linux/drivers/usb/gadget/uvc_queue.h
Laurent Pinchart cdda479f15 USB gadget: video class function driver
This USB video class function driver implements a video capture device from the
host's point of view. It creates a V4L2 output device on the gadget's side to
transfer data from a userspace application over USB.

The UVC-specific descriptors are passed by the gadget driver to the UVC
function driver, making them completely configurable without any modification
to the function's driver code.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-20 13:21:41 -07:00

90 lines
2.5 KiB
C

#ifndef _UVC_QUEUE_H_
#define _UVC_QUEUE_H_
#ifdef __KERNEL__
#include <linux/kernel.h>
#include <linux/poll.h>
#include <linux/videodev2.h>
/* Maximum frame size in bytes, for sanity checking. */
#define UVC_MAX_FRAME_SIZE (16*1024*1024)
/* Maximum number of video buffers. */
#define UVC_MAX_VIDEO_BUFFERS 32
/* ------------------------------------------------------------------------
* Structures.
*/
enum uvc_buffer_state {
UVC_BUF_STATE_IDLE = 0,
UVC_BUF_STATE_QUEUED = 1,
UVC_BUF_STATE_ACTIVE = 2,
UVC_BUF_STATE_DONE = 3,
UVC_BUF_STATE_ERROR = 4,
};
struct uvc_buffer {
unsigned long vma_use_count;
struct list_head stream;
/* Touched by interrupt handler. */
struct v4l2_buffer buf;
struct list_head queue;
wait_queue_head_t wait;
enum uvc_buffer_state state;
};
#define UVC_QUEUE_STREAMING (1 << 0)
#define UVC_QUEUE_DISCONNECTED (1 << 1)
#define UVC_QUEUE_DROP_INCOMPLETE (1 << 2)
#define UVC_QUEUE_PAUSED (1 << 3)
struct uvc_video_queue {
enum v4l2_buf_type type;
void *mem;
unsigned int flags;
__u32 sequence;
unsigned int count;
unsigned int buf_size;
unsigned int buf_used;
struct uvc_buffer buffer[UVC_MAX_VIDEO_BUFFERS];
struct mutex mutex; /* protects buffers and mainqueue */
spinlock_t irqlock; /* protects irqqueue */
struct list_head mainqueue;
struct list_head irqqueue;
};
extern void uvc_queue_init(struct uvc_video_queue *queue,
enum v4l2_buf_type type);
extern int uvc_alloc_buffers(struct uvc_video_queue *queue,
unsigned int nbuffers, unsigned int buflength);
extern int uvc_free_buffers(struct uvc_video_queue *queue);
extern int uvc_query_buffer(struct uvc_video_queue *queue,
struct v4l2_buffer *v4l2_buf);
extern int uvc_queue_buffer(struct uvc_video_queue *queue,
struct v4l2_buffer *v4l2_buf);
extern int uvc_dequeue_buffer(struct uvc_video_queue *queue,
struct v4l2_buffer *v4l2_buf, int nonblocking);
extern int uvc_queue_enable(struct uvc_video_queue *queue, int enable);
extern void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect);
extern struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
struct uvc_buffer *buf);
extern unsigned int uvc_queue_poll(struct uvc_video_queue *queue,
struct file *file, poll_table *wait);
extern int uvc_queue_mmap(struct uvc_video_queue *queue,
struct vm_area_struct *vma);
static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
{
return queue->flags & UVC_QUEUE_STREAMING;
}
extern struct uvc_buffer *uvc_queue_head(struct uvc_video_queue *queue);
#endif /* __KERNEL__ */
#endif /* _UVC_QUEUE_H_ */