--- /dev/null
+/*
+ * 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/videobuf2-vmalloc.h>
+
+#include "uvcvideo.h"
+
+/* ------------------------------------------------------------------------
+ * Video buffers queue management.
+ *
+ * Video queues is initialized by uvc_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.
+ */
+
+static inline struct uvc_streaming *
+uvc_queue_to_stream(struct uvc_video_queue *queue)
+{
+ return container_of(queue, struct uvc_streaming, queue);
+}
+
+/*
+ * Return all queued buffers to videobuf2 in the requested state.
+ *
+ * This function must be called with the queue spinlock held.
+ */
+static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
+ enum uvc_buffer_state state)
+{
+ enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR
+ ? VB2_BUF_STATE_ERROR
+ : VB2_BUF_STATE_QUEUED;
+
+ while (!list_empty(&queue->irqqueue)) {
+ struct uvc_buffer *buf = list_first_entry(&queue->irqqueue,
+ struct uvc_buffer,
+ queue);
+ list_del(&buf->queue);
+ buf->state = state;
+ vb2_buffer_done(&buf->buf, vb2_state);
+ }
+}
+
+/* -----------------------------------------------------------------------------
+ * 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_streaming *stream = uvc_queue_to_stream(queue);
+
+ /* Make sure the image size is large enough. */
+ if (fmt && fmt->fmt.pix.sizeimage < stream->ctrl.dwMaxVideoFrameSize)
+ return -EINVAL;
+
+ *nplanes = 1;
+
+ sizes[0] = fmt ? fmt->fmt.pix.sizeimage
+ : stream->ctrl.dwMaxVideoFrameSize;
+
+ 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->error = 0;
+ 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_buffer_finish(struct vb2_buffer *vb)
+{
+ struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
+ struct uvc_streaming *stream = uvc_queue_to_stream(queue);
+ struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
+
+ if (vb->state == VB2_BUF_STATE_DONE)
+ uvc_video_clock_update(stream, &vb->v4l2_buf, buf);
+}
+
+static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+ struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+ struct uvc_streaming *stream = uvc_queue_to_stream(queue);
+ unsigned long flags;
+ int ret;
+
+ queue->buf_used = 0;
+
+ ret = uvc_video_enable(stream, 1);
+ if (ret == 0)
+ return 0;
+
+ spin_lock_irqsave(&queue->irqlock, flags);
+ uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
+ spin_unlock_irqrestore(&queue->irqlock, flags);
+
+ return ret;
+}
+
+static void uvc_stop_streaming(struct vb2_queue *vq)
+{
+ struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+ struct uvc_streaming *stream = uvc_queue_to_stream(queue);
+ unsigned long flags;
+
+ uvc_video_enable(stream, 0);
+
+ spin_lock_irqsave(&queue->irqlock, flags);
+ uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
+ spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+static struct vb2_ops uvc_queue_qops = {
+ .queue_setup = uvc_queue_setup,
+ .buf_prepare = uvc_buffer_prepare,
+ .buf_queue = uvc_buffer_queue,
+ .buf_finish = uvc_buffer_finish,
+ .wait_prepare = vb2_ops_wait_prepare,
+ .wait_finish = vb2_ops_wait_finish,
+ .start_streaming = uvc_start_streaming,
+ .stop_streaming = uvc_stop_streaming,
+};
+
+int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
+ int drop_corrupted)
+{
+ 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_SOE;
+ queue->queue.lock = &queue->mutex;
+ 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 = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0;
+
+ return 0;
+}
+
+void uvc_queue_release(struct uvc_video_queue *queue)
+{
+ mutex_lock(&queue->mutex);
+ vb2_queue_release(&queue->queue);
+ mutex_unlock(&queue->mutex);
+}
+
+/* -----------------------------------------------------------------------------
+ * V4L2 queue operations
+ */
+
+int uvc_request_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 uvc_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 uvc_create_buffers(struct uvc_video_queue *queue,
+ struct v4l2_create_buffers *cb)
+{
+ int ret;
+
+ mutex_lock(&queue->mutex);
+ ret = vb2_create_bufs(&queue->queue, cb);
+ mutex_unlock(&queue->mutex);
+
+ return ret;
+}
+
+int uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
+{
+ int ret;
+
+ mutex_lock(&queue->mutex);
+ ret = vb2_qbuf(&queue->queue, buf);
+ mutex_unlock(&queue->mutex);
+
+ return ret;
+}
+
+int uvc_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;
+}
+
+int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
+{
+ int ret;
+
+ mutex_lock(&queue->mutex);
+ ret = vb2_streamon(&queue->queue, type);
+ mutex_unlock(&queue->mutex);
+
+ return ret;
+}
+
+int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
+{
+ int ret;
+
+ mutex_lock(&queue->mutex);
+ ret = vb2_streamoff(&queue->queue, type);
+ mutex_unlock(&queue->mutex);
+
+ return ret;
+}
+
+int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
+{
+ return vb2_mmap(&queue->queue, vma);
+}
+
+#ifndef CONFIG_MMU
+unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
+ unsigned long pgoff)
+{
+ return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
+}
+#endif
+
+unsigned int uvc_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;
+}
+
+/* -----------------------------------------------------------------------------
+ *
+ */
+
+/*
+ * Check if buffers have been allocated.
+ */
+int uvc_queue_allocated(struct uvc_video_queue *queue)
+{
+ int allocated;
+
+ mutex_lock(&queue->mutex);
+ allocated = vb2_is_busy(&queue->queue);
+ mutex_unlock(&queue->mutex);
+
+ return allocated;
+}
+
+/*
+ * 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 uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&queue->irqlock, flags);
+ uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
+ /* This must be protected by the irqlock spinlock to avoid race
+ * conditions between uvc_buffer_queue 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_QUEUE_DISCONNECTED
+ * state outside the queue code.
+ */
+ if (disconnect)
+ queue->flags |= UVC_QUEUE_DISCONNECTED;
+ spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
+ struct uvc_buffer *buf)
+{
+ struct uvc_buffer *nextbuf;
+ unsigned long flags;
+
+ if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
+ buf->error = 0;
+ buf->state = UVC_BUF_STATE_QUEUED;
+ buf->bytesused = 0;
+ vb2_set_plane_payload(&buf->buf, 0, 0);
+ return buf;
+ }
+
+ spin_lock_irqsave(&queue->irqlock, flags);
+ list_del(&buf->queue);
+ if (!list_empty(&queue->irqqueue))
+ nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
+ queue);
+ else
+ nextbuf = NULL;
+ spin_unlock_irqrestore(&queue->irqlock, flags);
+
+ buf->state = buf->error ? VB2_BUF_STATE_ERROR : UVC_BUF_STATE_DONE;
+ vb2_set_plane_payload(&buf->buf, 0, buf->bytesused);
+ vb2_buffer_done(&buf->buf, VB2_BUF_STATE_DONE);
+
+ return nextbuf;
+}
Code Review / kvmfornfv.git / blobdiff