From 466749f13e33d892cf9263d7efbc0ea713c23ed7 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Mon, 10 Apr 2017 12:27:01 +0200 Subject: [PATCH] gpu: host1x: Flesh out kerneldoc Improve kerneldoc for the public parts of the host1x infrastructure in preparation for adding driver-specific part to the GPU documentation. Acked-by: Daniel Vetter Signed-off-by: Thierry Reding --- drivers/gpu/host1x/bus.c | 75 ++++++++++++++++++++++++++++++++++ drivers/gpu/host1x/syncpt.c | 81 ++++++++++++++++++++++++++++++++----- include/linux/host1x.h | 25 ++++++++++++ 3 files changed, 170 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c index 561831e1ae2c..a048e3ac523d 100644 --- a/drivers/gpu/host1x/bus.c +++ b/drivers/gpu/host1x/bus.c @@ -40,6 +40,9 @@ struct host1x_subdev { /** * host1x_subdev_add() - add a new subdevice with an associated device node + * @device: host1x device to add the subdevice to + * @driver: host1x driver + * @np: device node */ static int host1x_subdev_add(struct host1x_device *device, struct device_node *np) @@ -62,6 +65,7 @@ static int host1x_subdev_add(struct host1x_device *device, /** * host1x_subdev_del() - remove subdevice + * @subdev: subdevice to remove */ static void host1x_subdev_del(struct host1x_subdev *subdev) { @@ -72,6 +76,8 @@ static void host1x_subdev_del(struct host1x_subdev *subdev) /** * host1x_device_parse_dt() - scan device tree and add matching subdevices + * @device: host1x logical device + * @driver: host1x driver */ static int host1x_device_parse_dt(struct host1x_device *device, struct host1x_driver *driver) @@ -166,6 +172,16 @@ static void host1x_subdev_unregister(struct host1x_device *device, mutex_unlock(&device->subdevs_lock); } +/** + * host1x_device_init() - initialize a host1x logical device + * @device: host1x logical device + * + * The driver for the host1x logical device can call this during execution of + * its &host1x_driver.probe implementation to initialize each of its clients. + * The client drivers access the subsystem specific driver data using the + * &host1x_client.parent field and driver data associated with it (usually by + * calling dev_get_drvdata()). + */ int host1x_device_init(struct host1x_device *device) { struct host1x_client *client; @@ -192,6 +208,15 @@ int host1x_device_init(struct host1x_device *device) } EXPORT_SYMBOL(host1x_device_init); +/** + * host1x_device_exit() - uninitialize host1x logical device + * @device: host1x logical device + * + * When the driver for a host1x logical device is unloaded, it can call this + * function to tear down each of its clients. Typically this is done after a + * subsystem-specific data structure is removed and the functionality can no + * longer be used. + */ int host1x_device_exit(struct host1x_device *device) { struct host1x_client *client; @@ -446,6 +471,14 @@ static void host1x_detach_driver(struct host1x *host1x, mutex_unlock(&host1x->devices_lock); } +/** + * host1x_register() - register a host1x controller + * @host1x: host1x controller + * + * The host1x controller driver uses this to register a host1x controller with + * the infrastructure. Note that all Tegra SoC generations have only ever come + * with a single host1x instance, so this function is somewhat academic. + */ int host1x_register(struct host1x *host1x) { struct host1x_driver *driver; @@ -464,6 +497,13 @@ int host1x_register(struct host1x *host1x) return 0; } +/** + * host1x_unregister() - unregister a host1x controller + * @host1x: host1x controller + * + * The host1x controller driver uses this to remove a host1x controller from + * the infrastructure. + */ int host1x_unregister(struct host1x *host1x) { struct host1x_driver *driver; @@ -513,6 +553,16 @@ static void host1x_device_shutdown(struct device *dev) driver->shutdown(device); } +/** + * host1x_driver_register_full() - register a host1x driver + * @driver: host1x driver + * @owner: owner module + * + * Drivers for host1x logical devices call this function to register a driver + * with the infrastructure. Note that since these drive logical devices, the + * registration of the driver actually triggers tho logical device creation. + * A logical device will be created for each host1x instance. + */ int host1x_driver_register_full(struct host1x_driver *driver, struct module *owner) { @@ -541,6 +591,13 @@ int host1x_driver_register_full(struct host1x_driver *driver, } EXPORT_SYMBOL(host1x_driver_register_full); +/** + * host1x_driver_unregister() - unregister a host1x driver + * @driver: host1x driver + * + * Unbinds the driver from each of the host1x logical devices that it is + * bound to, effectively removing the subsystem devices that they represent. + */ void host1x_driver_unregister(struct host1x_driver *driver) { driver_unregister(&driver->driver); @@ -551,6 +608,17 @@ void host1x_driver_unregister(struct host1x_driver *driver) } EXPORT_SYMBOL(host1x_driver_unregister); +/** + * host1x_client_register() - register a host1x client + * @client: host1x client + * + * Registers a host1x client with each host1x controller instance. Note that + * each client will only match their parent host1x controller and will only be + * associated with that instance. Once all clients have been registered with + * their parent host1x controller, the infrastructure will set up the logical + * device and call host1x_device_init(), which will in turn call each client's + * &host1x_client_ops.init implementation. + */ int host1x_client_register(struct host1x_client *client) { struct host1x *host1x; @@ -576,6 +644,13 @@ int host1x_client_register(struct host1x_client *client) } EXPORT_SYMBOL(host1x_client_register); +/** + * host1x_client_unregister() - unregister a host1x client + * @client: host1x client + * + * Removes a host1x client from its host1x controller instance. If a logical + * device has already been initialized, it will be torn down. + */ int host1x_client_unregister(struct host1x_client *client) { struct host1x_client *c; diff --git a/drivers/gpu/host1x/syncpt.c b/drivers/gpu/host1x/syncpt.c index 0ac026cdc30c..048ac9e344ce 100644 --- a/drivers/gpu/host1x/syncpt.c +++ b/drivers/gpu/host1x/syncpt.c @@ -99,14 +99,24 @@ static struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host, return NULL; } +/** + * host1x_syncpt_id() - retrieve syncpoint ID + * @sp: host1x syncpoint + * + * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is + * often used as a value to program into registers that control how hardware + * blocks interact with syncpoints. + */ u32 host1x_syncpt_id(struct host1x_syncpt *sp) { return sp->id; } EXPORT_SYMBOL(host1x_syncpt_id); -/* - * Updates the value sent to hardware. +/** + * host1x_syncpt_incr_max() - update the value sent to hardware + * @sp: host1x syncpoint + * @incrs: number of increments */ u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs) { @@ -175,8 +185,9 @@ u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp) return sp->base_val; } -/* - * Increment syncpoint value from cpu, updating cache +/** + * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache + * @sp: host1x syncpoint */ int host1x_syncpt_incr(struct host1x_syncpt *sp) { @@ -195,8 +206,12 @@ static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh) return host1x_syncpt_is_expired(sp, thresh); } -/* - * Main entrypoint for syncpoint value waits. +/** + * host1x_syncpt_wait() - wait for a syncpoint to reach a given value + * @sp: host1x syncpoint + * @thresh: threshold + * @timeout: maximum time to wait for the syncpoint to reach the given value + * @value: return location for the syncpoint value */ int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout, u32 *value) @@ -402,6 +417,16 @@ int host1x_syncpt_init(struct host1x *host) return 0; } +/** + * host1x_syncpt_request() - request a syncpoint + * @dev: device requesting the syncpoint + * @flags: flags + * + * host1x client drivers can use this function to allocate a syncpoint for + * subsequent use. A syncpoint returned by this function will be reserved for + * use by the client exclusively. When no longer using a syncpoint, a host1x + * client driver needs to release it using host1x_syncpt_free(). + */ struct host1x_syncpt *host1x_syncpt_request(struct device *dev, unsigned long flags) { @@ -411,6 +436,16 @@ struct host1x_syncpt *host1x_syncpt_request(struct device *dev, } EXPORT_SYMBOL(host1x_syncpt_request); +/** + * host1x_syncpt_free() - free a requested syncpoint + * @sp: host1x syncpoint + * + * Release a syncpoint previously allocated using host1x_syncpt_request(). A + * host1x client driver should call this when the syncpoint is no longer in + * use. Note that client drivers must ensure that the syncpoint doesn't remain + * under the control of hardware after calling this function, otherwise two + * clients may end up trying to access the same syncpoint concurrently. + */ void host1x_syncpt_free(struct host1x_syncpt *sp) { if (!sp) @@ -438,9 +473,12 @@ void host1x_syncpt_deinit(struct host1x *host) kfree(sp->name); } -/* - * Read max. It indicates how many operations there are in queue, either in - * channel or in a software thread. +/** + * host1x_syncpt_read_max() - read maximum syncpoint value + * @sp: host1x syncpoint + * + * The maximum syncpoint value indicates how many operations there are in + * queue, either in channel or in a software thread. */ u32 host1x_syncpt_read_max(struct host1x_syncpt *sp) { @@ -450,8 +488,12 @@ u32 host1x_syncpt_read_max(struct host1x_syncpt *sp) } EXPORT_SYMBOL(host1x_syncpt_read_max); -/* - * Read min, which is a shadow of the current sync point value in hardware. +/** + * host1x_syncpt_read_min() - read minimum syncpoint value + * @sp: host1x syncpoint + * + * The minimum syncpoint value is a shadow of the current sync point value in + * hardware. */ u32 host1x_syncpt_read_min(struct host1x_syncpt *sp) { @@ -461,6 +503,10 @@ u32 host1x_syncpt_read_min(struct host1x_syncpt *sp) } EXPORT_SYMBOL(host1x_syncpt_read_min); +/** + * host1x_syncpt_read() - read the current syncpoint value + * @sp: host1x syncpoint + */ u32 host1x_syncpt_read(struct host1x_syncpt *sp) { return host1x_syncpt_load(sp); @@ -482,6 +528,11 @@ unsigned int host1x_syncpt_nb_mlocks(struct host1x *host) return host->info->nb_mlocks; } +/** + * host1x_syncpt_get() - obtain a syncpoint by ID + * @host: host1x controller + * @id: syncpoint ID + */ struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id) { if (id >= host->info->nb_pts) @@ -491,12 +542,20 @@ struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id) } EXPORT_SYMBOL(host1x_syncpt_get); +/** + * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint + * @sp: host1x syncpoint + */ struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp) { return sp ? sp->base : NULL; } EXPORT_SYMBOL(host1x_syncpt_get_base); +/** + * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base + * @base: host1x syncpoint wait base + */ u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base) { return base->id; diff --git a/include/linux/host1x.h b/include/linux/host1x.h index 3d04aa1dc83e..840a8ad627b2 100644 --- a/include/linux/host1x.h +++ b/include/linux/host1x.h @@ -32,11 +32,27 @@ enum host1x_class { struct host1x_client; +/** + * struct host1x_client_ops - host1x client operations + * @init: host1x client initialization code + * @exit: host1x client tear down code + */ struct host1x_client_ops { int (*init)(struct host1x_client *client); int (*exit)(struct host1x_client *client); }; +/** + * struct host1x_client - host1x client structure + * @list: list node for the host1x client + * @parent: pointer to struct device representing the host1x controller + * @dev: pointer to struct device backing this host1x client + * @ops: host1x client operations + * @class: host1x class represented by this client + * @channel: host1x channel associated with this client + * @syncpts: array of syncpoints requested for this client + * @num_syncpts: number of syncpoints requested for this client + */ struct host1x_client { struct list_head list; struct device *parent; @@ -251,6 +267,15 @@ void host1x_job_unpin(struct host1x_job *job); struct host1x_device; +/** + * struct host1x_driver - host1x logical device driver + * @driver: core driver + * @subdevs: table of OF device IDs matching subdevices for this driver + * @list: list node for the driver + * @probe: called when the host1x logical device is probed + * @remove: called when the host1x logical device is removed + * @shutdown: called when the host1x logical device is shut down + */ struct host1x_driver { struct device_driver driver;