media: cxusb: add analog mode support for Medion MD95700

This patch adds support for analog part of Medion 95700 in the cxusb
driver.

What works:
* Video capture at various sizes with sequential fields,
* Input switching (TV Tuner, Composite, S-Video),
* TV and radio tuning,
* Video standard switching and auto detection,
* Radio mode switching (stereo / mono),
* Unplugging while capturing,
* DVB / analog coexistence.

What does not work yet:
* Audio,
* VBI,
* Picture controls.

Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil-cisco@xs4all.nl: remove left-over commented-out debug message]
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

5 files changed, 1968 insertions, 4 deletions

diff --git a/drivers/media/usb/dvb-usb/Kconfig b/drivers/media/usb/dvb-usb/Kconfig
index 87dbae875177..1a3e5f965ae4 100644
--- a/drivers/media/usb/dvb-usb/Kconfig
+++ b/drivers/media/usb/dvb-usb/Kconfig
@@ -139,12 +139,24 @@ config DVB_USB_CXUSB
 	select MEDIA_TUNER_SI2157 if MEDIA_SUBDRV_AUTOSELECT
 	help
 	  Say Y here to support the Conexant USB2.0 hybrid reference design.
-	  Currently, only DVB and ATSC modes are supported, analog mode
-	  shall be added in the future. Devices that require this module:
+	  DVB and ATSC modes are supported, for a basic analog mode support
+	  see the next option ("Analog support for the Conexant USB2.0 hybrid
+	  reference design").
+	  Devices that require this module:
 
 	  Medion MD95700 hybrid USB2.0 device.
 	  DViCO FusionHDTV (Bluebird) USB2.0 devices
 
+config DVB_USB_CXUSB_ANALOG
+	bool "Analog support for the Conexant USB2.0 hybrid reference design"
+	depends on DVB_USB_CXUSB && VIDEO_V4L2
+	select VIDEO_CX25840
+	select VIDEOBUF2_VMALLOC
+	help
+	  Say Y here to enable basic analog mode support for the Conexant
+	  USB2.0 hybrid reference design.
+	  Currently this mode is supported only on a Medion MD95700 device.
+
 config DVB_USB_M920X
 	tristate "Uli m920x DVB-T USB2.0 support"
 	depends on DVB_USB
diff --git a/drivers/media/usb/dvb-usb/Makefile b/drivers/media/usb/dvb-usb/Makefile
index 407d90ca8be0..28e4806a87cd 100644
--- a/drivers/media/usb/dvb-usb/Makefile
+++ b/drivers/media/usb/dvb-usb/Makefile
@@ -42,6 +42,9 @@ dvb-usb-digitv-objs := digitv.o
 obj-$(CONFIG_DVB_USB_DIGITV) += dvb-usb-digitv.o
 
 dvb-usb-cxusb-objs := cxusb.o
+ifeq ($(CONFIG_DVB_USB_CXUSB_ANALOG),y)
+dvb-usb-cxusb-objs += cxusb-analog.o
+endif
 obj-$(CONFIG_DVB_USB_CXUSB) += dvb-usb-cxusb.o
 
 dvb-usb-ttusb2-objs := ttusb2.o
diff --git a/drivers/media/usb/dvb-usb/cxusb-analog.c b/drivers/media/usb/dvb-usb/cxusb-analog.c
new file mode 100644
index 000000000000..8df6c33bbbb1
--- /dev/null
+++ b/drivers/media/usb/dvb-usb/cxusb-analog.c
@@ -0,0 +1,1845 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// DVB USB compliant linux driver for Conexant USB reference design -
+// (analog part).
+//
+// Copyright (C) 2011, 2017, 2018
+//	Maciej S. Szmigiero (mail@maciej.szmigiero.name)
+//
+// In case there are new analog / DVB-T hybrid devices released in the market
+// using the same general design as Medion MD95700: a CX25840 video decoder
+// outputting a BT.656 stream to a USB bridge chip which then forwards it to
+// the host in isochronous USB packets this code should be made generic, with
+// board specific bits implemented via separate card structures.
+//
+// This is, however, unlikely as the Medion model was released
+// years ago (in 2005).
+//
+// TODO:
+//  * audio support,
+//  * finish radio support (requires audio of course),
+//  * VBI support,
+//  * controls support
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/timekeeping.h>
+#include <linux/vmalloc.h>
+#include <media/drv-intf/cx25840.h>
+#include <media/tuner.h>
+#include <media/v4l2-fh.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-subdev.h>
+#include <media/videobuf2-vmalloc.h>
+
+#include "cxusb.h"
+
+static int cxusb_medion_v_queue_setup(struct vb2_queue *q,
+				      unsigned int *num_buffers,
+				      unsigned int *num_planes,
+				      unsigned int sizes[],
+				      struct device *alloc_devs[])
+{
+	struct dvb_usb_device *dvbdev = vb2_get_drv_priv(q);
+	struct cxusb_medion_dev *cxdev = dvbdev->priv;
+	unsigned int size = cxdev->width * cxdev->height * 2;
+
+	if (*num_planes > 0) {
+		if (*num_planes != 1)
+			return -EINVAL;
+
+		if (sizes[0] < size)
+			return -EINVAL;
+	} else {
+		*num_planes = 1;
+		sizes[0] = size;
+	}
+
+	return 0;
+}
+
+static int cxusb_medion_v_buf_init(struct vb2_buffer *vb)
+{
+	struct dvb_usb_device *dvbdev = vb2_get_drv_priv(vb->vb2_queue);
+	struct cxusb_medion_dev *cxdev = dvbdev->priv;
+
+	cxusb_vprintk(dvbdev, OPS, "buffer init\n");
+
+	if (vb2_plane_size(vb, 0) < cxdev->width * cxdev->height * 2)
+		return -ENOMEM;
+
+	cxusb_vprintk(dvbdev, OPS, "buffer OK\n");
+
+	return 0;
+}
+
+static void cxusb_auxbuf_init(struct dvb_usb_device *dvbdev,
+			      struct cxusb_medion_auxbuf *auxbuf,
+			      u8 *buf, unsigned int len)
+{
+	cxusb_vprintk(dvbdev, AUXB, "initializing auxbuf of len %u\n", len);
+
+	auxbuf->buf = buf;
+	auxbuf->len = len;
+	auxbuf->paylen = 0;
+}
+
+static void cxusb_auxbuf_head_trim(struct dvb_usb_device *dvbdev,
+				   struct cxusb_medion_auxbuf *auxbuf,
+				   unsigned int pos)
+{
+	if (pos == 0)
+		return;
+
+	if (WARN_ON(pos > auxbuf->paylen))
+		return;
+
+	cxusb_vprintk(dvbdev, AUXB,
+		      "trimming auxbuf len by %u to %u\n",
+		      pos, auxbuf->paylen - pos);
+
+	memmove(auxbuf->buf, auxbuf->buf + pos, auxbuf->paylen - pos);
+	auxbuf->paylen -= pos;
+}
+
+static unsigned int cxusb_auxbuf_paylen(struct cxusb_medion_auxbuf *auxbuf)
+{
+	return auxbuf->paylen;
+}
+
+static bool cxusb_auxbuf_make_space(struct dvb_usb_device *dvbdev,
+				    struct cxusb_medion_auxbuf *auxbuf,
+				    unsigned int howmuch)
+{
+	unsigned int freespace;
+
+	if (WARN_ON(howmuch >= auxbuf->len))
+		howmuch = auxbuf->len - 1;
+
+	freespace = auxbuf->len - cxusb_auxbuf_paylen(auxbuf);
+
+	cxusb_vprintk(dvbdev, AUXB, "freespace is %u\n", freespace);
+
+	if (freespace >= howmuch)
+		return true;
+
+	howmuch -= freespace;
+
+	cxusb_vprintk(dvbdev, AUXB, "will overwrite %u bytes of buffer\n",
+		      howmuch);
+
+	cxusb_auxbuf_head_trim(dvbdev, auxbuf, howmuch);
+
+	return false;
+}
+
+/* returns false if some data was overwritten */
+static bool cxusb_auxbuf_append_urb(struct dvb_usb_device *dvbdev,
+				    struct cxusb_medion_auxbuf *auxbuf,
+				    struct urb *urb)
+{
+	unsigned long len;
+	int i;
+	bool ret;
+
+	for (i = 0, len = 0; i < urb->number_of_packets; i++)
+		len += urb->iso_frame_desc[i].actual_length;
+
+	ret = cxusb_auxbuf_make_space(dvbdev, auxbuf, len);
+
+	for (i = 0; i < urb->number_of_packets; i++) {
+		unsigned int to_copy;
+
+		to_copy = urb->iso_frame_desc[i].actual_length;
+
+		memcpy(auxbuf->buf + auxbuf->paylen, urb->transfer_buffer +
+		       urb->iso_frame_desc[i].offset, to_copy);
+
+		auxbuf->paylen += to_copy;
+	}
+
+	return ret;
+}
+
+static bool cxusb_auxbuf_copy(struct cxusb_medion_auxbuf *auxbuf,
+			      unsigned int pos, unsigned char *dest,
+			      unsigned int len)
+{
+	if (pos + len > auxbuf->paylen)
+		return false;
+
+	memcpy(dest, auxbuf->buf + pos, len);
+
+	return true;
+}
+
+static bool cxusb_medion_cf_refc_fld_chg(struct dvb_usb_device *dvbdev,
+					 struct cxusb_bt656_params *bt656,
+					 bool firstfield,
+					 unsigned int maxlines,
+					 unsigned int maxlinesamples,
+					 unsigned char buf[4])
+{
+	bool firstfield_code = (buf[3] & CXUSB_BT656_FIELD_MASK) ==
+		CXUSB_BT656_FIELD_1;
+	unsigned int remlines;
+
+	if (bt656->line == 0 || firstfield == firstfield_code)
+		return false;
+
+	if (bt656->fmode == LINE_SAMPLES) {
+		unsigned int remsamples = maxlinesamples -
+			bt656->linesamples;
+
+		cxusb_vprintk(dvbdev, BT656,
+			      "field %c after line %u field change\n",
+			      firstfield ? '1' : '2', bt656->line);
+
+		if (bt656->buf != NULL && remsamples > 0) {
+			memset(bt656->buf, 0, remsamples);
+			bt656->buf += remsamples;
+
+			cxusb_vprintk(dvbdev, BT656,
+				      "field %c line %u %u samples still remaining (of %u)\n",
+				      firstfield ? '1' : '2',
+				      bt656->line, remsamples,
+				      maxlinesamples);
+		}
+
+		bt656->line++;
+	}
+
+	remlines = maxlines - bt656->line;
+	if (bt656->buf != NULL && remlines > 0) {
+		memset(bt656->buf, 0, remlines * maxlinesamples);
+		bt656->buf += remlines * maxlinesamples;
+
+		cxusb_vprintk(dvbdev, BT656,
+			      "field %c %u lines still remaining (of %u)\n",
+			      firstfield ? '1' : '2', remlines,
+			      maxlines);
+	}
+
+	return true;
+}
+
+static void cxusb_medion_cf_refc_start_sch(struct dvb_usb_device *dvbdev,
+					   struct cxusb_bt656_params *bt656,
+					   bool firstfield,
+					   unsigned char buf[4])
+{
+	bool firstfield_code = (buf[3] & CXUSB_BT656_FIELD_MASK) ==
+		CXUSB_BT656_FIELD_1;
+	bool sav_code = (buf[3] & CXUSB_BT656_SEAV_MASK) ==
+		CXUSB_BT656_SEAV_SAV;
+	bool vbi_code = (buf[3] & CXUSB_BT656_VBI_MASK) ==
+		CXUSB_BT656_VBI_ON;
+
+	if (!sav_code || firstfield != firstfield_code)
+		return;
+
+	if (!vbi_code) {
+		cxusb_vprintk(dvbdev, BT656, "line start @ pos %u\n",
+			      bt656->pos);
+
+		bt656->linesamples = 0;
+		bt656->fmode = LINE_SAMPLES;
+	} else {
+		cxusb_vprintk(dvbdev, BT656, "VBI start @ pos %u\n",
+			      bt656->pos);
+
+		bt656->fmode = VBI_SAMPLES;
+	}
+}
+
+static void cxusb_medion_cf_refc_line_smpl(struct dvb_usb_device *dvbdev,
+					   struct cxusb_bt656_params *bt656,
+					   bool firstfield,
+					   unsigned int maxlinesamples,
+					   unsigned char buf[4])
+{
+	bool sav_code = (buf[3] & CXUSB_BT656_SEAV_MASK) ==
+		CXUSB_BT656_SEAV_SAV;
+	unsigned int remsamples;
+
+	if (sav_code)
+		cxusb_vprintk(dvbdev, BT656,
+			      "SAV in line samples @ line %u, pos %u\n",
+			      bt656->line, bt656->pos);
+
+	remsamples = maxlinesamples - bt656->linesamples;
+	if (bt656->buf != NULL && remsamples > 0) {
+		memset(bt656->buf, 0, remsamples);
+		bt656->buf += remsamples;
+
+		cxusb_vprintk(dvbdev, BT656,
+			      "field %c line %u %u samples still remaining (of %u)\n",
+			      firstfield ? '1' : '2', bt656->line, remsamples,
+			      maxlinesamples);
+	}
+
+	bt656->fmode = START_SEARCH;
+	bt656->line++;
+}
+
+static void cxusb_medion_cf_refc_vbi_smpl(struct dvb_usb_device *dvbdev,
+					  struct cxusb_bt656_params *bt656,
+					  unsigned char buf[4])
+{
+	bool sav_code = (buf[3] & CXUSB_BT656_SEAV_MASK) ==
+		CXUSB_BT656_SEAV_SAV;
+
+	if (sav_code)
+		cxusb_vprintk(dvbdev, BT656, "SAV in VBI samples @ pos %u\n",
+			      bt656->pos);
+
+	bt656->fmode = START_SEARCH;
+}
+
+/* returns whether the whole 4-byte code should be skipped in the buffer */
+static bool cxusb_medion_cf_ref_code(struct dvb_usb_device *dvbdev,
+				     struct cxusb_bt656_params *bt656,
+				     bool firstfield,
+				     unsigned int maxlines,
+				     unsigned int maxlinesamples,
+				     unsigned char buf[4])
+{
+	if (bt656->fmode == START_SEARCH)
+		cxusb_medion_cf_refc_start_sch(dvbdev, bt656, firstfield, buf);
+	else if (bt656->fmode == LINE_SAMPLES) {
+		cxusb_medion_cf_refc_line_smpl(dvbdev, bt656, firstfield,
+					       maxlinesamples, buf);
+		return false;
+	} else if (bt656->fmode == VBI_SAMPLES) {
+		cxusb_medion_cf_refc_vbi_smpl(dvbdev, bt656, buf);
+		return false;
+	}
+
+	return true;
+}
+
+static bool cxusb_medion_cs_start_sch(struct dvb_usb_device *dvbdev,
+				      struct cxusb_medion_auxbuf *auxbuf,
+				      struct cxusb_bt656_params *bt656,
+				      unsigned int maxlinesamples)
+{
+	unsigned char buf[64];
+	unsigned int idx;
+	unsigned int tocheck = clamp_t(size_t, maxlinesamples / 4, 3,
+				       sizeof(buf));
+
+	if (!cxusb_auxbuf_copy(auxbuf, bt656->pos + 1, buf, tocheck))
+		return false;
+
+	for (idx = 0; idx <= tocheck - 3; idx++)
+		if (memcmp(buf + idx, CXUSB_BT656_PREAMBLE, 3) == 0) {
+			bt656->pos += (1 + idx);
+			return true;
+		}
+
+	cxusb_vprintk(dvbdev, BT656, "line %u early start, pos %u\n",
+		      bt656->line, bt656->pos);
+
+	bt656->linesamples = 0;
+	bt656->fmode = LINE_SAMPLES;
+
+	return true;
+}
+
+static void cxusb_medion_cs_line_smpl(struct cxusb_bt656_params *bt656,
+				      unsigned int maxlinesamples,
+				      unsigned char val)
+{
+	if (bt656->buf != NULL)
+		*(bt656->buf++) = val;
+
+	bt656->linesamples++;
+	bt656->pos++;
+
+	if (bt656->linesamples >= maxlinesamples) {
+		bt656->fmode = START_SEARCH;
+		bt656->line++;
+	}
+}
+
+static bool cxusb_medion_copy_samples(struct dvb_usb_device *dvbdev,
+				      struct cxusb_medion_auxbuf *auxbuf,
+				      struct cxusb_bt656_params *bt656,
+				      unsigned int maxlinesamples,
+				      unsigned char val)
+{
+	if (bt656->fmode == START_SEARCH && bt656->line > 0)
+		return cxusb_medion_cs_start_sch(dvbdev, auxbuf, bt656,
+						 maxlinesamples);
+	else if (bt656->fmode == LINE_SAMPLES)
+		cxusb_medion_cs_line_smpl(bt656, maxlinesamples, val);
+	else /* TODO: copy VBI samples */
+		bt656->pos++;
+
+	return true;
+}
+
+static bool cxusb_medion_copy_field(struct dvb_usb_device *dvbdev,
+				    struct cxusb_medion_auxbuf *auxbuf,
+				    struct cxusb_bt656_params *bt656,
+				    bool firstfield,
+				    unsigned int maxlines,
+				    unsigned int maxlinesmpls)
+{
+	while (bt656->line < maxlines) {
+		unsigned char val;
+
+		if (!cxusb_auxbuf_copy(auxbuf, bt656->pos, &val, 1))
+			break;
+
+		if (val == CXUSB_BT656_PREAMBLE[0]) {
+			unsigned char buf[4];
+
+			buf[0] = val;
+			if (!cxusb_auxbuf_copy(auxbuf, bt656->pos + 1,
+					       buf + 1, 3))
+				break;
+
+			if (buf[1] == CXUSB_BT656_PREAMBLE[1] &&
+			    buf[2] == CXUSB_BT656_PREAMBLE[2]) {
+				/*
+				 * is this a field change?
+				 * if so, terminate copying the current field
+				 */
+				if (cxusb_medion_cf_refc_fld_chg(dvbdev,
+								 bt656,
+								 firstfield,
+								 maxlines,
+								 maxlinesmpls,
+								 buf))
+					return true;
+
+				if (cxusb_medion_cf_ref_code(dvbdev, bt656,
+							     firstfield,
+							     maxlines,
+							     maxlinesmpls,
+							     buf))
+					bt656->pos += 4;
+
+				continue;
+			}
+		}
+
+		if (!cxusb_medion_copy_samples(dvbdev, auxbuf, bt656,
+					       maxlinesmpls, val))
+			break;
+	}
+
+	if (bt656->line < maxlines) {
+		cxusb_vprintk(dvbdev, BT656,
+			      "end of buffer pos = %u, line = %u\n",
+			      bt656->pos, bt656->line);
+		return false;
+	}
+
+	return true;
+}
+
+static bool cxusb_medion_v_process_auxbuf(struct cxusb_medion_dev *cxdev,
+					  bool reset)
+{
+	struct dvb_usb_device *dvbdev = cxdev->dvbdev;
+	struct cxusb_bt656_params *bt656 = &cxdev->bt656;
+
+	/*
+	 * if this is a new frame
+	 * fetch a buffer from list
+	 */
+	if (bt656->mode == NEW_FRAME) {
+		if (!list_empty(&cxdev->buflist)) {
+			cxdev->vbuf =
+				list_first_entry(&cxdev->buflist,
+						 struct cxusb_medion_vbuffer,
+						 list);
+			list_del(&cxdev->vbuf->list);
+		} else
+			dev_warn(&dvbdev->udev->dev, "no free buffers\n");
+	}
+
+	if (bt656->mode == NEW_FRAME || reset) {
+		cxusb_vprintk(dvbdev, URB, "will copy field 1\n");
+		bt656->pos = 0;
+		bt656->mode = FIRST_FIELD;
+		bt656->fmode = START_SEARCH;
+		bt656->line = 0;
+
+		if (cxdev->vbuf != NULL) {
+			cxdev->vbuf->vb2.vb2_buf.timestamp = ktime_get_ns();
+			bt656->buf = vb2_plane_vaddr(&cxdev->vbuf->vb2.vb2_buf,
+						     0);
+		}
+	}
+
+	if (bt656->mode == FIRST_FIELD) {
+		if (!cxusb_medion_copy_field(dvbdev, &cxdev->auxbuf, bt656,
+					     true, cxdev->height / 2,
+					     cxdev->width * 2))
+			return false;
+
+		/*
+		 * do not trim buffer there in case
+		 * we need to reset the search later
+		 */
+
+		cxusb_vprintk(dvbdev, URB, "will copy field 2\n");
+		bt656->mode = SECOND_FIELD;
+		bt656->fmode = START_SEARCH;
+		bt656->line = 0;
+	}
+
+	if (bt656->mode == SECOND_FIELD) {
+		if (!cxusb_medion_copy_field(dvbdev, &cxdev->auxbuf, bt656,
+					     false, cxdev->height / 2,
+					     cxdev->width * 2))
+			return false;
+
+		cxusb_auxbuf_head_trim(dvbdev, &cxdev->auxbuf, bt656->pos);
+
+		bt656->mode = NEW_FRAME;
+
+		if (cxdev->vbuf != NULL) {
+			vb2_set_plane_payload(&cxdev->vbuf->vb2.vb2_buf, 0,
+					      cxdev->width * cxdev->height * 2);
+
+			cxdev->vbuf->vb2.field = cxdev->field_order;
+			cxdev->vbuf->vb2.sequence = cxdev->vbuf_sequence++;
+
+			vb2_buffer_done(&cxdev->vbuf->vb2.vb2_buf,
+					VB2_BUF_STATE_DONE);
+
+			cxdev->vbuf = NULL;
+			cxdev->bt656.buf = NULL;
+
+			cxusb_vprintk(dvbdev, URB, "frame done\n");
+		} else {
+			cxusb_vprintk(dvbdev, URB, "frame skipped\n");
+			cxdev->vbuf_sequence++;
+		}
+	}
+
+	return true;
+}
+
+static bool cxusb_medion_v_complete_handle_urb(struct cxusb_medion_dev *cxdev,
+					       bool *auxbuf_reset)
+{
+	struct dvb_usb_device *dvbdev = cxdev->dvbdev;
+	unsigned int urbn;
+	struct urb *urb;
+	int ret;
+
+	*auxbuf_reset = false;
+
+	urbn = cxdev->nexturb;
+	if (!test_bit(urbn, &cxdev->urbcomplete))
+		return false;
+
+	clear_bit(urbn, &cxdev->urbcomplete);
+
+	do {
+		cxdev->nexturb++;
+		cxdev->nexturb %= CXUSB_VIDEO_URBS;
+		urb = cxdev->streamurbs[cxdev->nexturb];
+	} while (urb == NULL);
+
+	urb = cxdev->streamurbs[urbn];
+	cxusb_vprintk(dvbdev, URB, "URB %u status = %d\n", urbn, urb->status);
+
+	if (urb->status == 0 || urb->status == -EXDEV) {
+		int i;
+		unsigned long len;
+
+		for (i = 0, len = 0; i < urb->number_of_packets; i++)
+			len += urb->iso_frame_desc[i].actual_length;
+
+		cxusb_vprintk(dvbdev, URB, "URB %u data len = %lu\n", urbn,
+			      len);
+
+		if (len > 0) {
+			cxusb_vprintk(dvbdev, URB, "appending URB\n");
+
+			/*
+			 * append new data to auxbuf while
+			 * overwriting old data if necessary
+			 *
+			 * if any overwrite happens then we can no
+			 * longer rely on consistency of the whole
+			 * data so let's start again the current
+			 * auxbuf frame assembling process from
+			 * the beginning
+			 */
+			*auxbuf_reset =
+				!cxusb_auxbuf_append_urb(dvbdev,
+							 &cxdev->auxbuf,
+							 urb);
+		}
+	}
+
+	cxusb_vprintk(dvbdev, URB, "URB %u resubmit\n", urbn);
+
+	ret = usb_submit_urb(urb, GFP_KERNEL);
+	if (ret != 0)
+		dev_err(&dvbdev->udev->dev,
+			"unable to resubmit URB %u (%d), you'll have to restart streaming\n",
+			urbn, ret);
+
+	/* next URB is complete already? reschedule us then to handle it */
+	return test_bit(cxdev->nexturb, &cxdev->urbcomplete);
+}
+
+static void cxusb_medion_v_complete_work(struct work_struct *work)
+{
+	struct cxusb_medion_dev *cxdev = container_of(work,
+						      struct cxusb_medion_dev,
+						      urbwork);
+	struct dvb_usb_device *dvbdev = cxdev->dvbdev;
+	bool auxbuf_reset;
+	bool reschedule;
+
+	mutex_lock(cxdev->videodev->lock);
+
+	cxusb_vprintk(dvbdev, URB, "worker called, stop_streaming = %d\n",
+		      (int)cxdev->stop_streaming);
+
+	if (cxdev->stop_streaming)
+		goto unlock;
+
+	reschedule = cxusb_medion_v_complete_handle_urb(cxdev, &auxbuf_reset);
+
+	if (cxusb_medion_v_process_auxbuf(cxdev, auxbuf_reset))
+		/* reschedule us until auxbuf no longer can produce any frame */
+		reschedule = true;
+
+	if (reschedule) {
+		cxusb_vprintk(dvbdev, URB, "rescheduling worker\n");
+		schedule_work(&cxdev->urbwork);
+	}
+
+unlock:
+	mutex_unlock(cxdev->videodev->lock);
+}
+
+static void cxusb_medion_v_complete(struct urb *u)
+{
+	struct dvb_usb_device *dvbdev = u->context;
+	struct cxusb_medion_dev *cxdev = dvbdev->priv;
+	unsigned int i;
+
+	for (i = 0; i < CXUSB_VIDEO_URBS; i++)
+		if (cxdev->streamurbs[i] == u)
+			break;
+
+	if (i >= CXUSB_VIDEO_URBS) {
+		dev_err(&dvbdev->udev->dev,
+			"complete on unknown URB\n");
+		return;
+	}
+
+	cxusb_vprintk(dvbdev, URB, "URB %u complete\n", i);
+
+	set_bit(i, &cxdev->urbcomplete);
+	schedule_work(&cxdev->urbwork);
+}
+
+static void cxusb_medion_urbs_free(struct cxusb_medion_dev *cxdev)
+{
+	unsigned int i;
+
+	for (i = 0; i < CXUSB_VIDEO_URBS; i++)
+		if (cxdev->streamurbs[i] != NULL) {
+			kfree(cxdev->streamurbs[i]->transfer_buffer);
+			usb_free_urb(cxdev->streamurbs[i]);
+			cxdev->streamurbs[i] = NULL;
+		}
+}
+
+static void cxusb_medion_return_buffers(struct cxusb_medion_dev *cxdev,
+					bool requeue)
+{
+	struct cxusb_medion_vbuffer *vbuf, *vbuf_tmp;
+
+	list_for_each_entry_safe(vbuf, vbuf_tmp, &cxdev->buflist,
+				 list) {
+		list_del(&vbuf->list);
+		vb2_buffer_done(&vbuf->vb2.vb2_buf,
+				requeue ? VB2_BUF_STATE_QUEUED :
+				VB2_BUF_STATE_ERROR);
+	}
+
+	if (cxdev->vbuf != NULL) {
+		vb2_buffer_done(&cxdev->vbuf->vb2.vb2_buf,
+				requeue ? VB2_BUF_STATE_QUEUED :
+				VB2_BUF_STATE_ERROR);
+
+		cxdev->vbuf = NULL;
+		cxdev->bt656.buf = NULL;
+	}
+}
+
+static int cxusb_medion_v_ss_auxbuf_alloc(struct cxusb_medion_dev *cxdev,
+					  int *npackets)
+{
+	struct dvb_usb_device *dvbdev = cxdev->dvbdev;
+	u8 *buf;
+	unsigned int framelen, urblen, auxbuflen;
+
+	framelen = (cxdev->width * 2 + 4 + 4) *
+		(cxdev->height + 50 /* VBI lines */);
+
+	/*
+	 * try to fit a whole frame into each URB, as long as doing so
+	 * does not require very high order memory allocations
+	 */
+	BUILD_BUG_ON(CXUSB_VIDEO_URB_MAX_SIZE / CXUSB_VIDEO_PKT_SIZE >
+		     CXUSB_VIDEO_MAX_FRAME_PKTS);
+	*npackets = min_t(int, (framelen + CXUSB_VIDEO_PKT_SIZE - 1) /
+			  CXUSB_VIDEO_PKT_SIZE,
+			  CXUSB_VIDEO_URB_MAX_SIZE / CXUSB_VIDEO_PKT_SIZE);
+	urblen = *npackets * CXUSB_VIDEO_PKT_SIZE;
+
+	cxusb_vprintk(dvbdev, URB,
+		      "each URB will have %d packets for total of %u bytes (%u x %u @ %u)\n",
+		      *npackets, urblen, (unsigned int)cxdev->width,
+		      (unsigned int)cxdev->height, framelen);
+
+	auxbuflen = framelen + urblen;
+
+	buf = vmalloc(auxbuflen);
+	if (buf == NULL)
+		return -ENOMEM;
+
+	cxusb_auxbuf_init(dvbdev, &cxdev->auxbuf, buf, auxbuflen);
+
+	return 0;
+}
+
+static u32 cxusb_medion_norm2field_order(v4l2_std_id norm)
+{
+	bool is625 = norm & V4L2_STD_625_50;
+	bool is525 = norm & V4L2_STD_525_60;
+
+	if (!is625 && !is525)
+		return V4L2_FIELD_NONE;
+
+	if (is625 && is525)
+		return V4L2_FIELD_NONE;
+
+	if (is625)
+		return V4L2_FIELD_SEQ_TB;
+	else /* is525 */
+		return V4L2_FIELD_SEQ_BT;
+}
+
+static u32 cxusb_medion_field_order(struct cxusb_medion_dev *cxdev)
+{
+	struct dvb_usb_device *dvbdev = cxdev->dvbdev;
+	u32 field;
+	int ret;
+	v4l2_std_id norm;
+
+	/* TV tuner is PAL-only so it is always TB */
+	if (cxdev->input == 0)
+		return V4L2_FIELD_SEQ_TB;
+
+	field = cxusb_medion_norm2field_order(cxdev->norm);
+	if (field != V4L2_FIELD_NONE)
+		return field;
+
+	ret = v4l2_subdev_call(cxdev->cx25840, video, g_std, &norm);
+	if (ret != 0)
+		cxusb_vprintk(dvbdev, OPS,
+			      "cannot get current standard for input %u\n",
+			      (unsigned int)cxdev->input);
+	else {
+		field = cxusb_medion_norm2field_order(norm);
+		if (field != V4L2_FIELD_NONE)
+			return field;
+	}
+
+	dev_warn(&dvbdev->udev->dev,
+		 "cannot determine field order for the current standard setup and received signal, using TB\n");
+	return V4L2_FIELD_SEQ_TB;
+}
+
+static int cxusb_medion_v_start_streaming(struct vb2_queue *q,
+					  unsigned int count)
+{
+	struct dvb_usb_device *dvbdev = vb2_get_drv_priv(q);
+	struct cxusb_medion_dev *cxdev = dvbdev->priv;
+	u8 streamon_params[2] = { 0x03, 0x00 };
+	int npackets, i;
+	int ret;
+
+	cxusb_vprintk(dvbdev, OPS, "should start streaming\n");
+
+	if (cxdev->stop_streaming) {
+		/* stream is being stopped */
+		ret = -EBUSY;
+		goto ret_retbufs;
+	}
+
+	cxdev->field_order = cxusb_medion_field_order(cxdev);
+
+	ret = v4l2_subdev_call(cxdev->cx25840, video, s_stream, 1);
+	if (ret != 0) {
+		dev_err(&dvbdev->udev->dev,
+			"unable to start stream (%d)\n", ret);
+		goto ret_retbufs;
+	}
+
+	ret = cxusb_ctrl_msg(dvbdev, CMD_STREAMING_ON, streamon_params, 2,
+			     NULL, 0);
+	if (ret != 0) {
+		dev_err(&dvbdev->udev->dev,
+			"unable to start streaming (%d)\n", ret);
+		goto ret_unstream_cx;
+	}
+
+	ret = cxusb_medion_v_ss_auxbuf_alloc(cxdev, &npackets);
+	if (ret != 0)
+		goto ret_unstream_md;
+
+	for (i = 0; i < CXUSB_VIDEO_URBS; i++) {
+		int framen;
+		u8 *streambuf;
+		struct urb *surb;
+
+		/*
+		 * TODO: change this to an array of single pages to avoid
+		 * doing a large continuous allocation when (if)
+		 * s-g isochronous USB transfers are supported
+		 */
+		streambuf = kmalloc(npackets * CXUSB_VIDEO_PKT_SIZE,
+				    GFP_KERNEL);
+		if (streambuf == NULL) {
+			if (i < 2) {
+				ret = -ENOMEM;
+				goto ret_freeab;
+			} else
+				break;
+		}
+
+		surb = usb_alloc_urb(npackets, GFP_KERNEL);
+		if (surb == NULL) {
+			kfree(streambuf);
+			ret = -ENOMEM;
+			goto ret_freeu;
+		}
+
+		cxdev->streamurbs[i] = surb;
+		surb->dev = dvbdev->udev;
+		surb->context = dvbdev;
+		surb->pipe = usb_rcvisocpipe(dvbdev->udev, 2);
+
+		surb->interval = 1;
+		surb->transfer_flags = URB_ISO_ASAP;
+
+		surb->transfer_buffer = streambuf;
+
+		surb->complete = cxusb_medion_v_complete;
+		surb->number_of_packets = npackets;
+		surb->transfer_buffer_length = npackets * CXUSB_VIDEO_PKT_SIZE;
+
+		for (framen = 0; framen < npackets; framen++) {
+			surb->iso_frame_desc[framen].offset =
+				CXUSB_VIDEO_PKT_SIZE * framen;
+
+			surb->iso_frame_desc[framen].length =
+				CXUSB_VIDEO_PKT_SIZE;
+		}
+	}
+
+	cxdev->urbcomplete = 0;
+	cxdev->nexturb = 0;
+	cxdev->vbuf_sequence = 0;
+
+	cxdev->vbuf = NULL;
+	cxdev->bt656.mode = NEW_FRAME;
+	cxdev->bt656.buf = NULL;
+
+	for (i = 0; i < CXUSB_VIDEO_URBS; i++)
+		if (cxdev->streamurbs[i] != NULL) {
+			ret = usb_submit_urb(cxdev->streamurbs[i],
+					GFP_KERNEL);
+			if (ret != 0)
+				dev_err(&dvbdev->udev->dev,
+					"URB %d submission failed (%d)\n", i,
+					ret);
+		}
+
+	return 0;
+
+ret_freeu:
+	cxusb_medion_urbs_free(cxdev);
+
+ret_freeab:
+	vfree(cxdev->auxbuf.buf);
+
+ret_unstream_md:
+	cxusb_ctrl_msg(dvbdev, CMD_STREAMING_OFF, NULL, 0, NULL, 0);
+
+ret_unstream_cx:
+	v4l2_subdev_call(cxdev->cx25840, video, s_stream, 0);
+
+ret_retbufs:
+	cxusb_medion_return_buffers(cxdev, true);
+
+	return ret;
+}
+
+static void cxusb_medion_v_stop_streaming(struct vb2_queue *q)
+{
+	struct dvb_usb_device *dvbdev = vb2_get_drv_priv(q);
+	struct cxusb_medion_dev *cxdev = dvbdev->priv;
+	int ret;
+	unsigned int i;
+
+	cxusb_vprintk(dvbdev, OPS, "should stop streaming\n");
+
+	if (WARN_ON(cxdev->stop_streaming))
+		return;
+
+	cxdev->stop_streaming = true;
+
+	cxusb_ctrl_msg(dvbdev, CMD_STREAMING_OFF, NULL, 0, NULL, 0);
+
+	ret = v4l2_subdev_call(cxdev->cx25840, video, s_stream, 0);
+	if (ret != 0)
+		dev_err(&dvbdev->udev->dev, "unable to stop stream (%d)\n",
+			ret);
+
+	/* let URB completion run */
+	mutex_unlock(cxdev->videodev->lock);
+
+	for (i = 0; i < CXUSB_VIDEO_URBS; i++)
+		if (cxdev->streamurbs[i] != NULL)
+			usb_kill_urb(cxdev->streamurbs[i]);
+
+	flush_work(&cxdev->urbwork);
+
+	mutex_lock(cxdev->videodev->lock);
+
+	/* free transfer buffer and URB */
+	vfree(cxdev->auxbuf.buf);
+
+	cxusb_medion_urbs_free(cxdev);
+
+	cxusb_medion_return_buffers(cxdev, false);
+
+	cxdev->stop_streaming = false;
+}
+
+static void cxusub_medion_v_buf_queue(struct vb2_buffer *vb)
+{
+	struct vb2_v4l2_buffer *v4l2buf = to_vb2_v4l2_buffer(vb);
+	struct cxusb_medion_vbuffer *vbuf =
+		container_of(v4l2buf, struct cxusb_medion_vbuffer, vb2);
+	struct dvb_usb_device *dvbdev = vb2_get_drv_priv(vb->vb2_queue);
+	struct cxusb_medion_dev *cxdev = dvbdev->priv;
+
+	/* cxusb_vprintk(dvbdev, OPS, "mmmm.. a fresh buffer...\n"); */
+
+	list_add_tail(&vbuf->list, &cxdev->buflist);
+}
+
+static const struct vb2_ops cxdev_video_qops = {
+	.queue_setup = cxusb_medion_v_queue_setup,
+	.buf_init = cxusb_medion_v_buf_init,
+	.start_streaming = cxusb_medion_v_start_streaming,
+	.stop_streaming = cxusb_medion_v_stop_streaming,
+	.buf_queue = cxusub_medion_v_buf_queue,
+	.wait_prepare = vb2_ops_wait_prepare,
+	.wait_finish = vb2_ops_wait_finish
+};
+
+static const __u32 videocaps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_TUNER |
+	V4L2_CAP_READWRITE | V4L2_CAP_STREAMING;
+static const __u32 radiocaps = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
+
+static int cxusb_medion_v_querycap(struct file *file, void *fh,
+				   struct v4l2_capability *cap)
+{
+	struct dvb_usb_device *dvbdev = video_drvdata(file);
+
+	strscpy(cap->driver, dvbdev->udev->dev.driver->name,
+		sizeof(cap->driver));
+	strscpy(cap->card, "Medion 95700", sizeof(cap->card));
+	usb_make_path(dvbdev->udev, cap->bus_info, sizeof(cap->bus_info));
+
+	cap->capabilities = videocaps | radiocaps | V4L2_CAP_DEVICE_CAPS;
+
+	return 0;
+}
+
+static int cxusb_medion_v_enum_fmt_vid_cap(struct file *file, void *fh,
+					   struct v4l2_fmtdesc *f)
+{
+	if (f->index != 0)
+		return -EINVAL;
+
+	f->pixelformat = V4L2_PIX_FMT_UYVY;
+
+	return 0;
+}
+
+static int cxusb_medion_g_fmt_vid_cap(struct file *file, void *fh,
+				      struct v4l2_format *f)
+{
+	struct dvb_usb_device *dvbdev = video_drvdata(file);
+	struct cxusb_medion_dev *cxdev = dvbdev->priv;
+
+	f->fmt.pix.width = cxdev->width;
+	f->fmt.pix.height = cxdev->height;
+	f->fmt.pix.pixelformat = V4L2_PIX_FMT_UYVY;
+	f->fmt.pix.field = vb2_start_streaming_called(&cxdev->videoqueue) ?
+		cxdev->field_order : cxusb_medion_field_order(cxdev);
+	f->fmt.pix.bytesperline = cxdev->width * 2;
+	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
+	f->fmt.pix.sizeimage = f->fmt.pix.bytesperline * f->fmt.pix.height;
+
+	return 0;
+}
+
+static int cxusb_medion_try_s_fmt_vid_cap(struct file *file,
+					  struct v4l2_format *f,
+					  bool isset)
+{
+	struct dvb_usb_device *dvbdev = video_drvdata(file);
+	struct cxusb_medion_dev *cxdev = dvbdev->priv;
+	struct v4l2_subdev_format subfmt;
+	u32 field;
+	int ret;
+
+	if (isset && vb2_is_busy(&cxdev->videoqueue))
+		return -EBUSY;
+
+	field = vb2_start_streaming_called(&cxdev->videoqueue) ?
+		cxdev->field_order : cxusb_medion_field_order(cxdev);
+
+	memset(&subfmt, 0, sizeof(subfmt));
+	subfmt.which = isset ? V4L2_SUBDEV_FORMAT_ACTIVE :
+		V4L2_SUBDEV_FORMAT_TRY;
+	subfmt.format.width = f->fmt.pix.width & ~1;
+	subfmt.format.height = f->fmt.pix.height & ~1;
+	subfmt.format.code = MEDIA_BUS_FMT_FIXED;
+	subfmt.format.field = field;
+	subfmt.format.colorspace = V4L2_COLORSPACE_SMPTE170M;
+
+	ret = v4l2_subdev_call(cxdev->cx25840, pad, set_fmt, NULL, &subfmt);
+	if (ret != 0)
+		return ret;
+
+	f->fmt.pix.width = subfmt.format.width;
+	f->fmt.pix.height = subfmt.format.height;
+	f->fmt.pix.pixelformat = V4L2_PIX_FMT_UYVY;
+	f->fmt.pix.field = field;
+	f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
+	f->fmt.pix.sizeimage = f->fmt.pix.bytesperline * f->fmt.pix.height;
+	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
+
+	if (isset) {
+		cxdev->width = f->fmt.pix.width;
+		cxdev->height = f->fmt.pix.height;
+	}
+
+	return 0;
+}
+
+static int cxusb_medion_try_fmt_vid_cap(struct file *file, void *fh,
+					struct v4l2_format *f)
+{
+	return cxusb_medion_try_s_fmt_vid_cap(file, f, false);
+}
+
+static int cxusb_medion_s_fmt_vid_cap(struct file *file, void *fh,
+				      struct v4l2_format *f)
+{
+	return cxusb_medion_try_s_fmt_vid_cap(file, f, true);
+}
+
+static const struct {
+	struct v4l2_input input;
+	u32 inputcfg;
+} cxusb_medion_inputs[] = {
+	{ .input = { .name = "TV tuner", .type = V4L2_INPUT_TYPE_TUNER,
+		     .tuner = 0, .std = V4L2_STD_PAL },
+	  .inputcfg = CX25840_COMPOSITE2, },
+
+	{  .input = { .name = "Composite", .type = V4L2_INPUT_TYPE_CAMERA,
+		     .std = V4L2_STD_ALL },
+	   .inputcfg = CX25840_COMPOSITE1, },
+
+	{  .input = { .name = "S-Video", .type = V4L2_INPUT_TYPE_CAMERA,
+		      .std = V4L2_STD_ALL },
+