kinds. This core CPU<->GPU coherency management is +provided by a device-specific ioctl, which evaluates an object's current +domain and performs any necessary flushing or synchronization to put the +object into the desired coherency domain (note that the object may be +busy, i.e. an active render target; in that case, setting the domain +blocks the client and waits for rendering to complete before performing +any necessary flushing operations). + +Command Execution +~~~~~~~~~~~~~~~~~ + +Perhaps the most important GEM function for GPU devices is providing a +command execution interface to clients. Client programs construct +command buffers containing references to previously allocated memory +objects, and then submit them to GEM. At that point, GEM takes care to +bind all the objects into the GTT, execute the buffer, and provide +necessary synchronization between clients accessing the same buffers. +This often involves evicting some objects from the GTT and re-binding +others (a fairly expensive operation), and providing relocation support +which hides fixed GTT offsets from clients. Clients must take care not +to submit command buffers that reference more objects than can fit in +the GTT; otherwise, GEM will reject them and no rendering will occur. +Similarly, if several objects in the buffer require fence registers to +be allocated for correct rendering (e.g. 2D blits on pre-965 chips), +care must be taken not to require more fence registers than are +available to the client. Such resource management should be abstracted +from the client in libdrm. + +GEM Function Reference +---------------------- + +.. kernel-doc:: drivers/gpu/drm/drm_gem.c + :export: + +.. kernel-doc:: include/drm/drm_gem.h + :internal: + +VMA Offset Manager +------------------ + +.. kernel-doc:: drivers/gpu/drm/drm_vma_manager.c + :doc: vma offset manager + +.. kernel-doc:: drivers/gpu/drm/drm_vma_manager.c + :export: + +.. kernel-doc:: include/drm/drm_vma_manager.h + :internal: + +PRIME Buffer Sharing +-------------------- + +PRIME is the cross device buffer sharing framework in drm, originally +created for the OPTIMUS range of multi-gpu platforms. To userspace PRIME +buffers are dma-buf based file descriptors. + +Overview and Driver Interface +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Similar to GEM global names, PRIME file descriptors are also used to +share buffer objects across processes. They offer additional security: +as file descriptors must be explicitly sent over UNIX domain sockets to +be shared between applications, they can't be guessed like the globally +unique GEM names. + +Drivers that support the PRIME API must set the DRIVER_PRIME bit in the +struct :c:type:`struct drm_driver ` +driver_features field, and implement the prime_handle_to_fd and +prime_fd_to_handle operations. + +int (\*prime_handle_to_fd)(struct drm_device \*dev, struct drm_file +\*file_priv, uint32_t handle, uint32_t flags, int \*prime_fd); int +(\*prime_fd_to_handle)(struct drm_device \*dev, struct drm_file +\*file_priv, int prime_fd, uint32_t \*handle); Those two operations +convert a handle to a PRIME file descriptor and vice versa. Drivers must +use the kernel dma-buf buffer sharing framework to manage the PRIME file +descriptors. Similar to the mode setting API PRIME is agnostic to the +underlying buffer object manager, as long as handles are 32bit unsigned +integers. + +While non-GEM drivers must implement the operations themselves, GEM +drivers must use the :c:func:`drm_gem_prime_handle_to_fd()` and +:c:func:`drm_gem_prime_fd_to_handle()` helper functions. Those +helpers rely on the driver gem_prime_export and gem_prime_import +operations to create a dma-buf instance from a GEM object (dma-buf +exporter role) and to create a GEM object from a dma-buf instance +(dma-buf importer role). + +struct dma_buf \* (\*gem_prime_export)(struct drm_device \*dev, +struct drm_gem_object \*obj, int flags); struct drm_gem_object \* +(\*gem_prime_import)(struct drm_device \*dev, struct dma_buf +\*dma_buf); These two operations are mandatory for GEM drivers that +support PRIME. + +PRIME Helper Functions +~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/gpu/drm/drm_prime.c + :doc: PRIME Helpers + +PRIME Function References +------------------------- + +.. kernel-doc:: drivers/gpu/drm/drm_prime.c + :export: + +DRM MM Range Allocator +---------------------- + +Overview +~~~~~~~~ + +.. kernel-doc:: drivers/gpu/drm/drm_mm.c + :doc: Overview + +LRU Scan/Eviction Support +~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/gpu/drm/drm_mm.c + :doc: lru scan roaster + +DRM MM Range Allocator Function References +------------------------------------------ + +.. kernel-doc:: drivers/gpu/drm/drm_mm.c + :export: + +.. kernel-doc:: include/drm/drm_mm.h + :internal: + +CMA Helper Functions Reference +------------------------------ + +.. kernel-doc:: drivers/gpu/drm/drm_gem_cma_helper.c + :doc: cma helpers + +.. kernel-doc:: drivers/gpu/drm/drm_gem_cma_helper.c + :export: + +.. kernel-doc:: include/drm/drm_gem_cma_helper.h + :internal: diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst new file mode 100644 index 000000000000..536bf3eaadd4 --- /dev/null +++ b/Documentation/gpu/drm-uapi.rst @@ -0,0 +1,111 @@ +=================== +Userland interfaces +=================== + +The DRM core exports several interfaces to applications, generally +intended to be used through corresponding libdrm wrapper functions. In +addition, drivers export device-specific interfaces for use by userspace +drivers & device-aware applications through ioctls and sysfs files. + +External interfaces include: memory mapping, context management, DMA +operations, AGP management, vblank control, fence management, memory +management, and output management. + +Cover generic ioctls and sysfs layout here. We only need high-level +info, since man pages should cover the rest. + +libdrm Device Lookup +==================== + +.. kernel-doc:: drivers/gpu/drm/drm_ioctl.c + :doc: getunique and setversion story + + +Primary Nodes, DRM Master and Authentication +============================================ + +.. kernel-doc:: drivers/gpu/drm/drm_auth.c + :doc: master and authentication + +.. kernel-doc:: drivers/gpu/drm/drm_auth.c + :export: + +.. kernel-doc:: include/drm/drm_auth.h + :internal: + +Render nodes +============ + +DRM core provides multiple character-devices for user-space to use. +Depending on which device is opened, user-space can perform a different +set of operations (mainly ioctls). The primary node is always created +and called card. Additionally, a currently unused control node, +called controlD is also created. The primary node provides all +legacy operations and historically was the only interface used by +userspace. With KMS, the control node was introduced. However, the +planned KMS control interface has never been written and so the control +node stays unused to date. + +With the increased use of offscreen renderers and GPGPU applications, +clients no longer require running compositors or graphics servers to +make use of a GPU. But the DRM API required unprivileged clients to +authenticate to a DRM-Master prior to getting GPU access. To avoid this +step and to grant clients GPU access without authenticating, render +nodes were introduced. Render nodes solely serve render clients, that +is, no modesetting or privileged ioctls can be issued on render nodes. +Only non-global rendering commands are allowed. If a driver supports +render nodes, it must advertise it via the DRIVER_RENDER DRM driver +capability. If not supported, the primary node must be used for render +clients together with the legacy drmAuth authentication procedure. + +If a driver advertises render node support, DRM core will create a +separate render node called renderD. There will be one render node +per device. No ioctls except PRIME-related ioctls will be allowed on +this node. Especially GEM_OPEN will be explicitly prohibited. Render +nodes are designed to avoid the buffer-leaks, which occur if clients +guess the flink names or mmap offsets on the legacy interface. +Additionally to this basic interface, drivers must mark their +driver-dependent render-only ioctls as DRM_RENDER_ALLOW so render +clients can use them. Driver authors must be careful not to allow any +privileged ioctls on render nodes. + +With render nodes, user-space can now control access to the render node +via basic file-system access-modes. A running graphics server which +authenticates clients on the privileged primary/legacy node is no longer +required. Instead, a client can open the render node and is immediately +granted GPU access. Communication between clients (or servers) is done +via PRIME. FLINK from render node to legacy node is not supported. New +clients must not use the insecure FLINK interface. + +Besides dropping all modeset/global ioctls, render nodes also drop the +DRM-Master concept. There is no reason to associate render clients with +a DRM-Master as they are independent of any graphics server. Besides, +they must work without any running master, anyway. Drivers must be able +to run without a master object if they support render nodes. If, on the +other hand, a driver requires shared state between clients which is +visible to user-space and accessible beyond open-file boundaries, they +cannot support render nodes. + +VBlank event handling +===================== + +The DRM core exposes two vertical blank related ioctls: + +DRM_IOCTL_WAIT_VBLANK + This takes a struct drm_wait_vblank structure as its argument, and + it is used to block or request a signal when a specified vblank + event occurs. + +DRM_IOCTL_MODESET_CTL + This was only used for user-mode-settind drivers around modesetting + changes to allow the kernel to update the vblank interrupt after + mode setting, since on many devices the vertical blank counter is + reset to 0 at some point during modeset. Modern drivers should not + call this any more since with kernel mode setting it is a no-op. + +This second part of the GPU Driver Developer's Guide documents driver +code, implementation details and also all the driver-specific userspace +interfaces. Especially since all hardware-acceleration interfaces to +userspace are driver specific for efficiency and other reasons these +interfaces can be rather substantial. Hence every driver has its own +chapter. diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst new file mode 100644 index 000000000000..2fe5952e90f1 --- /dev/null +++ b/Documentation/gpu/i915.rst @@ -0,0 +1,347 @@ +=========================== + drm/i915 Intel GFX Driver +=========================== + +The drm/i915 driver supports all (with the exception of some very early +models) integrated GFX chipsets with both Intel display and rendering +blocks. This excludes a set of SoC platforms with an SGX rendering unit, +those have basic support through the gma500 drm driver. + +Core Driver Infrastructure +========================== + +This section covers core driver infrastructure used by both the display +and the GEM parts of the driver. + +Runtime Power Management +------------------------ + +.. kernel-doc:: drivers/gpu/drm/i915/intel_runtime_pm.c + :doc: runtime pm + +.. kernel-doc:: drivers/gpu/drm/i915/intel_runtime_pm.c + :internal: + +.. kernel-doc:: drivers/gpu/drm/i915/intel_uncore.c + :internal: + +Interrupt Handling +------------------ + +.. kernel-doc:: drivers/gpu/drm/i915/i915_irq.c + :doc: interrupt handling + +.. kernel-doc:: drivers/gpu/drm/i915/i915_irq.c + :functions: intel_irq_init intel_irq_init_hw intel_hpd_init + +.. kernel-doc:: drivers/gpu/drm/i915/i915_irq.c + :functions: intel_runtime_pm_disable_interrupts + +.. kernel-doc:: drivers/gpu/drm/i915/i915_irq.c + :functions: intel_runtime_pm_enable_interrupts + +Intel GVT-g Guest Support(vGPU) +------------------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/i915_vgpu.c + :doc: Intel GVT-g guest support + +.. kernel-doc:: drivers/gpu/drm/i915/i915_vgpu.c + :internal: + +Display Hardware Handling +========================= + +This section covers everything related to the display hardware including +the mode setting infrastructure, plane, sprite and cursor handling and +display, output probing and related topics. + +Mode Setting Infrastructure +--------------------------- + +The i915 driver is thus far the only DRM driver which doesn't use the +common DRM helper code to implement mode setting sequences. Thus it has +its own tailor-made infrastructure for executing a display configuration +change. + +Frontbuffer Tracking +-------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_frontbuffer.c + :doc: frontbuffer tracking + +.. kernel-doc:: drivers/gpu/drm/i915/intel_frontbuffer.c + :internal: + +.. kernel-doc:: drivers/gpu/drm/i915/i915_gem.c + :functions: i915_gem_track_fb + +Display FIFO Underrun Reporting +------------------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_fifo_underrun.c + :doc: fifo underrun handling + +.. kernel-doc:: drivers/gpu/drm/i915/intel_fifo_underrun.c + :internal: + +Plane Configuration +------------------- + +This section covers plane configuration and composition with the primary +plane, sprites, cursors and overlays. This includes the infrastructure +to do atomic vsync'ed updates of all this state and also tightly coupled +topics like watermark setup and computation, framebuffer compression and +panel self refresh. + +Atomic Plane Helpers +-------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_atomic_plane.c + :doc: atomic plane helpers + +.. kernel-doc:: drivers/gpu/drm/i915/intel_atomic_plane.c + :internal: + +Output Probing +-------------- + +This section covers output probing and related infrastructure like the +hotplug interrupt storm detection and mitigation code. Note that the +i915 driver still uses most of the common DRM helper code for output +probing, so those sections fully apply. + +Hotplug +------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_hotplug.c + :doc: Hotplug + +.. kernel-doc:: drivers/gpu/drm/i915/intel_hotplug.c + :internal: + +High Definition Audio +--------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_audio.c + :doc: High Definition Audio over HDMI and Display Port + +.. kernel-doc:: drivers/gpu/drm/i915/intel_audio.c + :internal: + +.. kernel-doc:: include/drm/i915_component.h + :internal: + +Panel Self Refresh PSR (PSR/SRD) +-------------------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_psr.c + :doc: Panel Self Refresh (PSR/SRD) + +.. kernel-doc:: drivers/gpu/drm/i915/intel_psr.c + :internal: + +Frame Buffer Compression (FBC) +------------------------------ + +.. kernel-doc:: drivers/gpu/drm/i915/intel_fbc.c + :doc: Frame Buffer Compression (FBC) + +.. kernel-doc:: drivers/gpu/drm/i915/intel_fbc.c + :internal: + +Display Refresh Rate Switching (DRRS) +------------------------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c + :doc: Display Refresh Rate Switching (DRRS) + +.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c + :functions: intel_dp_set_drrs_state + +.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c + :functions: intel_edp_drrs_enable + +.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c + :functions: intel_edp_drrs_disable + +.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c + :functions: intel_edp_drrs_invalidate + +.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c + :functions: intel_edp_drrs_flush + +.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c + :functions: intel_dp_drrs_init + +DPIO +---- + +.. kernel-doc:: drivers/gpu/drm/i915/i915_reg.h + :doc: DPIO + +CSR firmware support for DMC +---------------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_csr.c + :doc: csr support for dmc + +.. kernel-doc:: drivers/gpu/drm/i915/intel_csr.c + :internal: + +Video BIOS Table (VBT) +---------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_bios.c + :doc: Video BIOS Table (VBT) + +.. kernel-doc:: drivers/gpu/drm/i915/intel_bios.c + :internal: + +.. kernel-doc:: drivers/gpu/drm/i915/intel_vbt_defs.h + :internal: + +Memory Management and Command Submission +======================================== + +This sections covers all things related to the GEM implementation in the +i915 driver. + +Batchbuffer Parsing +------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/i915_cmd_parser.c + :doc: batch buffer command parser + +.. kernel-doc:: drivers/gpu/drm/i915/i915_cmd_parser.c + :internal: + +Batchbuffer Pools +----------------- + +.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_batch_pool.c + :doc: batch pool + +.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_batch_pool.c + :internal: + +Logical Rings, Logical Ring Contexts and Execlists +-------------------------------------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_lrc.c + :doc: Logical Rings, Logical Ring Contexts and Execlists + +.. kernel-doc:: drivers/gpu/drm/i915/intel_lrc.c + :internal: + +Global GTT views +---------------- + +.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_gtt.c + :doc: Global GTT views + +.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_gtt.c + :internal: + +GTT Fences and Swizzling +------------------------ + +.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_fence.c + :internal: + +Global GTT Fence Handling +~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_fence.c + :doc: fence register handling + +Hardware Tiling and Swizzling Details +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_fence.c + :doc: tiling swizzling details + +Object Tiling IOCTLs +-------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_tiling.c + :internal: + +.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_tiling.c + :doc: buffer object tiling + +Buffer Object Eviction +---------------------- + +This section documents the interface functions for evicting buffer +objects to make space available in the virtual gpu address spaces. Note +that this is mostly orthogonal to shrinking buffer objects caches, which +has the goal to make main memory (shared with the gpu through the +unified memory architecture) available. + +.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_evict.c + :internal: + +Buffer Object Memory Shrinking +------------------------------ + +This section documents the interface function for shrinking memory usage +of buffer object caches. Shrinking is used to make main memory +available. Note that this is mostly orthogonal to evicting buffer +objects, which has the goal to make space in gpu virtual address spaces. + +.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_shrinker.c + :internal: + +GuC +=== + +GuC-specific firmware loader +---------------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_guc_loader.c + :doc: GuC-specific firmware loader + +.. kernel-doc:: drivers/gpu/drm/i915/intel_guc_loader.c + :internal: + +GuC-based command submission +---------------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/i915_guc_submission.c + :doc: GuC-based command submission + +.. kernel-doc:: drivers/gpu/drm/i915/i915_guc_submission.c + :internal: + +GuC Firmware Layout +------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/intel_guc_fwif.h + :doc: GuC Firmware Layout + +Tracing +======= + +This sections covers all things related to the tracepoints implemented +in the i915 driver. + +i915_ppgtt_create and i915_ppgtt_release +---------------------------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/i915_trace.h + :doc: i915_ppgtt_create and i915_ppgtt_release tracepoints + +i915_context_create and i915_context_free +----------------------------------------- + +.. kernel-doc:: drivers/gpu/drm/i915/i915_trace.h + :doc: i915_context_create and i915_context_free tracepoints + +switch_mm +--------- + +.. kernel-doc:: drivers/gpu/drm/i915/i915_trace.h + :doc: switch_mm tracepoint + +.. WARNING: DOCPROC directive not supported: !Cdrivers/gpu/drm/i915/i915_irq.c diff --git a/Documentation/gpu/index.rst b/Documentation/gpu/index.rst new file mode 100644 index 000000000000..fcac0fa72056 --- /dev/null +++ b/Documentation/gpu/index.rst @@ -0,0 +1,14 @@ +================================== +Linux GPU Driver Developer's Guide +================================== + +.. toctree:: + + introduction + drm-internals + drm-mm + drm-kms + drm-kms-helpers + drm-uapi + i915 + vga-switcheroo diff --git a/Documentation/gpu/introduction.rst b/Documentation/gpu/introduction.rst new file mode 100644 index 000000000000..1903595b5310 --- /dev/null +++ b/Documentation/gpu/introduction.rst @@ -0,0 +1,51 @@ +============ +Introduction +============ + +The Linux DRM layer contains code intended to support the needs of +complex graphics devices, usually containing programmable pipelines well +suited to 3D graphics acceleration. Graphics drivers in the kernel may +make use of DRM functions to make tasks like memory management, +interrupt handling and DMA easier, and provide a uniform interface to +applications. + +A note on versions: this guide covers features found in the DRM tree, +including the TTM memory manager, output configuration and mode setting, +and the new vblank internals, in addition to all the regular features +found in current kernels. + +[Insert diagram of typical DRM stack here] + +Style Guidelines +================ + +For consistency this documentation uses American English. Abbreviations +are written as all-uppercase, for example: DRM, KMS, IOCTL, CRTC, and so +on. To aid in reading, documentations make full use of the markup +characters kerneldoc provides: @parameter for function parameters, +@member for structure members, &structure to reference structures and +function() for functions. These all get automatically hyperlinked if +kerneldoc for the referenced objects exists. When referencing entries in +function vtables please use ->vfunc(). Note that kerneldoc does not +support referencing struct members directly, so please add a reference +to the vtable struct somewhere in the same paragraph or at least +section. + +Except in special situations (to separate locked from unlocked variants) +locking requirements for functions aren't documented in the kerneldoc. +Instead locking should be check at runtime using e.g. +``WARN_ON(!mutex_is_locked(...));``. Since it's much easier to ignore +documentation than runtime noise this provides more value. And on top of +that runtime checks do need to be updated when the locking rules change, +increasing the chances that they're correct. Within the documentation +the locking rules should be explained in the relevant structures: Either +in the comment for the lock explaining what it protects, or data fields +need a note about which lock protects them, or both. + +Functions which have a non-\ ``void`` return value should have a section +called "Returns" explaining the expected return values in different +cases and their meanings. Currently there's no consensus whether that +section name should be all upper-case or not, and whether it should end +in a colon or not. Go with the file-local style. Other common section +names are "Notes" with information for dangerous or tricky corner cases, +and "FIXME" where the interface could be cleaned up. diff --git a/Documentation/gpu/kms-properties.csv b/Documentation/gpu/kms-properties.csv new file mode 100644 index 000000000000..b6fcaf639c04 --- /dev/null +++ b/Documentation/gpu/kms-properties.csv @@ -0,0 +1,128 @@ +Owner Module/Drivers,Group,Property Name,Type,Property Values,Object attached,Description/Restrictions +DRM,Generic,“rotation”,BITMASK,"{ 0, ""rotate-0"" }, { 1, ""rotate-90"" }, { 2, ""rotate-180"" }, { 3, ""rotate-270"" }, { 4, ""reflect-x"" }, { 5, ""reflect-y"" }","CRTC, Plane",rotate-(degrees) rotates the image by the specified amount in degrees in counter clockwise direction. reflect-x and reflect-y reflects the image along the specified axis prior to rotation +,,“scaling mode”,ENUM,"{ ""None"", ""Full"", ""Center"", ""Full aspect"" }",Connector,"Supported by: amdgpu, gma500, i915, nouveau and radeon." +,Connector,“EDID”,BLOB | IMMUTABLE,0,Connector,Contains id of edid blob ptr object. +,,“DPMS”,ENUM,"{ “On”, “Standby”, “Suspend”, “Off” }",Connector,Contains DPMS operation mode value. +,,“PATH”,BLOB | IMMUTABLE,0,Connector,Contains topology path to a connector. +,,“TILE”,BLOB | IMMUTABLE,0,Connector,Contains tiling information for a connector. +,,“CRTC_ID”,OBJECT,DRM_MODE_OBJECT_CRTC,Connector,CRTC that connector is attached to (atomic) +,Plane,“type”,ENUM | IMMUTABLE,"{ ""Overlay"", ""Primary"", ""Cursor"" }",Plane,Plane type +,,“SRC_X”,RANGE,"Min=0, Max=UINT_MAX",Plane,Scanout source x coordinate in 16.16 fixed point (atomic) +,,“SRC_Y”,RANGE,"Min=0, Max=UINT_MAX",Plane,Scanout source y coordinate in 16.16 fixed point (atomic) +,,“SRC_W”,RANGE,"Min=0, Max=UINT_MAX",Plane,Scanout source width in 16.16 fixed point (atomic) +,,“SRC_H”,RANGE,"Min=0, Max=UINT_MAX",Plane,Scanout source height in 16.16 fixed point (atomic) +,,“CRTC_X”,SIGNED_RANGE,"Min=INT_MIN, Max=INT_MAX",Plane,Scanout CRTC (destination) x coordinate (atomic) +,,“CRTC_Y”,SIGNED_RANGE,"Min=INT_MIN, Max=INT_MAX",Plane,Scanout CRTC (destination) y coordinate (atomic) +,,“CRTC_W”,RANGE,"Min=0, Max=UINT_MAX",Plane,Scanout CRTC (destination) width (atomic) +,,“CRTC_H”,RANGE,"Min=0, Max=UINT_MAX",Plane,Scanout CRTC (destination) height (atomic) +,,“FB_ID”,OBJECT,DRM_MODE_OBJECT_FB,Plane,Scanout framebuffer (atomic) +,,“CRTC_ID”,OBJECT,DRM_MODE_OBJECT_CRTC,Plane,CRTC that plane is attached to (atomic) +,DVI-I,“subconnector”,ENUM,"{ “Unknown”, “DVI-D”, “DVI-A” }",Connector,TBD +,,“select subconnector”,ENUM,"{ “Automatic”, “DVI-D”, “DVI-A” }",Connector,TBD +,TV,“subconnector”,ENUM,"{ ""Unknown"", ""Composite"", ""SVIDEO"", ""Component"", ""SCART"" }",Connector,TBD +,,“select subconnector”,ENUM,"{ ""Automatic"", ""Composite"", ""SVIDEO"", ""Component"", ""SCART"" }",Connector,TBD +,,“mode”,ENUM,"{ ""NTSC_M"", ""NTSC_J"", ""NTSC_443"", ""PAL_B"" } etc.",Connector,TBD +,,“left margin”,RANGE,"Min=0, Max=100",Connector,TBD +,,“right margin”,RANGE,"Min=0, Max=100",Connector,TBD +,,“top margin”,RANGE,"Min=0, Max=100",Connector,TBD +,,“bottom margin”,RANGE,"Min=0, Max=100",Connector,TBD +,,“brightness”,RANGE,"Min=0, Max=100",Connector,TBD +,,“contrast”,RANGE,"Min=0, Max=100",Connector,TBD +,,“flicker reduction”,RANGE,"Min=0, Max=100",Connector,TBD +,,“overscan”,RANGE,"Min=0, Max=100",Connector,TBD +,,“saturation”,RANGE,"Min=0, Max=100",Connector,TBD +,,“hue”,RANGE,"Min=0, Max=100",Connector,TBD +,Virtual GPU,“suggested X”,RANGE,"Min=0, Max=0xffffffff",Connector,property to suggest an X offset for a connector +,,“suggested Y”,RANGE,"Min=0, Max=0xffffffff",Connector,property to suggest an Y offset for a connector +,Optional,"""aspect ratio""",ENUM,"{ ""None"", ""4:3"", ""16:9"" }",Connector,TDB +,,“dirty”,ENUM | IMMUTABLE,"{ ""Off"", ""On"", ""Annotate"" }",Connector,TBD +,,“DEGAMMA_LUT”,BLOB,0,CRTC,DRM property to set the degamma lookup table (LUT) mapping pixel data from the framebuffer before it is given to the transformation matrix. The data is an interpreted as an array of struct drm_color_lut elements. Hardware might choose not to use the full precision of the LUT elements nor use all the elements of the LUT (for example the hardware might choose to interpolate between LUT[0] and LUT[4]). +,,“DEGAMMA_LUT_SIZE”,RANGE | IMMUTABLE,"Min=0, Max=UINT_MAX",CRTC,DRM property to gives the size of the lookup table to be set on the DEGAMMA_LUT property (the size depends on the underlying hardware). +,,“CTM”,BLOB,0,CRTC,DRM property to set the current transformation matrix (CTM) apply to pixel data after the lookup through the degamma LUT and before the lookup through the gamma LUT. The data is an interpreted as a struct drm_color_ctm. +,,“GAMMA_LUT”,BLOB,0,CRTC,DRM property to set the gamma lookup table (LUT) mapping pixel data after to the transformation matrix to data sent to the connector. The data is an interpreted as an array of struct drm_color_lut elements. Hardware might choose not to use the full precision of the LUT elements nor use all the elements of the LUT (for example the hardware might choose to interpolate between LUT[0] and LUT[4]). +,,“GAMMA_LUT_SIZE”,RANGE | IMMUTABLE,"Min=0, Max=UINT_MAX",CRTC,DRM property to gives the size of the lookup table to be set on the GAMMA_LUT property (the size depends on the underlying hardware). +i915,Generic,"""Broadcast RGB""",ENUM,"{ ""Automatic"", ""Full"", ""Limited 16:235"" }",Connector,"When this property is set to Limited 16:235 and CTM is set, the hardware will be programmed with the result of the multiplication of CTM by the limited range matrix to ensure the pixels normaly in the range 0..1.0 are remapped to the range 16/255..235/255." +,,“audio”,ENUM,"{ ""force-dvi"", ""off"", ""auto"", ""on"" }",Connector,TBD +,SDVO-TV,“mode”,ENUM,"{ ""NTSC_M"", ""NTSC_J"", ""NTSC_443"", ""PAL_B"" } etc.",Connector,TBD +,,"""left_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,"""right_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,"""top_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,"""bottom_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“hpos”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“vpos”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“contrast”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“saturation”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“hue”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“sharpness”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“flicker_filter”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“flicker_filter_adaptive”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“flicker_filter_2d”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“tv_chroma_filter”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“tv_luma_filter”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“dot_crawl”,RANGE,"Min=0, Max=1",Connector,TBD +,SDVO-TV/LVDS,“brightness”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +CDV gma-500,Generic,"""Broadcast RGB""",ENUM,"{ “Full”, “Limited 16:235” }",Connector,TBD +,,"""Broadcast RGB""",ENUM,"{ “off”, “auto”, “on” }",Connector,TBD +Poulsbo,Generic,“backlight”,RANGE,"Min=0, Max=100",Connector,TBD +,SDVO-TV,“mode”,ENUM,"{ ""NTSC_M"", ""NTSC_J"", ""NTSC_443"", ""PAL_B"" } etc.",Connector,TBD +,,"""left_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,"""right_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,"""top_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,"""bottom_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“hpos”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“vpos”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“contrast”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“saturation”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“hue”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“sharpness”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“flicker_filter”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“flicker_filter_adaptive”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“flicker_filter_2d”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“tv_chroma_filter”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“tv_luma_filter”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +,,“dot_crawl”,RANGE,"Min=0, Max=1",Connector,TBD +,SDVO-TV/LVDS,“brightness”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD +armada,CRTC,"""CSC_YUV""",ENUM,"{ ""Auto"" , ""CCIR601"", ""CCIR709"" }",CRTC,TBD +,,"""CSC_RGB""",ENUM,"{ ""Auto"", ""Computer system"", ""Studio"" }",CRTC,TBD +,Overlay,"""colorkey""",RANGE,"Min=0, Max=0xffffff",Plane,TBD +,,"""colorkey_min""",RANGE,"Min=0, Max=0xffffff",Plane,TBD +,,"""colorkey_max""",RANGE,"Min=0, Max=0xffffff",Plane,TBD +,,"""colorkey_val""",RANGE,"Min=0, Max=0xffffff",Plane,TBD +,,"""colorkey_alpha""",RANGE,"Min=0, Max=0xffffff",Plane,TBD +,,"""colorkey_mode""",ENUM,"{ ""disabled"", ""Y component"", ""U component"" , ""V component"", ""RGB"", “R component"", ""G component"", ""B component"" }",Plane,TBD +,,"""brightness""",RANGE,"Min=0, Max=256 + 255",Plane,TBD +,,"""contrast""",RANGE,"Min=0, Max=0x7fff",Plane,TBD +,,"""saturation""",RANGE,"Min=0, Max=0x7fff",Plane,TBD +exynos,CRTC,“mode”,ENUM,"{ ""normal"", ""blank"" }",CRTC,TBD +,Overlay,“zpos”,RANGE,"Min=0, Max=MAX_PLANE-1",Plane,TBD +i2c/ch7006_drv,Generic,“scale”,RANGE,"Min=0, Max=2",Connector,TBD +,TV,“mode”,ENUM,"{ ""PAL"", ""PAL-M"",""PAL-N""}, ”PAL-Nc"" , ""PAL-60"", ""NTSC-M"", ""NTSC-J"" }",Connector,TBD +nouveau,NV10 Overlay,"""colorkey""",RANGE,"Min=0, Max=0x01ffffff",Plane,TBD +,,“contrast”,RANGE,"Min=0, Max=8192-1",Plane,TBD +,,“brightness”,RANGE,"Min=0, Max=1024",Plane,TBD +,,“hue”,RANGE,"Min=0, Max=359",Plane,TBD +,,“saturation”,RANGE,"Min=0, Max=8192-1",Plane,TBD +,,“iturbt_709”,RANGE,"Min=0, Max=1",Plane,TBD +,Nv04 Overlay,“colorkey”,RANGE,"Min=0, Max=0x01ffffff",Plane,TBD +,,“brightness”,RANGE,"Min=0, Max=1024",Plane,TBD +,Display,“dithering mode”,ENUM,"{ ""auto"", ""off"", ""on"" }",Connector,TBD +,,“dithering depth”,ENUM,"{ ""auto"", ""off"", ""on"", ""static 2x2"", ""dynamic 2x2"", ""temporal"" }",Connector,TBD +,,“underscan”,ENUM,"{ ""auto"", ""6 bpc"", ""8 bpc"" }",Connector,TBD +,,“underscan hborder”,RANGE,"Min=0, Max=128",Connector,TBD +,,“underscan vborder”,RANGE,"Min=0, Max=128",Connector,TBD +,,“vibrant hue”,RANGE,"Min=0, Max=180",Connector,TBD +,,“color vibrance”,RANGE,"Min=0, Max=200",Connector,TBD +omap,Generic,“zorder”,RANGE,"Min=0, Max=3","CRTC, Plane",TBD +qxl,Generic,"“hotplug_mode_update""",RANGE,"Min=0, Max=1",Connector,TBD +radeon,DVI-I,“coherent”,RANGE,"Min=0, Max=1",Connector,TBD +,DAC enable load detect,“load detection”,RANGE,"Min=0, Max=1",Connector,TBD +,TV Standard,"""tv standard""",ENUM,"{ ""ntsc"", ""pal"", ""pal-m"", ""pal-60"", ""ntsc-j"" , ""scart-pal"", ""pal-cn"", ""secam"" }",Connector,TBD +,legacy TMDS PLL detect,"""tmds_pll""",ENUM,"{ ""driver"", ""bios"" }",-,TBD +,Underscan,"""underscan""",ENUM,"{ ""off"", ""on"", ""auto"" }",Connector,TBD +,,"""underscan hborder""",RANGE,"Min=0, Max=128",Connector,TBD +,,"""underscan vborder""",RANGE,"Min=0, Max=128",Connector,TBD +,Audio,“audio”,ENUM,"{ ""off"", ""on"", ""auto"" }",Connector,TBD +,FMT Dithering,“dither”,ENUM,"{ ""off"", ""on"" }",Connector,TBD +rcar-du,Generic,"""alpha""",RANGE,"Min=0, Max=255",Plane,TBD +,,"""colorkey""",RANGE,"Min=0, Max=0x01ffffff",Plane,TBD +,,"""zpos""",RANGE,"Min=1, Max=7",Plane,TBD diff --git a/Documentation/gpu/vga-switcheroo.rst b/Documentation/gpu/vga-switcheroo.rst new file mode 100644 index 000000000000..327d930a2229 --- /dev/null +++ b/Documentation/gpu/vga-switcheroo.rst @@ -0,0 +1,102 @@ +============== +VGA Switcheroo +============== + +.. kernel-doc:: drivers/gpu/vga/vga_switcheroo.c + :doc: Overview + +Modes of Use +============ + +Manual switching and manual power control +----------------------------------------- + +.. kernel-doc:: drivers/gpu/vga/vga_switcheroo.c + :doc: Manual switching and manual power control + +Driver power control +-------------------- + +.. kernel-doc:: drivers/gpu/vga/vga_switcheroo.c + :doc: Driver power control + +API +=== + +Public functions +---------------- + +.. kernel-doc:: drivers/gpu/vga/vga_switcheroo.c + :export: + +Public structures +----------------- + +.. kernel-doc:: include/linux/vga_switcheroo.h + :functions: vga_switcheroo_handler + +.. kernel-doc:: include/linux/vga_switcheroo.h + :functions: vga_switcheroo_client_ops + +Public constants +---------------- + +.. kernel-doc:: include/linux/vga_switcheroo.h + :functions: vga_switcheroo_handler_flags_t + +.. kernel-doc:: include/linux/vga_switcheroo.h + :functions: vga_switcheroo_client_id + +.. kernel-doc:: include/linux/vga_switcheroo.h + :functions: vga_switcheroo_state + +Private structures +------------------ + +.. kernel-doc:: drivers/gpu/vga/vga_switcheroo.c + :functions: vgasr_priv + +.. kernel-doc:: drivers/gpu/vga/vga_switcheroo.c + :functions: vga_switcheroo_client + +Handlers +======== + +apple-gmux Handler +------------------ + +.. kernel-doc:: drivers/platform/x86/apple-gmux.c + :doc: Overview + +.. kernel-doc:: drivers/platform/x86/apple-gmux.c + :doc: Interrupt + +Graphics mux +~~~~~~~~~~~~ + +.. kernel-doc:: drivers/platform/x86/apple-gmux.c + :doc: Graphics mux + +Power control +~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/platform/x86/apple-gmux.c + :doc: Power control + +Backlight control +~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/platform/x86/apple-gmux.c + :doc: Backlight control + +Public functions +~~~~~~~~~~~~~~~~ + +.. kernel-doc:: include/linux/apple-gmux.h + :internal: + +.. WARNING: DOCPROC directive not supported: !Cdrivers/gpu/vga/vga_switcheroo.c + +.. WARNING: DOCPROC directive not supported: !Cinclude/linux/vga_switcheroo.h + +.. WARNING: DOCPROC directive not supported: !Cdrivers/platform/x86/apple-gmux.c diff --git a/Documentation/index.rst b/Documentation/index.rst index 71a276f34c7f..dacc77b43c29 100644 --- a/Documentation/index.rst +++ b/Documentation/index.rst @@ -13,6 +13,7 @@ Contents: .. toctree:: :maxdepth: 2 + gpu/index Indices and tables ================== diff --git a/MAINTAINERS b/MAINTAINERS index cb88f724e07c..512185c9b768 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -865,9 +865,17 @@ F: Documentation/devicetree/bindings/display/snps,arcpgu.txt ARM HDLCD DRM DRIVER M: Liviu Dudau S: Supported -F: drivers/gpu/drm/arm/ +F: drivers/gpu/drm/arm/hdlcd_* F: Documentation/devicetree/bindings/display/arm,hdlcd.txt +ARM MALI-DP DRM DRIVER +M: Liviu Dudau +M: Brian Starkey +M: Mali DP Maintainers +S: Supported +F: drivers/gpu/drm/arm/ +F: Documentation/devicetree/bindings/display/arm,malidp.txt + ARM MFM AND FLOPPY DRIVERS M: Ian Molton S: Maintained @@ -3857,7 +3865,7 @@ F: drivers/gpu/vga/ F: Documentation/devicetree/bindings/display/ F: Documentation/devicetree/bindings/gpu/ F: Documentation/devicetree/bindings/video/ -F: Documentation/DocBook/gpu.* +F: Documentation/gpu/ F: include/drm/ F: include/uapi/drm/ @@ -3909,6 +3917,7 @@ S: Supported F: drivers/gpu/drm/i915/ F: include/drm/i915* F: include/uapi/drm/i915_drm.h +F: Documentation/gpu/i915.rst DRM DRIVERS FOR ATMEL HLCDC M: Boris Brezillon diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 6355ab38d630..20ce0687b111 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -824,7 +824,7 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) EXPORT_SYMBOL_GPL(dma_buf_vunmap); #ifdef CONFIG_DEBUG_FS -static int dma_buf_describe(struct seq_file *s) +static int dma_buf_debug_show(struct seq_file *s, void *unused) { int ret; struct dma_buf *buf_obj; @@ -879,17 +879,9 @@ static int dma_buf_describe(struct seq_file *s) return 0; } -static int dma_buf_show(struct seq_file *s, void *unused) -{ - void (*func)(struct seq_file *) = s->private; - - func(s); - return 0; -} - static int dma_buf_debug_open(struct inode *inode, struct file *file) { - return single_open(file, dma_buf_show, inode->i_private); + return single_open(file, dma_buf_debug_show, NULL); } static const struct file_operations dma_buf_debug_fops = { @@ -903,20 +895,23 @@ static struct dentry *dma_buf_debugfs_dir; static int dma_buf_init_debugfs(void) { + struct dentry *d; int err = 0; - dma_buf_debugfs_dir = debugfs_create_dir("dma_buf", NULL); + d = debugfs_create_dir("dma_buf", NULL); + if (IS_ERR(d)) + return PTR_ERR(d); - if (IS_ERR(dma_buf_debugfs_dir)) { - err = PTR_ERR(dma_buf_debugfs_dir); - dma_buf_debugfs_dir = NULL; - return err; - } + dma_buf_debugfs_dir = d; - err = dma_buf_debugfs_create_file("bufinfo", dma_buf_describe); - - if (err) + d = debugfs_create_file("bufinfo", S_IRUGO, dma_buf_debugfs_dir, + NULL, &dma_buf_debug_fops); + if (IS_ERR(d)) { pr_debug("dma_buf: debugfs: failed to create node bufinfo\n"); + debugfs_remove_recursive(dma_buf_debugfs_dir); + dma_buf_debugfs_dir = NULL; + err = PTR_ERR(d); + } return err; } @@ -926,17 +921,6 @@ static void dma_buf_uninit_debugfs(void) if (dma_buf_debugfs_dir) debugfs_remove_recursive(dma_buf_debugfs_dir); } - -int dma_buf_debugfs_create_file(const char *name, - int (*write)(struct seq_file *)) -{ - struct dentry *d; - - d = debugfs_create_file(name, S_IRUGO, dma_buf_debugfs_dir, - write, &dma_buf_debug_fops); - - return PTR_ERR_OR_ZERO(d); -} #else static inline int dma_buf_init_debugfs(void) { diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h index ec4036a09f3e..a625b9137da2 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h @@ -187,12 +187,12 @@ int init_pipelines(struct device_queue_manager *dqm, unsigned int get_first_pipe(struct device_queue_manager *dqm); unsigned int get_pipes_num(struct device_queue_manager *dqm); -extern inline unsigned int get_sh_mem_bases_32(struct kfd_process_device *pdd) +static inline unsigned int get_sh_mem_bases_32(struct kfd_process_device *pdd) { return (pdd->lds_base >> 16) & 0xFF; } -extern inline unsigned int +static inline unsigned int get_sh_mem_bases_nybble_64(struct kfd_process_device *pdd) { return (pdd->lds_base >> 60) & 0x0E; diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h index d0d5f4baf72d..80113c335966 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h @@ -617,10 +617,7 @@ int kgd2kfd_resume(struct kfd_dev *kfd); int kfd_init_apertures(struct kfd_process *process); /* Queue Context Management */ -inline uint32_t lower_32(uint64_t x); -inline uint32_t upper_32(uint64_t x); struct cik_sdma_rlc_registers *get_sdma_mqd(void *mqd); -inline uint32_t get_sdma_base_addr(struct cik_sdma_rlc_registers *m); int init_queue(struct queue **q, struct queue_properties properties); void uninit_queue(struct queue *q); diff --git a/drivers/gpu/drm/arc/arcpgu_drv.c b/drivers/gpu/drm/arc/arcpgu_drv.c index 381c5fcbf903..ccbdadb108dc 100644 --- a/drivers/gpu/drm/arc/arcpgu_drv.c +++ b/drivers/gpu/drm/arc/arcpgu_drv.c @@ -211,15 +211,8 @@ static int arcpgu_probe(struct platform_device *pdev) if (ret) goto err_unload; - ret = drm_connector_register_all(drm); - if (ret) - goto err_unregister; - return 0; -err_unregister: - drm_dev_unregister(drm); - err_unload: arcpgu_unload(drm); @@ -233,7 +226,6 @@ static int arcpgu_remove(struct platform_device *pdev) { struct drm_device *drm = platform_get_drvdata(pdev); - drm_connector_unregister_all(drm); drm_dev_unregister(drm); arcpgu_unload(drm); drm_dev_unref(drm); diff --git a/drivers/gpu/drm/arm/Kconfig b/drivers/gpu/drm/arm/Kconfig index eaed454e043c..1b2906568a48 100644 --- a/drivers/gpu/drm/arm/Kconfig +++ b/drivers/gpu/drm/arm/Kconfig @@ -25,3 +25,19 @@ config DRM_HDLCD_SHOW_UNDERRUN Enable this option to show in red colour the pixels that the HDLCD device did not fetch from framebuffer due to underrun conditions. + +config DRM_MALI_DISPLAY + tristate "ARM Mali Display Processor" + depends on DRM && OF && (ARM || ARM64) + depends on COMMON_CLK + select DRM_ARM + select DRM_KMS_HELPER + select DRM_KMS_CMA_HELPER + select DRM_GEM_CMA_HELPER + select VIDEOMODE_HELPERS + help + Choose this option if you want to compile the ARM Mali Display + Processor driver. It supports the DP500, DP550 and DP650 variants + of the hardware. + + If compiled as a module it will be called mali-dp. diff --git a/drivers/gpu/drm/arm/Makefile b/drivers/gpu/drm/arm/Makefile index 89dcb7bab93a..bb8b158ff90d 100644 --- a/drivers/gpu/drm/arm/Makefile +++ b/drivers/gpu/drm/arm/Makefile @@ -1,2 +1,4 @@ hdlcd-y := hdlcd_drv.o hdlcd_crtc.o obj-$(CONFIG_DRM_HDLCD) += hdlcd.o +mali-dp-y := malidp_drv.o malidp_hw.o malidp_planes.o malidp_crtc.o +obj-$(CONFIG_DRM_MALI_DISPLAY) += mali-dp.o diff --git a/drivers/gpu/drm/arm/malidp_crtc.c b/drivers/gpu/drm/arm/malidp_crtc.c new file mode 100644 index 000000000000..08e6a71f5d05 --- /dev/null +++ b/drivers/gpu/drm/arm/malidp_crtc.c @@ -0,0 +1,216 @@ +/* + * (C) COPYRIGHT 2016 ARM Limited. All rights reserved. + * Author: Liviu Dudau + * + * This program is free software and is provided to you under the terms of the + * GNU General Public License version 2 as published by the Free Software + * Foundation, and any use by you of this program is subject to the terms + * of such GNU licence. + * + * ARM Mali DP500/DP550/DP650 driver (crtc operations) + */ + +#include +#include +#include +#include +#include +#include +#include