/*
 * Mirics MSi3101 SDR Dongle 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.
 *
 * That driver is somehow based of pwc driver:
 *  (C) 1999-2004 Nemosoft Unv.
 *  (C) 2004-2006 Luc Saillard (luc@saillard.org)
 *  (C) 2011 Hans de Goede <hdegoede@redhat.com>
 *
 * Development tree of that driver will be on:
 * http://git.linuxtv.org/anttip/media_tree.git/shortlog/refs/heads/mirics
 *
 * 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:
 * - split USB ADC interface and RF tuner to own drivers (msi2500 and msi001)
 * - 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 <linux/module.h>
#include <linux/slab.h>
#include <linux/gcd.h>
#include <asm/div64.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include <linux/usb.h>
#include <media/videobuf2-vmalloc.h>

struct msi3101_gain {
	u8 tot:7;
	u8 baseband:6;
	bool lna:1;
	bool mixer:1;
};

/* 60 – 120 MHz band, lna 24dB, mixer 19dB */
static const struct msi3101_gain msi3101_gain_lut_120[] = {
	{  0,  0,  0,  0},
	{  1,  1,  0,  0},
	{  2,  2,  0,  0},
	{  3,  3,  0,  0},
	{  4,  4,  0,  0},
	{  5,  5,  0,  0},
	{  6,  6,  0,  0},
	{  7,  7,  0,  0},
	{  8,  8,  0,  0},
	{  9,  9,  0,  0},
	{ 10, 10,  0,  0},
	{ 11, 11,  0,  0},
	{ 12, 12,  0,  0},
	{ 13, 13,  0,  0},
	{ 14, 14,  0,  0},
	{ 15, 15,  0,  0},
	{ 16, 16,  0,  0},
	{ 17, 17,  0,  0},
	{ 18, 18,  0,  0},
	{ 19, 19,  0,  0},
	{ 20, 20,  0,  0},
	{ 21, 21,  0,  0},
	{ 22, 22,  0,  0},
	{ 23, 23,  0,  0},
	{ 24, 24,  0,  0},
	{ 25, 25,  0,  0},
	{ 26, 26,  0,  0},
	{ 27, 27,  0,  0},
	{ 28, 28,  0,  0},
	{ 29,  5,  1,  0},
	{ 30,  6,  1,  0},
	{ 31,  7,  1,  0},
	{ 32,  8,  1,  0},
	{ 33,  9,  1,  0},
	{ 34, 10,  1,  0},
	{ 35, 11,  1,  0},
	{ 36, 12,  1,  0},
	{ 37, 13,  1,  0},
	{ 38, 14,  1,  0},
	{ 39, 15,  1,  0},
	{ 40, 16,  1,  0},
	{ 41, 17,  1,  0},
	{ 42, 18,  1,  0},
	{ 43, 19,  1,  0},
	{ 44, 20,  1,  0},
	{ 45, 21,  1,  0},
	{ 46, 22,  1,  0},
	{ 47, 23,  1,  0},
	{ 48, 24,  1,  0},
	{ 49, 25,  1,  0},
	{ 50, 26,  1,  0},
	{ 51, 27,  1,  0},
	{ 52, 28,  1,  0},
	{ 53, 29,  1,  0},
	{ 54, 30,  1,  0},
	{ 55, 31,  1,  0},
	{ 56, 32,  1,  0},
	{ 57, 33,  1,  0},
	{ 58, 34,  1,  0},
	{ 59, 35,  1,  0},
	{ 60, 36,  1,  0},
	{ 61, 37,  1,  0},
	{ 62, 38,  1,  0},
	{ 63, 39,  1,  0},
	{ 64, 40,  1,  0},
	{ 65, 41,  1,  0},
	{ 66, 42,  1,  0},
	{ 67, 43,  1,  0},
	{ 68, 44,  1,  0},
	{ 69, 45,  1,  0},
	{ 70, 46,  1,  0},
	{ 71, 47,  1,  0},
	{ 72, 48,  1,  0},
	{ 73, 49,  1,  0},
	{ 74, 50,  1,  0},
	{ 75, 51,  1,  0},
	{ 76, 52,  1,  0},
	{ 77, 53,  1,  0},
	{ 78, 54,  1,  0},
	{ 79, 55,  1,  0},
	{ 80, 56,  1,  0},
	{ 81, 57,  1,  0},
	{ 82, 58,  1,  0},
	{ 83, 40,  1,  1},
	{ 84, 41,  1,  1},
	{ 85, 42,  1,  1},
	{ 86, 43,  1,  1},
	{ 87, 44,  1,  1},
	{ 88, 45,  1,  1},
	{ 89, 46,  1,  1},
	{ 90, 47,  1,  1},
	{ 91, 48,  1,  1},
	{ 92, 49,  1,  1},
	{ 93, 50,  1,  1},
	{ 94, 51,  1,  1},
	{ 95, 52,  1,  1},
	{ 96, 53,  1,  1},
	{ 97, 54,  1,  1},
	{ 98, 55,  1,  1},
	{ 99, 56,  1,  1},
	{100, 57,  1,  1},
	{101, 58,  1,  1},
	{102, 59,  1,  1},
};

/* 120 – 245 MHz band, lna 24dB, mixer 19dB */
static const struct msi3101_gain msi3101_gain_lut_245[] = {
	{  0,  0,  0,  0},
	{  1,  1,  0,  0},
	{  2,  2,  0,  0},
	{  3,  3,  0,  0},
	{  4,  4,  0,  0},
	{  5,  5,  0,  0},
	{  6,  6,  0,  0},
	{  7,  7,  0,  0},
	{  8,  8,  0,  0},
	{  9,  9,  0,  0},
	{ 10, 10,  0,  0},
	{ 11, 11,  0,  0},
	{ 12, 12,  0,  0},
	{ 13, 13,  0,  0},
	{ 14, 14,  0,  0},
	{ 15, 15,  0,  0},
	{ 16, 16,  0,  0},
	{ 17, 17,  0,  0},
	{ 18, 18,  0,  0},
	{ 19, 19,  0,  0},
	{ 20, 20,  0,  0},
	{ 21, 21,  0,  0},
	{ 22, 22,  0,  0},
	{ 23, 23,  0,  0},
	{ 24, 24,  0,  0},
	{ 25, 25,  0,  0},
	{ 26, 26,  0,  0},
	{ 27, 27,  0,  0},
	{ 28, 28,  0,  0},
	{ 29,  5,  1,  0},
	{ 30,  6,  1,  0},
	{ 31,  7,  1,  0},
	{ 32,  8,  1,  0},
	{ 33,  9,  1,  0},
	{ 34, 10,  1,  0},
	{ 35, 11,  1,  0},
	{ 36, 12,  1,  0},
	{ 37, 13,  1,  0},
	{ 38, 14,  1,  0},
	{ 39, 15,  1,  0},
	{ 40, 16,  1,  0},
	{ 41, 17,  1,  0},
	{ 42, 18,  1,  0},
	{ 43, 19,  1,  0},
	{ 44, 20,  1,  0},
	{ 45, 21,  1,  0},
	{ 46, 22,  1,  0},
	{ 47, 23,  1,  0},
	{ 48, 24,  1,  0},
	{ 49, 25,  1,  0},
	{ 50, 26,  1,  0},
	{ 51, 27,  1,  0},
	{ 52, 28,  1,  0},
	{ 53, 29,  1,  0},
	{ 54, 30,  1,  0},
	{ 55, 31,  1,  0},
	{ 56, 32,  1,  0},
	{ 57, 33,  1,  0},
	{ 58, 34,  1,  0},
	{ 59, 35,  1,  0},
	{ 60, 36,  1,  0},
	{ 61, 37,  1,  0},
	{ 62, 38,  1,  0},
	{ 63, 39,  1,  0},
	{ 64, 40,  1,  0},
	{ 65, 41,  1,  0},
	{ 66, 42,  1,  0},
	{ 67, 43,  1,  0},
	{ 68, 44,  1,  0},
	{ 69, 45,  1,  0},
	{ 70, 46,  1,  0},
	{ 71, 47,  1,  0},
	{ 72, 48,  1,  0},
	{ 73, 49,  1,  0},
	{ 74, 50,  1,  0},
	{ 75, 51,  1,  0},
	{ 76, 52,  1,  0},
	{ 77, 53,  1,  0},
	{ 78, 54,  1,  0},
	{ 79, 55,  1,  0},
	{ 80, 56,  1,  0},
	{ 81, 57,  1,  0},
	{ 82, 58,  1,  0},
	{ 83, 40,  1,  1},
	{ 84, 41,  1,  1},
	{ 85, 42,  1,  1},
	{ 86, 43,  1,  1},
	{ 87, 44,  1,  1},
	{ 88, 45,  1,  1},
	{ 89, 46,  1,  1},
	{ 90, 47,  1,  1},
	{ 91, 48,  1,  1},
	{ 92, 49,  1,  1},
	{ 93, 50,  1,  1},
	{ 94, 51,  1,  1},
	{ 95, 52,  1,  1},
	{ 96, 53,  1,  1},
	{ 97, 54,  1,  1},
	{ 98, 55,  1,  1},
	{ 99, 56,  1,  1},
	{100, 57,  1,  1},
	{101, 58,  1,  1},
	{102, 59,  1,  1},
};

/* 420 – 1000 MHz band, lna 7dB, mixer 19dB */
static const struct msi3101_gain msi3101_gain_lut_1000[] = {
	{  0,  0, 0,  0},
	{  1,  1, 0,  0},
	{  2,  2, 0,  0},
	{  3,  3, 0,  0},
	{  4,  4, 0,  0},
	{  5,  5, 0,  0},
	{  6,  6, 0,  0},
	{  7,  7, 0,  0},
	{  8,  8, 0,  0},
	{  9,  9, 0,  0},
	{ 10, 10, 0,  0},
	{ 11, 11, 0,  0},
	{ 12,  5, 1,  0},
	{ 13,  6, 1,  0},
	{ 14,  7, 1,  0},
	{ 15,  8, 1,  0},
	{ 16,  9, 1,  0},
	{ 17, 10, 1,  0},
	{ 18, 11, 1,  0},
	{ 19, 12, 1,  0},
	{ 20, 13, 1,  0},
	{ 21, 14, 1,  0},
	{ 22, 15, 1,  0},
	{ 23, 16, 1,  0},
	{ 24, 17, 1,  0},
	{ 25, 18, 1,  0},
	{ 26, 19, 1,  0},
	{ 27, 20, 1,  0},
	{ 28, 21, 1,  0},
	{ 29, 22, 1,  0},
	{ 30, 23, 1,  0},
	{ 31, 24, 1,  0},
	{ 32, 25, 1,  0},
	{ 33, 26, 1,  0},
	{ 34, 27, 1,  0},
	{ 35, 28, 1,  0},
	{ 36, 29, 1,  0},
	{ 37, 30, 1,  0},
	{ 38, 31, 1,  0},
	{ 39, 32, 1,  0},
	{ 40, 33, 1,  0},
	{ 41, 34, 1,  0},
	{ 42, 35, 1,  0},
	{ 43, 36, 1,  0},
	{ 44, 37, 1,  0},
	{ 45, 38, 1,  0},
	{ 46, 39, 1,  0},
	{ 47, 40, 1,  0},
	{ 48, 41, 1,  0},
	{ 49, 42, 1,  0},
	{ 50, 43, 1,  0},
	{ 51, 44, 1,  0},
	{ 52, 45, 1,  0},
	{ 53, 46, 1,  0},
	{ 54, 47, 1,  0},
	{ 55, 48, 1,  0},
	{ 56, 49, 1,  0},
	{ 57, 50, 1,  0},
	{ 58, 51, 1,  0},
	{ 59, 52, 1,  0},
	{ 60, 53, 1,  0},
	{ 61, 54, 1,  0},
	{ 62, 55, 1,  0},
	{ 63, 56, 1,  0},
	{ 64, 57, 1,  0},
	{ 65, 58, 1,  0},
	{ 66, 40, 1,  1},
	{ 67, 41, 1,  1},
	{ 68, 42, 1,  1},
	{ 69, 43, 1,  1},
	{ 70, 44, 1,  1},
	{ 71, 45, 1,  1},
	{ 72, 46, 1,  1},
	{ 73, 47, 1,  1},
	{ 74, 48, 1,  1},
	{ 75, 49, 1,  1},
	{ 76, 50, 1,  1},
	{ 77, 51, 1,  1},
	{ 78, 52, 1,  1},
	{ 79, 53, 1,  1},
	{ 80, 54, 1,  1},
	{ 81, 55, 1,  1},
	{ 82, 56, 1,  1},
	{ 83, 57, 1,  1},
	{ 84, 58, 1,  1},
	{ 85, 59, 1,  1},
};

/*
 *   iConfiguration          0
 *     bInterfaceNumber        0
 *     bAlternateSetting       1
 *     bNumEndpoints           1
 *       bEndpointAddress     0x81  EP 1 IN
 *       bmAttributes            1
 *         Transfer Type            Isochronous
 *       wMaxPacketSize     0x1400  3x 1024 bytes
 *       bInterval               1
 */
#define MAX_ISO_BUFS            (8)
#define ISO_FRAMES_PER_DESC     (8)
#define ISO_MAX_FRAME_SIZE      (3 * 1024)
#define ISO_BUFFER_SIZE         (ISO_FRAMES_PER_DESC * ISO_MAX_FRAME_SIZE)
#define MAX_ISOC_ERRORS         20

/* TODO: These should be moved to V4L2 API */
#define MSI3101_CID_SAMPLING_MODE         ((V4L2_CID_USER_BASE | 0xf000) + 0)
#define MSI3101_CID_SAMPLING_RATE         ((V4L2_CID_USER_BASE | 0xf000) + 1)
#define MSI3101_CID_SAMPLING_RESOLUTION   ((V4L2_CID_USER_BASE | 0xf000) + 2)
#define MSI3101_CID_TUNER_RF              ((V4L2_CID_USER_BASE | 0xf000) + 10)
#define MSI3101_CID_TUNER_BW              ((V4L2_CID_USER_BASE | 0xf000) + 11)
#define MSI3101_CID_TUNER_IF              ((V4L2_CID_USER_BASE | 0xf000) + 12)
#define MSI3101_CID_TUNER_GAIN            ((V4L2_CID_USER_BASE | 0xf000) + 13)

/* intermediate buffers with raw data from the USB device */
struct msi3101_frame_buf {
	struct vb2_buffer vb;   /* common v4l buffer stuff -- must be first */
	struct list_head list;
};

struct msi3101_state {
	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 isoc_errors; /* number of contiguous ISOC errors */
	unsigned int vb_full; /* vb is full and packets dropped */

	struct urb *urbs[MAX_ISO_BUFS];
	int (*convert_stream) (struct msi3101_state *s, u32 *dst, u8 *src,
			unsigned int src_len);

	/* 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;

	u32 next_sample; /* for track lost packets */
	u32 sample; /* for sample rate calc */
	unsigned long jiffies;
	unsigned int sample_ctrl_bit[4];
};

/* Private functions */
static struct msi3101_frame_buf *msi3101_get_next_fill_buf(
		struct msi3101_state *s)
{
	unsigned long flags = 0;
	struct msi3101_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 msi3101_frame_buf, list);
	list_del(&buf->list);
leave:
	spin_unlock_irqrestore(&s->queued_bufs_lock, flags);
	return buf;
}

/*
 * +===========================================================================
 * |   00-1023 | USB packet type '384'
 * +===========================================================================
 * |   00-  03 | sequence number of first sample in that USB packet
 * +---------------------------------------------------------------------------
 * |   04-  15 | garbage
 * +---------------------------------------------------------------------------
 * |   16- 175 | samples
 * +---------------------------------------------------------------------------
 * |  176- 179 | control bits for previous samples
 * +---------------------------------------------------------------------------
 * |  180- 339 | samples
 * +---------------------------------------------------------------------------
 * |  340- 343 | control bits for previous samples
 * +---------------------------------------------------------------------------
 * |  344- 503 | samples
 * +---------------------------------------------------------------------------
 * |  504- 507 | control bits for previous samples
 * +---------------------------------------------------------------------------
 * |  508- 667 | samples
 * +---------------------------------------------------------------------------
 * |  668- 671 | control bits for previous samples
 * +---------------------------------------------------------------------------
 * |  672- 831 | samples
 * +---------------------------------------------------------------------------
 * |  832- 835 | control bits for previous samples
 * +---------------------------------------------------------------------------
 * |  836- 995 | samples
 * +---------------------------------------------------------------------------
 * |  996- 999 | control bits for previous samples
 * +---------------------------------------------------------------------------
 * | 1000-1023 | garbage
 * +---------------------------------------------------------------------------
 *
 * Bytes 4 - 7 could have some meaning?
 *
 * Control bits for previous samples is 32-bit field, containing 16 x 2-bit
 * numbers. This results one 2-bit number for 8 samples. It is likely used for
 * for bit shifting sample by given bits, increasing actual sampling resolution.
 * Number 2 (0b10) was never seen.
 *
 * 6 * 16 * 2 * 4 = 768 samples. 768 * 4 = 3072 bytes
 */

/*
 * 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 msi3101_convert_sample_504(struct msi3101_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 int msi3101_convert_stream_504(struct msi3101_state *s, u32 *dst,
		u8 *src, unsigned int src_len)
{
	int i, j, i_max, dst_len = 0;
	u16 sample[2];
	u32 sample_num[3];

	/* There could be 1-3 1024 bytes URB frames */
	i_max = src_len / 1024;

	for (i = 0; i < i_max; i++) {
		sample_num[i] = src[3] << 24 | src[2] << 16 | src[1] << 8 | src[0] << 0;
		if (i == 0 && s->next_sample != sample_num[0]) {
			dev_dbg_ratelimited(&s->udev->dev,
					"%d samples lost, %d %08x:%08x\n",
					sample_num[0] - s->next_sample,
					src_len, s->next_sample, sample_num[0]);
		}

		/*
		 * Dump all unknown 'garbage' data - maybe we will discover
		 * someday if there is something rational...
		 */
		dev_dbg_ratelimited(&s->udev->dev, "%*ph\n", 12, &src[4]);

		src += 16;
		for (j = 0; j < 1008; j += 2) {
			sample[0] = src[j + 0];
			sample[1] = src[j + 1];

			*dst++ = msi3101_convert_sample_504(s, sample[0]);
			*dst++ = msi3101_convert_sample_504(s, sample[1]);
		}
		/* 504 x I+Q 32bit float samples */
		dst_len += 504 * 2 * 4;
		src += 1008;
	}

	/* 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 = sample_num[i_max - 1] - s->sample;
		s->jiffies = jiffies_now;
		s->sample = sample_num[i_max - 1];
		dev_dbg(&s->udev->dev,
				"slen=%d samples=%u msecs=%lu sampling rate=%lu\n",
				src_len, samples, msecs,
				samples * 1000UL / msecs);
	}

	/* next sample (sample = sample + i * 504) */
	s->next_sample = sample_num[i_max - 1] + 504;

	return dst_len;
}

/*
 * Converts signed ~10+2-bit integer into 32-bit IEEE floating point
 * representation.
 */
static u32 msi3101_convert_sample_384(struct msi3101_state *s, u16 x, int shift)
{
	u32 msb, exponent, fraction, sign;
	s->sample_ctrl_bit[shift]++;

	/* Zero is special */
	if (!x)
		return 0;

	if (shift == 3)
		shift =	2;

	/* Convert 10-bit two's complement to 12-bit */
	if (x & (1 << 9)) {
		x |= ~0U << 10; /* set all the rest bits to one */
		x <<= shift;
		x = -x;
		x &= 0x7ff; /* result is 11 bit ... + sign */
		sign = 1 << 31;
	} else {
		x <<= shift;
		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 int msi3101_convert_stream_384(struct msi3101_state *s, u32 *dst,
		u8 *src, unsigned int src_len)
{
	int i, j, k, l, i_max, dst_len = 0;
	u16 sample[4];
	u32 bits;
	u32 sample_num[3];

	/* There could be 1-3 1024 bytes URB frames */
	i_max = src_len / 1024;
	for (i = 0; i < i_max; i++) {
		sample_num[i] = src[3] << 24 | src[2] << 16 | src[1] << 8 | src[0] << 0;
		if (i == 0 && s->next_sample != sample_num[0]) {
			dev_dbg_ratelimited(&s->udev->dev,
					"%d samples lost, %d %08x:%08x\n",
					sample_num[0] - s->next_sample,
					src_len, s->next_sample, sample_num[0]);
		}

		/*
		 * Dump all unknown 'garbage' data - maybe we will discover
		 * someday if there is something rational...
		 */
		dev_dbg_ratelimited(&s->udev->dev,
				"%*ph  %*ph\n", 12, &src[4], 24, &src[1000]);

		src += 16;
		for (j = 0; j < 6; j++) {
			bits = src[160 + 3] << 24 | src[160 + 2] << 16 | src[160 + 1] << 8 | src[160 + 0] << 0;
			for (k = 0; k < 16; k++) {
				for (l = 0; l < 10; l += 5) {
					sample[0] = (src[l + 0] & 0xff) >> 0 | (src[l + 1] & 0x03) << 8;
					sample[1] = (src[l + 1] & 0xfc) >> 2 | (src[l + 2] & 0x0f) << 6;
					sample[2] = (src[l + 2] & 0xf0) >> 4 | (src[l + 3] & 0x3f) << 4;
					sample[3] = (src[l + 3] & 0xc0) >> 6 | (src[l + 4] & 0xff) << 2;

					*dst++ = msi3101_convert_sample_384(s, sample[0], (bits >> (2 * k)) & 0x3);
					*dst++ = msi3101_convert_sample_384(s, sample[1], (bits >> (2 * k)) & 0x3);
					*dst++ = msi3101_convert_sample_384(s, sample[2], (bits >> (2 * k)) & 0x3);
					*dst++ = msi3101_convert_sample_384(s, sample[3], (bits >> (2 * k)) & 0x3);
				}
				src += 10;
			}
			dev_dbg_ratelimited(&s->udev->dev,
					"sample control bits %08x\n", bits);
			src += 4;
		}
		/* 384 x I+Q 32bit float samples */
		dst_len += 384 * 2 * 4;
		src += 24;
	}

	/* 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 = sample_num[i_max - 1] - s->sample;
		s->jiffies = jiffies_now;
		s->sample = sample_num[i_max - 1];
		dev_dbg(&s->udev->dev,
				"slen=%d samples=%u msecs=%lu sampling rate=%lu bits=%d.%d.%d.%d\n",
				src_len, samples, msecs,
				samples * 1000UL / msecs,
				s->sample_ctrl_bit[0], s->sample_ctrl_bit[1],
				s->sample_ctrl_bit[2], s->sample_ctrl_bit[3]);
	}

	/* next sample (sample = sample + i * 384) */
	s->next_sample = sample_num[i_max - 1] + 384;

	return dst_len;
}

/*
 * Converts signed 12-bit integer into 32-bit IEEE floating point
 * representation.
 */
static u32 msi3101_convert_sample_336(struct msi3101_state *s, u16 x)
{
	u32 msb, exponent, fraction, sign;

	/* Zero is special */
	if (!x)
		return 0;

	/* Negative / positive value */
	if (x & (1 << 11)) {
		x = -x;
		x &= 0x7ff; /* result is 11 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 int msi3101_convert_stream_336(struct msi3101_state *s, u32 *dst,
		u8 *src, unsigned int src_len)
{
	int i, j, i_max, dst_len = 0;
	u16 sample[2];
	u32 sample_num[3];

	/* There could be 1-3 1024 bytes URB frames */
	i_max = src_len / 1024;

	for (i = 0; i < i_max; i++) {
		sample_num[i] = src[3] << 24 | src[2] << 16 | src[1] << 8 | src[0] << 0;
		if (i == 0 && s->next_sample != sample_num[0]) {
			dev_dbg_ratelimited(&s->udev->dev,
					"%d samples lost, %d %08x:%08x\n",
					sample_num[0] - s->next_sample,
					src_len, s->next_sample, sample_num[0]);
		}

		/*
		 * Dump all unknown 'garbage' data - maybe we will discover
		 * someday if there is something rational...
		 */
		dev_dbg_ratelimited(&s->udev->dev, "%*ph\n", 12, &src[4]);

		src += 16;
		for (j = 0; j < 1008; j += 3) {
			sample[0] = (src[j + 0] & 0xff) >> 0 | (src[j + 1] & 0x0f) << 8;
			sample[1] = (src[j + 1] & 0xf0) >> 4 | (src[j + 2] & 0xff) << 4;

			*dst++ = msi3101_convert_sample_336(s, sample[0]);
			*dst++ = msi3101_convert_sample_336(s, sample[1]);
		}
		/* 336 x I+Q 32bit float samples */
		dst_len += 336 * 2 * 4;
		src += 1008;
	}

	/* 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 = sample_num[i_max - 1] - s->sample;
		s->jiffies = jiffies_now;
		s->sample = sample_num[i_max - 1];
		dev_dbg(&s->udev->dev,
				"slen=%d samples=%u msecs=%lu sampling rate=%lu\n",
				src_len, samples, msecs,
				samples * 1000UL / msecs);
	}

	/* next sample (sample = sample + i * 336) */
	s->next_sample = sample_num[i_max - 1] + 336;

	return dst_len;
}

/*
 * Converts signed 14-bit integer into 32-bit IEEE floating point
 * representation.
 */
static u32 msi3101_convert_sample_252(struct msi3101_state *s, u16 x)
{
	u32 msb, exponent, fraction, sign;

	/* Zero is special */
	if (!x)
		return 0;

	/* Negative / positive value */
	if (x & (1 << 13)) {
		x = -x;
		x &= 0x1fff; /* result is 13 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 int msi3101_convert_stream_252(struct msi3101_state *s, u32 *dst,
		u8 *src, unsigned int src_len)
{
	int i, j, i_max, dst_len = 0;
	u16 sample[2];
	u32 sample_num[3];

	/* There could be 1-3 1024 bytes URB frames */
	i_max = src_len / 1024;

	for (i = 0; i < i_max; i++) {
		sample_num[i] = src[3] << 24 | src[2] << 16 | src[1] << 8 | src[0] << 0;
		if (i == 0 && s->next_sample != sample_num[0]) {
			dev_dbg_ratelimited(&s->udev->dev,
					"%d samples lost, %d %08x:%08x\n",
					sample_num[0] - s->next_sample,
					src_len, s->next_sample, sample_num[0]);
		}

		/*
		 * Dump all unknown 'garbage' data - maybe we will discover
		 * someday if there is something rational...
		 */
		dev_dbg_ratelimited(&s->udev->dev, "%*ph\n", 12, &src[4]);

		src += 16;
		for (j = 0; j < 1008; j += 4) {
			sample[0] = src[j + 0] >> 0 | src[j + 1] << 8;
			sample[1] = src[j + 2] >> 0 | src[j + 3] << 8;

			*dst++ = msi3101_convert_sample_252(s, sample[0]);
			*dst++ = msi3101_convert_sample_252(s, sample[1]);
		}
		/* 252 x I+Q 32bit float samples */
		dst_len += 252 * 2 * 4;
		src += 1008;
	}

	/* 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 = sample_num[i_max - 1] - s->sample;
		s->jiffies = jiffies_now;
		s->sample = sample_num[i_max - 1];
		dev_dbg(&s->udev->dev,
				"slen=%d samples=%u msecs=%lu sampling rate=%lu\n",
				src_len, samples, msecs,
				samples * 1000UL / msecs);
	}

	/* next sample (sample = sample + i * 252) */
	s->next_sample = sample_num[i_max - 1] + 252;

	return dst_len;
}

/*
 * This gets called for the Isochronous pipe (stream). This is done in interrupt
 * time, so it has to be fast, not crash, and not stall. Neat.
 */
static void msi3101_isoc_handler(struct urb *urb)
{
	struct msi3101_state *s = (struct msi3101_state *)urb->context;
	int i, flen, fstatus;
	unsigned char *iso_buf = NULL;
	struct msi3101_frame_buf *fbuf;

	if (urb->status == -ENOENT || urb->status == -ECONNRESET ||
			urb->status == -ESHUTDOWN) {
		dev_dbg(&s->udev->dev, "URB (%p) unlinked %ssynchronuously\n",
				urb, urb->status == -ENOENT ? "" : "a");
		return;
	}

	if (urb->status != 0) {
		dev_dbg(&s->udev->dev,
				"msi3101_isoc_handler() called with status %d\n",
				urb->status);
		/* Give up after a number of contiguous errors */
		if (++s->isoc_errors > MAX_ISOC_ERRORS)
			dev_dbg(&s->udev->dev,
					"Too many ISOC errors, bailing out\n");
		goto handler_end;
	} else {
		/* Reset ISOC error counter. We did get here, after all. */
		s->isoc_errors = 0;
	}

	/* Compact data */
	for (i = 0; i < urb->number_of_packets; i++) {
		void *ptr;

		/* Check frame error */
		fstatus = urb->iso_frame_desc[i].status;
		if (fstatus) {
			dev_dbg_ratelimited(&s->udev->dev,
					"frame=%d/%d has error %d skipping\n",
					i, urb->number_of_packets, fstatus);
			goto skip;
		}

		/* Check if that frame contains data */
		flen = urb->iso_frame_desc[i].actual_length;
		if (flen == 0)
			goto skip;

		iso_buf = urb->transfer_buffer + urb->iso_frame_desc[i].offset;

		/* Get free framebuffer */
		fbuf = msi3101_get_next_fill_buf(s);
		if (fbuf == NULL) {
			s->vb_full++;
			dev_dbg_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);
		flen = s->convert_stream(s, ptr, iso_buf, flen);
		vb2_set_plane_payload(&fbuf->vb, 0, flen);
		vb2_buffer_done(&fbuf->vb, VB2_BUF_STATE_DONE);
skip:
		;
	}

handler_end:
	i = usb_submit_urb(urb, GFP_ATOMIC);
	if (i != 0)
		dev_dbg(&s->udev->dev,
				"Error (%d) re-submitting urb in msi3101_isoc_handler\n",
				i);
}

static void msi3101_iso_stop(struct msi3101_state *s)
{
	int i;
	dev_dbg(&s->udev->dev, "%s:\n", __func__);

	/* Unlinking ISOC buffers one by one */
	for (i = 0; i < MAX_ISO_BUFS; i++) {
		if (s->urbs[i]) {
			dev_dbg(&s->udev->dev, "Unlinking URB %p\n",
					s->urbs[i]);
			usb_kill_urb(s->urbs[i]);
		}
	}
}

static void msi3101_iso_free(struct msi3101_state *s)
{
	int i;
	dev_dbg(&s->udev->dev, "%s:\n", __func__);

	/* Freeing ISOC buffers one by one */
	for (i = 0; i < MAX_ISO_BUFS; i++) {
		if (s->urbs[i]) {
			dev_dbg(&s->udev->dev, "Freeing URB\n");
			if (s->urbs[i]->transfer_buffer) {
				usb_free_coherent(s->udev,
					s->urbs[i]->transfer_buffer_length,
					s->urbs[i]->transfer_buffer,
					s->urbs[i]->transfer_dma);
			}
			usb_free_urb(s->urbs[i]);
			s->urbs[i] = NULL;
		}
	}
}

/* Both v4l2_lock and vb_queue_lock should be locked when calling this */
static void msi3101_isoc_cleanup(struct msi3101_state *s)
{
	dev_dbg(&s->udev->dev, "%s:\n", __func__);

	msi3101_iso_stop(s);
	msi3101_iso_free(s);
}

/* Both v4l2_lock and vb_queue_lock should be locked when calling this */
static int msi3101_isoc_init(struct msi3101_state *s)
{
	struct usb_device *udev;
	struct urb *urb;
	int i, j, ret;
	dev_dbg(&s->udev->dev, "%s:\n", __func__);

	s->isoc_errors = 0;
	udev = s->udev;

	ret = usb_set_interface(s->udev, 0, 1);
	if (ret < 0)
		return ret;

	/* Allocate and init Isochronuous urbs */
	for (i = 0; i < MAX_ISO_BUFS; i++) {
		urb = usb_alloc_urb(ISO_FRAMES_PER_DESC, GFP_KERNEL);
		if (urb == NULL) {
			dev_err(&s->udev->dev,
					"Failed to allocate urb %d\n", i);
			msi3101_isoc_cleanup(s);
			return -ENOMEM;
		}
		s->urbs[i] = urb;
		dev_dbg(&s->udev->dev, "Allocated URB at 0x%p\n", urb);

		urb->interval = 1;
		urb->dev = udev;
		urb->pipe = usb_rcvisocpipe(udev, 0x81);
		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
		urb->transfer_buffer = usb_alloc_coherent(udev, ISO_BUFFER_SIZE,
				GFP_KERNEL, &urb->transfer_dma);
		if (urb->transfer_buffer == NULL) {
			dev_err(&s->udev->dev,
					"Failed to allocate urb buffer %d\n",
					i);
			msi3101_isoc_cleanup(s);
			return -ENOMEM;
		}
		urb->transfer_buffer_length = ISO_BUFFER_SIZE;
		urb->complete = msi3101_isoc_handler;
		urb->context = s;
		urb->start_frame = 0;
		urb->number_of_packets = ISO_FRAMES_PER_DESC;
		for (j = 0; j < ISO_FRAMES_PER_DESC; j++) {
			urb->iso_frame_desc[j].offset = j * ISO_MAX_FRAME_SIZE;
			urb->iso_frame_desc[j].length = ISO_MAX_FRAME_SIZE;
		}
	}

	/* link */
	for (i = 0; i < MAX_ISO_BUFS; i++) {
		ret = usb_submit_urb(s->urbs[i], GFP_KERNEL);
		if (ret) {
			dev_err(&s->udev->dev,
					"isoc_init() submit_urb %d failed with error %d\n",
					i, ret);
			msi3101_isoc_cleanup(s);
			return ret;
		}
		dev_dbg(&s->udev->dev, "URB 0x%p submitted.\n", s->urbs[i]);
	}

	/* All is done... */
	return 0;
}

/* Must be called with vb_queue_lock hold */
static void msi3101_cleanup_queued_bufs(struct msi3101_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 msi3101_frame_buf *buf;

		buf = list_entry(s->queued_bufs.next, struct msi3101_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 msi3101_disconnect(struct usb_interface *intf)
{
	struct v4l2_device *v = usb_get_intfdata(intf);
	struct msi3101_state *s =
			container_of(v, struct msi3101_state, v4l2_dev);
	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);
}

static int msi3101_querycap(struct file *file, void *fh,
		struct v4l2_capability *cap)
{
	struct msi3101_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 msi3101_queue_setup(struct vb2_queue *vq,
		const struct v4l2_format *fmt, unsigned int *nbuffers,
		unsigned int *nplanes, unsigned int sizes[], void *alloc_ctxs[])
{
	struct msi3101_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;
	/*
	 *   3, wMaxPacketSize 3x 1024 bytes
	 * 504, max IQ sample pairs per 1024 frame
	 *   2, two samples, I and Q
	 *   4, 32-bit float
	 */
	sizes[0] = PAGE_ALIGN(3 * 504 * 2 * 4); /* = 12096 */
	dev_dbg(&s->udev->dev, "%s: nbuffers=%d sizes[0]=%d\n",
			__func__, *nbuffers, sizes[0]);
	return 0;
}

static int msi3101_buf_prepare(struct vb2_buffer *vb)
{
	struct msi3101_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 msi3101_buf_queue(struct vb2_buffer *vb)
{
	struct msi3101_state *s = vb2_get_drv_priv(vb->vb2_queue);
	struct msi3101_frame_buf *buf =
			container_of(vb, struct msi3101_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);
}

#define CMD_WREG               0x41
#define CMD_START_STREAMING    0x43
#define CMD_STOP_STREAMING     0x45
#define CMD_READ_UNKNOW        0x48

#define msi3101_dbg_usb_control_msg(udev, r, t, v, _i, b, l) { \
	char *direction; \
	if (t == (USB_TYPE_VENDOR | USB_DIR_OUT)) \
		direction = ">>>"; \
	else \
		direction = "<<<"; \
	dev_dbg(&udev->dev, "%s: %02x %02x %02x %02x %02x %02x %02x %02x " \
			"%s %*ph\n",  __func__, t, r, v & 0xff, v >> 8, \
			_i & 0xff, _i >> 8, l & 0xff, l >> 8, direction, l, b); \
}

static int msi3101_ctrl_msg(struct msi3101_state *s, u8 cmd, u32 data)
{
	int ret;
	u8 request = cmd;
	u8 requesttype = USB_DIR_OUT | USB_TYPE_VENDOR;
	u16 value = (data >> 0) & 0xffff;
	u16 index = (data >> 16) & 0xffff;

	msi3101_dbg_usb_control_msg(s->udev,
			request, requesttype, value, index, NULL, 0);

	ret = usb_control_msg(s->udev, usb_sndctrlpipe(s->udev, 0),
			request, requesttype, value, index, NULL, 0, 2000);

	if (ret)
		dev_err(&s->udev->dev, "%s: failed %d, cmd %02x, data %04x\n",
				__func__, ret, cmd, data);

	return ret;
};

static int msi3101_tuner_write(struct msi3101_state *s, u32 data)
{
	return msi3101_ctrl_msg(s, CMD_WREG, data << 8 | 0x09);
};

#define F_REF 24000000
#define DIV_R_IN 2
static int msi3101_set_usb_adc(struct msi3101_state *s)
{
	int ret, div_n, div_m, div_r_out, f_sr, f_vco, fract;
	u32 reg3, reg4, reg7;

	f_sr = s->ctrl_sampling_rate->val64;

	/* select stream format */
	if (f_sr < 6000000) {
		s->convert_stream = msi3101_convert_stream_252;
		reg7 = 0x00009407;
	} else if (f_sr < 8000000) {
		s->convert_stream = msi3101_convert_stream_336;
		reg7 = 0x00008507;
	} else if (f_sr < 9000000) {
		s->convert_stream = msi3101_convert_stream_384;
		reg7 = 0x0000a507;
	} else {
		s->convert_stream = msi3101_convert_stream_504;
		reg7 = 0x000c9407;
	}

	/*
	 * Synthesizer config is just a educated guess...
	 *
	 * [7:0]   0x03, register address
	 * [8]     1, always
	 * [9]     ?
	 * [12:10] output divider
	 * [13]    0 ?
	 * [14]    0 ?
	 * [15]    fractional MSB, bit 20
	 * [16:19] N
	 * [23:20] ?
	 * [24:31] 0x01
	 *
	 * output divider
	 * val   div
	 *   0     - (invalid)
	 *   1     4
	 *   2     6
	 *   3     8
	 *   4    10
	 *   5    12
	 *   6    14
	 *   7    16
	 *
	 * VCO 202000000 - 720000000++
	 */
	reg3 = 0x01000303;
	reg4 = 0x00000004;

	/* XXX: Filters? AGC? */
	if (f_sr < 6000000)
		reg3 |= 0x1 << 20;
	else if (f_sr < 7000000)
		reg3 |= 0x5 << 20;
	else if (f_sr < 8500000)
		reg3 |= 0x9 << 20;
	else
		reg3 |= 0xd << 20;

	for (div_r_out = 4; div_r_out < 16; div_r_out += 2) {
		f_vco = f_sr * div_r_out * 12;
		dev_dbg(&s->udev->dev, "%s: div_r_out=%d f_vco=%d\n",
				__func__, div_r_out, f_vco);
		if (f_vco >= 202000000)
			break;
	}

	div_n = f_vco / (F_REF * DIV_R_IN);
	div_m = f_vco % (F_REF * DIV_R_IN);
	fract = 0x200000ul * div_m / (F_REF * DIV_R_IN);

	reg3 |= div_n << 16;
	reg3 |= (div_r_out / 2 - 1) << 10;
	reg3 |= ((fract >> 20) & 0x000001) << 15; /* [20] */
	reg4 |= ((fract >>  0) & 0x0fffff) <<  8; /* [19:0] */

	dev_dbg(&s->udev->dev,
			"%s: f_sr=%d f_vco=%d div_n=%d div_m=%d div_r_out=%d reg3=%08x reg4=%08x\n",
			__func__, f_sr, f_vco, div_n, div_m, div_r_out, reg3, reg4);

	ret = msi3101_ctrl_msg(s, CMD_WREG, 0x00608008);
	if (ret)
		goto err;

	ret = msi3101_ctrl_msg(s, CMD_WREG, 0x00000c05);
	if (ret)
		goto err;

	ret = msi3101_ctrl_msg(s, CMD_WREG, 0x00020000);
	if (ret)
		goto err;

	ret = msi3101_ctrl_msg(s, CMD_WREG, 0x00480102);
	if (ret)
		goto err;

	ret = msi3101_ctrl_msg(s, CMD_WREG, 0x00f38008);
	if (ret)
		goto err;

	ret = msi3101_ctrl_msg(s, CMD_WREG, reg7);
	if (ret)
		goto err;

	ret = msi3101_ctrl_msg(s, CMD_WREG, reg4);
	if (ret)
		goto err;

	ret = msi3101_ctrl_msg(s, CMD_WREG, reg3);
	if (ret)
		goto err;
err:
	return ret;
};

static int msi3101_set_tuner(struct msi3101_state *s)
{
	int ret, i, len;
	unsigned int n, m, thresh, frac, vco_step, tmp, f_if1;
	u32 reg;
	u64 f_vco, tmp64;
	u8 mode, filter_mode, lo_div;
	const struct msi3101_gain *gain_lut;
	static const struct {
		u32 rf;
		u8 mode;
		u8 lo_div;
	} band_lut[] = {
		{ 50000000, 0xe1, 16}, /* AM_MODE2, antenna 2 */
		{108000000, 0x42, 32}, /* VHF_MODE */
		{330000000, 0x44, 16}, /* B3_MODE */
		{960000000, 0x48,  4}, /* B45_MODE */
		{      ~0U, 0x50,  2}, /* BL_MODE */
	};
	static const struct {
		u32 freq;
		u8 filter_mode;
	} if_freq_lut[] = {
		{      0, 0x03}, /* Zero IF */
		{ 450000, 0x02}, /* 450 kHz IF */
		{1620000, 0x01}, /* 1.62 MHz IF */
		{2048000, 0x00}, /* 2.048 MHz IF */
	};
	static const struct {
		u32 freq;
		u8 val;
	} bandwidth_lut[] = {
		{ 200000, 0x00}, /* 200 kHz */
		{ 300000, 0x01}, /* 300 kHz */
		{ 600000, 0x02}, /* 600 kHz */
		{1536000, 0x03}, /* 1.536 MHz */
		{5000000, 0x04}, /* 5 MHz */
		{6000000, 0x05}, /* 6 MHz */
		{7000000, 0x06}, /* 7 MHz */
		{8000000, 0x07}, /* 8 MHz */
	};

	unsigned int f_rf = s->ctrl_tuner_rf->val64;

	/*
	 * bandwidth (Hz)
	 * 200000, 300000, 600000, 1536000, 5000000, 6000000, 7000000, 8000000
	 */
	unsigned int bandwidth = s->ctrl_tuner_bw->val;

	/*
	 * intermediate frequency (Hz)
	 * 0, 450000, 1620000, 2048000
	 */
	unsigned int f_if = s->ctrl_tuner_if->val;

	/*
	 * gain reduction (dB)
	 * 0 - 102 below 420 MHz
	 * 0 - 85 above 420 MHz
	 */
	int gain = s->ctrl_tuner_gain->val;

	dev_dbg(&s->udev->dev,
			"%s: f_rf=%d bandwidth=%d f_if=%d gain=%d\n",
			__func__, f_rf, bandwidth, f_if, gain);

	ret = -EINVAL;

	for (i = 0; i < ARRAY_SIZE(band_lut); i++) {
		if (f_rf <= band_lut[i].rf) {
			mode = band_lut[i].mode;
			lo_div = band_lut[i].lo_div;
			break;
		}
	}

	if (i == ARRAY_SIZE(band_lut))
		goto err;

	/* AM_MODE is upconverted */
	if ((mode >> 0) & 0x1)
		f_if1 =  5 * F_REF;
	else
		f_if1 =  0;

	for (i = 0; i < ARRAY_SIZE(if_freq_lut); i++) {
		if (f_if == if_freq_lut[i].freq) {
			filter_mode = if_freq_lut[i].filter_mode;
			break;
		}
	}

	if (i == ARRAY_SIZE(if_freq_lut))
		goto err;

	for (i = 0; i < ARRAY_SIZE(bandwidth_lut); i++) {
		if (bandwidth == bandwidth_lut[i].freq) {
			bandwidth = bandwidth_lut[i].val;
			break;
		}
	}

	if (i == ARRAY_SIZE(bandwidth_lut))
		goto err;

#define F_OUT_STEP 1
#define R_REF 4
	f_vco = (f_rf + f_if + f_if1) * lo_div;

	tmp64 = f_vco;
	m = do_div(tmp64, F_REF * R_REF);
	n = (unsigned int) tmp64;

	vco_step = F_OUT_STEP * lo_div;
	thresh = (F_REF * R_REF) / vco_step;
	frac = 1ul * thresh * m / (F_REF * R_REF);

	/* Find out greatest common divisor and divide to smaller. */
	tmp = gcd(thresh, frac);
	thresh /= tmp;
	frac /= tmp;

	/* Force divide to reg max. Resolution will be reduced. */
	tmp = DIV_ROUND_UP(thresh, 4095);
	thresh = DIV_ROUND_CLOSEST(thresh, tmp);
	frac = DIV_ROUND_CLOSEST(frac, tmp);

	/* calc real RF set */
	tmp = 1ul * F_REF * R_REF * n;
	tmp += 1ul * F_REF * R_REF * frac / thresh;
	tmp /= lo_div;

	dev_dbg(&s->udev->dev,
			"%s: rf=%u:%u n=%d thresh=%d frac=%d\n",
				__func__, f_rf, tmp, n, thresh, frac);

	ret = msi3101_tuner_write(s, 0x00000e);
	if (ret)
		goto err;

	ret = msi3101_tuner_write(s, 0x000003);
	if (ret)
		goto err;

	reg = 0 << 0;
	reg |= mode << 4;
	reg |= filter_mode << 12;
	reg |= bandwidth << 14;
	reg |= 0x02 << 17;
	reg |= 0x00 << 20;
	ret = msi3101_tuner_write(s, reg);
	if (ret)
		goto err;

	reg = 5 << 0;
	reg |= thresh << 4;
	reg |= 1 << 19;
	reg |= 1 << 21;
	ret = msi3101_tuner_write(s, reg);
	if (ret)
		goto err;

	reg = 2 << 0;
	reg |= frac << 4;
	reg |= n << 16;
	ret = msi3101_tuner_write(s, reg);
	if (ret)
		goto err;

	if (f_rf < 120000000) {
		gain_lut = msi3101_gain_lut_120;
		len = ARRAY_SIZE(msi3101_gain_lut_120);
	} else if (f_rf < 245000000) {
		gain_lut = msi3101_gain_lut_245;
		len = ARRAY_SIZE(msi3101_gain_lut_120);
	} else {
		gain_lut = msi3101_gain_lut_1000;
		len = ARRAY_SIZE(msi3101_gain_lut_1000);
	}

	for (i = 0; i < len; i++) {
		if (gain_lut[i].tot >= gain)
			break;
	}

	if (i == len)
		goto err;

	dev_dbg(&s->udev->dev,
			"%s: gain tot=%d baseband=%d lna=%d mixer=%d\n",
			__func__, gain_lut[i].tot, gain_lut[i].baseband,
			gain_lut[i].lna, gain_lut[i].mixer);

	reg = 1 << 0;
	reg |= gain_lut[i].baseband << 4;
	reg |= 0 << 10;
	reg |= gain_lut[i].mixer << 12;
	reg |= gain_lut[i].lna << 13;
	reg |= 4 << 14;
	reg |= 0 << 17;
	ret = msi3101_tuner_write(s, reg);
	if (ret)
		goto err;

	reg = 6 << 0;
	reg |= 63 << 4;
	reg |= 4095 << 10;
	ret = msi3101_tuner_write(s, reg);
	if (ret)
		goto err;

	return 0;
err:
	dev_dbg(&s->udev->dev, "%s: failed %d\n", __func__, ret);
	return ret;
};

static int msi3101_start_streaming(struct vb2_queue *vq, unsigned int count)
{
	struct msi3101_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;

	ret = msi3101_set_usb_adc(s);

	ret = msi3101_isoc_init(s);
	if (ret)
		msi3101_cleanup_queued_bufs(s);

	ret = msi3101_ctrl_msg(s, CMD_START_STREAMING, 0);

	mutex_unlock(&s->v4l2_lock);

	return ret;
}

static int msi3101_stop_streaming(struct vb2_queue *vq)
{
	struct msi3101_state *s = vb2_get_drv_priv(vq);
	dev_dbg(&s->udev->dev, "%s:\n", __func__);

	if (mutex_lock_interruptible(&s->v4l2_lock))
		return -ERESTARTSYS;

	if (s->udev)
		msi3101_isoc_cleanup(s);

	msi3101_cleanup_queued_bufs(s);

	/* according to tests, at least 700us delay is required  */
	msleep(20);
	msi3101_ctrl_msg(s, CMD_STOP_STREAMING, 0);

	mutex_unlock(&s->v4l2_lock);

	return 0;
}

static struct vb2_ops msi3101_vb2_ops = {
	.queue_setup            = msi3101_queue_setup,
	.buf_prepare            = msi3101_buf_prepare,
	.buf_queue              = msi3101_buf_queue,
	.start_streaming        = msi3101_start_streaming,
	.stop_streaming         = msi3101_stop_streaming,
	.wait_prepare           = vb2_ops_wait_prepare,
	.wait_finish            = vb2_ops_wait_finish,
};

static int msi3101_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 msi3101_g_input(struct file *file, void *fh, unsigned int *i)
{
	*i = 0;

	return 0;
}

static int msi3101_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 msi3101_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 msi3101_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 msi3101_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 msi3101_ioctl_ops = {
	.vidioc_querycap          = msi3101_querycap,

	.vidioc_enum_input        = msi3101_enum_input,
	.vidioc_g_input           = msi3101_g_input,
	.vidioc_s_input           = msi3101_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 msi3101_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 msi3101_template = {
	.name                     = "Mirics MSi3101 SDR Dongle",
	.release                  = video_device_release_empty,
	.fops                     = &msi3101_fops,
	.ioctl_ops                = &msi3101_ioctl_ops,
};

static int msi3101_s_ctrl(struct v4l2_ctrl *ctrl)
{
	struct msi3101_state *s =
			container_of(ctrl->handler, struct msi3101_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 MSI3101_CID_SAMPLING_MODE:
	case MSI3101_CID_SAMPLING_RATE:
	case MSI3101_CID_SAMPLING_RESOLUTION:
		ret = 0;
		break;
	case MSI3101_CID_TUNER_RF:
	case MSI3101_CID_TUNER_BW:
	case MSI3101_CID_TUNER_IF:
	case MSI3101_CID_TUNER_GAIN:
		ret = msi3101_set_tuner(s);
		break;
	default:
		ret = -EINVAL;
	}

	return ret;
}

static const struct v4l2_ctrl_ops msi3101_ctrl_ops = {
	.s_ctrl = msi3101_s_ctrl,
};

static void msi3101_video_release(struct v4l2_device *v)
{
	struct msi3101_state *s =
			container_of(v, struct msi3101_state, v4l2_dev);

	v4l2_ctrl_handler_free(&s->ctrl_handler);
	v4l2_device_unregister(&s->v4l2_dev);
	kfree(s);
}

static int msi3101_probe(struct usb_interface *intf,
		const struct usb_device_id *id)
{
	struct usb_device *udev = interface_to_usbdev(intf);
	struct msi3101_state *s = NULL;
	int ret;
	static const char * const ctrl_sampling_mode_qmenu_strings[] = {
		"Quadrature Sampling",
		NULL,
	};
	static const struct v4l2_ctrl_config ctrl_sampling_mode = {
		.ops	= &msi3101_ctrl_ops,
		.id	= MSI3101_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	= &msi3101_ctrl_ops,
		.id	= MSI3101_CID_SAMPLING_RATE,
		.type	= V4L2_CTRL_TYPE_INTEGER64,
		.name	= "Sampling Rate",
		.min	= 500000,
		.max	= 12000000,
		.def    = 2048000,
		.step	= 1,
	};
	static const struct v4l2_ctrl_config ctrl_sampling_resolution = {
		.ops	= &msi3101_ctrl_ops,
		.id	= MSI3101_CID_SAMPLING_RESOLUTION,
		.type	= V4L2_CTRL_TYPE_INTEGER,
		.flags  = V4L2_CTRL_FLAG_INACTIVE,
		.name	= "Sampling Resolution",
		.min	= 10,
		.max	= 10,
		.def    = 10,
		.step	= 1,
	};
	static const struct v4l2_ctrl_config ctrl_tuner_rf = {
		.ops	= &msi3101_ctrl_ops,
		.id	= MSI3101_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	= &msi3101_ctrl_ops,
		.id	= MSI3101_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	= &msi3101_ctrl_ops,
		.id	= MSI3101_CID_TUNER_IF,
		.type	= V4L2_CTRL_TYPE_INTEGER,
		.flags  = V4L2_CTRL_FLAG_INACTIVE,
		.name	= "Tuner IF",
		.min	= 0,
		.max	= 2048000,
		.def    = 0,
		.step	= 1,
	};
	static const struct v4l2_ctrl_config ctrl_tuner_gain = {
		.ops	= &msi3101_ctrl_ops,
		.id	= MSI3101_CID_TUNER_GAIN,
		.type	= V4L2_CTRL_TYPE_INTEGER,
		.name	= "Tuner Gain",
		.min	= 0,
		.max	= 102,
		.def    = 0,
		.step	= 1,
	};

	s = kzalloc(sizeof(struct msi3101_state), GFP_KERNEL);
	if (s == NULL) {
		pr_err("Could not allocate memory for msi3101_state\n");
		return -ENOMEM;
	}

	mutex_init(&s->v4l2_lock);
	mutex_init(&s->vb_queue_lock);
	spin_lock_init(&s->queued_bufs_lock);
	INIT_LIST_HEAD(&s->queued_bufs);

	s->udev = udev;

	/* 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 msi3101_frame_buf);
	s->vb_queue.ops = &msi3101_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 = msi3101_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 = msi3101_video_release;
	ret = v4l2_device_register(&intf->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));

	return 0;

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 ret;
}

/* USB device ID list */
static struct usb_device_id msi3101_id_table[] = {
	{ USB_DEVICE(0x1df7, 0x2500) }, /* Mirics MSi3101 SDR Dongle */
	{ USB_DEVICE(0x2040, 0xd300) }, /* Hauppauge WinTV 133559 LF */
	{ }
};
MODULE_DEVICE_TABLE(usb, msi3101_id_table);

/* USB subsystem interface */
static struct usb_driver msi3101_driver = {
	.name                     = KBUILD_MODNAME,
	.probe                    = msi3101_probe,
	.disconnect               = msi3101_disconnect,
	.id_table                 = msi3101_id_table,
};

module_usb_driver(msi3101_driver);

MODULE_AUTHOR("Antti Palosaari <crope@iki.fi>");
MODULE_DESCRIPTION("Mirics MSi3101 SDR Dongle");
MODULE_LICENSE("GPL");