1 files changed, 350 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c
new file mode 100644
index 000000000..cab1e3046
--- /dev/null
+++ b/drivers/usb/gadget/function/uvc_queue.c
@@ -0,0 +1,350 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *	uvc_queue.c  --  USB Video Class driver - Buffers management
+ *
+ *	Copyright (C) 2005-2010
+ *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ */
+
+#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,
+			   unsigned int *nbuffers, unsigned int *nplanes,
+			   unsigned int sizes[], struct device *alloc_devs[])
+{
+	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 vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
+
+	if (vb->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->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 vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct uvc_buffer *buf = container_of(vbuf, 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(vb, VB2_BUF_STATE_ERROR);
+	}
+
+	spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+static const struct vb2_ops uvc_queue_qops = {
+	.queue_setup = uvc_queue_setup,
+	.buf_prepare = uvc_buffer_prepare,
+	.buf_queue = uvc_buffer_queue,
+	.wait_prepare = vb2_ops_wait_prepare,
+	.wait_finish = vb2_ops_wait_finish,
+};
+
+int uvcg_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
+		    struct mutex *lock)
+{
+	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.lock = lock;
+	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;
+
+	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)
+{
+	vb2_queue_release(&queue->queue);
+}
+
+/*
+ * Allocate the video buffers.
+ */
+int uvcg_alloc_buffers(struct uvc_video_queue *queue,
+			      struct v4l2_requestbuffers *rb)
+{
+	int ret;
+
+	ret = vb2_reqbufs(&queue->queue, rb);
+
+	return ret ? ret : rb->count;
+}
+
+int uvcg_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
+{
+	return vb2_querybuf(&queue->queue, buf);
+}
+
+int uvcg_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
+{
+	unsigned long flags;
+	int ret;
+
+	ret = vb2_qbuf(&queue->queue, NULL, buf);
+	if (ret < 0)
+		return ret;
+
+	spin_lock_irqsave(&queue->irqlock, flags);
+	ret = (queue->flags & UVC_QUEUE_PAUSED) != 0;
+	queue->flags &= ~UVC_QUEUE_PAUSED;
+	spin_unlock_irqrestore(&queue->irqlock, flags);
+	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)
+{
+	return vb2_dqbuf(&queue->queue, buf, nonblocking);
+}
+
+/*
+ * Poll the video queue.
+ *
+ * This function implements video queue polling and is intended to be used by
+ * the device poll handler.
+ */
+__poll_t uvcg_queue_poll(struct uvc_video_queue *queue, struct file *file,
+			     poll_table *wait)
+{
+	return vb2_poll(&queue->queue, file, wait);
+}
+
+int uvcg_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
+{
+	return vb2_mmap(&queue->queue, vma);
+}
+
+#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)
+{
+	return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
+}
+#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, VB2_BUF_STATE_ERROR);
+	}
+	queue->buf_used = 0;
+
+	/* 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;
+
+	if (enable) {
+		ret = vb2_streamon(&queue->queue, queue->queue.type);
+		if (ret < 0)
+			return ret;
+
+		queue->sequence = 0;
+		queue->buf_used = 0;
+	} else {
+		ret = vb2_streamoff(&queue->queue, queue->queue.type);
+		if (ret < 0)
+			return ret;
+
+		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);
+	}
+
+	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.vb2_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.field = V4L2_FIELD_NONE;
+	buf->buf.sequence = queue->sequence++;
+	buf->buf.vb2_buf.timestamp = ktime_get_ns();
+
+	vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
+	vb2_buffer_done(&buf->buf.vb2_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;
+}
+