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author | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-09-08 10:16:27 -0300 |
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committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-09-09 10:05:32 -0300 |
commit | 4781646c1e13b23ed31eb12f7e314824d98ce066 (patch) | |
tree | e1a60c3f9d443a1bb145b7144590d66fbdcebd18 /include | |
parent | 82631b5bb268f670613db110177483ae3e85f913 (diff) | |
download | linux-4781646c1e13b23ed31eb12f7e314824d98ce066.tar.bz2 |
[media] v4l2-mem2mem.h: move descriptions from .c file
Several routines are somewhat documented at v4l2-mem2mem.c
file. Move what's there to the header file.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'include')
-rw-r--r-- | include/media/v4l2-mem2mem.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h index 5a9597dd1ee0..e5449a2c8475 100644 --- a/include/media/v4l2-mem2mem.h +++ b/include/media/v4l2-mem2mem.h @@ -94,13 +94,52 @@ struct v4l2_m2m_buffer { struct list_head list; }; +/** + * v4l2_m2m_get_curr_priv() - return driver private data for the currently + * running instance or NULL if no instance is running + */ void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev); +/** + * v4l2_m2m_get_vq() - return vb2_queue for the given type + */ struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx, enum v4l2_buf_type type); +/** + * v4l2_m2m_try_schedule() - check whether an instance is ready to be added to + * the pending job queue and add it if so. + * @m2m_ctx: m2m context assigned to the instance to be checked + * + * There are three basic requirements an instance has to meet to be able to run: + * 1) at least one source buffer has to be queued, + * 2) at least one destination buffer has to be queued, + * 3) streaming has to be on. + * + * If a queue is buffered (for example a decoder hardware ringbuffer that has + * to be drained before doing streamoff), allow scheduling without v4l2 buffers + * on that queue. + * + * There may also be additional, custom requirements. In such case the driver + * should supply a custom callback (job_ready in v4l2_m2m_ops) that should + * return 1 if the instance is ready. + * An example of the above could be an instance that requires more than one + * src/dst buffer per transaction. + */ void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx); +/** + * v4l2_m2m_job_finish() - inform the framework that a job has been finished + * and have it clean up + * + * Called by a driver to yield back the device after it has finished with it. + * 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. + */ void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev, struct v4l2_m2m_ctx *m2m_ctx); @@ -110,38 +149,114 @@ v4l2_m2m_buf_done(struct vb2_v4l2_buffer *buf, enum vb2_buffer_state state) vb2_buffer_done(&buf->vb2_buf, state); } +/** + * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer + */ int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct v4l2_requestbuffers *reqbufs); +/** + * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer + * + * See v4l2_m2m_mmap() documentation for details. + */ int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct v4l2_buffer *buf); +/** + * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on + * the type + */ int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct v4l2_buffer *buf); + +/** + * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on + * the type + */ int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct v4l2_buffer *buf); + +/** + * v4l2_m2m_prepare_buf() - prepare a source or destination buffer, depending on + * the type + */ int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct v4l2_buffer *buf); + +/** + * v4l2_m2m_create_bufs() - create a source or destination buffer, depending + * on the type + */ int v4l2_m2m_create_bufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct v4l2_create_buffers *create); +/** + * v4l2_m2m_expbuf() - export a source or destination buffer, depending on + * the type + */ int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct v4l2_exportbuffer *eb); +/** + * v4l2_m2m_streamon() - turn on streaming for a video queue + */ int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, enum v4l2_buf_type type); + +/** + * v4l2_m2m_streamoff() - turn off streaming for a video queue + */ int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, enum v4l2_buf_type type); +/** + * v4l2_m2m_poll() - poll replacement, for destination buffers only + * + * Call from the driver's poll() function. Will poll both queues. If a buffer + * is available to dequeue (with dqbuf) from the source queue, this will + * indicate that a non-blocking write can be performed, while read will be + * returned in case of the destination queue. + */ unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct poll_table_struct *wait); +/** + * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer + * + * Call from driver's mmap() function. Will handle mmap() for both queues + * seamlessly for videobuffer, which will receive normal per-queue offsets and + * proper videobuf queue pointers. The differentiation is made outside videobuf + * by adding a predefined offset to buffers from one of the queues and + * subtracting it before passing it back to videobuf. Only drivers (and + * thus applications) receive modified offsets. + */ int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, struct vm_area_struct *vma); +/** + * v4l2_m2m_init() - initialize per-driver m2m data + * + * Usually called from driver's probe() function. + */ struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops); + +/** + * v4l2_m2m_release() - cleans up and frees a m2m_dev structure + * + * Usually called from driver's remove() function. + */ void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev); +/** + * v4l2_m2m_ctx_init() - allocate and initialize a m2m context + * @priv - driver's instance private data + * @m2m_dev - a previously initialized m2m_dev struct + * @vq_init - a callback for queue type-specific initialization function to be + * used for initializing videobuf_queues + * + * Usually called from driver's open() function. + */ struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev, void *drv_priv, int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq)); @@ -158,8 +273,18 @@ static inline void v4l2_m2m_set_dst_buffered(struct v4l2_m2m_ctx *m2m_ctx, m2m_ctx->cap_q_ctx.buffered = buffered; } +/** + * v4l2_m2m_ctx_release() - release m2m context + * + * Usually called from driver's release() function. + */ void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx); +/** + * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list. + * + * Call from buf_queue(), videobuf_queue_ops callback. + */ void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_v4l2_buffer *vbuf); @@ -187,6 +312,9 @@ unsigned int v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx) return m2m_ctx->cap_q_ctx.num_rdy; } +/** + * v4l2_m2m_next_buf() - return next buffer from the list of ready buffers + */ void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx); /** @@ -233,6 +361,10 @@ struct vb2_queue *v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx *m2m_ctx) return &m2m_ctx->cap_q_ctx.q; } +/** + * v4l2_m2m_buf_remove() - take off a buffer from the list of ready buffers and + * return it + */ void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx); /** |