diff options
Diffstat (limited to 'include/media/videobuf2-core.h')
| -rw-r--r-- | include/media/videobuf2-core.h | 143 |
1 files changed, 85 insertions, 58 deletions
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index 65eeca8..9a144f2 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -49,13 +49,13 @@ struct vb2_threadio_data; * @alloc: allocate video memory and, optionally, allocator private data, * return ERR_PTR() on failure or a pointer to allocator private, * per-buffer data on success; the returned private structure - * will then be passed as buf_priv argument to other ops in this + * will then be passed as @buf_priv argument to other ops in this * structure. Additional gfp_flags to use when allocating the * are also passed to this operation. These flags are from the * gfp_flags field of vb2_queue. * @put: inform the allocator that the buffer will no longer be used; * usually will result in the allocator freeing the buffer (if - * no other users of this buffer are present); the buf_priv + * no other users of this buffer are present); the @buf_priv * argument is the allocator private per-buffer structure * previously returned from the alloc callback. * @get_dmabuf: acquire userspace memory for a hardware operation; used for @@ -65,7 +65,7 @@ struct vb2_threadio_data; * videobuf layer when queuing a video buffer of USERPTR type; * should return an allocator private per-buffer structure * associated with the buffer on success, ERR_PTR() on failure; - * the returned private structure will then be passed as buf_priv + * the returned private structure will then be passed as @buf_priv * argument to other ops in this structure. * @put_userptr: inform the allocator that a USERPTR buffer will no longer * be used. @@ -75,7 +75,7 @@ struct vb2_threadio_data; * allocator private per-buffer structure on success; * this needs to be used for further accesses to the buffer. * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF - * buffer is no longer used; the buf_priv argument is the + * buffer is no longer used; the @buf_priv argument is the * allocator private per-buffer structure previously returned * from the attach_dmabuf callback. * @map_dmabuf: request for access to the dmabuf from allocator; the allocator @@ -109,11 +109,13 @@ struct vb2_threadio_data; * * #) Required ops for read/write access types: alloc, put, num_users, vaddr. * - * #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, map_dmabuf, unmap_dmabuf. + * #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, + * map_dmabuf, unmap_dmabuf. */ struct vb2_mem_ops { void *(*alloc)(struct device *dev, unsigned long attrs, - unsigned long size, enum dma_data_direction dma_dir, + unsigned long size, + enum dma_data_direction dma_dir, gfp_t gfp_flags); void (*put)(void *buf_priv); struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags); @@ -126,7 +128,8 @@ struct vb2_mem_ops { void (*prepare)(void *buf_priv); void (*finish)(void *buf_priv); - void *(*attach_dmabuf)(struct device *dev, struct dma_buf *dbuf, + void *(*attach_dmabuf)(struct device *dev, + struct dma_buf *dbuf, unsigned long size, enum dma_data_direction dma_dir); void (*detach_dmabuf)(void *buf_priv); @@ -291,7 +294,7 @@ struct vb2_buffer { /** * struct vb2_ops - driver-specific callbacks * - * @queue_setup: called from %VIDIOC_REQBUFS and %VIDIOC_CREATE_BUFS + * @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS() * handlers before memory allocation. It can be called * twice: if the original number of requested buffers * could not be allocated, then it will be called a @@ -302,11 +305,11 @@ struct vb2_buffer { * buffer in \*num_planes, the size of each plane should be * set in the sizes\[\] array and optional per-plane * allocator specific device in the alloc_devs\[\] array. - * When called from %VIDIOC_REQBUFS, \*num_planes == 0, the - * driver has to use the currently configured format to + * When called from VIDIOC_REQBUFS,() \*num_planes == 0, + * the driver has to use the currently configured format to * determine the plane sizes and \*num_buffers is the total * number of buffers that are being allocated. When called - * from %VIDIOC_CREATE_BUFS, \*num_planes != 0 and it + * from VIDIOC_CREATE_BUFS,() \*num_planes != 0 and it * describes the requested number of planes and sizes\[\] * contains the requested plane sizes. If either * \*num_planes or the requested sizes are invalid callback @@ -325,11 +328,11 @@ struct vb2_buffer { * initialization failure (return != 0) will prevent * queue setup from completing successfully; optional. * @buf_prepare: called every time the buffer is queued from userspace - * and from the %VIDIOC_PREPARE_BUF ioctl; drivers may + * and from the VIDIOC_PREPARE_BUF() ioctl; drivers may * perform any initialization required before each * hardware operation in this callback; drivers can * access/modify the buffer here as it is still synced for - * the CPU; drivers that support %VIDIOC_CREATE_BUFS must + * the CPU; drivers that support VIDIOC_CREATE_BUFS() must * also validate the buffer size; if an error is returned, * the buffer will not be queued in driver; optional. * @buf_finish: called before every dequeue of the buffer back to @@ -353,24 +356,25 @@ struct vb2_buffer { * driver can return an error if hardware fails, in that * case all buffers that have been already given by * the @buf_queue callback are to be returned by the driver - * by calling @vb2_buffer_done\(%VB2_BUF_STATE_QUEUED\). + * by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED. * If you need a minimum number of buffers before you can * start streaming, then set @min_buffers_needed in the * vb2_queue structure. If that is non-zero then - * start_streaming won't be called until at least that + * @start_streaming won't be called until at least that * many buffers have been queued up by userspace. * @stop_streaming: called when 'streaming' state must be disabled; driver * should stop any DMA transactions or wait until they * finish and give back all buffers it got from &buf_queue - * callback by calling @vb2_buffer_done\(\) with either + * callback by calling vb2_buffer_done() with either * %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use * vb2_wait_for_all_buffers() function * @buf_queue: passes buffer vb to the driver; driver may start * hardware operation on this buffer; driver should give * the buffer back by calling vb2_buffer_done() function; - * it is allways called after calling %VIDIOC_STREAMON ioctl; - * might be called before start_streaming callback if user - * pre-queued buffers before calling %VIDIOC_STREAMON. + * it is allways called after calling VIDIOC_STREAMON() + * ioctl; might be called before @start_streaming callback + * if user pre-queued buffers before calling + * VIDIOC_STREAMON(). */ struct vb2_ops { int (*queue_setup)(struct vb2_queue *q, @@ -418,7 +422,7 @@ struct vb2_buf_ops { * * @type: private buffer type whose content is defined by the vb2-core * caller. For example, for V4L2, it should match - * the V4L2_BUF_TYPE_* in include/uapi/linux/videodev2.h + * the types defined on enum &v4l2_buf_type * @io_modes: supported io methods (see vb2_io_modes enum) * @dev: device to use for the default allocation context if the driver * doesn't fill in the @alloc_devs array. @@ -453,12 +457,12 @@ struct vb2_buf_ops { * Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32 * to force the buffer allocation to a specific memory zone. * @min_buffers_needed: the minimum number of buffers needed before - * start_streaming() can be called. Used when a DMA engine + * @start_streaming can be called. Used when a DMA engine * cannot be started unless at least this number of buffers * have been queued into the driver. */ /* - * Private elements (won't appear at the DocBook): + * Private elements (won't appear at the uAPI book): * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped * @memory: current memory type used * @bufs: videobuf buffer structures @@ -471,7 +475,7 @@ struct vb2_buf_ops { * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued * @alloc_devs: memory type/allocator-specific per-plane device * @streaming: current streaming state - * @start_streaming_called: start_streaming() was called successfully and we + * @start_streaming_called: @start_streaming was called successfully and we * started streaming. * @error: a fatal error occurred on the queue * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for @@ -576,17 +580,18 @@ void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no); /** * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished * @vb: vb2_buffer returned from the driver - * @state: either %VB2_BUF_STATE_DONE if the operation finished successfully, - * %VB2_BUF_STATE_ERROR if the operation finished with an error or - * %VB2_BUF_STATE_QUEUED if the driver wants to requeue buffers. - * If start_streaming fails then it should return buffers with state - * %VB2_BUF_STATE_QUEUED to put them back into the queue. + * @state: either %VB2_BUF_STATE_DONE if the operation finished + * successfully, %VB2_BUF_STATE_ERROR if the operation finished + * with an error or %VB2_BUF_STATE_QUEUED if the driver wants to + * requeue buffers. If start_streaming fails then it should return + * buffers with state %VB2_BUF_STATE_QUEUED to put them back into + * the queue. * * This function should be called by the driver after a hardware operation on * a buffer is finished and the buffer may be returned to userspace. The driver * cannot use this buffer anymore until it is queued back to it by videobuf - * by the means of buf_queue callback. Only buffers previously queued to the - * driver by buf_queue can be passed to this function. + * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued + * to the driver by &vb2_ops->buf_queue can be passed to this function. * * While streaming a buffer can only be returned in state DONE or ERROR. * The start_streaming op can also return them in case the DMA engine cannot @@ -614,9 +619,9 @@ void vb2_discard_done(struct vb2_queue *q); * @q: videobuf2 queue * * This function will wait until all buffers that have been given to the driver - * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call - * wait_prepare, wait_finish pair. It is intended to be called with all locks - * taken, for example from stop_streaming() callback. + * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It + * doesn't call wait_prepare()/wait_finish() pair. It is intended to be called + * with all locks taken, for example from &vb2_ops->stop_streaming callback. */ int vb2_wait_for_all_buffers(struct vb2_queue *q); @@ -639,14 +644,16 @@ void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb); * @count: requested buffer count * * Should be called from vidioc_reqbufs ioctl handler of a driver. + * * This function: - * 1) verifies streaming parameters passed from the userspace, - * 2) sets up the queue, - * 3) negotiates number of buffers and planes per buffer with the driver + * + * #) verifies streaming parameters passed from the userspace, + * #) sets up the queue, + * #) negotiates number of buffers and planes per buffer with the driver * to be used during streaming, - * 4) allocates internal buffer structures (struct vb2_buffer), according to + * #) allocates internal buffer structures (struct vb2_buffer), according to * the agreed parameters, - * 5) for MMAP memory type, allocates actual video memory, using the + * #) for MMAP memory type, allocates actual video memory, using the * memory handling/allocation routines provided during queue initialization * * If req->count is 0, all the memory will be freed instead. @@ -664,20 +671,22 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, * @q: videobuf2 queue * @memory: memory type * @count: requested buffer count - * @parg: parameter passed to device driver + * @requested_planes: number of planes requested + * @requested_sizes: array with the size of the planes * - * Should be called from vidioc_create_bufs ioctl handler of a driver. + * Should be called from VIDIOC_CREATE_BUFS() ioctl handler of a driver. * This function: - * 1) verifies parameter sanity - * 2) calls the .queue_setup() queue operation - * 3) performs any necessary memory allocations * - * The return values from this function are intended to be directly returned - * from vidioc_create_bufs handler in driver. + * #) verifies parameter sanity + * #) calls the .queue_setup() queue operation + * #) performs any necessary memory allocations + * + * Return: the return values from this function are intended to be directly + * returned from VIDIOC_CREATE_BUFS() handler in driver. */ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, - unsigned int *count, unsigned requested_planes, - const unsigned int requested_sizes[]); + unsigned int *count, unsigned int requested_planes, + const unsigned int requested_sizes[]); /** * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace @@ -699,6 +708,7 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb); /** * vb2_core_qbuf() - Queue a buffer from userspace + * * @q: videobuf2 queue * @index: id number of the buffer * @pb: buffer structure passed from userspace to vidioc_qbuf handler @@ -706,11 +716,13 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb); * * Should be called from vidioc_qbuf ioctl handler of a driver. * The passed buffer should have been verified. + * * This function: - * 1) if necessary, calls buf_prepare callback in the driver (if provided), in + * + * #) if necessary, calls buf_prepare callback in the driver (if provided), in * which driver-specific buffer initialization can be performed, - * 2) if streaming is on, queues the buffer in driver by the means of buf_queue - * callback for processing. + * #) if streaming is on, queues the buffer in driver by the means of + * &vb2_ops->buf_queue callback for processing. * * The return values from this function are intended to be directly returned * from vidioc_qbuf handler in driver. @@ -729,11 +741,13 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb); * * Should be called from vidioc_dqbuf ioctl handler of a driver. * The passed buffer should have been verified. + * * This function: - * 1) calls buf_finish callback in the driver (if provided), in which + * + * #) calls buf_finish callback in the driver (if provided), in which * driver can perform any additional operations that may be required before * returning the buffer to userspace, such as cache sync, - * 2) the buffer struct members are filled with relevant information for + * #) the buffer struct members are filled with relevant information for * the userspace. * * The return values from this function are intended to be directly returned @@ -819,6 +833,7 @@ void vb2_queue_error(struct vb2_queue *q); * from the mmap handler in driver. */ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma); + #ifndef CONFIG_MMU unsigned long vb2_get_unmapped_area(struct vb2_queue *q, unsigned long addr, @@ -844,14 +859,18 @@ unsigned long vb2_get_unmapped_area(struct vb2_queue *q, * from poll handler in driver. */ unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file, - poll_table *wait); + poll_table *wait); + size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, loff_t *ppos, int nonblock); size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count, loff_t *ppos, int nonblock); -/* - * vb2_thread_fnc - callback function for use with vb2_thread +/** + * typedef vb2_thread_fnc - callback function for use with vb2_thread + * + * @vb: pointer to struct &vb2_buffer + * @priv: pointer to a private pointer * * This is called whenever a buffer is dequeued in the thread. */ @@ -867,9 +886,11 @@ typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv); * This starts a thread that will queue and dequeue until an error occurs * or @vb2_thread_stop is called. * - * This function should not be used for anything else but the videobuf2-dvb - * support. If you think you have another good use-case for this, then please - * contact the linux-media mailinglist first. + * .. attention:: + * + * This function should not be used for anything else but the videobuf2-dvb + * support. If you think you have another good use-case for this, then please + * contact the linux-media mailing list first. */ int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv, const char *thread_name); @@ -1000,6 +1021,12 @@ bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb); /** * vb2_verify_memory_type() - Check whether the memory type and buffer type * passed to a buffer operation are compatible with the queue. + * + * @q: videobuf queue + * @memory: memory model, as defined by enum &vb2_memory. + * @type: private buffer type whose content is defined by the vb2-core + * caller. For example, for V4L2, it should match + * the types defined on enum &v4l2_buf_type */ int vb2_verify_memory_type(struct vb2_queue *q, enum vb2_memory memory, unsigned int type); |
