[media] usbtv: Add driver for Fushicai USBTV007 video frame grabber

Reverse-engineered driver for cheapo video digitizer, made from observations of
Windows XP driver. The protocol is not yet completely understood, so far we
don't provide any controls, only support a single format out of three and don't
support the audio device.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/usb/Kconfig

@@ -18,6 +18,7 @@ source "drivers/media/usb/zr364xx/Kconfig"
 source "drivers/media/usb/stkwebcam/Kconfig"
 source "drivers/media/usb/s2255/Kconfig"
 source "drivers/media/usb/sn9c102/Kconfig"
+source "drivers/media/usb/usbtv/Kconfig"
 endif
 
 if MEDIA_ANALOG_TV_SUPPORT

drivers/media/usb/Makefile

@@ -20,3 +20,4 @@ obj-$(CONFIG_VIDEO_STK1160) += stk1160/
 obj-$(CONFIG_VIDEO_CX231XX) += cx231xx/
 obj-$(CONFIG_VIDEO_TM6000) += tm6000/
 obj-$(CONFIG_VIDEO_EM28XX) += em28xx/
+obj-$(CONFIG_VIDEO_USBTV) += usbtv/

drivers/media/usb/usbtv/Kconfig

+config VIDEO_USBTV
+        tristate "USBTV007 video capture support"
+        depends on VIDEO_DEV
+        select VIDEOBUF2_VMALLOC
+
+        ---help---
+          This is a video4linux2 driver for USBTV007 based video capture devices.
+
+          To compile this driver as a module, choose M here: the
+          module will be called usbtv

drivers/media/usb/usbtv/Makefile

+obj-$(CONFIG_VIDEO_USBTV) += usbtv.o

drivers/media/usb/usbtv/usbtv.c

+/*
+ * Fushicai USBTV007 Video Grabber Driver
+ *
+ * Product web site:
+ * http://www.fushicai.com/products_detail/&productId=d05449ee-b690-42f9-a661-aa7353894bed.html
+ *
+ * Following LWN articles were very useful in construction of this driver:
+ * Video4Linux2 API series: http://lwn.net/Articles/203924/
+ * videobuf2 API explanation: http://lwn.net/Articles/447435/
+ * Thanks go to Jonathan Corbet for providing this quality documentation.
+ * He is awesome.
+ *
+ * Copyright (c) 2013 Lubomir Rintel
+ * All rights reserved.
+ * No physical hardware was harmed running Windows during the
+ * reverse-engineering activity
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL").
+ */
+
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/version.h>
+#include <linux/videodev2.h>
+
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-vmalloc.h>
+
+/* Hardware. */
+#define USBTV_VIDEO_ENDP	0x81
+#define USBTV_BASE		0xc000
+#define USBTV_REQUEST_REG	12
+
+/* Number of concurrent isochronous urbs submitted.
+ * Higher numbers was seen to overly saturate the USB bus. */
+#define USBTV_ISOC_TRANSFERS	16
+#define USBTV_ISOC_PACKETS	8
+
+#define USBTV_WIDTH		720
+#define USBTV_HEIGHT		480
+
+#define USBTV_CHUNK_SIZE	256
+#define USBTV_CHUNK		240
+#define USBTV_CHUNKS		(USBTV_WIDTH * USBTV_HEIGHT \
+					/ 2 / USBTV_CHUNK)
+
+/* Chunk header. */
+#define USBTV_MAGIC_OK(chunk)	((be32_to_cpu(chunk[0]) & 0xff000000) \
+							== 0x88000000)
+#define USBTV_FRAME_ID(chunk)	((be32_to_cpu(chunk[0]) & 0x00ff0000) >> 16)
+#define USBTV_ODD(chunk)	((be32_to_cpu(chunk[0]) & 0x0000f000) >> 15)
+#define USBTV_CHUNK_NO(chunk)	(be32_to_cpu(chunk[0]) & 0x00000fff)
+
+/* A single videobuf2 frame buffer. */
+struct usbtv_buf {
+	struct vb2_buffer vb;
+	struct list_head list;
+};
+
+/* Per-device structure. */
+struct usbtv {
+	struct device *dev;
+	struct usb_device *udev;
+	struct v4l2_device v4l2_dev;
+	struct video_device vdev;
+	struct vb2_queue vb2q;
+	struct mutex v4l2_lock;
+	struct mutex vb2q_lock;
+
+	/* List of videobuf2 buffers protected by a lock. */
+	spinlock_t buflock;
+	struct list_head bufs;
+
+	/* Number of currently processed frame, useful find
+	 * out when a new one begins. */
+	u32 frame_id;
+
+	int iso_size;
+	unsigned int sequence;
+	struct urb *isoc_urbs[USBTV_ISOC_TRANSFERS];
+};
+
+static int usbtv_setup_capture(struct usbtv *usbtv)
+{
+	int ret;
+	int pipe = usb_rcvctrlpipe(usbtv->udev, 0);
+	int i;
+	static const u16 protoregs[][2] = {
+		/* These seem to enable the device. */
+		{ USBTV_BASE + 0x0008, 0x0001 },
+		{ USBTV_BASE + 0x01d0, 0x00ff },
+		{ USBTV_BASE + 0x01d9, 0x0002 },
+
+		/* These seem to influence color parameters, such as
+		 * brightness, etc. */
+		{ USBTV_BASE + 0x0239, 0x0040 },
+		{ USBTV_BASE + 0x0240, 0x0000 },
+		{ USBTV_BASE + 0x0241, 0x0000 },
+		{ USBTV_BASE + 0x0242, 0x0002 },
+		{ USBTV_BASE + 0x0243, 0x0080 },
+		{ USBTV_BASE + 0x0244, 0x0012 },
+		{ USBTV_BASE + 0x0245, 0x0090 },
+		{ USBTV_BASE + 0x0246, 0x0000 },
+
+		{ USBTV_BASE + 0x0278, 0x002d },
+		{ USBTV_BASE + 0x0279, 0x000a },
+		{ USBTV_BASE + 0x027a, 0x0032 },
+		{ 0xf890, 0x000c },
+		{ 0xf894, 0x0086 },
+
+		{ USBTV_BASE + 0x00ac, 0x00c0 },
+		{ USBTV_BASE + 0x00ad, 0x0000 },
+		{ USBTV_BASE + 0x00a2, 0x0012 },
+		{ USBTV_BASE + 0x00a3, 0x00e0 },
+		{ USBTV_BASE + 0x00a4, 0x0028 },
+		{ USBTV_BASE + 0x00a5, 0x0082 },
+		{ USBTV_BASE + 0x00a7, 0x0080 },
+		{ USBTV_BASE + 0x0000, 0x0014 },
+		{ USBTV_BASE + 0x0006, 0x0003 },
+		{ USBTV_BASE + 0x0090, 0x0099 },
+		{ USBTV_BASE + 0x0091, 0x0090 },
+		{ USBTV_BASE + 0x0094, 0x0068 },
+		{ USBTV_BASE + 0x0095, 0x0070 },
+		{ USBTV_BASE + 0x009c, 0x0030 },
+		{ USBTV_BASE + 0x009d, 0x00c0 },
+		{ USBTV_BASE + 0x009e, 0x00e0 },
+		{ USBTV_BASE + 0x0019, 0x0006 },
+		{ USBTV_BASE + 0x008c, 0x00ba },
+		{ USBTV_BASE + 0x0101, 0x00ff },
+		{ USBTV_BASE + 0x010c, 0x00b3 },
+		{ USBTV_BASE + 0x01b2, 0x0080 },
+		{ USBTV_BASE + 0x01b4, 0x00a0 },
+		{ USBTV_BASE + 0x014c, 0x00ff },
+		{ USBTV_BASE + 0x014d, 0x00ca },
+		{ USBTV_BASE + 0x0113, 0x0053 },
+		{ USBTV_BASE + 0x0119, 0x008a },
+		{ USBTV_BASE + 0x013c, 0x0003 },
+		{ USBTV_BASE + 0x0150, 0x009c },
+		{ USBTV_BASE + 0x0151, 0x0071 },
+		{ USBTV_BASE + 0x0152, 0x00c6 },
+		{ USBTV_BASE + 0x0153, 0x0084 },
+		{ USBTV_BASE + 0x0154, 0x00bc },
+		{ USBTV_BASE + 0x0155, 0x00a0 },
+		{ USBTV_BASE + 0x0156, 0x00a0 },
+		{ USBTV_BASE + 0x0157, 0x009c },
+		{ USBTV_BASE + 0x0158, 0x001f },
+		{ USBTV_BASE + 0x0159, 0x0006 },
+		{ USBTV_BASE + 0x015d, 0x0000 },
+
+		{ USBTV_BASE + 0x0284, 0x0088 },
+		{ USBTV_BASE + 0x0003, 0x0004 },
+		{ USBTV_BASE + 0x001a, 0x0079 },
+		{ USBTV_BASE + 0x0100, 0x00d3 },
+		{ USBTV_BASE + 0x010e, 0x0068 },
+		{ USBTV_BASE + 0x010f, 0x009c },
+		{ USBTV_BASE + 0x0112, 0x00f0 },
+		{ USBTV_BASE + 0x0115, 0x0015 },
+		{ USBTV_BASE + 0x0117, 0x0000 },
+		{ USBTV_BASE + 0x0118, 0x00fc },
+		{ USBTV_BASE + 0x012d, 0x0004 },
+		{ USBTV_BASE + 0x012f, 0x0008 },
+		{ USBTV_BASE + 0x0220, 0x002e },
+		{ USBTV_BASE + 0x0225, 0x0008 },
+		{ USBTV_BASE + 0x024e, 0x0002 },
+		{ USBTV_BASE + 0x024f, 0x0001 },
+		{ USBTV_BASE + 0x0254, 0x005f },
+		{ USBTV_BASE + 0x025a, 0x0012 },
+		{ USBTV_BASE + 0x025b, 0x0001 },
+		{ USBTV_BASE + 0x0263, 0x001c },
+		{ USBTV_BASE + 0x0266, 0x0011 },
+		{ USBTV_BASE + 0x0267, 0x0005 },
+		{ USBTV_BASE + 0x024e, 0x0002 },
+		{ USBTV_BASE + 0x024f, 0x0002 },
+	};
+
+	for (i = 0; i < ARRAY_SIZE(protoregs); i++) {
+		u16 index = protoregs[i][0];
+		u16 value = protoregs[i][1];
+
+		ret = usb_control_msg(usbtv->udev, pipe, USBTV_REQUEST_REG,
+			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+			value, index, NULL, 0, 0);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+/* Called for each 256-byte image chunk.
+ * First word identifies the chunk, followed by 240 words of image
+ * data and padding. */
+static void usbtv_image_chunk(struct usbtv *usbtv, u32 *chunk)
+{
+	int frame_id, odd, chunk_no;
+	u32 *frame;
+	struct usbtv_buf *buf;
+	unsigned long flags;
+
+	/* Ignore corrupted lines. */
+	if (!USBTV_MAGIC_OK(chunk))
+		return;
+	frame_id = USBTV_FRAME_ID(chunk);
+	odd = USBTV_ODD(chunk);
+	chunk_no = USBTV_CHUNK_NO(chunk);
+
+	/* Deinterlace. TODO: Use interlaced frame format. */
+	chunk_no = (chunk_no - chunk_no % 3) * 2 + chunk_no % 3;
+	chunk_no += !odd * 3;
+
+	if (chunk_no >= USBTV_CHUNKS)
+		return;
+
+	/* Beginning of a frame. */
+	if (chunk_no == 0)
+		usbtv->frame_id = frame_id;
+
+	spin_lock_irqsave(&usbtv->buflock, flags);
+	if (list_empty(&usbtv->bufs)) {
+		/* No free buffers. Userspace likely too slow. */
+		spin_unlock_irqrestore(&usbtv->buflock, flags);
+		return;
+	}
+
+	/* First available buffer. */
+	buf = list_first_entry(&usbtv->bufs, struct usbtv_buf, list);
+	frame = vb2_plane_vaddr(&buf->vb, 0);
+
+	/* Copy the chunk. */
+	memcpy(&frame[chunk_no * USBTV_CHUNK], &chunk[1],
+			USBTV_CHUNK * sizeof(chunk[1]));
+
+	/* Last chunk in a frame, signalling an end */
+	if (usbtv->frame_id && chunk_no == USBTV_CHUNKS-1) {
+		int size = vb2_plane_size(&buf->vb, 0);
+
+		buf->vb.v4l2_buf.field = V4L2_FIELD_INTERLACED;
+		buf->vb.v4l2_buf.sequence = usbtv->sequence++;
+		v4l2_get_timestamp(&buf->vb.v4l2_buf.timestamp);
+		vb2_set_plane_payload(&buf->vb, 0, size);
+		vb2_buffer_done(&buf->vb, VB2_BUF_STATE_DONE);
+		list_del(&buf->list);
+	}
+
+	spin_unlock_irqrestore(&usbtv->buflock, flags);
+}
+
+/* Got image data. Each packet contains a number of 256-word chunks we
+ * compose the image from. */
+static void usbtv_iso_cb(struct urb *ip)
+{
+	int ret;
+	int i;
+	struct usbtv *usbtv = (struct usbtv *)ip->context;
+
+	switch (ip->status) {
+	/* All fine. */
+	case 0:
+		break;
+	/* Device disconnected or capture stopped? */
+	case -ENODEV:
+	case -ENOENT:
+	case -ECONNRESET:
+	case -ESHUTDOWN:
+		return;
+	/* Unknown error. Retry. */
+	default:
+		dev_warn(usbtv->dev, "Bad response for ISO request.\n");
+		goto resubmit;
+	}
+
+	for (i = 0; i < ip->number_of_packets; i++) {
+		int size = ip->iso_frame_desc[i].actual_length;
+		unsigned char *data = ip->transfer_buffer +
+				ip->iso_frame_desc[i].offset;
+		int offset;
+
+		for (offset = 0; USBTV_CHUNK_SIZE * offset < size; offset++)
+			usbtv_image_chunk(usbtv,
+				(u32 *)&data[USBTV_CHUNK_SIZE * offset]);
+	}
+
+resubmit:
+	ret = usb_submit_urb(ip, GFP_ATOMIC);
+	if (ret < 0)
+		dev_warn(usbtv->dev, "Could not resubmit ISO URB\n");
+}
+
+static struct urb *usbtv_setup_iso_transfer(struct usbtv *usbtv)
+{
+	struct urb *ip;
+	int size = usbtv->iso_size;
+	int i;
+
+	ip = usb_alloc_urb(USBTV_ISOC_PACKETS, GFP_KERNEL);
+	if (ip == NULL)
+		return NULL;
+
+	ip->dev = usbtv->udev;
+	ip->context = usbtv;
+	ip->pipe = usb_rcvisocpipe(usbtv->udev, USBTV_VIDEO_ENDP);
+	ip->interval = 1;
+	ip->transfer_flags = URB_ISO_ASAP;
+	ip->transfer_buffer = kzalloc(size * USBTV_ISOC_PACKETS,
+						GFP_KERNEL);
+	ip->complete = usbtv_iso_cb;
+	ip->number_of_packets = USBTV_ISOC_PACKETS;
+	ip->transfer_buffer_length = size * USBTV_ISOC_PACKETS;
+	for (i = 0; i < USBTV_ISOC_PACKETS; i++) {
+		ip->iso_frame_desc[i].offset = size * i;
+		ip->iso_frame_desc[i].length = size;
+	}
+
+	return ip;
+}
+
+static void usbtv_stop(struct usbtv *usbtv)
+{
+	int i;
+	unsigned long flags;
+
+	/* Cancel running transfers. */
+	for (i = 0; i < USBTV_ISOC_TRANSFERS; i++) {
+		struct urb *ip = usbtv->isoc_urbs[i];
+		if (ip == NULL)
+			continue;
+		usb_kill_urb(ip);
+		kfree(ip->transfer_buffer);
+		usb_free_urb(ip);
+		usbtv->isoc_urbs[i] = NULL;
+	}
+
+	/* Return buffers to userspace. */
+	spin_lock_irqsave(&usbtv->buflock, flags);
+	while (!list_empty(&usbtv->bufs)) {
+		struct usbtv_buf *buf = list_first_entry(&usbtv->bufs,
+						struct usbtv_buf, list);
+		vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
+		list_del(&buf->list);
+	}
+	spin_unlock_irqrestore(&usbtv->buflock, flags);
+}
+
+static int usbtv_start(struct usbtv *usbtv)
+{
+	int i;
+	int ret;
+
+	ret = usb_set_interface(usbtv->udev, 0, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = usbtv_setup_capture(usbtv);
+	if (ret < 0)
+		return ret;
+
+	ret = usb_set_interface(usbtv->udev, 0, 1);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < USBTV_ISOC_TRANSFERS; i++) {
+		struct urb *ip;
+
+		ip = usbtv_setup_iso_transfer(usbtv);
+		if (ip == NULL) {
+			ret = -ENOMEM;
+			goto start_fail;
+		}
+		usbtv->isoc_urbs[i] = ip;
+
+		ret = usb_submit_urb(ip, GFP_KERNEL);
+		if (ret < 0)
+			goto start_fail;
+	}
+
+	return 0;
+
+start_fail:
+	usbtv_stop(usbtv);
+	return ret;
+}
+
+struct usb_device_id usbtv_id_table[] = {
+	{ USB_DEVICE(0x1b71, 0x3002) },
+	{}
+};
+MODULE_DEVICE_TABLE(usb, usbtv_id_table);
+
+static int usbtv_querycap(struct file *file, void *priv,
+				struct v4l2_capability *cap)
+{
+	struct usbtv *dev = video_drvdata(file);
+
+	strlcpy(cap->driver, "usbtv", sizeof(cap->driver));
+	strlcpy(cap->card, "usbtv", sizeof(cap->card));
+	usb_make_path(dev->udev, cap->bus_info, sizeof(cap->bus_info));
+	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE;
+	cap->device_caps |= V4L2_CAP_READWRITE | V4L2_CAP_STREAMING;
+	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
+	return 0;
+}
+
+static int usbtv_enum_input(struct file *file, void *priv,
+					struct v4l2_input *i)
+{
+	if (i->index > 0)
+		return -EINVAL;
+
+	strlcpy(i->name, "Composite", sizeof(i->name));
+	i->type = V4L2_INPUT_TYPE_CAMERA;
+	i->std = V4L2_STD_525_60;
+	return 0;
+}
+
+static int usbtv_enum_fmt_vid_cap(struct file *file, void  *priv,
+					struct v4l2_fmtdesc *f)
+{
+	if (f->index > 0)
+		return -EINVAL;
+
+	strlcpy(f->description, "16 bpp YUY2, 4:2:2, packed",
+					sizeof(f->description));
+	f->pixelformat = V4L2_PIX_FMT_YUYV;
+	return 0;
+}
+
+static int usbtv_fmt_vid_cap(struct file *file, void *priv,
+					struct v4l2_format *f)
+{
+	f->fmt.pix.width = USBTV_WIDTH;
+	f->fmt.pix.height = USBTV_HEIGHT;
+	f->fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV;
+	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
+	f->fmt.pix.bytesperline = USBTV_WIDTH * 2;
+	f->fmt.pix.sizeimage = (f->fmt.pix.bytesperline * f->fmt.pix.height);
+	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
+	f->fmt.pix.priv = 0;
+	return 0;
+}
+
+static int usbtv_g_std(struct file *file, void *priv, v4l2_std_id *norm)
+{
+	*norm = V4L2_STD_525_60;
+	return 0;
+}
+
+static int usbtv_g_input(struct file *file, void *priv, unsigned int *i)
+{
+	*i = 0;
+	return 0;
+}
+
+static int usbtv_s_input(struct file *file, void *priv, unsigned int i)
+{
+	if (i > 0)
+		return -EINVAL;
+	return 0;
+}
+
+static int usbtv_s_std(struct file *file, void *priv, v4l2_std_id norm)
+{
+	if (norm & V4L2_STD_525_60)
+		return 0;
+	return -EINVAL;
+}
+
+struct v4l2_ioctl_ops usbtv_ioctl_ops = {
+	.vidioc_querycap = usbtv_querycap,
+	.vidioc_enum_input = usbtv_enum_input,
+	.vidioc_enum_fmt_vid_cap = usbtv_enum_fmt_vid_cap,
+	.vidioc_g_fmt_vid_cap = usbtv_fmt_vid_cap,
+	.vidioc_try_fmt_vid_cap = usbtv_fmt_vid_cap,
+	.vidioc_s_fmt_vid_cap = usbtv_fmt_vid_cap,
+	.vidioc_g_std = usbtv_g_std,
+	.vidioc_s_std = usbtv_s_std,
+	.vidioc_g_input = usbtv_g_input,
+	.vidioc_s_input = usbtv_s_input,
+
+	.vidioc_reqbufs = vb2_ioctl_reqbufs,
+	.vidioc_prepare_buf = vb2_ioctl_prepare_buf,
+	.vidioc_querybuf = vb2_ioctl_querybuf,
+	.vidioc_create_bufs = vb2_ioctl_create_bufs,
+	.vidioc_qbuf = vb2_ioctl_qbuf,
+	.vidioc_dqbuf = vb2_ioctl_dqbuf,
+	.vidioc_streamon = vb2_ioctl_streamon,
+	.vidioc_streamoff = vb2_ioctl_streamoff,
+};
+
+struct v4l2_file_operations usbtv_fops = {
+	.owner = THIS_MODULE,
+	.unlocked_ioctl = video_ioctl2,
+	.mmap = vb2_fop_mmap,
+	.open = v4l2_fh_open,
+	.release = vb2_fop_release,
+	.read = vb2_fop_read,
+	.poll = vb2_fop_poll,
+};
+
+static int usbtv_queue_setup(struct vb2_queue *vq,
+	const struct v4l2_format *v4l_fmt, unsigned int *nbuffers,
+	unsigned int *nplanes, unsigned int sizes[], void *alloc_ctxs[])
+{
+	if (*nbuffers < 2)
+		*nbuffers = 2;
+	*nplanes = 1;
+	sizes[0] = USBTV_CHUNK * USBTV_CHUNKS * sizeof(u32);
+
+	return 0;
+}
+
+static void usbtv_buf_queue(struct vb2_buffer *vb)
+{
+	struct usbtv *usbtv = vb2_get_drv_priv(vb->vb2_queue);
+	struct usbtv_buf *buf = container_of(vb, struct usbtv_buf, vb);
+	unsigned long flags;
+
+	if (usbtv->udev == NULL) {
+		vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
+		return;
+	}
+
+	spin_lock_irqsave(&usbtv->buflock, flags);
+	list_add_tail(&buf->list, &usbtv->bufs);
+	spin_unlock_irqrestore(&usbtv->buflock, flags);
+}
+
+static int usbtv_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct usbtv *usbtv = vb2_get_drv_priv(vq);
+
+	if (usbtv->udev == NULL)
+		return -ENODEV;
+
+	return usbtv_start(usbtv);
+}
+
+static int usbtv_stop_streaming(struct vb2_queue *vq)
+{
+	struct usbtv *usbtv = vb2_get_drv_priv(vq);
+
+	if (usbtv->udev == NULL)
+		return -ENODEV;
+
+	usbtv_stop(usbtv);
+	return 0;
+}
+
+struct vb2_ops usbtv_vb2_ops = {
+	.queue_setup = usbtv_queue_setup,
+	.buf_queue = usbtv_buf_queue,
+	.start_streaming = usbtv_start_streaming,
+	.stop_streaming = usbtv_stop_streaming,
+};
+
+static void usbtv_release(struct v4l2_device *v4l2_dev)
+{
+	struct usbtv *usbtv = container_of(v4l2_dev, struct usbtv, v4l2_dev);
+
+	v4l2_device_unregister(&usbtv->v4l2_dev);
+	vb2_queue_release(&usbtv->vb2q);
+	kfree(usbtv);
+}
+
+static int usbtv_probe(struct usb_interface *intf,
+	const struct usb_device_id *id)
+{
+	int ret;
+	int size;
+	struct device *dev = &intf->dev;
+	struct usbtv *usbtv;
+
+	/* Checks that the device is what we think it is. */
+	if (intf->num_altsetting != 2)
+		return -ENODEV;
+	if (intf->altsetting[1].desc.bNumEndpoints != 4)
+		return -ENODEV;
+
+	/* Packet size is split into 11 bits of base size and count of
+	 * extra multiplies of it.*/
+	size = usb_endpoint_maxp(&intf->altsetting[1].endpoint[0].desc);
+	size = (size & 0x07ff) * (((size & 0x1800) >> 11) + 1);
+
+	/* Device structure */
+	usbtv = kzalloc(sizeof(struct usbtv), GFP_KERNEL);
+	if (usbtv == NULL)
+		return -ENOMEM;
+	usbtv->dev = dev;
+	usbtv->udev = usb_get_dev(interface_to_usbdev(intf));
+	usbtv->iso_size = size;
+	spin_lock_init(&usbtv->buflock);
+	mutex_init(&usbtv->v4l2_lock);
+	mutex_init(&usbtv->vb2q_lock);
+	INIT_LIST_HEAD(&usbtv->bufs);
+
+	/* videobuf2 structure */
+	usbtv->vb2q.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	usbtv->vb2q.io_modes = VB2_MMAP | VB2_USERPTR | VB2_READ;
+	usbtv->vb2q.drv_priv = usbtv;
+	usbtv->vb2q.buf_struct_size = sizeof(struct usbtv_buf);
+	usbtv->vb2q.ops = &usbtv_vb2_ops;
+	usbtv->vb2q.mem_ops = &vb2_vmalloc_memops;
+	usbtv->vb2q.timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+	usbtv->vb2q.lock = &usbtv->vb2q_lock;
+	ret = vb2_queue_init(&usbtv->vb2q);
+	if (ret < 0) {
+		dev_warn(dev, "Could not initialize videobuf2 queue\n");
+		goto usbtv_fail;
+	}
+
+	/* v4l2 structure */
+	usbtv->v4l2_dev.release = usbtv_release;
+	ret = v4l2_device_register(dev, &usbtv->v4l2_dev);
+	if (ret < 0) {
+		dev_warn(dev, "Could not register v4l2 device\n");
+		goto v4l2_fail;
+	}
+
+	usb_set_intfdata(intf, usbtv);
+
+	/* Video structure */
+	strlcpy(usbtv->vdev.name, "usbtv", sizeof(usbtv->vdev.name));
+	usbtv->vdev.v4l2_dev = &usbtv->v4l2_dev;
+	usbtv->vdev.release = video_device_release_empty;
+	usbtv->vdev.fops = &usbtv_fops;
+	usbtv->vdev.ioctl_ops = &usbtv_ioctl_ops;
+	usbtv->vdev.tvnorms = V4L2_STD_525_60;
+	usbtv->vdev.queue = &usbtv->vb2q;
+	usbtv->vdev.lock = &usbtv->v4l2_lock;
+	set_bit(V4L2_FL_USE_FH_PRIO, &usbtv->vdev.flags);
+	video_set_drvdata(&usbtv->vdev, usbtv);
+	ret = video_register_device(&usbtv->vdev, VFL_TYPE_GRABBER, -1);
+	if (ret < 0) {
+		dev_warn(dev, "Could not register video device\n");
+		goto vdev_fail;
+	}
+
+	dev_info(dev, "Fushicai USBTV007 Video Grabber\n");
+	return 0;
+
+vdev_fail:
+	v4l2_device_unregister(&usbtv->v4l2_dev);
+v4l2_fail:
+	vb2_queue_release(&usbtv->vb2q);
+usbtv_fail:
+	kfree(usbtv);
+
+	return ret;
+}
+
+static void usbtv_disconnect(struct usb_interface *intf)
+{
+	struct usbtv *usbtv = usb_get_intfdata(intf);
+
+	mutex_lock(&usbtv->vb2q_lock);
+	mutex_lock(&usbtv->v4l2_lock);
+
+	usbtv_stop(usbtv);
+	usb_set_intfdata(intf, NULL);
+	video_unregister_device(&usbtv->vdev);
+	v4l2_device_disconnect(&usbtv->v4l2_dev);
+	usb_put_dev(usbtv->udev);
+	usbtv->udev = NULL;
+
+	mutex_unlock(&usbtv->v4l2_lock);
+	mutex_unlock(&usbtv->vb2q_lock);
+
+	v4l2_device_put(&usbtv->v4l2_dev);
+}
+
+MODULE_AUTHOR("Lubomir Rintel");
+MODULE_DESCRIPTION("Fushicai USBTV007 Video Grabber Driver");
+MODULE_LICENSE("Dual BSD/GPL");
+
+struct usb_driver usbtv_usb_driver = {
+	.name = "usbtv",
+	.id_table = usbtv_id_table,
+	.probe = usbtv_probe,
+	.disconnect = usbtv_disconnect,
+};
+
+module_usb_driver(usbtv_usb_driver);