uvc_queue.h

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#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;
};

static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
{
    return queue->flags & UVC_QUEUE_STREAMING;
}

#endif /* __KERNEL__ */

#endif /* _UVC_QUEUE_H_ */