Commit Graph

10 Commits

Author SHA1 Message Date
Sinan Kaya 5e2db086be dmaengine: qcom_hidma: introduce memset support
HIDMA HW supports memset operation in addition to memcpy.
Since the memset API is present on the kernel now, bring the
memset feature into life.

The descriptor format is the same for both memcpy and memset.
Type of the descriptor is 4 when memset is requested.
The lowest 8 bits of the source DMA argument is used as a
fill pattern.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-07-19 09:33:21 +05:30
Sinan Kaya 99efdb3e48 dmaengine: qcom_hidma: correct API violation for submit
Current code is violating the DMA Engine API by putting the submitted
requests directly into the HW queue. This causes queued transactions
to be started by another thread as soon as the first one finishes.

The DMA Engine document clearly states this.

"dmaengine_submit() will not start the DMA operation".

Move HW queuing of the requests into the issue_pending() routine
to comply with API requirements also create a new queued state for
temporarily holding the requests.

A descriptor goes through these transitions now.

free->prepared->queued->active->completed->free

as opposed to

free->prepared->active->completed->free

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-07-03 10:39:51 +05:30
Sinan Kaya c6e4584dab dmaengine: qcom_hidma: cleanup sysfs entries during remove
The 4.8-rc8 kernel is printing duplicate file entry warnings while removing
the HIDMA object. This is caused by stale sysfs entries remaining from the
previous execution.

_sysfs_warn_dup+0x5c/0x78
 sysfs_add_file_mode_ns+0x13c/0x1c0
 sysfs_create_file_ns+0x2c/0x40
 device_create_file+0x54/0xa0
 hidma_probe+0x7c8/0x808

Create hidma_sysfs_init and hidma_sysfs_uninit functions and call them from
the probe and remove path. To do proper clean up, adding the attrs object
to the device data structure to keep it around until remove call is made.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-11-15 08:58:12 +05:30
Sinan Kaya 1c0e3e82a7 dmaengine: qcom_hidma: add MSI support for interrupts
The interrupts can now be delivered as platform MSI interrupts on newer
platforms. The code looks for a new OF and ACPI strings in order to enable
the functionality.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-11-03 18:55:45 +05:30
Sinan Kaya bdcfddfd74 dmaengine: qcom_hidma: make pending_tre_count atomic
Getting ready for the MSI interrupts. The pending_tre_count is used
in the interrupt handler to make sure all outstanding requests are
serviced.

The driver will allocate 11 MSI interrupts. Each MSI interrupt can be
assigned to a different CPU. Then, we have a race condition for common
variables as they share the same interrupt handler with a different
cause bit and they can potentially be executed in parallel. Making this
variable atomic so that it can be updated from multiple processor
contexts.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-11-03 18:55:44 +05:30
Sinan Kaya d3eab504d4 dmaengine: qcom_hidma: add a common API to setup the interrupt
Introducing the hidma_ll_setup_irq function to set up the interrupt
type externally from the OS interface.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-10-19 19:03:05 +05:30
Sinan Kaya 793ae66c7d dmaengine: qcom_hidma: add error reporting for tx_status
The HIDMA driver is capable of error detection. However, the error was
not being passed back to the client when tx_status API is called.

Changing the error handling behavior to follow this oder.

1. dmaengine asserts error interrupt
2. Driver receives and mark's the txn as error
3. Driver completes the txn and intimates the client. No further
   submissions. Drop the locks before calling callback, as subsequent
   processing by client maybe in callback thread.
4. Client invokes status and you can return error
5. On error, client calls terminate_all. You can reset channel, free all
   descriptors in the active, pending and completed lists
6. Client prepares new txn and so on.

As part of this work, got rid of the reset in the interrupt handler when
an error happens and the HW is put into disabled state. The only way to
recover is for the client to terminate the channel.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-08-31 21:27:32 +05:30
Sinan Kaya 570d017629 dmaengine: qcom_hidma: add debugfs hooks
Add debugfs hooks for debugging the execution behavior of the DMA
channel. The debugfs hooks get initialized by the probe function and
uninitialized by the remove function.

A stats file is created in debugfs. The stats file will show the
information about each HIDMA channel as well as each asynchronous job
queued and completed at a given time.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-05-14 11:54:45 +05:30
Sinan Kaya d1615ca2e0 dmaengine: qcom_hidma: implement lower level hardware interface
This patch implements the hardware hooks for the HIDMA channel driver.

The main functions of interest are:
- hidma_ll_init
- hidma_ll_request
- hidma_ll_queue_request
- hidma_ll_hw_start

OS layer calls the hidma_ll_init function during probe to set up the
hardware. At this moment, the number of supported descriptors are also
given. On each request, a descriptor is allocated from the free pool and
filled in with the transfer parameters. Multiple requests can be queued
into the hardware via the OS interface. When client is ready for requests
to be executed, start method is called.

Completions are delivered via callbacks via tasklet.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-05-14 11:54:45 +05:30
Sinan Kaya 67a2003e06 dmaengine: add Qualcomm Technologies HIDMA channel driver
This patch adds support for hidma engine. The driver consists of two
logical blocks. The DMA engine interface and the low-level interface.
The hardware only supports memcpy/memset and this driver only support
memcpy interface. HW and driver doesn't support slave interface.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-03-11 07:42:30 +05:30