diff mbox

[REVIEW,01/86] rtl2832_sdr: Realtek RTL2832 SDR driver module

Message ID 1391935771-18670-2-git-send-email-crope@iki.fi (mailing list archive)
State New, archived
Headers show

Commit Message

Antti Palosaari Feb. 9, 2014, 8:48 a.m. UTC
Implement SDR driver for Realtek RTL2832U chip as a DVB extension
module. SDR module is attached by DVB USB RTL28XXU driver as a DVB
SEC (satellite equipment controller) module. Abusing unused SEC here
has no harm as that is DVB-T only frontend.

SDR functionality is provided by RTL2832 DVB-T demodulator. I suspect
it is originally planned for DAB and FM, but it could be abused general
SDR, due to modern silicon tuners that has wide frequency range and a
lot of configurable parameters (filters, gains, ...).

http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/44461

Signed-off-by: Antti Palosaari <crope@iki.fi>
---
 drivers/staging/media/Kconfig                    |    2 +
 drivers/staging/media/Makefile                   |    2 +
 drivers/staging/media/rtl2832u_sdr/Kconfig       |    7 +
 drivers/staging/media/rtl2832u_sdr/Makefile      |    4 +
 drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c | 1184 ++++++++++++++++++++++
 drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.h |   52 +
 6 files changed, 1251 insertions(+)
 create mode 100644 drivers/staging/media/rtl2832u_sdr/Kconfig
 create mode 100644 drivers/staging/media/rtl2832u_sdr/Makefile
 create mode 100644 drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c
 create mode 100644 drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.h
diff mbox

Patch

diff --git a/drivers/staging/media/Kconfig b/drivers/staging/media/Kconfig
index 22b0c9d..a9f2e63 100644
--- a/drivers/staging/media/Kconfig
+++ b/drivers/staging/media/Kconfig
@@ -41,6 +41,8 @@  source "drivers/staging/media/solo6x10/Kconfig"
 
 source "drivers/staging/media/omap4iss/Kconfig"
 
+source "drivers/staging/media/rtl2832u_sdr/Kconfig"
+
 # Keep LIRC at the end, as it has sub-menus
 source "drivers/staging/media/lirc/Kconfig"
 
diff --git a/drivers/staging/media/Makefile b/drivers/staging/media/Makefile
index bedc62a..8e2c5d2 100644
--- a/drivers/staging/media/Makefile
+++ b/drivers/staging/media/Makefile
@@ -11,3 +11,5 @@  obj-$(CONFIG_VIDEO_OMAP4)	+= omap4iss/
 obj-$(CONFIG_USB_SN9C102)       += sn9c102/
 obj-$(CONFIG_VIDEO_OMAP2)       += omap24xx/
 obj-$(CONFIG_VIDEO_TCM825X)     += omap24xx/
+obj-$(CONFIG_DVB_RTL2832_SDR)	+= rtl2832u_sdr/
+
diff --git a/drivers/staging/media/rtl2832u_sdr/Kconfig b/drivers/staging/media/rtl2832u_sdr/Kconfig
new file mode 100644
index 0000000..3ede5fe
--- /dev/null
+++ b/drivers/staging/media/rtl2832u_sdr/Kconfig
@@ -0,0 +1,7 @@ 
+config DVB_RTL2832_SDR
+	tristate "Realtek RTL2832 SDR"
+	depends on USB && DVB_CORE && I2C && VIDEO_V4L2 && DVB_USB_RTL28XXU
+	select DVB_RTL2832
+	select VIDEOBUF2_VMALLOC
+	default m if !MEDIA_SUBDRV_AUTOSELECT
+
diff --git a/drivers/staging/media/rtl2832u_sdr/Makefile b/drivers/staging/media/rtl2832u_sdr/Makefile
new file mode 100644
index 0000000..684546776
--- /dev/null
+++ b/drivers/staging/media/rtl2832u_sdr/Makefile
@@ -0,0 +1,4 @@ 
+obj-$(CONFIG_DVB_RTL2832_SDR) += rtl2832_sdr.o
+
+ccflags-y += -Idrivers/media/dvb-core
+ccflags-y += -Idrivers/media/usb/dvb-usb-v2
diff --git a/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c b/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c
new file mode 100644
index 0000000..0b110a3
--- /dev/null
+++ b/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c
@@ -0,0 +1,1184 @@ 
+/*
+ * Realtek RTL2832U SDR driver
+ *
+ * Copyright (C) 2013 Antti Palosaari <crope@iki.fi>
+ *
+ *    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.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License along
+ *    with this program; if not, write to the Free Software Foundation, Inc.,
+ *    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * GNU Radio plugin "gr-kernel" for device usage will be on:
+ * http://git.linuxtv.org/anttip/gr-kernel.git
+ *
+ * TODO:
+ * Help is very highly welcome for these + all the others you could imagine:
+ * - move controls to V4L2 API
+ * - use libv4l2 for stream format conversions
+ * - gr-kernel: switch to v4l2_mmap (current read eats a lot of cpu)
+ * - SDRSharp support
+ */
+
+#include "dvb_frontend.h"
+#include "rtl2832_sdr.h"
+#include "dvb_usb.h"
+
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-event.h>
+#include <media/videobuf2-vmalloc.h>
+
+/* TODO: These should be moved to V4L2 API */
+#define RTL2832_SDR_CID_SAMPLING_MODE       ((V4L2_CID_USER_BASE | 0xf000) +  0)
+#define RTL2832_SDR_CID_SAMPLING_RATE       ((V4L2_CID_USER_BASE | 0xf000) +  1)
+#define RTL2832_SDR_CID_SAMPLING_RESOLUTION ((V4L2_CID_USER_BASE | 0xf000) +  2)
+#define RTL2832_SDR_CID_TUNER_RF            ((V4L2_CID_USER_BASE | 0xf000) + 10)
+#define RTL2832_SDR_CID_TUNER_BW            ((V4L2_CID_USER_BASE | 0xf000) + 11)
+#define RTL2832_SDR_CID_TUNER_IF            ((V4L2_CID_USER_BASE | 0xf000) + 12)
+#define RTL2832_SDR_CID_TUNER_GAIN          ((V4L2_CID_USER_BASE | 0xf000) + 13)
+
+#define MAX_BULK_BUFS            (8)
+#define BULK_BUFFER_SIZE         (8 * 512)
+
+/* intermediate buffers with raw data from the USB device */
+struct rtl2832_sdr_frame_buf {
+	struct vb2_buffer vb;   /* common v4l buffer stuff -- must be first */
+	struct list_head list;
+};
+
+struct rtl2832_sdr_state {
+#define POWER_ON           (1 << 1)
+#define URB_BUF            (1 << 2)
+	unsigned long flags;
+
+	const struct rtl2832_sdr_config *cfg;
+	struct dvb_frontend *fe;
+	struct dvb_usb_device *d;
+	struct i2c_adapter *i2c;
+	u8 bank;
+
+	struct video_device vdev;
+	struct v4l2_device v4l2_dev;
+
+	/* videobuf2 queue and queued buffers list */
+	struct vb2_queue vb_queue;
+	struct list_head queued_bufs;
+	spinlock_t queued_bufs_lock; /* Protects queued_bufs */
+
+	/* Note if taking both locks v4l2_lock must always be locked first! */
+	struct mutex v4l2_lock;      /* Protects everything else */
+	struct mutex vb_queue_lock;  /* Protects vb_queue and capt_file */
+
+	/* Pointer to our usb_device, will be NULL after unplug */
+	struct usb_device *udev; /* Both mutexes most be hold when setting! */
+
+	unsigned int vb_full; /* vb is full and packets dropped */
+
+	struct urb     *urb_list[MAX_BULK_BUFS];
+	int            buf_num;
+	unsigned long  buf_size;
+	u8             *buf_list[MAX_BULK_BUFS];
+	dma_addr_t     dma_addr[MAX_BULK_BUFS];
+	int urbs_initialized;
+	int urbs_submitted;
+
+	/* Controls */
+	struct v4l2_ctrl_handler ctrl_handler;
+	struct v4l2_ctrl *ctrl_sampling_rate;
+	struct v4l2_ctrl *ctrl_tuner_rf;
+	struct v4l2_ctrl *ctrl_tuner_bw;
+	struct v4l2_ctrl *ctrl_tuner_if;
+	struct v4l2_ctrl *ctrl_tuner_gain;
+
+	/* for sample rate calc */
+	unsigned int sample;
+	unsigned int sample_measured;
+	unsigned long jiffies;
+};
+
+/* write multiple hardware registers */
+static int rtl2832_sdr_wr(struct rtl2832_sdr_state *s, u8 reg, const u8 *val,
+		int len)
+{
+	int ret;
+	u8 buf[1 + len];
+	struct i2c_msg msg[1] = {
+		{
+			.addr = s->cfg->i2c_addr,
+			.flags = 0,
+			.len = 1 + len,
+			.buf = buf,
+		}
+	};
+
+	buf[0] = reg;
+	memcpy(&buf[1], val, len);
+
+	ret = i2c_transfer(s->i2c, msg, 1);
+	if (ret == 1) {
+		ret = 0;
+	} else {
+		dev_err(&s->i2c->dev,
+			"%s: I2C wr failed=%d reg=%02x len=%d\n",
+			KBUILD_MODNAME, ret, reg, len);
+		ret = -EREMOTEIO;
+	}
+	return ret;
+}
+
+#if 0
+/* read multiple hardware registers */
+static int rtl2832_sdr_rd(struct rtl2832_sdr_state *s, u8 reg, u8 *val, int len)
+{
+	int ret;
+	struct i2c_msg msg[2] = {
+		{
+			.addr = s->cfg->i2c_addr,
+			.flags = 0,
+			.len = 1,
+			.buf = &reg,
+		}, {
+			.addr = s->cfg->i2c_addr,
+			.flags = I2C_M_RD,
+			.len = len,
+			.buf = val,
+		}
+	};
+
+	ret = i2c_transfer(s->i2c, msg, 2);
+	if (ret == 2) {
+		ret = 0;
+	} else {
+		dev_err(&s->i2c->dev,
+				"%s: I2C rd failed=%d reg=%02x len=%d\n",
+				KBUILD_MODNAME, ret, reg, len);
+		ret = -EREMOTEIO;
+	}
+	return ret;
+}
+#endif
+
+/* write multiple registers */
+static int rtl2832_sdr_wr_regs(struct rtl2832_sdr_state *s, u16 reg,
+		const u8 *val, int len)
+{
+	int ret;
+	u8 reg2 = (reg >> 0) & 0xff;
+	u8 bank = (reg >> 8) & 0xff;
+
+	/* switch bank if needed */
+	if (bank != s->bank) {
+		ret = rtl2832_sdr_wr(s, 0x00, &bank, 1);
+		if (ret)
+			return ret;
+
+		s->bank = bank;
+	}
+
+	return rtl2832_sdr_wr(s, reg2, val, len);
+}
+
+#if 0
+/* read multiple registers */
+static int rtl2832_sdr_rd_regs(struct rtl2832_sdr_state *s, u16 reg, u8 *val,
+		int len)
+{
+	int ret;
+	u8 reg2 = (reg >> 0) & 0xff;
+	u8 bank = (reg >> 8) & 0xff;
+
+	/* switch bank if needed */
+	if (bank != s->bank) {
+		ret = rtl2832_sdr_wr(s, 0x00, &bank, 1);
+		if (ret)
+			return ret;
+
+		s->bank = bank;
+	}
+
+	return rtl2832_sdr_rd(s, reg2, val, len);
+}
+
+/* read single register */
+static int rtl2832_sdr_rd_reg(struct rtl2832_sdr_state *s, u16 reg, u8 *val)
+{
+	return rtl2832_sdr_rd_regs(s, reg, val, 1);
+}
+
+/* write single register with mask */
+static int rtl2832_sdr_wr_reg_mask(struct rtl2832_sdr_state *s, u16 reg,
+		u8 val, u8 mask)
+{
+	int ret;
+	u8 tmp;
+
+	/* no need for read if whole reg is written */
+	if (mask != 0xff) {
+		ret = rtl2832_sdr_rd_regs(s, reg, &tmp, 1);
+		if (ret)
+			return ret;
+
+		val &= mask;
+		tmp &= ~mask;
+		val |= tmp;
+	}
+
+	return rtl2832_sdr_wr_regs(s, reg, &val, 1);
+}
+
+/* read single register with mask */
+static int rtl2832_sdr_rd_reg_mask(struct rtl2832_sdr_state *s, u16 reg,
+		u8 *val, u8 mask)
+{
+	int ret, i;
+	u8 tmp;
+
+	ret = rtl2832_sdr_rd_regs(s, reg, &tmp, 1);
+	if (ret)
+		return ret;
+
+	tmp &= mask;
+
+	/* find position of the first bit */
+	for (i = 0; i < 8; i++) {
+		if ((mask >> i) & 0x01)
+			break;
+	}
+	*val = tmp >> i;
+
+	return 0;
+}
+#endif
+
+/* Private functions */
+static struct rtl2832_sdr_frame_buf *rtl2832_sdr_get_next_fill_buf(
+		struct rtl2832_sdr_state *s)
+{
+	unsigned long flags = 0;
+	struct rtl2832_sdr_frame_buf *buf = NULL;
+
+	spin_lock_irqsave(&s->queued_bufs_lock, flags);
+	if (list_empty(&s->queued_bufs))
+		goto leave;
+
+	buf = list_entry(s->queued_bufs.next,
+			struct rtl2832_sdr_frame_buf, list);
+	list_del(&buf->list);
+leave:
+	spin_unlock_irqrestore(&s->queued_bufs_lock, flags);
+	return buf;
+}
+
+/*
+ * Integer to 32-bit IEEE floating point representation routine is taken
+ * from Radeon R600 driver (drivers/gpu/drm/radeon/r600_blit_kms.c).
+ *
+ * TODO: Currently we do conversion here in Kernel, but in future that will
+ * be moved to the libv4l2 library as video format conversions are.
+ */
+#define I2F_FRAC_BITS  23
+#define I2F_MASK ((1 << I2F_FRAC_BITS) - 1)
+
+/*
+ * Converts signed 8-bit integer into 32-bit IEEE floating point
+ * representation.
+ */
+static u32 rtl2832_sdr_convert_sample(struct rtl2832_sdr_state *s, u16 x)
+{
+	u32 msb, exponent, fraction, sign;
+
+	/* Zero is special */
+	if (!x)
+		return 0;
+
+	/* Negative / positive value */
+	if (x & (1 << 7)) {
+		x = -x;
+		x &= 0x7f; /* result is 7 bit ... + sign */
+		sign = 1 << 31;
+	} else {
+		sign = 0 << 31;
+	}
+
+	/* Get location of the most significant bit */
+	msb = __fls(x);
+
+	fraction = ror32(x, (msb - I2F_FRAC_BITS) & 0x1f) & I2F_MASK;
+	exponent = (127 + msb) << I2F_FRAC_BITS;
+
+	return (fraction + exponent) | sign;
+}
+
+static unsigned int rtl2832_sdr_convert_stream(struct rtl2832_sdr_state *s,
+		u32 *dst, const u8 *src, unsigned int src_len)
+{
+	unsigned int i, dst_len = 0;
+
+	for (i = 0; i < src_len; i++)
+		*dst++ = rtl2832_sdr_convert_sample(s, src[i]);
+
+	/* 8-bit to 32-bit IEEE floating point */
+	dst_len = src_len * 4;
+
+	/* calculate samping rate and output it in 10 seconds intervals */
+	if ((s->jiffies + msecs_to_jiffies(10000)) <= jiffies) {
+		unsigned long jiffies_now = jiffies;
+		unsigned long msecs = jiffies_to_msecs(jiffies_now) - jiffies_to_msecs(s->jiffies);
+		unsigned int samples = s->sample - s->sample_measured;
+		s->jiffies = jiffies_now;
+		s->sample_measured = s->sample;
+		dev_dbg(&s->udev->dev,
+				"slen=%d samples=%u msecs=%lu sampling rate=%lu\n",
+				src_len, samples, msecs,
+				samples * 1000UL / msecs);
+	}
+
+	/* total number of I+Q pairs */
+	s->sample += src_len / 2;
+
+	return dst_len;
+}
+
+/*
+ * This gets called for the bulk stream pipe. This is done in interrupt
+ * time, so it has to be fast, not crash, and not stall. Neat.
+ */
+static void rtl2832_sdr_urb_complete(struct urb *urb)
+{
+	struct rtl2832_sdr_state *s = urb->context;
+	struct rtl2832_sdr_frame_buf *fbuf;
+
+	dev_dbg_ratelimited(&s->udev->dev,
+			"%s: status=%d length=%d/%d errors=%d\n",
+			__func__, urb->status, urb->actual_length,
+			urb->transfer_buffer_length, urb->error_count);
+
+	switch (urb->status) {
+	case 0:             /* success */
+	case -ETIMEDOUT:    /* NAK */
+		break;
+	case -ECONNRESET:   /* kill */
+	case -ENOENT:
+	case -ESHUTDOWN:
+		return;
+	default:            /* error */
+		dev_err_ratelimited(&s->udev->dev, "urb failed=%d\n",
+				urb->status);
+		break;
+	}
+
+	if (urb->actual_length > 0) {
+		void *ptr;
+		unsigned int len;
+		/* get free framebuffer */
+		fbuf = rtl2832_sdr_get_next_fill_buf(s);
+		if (fbuf == NULL) {
+			s->vb_full++;
+			dev_notice_ratelimited(&s->udev->dev,
+					"videobuf is full, %d packets dropped\n",
+					s->vb_full);
+			goto skip;
+		}
+
+		/* fill framebuffer */
+		ptr = vb2_plane_vaddr(&fbuf->vb, 0);
+		len = rtl2832_sdr_convert_stream(s, ptr, urb->transfer_buffer,
+				urb->actual_length);
+		vb2_set_plane_payload(&fbuf->vb, 0, len);
+		vb2_buffer_done(&fbuf->vb, VB2_BUF_STATE_DONE);
+	}
+skip:
+	usb_submit_urb(urb, GFP_ATOMIC);
+}
+
+static int rtl2832_sdr_kill_urbs(struct rtl2832_sdr_state *s)
+{
+	int i;
+
+	for (i = s->urbs_submitted - 1; i >= 0; i--) {
+		dev_dbg(&s->udev->dev, "%s: kill urb=%d\n", __func__, i);
+		/* stop the URB */
+		usb_kill_urb(s->urb_list[i]);
+	}
+	s->urbs_submitted = 0;
+
+	return 0;
+}
+
+static int rtl2832_sdr_submit_urbs(struct rtl2832_sdr_state *s)
+{
+	int i, ret;
+
+	for (i = 0; i < s->urbs_initialized; i++) {
+		dev_dbg(&s->udev->dev, "%s: submit urb=%d\n", __func__, i);
+		ret = usb_submit_urb(s->urb_list[i], GFP_ATOMIC);
+		if (ret) {
+			dev_err(&s->udev->dev,
+					"Could not submit urb no. %d - get them all back\n",
+					i);
+			rtl2832_sdr_kill_urbs(s);
+			return ret;
+		}
+		s->urbs_submitted++;
+	}
+
+	return 0;
+}
+
+static int rtl2832_sdr_free_stream_bufs(struct rtl2832_sdr_state *s)
+{
+	if (s->flags & USB_STATE_URB_BUF) {
+		while (s->buf_num) {
+			s->buf_num--;
+			dev_dbg(&s->udev->dev, "%s: free buf=%d\n",
+					__func__, s->buf_num);
+			usb_free_coherent(s->udev, s->buf_size,
+					  s->buf_list[s->buf_num],
+					  s->dma_addr[s->buf_num]);
+		}
+	}
+	s->flags &= ~USB_STATE_URB_BUF;
+
+	return 0;
+}
+
+static int rtl2832_sdr_alloc_stream_bufs(struct rtl2832_sdr_state *s)
+{
+	s->buf_num = 0;
+	s->buf_size = BULK_BUFFER_SIZE;
+
+	dev_dbg(&s->udev->dev,
+			"%s: all in all I will use %u bytes for streaming\n",
+			__func__,  MAX_BULK_BUFS * BULK_BUFFER_SIZE);
+
+	for (s->buf_num = 0; s->buf_num < MAX_BULK_BUFS; s->buf_num++) {
+		s->buf_list[s->buf_num] = usb_alloc_coherent(s->udev,
+				BULK_BUFFER_SIZE, GFP_ATOMIC,
+				&s->dma_addr[s->buf_num]);
+		if (!s->buf_list[s->buf_num]) {
+			dev_dbg(&s->udev->dev, "%s: alloc buf=%d failed\n",
+					__func__, s->buf_num);
+			rtl2832_sdr_free_stream_bufs(s);
+			return -ENOMEM;
+		}
+
+		dev_dbg(&s->udev->dev, "%s: alloc buf=%d %p (dma %llu)\n",
+				__func__, s->buf_num,
+				s->buf_list[s->buf_num],
+				(long long)s->dma_addr[s->buf_num]);
+		s->flags |= USB_STATE_URB_BUF;
+	}
+
+	return 0;
+}
+
+static int rtl2832_sdr_free_urbs(struct rtl2832_sdr_state *s)
+{
+	int i;
+
+	rtl2832_sdr_kill_urbs(s);
+
+	for (i = s->urbs_initialized - 1; i >= 0; i--) {
+		if (s->urb_list[i]) {
+			dev_dbg(&s->udev->dev, "%s: free urb=%d\n",
+					__func__, i);
+			/* free the URBs */
+			usb_free_urb(s->urb_list[i]);
+		}
+	}
+	s->urbs_initialized = 0;
+
+	return 0;
+}
+
+static int rtl2832_sdr_alloc_urbs(struct rtl2832_sdr_state *s)
+{
+	int i, j;
+
+	/* allocate the URBs */
+	for (i = 0; i < MAX_BULK_BUFS; i++) {
+		dev_dbg(&s->udev->dev, "%s: alloc urb=%d\n", __func__, i);
+		s->urb_list[i] = usb_alloc_urb(0, GFP_ATOMIC);
+		if (!s->urb_list[i]) {
+			dev_dbg(&s->udev->dev, "%s: failed\n", __func__);
+			for (j = 0; j < i; j++)
+				usb_free_urb(s->urb_list[j]);
+			return -ENOMEM;
+		}
+		usb_fill_bulk_urb(s->urb_list[i],
+				s->udev,
+				usb_rcvbulkpipe(s->udev, 0x81),
+				s->buf_list[i],
+				BULK_BUFFER_SIZE,
+				rtl2832_sdr_urb_complete, s);
+
+		s->urb_list[i]->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
+		s->urb_list[i]->transfer_dma = s->dma_addr[i];
+		s->urbs_initialized++;
+	}
+
+	return 0;
+}
+
+/* Must be called with vb_queue_lock hold */
+static void rtl2832_sdr_cleanup_queued_bufs(struct rtl2832_sdr_state *s)
+{
+	unsigned long flags = 0;
+	dev_dbg(&s->udev->dev, "%s:\n", __func__);
+
+	spin_lock_irqsave(&s->queued_bufs_lock, flags);
+	while (!list_empty(&s->queued_bufs)) {
+		struct rtl2832_sdr_frame_buf *buf;
+		buf = list_entry(s->queued_bufs.next,
+				struct rtl2832_sdr_frame_buf, list);
+		list_del(&buf->list);
+		vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
+	}
+	spin_unlock_irqrestore(&s->queued_bufs_lock, flags);
+}
+
+/* The user yanked out the cable... */
+static void rtl2832_sdr_release_sec(struct dvb_frontend *fe)
+{
+	struct rtl2832_sdr_state *s = fe->sec_priv;
+	dev_dbg(&s->udev->dev, "%s:\n", __func__);
+
+	mutex_lock(&s->vb_queue_lock);
+	mutex_lock(&s->v4l2_lock);
+	/* No need to keep the urbs around after disconnection */
+	s->udev = NULL;
+
+	v4l2_device_disconnect(&s->v4l2_dev);
+	video_unregister_device(&s->vdev);
+	mutex_unlock(&s->v4l2_lock);
+	mutex_unlock(&s->vb_queue_lock);
+
+	v4l2_device_put(&s->v4l2_dev);
+
+	fe->sec_priv = NULL;
+}
+
+static int rtl2832_sdr_querycap(struct file *file, void *fh,
+		struct v4l2_capability *cap)
+{
+	struct rtl2832_sdr_state *s = video_drvdata(file);
+	dev_dbg(&s->udev->dev, "%s:\n", __func__);
+
+	strlcpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
+	strlcpy(cap->card, s->vdev.name, sizeof(cap->card));
+	usb_make_path(s->udev, cap->bus_info, sizeof(cap->bus_info));
+	cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING |
+			V4L2_CAP_READWRITE;
+	cap->device_caps = V4L2_CAP_TUNER;
+	cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
+	return 0;
+}
+
+/* Videobuf2 operations */
+static int rtl2832_sdr_queue_setup(struct vb2_queue *vq,
+		const struct v4l2_format *fmt, unsigned int *nbuffers,
+		unsigned int *nplanes, unsigned int sizes[], void *alloc_ctxs[])
+{
+	struct rtl2832_sdr_state *s = vb2_get_drv_priv(vq);
+	dev_dbg(&s->udev->dev, "%s: *nbuffers=%d\n", __func__, *nbuffers);
+
+	/* Absolute min and max number of buffers available for mmap() */
+	*nbuffers = 32;
+	*nplanes = 1;
+	sizes[0] = PAGE_ALIGN(BULK_BUFFER_SIZE * 4); /* 8 * 512 * 4 = 16384 */
+	dev_dbg(&s->udev->dev, "%s: nbuffers=%d sizes[0]=%d\n",
+			__func__, *nbuffers, sizes[0]);
+	return 0;
+}
+
+static int rtl2832_sdr_buf_prepare(struct vb2_buffer *vb)
+{
+	struct rtl2832_sdr_state *s = vb2_get_drv_priv(vb->vb2_queue);
+
+	/* Don't allow queing new buffers after device disconnection */
+	if (!s->udev)
+		return -ENODEV;
+
+	return 0;
+}
+
+static void rtl2832_sdr_buf_queue(struct vb2_buffer *vb)
+{
+	struct rtl2832_sdr_state *s = vb2_get_drv_priv(vb->vb2_queue);
+	struct rtl2832_sdr_frame_buf *buf =
+			container_of(vb, struct rtl2832_sdr_frame_buf, vb);
+	unsigned long flags = 0;
+
+	/* Check the device has not disconnected between prep and queuing */
+	if (!s->udev) {
+		vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
+		return;
+	}
+
+	spin_lock_irqsave(&s->queued_bufs_lock, flags);
+	list_add_tail(&buf->list, &s->queued_bufs);
+	spin_unlock_irqrestore(&s->queued_bufs_lock, flags);
+}
+
+static int rtl2832_sdr_set_adc(struct rtl2832_sdr_state *s)
+{
+	int ret;
+	unsigned int f_sr;
+
+	dev_dbg(&s->udev->dev, "%s:\n", __func__);
+
+	if (!test_bit(POWER_ON, &s->flags))
+		return 0;
+
+	f_sr = s->ctrl_sampling_rate->val64;
+
+	ret = rtl2832_sdr_wr_regs(s, 0x13e, "\x00\x00", 2);
+	ret = rtl2832_sdr_wr_regs(s, 0x115, "\x00", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x116, "\x00\x00", 2);
+	ret = rtl2832_sdr_wr_regs(s, 0x118, "\x00", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x119, "\x00\x00", 2);
+	ret = rtl2832_sdr_wr_regs(s, 0x11b, "\x00", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x19f, "\x03\x84", 2);
+	ret = rtl2832_sdr_wr_regs(s, 0x1a1, "\x00\x00", 2);
+	ret = rtl2832_sdr_wr_regs(s, 0x11c, "\xca", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x11d, "\xdc", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x11e, "\xd7", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x11f, "\xd8", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x120, "\xe0", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x121, "\xf2", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x122, "\x0e", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x123, "\x35", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x124, "\x06", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x125, "\x50", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x126, "\x9c", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x127, "\x0d", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x128, "\x71", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x129, "\x11", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x12a, "\x14", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x12b, "\x71", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x12c, "\x74", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x12d, "\x19", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x12e, "\x41", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x12f, "\xa5", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x017, "\x11", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x018, "\x10", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x019, "\x21", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x01f, "\xff", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x01e, "\x01", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x01d, "\x06", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x01c, "\x0d", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x01b, "\x16", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x01a, "\x1b", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x192, "\x00", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x193, "\xf0", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x194, "\x0f", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x061, "\x60", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x006, "\x80", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x112, "\x5a", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x102, "\x40", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x103, "\x5a", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1c7, "\x30", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x104, "\xd0", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x105, "\xbe", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1c8, "\x18", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x106, "\x35", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1c9, "\x21", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1ca, "\x21", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1cb, "\x00", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x107, "\x40", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1cd, "\x10", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1ce, "\x10", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x108, "\x80", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x109, "\x7f", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x10a, "\x80", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x10b, "\x7f", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x00e, "\xfc", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x00e, "\xfc", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x011, "\xd4", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1e5, "\xf0", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1d9, "\x00", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1db, "\x00", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1dd, "\x14", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1de, "\xec", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1d8, "\x0c", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1e6, "\x02", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1d7, "\x09", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x00d, "\x83", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x010, "\x49", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x00d, "\x87", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x00d, "\x85", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x013, "\x02", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x008, "\xcd", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x1b1, "\x01", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x101, "\x14", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x101, "\x10", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x019, "\x21", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x10c, "\x00", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x101, "\x14", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x101, "\x10", 1);
+	ret = rtl2832_sdr_wr_regs(s, 0x116, "\x00\xe3", 2);
+	ret = rtl2832_sdr_wr_regs(s, 0x118, "\x8e", 1);
+
+	return ret;
+};
+
+static int rtl2832_sdr_set_tuner(struct rtl2832_sdr_state *s)
+{
+	struct dvb_frontend *fe = s->fe;
+	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+
+	unsigned int f_rf = s->ctrl_tuner_rf->val64;
+
+	/*
+	 * bandwidth (Hz)
+	 */
+	unsigned int bandwidth = s->ctrl_tuner_bw->val;
+
+	/*
+	 * intermediate frequency (Hz)
+	 */
+	unsigned int f_if = s->ctrl_tuner_if->val;
+
+	/*
+	 * gain (dB)
+	 */
+	int gain = s->ctrl_tuner_gain->val;
+
+	dev_dbg(&s->udev->dev,
+			"%s: f_rf=%u bandwidth=%d f_if=%u gain=%d\n",
+			__func__, f_rf, bandwidth, f_if, gain);
+
+	if (!test_bit(POWER_ON, &s->flags))
+		return 0;
+
+	if (fe->ops.tuner_ops.init)
+		fe->ops.tuner_ops.init(fe);
+
+	c->bandwidth_hz = bandwidth;
+	c->frequency = f_rf;
+
+	if (fe->ops.tuner_ops.set_params)
+		fe->ops.tuner_ops.set_params(fe);
+
+	return 0;
+};
+
+static void rtl2832_sdr_unset_tuner(struct rtl2832_sdr_state *s)
+{
+	struct dvb_frontend *fe = s->fe;
+
+	dev_dbg(&s->udev->dev, "%s:\n", __func__);
+
+	if (fe->ops.tuner_ops.sleep)
+		fe->ops.tuner_ops.sleep(fe);
+
+	return;
+};
+
+static int rtl2832_sdr_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct rtl2832_sdr_state *s = vb2_get_drv_priv(vq);
+	int ret;
+	dev_dbg(&s->udev->dev, "%s:\n", __func__);
+
+	if (!s->udev)
+		return -ENODEV;
+
+	if (mutex_lock_interruptible(&s->v4l2_lock))
+		return -ERESTARTSYS;
+
+	if (s->d->props->power_ctrl)
+		s->d->props->power_ctrl(s->d, 1);
+
+	set_bit(POWER_ON, &s->flags);
+
+	ret = rtl2832_sdr_set_tuner(s);
+	if (ret)
+		goto err;
+
+	ret = rtl2832_sdr_set_adc(s);
+	if (ret)
+		goto err;
+
+	ret = rtl2832_sdr_alloc_stream_bufs(s);
+	if (ret)
+		goto err;
+
+	ret = rtl2832_sdr_alloc_urbs(s);
+	if (ret)
+		goto err;
+
+	ret = rtl2832_sdr_submit_urbs(s);
+	if (ret)
+		goto err;
+
+err:
+	mutex_unlock(&s->v4l2_lock);
+
+	return ret;
+}
+
+static int rtl2832_sdr_stop_streaming(struct vb2_queue *vq)
+{
+	struct rtl2832_sdr_state *s = vb2_get_drv_priv(vq);
+	dev_dbg(&s->udev->dev, "%s:\n", __func__);
+
+	if (mutex_lock_interruptible(&s->v4l2_lock))
+		return -ERESTARTSYS;
+
+	rtl2832_sdr_kill_urbs(s);
+	rtl2832_sdr_free_urbs(s);
+	rtl2832_sdr_free_stream_bufs(s);
+	rtl2832_sdr_cleanup_queued_bufs(s);
+	rtl2832_sdr_unset_tuner(s);
+
+	clear_bit(POWER_ON, &s->flags);
+
+	if (s->d->props->power_ctrl)
+		s->d->props->power_ctrl(s->d, 0);
+
+	mutex_unlock(&s->v4l2_lock);
+
+	return 0;
+}
+
+static struct vb2_ops rtl2832_sdr_vb2_ops = {
+	.queue_setup            = rtl2832_sdr_queue_setup,
+	.buf_prepare            = rtl2832_sdr_buf_prepare,
+	.buf_queue              = rtl2832_sdr_buf_queue,
+	.start_streaming        = rtl2832_sdr_start_streaming,
+	.stop_streaming         = rtl2832_sdr_stop_streaming,
+	.wait_prepare           = vb2_ops_wait_prepare,
+	.wait_finish            = vb2_ops_wait_finish,
+};
+
+static int rtl2832_sdr_enum_input(struct file *file, void *fh, struct v4l2_input *i)
+{
+	if (i->index != 0)
+		return -EINVAL;
+
+	strlcpy(i->name, "SDR data", sizeof(i->name));
+	i->type = V4L2_INPUT_TYPE_CAMERA;
+
+	return 0;
+}
+
+static int rtl2832_sdr_g_input(struct file *file, void *fh, unsigned int *i)
+{
+	*i = 0;
+
+	return 0;
+}
+
+static int rtl2832_sdr_s_input(struct file *file, void *fh, unsigned int i)
+{
+	return i ? -EINVAL : 0;
+}
+
+static int vidioc_s_tuner(struct file *file, void *priv,
+		const struct v4l2_tuner *v)
+{
+	struct rtl2832_sdr_state *s = video_drvdata(file);
+	dev_dbg(&s->udev->dev, "%s:\n", __func__);
+
+	return 0;
+}
+
+static int vidioc_g_tuner(struct file *file, void *priv, struct v4l2_tuner *v)
+{
+	struct rtl2832_sdr_state *s = video_drvdata(file);
+	dev_dbg(&s->udev->dev, "%s:\n", __func__);
+
+	strcpy(v->name, "SDR RX");
+	v->capability = V4L2_TUNER_CAP_LOW;
+
+	return 0;
+}
+
+static int vidioc_s_frequency(struct file *file, void *priv,
+		const struct v4l2_frequency *f)
+{
+	struct rtl2832_sdr_state *s = video_drvdata(file);
+	dev_dbg(&s->udev->dev, "%s: frequency=%lu Hz (%u)\n",
+			__func__, f->frequency * 625UL / 10UL, f->frequency);
+
+	return v4l2_ctrl_s_ctrl_int64(s->ctrl_tuner_rf,
+			f->frequency * 625UL / 10UL);
+}
+
+static const struct v4l2_ioctl_ops rtl2832_sdr_ioctl_ops = {
+	.vidioc_querycap          = rtl2832_sdr_querycap,
+
+	.vidioc_enum_input        = rtl2832_sdr_enum_input,
+	.vidioc_g_input           = rtl2832_sdr_g_input,
+	.vidioc_s_input           = rtl2832_sdr_s_input,
+
+	.vidioc_reqbufs           = vb2_ioctl_reqbufs,
+	.vidioc_create_bufs       = vb2_ioctl_create_bufs,
+	.vidioc_prepare_buf       = vb2_ioctl_prepare_buf,
+	.vidioc_querybuf          = vb2_ioctl_querybuf,
+	.vidioc_qbuf              = vb2_ioctl_qbuf,
+	.vidioc_dqbuf             = vb2_ioctl_dqbuf,
+
+	.vidioc_streamon          = vb2_ioctl_streamon,
+	.vidioc_streamoff         = vb2_ioctl_streamoff,
+
+	.vidioc_g_tuner           = vidioc_g_tuner,
+	.vidioc_s_tuner           = vidioc_s_tuner,
+	.vidioc_s_frequency       = vidioc_s_frequency,
+
+	.vidioc_subscribe_event   = v4l2_ctrl_subscribe_event,
+	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
+	.vidioc_log_status        = v4l2_ctrl_log_status,
+};
+
+static const struct v4l2_file_operations rtl2832_sdr_fops = {
+	.owner                    = THIS_MODULE,
+	.open                     = v4l2_fh_open,
+	.release                  = vb2_fop_release,
+	.read                     = vb2_fop_read,
+	.poll                     = vb2_fop_poll,
+	.mmap                     = vb2_fop_mmap,
+	.unlocked_ioctl           = video_ioctl2,
+};
+
+static struct video_device rtl2832_sdr_template = {
+	.name                     = "Realtek RTL2832U SDR",
+	.release                  = video_device_release_empty,
+	.fops                     = &rtl2832_sdr_fops,
+	.ioctl_ops                = &rtl2832_sdr_ioctl_ops,
+};
+
+static int rtl2832_sdr_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct rtl2832_sdr_state *s =
+			container_of(ctrl->handler, struct rtl2832_sdr_state,
+					ctrl_handler);
+	int ret;
+	dev_dbg(&s->udev->dev,
+			"%s: id=%d name=%s val=%d min=%d max=%d step=%d\n",
+			__func__, ctrl->id, ctrl->name, ctrl->val,
+			ctrl->minimum, ctrl->maximum, ctrl->step);
+
+	switch (ctrl->id) {
+	case RTL2832_SDR_CID_SAMPLING_MODE:
+	case RTL2832_SDR_CID_SAMPLING_RATE:
+	case RTL2832_SDR_CID_SAMPLING_RESOLUTION:
+		ret = rtl2832_sdr_set_adc(s);
+		break;
+	case RTL2832_SDR_CID_TUNER_RF:
+	case RTL2832_SDR_CID_TUNER_BW:
+	case RTL2832_SDR_CID_TUNER_IF:
+	case RTL2832_SDR_CID_TUNER_GAIN:
+		ret = rtl2832_sdr_set_tuner(s);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static const struct v4l2_ctrl_ops rtl2832_sdr_ctrl_ops = {
+	.s_ctrl = rtl2832_sdr_s_ctrl,
+};
+
+static void rtl2832_sdr_video_release(struct v4l2_device *v)
+{
+	struct rtl2832_sdr_state *s =
+			container_of(v, struct rtl2832_sdr_state, v4l2_dev);
+
+	v4l2_ctrl_handler_free(&s->ctrl_handler);
+	v4l2_device_unregister(&s->v4l2_dev);
+	kfree(s);
+}
+
+struct dvb_frontend *rtl2832_sdr_attach(struct dvb_frontend *fe,
+		struct i2c_adapter *i2c, const struct rtl2832_sdr_config *cfg)
+{
+	int ret;
+	struct rtl2832_sdr_state *s;
+	struct dvb_usb_device *d = i2c_get_adapdata(i2c);
+	static const char * const ctrl_sampling_mode_qmenu_strings[] = {
+		"Quadrature Sampling",
+		NULL,
+	};
+	static const struct v4l2_ctrl_config ctrl_sampling_mode = {
+		.ops	= &rtl2832_sdr_ctrl_ops,
+		.id	= RTL2832_SDR_CID_SAMPLING_MODE,
+		.type   = V4L2_CTRL_TYPE_MENU,
+		.flags  = V4L2_CTRL_FLAG_INACTIVE,
+		.name	= "Sampling Mode",
+		.qmenu  = ctrl_sampling_mode_qmenu_strings,
+	};
+	static const struct v4l2_ctrl_config ctrl_sampling_rate = {
+		.ops	= &rtl2832_sdr_ctrl_ops,
+		.id	= RTL2832_SDR_CID_SAMPLING_RATE,
+		.type	= V4L2_CTRL_TYPE_INTEGER64,
+		.name	= "Sampling Rate",
+		.min	=  500000,
+		.max	= 4000000,
+		.def    = 2048000,
+		.step	= 1,
+	};
+	static const struct v4l2_ctrl_config ctrl_sampling_resolution = {
+		.ops	= &rtl2832_sdr_ctrl_ops,
+		.id	= RTL2832_SDR_CID_SAMPLING_RESOLUTION,
+		.type	= V4L2_CTRL_TYPE_INTEGER,
+		.flags  = V4L2_CTRL_FLAG_INACTIVE,
+		.name	= "Sampling Resolution",
+		.min	= 8,
+		.max	= 8,
+		.def    = 8,
+		.step	= 1,
+	};
+	static const struct v4l2_ctrl_config ctrl_tuner_rf = {
+		.ops	= &rtl2832_sdr_ctrl_ops,
+		.id	= RTL2832_SDR_CID_TUNER_RF,
+		.type   = V4L2_CTRL_TYPE_INTEGER64,
+		.name	= "Tuner RF",
+		.min	=   40000000,
+		.max	= 2000000000,
+		.def    =  100000000,
+		.step	= 1,
+	};
+	static const struct v4l2_ctrl_config ctrl_tuner_bw = {
+		.ops	= &rtl2832_sdr_ctrl_ops,
+		.id	= RTL2832_SDR_CID_TUNER_BW,
+		.type	= V4L2_CTRL_TYPE_INTEGER,
+		.name	= "Tuner BW",
+		.min	=  200000,
+		.max	= 8000000,
+		.def    =  600000,
+		.step	= 1,
+	};
+	static const struct v4l2_ctrl_config ctrl_tuner_if = {
+		.ops	= &rtl2832_sdr_ctrl_ops,
+		.id	= RTL2832_SDR_CID_TUNER_IF,
+		.type	= V4L2_CTRL_TYPE_INTEGER,
+		.flags  = V4L2_CTRL_FLAG_INACTIVE,
+		.name	= "Tuner IF",
+		.min	= 0,
+		.max	= 10,
+		.def    = 0,
+		.step	= 1,
+	};
+	static const struct v4l2_ctrl_config ctrl_tuner_gain = {
+		.ops	= &rtl2832_sdr_ctrl_ops,
+		.id	= RTL2832_SDR_CID_TUNER_GAIN,
+		.type	= V4L2_CTRL_TYPE_INTEGER,
+		.name	= "Tuner Gain",
+		.min	= 0,
+		.max	= 102,
+		.def    = 0,
+		.step	= 1,
+	};
+
+	s = kzalloc(sizeof(struct rtl2832_sdr_state), GFP_KERNEL);
+	if (s == NULL) {
+		dev_err(&d->udev->dev,
+				"Could not allocate memory for rtl2832_sdr_state\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/* setup the state */
+	s->fe = fe;
+	s->d = d;
+	s->udev = d->udev;
+	s->i2c = i2c;
+	s->cfg = cfg;
+
+	mutex_init(&s->v4l2_lock);
+	mutex_init(&s->vb_queue_lock);
+	spin_lock_init(&s->queued_bufs_lock);
+	INIT_LIST_HEAD(&s->queued_bufs);
+
+	/* Init videobuf2 queue structure */
+	s->vb_queue.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	s->vb_queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_READ;
+	s->vb_queue.drv_priv = s;
+	s->vb_queue.buf_struct_size = sizeof(struct rtl2832_sdr_frame_buf);
+	s->vb_queue.ops = &rtl2832_sdr_vb2_ops;
+	s->vb_queue.mem_ops = &vb2_vmalloc_memops;
+	s->vb_queue.timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+	ret = vb2_queue_init(&s->vb_queue);
+	if (ret < 0) {
+		dev_err(&s->udev->dev, "Could not initialize vb2 queue\n");
+		goto err_free_mem;
+	}
+
+	/* Init video_device structure */
+	s->vdev = rtl2832_sdr_template;
+	s->vdev.queue = &s->vb_queue;
+	s->vdev.queue->lock = &s->vb_queue_lock;
+	set_bit(V4L2_FL_USE_FH_PRIO, &s->vdev.flags);
+	video_set_drvdata(&s->vdev, s);
+
+	/* Register controls */
+	v4l2_ctrl_handler_init(&s->ctrl_handler, 7);
+	v4l2_ctrl_new_custom(&s->ctrl_handler, &ctrl_sampling_mode, NULL);
+	s->ctrl_sampling_rate = v4l2_ctrl_new_custom(&s->ctrl_handler, &ctrl_sampling_rate, NULL);
+	v4l2_ctrl_new_custom(&s->ctrl_handler, &ctrl_sampling_resolution, NULL);
+	s->ctrl_tuner_rf = v4l2_ctrl_new_custom(&s->ctrl_handler, &ctrl_tuner_rf, NULL);
+	s->ctrl_tuner_bw = v4l2_ctrl_new_custom(&s->ctrl_handler, &ctrl_tuner_bw, NULL);
+	s->ctrl_tuner_if = v4l2_ctrl_new_custom(&s->ctrl_handler, &ctrl_tuner_if, NULL);
+	s->ctrl_tuner_gain = v4l2_ctrl_new_custom(&s->ctrl_handler, &ctrl_tuner_gain, NULL);
+	if (s->ctrl_handler.error) {
+		ret = s->ctrl_handler.error;
+		dev_err(&s->udev->dev, "Could not initialize controls\n");
+		goto err_free_controls;
+	}
+
+	/* Register the v4l2_device structure */
+	s->v4l2_dev.release = rtl2832_sdr_video_release;
+	ret = v4l2_device_register(&s->udev->dev, &s->v4l2_dev);
+	if (ret) {
+		dev_err(&s->udev->dev,
+				"Failed to register v4l2-device (%d)\n", ret);
+		goto err_free_controls;
+	}
+
+	s->v4l2_dev.ctrl_handler = &s->ctrl_handler;
+	s->vdev.v4l2_dev = &s->v4l2_dev;
+	s->vdev.lock = &s->v4l2_lock;
+
+	ret = video_register_device(&s->vdev, VFL_TYPE_GRABBER, -1);
+	if (ret < 0) {
+		dev_err(&s->udev->dev,
+				"Failed to register as video device (%d)\n",
+				ret);
+		goto err_unregister_v4l2_dev;
+	}
+	dev_info(&s->udev->dev, "Registered as %s\n",
+			video_device_node_name(&s->vdev));
+
+	fe->sec_priv = s;
+	fe->ops.release_sec = rtl2832_sdr_release_sec;
+
+	dev_info(&s->i2c->dev, "%s: Realtek RTL2832 SDR attached\n",
+			KBUILD_MODNAME);
+	return fe;
+
+err_unregister_v4l2_dev:
+	v4l2_device_unregister(&s->v4l2_dev);
+err_free_controls:
+	v4l2_ctrl_handler_free(&s->ctrl_handler);
+err_free_mem:
+	kfree(s);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(rtl2832_sdr_attach);
+
+MODULE_AUTHOR("Antti Palosaari <crope@iki.fi>");
+MODULE_DESCRIPTION("Realtek RTL2832 SDR driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.h b/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.h
new file mode 100644
index 0000000..69d97c1
--- /dev/null
+++ b/drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.h
@@ -0,0 +1,52 @@ 
+/*
+ * Realtek RTL2832U SDR driver
+ *
+ * Copyright (C) 2013 Antti Palosaari <crope@iki.fi>
+ *
+ *    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.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License along
+ *    with this program; if not, write to the Free Software Foundation, Inc.,
+ *    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * GNU Radio plugin "gr-kernel" for device usage will be on:
+ * http://git.linuxtv.org/anttip/gr-kernel.git
+ *
+ * TODO:
+ * Help is very highly welcome for these + all the others you could imagine:
+ * - move controls to V4L2 API
+ * - use libv4l2 for stream format conversions
+ * - gr-kernel: switch to v4l2_mmap (current read eats a lot of cpu)
+ * - SDRSharp support
+ */
+
+#ifndef RTL2832_SDR_H
+#define RTL2832_SDR_H
+
+#include <linux/kconfig.h>
+
+struct rtl2832_sdr_config {
+	u8 i2c_addr;
+};
+
+#if IS_ENABLED(CONFIG_DVB_RTL2832_SDR)
+extern struct dvb_frontend *rtl2832_sdr_attach(struct dvb_frontend *fe,
+	struct i2c_adapter *i2c, const struct rtl2832_sdr_config *cfg);
+#else
+static inline struct dvb_frontend *rtl2832_sdr_attach(struct dvb_frontend *fe,
+	struct i2c_adapter *i2c, const struct rtl2832_sdr_config *cfg)
+{
+	dev_warn(&i2c->dev, "%s: driver disabled by Kconfig\n", __func__);
+	return NULL;
+}
+#endif
+
+#endif /* RTL2832_SDR_H */