From 5fa5edbe59a7ab8ab649268fcb578662dfb7ca99 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Thu, 8 Sep 2016 10:16:36 -0300 Subject: [media] v4l2-mem2mem.h: document the public structures Most structures here are not documented. Add a documentation for them. Signed-off-by: Mauro Carvalho Chehab --- include/media/v4l2-mem2mem.h | 67 +++++++++++++++++++++++++++++++++----------- 1 file changed, 51 insertions(+), 16 deletions(-) (limited to 'include/media/v4l2-mem2mem.h') diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h index 00410bd14772..cfa4f5e521a7 100644 --- a/include/media/v4l2-mem2mem.h +++ b/include/media/v4l2-mem2mem.h @@ -41,9 +41,9 @@ * This function does not have to (and will usually not) wait * until the device enters a state when it can be stopped. * @lock: optional. Define a driver's own lock callback, instead of using - * m2m_ctx->q_lock. + * &v4l2_m2m_ctx->q_lock. * @unlock: optional. Define a driver's own unlock callback, instead of - * using m2m_ctx->q_lock. + * using &v4l2_m2m_ctx->q_lock. */ struct v4l2_m2m_ops { void (*device_run)(void *priv); @@ -53,31 +53,59 @@ struct v4l2_m2m_ops { void (*unlock)(void *priv); }; +/** + * struct v4l2_m2m_dev - opaque struct used to represent a V4L2 M2M device. + * + * This structure is has the per-device context for a memory to memory + * device, and it is used internally at v4l2-mem2mem.c. + */ struct v4l2_m2m_dev; +/** + * struct v4l2_m2m_queue_ctx - represents a queue for buffers ready to be + * processed + * + * @q: pointer to struct &vb2_queue + * @rdy_queue: List of V4L2 mem-to-mem queues + * @rdy_spinlock: spin lock to protect the struct usage + * @num_rdy: number of buffers ready to be processed + * @buffered: is the queue buffered? + * + * Queue for buffers ready to be processed as soon as this + * instance receives access to the device. + */ + struct v4l2_m2m_queue_ctx { -/* private: internal use only */ struct vb2_queue q; - /* Queue for buffers ready to be processed as soon as this - * instance receives access to the device */ struct list_head rdy_queue; spinlock_t rdy_spinlock; u8 num_rdy; bool buffered; }; +/** + * struct v4l2_m2m_ctx - Memory to memory context structure + * + * @q_lock: struct &mutex lock + * @m2m_dev: pointer to struct &v4l2_m2m_dev + * @cap_q_ctx: Capture (output to memory) queue context + * @out_q_ctx: Output (input from memory) queue context + * @queue: List of memory to memory contexts + * @job_flags: Job queue flags, used internally by v4l2-mem2mem.c: + * %TRANS_QUEUED, %TRANS_RUNNING and %TRANS_ABORT. + * @finished: Wait queue used to signalize when a job queue finished. + * @priv: Instance private data + */ struct v4l2_m2m_ctx { /* optional cap/out vb2 queues lock */ struct mutex *q_lock; -/* private: internal use only */ + /* internal use only */ struct v4l2_m2m_dev *m2m_dev; - /* Capture (output to memory) queue context */ struct v4l2_m2m_queue_ctx cap_q_ctx; - /* Output (input from memory) queue context */ struct v4l2_m2m_queue_ctx out_q_ctx; /* For device job queue */ @@ -85,10 +113,15 @@ struct v4l2_m2m_ctx { unsigned long job_flags; wait_queue_head_t finished; - /* Instance private data */ void *priv; }; +/** + * struct v4l2_m2m_buffer - Memory to memory buffer + * + * @vb: pointer to struct &vb2_v4l2_buffer + * @list: list of m2m buffers + */ struct v4l2_m2m_buffer { struct vb2_v4l2_buffer vb; struct list_head list; @@ -145,9 +178,9 @@ void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx); * Should be called as soon as possible after reaching a state which allows * other instances to take control of the device. * - * This function has to be called only after device_run() callback has been - * called on the driver. To prevent recursion, it should not be called directly - * from the device_run() callback though. + * This function has to be called only after &v4l2_m2m_ops->device_run + * callback has been called on the driver. To prevent recursion, it should + * not be called directly from the &v4l2_m2m_ops->device_run callback though. */ void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev, struct v4l2_m2m_ctx *m2m_ctx); @@ -292,7 +325,9 @@ int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, * * @m2m_ops: pointer to struct v4l2_m2m_ops * - * Usually called from driver's probe() function. + * Usually called from driver's ``probe()`` function. + * + * Return: returns an opaque pointer to the internal data to handle M2M context */ struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops); @@ -301,7 +336,7 @@ struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops); * * @m2m_dev: pointer to struct &v4l2_m2m_dev * - * Usually called from driver's remove() function. + * Usually called from driver's ``remove()`` function. */ void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev); @@ -313,7 +348,7 @@ void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev); * @queue_init: a callback for queue type-specific initialization function * to be used for initializing videobuf_queues * - * Usually called from driver's open() function. + * Usually called from driver's ``open()`` function. */ struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev, void *drv_priv, @@ -346,7 +381,7 @@ void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx); * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx * @vbuf: pointer to struct &vb2_v4l2_buffer * - * Call from buf_queue(), videobuf_queue_ops callback. + * Call from videobuf_queue_ops->ops->buf_queue, videobuf_queue_ops callback. */ void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_v4l2_buffer *vbuf); -- cgit