drivers/media/usb/em28xx/em28xx-dvb.c

/*
 DVB device driver for em28xx

 (c) 2008-2011 Mauro Carvalho Chehab <mchehab@infradead.org>

 (c) 2008 Devin Heitmueller <devin.heitmueller@gmail.com>
	- Fixes for the driver to properly work with HVR-950
	- Fixes for the driver to properly work with Pinnacle PCTV HD Pro Stick
	- Fixes for the driver to properly work with AMD ATI TV Wonder HD 600

 (c) 2008 Aidan Thornton <makosoft@googlemail.com>

 (c) 2012 Frank Schäfer <fschaefer.oss@googlemail.com>

 Based on cx88-dvb, saa7134-dvb and videobuf-dvb originally written by:
	(c) 2004, 2005 Chris Pascoe <c.pascoe@itee.uq.edu.au>
	(c) 2004 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]

 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.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/usb.h>

#include "em28xx.h"
#include <media/v4l2-common.h>
#include <media/videobuf-vmalloc.h>
#include <media/tuner.h>
#include "tuner-simple.h"
#include <linux/gpio.h>

#include "lgdt330x.h"
#include "lgdt3305.h"
#include "zl10353.h"
#include "s5h1409.h"
#include "mt352.h"
#include "mt352_priv.h" /* FIXME */
#include "tda1002x.h"
#include "tda18271.h"
#include "s921.h"
#include "drxd.h"
#include "cxd2820r.h"
#include "tda18271c2dd.h"
#include "drxk.h"
#include "tda10071.h"
#include "a8293.h"
#include "qt1010.h"

MODULE_DESCRIPTION("driver for em28xx based DVB cards");
MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
MODULE_LICENSE("GPL");

static unsigned int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "enable debug messages [dvb]");

DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);

#define dprintk(level, fmt, arg...) do {			\
if (debug >= level) 						\
	printk(KERN_DEBUG "%s/2-dvb: " fmt, dev->name, ## arg);	\
} while (0)

struct em28xx_dvb {
	struct dvb_frontend        *fe[2];

	/* feed count management */
	struct mutex               lock;
	int                        nfeeds;

	/* general boilerplate stuff */
	struct dvb_adapter         adapter;
	struct dvb_demux           demux;
	struct dmxdev              dmxdev;
	struct dmx_frontend        fe_hw;
	struct dmx_frontend        fe_mem;
	struct dvb_net             net;

	/* Due to DRX-K - probably need changes */
	int (*gate_ctrl)(struct dvb_frontend *, int);
	struct semaphore      pll_mutex;
	bool			dont_attach_fe1;
	int			lna_gpio;
};


static inline void print_err_status(struct em28xx *dev,
				     int packet, int status)
{
	char *errmsg = "Unknown";

	switch (status) {
	case -ENOENT:
		errmsg = "unlinked synchronuously";
		break;
	case -ECONNRESET:
		errmsg = "unlinked asynchronuously";
		break;
	case -ENOSR:
		errmsg = "Buffer error (overrun)";
		break;
	case -EPIPE:
		errmsg = "Stalled (device not responding)";
		break;
	case -EOVERFLOW:
		errmsg = "Babble (bad cable?)";
		break;
	case -EPROTO:
		errmsg = "Bit-stuff error (bad cable?)";
		break;
	case -EILSEQ:
		errmsg = "CRC/Timeout (could be anything)";
		break;
	case -ETIME:
		errmsg = "Device does not respond";
		break;
	}
	if (packet < 0) {
		dprintk(1, "URB status %d [%s].\n", status, errmsg);
	} else {
		dprintk(1, "URB packet %d, status %d [%s].\n",
			packet, status, errmsg);
	}
}

static inline int em28xx_dvb_urb_data_copy(struct em28xx *dev, struct urb *urb)
{
	int xfer_bulk, num_packets, i;

	if (!dev)
		return 0;

	if ((dev->state & DEV_DISCONNECTED) || (dev->state & DEV_MISCONFIGURED))
		return 0;

	if (urb->status < 0)
		print_err_status(dev, -1, urb->status);

	xfer_bulk = usb_pipebulk(urb->pipe);

	if (xfer_bulk) /* bulk */
		num_packets = 1;
	else /* isoc */
		num_packets = urb->number_of_packets;

	for (i = 0; i < num_packets; i++) {
		if (xfer_bulk) {
			if (urb->status < 0) {
				print_err_status(dev, i, urb->status);
				if (urb->status != -EPROTO)
					continue;
			}
			dvb_dmx_swfilter(&dev->dvb->demux, urb->transfer_buffer,
					urb->actual_length);
		} else {
			if (urb->iso_frame_desc[i].status < 0) {
				print_err_status(dev, i,
						 urb->iso_frame_desc[i].status);
				if (urb->iso_frame_desc[i].status != -EPROTO)
					continue;
			}
			dvb_dmx_swfilter(&dev->dvb->demux,
					 urb->transfer_buffer +
					 urb->iso_frame_desc[i].offset,
					 urb->iso_frame_desc[i].actual_length);
		}
	}

	return 0;
}

static int em28xx_start_streaming(struct em28xx_dvb *dvb)
{
	int rc;
	struct em28xx *dev = dvb->adapter.priv;
	int max_dvb_packet_size;

	usb_set_interface(dev->udev, 0, dev->dvb_alt);
	rc = em28xx_set_mode(dev, EM28XX_DIGITAL_MODE);
	if (rc < 0)
		return rc;

	max_dvb_packet_size = dev->dvb_max_pkt_size;
	if (max_dvb_packet_size < 0)
		return max_dvb_packet_size;
	dprintk(1, "Using %d buffers each with %d x %d bytes\n",
		EM28XX_DVB_NUM_BUFS,
		EM28XX_DVB_NUM_ISOC_PACKETS,
		max_dvb_packet_size);

	return em28xx_init_usb_xfer(dev, EM28XX_DIGITAL_MODE, 0,
				    EM28XX_DVB_NUM_BUFS,
				    max_dvb_packet_size,
				    EM28XX_DVB_NUM_ISOC_PACKETS,
				    em28xx_dvb_urb_data_copy);
}

static int em28xx_stop_streaming(struct em28xx_dvb *dvb)
{
	struct em28xx *dev = dvb->adapter.priv;

	em28xx_stop_urbs(dev);

	em28xx_set_mode(dev, EM28XX_SUSPEND);

	return 0;
}

static int em28xx_start_feed(struct dvb_demux_feed *feed)
{
	struct dvb_demux *demux  = feed->demux;
	struct em28xx_dvb *dvb = demux->priv;
	int rc, ret;

	if (!demux->dmx.frontend)
		return -EINVAL;

	mutex_lock(&dvb->lock);
	dvb->nfeeds++;
	rc = dvb->nfeeds;

	if (dvb->nfeeds == 1) {
		ret = em28xx_start_streaming(dvb);
		if (ret < 0)
			rc = ret;
	}

	mutex_unlock(&dvb->lock);
	return rc;
}

static int em28xx_stop_feed(struct dvb_demux_feed *feed)
{
	struct dvb_demux *demux  = feed->demux;
	struct em28xx_dvb *dvb = demux->priv;
	int err = 0;

	mutex_lock(&dvb->lock);
	dvb->nfeeds--;

	if (0 == dvb->nfeeds)
		err = em28xx_stop_streaming(dvb);

	mutex_unlock(&dvb->lock);
	return err;
}



/* ------------------------------------------------------------------ */
static int em28xx_dvb_bus_ctrl(struct dvb_frontend *fe, int acquire)
{
	struct em28xx *dev = fe->dvb->priv;

	if (acquire)
		return em28xx_set_mode(dev, EM28XX_DIGITAL_MODE);
	else
		return em28xx_set_mode(dev, EM28XX_SUSPEND);
}

/* ------------------------------------------------------------------ */

static struct lgdt330x_config em2880_lgdt3303_dev = {
	.demod_address = 0x0e,
	.demod_chip = LGDT3303,
};

static struct lgdt3305_config em2870_lgdt3304_dev = {
	.i2c_addr           = 0x0e,
	.demod_chip         = LGDT3304,
	.spectral_inversion = 1,
	.deny_i2c_rptr      = 1,
	.mpeg_mode          = LGDT3305_MPEG_PARALLEL,
	.tpclk_edge         = LGDT3305_TPCLK_FALLING_EDGE,
	.tpvalid_polarity   = LGDT3305_TP_VALID_HIGH,
	.vsb_if_khz         = 3250,
	.qam_if_khz         = 4000,
};

static struct s921_config sharp_isdbt = {
	.demod_address = 0x30 >> 1
};

static struct zl10353_config em28xx_zl10353_with_xc3028 = {
	.demod_address = (0x1e >> 1),
	.no_tuner = 1,
	.parallel_ts = 1,
	.if2 = 45600,
};

static struct s5h1409_config em28xx_s5h1409_with_xc3028 = {
	.demod_address = 0x32 >> 1,
	.output_mode   = S5H1409_PARALLEL_OUTPUT,
	.gpio          = S5H1409_GPIO_OFF,
	.inversion     = S5H1409_INVERSION_OFF,
	.status_mode   = S5H1409_DEMODLOCKING,
	.mpeg_timing   = S5H1409_MPEGTIMING_CONTINOUS_NONINVERTING_CLOCK
};

static struct tda18271_std_map kworld_a340_std_map = {
	.atsc_6   = { .if_freq = 3250, .agc_mode = 3, .std = 0,
		      .if_lvl = 1, .rfagc_top = 0x37, },
	.qam_6    = { .if_freq = 4000, .agc_mode = 3, .std = 1,
		      .if_lvl = 1, .rfagc_top = 0x37, },
};

static struct tda18271_config kworld_a340_config = {
	.std_map           = &kworld_a340_std_map,
};

static struct zl10353_config em28xx_zl10353_xc3028_no_i2c_gate = {
	.demod_address = (0x1e >> 1),
	.no_tuner = 1,
	.disable_i2c_gate_ctrl = 1,
	.parallel_ts = 1,
	.if2 = 45600,
};

static struct drxd_config em28xx_drxd = {
	.demod_address = 0x70,
	.demod_revision = 0xa2,
	.pll_type = DRXD_PLL_NONE,
	.clock = 12000,
	.insert_rs_byte = 1,
	.IF = 42800000,
	.disable_i2c_gate_ctrl = 1,
};

static struct drxk_config terratec_h5_drxk = {
	.adr = 0x29,
	.single_master = 1,
	.no_i2c_bridge = 1,
	.microcode_name = "dvb-usb-terratec-h5-drxk.fw",
	.qam_demod_parameter_count = 2,
	.load_firmware_sync = true,
};

static struct drxk_config hauppauge_930c_drxk = {
	.adr = 0x29,
	.single_master = 1,
	.no_i2c_bridge = 1,
	.microcode_name = "dvb-usb-hauppauge-hvr930c-drxk.fw",
	.chunk_size = 56,
	.qam_demod_parameter_count = 2,
	.load_firmware_sync = true,
};

static struct drxk_config terratec_htc_stick_drxk = {
	.adr = 0x29,
	.single_master = 1,
	.no_i2c_bridge = 1,
	.microcode_name = "dvb-usb-terratec-htc-stick-drxk.fw",
	.chunk_size = 54,
	.qam_demod_parameter_count = 2,
	/* Required for the antenna_gpio to disable LNA. */
	.antenna_dvbt = true,
	/* The windows driver uses the same. This will disable LNA. */
	.antenna_gpio = 0x6,
	.load_firmware_sync = true,
};

static struct drxk_config maxmedia_ub425_tc_drxk = {
	.adr = 0x29,
	.single_master = 1,
	.no_i2c_bridge = 1,
	.load_firmware_sync = true,
};

static struct drxk_config pctv_520e_drxk = {
	.adr = 0x29,
	.single_master = 1,
	.microcode_name = "dvb-demod-drxk-pctv.fw",
	.qam_demod_parameter_count = 2,
	.chunk_size = 58,
	.antenna_dvbt = true, /* disable LNA */
	.antenna_gpio = (1 << 2), /* disable LNA */
	.load_firmware_sync = true,
};

static int drxk_gate_ctrl(struct dvb_frontend *fe, int enable)
{
	struct em28xx_dvb *dvb = fe->sec_priv;
	int status;

	if (!dvb)
		return -EINVAL;

	if (enable) {
		down(&dvb->pll_mutex);
		status = dvb->gate_ctrl(fe, 1);
	} else {
		status = dvb->gate_ctrl(fe, 0);
		up(&dvb->pll_mutex);
	}
	return status;
}

static void hauppauge_hvr930c_init(struct em28xx *dev)
{
	int i;

	struct em28xx_reg_seq hauppauge_hvr930c_init[] = {
		{EM2874_R80_GPIO,	0xff,	0xff,	0x65},
		{EM2874_R80_GPIO,	0xfb,	0xff,	0x32},
		{EM2874_R80_GPIO,	0xff,	0xff,	0xb8},
		{ -1,                   -1,     -1,     -1},
	};
	struct em28xx_reg_seq hauppauge_hvr930c_end[] = {
		{EM2874_R80_GPIO,	0xef,	0xff,	0x01},
		{EM2874_R80_GPIO,	0xaf,	0xff,	0x65},
		{EM2874_R80_GPIO,	0xef,	0xff,	0x76},
		{EM2874_R80_GPIO,	0xef,	0xff,	0x01},
		{EM2874_R80_GPIO,	0xcf,	0xff,	0x0b},
		{EM2874_R80_GPIO,	0xef,	0xff,	0x40},

		{EM2874_R80_GPIO,	0xcf,	0xff,	0x65},
		{EM2874_R80_GPIO,	0xef,	0xff,	0x65},
		{EM2874_R80_GPIO,	0xcf,	0xff,	0x0b},
		{EM2874_R80_GPIO,	0xef,	0xff,	0x65},

		{ -1,                   -1,     -1,     -1},
	};

	struct {
		unsigned char r[4];
		int len;
	} regs[] = {
		{{ 0x06, 0x02, 0x00, 0x31 }, 4},
		{{ 0x01, 0x02 }, 2},
		{{ 0x01, 0x02, 0x00, 0xc6 }, 4},
		{{ 0x01, 0x00 }, 2},
		{{ 0x01, 0x00, 0xff, 0xaf }, 4},
		{{ 0x01, 0x00, 0x03, 0xa0 }, 4},
		{{ 0x01, 0x00 }, 2},
		{{ 0x01, 0x00, 0x73, 0xaf }, 4},
		{{ 0x04, 0x00 }, 2},
		{{ 0x00, 0x04 }, 2},
		{{ 0x00, 0x04, 0x00, 0x0a }, 4},
		{{ 0x04, 0x14 }, 2},
		{{ 0x04, 0x14, 0x00, 0x00 }, 4},
	};

	em28xx_gpio_set(dev, hauppauge_hvr930c_init);
	em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x40);
	msleep(10);
	em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x44);
	msleep(10);

	dev->i2c_client.addr = 0x82 >> 1;

	for (i = 0; i < ARRAY_SIZE(regs); i++)
		i2c_master_send(&dev->i2c_client, regs[i].r, regs[i].len);
	em28xx_gpio_set(dev, hauppauge_hvr930c_end);

	msleep(100);

	em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x44);
	msleep(30);

	em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x45);
	msleep(10);

}

static void terratec_h5_init(struct em28xx *dev)
{
	int i;
	struct em28xx_reg_seq terratec_h5_init[] = {
		{EM28XX_R08_GPIO,	0xff,	0xff,	10},
		{EM2874_R80_GPIO,	0xf6,	0xff,	100},
		{EM2874_R80_GPIO,	0xf2,	0xff,	50},
		{EM2874_R80_GPIO,	0xf6,	0xff,	100},
		{ -1,                   -1,     -1,     -1},
	};
	struct em28xx_reg_seq terratec_h5_end[] = {
		{EM2874_R80_GPIO,	0xe6,	0xff,	100},
		{EM2874_R80_GPIO,	0xa6,	0xff,	50},
		{EM2874_R80_GPIO,	0xe6,	0xff,	100},
		{ -1,                   -1,     -1,     -1},
	};
	struct {
		unsigned char r[4];
		int len;
	} regs[] = {
		{{ 0x06, 0x02, 0x00, 0x31 }, 4},
		{{ 0x01, 0x02 }, 2},
		{{ 0x01, 0x02, 0x00, 0xc6 }, 4},
		{{ 0x01, 0x00 }, 2},
		{{ 0x01, 0x00, 0xff, 0xaf }, 4},
		{{ 0x01, 0x00, 0x03, 0xa0 }, 4},
		{{ 0x01, 0x00 }, 2},
		{{ 0x01, 0x00, 0x73, 0xaf }, 4},
		{{ 0x04, 0x00 }, 2},
		{{ 0x00, 0x04 }, 2},
		{{ 0x00, 0x04, 0x00, 0x0a }, 4},
		{{ 0x04, 0x14 }, 2},
		{{ 0x04, 0x14, 0x00, 0x00 }, 4},
	};

	em28xx_gpio_set(dev, terratec_h5_init);
	em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x40);
	msleep(10);
	em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x45);
	msleep(10);

	dev->i2c_client.addr = 0x82 >> 1;

	for (i = 0; i < ARRAY_SIZE(regs); i++)
		i2c_master_send(&dev->i2c_client, regs[i].r, regs[i].len);
	em28xx_gpio_set(dev, terratec_h5_end);
};

static void terratec_htc_stick_init(struct em28xx *dev)
{
	int i;

	/*
	 * GPIO configuration:
	 * 0xff: unknown (does not affect DVB-T).
	 * 0xf6: DRX-K (demodulator).
	 * 0xe6: unknown (does not affect DVB-T).
	 * 0xb6: unknown (does not affect DVB-T).
	 */
	struct em28xx_reg_seq terratec_htc_stick_init[] = {
		{EM28XX_R08_GPIO,	0xff,	0xff,	10},
		{EM2874_R80_GPIO,	0xf6,	0xff,	100},
		{EM2874_R80_GPIO,	0xe6,	0xff,	50},
		{EM2874_R80_GPIO,	0xf6,	0xff,	100},
		{ -1,                   -1,     -1,     -1},
	};
	struct em28xx_reg_seq terratec_htc_stick_end[] = {
		{EM2874_R80_GPIO,	0xb6,	0xff,	100},
		{EM2874_R80_GPIO,	0xf6,	0xff,	50},
		{ -1,                   -1,     -1,     -1},
	};

	/*
	 * Init the analog decoder (not yet supported), but
	 * it's probably still a good idea.
	 */
	struct {
		unsigned char r[4];
		int len;
	} regs[] = {
		{{ 0x06, 0x02, 0x00, 0x31 }, 4},
		{{ 0x01, 0x02 }, 2},
		{{ 0x01, 0x02, 0x00, 0xc6 }, 4},
		{{ 0x01, 0x00 }, 2},
		{{ 0x01, 0x00, 0xff, 0xaf }, 4},
	};

	em28xx_gpio_set(dev, terratec_htc_stick_init);

	em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x40);
	msleep(10);
	em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x44);
	msleep(10);

	dev->i2c_client.addr = 0x82 >> 1;

	for (i = 0; i < ARRAY_SIZE(regs); i++)
		i2c_master_send(&dev->i2c_client, regs[i].r, regs[i].len);

	em28xx_gpio_set(dev, terratec_htc_stick_end);
};

static void terratec_htc_usb_xs_init(struct em28xx *dev)
{
	int i;

	struct em28xx_reg_seq terratec_htc_usb_xs_init[] = {
		{EM28XX_R08_GPIO,	0xff,	0xff,	10},
		{EM2874_R80_GPIO,	0xb2,	0xff,	100},
		{EM2874_R80_GPIO,	0xb2,	0xff,	50},
		{EM2874_R80_GPIO,	0xb6,	0xff,	100},
		{ -1,                   -1,     -1,     -1},
	};
	struct em28xx_reg_seq terratec_htc_usb_xs_end[] = {
		{EM2874_R80_GPIO,	0xa6,	0xff,	100},
		{EM2874_R80_GPIO,	0xa6,	0xff,	50},
		{EM2874_R80_GPIO,	0xe6,	0xff,	100},
		{ -1,                   -1,     -1,     -1},
	};

	/*
	 * Init the analog decoder (not yet supported), but
	 * it's probably still a good idea.
	 */
	struct {
		unsigned char r[4];
		int len;
	} regs[] = {
		{{ 0x06, 0x02, 0x00, 0x31 }, 4},
		{{ 0x01, 0x02 }, 2},
		{{ 0x01, 0x02, 0x00, 0xc6 }, 4},
		{{ 0x01, 0x00 }, 2},
		{{ 0x01, 0x00, 0xff, 0xaf }, 4},
		{{ 0x01, 0x00, 0x03, 0xa0 }, 4},
		{{ 0x01, 0x00 }, 2},
		{{ 0x01, 0x00, 0x73, 0xaf }, 4},
		{{ 0x04, 0x00 }, 2},
		{{ 0x00, 0x04 }, 2},
		{{ 0x00, 0x04, 0x00, 0x0a }, 4},
		{{ 0x04, 0x14 }, 2},
		{{ 0x04, 0x14, 0x00, 0x00 }, 4},
	};

	em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x40);

	em28xx_gpio_set(dev, terratec_htc_usb_xs_init);

	em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x40);
	msleep(10);
	em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, 0x44);
	msleep(10);

	dev->i2c_client.addr = 0x82 >> 1;

	for (i = 0; i < ARRAY_SIZE(regs); i++)
		i2c_master_send(&dev->i2c_client, regs[i].r, regs[i].len);

	em28xx_gpio_set(dev, terratec_htc_usb_xs_end);
};

static void pctv_520e_init(struct em28xx *dev)
{
	/*
	 * Init AVF4910B analog decoder. Looks like I2C traffic to
	 * digital demodulator and tuner are routed via AVF4910B.
	 */
	int i;
	struct {
		unsigned char r[4];
		int len;
	} regs[] = {
		{{ 0x06, 0x02, 0x00, 0x31 }, 4},
		{{ 0x01, 0x02 }, 2},
		{{ 0x01, 0x02, 0x00, 0xc6 }, 4},
		{{ 0x01, 0x00 }, 2},
		{{ 0x01, 0x00, 0xff, 0xaf }, 4},
		{{ 0x01, 0x00, 0x03, 0xa0 }, 4},
		{{ 0x01, 0x00 }, 2},
		{{ 0x01, 0x00, 0x73, 0xaf }, 4},
	};

	dev->i2c_client.addr = 0x82 >> 1; /* 0x41 */

	for (i = 0; i < ARRAY_SIZE(regs); i++)
		i2c_master_send(&dev->i2c_client, regs[i].r, regs[i].len);
};

static int em28xx_pctv_290e_set_lna(struct dvb_frontend *fe)
{
	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
	struct em28xx *dev = fe->dvb->priv;
#ifdef CONFIG_GPIOLIB
	struct em28xx_dvb *dvb = dev->dvb;
	int ret;
	unsigned long flags;

	if (c->lna == 1)
		flags = GPIOF_OUT_INIT_HIGH; /* enable LNA */
	else
		flags = GPIOF_OUT_INIT_LOW; /* disable LNA */

	ret = gpio_request_one(dvb->lna_gpio, flags, NULL);
	if (ret)
		em28xx_errdev("gpio request failed %d\n", ret);
	else
		gpio_free(dvb->lna_gpio);

	return ret;
#else
	dev_warn(&dev->udev->dev, "%s: LNA control is disabled (lna=%u)\n",
			KBUILD_MODNAME, c->lna);
	return 0;
#endif
}

static int em28xx_mt352_terratec_xs_init(struct dvb_frontend *fe)
{
	/* Values extracted from a USB trace of the Terratec Windows driver */
	static u8 clock_config[]   = { CLOCK_CTL,  0x38, 0x2c };
	static u8 reset[]          = { RESET,      0x80 };
	static u8 adc_ctl_1_cfg[]  = { ADC_CTL_1,  0x40 };
	static u8 agc_cfg[]        = { AGC_TARGET, 0x28, 0xa0 };
	static u8 input_freq_cfg[] = { INPUT_FREQ_1, 0x31, 0xb8 };
	static u8 rs_err_cfg[]     = { RS_ERR_PER_1, 0x00, 0x4d };
	static u8 capt_range_cfg[] = { CAPT_RANGE, 0x32 };
	static u8 trl_nom_cfg[]    = { TRL_NOMINAL_RATE_1, 0x64, 0x00 };
	static u8 tps_given_cfg[]  = { TPS_GIVEN_1, 0x40, 0x80, 0x50 };
	static u8 tuner_go[]       = { TUNER_GO, 0x01};

	mt352_write(fe, clock_config,   sizeof(clock_config));
	udelay(200);
	mt352_write(fe, reset,          sizeof(reset));
	mt352_write(fe, adc_ctl_1_cfg,  sizeof(adc_ctl_1_cfg));
	mt352_write(fe, agc_cfg,        sizeof(agc_cfg));
	mt352_write(fe, input_freq_cfg, sizeof(input_freq_cfg));
	mt352_write(fe, rs_err_cfg,     sizeof(rs_err_cfg));
	mt352_write(fe, capt_range_cfg, sizeof(capt_range_cfg));
	mt352_write(fe, trl_nom_cfg,    sizeof(trl_nom_cfg));
	mt352_write(fe, tps_given_cfg,  sizeof(tps_given_cfg));
	mt352_write(fe, tuner_go,       sizeof(tuner_go));
	return 0;
}

static struct mt352_config terratec_xs_mt352_cfg = {
	.demod_address = (0x1e >> 1),
	.no_tuner = 1,
	.if2 = 45600,
	.demod_init = em28xx_mt352_terratec_xs_init,
};

static struct tda10023_config em28xx_tda10023_config = {
	.demod_address = 0x0c,
	.invert = 1,
};

static struct cxd2820r_config em28xx_cxd2820r_config = {
	.i2c_address = (0xd8 >> 1),
	.ts_mode = CXD2820R_TS_SERIAL,
};

static struct tda18271_config em28xx_cxd2820r_tda18271_config = {
	.output_opt = TDA18271_OUTPUT_LT_OFF,
	.gate = TDA18271_GATE_DIGITAL,
};

static const struct tda10071_config em28xx_tda10071_config = {
	.demod_i2c_addr = 0x55, /* (0xaa >> 1) */
	.tuner_i2c_addr = 0x14,
	.i2c_wr_max = 64,
	.ts_mode = TDA10071_TS_SERIAL,
	.spec_inv = 0,
	.xtal = 40444000, /* 40.444 MHz */
	.pll_multiplier = 20,
};

static const struct a8293_config em28xx_a8293_config = {
	.i2c_addr = 0x08, /* (0x10 >> 1) */
};

static struct zl10353_config em28xx_zl10353_no_i2c_gate_dev = {
	.demod_address = (0x1e >> 1),
	.disable_i2c_gate_ctrl = 1,
	.no_tuner = 1,
	.parallel_ts = 1,
};
static struct qt1010_config em28xx_qt1010_config = {
	.i2c_address = 0x62

};

/* ------------------------------------------------------------------ */

static int em28xx_attach_xc3028(u8 addr, struct em28xx *dev)
{
	struct dvb_frontend *fe;
	struct xc2028_config cfg;

	memset(&cfg, 0, sizeof(cfg));
	cfg.i2c_adap  = &dev->i2c_adap;
	cfg.i2c_addr  = addr;

	if (!dev->dvb->fe[0]) {
		em28xx_errdev("/2: dvb frontend not attached. "
				"Can't attach xc3028\n");
		return -EINVAL;
	}

	fe = dvb_attach(xc2028_attach, dev->dvb->fe[0], &cfg);
	if (!fe) {
		em28xx_errdev("/2: xc3028 attach failed\n");
		dvb_frontend_detach(dev->dvb->fe[0]);
		dev->dvb->fe[0] = NULL;
		return -EINVAL;
	}

	em28xx_info("%s/2: xc3028 attached\n", dev->name);

	return 0;
}

/* ------------------------------------------------------------------ */

static int em28xx_register_dvb(struct em28xx_dvb *dvb, struct module *module,
			       struct em28xx *dev, struct device *device)
{
	int result;

	mutex_init(&dvb->lock);

	/* register adapter */
	result = dvb_register_adapter(&dvb->adapter, dev->name, module, device,
				      adapter_nr);
	if (result < 0) {
		printk(KERN_WARNING "%s: dvb_register_adapter failed (errno = %d)\n",
		       dev->name, result);
		goto fail_adapter;
	}

	/* Ensure all frontends negotiate bus access */
	dvb->fe[0]->ops.ts_bus_ctrl = em28xx_dvb_bus_ctrl;
	if (dvb->fe[1])
		dvb->fe[1]->ops.ts_bus_ctrl = em28xx_dvb_bus_ctrl;

	dvb->adapter.priv = dev;

	/* register frontend */
	result = dvb_register_frontend(&dvb->adapter, dvb->fe[0]);
	if (result < 0) {
		printk(KERN_WARNING "%s: dvb_register_frontend failed (errno = %d)\n",
		       dev->name, result);
		goto fail_frontend0;
	}

	/* register 2nd frontend */
	if (dvb->fe[1]) {
		result = dvb_register_frontend(&dvb->adapter, dvb->fe[1]);
		if (result < 0) {
			printk(KERN_WARNING "%s: 2nd dvb_register_frontend failed (errno = %d)\n",
				dev->name, result);
			goto fail_frontend1;
		}
	}

	/* register demux stuff */
	dvb->demux.dmx.capabilities =
		DMX_TS_FILTERING | DMX_SECTION_FILTERING |
		DMX_MEMORY_BASED_FILTERING;
	dvb->demux.priv       = dvb;
	dvb->demux.filternum  = 256;
	dvb->demux.feednum    = 256;
	dvb->demux.start_feed = em28xx_start_feed;
	dvb->demux.stop_feed  = em28xx_stop_feed;

	result = dvb_dmx_init(&dvb->demux);
	if (result < 0) {
		printk(KERN_WARNING "%s: dvb_dmx_init failed (errno = %d)\n",
		       dev->name, result);
		goto fail_dmx;
	}

	dvb->dmxdev.filternum    = 256;
	dvb->dmxdev.demux        = &dvb->demux.dmx;
	dvb->dmxdev.capabilities = 0;
	result = dvb_dmxdev_init(&dvb->dmxdev, &dvb->adapter);
	if (result < 0) {
		printk(KERN_WARNING "%s: dvb_dmxdev_init failed (errno = %d)\n",
		       dev->name, result);
		goto fail_dmxdev;
	}

	dvb->fe_hw.source = DMX_FRONTEND_0;
	result = dvb->demux.dmx.add_frontend(&dvb->demux.dmx, &dvb->fe_hw);
	if (result < 0) {
		printk(KERN_WARNING "%s: add_frontend failed (DMX_FRONTEND_0, errno = %d)\n",
		       dev->name, result);
		goto fail_fe_hw;
	}

	dvb->fe_mem.source = DMX_MEMORY_FE;
	result = dvb->demux.dmx.add_frontend(&dvb->demux.dmx, &dvb->fe_mem);
	if (result < 0) {
		printk(KERN_WARNING "%s: add_frontend failed (DMX_MEMORY_FE, errno = %d)\n",
		       dev->name, result);
		goto fail_fe_mem;
	}

	result = dvb->demux.dmx.connect_frontend(&dvb->demux.dmx, &dvb->fe_hw);
	if (result < 0) {
		printk(KERN_WARNING "%s: connect_frontend failed (errno = %d)\n",
		       dev->name, result);
		goto fail_fe_conn;
	}

	/* register network adapter */
	dvb_net_init(&dvb->adapter, &dvb->net, &dvb->demux.dmx);
	return 0;

fail_fe_conn:
	dvb->demux.dmx.remove_frontend(&dvb->demux.dmx, &dvb->fe_mem);
fail_fe_mem:
	dvb->demux.dmx.remove_frontend(&dvb->demux.dmx, &dvb->fe_hw);
fail_fe_hw:
	dvb_dmxdev_release(&dvb->dmxdev);
fail_dmxdev:
	dvb_dmx_release(&dvb->demux);
fail_dmx:
	if (dvb->fe[1])
		dvb_unregister_frontend(dvb->fe[1]);
	dvb_unregister_frontend(dvb->fe[0]);
fail_frontend1:
	if (dvb->fe[1])
		dvb_frontend_detach(dvb->fe[1]);
fail_frontend0:
	dvb_frontend_detach(dvb->fe[0]);
	dvb_unregister_adapter(&dvb->adapter);
fail_adapter:
	return result;
}

static void em28xx_unregister_dvb(struct em28xx_dvb *dvb)
{
	dvb_net_release(&dvb->net);
	dvb->demux.dmx.remove_frontend(&dvb->demux.dmx, &dvb->fe_mem);
	dvb->demux.dmx.remove_frontend(&dvb->demux.dmx, &dvb->fe_hw);
	dvb_dmxdev_release(&dvb->dmxdev);
	dvb_dmx_release(&dvb->demux);
	if (dvb->fe[1])
		dvb_unregister_frontend(dvb->fe[1]);
	dvb_unregister_frontend(dvb->fe[0]);
	if (dvb->fe[1] && !dvb->dont_attach_fe1)
		dvb_frontend_detach(dvb->fe[1]);
	dvb_frontend_detach(dvb->fe[0]);
	dvb_unregister_adapter(&dvb->adapter);
}

static int em28xx_dvb_init(struct em28xx *dev)
{
	int result = 0, mfe_shared = 0;
	struct em28xx_dvb *dvb;

	if (!dev->board.has_dvb) {
		/* This device does not support the extension */
		printk(KERN_INFO "em28xx_dvb: This device does not support the extension\n");
		return 0;
	}

	dvb = kzalloc(sizeof(struct em28xx_dvb), GFP_KERNEL);

	if (dvb == NULL) {
		em28xx_info("em28xx_dvb: memory allocation failed\n");
		return -ENOMEM;
	}
	dev->dvb = dvb;
	dvb->fe[0] = dvb->fe[1] = NULL;

	mutex_lock(&dev->lock);
	em28xx_set_mode(dev, EM28XX_DIGITAL_MODE);
	/* init frontend */
	switch (dev->model) {
	case EM2874_BOARD_LEADERSHIP_ISDBT:
		dvb->fe[0] = dvb_attach(s921_attach,
				&sharp_isdbt, &dev->i2c_adap);

		if (!dvb->fe[0]) {
			result = -EINVAL;
			goto out_free;
		}

		break;
	case EM2883_BOARD_HAUPPAUGE_WINTV_HVR_850:
	case EM2883_BOARD_HAUPPAUGE_WINTV_HVR_950:
	case EM2880_BOARD_PINNACLE_PCTV_HD_PRO:
	case EM2880_BOARD_AMD_ATI_TV_WONDER_HD_600:
		dvb->fe[0] = dvb_attach(lgdt330x_attach,
					   &em2880_lgdt3303_dev,
					   &dev->i2c_adap);
		if (em28xx_attach_xc3028(0x61, dev) < 0) {
			result = -EINVAL;
			goto out_free;
		}
		break;
	case EM2880_BOARD_KWORLD_DVB_310U:
		dvb->fe[0] = dvb_attach(zl10353_attach,
					   &em28xx_zl10353_with_xc3028,
					   &dev->i2c_adap);
		if (em28xx_attach_xc3028(0x61, dev) < 0) {
			result = -EINVAL;
			goto out_free;
		}
		break;
	case EM2880_BOARD_HAUPPAUGE_WINTV_HVR_900:
	case EM2882_BOARD_TERRATEC_HYBRID_XS:
	case EM2880_BOARD_EMPIRE_DUAL_TV:
		dvb->fe[0] = dvb_attach(zl10353_attach,
					   &em28xx_zl10353_xc3028_no_i2c_gate,
					   &dev->i2c_adap);
		if (em28xx_attach_xc3028(0x61, dev) < 0) {
			result = -EINVAL;
			goto out_free;
		}
		break;
	case EM2880_BOARD_TERRATEC_HYBRID_XS:
	case EM2880_BOARD_TERRATEC_HYBRID_XS_FR:
	case EM2881_BOARD_PINNACLE_HYBRID_PRO:
	case EM2882_BOARD_DIKOM_DK300:
	case EM2882_BOARD_KWORLD_VS_DVBT:
		dvb->fe[0] = dvb_attach(zl10353_attach,
					   &em28xx_zl10353_xc3028_no_i2c_gate,
					   &dev->i2c_adap);
		if (dvb->fe[0] == NULL) {
			/* This board could have either a zl10353 or a mt352.
			   If the chip id isn't for zl10353, try mt352 */
			dvb->fe[0] = dvb_attach(mt352_attach,
						   &terratec_xs_mt352_cfg,
						   &dev->i2c_adap);
		}

		if (em28xx_attach_xc3028(0x61, dev) < 0) {
			result = -EINVAL;
			goto out_free;
		}
		break;
	case EM2870_BOARD_KWORLD_355U:
		dvb->fe[0] = dvb_attach(zl10353_attach,
					   &em28xx_zl10353_no_i2c_gate_dev,
					   &dev->i2c_adap);
		if (dvb->fe[0] != NULL)
			dvb_attach(qt1010_attach, dvb->fe[0],
				   &dev->i2c_adap, &em28xx_qt1010_config);
		break;
	case EM2883_BOARD_KWORLD_HYBRID_330U:
	case EM2882_BOARD_EVGA_INDTUBE:
		dvb->fe[0] = dvb_attach(s5h1409_attach,
					   &em28xx_s5h1409_with_xc3028,
					   &dev->i2c_adap);
		if (em28xx_attach_xc3028(0x61, dev) < 0) {
			result = -EINVAL;
			goto out_free;
		}
		break;
	case EM2882_BOARD_KWORLD_ATSC_315U:
		dvb->fe[0] = dvb_attach(lgdt330x_attach,
					   &em2880_lgdt3303_dev,
					   &dev->i2c_adap);
		if (dvb->fe[0] != NULL) {
			if (!dvb_attach(simple_tuner_attach, dvb->fe[0],
				&dev->i2c_adap, 0x61, TUNER_THOMSON_DTT761X)) {
				result = -EINVAL;
				goto out_free;
			}
		}
		break;
	case EM2880_BOARD_HAUPPAUGE_WINTV_HVR_900_R2:
	case EM2882_BOARD_PINNACLE_HYBRID_PRO_330E:
		dvb->fe[0] = dvb_attach(drxd_attach, &em28xx_drxd, NULL,
					   &dev->i2c_adap, &dev->udev->dev);
		if (em28xx_attach_xc3028(0x61, dev) < 0) {
			result = -EINVAL;
			goto out_free;
		}
		break;
	case EM2870_BOARD_REDDO_DVB_C_USB_BOX:
		/* Philips CU1216L NIM (Philips TDA10023 + Infineon TUA6034) */
		dvb->fe[0] = dvb_attach(tda10023_attach,
			&em28xx_tda10023_config,
			&dev->i2c_adap, 0x48);
		if (dvb->fe[0]) {
			if (!dvb_attach(simple_tuner_attach, dvb->fe[0],
				&dev->i2c_adap, 0x60, TUNER_PHILIPS_CU1216L)) {
				result = -EINVAL;
				goto out_free;
			}
		}
		break;
	case EM2870_BOARD_KWORLD_A340:
		dvb->fe[0] = dvb_attach(lgdt3305_attach,
					   &em2870_lgdt3304_dev,
					   &dev->i2c_adap);
		if (dvb->fe[0] != NULL)
			dvb_attach(tda18271_attach, dvb->fe[0], 0x60,
				   &dev->i2c_adap, &kworld_a340_config);
		break;
	case EM28174_BOARD_PCTV_290E:
		/* set default GPIO0 for LNA, used if GPIOLIB is undefined */
		dvb->lna_gpio = CXD2820R_GPIO_E | CXD2820R_GPIO_O |
				CXD2820R_GPIO_L;
		dvb->fe[0] = dvb_attach(cxd2820r_attach,
					&em28xx_cxd2820r_config,
					&dev->i2c_adap,
					&dvb->lna_gpio);
		if (dvb->fe[0]) {
			/* FE 0 attach tuner */
			if (!dvb_attach(tda18271_attach,
					dvb->fe[0],
					0x60,
					&dev->i2c_adap,
					&em28xx_cxd2820r_tda18271_config)) {

				dvb_frontend_detach(dvb->fe[0]);
				result = -EINVAL;
				goto out_free;
			}

#ifdef CONFIG_GPIOLIB
			/* enable LNA for DVB-T, DVB-T2 and DVB-C */
			result = gpio_request_one(dvb->lna_gpio,
					GPIOF_OUT_INIT_LOW, NULL);
			if (result)
				em28xx_errdev("gpio request failed %d\n",
						result);
			else
				gpio_free(dvb->lna_gpio);

			result = 0; /* continue even set LNA fails */
#endif
			dvb->fe[0]->ops.set_lna = em28xx_pctv_290e_set_lna;
		}

		break;
	case EM2884_BOARD_HAUPPAUGE_WINTV_HVR_930C:
	{
		struct xc5000_config cfg;
		hauppauge_hvr930c_init(dev);

		dvb->fe[0] = dvb_attach(drxk_attach,
					&hauppauge_930c_drxk, &dev->i2c_adap);
		if (!dvb->fe[0]) {
			result = -EINVAL;
			goto out_free;
		}
		/* FIXME: do we need a pll semaphore? */
		dvb->fe[0]->sec_priv = dvb;
		sema_init(&dvb->pll_mutex, 1);
		dvb->gate_ctrl = dvb->fe[0]->ops.i2c_gate_ctrl;
		dvb->fe[0]->ops.i2c_gate_ctrl = drxk_gate_ctrl;

		/* Attach xc5000 */
		memset(&cfg, 0, sizeof(cfg));
		cfg.i2c_address  = 0x61;
		cfg.if_khz = 4000;

		if (dvb->fe[0]->ops.i2c_gate_ctrl)
			dvb->fe[0]->ops.i2c_gate_ctrl(dvb->fe[0], 1);
		if (!dvb_attach(xc5000_attach, dvb->fe[0], &dev->i2c_adap,
				&cfg)) {
			result = -EINVAL;
			goto out_free;
		}
		if (dvb->fe[0]->ops.i2c_gate_ctrl)
			dvb->fe[0]->ops.i2c_gate_ctrl(dvb->fe[0], 0);

		break;
	}
	case EM2884_BOARD_TERRATEC_H5:
		terratec_h5_init(dev);

		dvb->fe[0] = dvb_attach(drxk_attach, &terratec_h5_drxk, &dev->i2c_adap);
		if (!dvb->fe[0]) {
			result = -EINVAL;
			goto out_free;
		}
		/* FIXME: do we need a pll semaphore? */
		dvb->fe[0]->sec_priv = dvb;
		sema_init(&dvb->pll_mutex, 1);
		dvb->gate_ctrl = dvb->fe[0]->ops.i2c_gate_ctrl;
		dvb->fe[0]->ops.i2c_gate_ctrl = drxk_gate_ctrl;

		/* Attach tda18271 to DVB-C frontend */
		if (dvb->fe[0]->ops.i2c_gate_ctrl)
			dvb->fe[0]->ops.i2c_gate_ctrl(dvb->fe[0], 1);
		if (!dvb_attach(tda18271c2dd_attach, dvb->fe[0], &dev->i2c_adap, 0x60)) {
			result = -EINVAL;
			goto out_free;
		}
		if (dvb->fe[0]->ops.i2c_gate_ctrl)
			dvb->fe[0]->ops.i2c_gate_ctrl(dvb->fe[0], 0);

		break;
	case EM28174_BOARD_PCTV_460E:
		/* attach demod */
		dvb->fe[0] = dvb_attach(tda10071_attach,
			&em28xx_tda10071_config, &dev->i2c_adap);

		/* attach SEC */
		if (dvb->fe[0])
			dvb_attach(a8293_attach, dvb->fe[0], &dev->i2c_adap,
				&em28xx_a8293_config);
		break;
	case EM2874_BOARD_MAXMEDIA_UB425_TC:
		/* attach demodulator */
		dvb->fe[0] = dvb_attach(drxk_attach, &maxmedia_ub425_tc_drxk,
				&dev->i2c_adap);

		if (dvb->fe[0]) {
			/* disable I2C-gate */
			dvb->fe[0]->ops.i2c_gate_ctrl = NULL;

			/* attach tuner */
			if (!dvb_attach(tda18271c2dd_attach, dvb->fe[0],
					&dev->i2c_adap, 0x60)) {
				dvb_frontend_detach(dvb->fe[0]);
				result = -EINVAL;
				goto out_free;
			}
		}

		/* TODO: we need drx-3913k firmware in order to support DVB-T */
		em28xx_info("MaxMedia UB425-TC: only DVB-C supported by that " \
				"driver version\n");

		break;
	case EM2884_BOARD_PCTV_510E:
	case EM2884_BOARD_PCTV_520E:
		pctv_520e_init(dev);

		/* attach demodulator */
		dvb->fe[0] = dvb_attach(drxk_attach, &pctv_520e_drxk,
				&dev->i2c_adap);

		if (dvb->fe[0]) {
			/* attach tuner */
			if (!dvb_attach(tda18271_attach, dvb->fe[0], 0x60,
					&dev->i2c_adap,
					&em28xx_cxd2820r_tda18271_config)) {
				dvb_frontend_detach(dvb->fe[0]);
				result = -EINVAL;
				goto out_free;
			}
		}
		break;
	case EM2884_BOARD_CINERGY_HTC_STICK:
		terratec_htc_stick_init(dev);

		/* attach demodulator */
		dvb->fe[0] = dvb_attach(drxk_attach, &terratec_htc_stick_drxk,
					&dev->i2c_adap);
		if (!dvb->fe[0]) {
			result = -EINVAL;
			goto out_free;
		}

		/* Attach the demodulator. */
		if (!dvb_attach(tda18271_attach, dvb->fe[0], 0x60,
				&dev->i2c_adap,
				&em28xx_cxd2820r_tda18271_config)) {
			result = -EINVAL;
			goto out_free;
		}
		break;
	case EM2884_BOARD_TERRATEC_HTC_USB_XS:
		terratec_htc_usb_xs_init(dev);

		/* attach demodulator */
		dvb->fe[0] = dvb_attach(drxk_attach, &terratec_htc_stick_drxk,
					&dev->i2c_adap);
		if (!dvb->fe[0]) {
			result = -EINVAL;
			goto out_free;
		}

		/* Attach the demodulator. */
		if (!dvb_attach(tda18271_attach, dvb->fe[0], 0x60,
				&dev->i2c_adap,
				&em28xx_cxd2820r_tda18271_config)) {
			result = -EINVAL;
			goto out_free;
		}
		break;
	default:
		em28xx_errdev("/2: The frontend of your DVB/ATSC card"
				" isn't supported yet\n");
		break;
	}
	if (NULL == dvb->fe[0]) {
		em28xx_errdev("/2: frontend initialization failed\n");
		result = -EINVAL;
		goto out_free;
	}
	/* define general-purpose callback pointer */
	dvb->fe[0]->callback = em28xx_tuner_callback;
	if (dvb->fe[1])
		dvb->fe[1]->callback = em28xx_tuner_callback;

	/* register everything */
	result = em28xx_register_dvb(dvb, THIS_MODULE, dev, &dev->udev->dev);

	if (result < 0)
		goto out_free;

	/* MFE lock */
	dvb->adapter.mfe_shared = mfe_shared;

	em28xx_info("Successfully loaded em28xx-dvb\n");
ret:
	em28xx_set_mode(dev, EM28XX_SUSPEND);
	mutex_unlock(&dev->lock);
	return result;

out_free:
	kfree(dvb);
	dev->dvb = NULL;
	goto ret;
}

static inline void prevent_sleep(struct dvb_frontend_ops *ops)
{
	ops->set_voltage = NULL;
	ops->sleep = NULL;
	ops->tuner_ops.sleep = NULL;
}

static int em28xx_dvb_fini(struct em28xx *dev)
{
	if (!dev->board.has_dvb) {
		/* This device does not support the extension */
		return 0;
	}

	if (dev->dvb) {
		struct em28xx_dvb *dvb = dev->dvb;

		if (dev->state & DEV_DISCONNECTED) {
			/* We cannot tell the device to sleep
			 * once it has been unplugged. */
			if (dvb->fe[0])
				prevent_sleep(&dvb->fe[0]->ops);
			if (dvb->fe[1])
				prevent_sleep(&dvb->fe[1]->ops);
		}

		em28xx_unregister_dvb(dvb);
		kfree(dvb);
		dev->dvb = NULL;
	}

	return 0;
}

static struct em28xx_ops dvb_ops = {
	.id   = EM28XX_DVB,
	.name = "Em28xx dvb Extension",
	.init = em28xx_dvb_init,
	.fini = em28xx_dvb_fini,
};

static int __init em28xx_dvb_register(void)
{
	return em28xx_register_extension(&dvb_ops);
}

static void __exit em28xx_dvb_unregister(void)
{
	em28xx_unregister_extension(&dvb_ops);
}

module_init(em28xx_dvb_register);
module_exit(em28xx_dvb_unregister);