* 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);
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 */
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);
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));
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);
* 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)
}
/**
- * 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)
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)
{
* 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)
{
/**
* 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)
/**
* 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)
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)
{
* 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)
{
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