/* * videobuf2-v4l2.h - V4L2 driver helper framework * * Copyright (C) 2010 Samsung Electronics * * Author: Pawel Osciak <pawel@osciak.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation. */ #ifndef _MEDIA_VIDEOBUF2_V4L2_H #define _MEDIA_VIDEOBUF2_V4L2_H #include <linux/videodev2.h> #include <media/videobuf2-core.h> #if VB2_MAX_FRAME != VIDEO_MAX_FRAME #error VB2_MAX_FRAME != VIDEO_MAX_FRAME #endif #if VB2_MAX_PLANES != VIDEO_MAX_PLANES #error VB2_MAX_PLANES != VIDEO_MAX_PLANES #endif /** * struct vb2_v4l2_buffer - video buffer information for v4l2 * * @vb2_buf: video buffer 2 * @flags: buffer informational flags * @field: enum v4l2_field; field order of the image in the buffer * @timecode: frame timecode * @sequence: sequence count of this frame * * Should contain enough information to be able to cover all the fields * of struct v4l2_buffer at videodev2.h */ struct vb2_v4l2_buffer { struct vb2_buffer vb2_buf; __u32 flags; __u32 field; struct v4l2_timecode timecode; __u32 sequence; }; /* * to_vb2_v4l2_buffer() - cast struct vb2_buffer * to struct vb2_v4l2_buffer * */ #define to_vb2_v4l2_buffer(vb) \ container_of(vb, struct vb2_v4l2_buffer, vb2_buf) int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b); /** * vb2_reqbufs() - Wrapper for vb2_core_reqbufs() that also verifies * the memory and type values. * * @q: videobuf2 queue * @req: struct passed from userspace to vidioc_reqbufs handler * in driver */ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req); /** * vb2_create_bufs() - Wrapper for vb2_core_create_bufs() that also verifies * the memory and type values. * * @q: videobuf2 queue * @create: creation parameters, passed from userspace to vidioc_create_bufs * handler in driver */ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create); /** * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel * * @q: videobuf2 queue * @b: buffer structure passed from userspace to vidioc_prepare_buf * handler in driver * * Should be called from vidioc_prepare_buf ioctl handler of a driver. * This function: * * #) verifies the passed buffer, * #) calls buf_prepare callback in the driver (if provided), in which * driver-specific buffer initialization can be performed. * * The return values from this function are intended to be directly returned * from vidioc_prepare_buf handler in driver. */ int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b); /** * vb2_qbuf() - Queue a buffer from userspace * @q: videobuf2 queue * @b: buffer structure passed from userspace to VIDIOC_QBUF() handler * in driver * * Should be called from VIDIOC_QBUF() ioctl handler of a driver. * * This function: * * #) verifies the passed buffer, * #) if necessary, calls buf_prepare callback in the driver (if provided), in * which driver-specific buffer initialization can be performed, * #) if streaming is on, queues the buffer in driver by the means of buf_queue * callback for processing. * * The return values from this function are intended to be directly returned * from VIDIOC_QBUF() handler in driver. */ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b); /** * vb2_expbuf() - Export a buffer as a file descriptor * @q: videobuf2 queue * @eb: export buffer structure passed from userspace to VIDIOC_EXPBUF() * handler in driver * * The return values from this function are intended to be directly returned * from VIDIOC_EXPBUF() handler in driver. */ int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb); /** * vb2_dqbuf() - Dequeue a buffer to the userspace * @q: videobuf2 queue * @b: buffer structure passed from userspace to VIDIOC_DQBUF() handler * in driver * @nonblocking: if true, this call will not sleep waiting for a buffer if no * buffers ready for dequeuing are present. Normally the driver * would be passing (file->f_flags & O_NONBLOCK) here * * Should be called from VIDIOC_DQBUF() ioctl handler of a driver. * * This function: * * #) verifies the passed buffer, * #) 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, * #) the buffer struct members are filled with relevant information for * the userspace. * * The return values from this function are intended to be directly returned * from VIDIOC_DQBUF() handler in driver. */ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking); /** * vb2_streamon - start streaming * @q: videobuf2 queue * @type: type argument passed from userspace to vidioc_streamon handler * * Should be called from vidioc_streamon handler of a driver. * * This function: * * 1) verifies current state * 2) passes any previously queued buffers to the driver and starts streaming * * The return values from this function are intended to be directly returned * from vidioc_streamon handler in the driver. */ int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type); /** * vb2_streamoff - stop streaming * @q: videobuf2 queue * @type: type argument passed from userspace to vidioc_streamoff handler * * Should be called from vidioc_streamoff handler of a driver. * * This function: * * #) verifies current state, * #) stop streaming and dequeues any queued buffers, including those previously * passed to the driver (after waiting for the driver to finish). * * This call can be used for pausing playback. * The return values from this function are intended to be directly returned * from vidioc_streamoff handler in the driver */ int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type); /** * vb2_queue_init() - initialize a videobuf2 queue * @q: videobuf2 queue; this structure should be allocated in driver * * The vb2_queue structure should be allocated by the driver. The driver is * responsible of clearing it's content and setting initial values for some * required entries before calling this function. * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer * to the struct vb2_queue description in include/media/videobuf2-core.h * for more information. */ int __must_check vb2_queue_init(struct vb2_queue *q); /** * vb2_queue_release() - stop streaming, release the queue and free memory * @q: videobuf2 queue * * This function stops streaming and performs necessary clean ups, including * freeing video buffer memory. The driver is responsible for freeing * the vb2_queue structure itself. */ void vb2_queue_release(struct vb2_queue *q); /** * vb2_poll() - implements poll userspace operation * @q: videobuf2 queue * @file: file argument passed to the poll file operation handler * @wait: wait argument passed to the poll file operation handler * * This function implements poll file operation handler for a driver. * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will * be informed that the file descriptor of a video device is available for * reading. * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor * will be reported as available for writing. * * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any * pending events. * * The return values from this function are intended to be directly returned * from poll handler in driver. */ unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait); /* * The following functions are not part of the vb2 core API, but are simple * helper functions that you can use in your struct v4l2_file_operations, * struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock * or video_device->lock is set, and they will set and test vb2_queue->owner * to check if the calling filehandle is permitted to do the queuing operation. */ /* struct v4l2_ioctl_ops helpers */ int vb2_ioctl_reqbufs(struct file *file, void *priv, struct v4l2_requestbuffers *p); int vb2_ioctl_create_bufs(struct file *file, void *priv, struct v4l2_create_buffers *p); int vb2_ioctl_prepare_buf(struct file *file, void *priv, struct v4l2_buffer *p); int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p); int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p); int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p); int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i); int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i); int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p); /* struct v4l2_file_operations helpers */ int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma); int vb2_fop_release(struct file *file); int _vb2_fop_release(struct file *file, struct mutex *lock); ssize_t vb2_fop_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos); ssize_t vb2_fop_read(struct file *file, char __user *buf, size_t count, loff_t *ppos); unsigned int vb2_fop_poll(struct file *file, poll_table *wait); #ifndef CONFIG_MMU unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags); #endif /** * vb2_ops_wait_prepare - helper function to lock a struct &vb2_queue * * @vq: pointer to struct vb2_queue * * ..note:: only use if vq->lock is non-NULL. */ void vb2_ops_wait_prepare(struct vb2_queue *vq); /** * vb2_ops_wait_finish - helper function to unlock a struct &vb2_queue * * @vq: pointer to struct vb2_queue * * ..note:: only use if vq->lock is non-NULL. */ void vb2_ops_wait_finish(struct vb2_queue *vq); #endif /* _MEDIA_VIDEOBUF2_V4L2_H */