| /* |
| * uvc_queue.c -- USB Video Class driver - Buffers management |
| * |
| * Copyright (C) 2005-2010 |
| * Laurent Pinchart (laurent.pinchart@ideasonboard.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; either version 2 of the License, or |
| * (at your option) any later version. |
| */ |
| |
| #include <linux/atomic.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/list.h> |
| #include <linux/module.h> |
| #include <linux/usb.h> |
| #include <linux/videodev2.h> |
| #include <linux/vmalloc.h> |
| #include <linux/wait.h> |
| |
| #include <media/v4l2-common.h> |
| #include <media/videobuf2-vmalloc.h> |
| |
| #include "uvc.h" |
| |
| /* ------------------------------------------------------------------------ |
| * Video buffers queue management. |
| * |
| * Video queues is initialized by uvcg_queue_init(). The function performs |
| * basic initialization of the uvc_video_queue struct and never fails. |
| * |
| * Video buffers are managed by videobuf2. The driver uses a mutex to protect |
| * the videobuf2 queue operations by serializing calls to videobuf2 and a |
| * spinlock to protect the IRQ queue that holds the buffers to be processed by |
| * the driver. |
| */ |
| |
| /* ----------------------------------------------------------------------------- |
| * videobuf2 queue operations |
| */ |
| |
| static int uvc_queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt, |
| unsigned int *nbuffers, unsigned int *nplanes, |
| unsigned int sizes[], void *alloc_ctxs[]) |
| { |
| struct uvc_video_queue *queue = vb2_get_drv_priv(vq); |
| struct uvc_video *video = container_of(queue, struct uvc_video, queue); |
| |
| if (*nbuffers > UVC_MAX_VIDEO_BUFFERS) |
| *nbuffers = UVC_MAX_VIDEO_BUFFERS; |
| |
| *nplanes = 1; |
| |
| sizes[0] = video->imagesize; |
| |
| return 0; |
| } |
| |
| static int uvc_buffer_prepare(struct vb2_buffer *vb) |
| { |
| struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue); |
| struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf); |
| |
| if (vb->v4l2_buf.type == V4L2_BUF_TYPE_VIDEO_OUTPUT && |
| vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) { |
| uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n"); |
| return -EINVAL; |
| } |
| |
| if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED)) |
| return -ENODEV; |
| |
| buf->state = UVC_BUF_STATE_QUEUED; |
| buf->mem = vb2_plane_vaddr(vb, 0); |
| buf->length = vb2_plane_size(vb, 0); |
| if (vb->v4l2_buf.type == V4L2_BUF_TYPE_VIDEO_CAPTURE) |
| buf->bytesused = 0; |
| else |
| buf->bytesused = vb2_get_plane_payload(vb, 0); |
| |
| return 0; |
| } |
| |
| static void uvc_buffer_queue(struct vb2_buffer *vb) |
| { |
| struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue); |
| struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf); |
| unsigned long flags; |
| |
| spin_lock_irqsave(&queue->irqlock, flags); |
| |
| if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) { |
| list_add_tail(&buf->queue, &queue->irqqueue); |
| } else { |
| /* If the device is disconnected return the buffer to userspace |
| * directly. The next QBUF call will fail with -ENODEV. |
| */ |
| buf->state = UVC_BUF_STATE_ERROR; |
| vb2_buffer_done(&buf->buf, VB2_BUF_STATE_ERROR); |
| } |
| |
| spin_unlock_irqrestore(&queue->irqlock, flags); |
| } |
| |
| static void uvc_wait_prepare(struct vb2_queue *vq) |
| { |
| struct uvc_video_queue *queue = vb2_get_drv_priv(vq); |
| |
| mutex_unlock(&queue->mutex); |
| } |
| |
| static void uvc_wait_finish(struct vb2_queue *vq) |
| { |
| struct uvc_video_queue *queue = vb2_get_drv_priv(vq); |
| |
| mutex_lock(&queue->mutex); |
| } |
| |
| static struct vb2_ops uvc_queue_qops = { |
| .queue_setup = uvc_queue_setup, |
| .buf_prepare = uvc_buffer_prepare, |
| .buf_queue = uvc_buffer_queue, |
| .wait_prepare = uvc_wait_prepare, |
| .wait_finish = uvc_wait_finish, |
| }; |
| |
| int uvcg_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type) |
| { |
| int ret; |
| |
| queue->queue.type = type; |
| queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF; |
| queue->queue.drv_priv = queue; |
| queue->queue.buf_struct_size = sizeof(struct uvc_buffer); |
| queue->queue.ops = &uvc_queue_qops; |
| queue->queue.mem_ops = &vb2_vmalloc_memops; |
| queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC |
| | V4L2_BUF_FLAG_TSTAMP_SRC_EOF; |
| ret = vb2_queue_init(&queue->queue); |
| if (ret) |
| return ret; |
| |
| mutex_init(&queue->mutex); |
| spin_lock_init(&queue->irqlock); |
| INIT_LIST_HEAD(&queue->irqqueue); |
| queue->flags = 0; |
| |
| return 0; |
| } |
| |
| /* |
| * Free the video buffers. |
| */ |
| void uvcg_free_buffers(struct uvc_video_queue *queue) |
| { |
| mutex_lock(&queue->mutex); |
| vb2_queue_release(&queue->queue); |
| mutex_unlock(&queue->mutex); |
| } |
| |
| /* |
| * Allocate the video buffers. |
| */ |
| int uvcg_alloc_buffers(struct uvc_video_queue *queue, |
| struct v4l2_requestbuffers *rb) |
| { |
| int ret; |
| |
| mutex_lock(&queue->mutex); |
| ret = vb2_reqbufs(&queue->queue, rb); |
| mutex_unlock(&queue->mutex); |
| |
| return ret ? ret : rb->count; |
| } |
| |
| int uvcg_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf) |
| { |
| int ret; |
| |
| mutex_lock(&queue->mutex); |
| ret = vb2_querybuf(&queue->queue, buf); |
| mutex_unlock(&queue->mutex); |
| |
| return ret; |
| } |
| |
| int uvcg_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf) |
| { |
| unsigned long flags; |
| int ret; |
| |
| mutex_lock(&queue->mutex); |
| ret = vb2_qbuf(&queue->queue, buf); |
| if (ret < 0) |
| goto done; |
| |
| spin_lock_irqsave(&queue->irqlock, flags); |
| ret = (queue->flags & UVC_QUEUE_PAUSED) != 0; |
| queue->flags &= ~UVC_QUEUE_PAUSED; |
| spin_unlock_irqrestore(&queue->irqlock, flags); |
| |
| done: |
| mutex_unlock(&queue->mutex); |
| return ret; |
| } |
| |
| /* |
| * Dequeue a video buffer. If nonblocking is false, block until a buffer is |
| * available. |
| */ |
| int uvcg_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf, |
| int nonblocking) |
| { |
| int ret; |
| |
| mutex_lock(&queue->mutex); |
| ret = vb2_dqbuf(&queue->queue, buf, nonblocking); |
| mutex_unlock(&queue->mutex); |
| |
| return ret; |
| } |
| |
| /* |
| * Poll the video queue. |
| * |
| * This function implements video queue polling and is intended to be used by |
| * the device poll handler. |
| */ |
| unsigned int uvcg_queue_poll(struct uvc_video_queue *queue, struct file *file, |
| poll_table *wait) |
| { |
| unsigned int ret; |
| |
| mutex_lock(&queue->mutex); |
| ret = vb2_poll(&queue->queue, file, wait); |
| mutex_unlock(&queue->mutex); |
| |
| return ret; |
| } |
| |
| int uvcg_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma) |
| { |
| int ret; |
| |
| mutex_lock(&queue->mutex); |
| ret = vb2_mmap(&queue->queue, vma); |
| mutex_unlock(&queue->mutex); |
| |
| return ret; |
| } |
| |
| #ifndef CONFIG_MMU |
| /* |
| * Get unmapped area. |
| * |
| * NO-MMU arch need this function to make mmap() work correctly. |
| */ |
| unsigned long uvcg_queue_get_unmapped_area(struct uvc_video_queue *queue, |
| unsigned long pgoff) |
| { |
| unsigned long ret; |
| |
| mutex_lock(&queue->mutex); |
| ret = vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0); |
| mutex_unlock(&queue->mutex); |
| return ret; |
| } |
| #endif |
| |
| /* |
| * Cancel the video buffers queue. |
| * |
| * Cancelling the queue marks all buffers on the irq queue as erroneous, |
| * wakes them up and removes them from the queue. |
| * |
| * If the disconnect parameter is set, further calls to uvc_queue_buffer will |
| * fail with -ENODEV. |
| * |
| * This function acquires the irq spinlock and can be called from interrupt |
| * context. |
| */ |
| void uvcg_queue_cancel(struct uvc_video_queue *queue, int disconnect) |
| { |
| struct uvc_buffer *buf; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&queue->irqlock, flags); |
| while (!list_empty(&queue->irqqueue)) { |
| buf = list_first_entry(&queue->irqqueue, struct uvc_buffer, |
| queue); |
| list_del(&buf->queue); |
| buf->state = UVC_BUF_STATE_ERROR; |
| vb2_buffer_done(&buf->buf, VB2_BUF_STATE_ERROR); |
| } |
| /* This must be protected by the irqlock spinlock to avoid race |
| * conditions between uvc_queue_buffer and the disconnection event that |
| * could result in an interruptible wait in uvc_dequeue_buffer. Do not |
| * blindly replace this logic by checking for the UVC_DEV_DISCONNECTED |
| * state outside the queue code. |
| */ |
| if (disconnect) |
| queue->flags |= UVC_QUEUE_DISCONNECTED; |
| spin_unlock_irqrestore(&queue->irqlock, flags); |
| } |
| |
| /* |
| * Enable or disable the video buffers queue. |
| * |
| * The queue must be enabled before starting video acquisition and must be |
| * disabled after stopping it. This ensures that the video buffers queue |
| * state can be properly initialized before buffers are accessed from the |
| * interrupt handler. |
| * |
| * Enabling the video queue initializes parameters (such as sequence number, |
| * sync pattern, ...). If the queue is already enabled, return -EBUSY. |
| * |
| * Disabling the video queue cancels the queue and removes all buffers from |
| * the main queue. |
| * |
| * This function can't be called from interrupt context. Use |
| * uvcg_queue_cancel() instead. |
| */ |
| int uvcg_queue_enable(struct uvc_video_queue *queue, int enable) |
| { |
| unsigned long flags; |
| int ret = 0; |
| |
| mutex_lock(&queue->mutex); |
| if (enable) { |
| ret = vb2_streamon(&queue->queue, queue->queue.type); |
| if (ret < 0) |
| goto done; |
| |
| queue->sequence = 0; |
| queue->buf_used = 0; |
| } else { |
| ret = vb2_streamoff(&queue->queue, queue->queue.type); |
| if (ret < 0) |
| goto done; |
| |
| spin_lock_irqsave(&queue->irqlock, flags); |
| INIT_LIST_HEAD(&queue->irqqueue); |
| |
| /* |
| * FIXME: We need to clear the DISCONNECTED flag to ensure that |
| * applications will be able to queue buffers for the next |
| * streaming run. However, clearing it here doesn't guarantee |
| * that the device will be reconnected in the meantime. |
| */ |
| queue->flags &= ~UVC_QUEUE_DISCONNECTED; |
| spin_unlock_irqrestore(&queue->irqlock, flags); |
| } |
| |
| done: |
| mutex_unlock(&queue->mutex); |
| return ret; |
| } |
| |
| /* called with &queue_irqlock held.. */ |
| struct uvc_buffer *uvcg_queue_next_buffer(struct uvc_video_queue *queue, |
| struct uvc_buffer *buf) |
| { |
| struct uvc_buffer *nextbuf; |
| |
| if ((queue->flags & UVC_QUEUE_DROP_INCOMPLETE) && |
| buf->length != buf->bytesused) { |
| buf->state = UVC_BUF_STATE_QUEUED; |
| vb2_set_plane_payload(&buf->buf, 0, 0); |
| return buf; |
| } |
| |
| list_del(&buf->queue); |
| if (!list_empty(&queue->irqqueue)) |
| nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer, |
| queue); |
| else |
| nextbuf = NULL; |
| |
| buf->buf.v4l2_buf.field = V4L2_FIELD_NONE; |
| buf->buf.v4l2_buf.sequence = queue->sequence++; |
| v4l2_get_timestamp(&buf->buf.v4l2_buf.timestamp); |
| |
| vb2_set_plane_payload(&buf->buf, 0, buf->bytesused); |
| vb2_buffer_done(&buf->buf, VB2_BUF_STATE_DONE); |
| |
| return nextbuf; |
| } |
| |
| struct uvc_buffer *uvcg_queue_head(struct uvc_video_queue *queue) |
| { |
| struct uvc_buffer *buf = NULL; |
| |
| if (!list_empty(&queue->irqqueue)) |
| buf = list_first_entry(&queue->irqqueue, struct uvc_buffer, |
| queue); |
| else |
| queue->flags |= UVC_QUEUE_PAUSED; |
| |
| return buf; |
| } |
| |