1 files changed, 360 insertions, 0 deletions
diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
new file mode 100644
index 000000000000..5577381b5bf0
--- /dev/null
+++ b/drivers/media/usb/uvc/uvc_queue.c
@@ -0,0 +1,360 @@
+/*
+ *      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.
+ */
+
+/* -----------------------------------------------------------------------------
+ * 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 =
+			container_of(queue, struct uvc_streaming, queue);
+
+	if (*nbuffers > UVC_MAX_VIDEO_BUFFERS)
+		*nbuffers = UVC_MAX_VIDEO_BUFFERS;
+
+	*nplanes = 1;
+
+	sizes[0] = 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 int uvc_buffer_finish(struct vb2_buffer *vb)
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
+	struct uvc_streaming *stream =
+			container_of(queue, struct uvc_streaming, queue);
+	struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
+
+	uvc_video_clock_update(stream, &vb->v4l2_buf, buf);
+	return 0;
+}
+
+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,
+};
+
+void uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
+		    int drop_corrupted)
+{
+	queue->queue.type = type;
+	queue->queue.io_modes = VB2_MMAP | VB2_USERPTR;
+	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;
+	vb2_queue_init(&queue->queue);
+
+	mutex_init(&queue->mutex);
+	spin_lock_init(&queue->irqlock);
+	INIT_LIST_HEAD(&queue->irqqueue);
+	queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0;
+}
+
+/* -----------------------------------------------------------------------------
+ * V4L2 queue operations
+ */
+
+int uvc_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;
+}
+
+void uvc_free_buffers(struct uvc_video_queue *queue)
+{
+	mutex_lock(&queue->mutex);
+	vb2_queue_release(&queue->queue);
+	mutex_unlock(&queue->mutex);
+}
+
+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_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_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
+unsigned long uvc_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
+
+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;
+}
+
+/*
+ * 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 returns -EBUSY if the queue is already enabled.
+ *
+ * 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
+ * uvc_queue_cancel() instead.
+ */
+int uvc_queue_enable(struct uvc_video_queue *queue, int enable)
+{
+	unsigned long flags;
+	int ret;
+
+	mutex_lock(&queue->mutex);
+	if (enable) {
+		ret = vb2_streamon(&queue->queue, queue->queue.type);
+		if (ret < 0)
+			goto done;
+
+		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);
+		spin_unlock_irqrestore(&queue->irqlock, flags);
+	}
+
+done:
+	mutex_unlock(&queue->mutex);
+	return ret;
+}
+
+/*
+ * 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)
+{
+	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_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;
+}