diff options
Diffstat (limited to 'include/media/v4l2-mem2mem.h')
| -rw-r--r-- | include/media/v4l2-mem2mem.h | 264 |
1 files changed, 246 insertions, 18 deletions
diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h index 5a9597dd1ee0..1b355344c804 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); @@ -55,29 +55,51 @@ struct v4l2_m2m_ops { 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: opaque pointer to the internal data to handle M2M context + * @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 */ @@ -85,22 +107,75 @@ 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; }; +/** + * v4l2_m2m_get_curr_priv() - return driver private data for the currently + * running instance or NULL if no instance is running + * + * @m2m_dev: opaque pointer to the internal data to handle M2M context + */ void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev); +/** + * v4l2_m2m_get_vq() - return vb2_queue for the given type + * + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @type: type of the V4L2 buffer, as defined by enum &v4l2_buf_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 given by struct &v4l2_m2m_ctx + * + * 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 + * + * @m2m_dev: opaque pointer to the internal data to handle M2M context + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * + * 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 &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); @@ -110,38 +185,165 @@ 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 + * + * @file: pointer to struct &file + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @reqbufs: pointer to struct &v4l2_requestbuffers + */ 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 + * + * @file: pointer to struct &file + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @buf: pointer to struct &v4l2_buffer + * + * 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 + * + * @file: pointer to struct &file + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @buf: pointer to struct &v4l2_buffer + */ 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 + * + * @file: pointer to struct &file + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @buf: pointer to struct &v4l2_buffer + */ 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 + * + * @file: pointer to struct &file + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @buf: pointer to struct &v4l2_buffer + */ 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 + * + * @file: pointer to struct &file + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @create: pointer to struct &v4l2_create_buffers + */ 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 + * + * @file: pointer to struct &file + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @eb: pointer to struct &v4l2_exportbuffer + */ 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 + * + * @file: pointer to struct &file + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @type: type of the V4L2 buffer, as defined by enum &v4l2_buf_type + */ 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 + * + * @file: pointer to struct &file + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @type: type of the V4L2 buffer, as defined by enum &v4l2_buf_type + */ 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 + * + * @file: pointer to struct &file + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @wait: pointer to struct &poll_table_struct + * + * 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 + * + * @file: pointer to struct &file + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @vma: pointer to struct &vm_area_struct + * + * 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 + * + * @m2m_ops: pointer to struct v4l2_m2m_ops + * + * 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); + +/** + * v4l2_m2m_release() - cleans up and frees a m2m_dev structure + * + * @m2m_dev: opaque pointer to the internal data to handle M2M context + * + * 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 + * + * @m2m_dev: opaque pointer to the internal data to handle M2M context + * @drv_priv: driver's instance private data + * @queue_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 +360,23 @@ 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 + * + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * + * 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. + * + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx + * @vbuf: pointer to struct &vb2_v4l2_buffer + * + * 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); @@ -167,7 +384,7 @@ void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, * v4l2_m2m_num_src_bufs_ready() - return the number of source buffers ready for * use * - * @m2m_ctx: pointer to struct v4l2_m2m_ctx + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx */ static inline unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx) @@ -176,10 +393,10 @@ unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx) } /** - * v4l2_m2m_num_src_bufs_ready() - return the number of destination buffers + * v4l2_m2m_num_dst_bufs_ready() - return the number of destination buffers * ready for use * - * @m2m_ctx: pointer to struct v4l2_m2m_ctx + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx */ static inline unsigned int v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx) @@ -187,13 +404,18 @@ 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 + * + * @q_ctx: pointer to struct @v4l2_m2m_queue_ctx + */ void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx); /** * v4l2_m2m_next_src_buf() - return next source buffer from the list of ready * buffers * - * @m2m_ctx: pointer to struct v4l2_m2m_ctx + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx */ static inline void *v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx) { @@ -204,7 +426,7 @@ static inline void *v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx) * v4l2_m2m_next_dst_buf() - return next destination buffer from the list of * ready buffers * - * @m2m_ctx: pointer to struct v4l2_m2m_ctx + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx */ static inline void *v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx) { @@ -214,7 +436,7 @@ static inline void *v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx) /** * v4l2_m2m_get_src_vq() - return vb2_queue for source buffers * - * @m2m_ctx: pointer to struct v4l2_m2m_ctx + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx */ static inline struct vb2_queue *v4l2_m2m_get_src_vq(struct v4l2_m2m_ctx *m2m_ctx) @@ -225,7 +447,7 @@ struct vb2_queue *v4l2_m2m_get_src_vq(struct v4l2_m2m_ctx *m2m_ctx) /** * v4l2_m2m_get_dst_vq() - return vb2_queue for destination buffers * - * @m2m_ctx: pointer to struct v4l2_m2m_ctx + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx */ static inline struct vb2_queue *v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx *m2m_ctx) @@ -233,13 +455,19 @@ 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 + * + * @q_ctx: pointer to struct @v4l2_m2m_queue_ctx + */ void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx); /** * v4l2_m2m_src_buf_remove() - take off a source buffer from the list of ready * buffers and return it * - * @m2m_ctx: pointer to struct v4l2_m2m_ctx + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx */ static inline void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx) { @@ -250,7 +478,7 @@ static inline void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx) * v4l2_m2m_dst_buf_remove() - take off a destination buffer from the list of * ready buffers and return it * - * @m2m_ctx: pointer to struct v4l2_m2m_ctx + * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx */ static inline void *v4l2_m2m_dst_buf_remove(struct v4l2_m2m_ctx *m2m_ctx) { |