drivers/media/tuners/fc0012.c - kernel/msm-4.9 - Gitiles

 /*
  * Fitipower FC0012 tuner driver
  *
  * Copyright (C) 2012 Hans-Frieder Vogt <hfvogt@gmx.net>
  *
  * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
  */

 #include "fc0012.h"
 #include "fc0012-priv.h"

 static int fc0012_writereg(struct fc0012_priv *priv, u8 reg, u8 val)
 {
 	u8 buf[2] = {reg, val};
 	struct i2c_msg msg = {
 		.addr = priv->addr, .flags = 0, .buf = buf, .len = 2
 	};

 	if (i2c_transfer(priv->i2c, &msg, 1) != 1) {
 		err("I2C write reg failed, reg: %02x, val: %02x", reg, val);
 		return -EREMOTEIO;
 	}
 	return 0;
 }

 static int fc0012_readreg(struct fc0012_priv *priv, u8 reg, u8 *val)
 {
 	struct i2c_msg msg[2] = {
 		{ .addr = priv->addr, .flags = 0, .buf = &reg, .len = 1 },
 		{ .addr = priv->addr, .flags = I2C_M_RD, .buf = val, .len = 1 },
 	};

 	if (i2c_transfer(priv->i2c, msg, 2) != 2) {
 		err("I2C read reg failed, reg: %02x", reg);
 		return -EREMOTEIO;
 	}
 	return 0;
 }

 static int fc0012_release(struct dvb_frontend *fe)
 {
 	kfree(fe->tuner_priv);
 	fe->tuner_priv = NULL;
 	return 0;
 }

 static int fc0012_init(struct dvb_frontend *fe)
 {
 	struct fc0012_priv *priv = fe->tuner_priv;
 	int i, ret = 0;
 	unsigned char reg[] = {
 		0x00,	/* dummy reg. 0 */
 		0x05,	/* reg. 0x01 */
 		0x10,	/* reg. 0x02 */
 		0x00,	/* reg. 0x03 */
 		0x00,	/* reg. 0x04 */
 		0x0f,	/* reg. 0x05: may also be 0x0a */
 		0x00,	/* reg. 0x06: divider 2, VCO slow */
 		0x00,	/* reg. 0x07: may also be 0x0f */
 		0xff,	/* reg. 0x08: AGC Clock divide by 256, AGC gain 1/256,
 			   Loop Bw 1/8 */
 		0x6e,	/* reg. 0x09: Disable LoopThrough, Enable LoopThrough: 0x6f */
 		0xb8,	/* reg. 0x0a: Disable LO Test Buffer */
 		0x82,	/* reg. 0x0b: Output Clock is same as clock frequency,
 			   may also be 0x83 */
 		0xfc,	/* reg. 0x0c: depending on AGC Up-Down mode, may need 0xf8 */
 		0x02,	/* reg. 0x0d: AGC Not Forcing & LNA Forcing, 0x02 for DVB-T */
 		0x00,	/* reg. 0x0e */
 		0x00,	/* reg. 0x0f */
 		0x00,	/* reg. 0x10: may also be 0x0d */
 		0x00,	/* reg. 0x11 */
 		0x1f,	/* reg. 0x12: Set to maximum gain */
 		0x08,	/* reg. 0x13: Set to Middle Gain: 0x08,
 			   Low Gain: 0x00, High Gain: 0x10, enable IX2: 0x80 */
 		0x00,	/* reg. 0x14 */
 		0x04,	/* reg. 0x15: Enable LNA COMPS */
 	};

 	switch (priv->xtal_freq) {
 	case FC_XTAL_27_MHZ:
 	case FC_XTAL_28_8_MHZ:
 		reg[0x07] |= 0x20;
 		break;
 	case FC_XTAL_36_MHZ:
 	default:
 		break;
 	}

 	if (priv->dual_master)
 		reg[0x0c] |= 0x02;

 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */

 	for (i = 1; i < sizeof(reg); i++) {
 		ret = fc0012_writereg(priv, i, reg[i]);
 		if (ret)
 			break;
 	}

 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */

 	if (ret)
 		err("fc0012_writereg failed: %d", ret);

 	return ret;
 }

 static int fc0012_sleep(struct dvb_frontend *fe)
 {
 	/* nothing to do here */
 	return 0;
 }

 static int fc0012_set_params(struct dvb_frontend *fe)
 {
 	struct fc0012_priv *priv = fe->tuner_priv;
 	int i, ret = 0;
 	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
 	u32 freq = p->frequency / 1000;
 	u32 delsys = p->delivery_system;
 	unsigned char reg[7], am, pm, multi, tmp;
 	unsigned long f_vco;
 	unsigned short xtal_freq_khz_2, xin, xdiv;
 	int vco_select = false;

 	if (fe->callback) {
 		ret = fe->callback(priv->i2c, DVB_FRONTEND_COMPONENT_TUNER,
 			FC_FE_CALLBACK_VHF_ENABLE, (freq > 300000 ? 0 : 1));
 		if (ret)
 			goto exit;
 	}

 	switch (priv->xtal_freq) {
 	case FC_XTAL_27_MHZ:
 		xtal_freq_khz_2 = 27000 / 2;
 		break;
 	case FC_XTAL_36_MHZ:
 		xtal_freq_khz_2 = 36000 / 2;
 		break;
 	case FC_XTAL_28_8_MHZ:
 	default:
 		xtal_freq_khz_2 = 28800 / 2;
 		break;
 	}

 	/* select frequency divider and the frequency of VCO */
 	if (freq < 37084) {		/* freq * 96 < 3560000 */
 		multi = 96;
 		reg[5] = 0x82;
 		reg[6] = 0x00;
 	} else if (freq < 55625) {	/* freq * 64 < 3560000 */
 		multi = 64;
 		reg[5] = 0x82;
 		reg[6] = 0x02;
 	} else if (freq < 74167) {	/* freq * 48 < 3560000 */
 		multi = 48;
 		reg[5] = 0x42;
 		reg[6] = 0x00;
 	} else if (freq < 111250) {	/* freq * 32 < 3560000 */
 		multi = 32;
 		reg[5] = 0x42;
 		reg[6] = 0x02;
 	} else if (freq < 148334) {	/* freq * 24 < 3560000 */
 		multi = 24;
 		reg[5] = 0x22;
 		reg[6] = 0x00;
 	} else if (freq < 222500) {	/* freq * 16 < 3560000 */
 		multi = 16;
 		reg[5] = 0x22;
 		reg[6] = 0x02;
 	} else if (freq < 296667) {	/* freq * 12 < 3560000 */
 		multi = 12;
 		reg[5] = 0x12;
 		reg[6] = 0x00;
 	} else if (freq < 445000) {	/* freq * 8 < 3560000 */
 		multi = 8;
 		reg[5] = 0x12;
 		reg[6] = 0x02;
 	} else if (freq < 593334) {	/* freq * 6 < 3560000 */
 		multi = 6;
 		reg[5] = 0x0a;
 		reg[6] = 0x00;
 	} else {
 		multi = 4;
 		reg[5] = 0x0a;
 		reg[6] = 0x02;
 	}

 	f_vco = freq * multi;

 	if (f_vco >= 3060000) {
 		reg[6] |= 0x08;
 		vco_select = true;
 	}

 	if (freq >= 45000) {
 		/* From divided value (XDIV) determined the FA and FP value */
 		xdiv = (unsigned short)(f_vco / xtal_freq_khz_2);
 		if ((f_vco - xdiv * xtal_freq_khz_2) >= (xtal_freq_khz_2 / 2))
 			xdiv++;

 		pm = (unsigned char)(xdiv / 8);
 		am = (unsigned char)(xdiv - (8 * pm));

 		if (am < 2) {
 			reg[1] = am + 8;
 			reg[2] = pm - 1;
 		} else {
 			reg[1] = am;
 			reg[2] = pm;
 		}
 	} else {
 		/* fix for frequency less than 45 MHz */
 		reg[1] = 0x06;
 		reg[2] = 0x11;
 	}

 	/* fix clock out */
 	reg[6] |= 0x20;

 	/* From VCO frequency determines the XIN ( fractional part of Delta
 	   Sigma PLL) and divided value (XDIV) */
 	xin = (unsigned short)(f_vco - (f_vco / xtal_freq_khz_2) * xtal_freq_khz_2);
 	xin = (xin << 15) / xtal_freq_khz_2;
 	if (xin >= 16384)
 		xin += 32768;

 	reg[3] = xin >> 8;	/* xin with 9 bit resolution */
 	reg[4] = xin & 0xff;

 	if (delsys == SYS_DVBT) {
 		reg[6] &= 0x3f;	/* bits 6 and 7 describe the bandwidth */
 		switch (p->bandwidth_hz) {
 		case 6000000:
 			reg[6] |= 0x80;
 			break;
 		case 7000000:
 			reg[6] |= 0x40;
 			break;
 		case 8000000:
 		default:
 			break;
 		}
 	} else {
 		err("%s: modulation type not supported!", __func__);
 		return -EINVAL;
 	}

 	/* modified for Realtek demod */
 	reg[5] |= 0x07;

 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */

 	for (i = 1; i <= 6; i++) {
 		ret = fc0012_writereg(priv, i, reg[i]);
 		if (ret)
 			goto exit;
 	}

 	/* VCO Calibration */
 	ret = fc0012_writereg(priv, 0x0e, 0x80);
 	if (!ret)
 		ret = fc0012_writereg(priv, 0x0e, 0x00);

 	/* VCO Re-Calibration if needed */
 	if (!ret)
 		ret = fc0012_writereg(priv, 0x0e, 0x00);

 	if (!ret) {
 		msleep(10);
 		ret = fc0012_readreg(priv, 0x0e, &tmp);
 	}
 	if (ret)
 		goto exit;

 	/* vco selection */
 	tmp &= 0x3f;

 	if (vco_select) {
 		if (tmp > 0x3c) {
 			reg[6] &= ~0x08;
 			ret = fc0012_writereg(priv, 0x06, reg[6]);
 			if (!ret)
 				ret = fc0012_writereg(priv, 0x0e, 0x80);
 			if (!ret)
 				ret = fc0012_writereg(priv, 0x0e, 0x00);
 		}
 	} else {
 		if (tmp < 0x02) {
 			reg[6] |= 0x08;
 			ret = fc0012_writereg(priv, 0x06, reg[6]);
 			if (!ret)
 				ret = fc0012_writereg(priv, 0x0e, 0x80);
 			if (!ret)
 				ret = fc0012_writereg(priv, 0x0e, 0x00);
 		}
 	}

 	priv->frequency = p->frequency;
 	priv->bandwidth = p->bandwidth_hz;

 exit:
 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */
 	if (ret)
 		warn("%s: failed: %d", __func__, ret);
 	return ret;
 }

 static int fc0012_get_frequency(struct dvb_frontend *fe, u32 *frequency)
 {
 	struct fc0012_priv *priv = fe->tuner_priv;
 	*frequency = priv->frequency;
 	return 0;
 }

 static int fc0012_get_if_frequency(struct dvb_frontend *fe, u32 *frequency)
 {
 	/* CHECK: always ? */
 	*frequency = 0;
 	return 0;
 }

 static int fc0012_get_bandwidth(struct dvb_frontend *fe, u32 *bandwidth)
 {
 	struct fc0012_priv *priv = fe->tuner_priv;
 	*bandwidth = priv->bandwidth;
 	return 0;
 }

 #define INPUT_ADC_LEVEL	-8

 static int fc0012_get_rf_strength(struct dvb_frontend *fe, u16 *strength)
 {
 	struct fc0012_priv *priv = fe->tuner_priv;
 	int ret;
 	unsigned char tmp;
 	int int_temp, lna_gain, int_lna, tot_agc_gain, power;
 	const int fc0012_lna_gain_table[] = {
 		/* low gain */
 		-63, -58, -99, -73,
 		-63, -65, -54, -60,
 		/* middle gain */
 		 71,  70,  68,  67,
 		 65,  63,  61,  58,
 		/* high gain */
 		197, 191, 188, 186,
 		184, 182, 181, 179,
 	};

 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */

 	ret = fc0012_writereg(priv, 0x12, 0x00);
 	if (ret)
 		goto err;

 	ret = fc0012_readreg(priv, 0x12, &tmp);
 	if (ret)
 		goto err;
 	int_temp = tmp;

 	ret = fc0012_readreg(priv, 0x13, &tmp);
 	if (ret)
 		goto err;
 	lna_gain = tmp & 0x1f;

 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */

 	if (lna_gain < ARRAY_SIZE(fc0012_lna_gain_table)) {
 		int_lna = fc0012_lna_gain_table[lna_gain];
 		tot_agc_gain = (abs((int_temp >> 5) - 7) - 2 +
 				(int_temp & 0x1f)) * 2;
 		power = INPUT_ADC_LEVEL - tot_agc_gain - int_lna / 10;

 		if (power >= 45)
 			*strength = 255;	/* 100% */
 		else if (power < -95)
 			*strength = 0;
 		else
 			*strength = (power + 95) * 255 / 140;

 		*strength |= *strength << 8;
 	} else {
 		ret = -1;
 	}

 	goto exit;

 err:
 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */
 exit:
 	if (ret)
 		warn("%s: failed: %d", __func__, ret);
 	return ret;
 }

 static const struct dvb_tuner_ops fc0012_tuner_ops = {
 	.info = {
 		.name           = "Fitipower FC0012",

 		.frequency_min  = 37000000,	/* estimate */
 		.frequency_max  = 862000000,	/* estimate */
 		.frequency_step = 0,
 	},

 	.release	= fc0012_release,

 	.init		= fc0012_init,
 	.sleep		= fc0012_sleep,

 	.set_params	= fc0012_set_params,

 	.get_frequency	= fc0012_get_frequency,
 	.get_if_frequency = fc0012_get_if_frequency,
 	.get_bandwidth	= fc0012_get_bandwidth,

 	.get_rf_strength = fc0012_get_rf_strength,
 };

 struct dvb_frontend *fc0012_attach(struct dvb_frontend *fe,
 	struct i2c_adapter *i2c, u8 i2c_address, int dual_master,
 	enum fc001x_xtal_freq xtal_freq)
 {
 	struct fc0012_priv *priv = NULL;

 	priv = kzalloc(sizeof(struct fc0012_priv), GFP_KERNEL);
 	if (priv == NULL)
 		return NULL;

 	priv->i2c = i2c;
 	priv->dual_master = dual_master;
 	priv->addr = i2c_address;
 	priv->xtal_freq = xtal_freq;

 	info("Fitipower FC0012 successfully attached.");

 	fe->tuner_priv = priv;

 	memcpy(&fe->ops.tuner_ops, &fc0012_tuner_ops,
 		sizeof(struct dvb_tuner_ops));

 	return fe;
 }
 EXPORT_SYMBOL(fc0012_attach);

 MODULE_DESCRIPTION("Fitipower FC0012 silicon tuner driver");
 MODULE_AUTHOR("Hans-Frieder Vogt <hfvogt@gmx.net>");
 MODULE_LICENSE("GPL");
 MODULE_VERSION("0.6");
	/*
	* Fitipower FC0012 tuner driver
	*
	* Copyright (C) 2012 Hans-Frieder Vogt <hfvogt@gmx.net>
	*
	* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
	*/

	#include "fc0012.h"
	#include "fc0012-priv.h"

	static int fc0012_writereg(struct fc0012_priv *priv, u8 reg, u8 val)
	{
	u8 buf[2] = {reg, val};
	struct i2c_msg msg = {
	.addr = priv->addr, .flags = 0, .buf = buf, .len = 2
	};

	if (i2c_transfer(priv->i2c, &msg, 1) != 1) {
	err("I2C write reg failed, reg: %02x, val: %02x", reg, val);
	return -EREMOTEIO;
	}
	return 0;
	}

	static int fc0012_readreg(struct fc0012_priv priv, u8 reg, u8 val)
	{
	struct i2c_msg msg[2] = {
	{ .addr = priv->addr, .flags = 0, .buf = &reg, .len = 1 },
	{ .addr = priv->addr, .flags = I2C_M_RD, .buf = val, .len = 1 },
	};

	if (i2c_transfer(priv->i2c, msg, 2) != 2) {
	err("I2C read reg failed, reg: %02x", reg);
	return -EREMOTEIO;
	}
	return 0;
	}

	static int fc0012_release(struct dvb_frontend *fe)
	{
	kfree(fe->tuner_priv);
	fe->tuner_priv = NULL;
	return 0;
	}

	static int fc0012_init(struct dvb_frontend *fe)
	{
	struct fc0012_priv *priv = fe->tuner_priv;
	int i, ret = 0;
	unsigned char reg[] = {
	0x00, /* dummy reg. 0 */
	0x05, /* reg. 0x01 */
	0x10, /* reg. 0x02 */
	0x00, /* reg. 0x03 */
	0x00, /* reg. 0x04 */
	0x0f, /* reg. 0x05: may also be 0x0a */
	0x00, /* reg. 0x06: divider 2, VCO slow */
	0x00, /* reg. 0x07: may also be 0x0f */
	0xff, /* reg. 0x08: AGC Clock divide by 256, AGC gain 1/256,
	Loop Bw 1/8 */
	0x6e, /* reg. 0x09: Disable LoopThrough, Enable LoopThrough: 0x6f */
	0xb8, /* reg. 0x0a: Disable LO Test Buffer */
	0x82, /* reg. 0x0b: Output Clock is same as clock frequency,
	may also be 0x83 */
	0xfc, /* reg. 0x0c: depending on AGC Up-Down mode, may need 0xf8 */
	0x02, /* reg. 0x0d: AGC Not Forcing & LNA Forcing, 0x02 for DVB-T */
	0x00, /* reg. 0x0e */
	0x00, /* reg. 0x0f */
	0x00, /* reg. 0x10: may also be 0x0d */
	0x00, /* reg. 0x11 */
	0x1f, /* reg. 0x12: Set to maximum gain */
	0x08, /* reg. 0x13: Set to Middle Gain: 0x08,
	Low Gain: 0x00, High Gain: 0x10, enable IX2: 0x80 */
	0x00, /* reg. 0x14 */
	0x04, /* reg. 0x15: Enable LNA COMPS */
	};

	switch (priv->xtal_freq) {
	case FC_XTAL_27_MHZ:
	case FC_XTAL_28_8_MHZ:
	reg[0x07] \|= 0x20;
	break;
	case FC_XTAL_36_MHZ:
	default:
	break;
	}

	if (priv->dual_master)
	reg[0x0c] \|= 0x02;

	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */

	for (i = 1; i < sizeof(reg); i++) {
	ret = fc0012_writereg(priv, i, reg[i]);
	if (ret)
	break;
	}

	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */

	if (ret)
	err("fc0012_writereg failed: %d", ret);

	return ret;
	}

	static int fc0012_sleep(struct dvb_frontend *fe)
	{
	/* nothing to do here */
	return 0;
	}

	static int fc0012_set_params(struct dvb_frontend *fe)
	{
	struct fc0012_priv *priv = fe->tuner_priv;
	int i, ret = 0;
	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
	u32 freq = p->frequency / 1000;
	u32 delsys = p->delivery_system;
	unsigned char reg[7], am, pm, multi, tmp;
	unsigned long f_vco;
	unsigned short xtal_freq_khz_2, xin, xdiv;
	int vco_select = false;

	if (fe->callback) {
	ret = fe->callback(priv->i2c, DVB_FRONTEND_COMPONENT_TUNER,
	FC_FE_CALLBACK_VHF_ENABLE, (freq > 300000 ? 0 : 1));
	if (ret)
	goto exit;
	}

	switch (priv->xtal_freq) {
	case FC_XTAL_27_MHZ:
	xtal_freq_khz_2 = 27000 / 2;
	break;
	case FC_XTAL_36_MHZ:
	xtal_freq_khz_2 = 36000 / 2;
	break;
	case FC_XTAL_28_8_MHZ:
	default:
	xtal_freq_khz_2 = 28800 / 2;
	break;
	}

	/* select frequency divider and the frequency of VCO */
	if (freq < 37084) { /* freq * 96 < 3560000 */
	multi = 96;
	reg[5] = 0x82;
	reg[6] = 0x00;
	} else if (freq < 55625) { /* freq * 64 < 3560000 */
	multi = 64;
	reg[5] = 0x82;
	reg[6] = 0x02;
	} else if (freq < 74167) { /* freq * 48 < 3560000 */
	multi = 48;
	reg[5] = 0x42;
	reg[6] = 0x00;
	} else if (freq < 111250) { /* freq * 32 < 3560000 */
	multi = 32;
	reg[5] = 0x42;
	reg[6] = 0x02;
	} else if (freq < 148334) { /* freq * 24 < 3560000 */
	multi = 24;
	reg[5] = 0x22;
	reg[6] = 0x00;
	} else if (freq < 222500) { /* freq * 16 < 3560000 */
	multi = 16;
	reg[5] = 0x22;
	reg[6] = 0x02;
	} else if (freq < 296667) { /* freq * 12 < 3560000 */
	multi = 12;
	reg[5] = 0x12;
	reg[6] = 0x00;
	} else if (freq < 445000) { /* freq * 8 < 3560000 */
	multi = 8;
	reg[5] = 0x12;
	reg[6] = 0x02;
	} else if (freq < 593334) { /* freq * 6 < 3560000 */
	multi = 6;
	reg[5] = 0x0a;
	reg[6] = 0x00;
	} else {
	multi = 4;
	reg[5] = 0x0a;
	reg[6] = 0x02;
	}

	f_vco = freq * multi;

	if (f_vco >= 3060000) {
	reg[6] \|= 0x08;
	vco_select = true;
	}

	if (freq >= 45000) {
	/* From divided value (XDIV) determined the FA and FP value */
	xdiv = (unsigned short)(f_vco / xtal_freq_khz_2);
	if ((f_vco - xdiv * xtal_freq_khz_2) >= (xtal_freq_khz_2 / 2))
	xdiv++;

	pm = (unsigned char)(xdiv / 8);
	am = (unsigned char)(xdiv - (8 * pm));

	if (am < 2) {
	reg[1] = am + 8;
	reg[2] = pm - 1;
	} else {
	reg[1] = am;
	reg[2] = pm;
	}
	} else {
	/* fix for frequency less than 45 MHz */
	reg[1] = 0x06;
	reg[2] = 0x11;
	}

	/* fix clock out */
	reg[6] \|= 0x20;

	/* From VCO frequency determines the XIN ( fractional part of Delta
	Sigma PLL) and divided value (XDIV) */
	xin = (unsigned short)(f_vco - (f_vco / xtal_freq_khz_2) * xtal_freq_khz_2);
	xin = (xin << 15) / xtal_freq_khz_2;
	if (xin >= 16384)
	xin += 32768;

	reg[3] = xin >> 8; /* xin with 9 bit resolution */
	reg[4] = xin & 0xff;

	if (delsys == SYS_DVBT) {
	reg[6] &= 0x3f; /* bits 6 and 7 describe the bandwidth */
	switch (p->bandwidth_hz) {
	case 6000000:
	reg[6] \|= 0x80;
	break;
	case 7000000:
	reg[6] \|= 0x40;
	break;
	case 8000000:
	default:
	break;
	}
	} else {
	err("%s: modulation type not supported!", __func__);
	return -EINVAL;
	}

	/* modified for Realtek demod */
	reg[5] \|= 0x07;

	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */

	for (i = 1; i <= 6; i++) {
	ret = fc0012_writereg(priv, i, reg[i]);
	if (ret)
	goto exit;
	}

	/* VCO Calibration */
	ret = fc0012_writereg(priv, 0x0e, 0x80);
	if (!ret)
	ret = fc0012_writereg(priv, 0x0e, 0x00);

	/* VCO Re-Calibration if needed */
	if (!ret)
	ret = fc0012_writereg(priv, 0x0e, 0x00);

	if (!ret) {
	msleep(10);
	ret = fc0012_readreg(priv, 0x0e, &tmp);
	}
	if (ret)
	goto exit;

	/* vco selection */
	tmp &= 0x3f;

	if (vco_select) {
	if (tmp > 0x3c) {
	reg[6] &= ~0x08;
	ret = fc0012_writereg(priv, 0x06, reg[6]);
	if (!ret)
	ret = fc0012_writereg(priv, 0x0e, 0x80);
	if (!ret)
	ret = fc0012_writereg(priv, 0x0e, 0x00);
	}
	} else {
	if (tmp < 0x02) {
	reg[6] \|= 0x08;
	ret = fc0012_writereg(priv, 0x06, reg[6]);
	if (!ret)
	ret = fc0012_writereg(priv, 0x0e, 0x80);
	if (!ret)
	ret = fc0012_writereg(priv, 0x0e, 0x00);
	}
	}

	priv->frequency = p->frequency;
	priv->bandwidth = p->bandwidth_hz;

	exit:
	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */
	if (ret)
	warn("%s: failed: %d", __func__, ret);
	return ret;
	}

	static int fc0012_get_frequency(struct dvb_frontend fe, u32 frequency)
	{
	struct fc0012_priv *priv = fe->tuner_priv;
	*frequency = priv->frequency;
	return 0;
	}

	static int fc0012_get_if_frequency(struct dvb_frontend fe, u32 frequency)
	{
	/* CHECK: always ? */
	*frequency = 0;
	return 0;
	}

	static int fc0012_get_bandwidth(struct dvb_frontend fe, u32 bandwidth)
	{
	struct fc0012_priv *priv = fe->tuner_priv;
	*bandwidth = priv->bandwidth;
	return 0;
	}

	#define INPUT_ADC_LEVEL -8

	static int fc0012_get_rf_strength(struct dvb_frontend fe, u16 strength)
	{
	struct fc0012_priv *priv = fe->tuner_priv;
	int ret;
	unsigned char tmp;
	int int_temp, lna_gain, int_lna, tot_agc_gain, power;
	const int fc0012_lna_gain_table[] = {
	/* low gain */
	-63, -58, -99, -73,
	-63, -65, -54, -60,
	/* middle gain */
	71, 70, 68, 67,
	65, 63, 61, 58,
	/* high gain */
	197, 191, 188, 186,
	184, 182, 181, 179,
	};

	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */

	ret = fc0012_writereg(priv, 0x12, 0x00);
	if (ret)
	goto err;

	ret = fc0012_readreg(priv, 0x12, &tmp);
	if (ret)
	goto err;
	int_temp = tmp;

	ret = fc0012_readreg(priv, 0x13, &tmp);
	if (ret)
	goto err;
	lna_gain = tmp & 0x1f;

	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */

	if (lna_gain < ARRAY_SIZE(fc0012_lna_gain_table)) {
	int_lna = fc0012_lna_gain_table[lna_gain];
	tot_agc_gain = (abs((int_temp >> 5) - 7) - 2 +
	(int_temp & 0x1f)) * 2;
	power = INPUT_ADC_LEVEL - tot_agc_gain - int_lna / 10;

	if (power >= 45)
	strength = 255; / 100% */
	else if (power < -95)
	*strength = 0;
	else
	strength = (power + 95) 255 / 140;

	strength \|= strength << 8;
	} else {
	ret = -1;
	}

	goto exit;

	err:
	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */
	exit:
	if (ret)
	warn("%s: failed: %d", __func__, ret);
	return ret;
	}

	static const struct dvb_tuner_ops fc0012_tuner_ops = {
	.info = {
	.name = "Fitipower FC0012",

	.frequency_min = 37000000, /* estimate */
	.frequency_max = 862000000, /* estimate */
	.frequency_step = 0,
	},

	.release = fc0012_release,

	.init = fc0012_init,
	.sleep = fc0012_sleep,

	.set_params = fc0012_set_params,

	.get_frequency = fc0012_get_frequency,
	.get_if_frequency = fc0012_get_if_frequency,
	.get_bandwidth = fc0012_get_bandwidth,

	.get_rf_strength = fc0012_get_rf_strength,
	};

	struct dvb_frontend fc0012_attach(struct dvb_frontend fe,
	struct i2c_adapter *i2c, u8 i2c_address, int dual_master,
	enum fc001x_xtal_freq xtal_freq)
	{
	struct fc0012_priv *priv = NULL;

	priv = kzalloc(sizeof(struct fc0012_priv), GFP_KERNEL);
	if (priv == NULL)
	return NULL;

	priv->i2c = i2c;
	priv->dual_master = dual_master;
	priv->addr = i2c_address;
	priv->xtal_freq = xtal_freq;

	info("Fitipower FC0012 successfully attached.");

	fe->tuner_priv = priv;

	memcpy(&fe->ops.tuner_ops, &fc0012_tuner_ops,
	sizeof(struct dvb_tuner_ops));

	return fe;
	}
	EXPORT_SYMBOL(fc0012_attach);

	MODULE_DESCRIPTION("Fitipower FC0012 silicon tuner driver");
	MODULE_AUTHOR("Hans-Frieder Vogt <hfvogt@gmx.net>");
	MODULE_LICENSE("GPL");
	MODULE_VERSION("0.6");