drivers/media/dvb-frontends/zl10036.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Driver for Zarlink zl10036 DVB-S silicon tuner
  *
  * Copyright (C) 2006 Tino Reichardt
  * Copyright (C) 2007-2009 Matthias Schwarzott <zzam@gentoo.de>
  *
  **
  * The data sheet for this tuner can be found at:
  *    http://www.mcmilk.de/projects/dvb-card/datasheets/ZL10036.pdf
  *
  * This one is working: (at my Avermedia DVB-S Pro)
  * - zl10036 (40pin, FTA)
  *
  * A driver for zl10038 should be very similar.
  */

 #include <linux/module.h>
 #include <linux/dvb/frontend.h>
 #include <linux/slab.h>
 #include <linux/types.h>

 #include "zl10036.h"

 static int zl10036_debug;
 #define dprintk(level, args...) \
 	do { if (zl10036_debug & level) printk(KERN_DEBUG "zl10036: " args); \
 	} while (0)

 #define deb_info(args...)  dprintk(0x01, args)
 #define deb_i2c(args...)  dprintk(0x02, args)

 struct zl10036_state {
 	struct i2c_adapter *i2c;
 	const struct zl10036_config *config;
 	u32 frequency;
 	u8 br, bf;
 };


 /* This driver assumes the tuner is driven by a 10.111MHz Cristal */
 #define _XTAL 10111

 /* Some of the possible dividers:
  *   64, (write 0x05 to reg), freq step size   158kHz
  *   10, (write 0x0a to reg), freq step size 1.011kHz (used here)
  *    5, (write 0x09 to reg), freq step size 2.022kHz
  */

 #define _RDIV 10
 #define _RDIV_REG 0x0a
 #define _FR   (_XTAL/_RDIV)

 #define STATUS_POR 0x80 /* Power on Reset */
 #define STATUS_FL  0x40 /* Frequency & Phase Lock */

 /* read/write for zl10036 and zl10038 */

 static int zl10036_read_status_reg(struct zl10036_state *state)
 {
 	u8 status;
 	struct i2c_msg msg[1] = {
 		{ .addr = state->config->tuner_address, .flags = I2C_M_RD,
 		  .buf = &status, .len = sizeof(status) },
 	};

 	if (i2c_transfer(state->i2c, msg, 1) != 1) {
 		printk(KERN_ERR "%s: i2c read failed at addr=%02x\n",
 			__func__, state->config->tuner_address);
 		return -EIO;
 	}

 	deb_i2c("R(status): %02x  [FL=%d]\n", status,
 		(status & STATUS_FL) ? 1 : 0);
 	if (status & STATUS_POR)
 		deb_info("%s: Power-On-Reset bit enabled - need to initialize the tuner\n",
 			 __func__);

 	return status;
 }

 static int zl10036_write(struct zl10036_state *state, u8 buf[], u8 count)
 {
 	struct i2c_msg msg[1] = {
 		{ .addr = state->config->tuner_address, .flags = 0,
 		  .buf = buf, .len = count },
 	};
 	u8 reg = 0;
 	int ret;

 	if (zl10036_debug & 0x02) {
 		/* every 8bit-value satisifes this!
 		 * so only check for debug log */
 		if ((buf[0] & 0x80) == 0x00)
 			reg = 2;
 		else if ((buf[0] & 0xc0) == 0x80)
 			reg = 4;
 		else if ((buf[0] & 0xf0) == 0xc0)
 			reg = 6;
 		else if ((buf[0] & 0xf0) == 0xd0)
 			reg = 8;
 		else if ((buf[0] & 0xf0) == 0xe0)
 			reg = 10;
 		else if ((buf[0] & 0xf0) == 0xf0)
 			reg = 12;

 		deb_i2c("W(%d):", reg);
 		{
 			int i;
 			for (i = 0; i < count; i++)
 				printk(KERN_CONT " %02x", buf[i]);
 			printk(KERN_CONT "\n");
 		}
 	}

 	ret = i2c_transfer(state->i2c, msg, 1);
 	if (ret != 1) {
 		printk(KERN_ERR "%s: i2c error, ret=%d\n", __func__, ret);
 		return -EIO;
 	}

 	return 0;
 }

 static void zl10036_release(struct dvb_frontend *fe)
 {
 	struct zl10036_state *state = fe->tuner_priv;

 	fe->tuner_priv = NULL;
 	kfree(state);
 }

 static int zl10036_sleep(struct dvb_frontend *fe)
 {
 	struct zl10036_state *state = fe->tuner_priv;
 	u8 buf[] = { 0xf0, 0x80 }; /* regs 12/13 */
 	int ret;

 	deb_info("%s\n", __func__);

 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */

 	ret = zl10036_write(state, buf, sizeof(buf));

 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */

 	return ret;
 }

 /*
  * register map of the ZL10036/ZL10038
  *
  * reg[default] content
  *  2[0x00]:   0 | N14 | N13 | N12 | N11 | N10 |  N9 |  N8
  *  3[0x00]:  N7 |  N6 |  N5 |  N4 |  N3 |  N2 |  N1 |  N0
  *  4[0x80]:   1 |   0 | RFG | BA1 | BA0 | BG1 | BG0 | LEN
  *  5[0x00]:  P0 |  C1 |  C0 |  R4 |  R3 |  R2 |  R1 |  R0
  *  6[0xc0]:   1 |   1 |   0 |   0 | RSD |   0 |   0 |   0
  *  7[0x20]:  P1 | BF6 | BF5 | BF4 | BF3 | BF2 | BF1 |   0
  *  8[0xdb]:   1 |   1 |   0 |   1 |   0 |  CC |   1 |   1
  *  9[0x30]: VSD |  V2 |  V1 |  V0 |  S3 |  S2 |  S1 |  S0
  * 10[0xe1]:   1 |   1 |   1 |   0 |   0 | LS2 | LS1 | LS0
  * 11[0xf5]:  WS | WH2 | WH1 | WH0 | WL2 | WL1 | WL0 | WRE
  * 12[0xf0]:   1 |   1 |   1 |   1 |   0 |   0 |   0 |   0
  * 13[0x28]:  PD | BR4 | BR3 | BR2 | BR1 | BR0 | CLR |  TL
  */

 static int zl10036_set_frequency(struct zl10036_state *state, u32 frequency)
 {
 	u8 buf[2];
 	u32 div, foffset;

 	div = (frequency + _FR/2) / _FR;
 	state->frequency = div * _FR;

 	foffset = frequency - state->frequency;

 	buf[0] = (div >> 8) & 0x7f;
 	buf[1] = (div >> 0) & 0xff;

 	deb_info("%s: ftodo=%u fpriv=%u ferr=%d div=%u\n", __func__,
 		frequency, state->frequency, foffset, div);

 	return zl10036_write(state, buf, sizeof(buf));
 }

 static int zl10036_set_bandwidth(struct zl10036_state *state, u32 fbw)
 {
 	/* fbw is measured in kHz */
 	u8 br, bf;
 	int ret;
 	u8 buf_bf[] = {
 		0xc0, 0x00, /*   6/7: rsd=0 bf=0 */
 	};
 	u8 buf_br[] = {
 		0xf0, 0x00, /* 12/13: br=0xa clr=0 tl=0*/
 	};
 	u8 zl10036_rsd_off[] = { 0xc8 }; /* set RSD=1 */

 	/* ensure correct values */
 	if (fbw > 35000)
 		fbw = 35000;
 	if (fbw <  8000)
 		fbw =  8000;

 #define _BR_MAXIMUM (_XTAL/575) /* _XTAL / 575kHz = 17 */

 	/* <= 28,82 MHz */
 	if (fbw <= 28820) {
 		br = _BR_MAXIMUM;
 	} else {
 		/*
 		 *  f(bw)=34,6MHz f(xtal)=10.111MHz
 		 *  br = (10111/34600) * 63 * 1/K = 14;
 		 */
 		br = ((_XTAL * 21 * 1000) / (fbw * 419));
 	}

 	/* ensure correct values */
 	if (br < 4)
 		br = 4;
 	if (br > _BR_MAXIMUM)
 		br = _BR_MAXIMUM;

 	/*
 	 * k = 1.257
 	 * bf = fbw/_XTAL * br * k - 1 */

 	bf = (fbw * br * 1257) / (_XTAL * 1000) - 1;

 	/* ensure correct values */
 	if (bf > 62)
 		bf = 62;

 	buf_bf[1] = (bf << 1) & 0x7e;
 	buf_br[1] = (br << 2) & 0x7c;
 	deb_info("%s: BW=%d br=%u bf=%u\n", __func__, fbw, br, bf);

 	if (br != state->br) {
 		ret = zl10036_write(state, buf_br, sizeof(buf_br));
 		if (ret < 0)
 			return ret;
 	}

 	if (bf != state->bf) {
 		ret = zl10036_write(state, buf_bf, sizeof(buf_bf));
 		if (ret < 0)
 			return ret;

 		/* time = br/(32* fxtal) */
 		/* minimal sleep time to be calculated
 		 * maximum br is 63 -> max time = 2 /10 MHz = 2e-7 */
 		msleep(1);

 		ret = zl10036_write(state, zl10036_rsd_off,
 			sizeof(zl10036_rsd_off));
 		if (ret < 0)
 			return ret;
 	}

 	state->br = br;
 	state->bf = bf;

 	return 0;
 }

 static int zl10036_set_gain_params(struct zl10036_state *state,
 	int c)
 {
 	u8 buf[2];
 	u8 rfg, ba, bg;

 	/* default values */
 	rfg = 0; /* enable when using an lna */
 	ba = 1;
 	bg = 1;

 	/* reg 4 */
 	buf[0] = 0x80 | ((rfg << 5) & 0x20)
 		| ((ba  << 3) & 0x18) | ((bg  << 1) & 0x06);

 	if (!state->config->rf_loop_enable)
 		buf[0] |= 0x01;

 	/* P0=0 */
 	buf[1] = _RDIV_REG | ((c << 5) & 0x60);

 	deb_info("%s: c=%u rfg=%u ba=%u bg=%u\n", __func__, c, rfg, ba, bg);
 	return zl10036_write(state, buf, sizeof(buf));
 }

 static int zl10036_set_params(struct dvb_frontend *fe)
 {
 	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
 	struct zl10036_state *state = fe->tuner_priv;
 	int ret = 0;
 	u32 frequency = p->frequency;
 	u32 fbw;
 	int i;
 	u8 c;

 	/* ensure correct values
 	 * maybe redundant as core already checks this */
 	if ((frequency < fe->ops.info.frequency_min_hz / kHz)
 	||  (frequency > fe->ops.info.frequency_max_hz / kHz))
 		return -EINVAL;

 	/*
 	 * alpha = 1.35 for dvb-s
 	 * fBW = (alpha*symbolrate)/(2*0.8)
 	 * 1.35 / (2*0.8) = 27 / 32
 	 */
 	fbw = (27 * p->symbol_rate) / 32;

 	/* scale to kHz */
 	fbw /= 1000;

 	/* Add safe margin of 3MHz */
 	fbw += 3000;

 	/* setting the charge pump - guessed values */
 	if (frequency < 950000)
 		return -EINVAL;
 	else if (frequency < 1250000)
 		c = 0;
 	else if (frequency < 1750000)
 		c = 1;
 	else if (frequency < 2175000)
 		c = 2;
 	else
 		return -EINVAL;

 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */

 	ret = zl10036_set_gain_params(state, c);
 	if (ret < 0)
 		goto error;

 	ret = zl10036_set_frequency(state, p->frequency);
 	if (ret < 0)
 		goto error;

 	ret = zl10036_set_bandwidth(state, fbw);
 	if (ret < 0)
 		goto error;

 	/* wait for tuner lock - no idea if this is really needed */
 	for (i = 0; i < 20; i++) {
 		ret = zl10036_read_status_reg(state);
 		if (ret < 0)
 			goto error;

 		/* check Frequency & Phase Lock Bit */
 		if (ret & STATUS_FL)
 			break;

 		msleep(10);
 	}

 error:
 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */

 	return ret;
 }

 static int zl10036_get_frequency(struct dvb_frontend *fe, u32 *frequency)
 {
 	struct zl10036_state *state = fe->tuner_priv;

 	*frequency = state->frequency;

 	return 0;
 }

 static int zl10036_init_regs(struct zl10036_state *state)
 {
 	int ret;
 	int i;

 	/* could also be one block from reg 2 to 13 and additional 10/11 */
 	u8 zl10036_init_tab[][2] = {
 		{ 0x04, 0x00 },		/*   2/3: div=0x400 - arbitrary value */
 		{ 0x8b, _RDIV_REG },	/*   4/5: rfg=0 ba=1 bg=1 len=? */
 					/*        p0=0 c=0 r=_RDIV_REG */
 		{ 0xc0, 0x20 },		/*   6/7: rsd=0 bf=0x10 */
 		{ 0xd3, 0x40 },		/*   8/9: from datasheet */
 		{ 0xe3, 0x5b },		/* 10/11: lock window level */
 		{ 0xf0, 0x28 },		/* 12/13: br=0xa clr=0 tl=0*/
 		{ 0xe3, 0xf9 },		/* 10/11: unlock window level */
 	};

 	/* invalid values to trigger writing */
 	state->br = 0xff;
 	state->bf = 0xff;

 	if (!state->config->rf_loop_enable)
 		zl10036_init_tab[1][0] |= 0x01;

 	deb_info("%s\n", __func__);

 	for (i = 0; i < ARRAY_SIZE(zl10036_init_tab); i++) {
 		ret = zl10036_write(state, zl10036_init_tab[i], 2);
 		if (ret < 0)
 			return ret;
 	}

 	return 0;
 }

 static int zl10036_init(struct dvb_frontend *fe)
 {
 	struct zl10036_state *state = fe->tuner_priv;
 	int ret = 0;

 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */

 	ret = zl10036_read_status_reg(state);
 	if (ret < 0)
 		return ret;

 	/* Only init if Power-on-Reset bit is set? */
 	ret = zl10036_init_regs(state);

 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */

 	return ret;
 }

 static const struct dvb_tuner_ops zl10036_tuner_ops = {
 	.info = {
 		.name = "Zarlink ZL10036",
 		.frequency_min_hz =  950 * MHz,
 		.frequency_max_hz = 2175 * MHz
 	},
 	.init = zl10036_init,
 	.release = zl10036_release,
 	.sleep = zl10036_sleep,
 	.set_params = zl10036_set_params,
 	.get_frequency = zl10036_get_frequency,
 };

 struct dvb_frontend *zl10036_attach(struct dvb_frontend *fe,
 				    const struct zl10036_config *config,
 				    struct i2c_adapter *i2c)
 {
 	struct zl10036_state *state;
 	int ret;

 	if (!config) {
 		printk(KERN_ERR "%s: no config specified", __func__);
 		return NULL;
 	}

 	state = kzalloc(sizeof(struct zl10036_state), GFP_KERNEL);
 	if (!state)
 		return NULL;

 	state->config = config;
 	state->i2c = i2c;

 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */

 	ret = zl10036_read_status_reg(state);
 	if (ret < 0) {
 		printk(KERN_ERR "%s: No zl10036 found\n", __func__);
 		goto error;
 	}

 	ret = zl10036_init_regs(state);
 	if (ret < 0) {
 		printk(KERN_ERR "%s: tuner initialization failed\n",
 			__func__);
 		goto error;
 	}

 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */

 	fe->tuner_priv = state;

 	memcpy(&fe->ops.tuner_ops, &zl10036_tuner_ops,
 		sizeof(struct dvb_tuner_ops));
 	printk(KERN_INFO "%s: tuner initialization (%s addr=0x%02x) ok\n",
 		__func__, fe->ops.tuner_ops.info.name, config->tuner_address);

 	return fe;

 error:
 	kfree(state);
 	return NULL;
 }
 EXPORT_SYMBOL_GPL(zl10036_attach);

 module_param_named(debug, zl10036_debug, int, 0644);
 MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
 MODULE_DESCRIPTION("DVB ZL10036 driver");
 MODULE_AUTHOR("Tino Reichardt");
 MODULE_AUTHOR("Matthias Schwarzott");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Driver for Zarlink zl10036 DVB-S silicon tuner
	*
	* Copyright (C) 2006 Tino Reichardt
	* Copyright (C) 2007-2009 Matthias Schwarzott <zzam@gentoo.de>
	*
	**
	* The data sheet for this tuner can be found at:
	* http://www.mcmilk.de/projects/dvb-card/datasheets/ZL10036.pdf
	*
	* This one is working: (at my Avermedia DVB-S Pro)
	* - zl10036 (40pin, FTA)
	*
	* A driver for zl10038 should be very similar.
	*/

	#include <linux/module.h>
	#include <linux/dvb/frontend.h>
	#include <linux/slab.h>
	#include <linux/types.h>

	#include "zl10036.h"

	static int zl10036_debug;
	#define dprintk(level, args...) \
	do { if (zl10036_debug & level) printk(KERN_DEBUG "zl10036: " args); \
	} while (0)

	#define deb_info(args...) dprintk(0x01, args)
	#define deb_i2c(args...) dprintk(0x02, args)

	struct zl10036_state {
	struct i2c_adapter *i2c;
	const struct zl10036_config *config;
	u32 frequency;
	u8 br, bf;
	};


	/* This driver assumes the tuner is driven by a 10.111MHz Cristal */
	#define _XTAL 10111

	/* Some of the possible dividers:
	* 64, (write 0x05 to reg), freq step size 158kHz
	* 10, (write 0x0a to reg), freq step size 1.011kHz (used here)
	* 5, (write 0x09 to reg), freq step size 2.022kHz
	*/

	#define _RDIV 10
	#define _RDIV_REG 0x0a
	#define _FR (_XTAL/_RDIV)

	#define STATUS_POR 0x80 /* Power on Reset */
	#define STATUS_FL 0x40 /* Frequency & Phase Lock */

	/* read/write for zl10036 and zl10038 */

	static int zl10036_read_status_reg(struct zl10036_state *state)
	{
	u8 status;
	struct i2c_msg msg[1] = {
	{ .addr = state->config->tuner_address, .flags = I2C_M_RD,
	.buf = &status, .len = sizeof(status) },
	};

	if (i2c_transfer(state->i2c, msg, 1) != 1) {
	printk(KERN_ERR "%s: i2c read failed at addr=%02x\n",
	__func__, state->config->tuner_address);
	return -EIO;
	}

	deb_i2c("R(status): %02x [FL=%d]\n", status,
	(status & STATUS_FL) ? 1 : 0);
	if (status & STATUS_POR)
	deb_info("%s: Power-On-Reset bit enabled - need to initialize the tuner\n",
	__func__);

	return status;
	}

	static int zl10036_write(struct zl10036_state *state, u8 buf[], u8 count)
	{
	struct i2c_msg msg[1] = {
	{ .addr = state->config->tuner_address, .flags = 0,
	.buf = buf, .len = count },
	};
	u8 reg = 0;
	int ret;

	if (zl10036_debug & 0x02) {
	/* every 8bit-value satisifes this!
	* so only check for debug log */
	if ((buf[0] & 0x80) == 0x00)
	reg = 2;
	else if ((buf[0] & 0xc0) == 0x80)
	reg = 4;
	else if ((buf[0] & 0xf0) == 0xc0)
	reg = 6;
	else if ((buf[0] & 0xf0) == 0xd0)
	reg = 8;
	else if ((buf[0] & 0xf0) == 0xe0)
	reg = 10;
	else if ((buf[0] & 0xf0) == 0xf0)
	reg = 12;

	deb_i2c("W(%d):", reg);
	{
	int i;
	for (i = 0; i < count; i++)
	printk(KERN_CONT " %02x", buf[i]);
	printk(KERN_CONT "\n");
	}
	}

	ret = i2c_transfer(state->i2c, msg, 1);
	if (ret != 1) {
	printk(KERN_ERR "%s: i2c error, ret=%d\n", __func__, ret);
	return -EIO;
	}

	return 0;
	}

	static void zl10036_release(struct dvb_frontend *fe)
	{
	struct zl10036_state *state = fe->tuner_priv;

	fe->tuner_priv = NULL;
	kfree(state);
	}

	static int zl10036_sleep(struct dvb_frontend *fe)
	{
	struct zl10036_state *state = fe->tuner_priv;
	u8 buf[] = { 0xf0, 0x80 }; /* regs 12/13 */
	int ret;

	deb_info("%s\n", __func__);

	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */

	ret = zl10036_write(state, buf, sizeof(buf));

	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */

	return ret;
	}

	/*
	* register map of the ZL10036/ZL10038
	*
	* reg[default] content
	* 2[0x00]: 0 \| N14 \| N13 \| N12 \| N11 \| N10 \| N9 \| N8
	* 3[0x00]: N7 \| N6 \| N5 \| N4 \| N3 \| N2 \| N1 \| N0
	* 4[0x80]: 1 \| 0 \| RFG \| BA1 \| BA0 \| BG1 \| BG0 \| LEN
	* 5[0x00]: P0 \| C1 \| C0 \| R4 \| R3 \| R2 \| R1 \| R0
	* 6[0xc0]: 1 \| 1 \| 0 \| 0 \| RSD \| 0 \| 0 \| 0
	* 7[0x20]: P1 \| BF6 \| BF5 \| BF4 \| BF3 \| BF2 \| BF1 \| 0
	* 8[0xdb]: 1 \| 1 \| 0 \| 1 \| 0 \| CC \| 1 \| 1
	* 9[0x30]: VSD \| V2 \| V1 \| V0 \| S3 \| S2 \| S1 \| S0
	* 10[0xe1]: 1 \| 1 \| 1 \| 0 \| 0 \| LS2 \| LS1 \| LS0
	* 11[0xf5]: WS \| WH2 \| WH1 \| WH0 \| WL2 \| WL1 \| WL0 \| WRE
	* 12[0xf0]: 1 \| 1 \| 1 \| 1 \| 0 \| 0 \| 0 \| 0
	* 13[0x28]: PD \| BR4 \| BR3 \| BR2 \| BR1 \| BR0 \| CLR \| TL
	*/

	static int zl10036_set_frequency(struct zl10036_state *state, u32 frequency)
	{
	u8 buf[2];
	u32 div, foffset;

	div = (frequency + _FR/2) / _FR;
	state->frequency = div * _FR;

	foffset = frequency - state->frequency;

	buf[0] = (div >> 8) & 0x7f;
	buf[1] = (div >> 0) & 0xff;

	deb_info("%s: ftodo=%u fpriv=%u ferr=%d div=%u\n", __func__,
	frequency, state->frequency, foffset, div);

	return zl10036_write(state, buf, sizeof(buf));
	}

	static int zl10036_set_bandwidth(struct zl10036_state *state, u32 fbw)
	{
	/* fbw is measured in kHz */
	u8 br, bf;
	int ret;
	u8 buf_bf[] = {
	0xc0, 0x00, /* 6/7: rsd=0 bf=0 */
	};
	u8 buf_br[] = {
	0xf0, 0x00, /* 12/13: br=0xa clr=0 tl=0*/
	};
	u8 zl10036_rsd_off[] = { 0xc8 }; /* set RSD=1 */

	/* ensure correct values */
	if (fbw > 35000)
	fbw = 35000;
	if (fbw < 8000)
	fbw = 8000;

	#define _BR_MAXIMUM (_XTAL/575) /* _XTAL / 575kHz = 17 */

	/* <= 28,82 MHz */
	if (fbw <= 28820) {
	br = _BR_MAXIMUM;
	} else {
	/*
	* f(bw)=34,6MHz f(xtal)=10.111MHz
	* br = (10111/34600) * 63 * 1/K = 14;
	*/
	br = ((_XTAL * 21 * 1000) / (fbw * 419));
	}

	/* ensure correct values */
	if (br < 4)
	br = 4;
	if (br > _BR_MAXIMUM)
	br = _BR_MAXIMUM;

	/*
	* k = 1.257
	* bf = fbw/_XTAL * br * k - 1 */

	bf = (fbw * br * 1257) / (_XTAL * 1000) - 1;

	/* ensure correct values */
	if (bf > 62)
	bf = 62;

	buf_bf[1] = (bf << 1) & 0x7e;
	buf_br[1] = (br << 2) & 0x7c;
	deb_info("%s: BW=%d br=%u bf=%u\n", __func__, fbw, br, bf);

	if (br != state->br) {
	ret = zl10036_write(state, buf_br, sizeof(buf_br));
	if (ret < 0)
	return ret;
	}

	if (bf != state->bf) {
	ret = zl10036_write(state, buf_bf, sizeof(buf_bf));
	if (ret < 0)
	return ret;

	/* time = br/(32* fxtal) */
	/* minimal sleep time to be calculated
	* maximum br is 63 -> max time = 2 /10 MHz = 2e-7 */
	msleep(1);

	ret = zl10036_write(state, zl10036_rsd_off,
	sizeof(zl10036_rsd_off));
	if (ret < 0)
	return ret;
	}

	state->br = br;
	state->bf = bf;

	return 0;
	}

	static int zl10036_set_gain_params(struct zl10036_state *state,
	int c)
	{
	u8 buf[2];
	u8 rfg, ba, bg;

	/* default values */
	rfg = 0; /* enable when using an lna */
	ba = 1;
	bg = 1;

	/* reg 4 */
	buf[0] = 0x80 \| ((rfg << 5) & 0x20)
	\| ((ba << 3) & 0x18) \| ((bg << 1) & 0x06);

	if (!state->config->rf_loop_enable)
	buf[0] \|= 0x01;

	/* P0=0 */
	buf[1] = _RDIV_REG \| ((c << 5) & 0x60);

	deb_info("%s: c=%u rfg=%u ba=%u bg=%u\n", __func__, c, rfg, ba, bg);
	return zl10036_write(state, buf, sizeof(buf));
	}

	static int zl10036_set_params(struct dvb_frontend *fe)
	{
	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
	struct zl10036_state *state = fe->tuner_priv;
	int ret = 0;
	u32 frequency = p->frequency;
	u32 fbw;
	int i;
	u8 c;

	/* ensure correct values
	* maybe redundant as core already checks this */
	if ((frequency < fe->ops.info.frequency_min_hz / kHz)
	\|\| (frequency > fe->ops.info.frequency_max_hz / kHz))
	return -EINVAL;

	/*
	* alpha = 1.35 for dvb-s
	* fBW = (alphasymbolrate)/(20.8)
	* 1.35 / (2*0.8) = 27 / 32
	*/
	fbw = (27 * p->symbol_rate) / 32;

	/* scale to kHz */
	fbw /= 1000;

	/* Add safe margin of 3MHz */
	fbw += 3000;

	/* setting the charge pump - guessed values */
	if (frequency < 950000)
	return -EINVAL;
	else if (frequency < 1250000)
	c = 0;
	else if (frequency < 1750000)
	c = 1;
	else if (frequency < 2175000)
	c = 2;
	else
	return -EINVAL;

	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */

	ret = zl10036_set_gain_params(state, c);
	if (ret < 0)
	goto error;

	ret = zl10036_set_frequency(state, p->frequency);
	if (ret < 0)
	goto error;

	ret = zl10036_set_bandwidth(state, fbw);
	if (ret < 0)
	goto error;

	/* wait for tuner lock - no idea if this is really needed */
	for (i = 0; i < 20; i++) {
	ret = zl10036_read_status_reg(state);
	if (ret < 0)
	goto error;

	/* check Frequency & Phase Lock Bit */
	if (ret & STATUS_FL)
	break;

	msleep(10);
	}

	error:
	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */

	return ret;
	}

	static int zl10036_get_frequency(struct dvb_frontend fe, u32 frequency)
	{
	struct zl10036_state *state = fe->tuner_priv;

	*frequency = state->frequency;

	return 0;
	}

	static int zl10036_init_regs(struct zl10036_state *state)
	{
	int ret;
	int i;

	/* could also be one block from reg 2 to 13 and additional 10/11 */
	u8 zl10036_init_tab[][2] = {
	{ 0x04, 0x00 }, /* 2/3: div=0x400 - arbitrary value */
	{ 0x8b, _RDIV_REG }, /* 4/5: rfg=0 ba=1 bg=1 len=? */
	/* p0=0 c=0 r=_RDIV_REG */
	{ 0xc0, 0x20 }, /* 6/7: rsd=0 bf=0x10 */
	{ 0xd3, 0x40 }, /* 8/9: from datasheet */
	{ 0xe3, 0x5b }, /* 10/11: lock window level */
	{ 0xf0, 0x28 }, /* 12/13: br=0xa clr=0 tl=0*/
	{ 0xe3, 0xf9 }, /* 10/11: unlock window level */
	};

	/* invalid values to trigger writing */
	state->br = 0xff;
	state->bf = 0xff;

	if (!state->config->rf_loop_enable)
	zl10036_init_tab[1][0] \|= 0x01;

	deb_info("%s\n", __func__);

	for (i = 0; i < ARRAY_SIZE(zl10036_init_tab); i++) {
	ret = zl10036_write(state, zl10036_init_tab[i], 2);
	if (ret < 0)
	return ret;
	}

	return 0;
	}

	static int zl10036_init(struct dvb_frontend *fe)
	{
	struct zl10036_state *state = fe->tuner_priv;
	int ret = 0;

	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */

	ret = zl10036_read_status_reg(state);
	if (ret < 0)
	return ret;

	/* Only init if Power-on-Reset bit is set? */
	ret = zl10036_init_regs(state);

	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */

	return ret;
	}

	static const struct dvb_tuner_ops zl10036_tuner_ops = {
	.info = {
	.name = "Zarlink ZL10036",
	.frequency_min_hz = 950 * MHz,
	.frequency_max_hz = 2175 * MHz
	},
	.init = zl10036_init,
	.release = zl10036_release,
	.sleep = zl10036_sleep,
	.set_params = zl10036_set_params,
	.get_frequency = zl10036_get_frequency,
	};

	struct dvb_frontend zl10036_attach(struct dvb_frontend fe,
	const struct zl10036_config *config,
	struct i2c_adapter *i2c)
	{
	struct zl10036_state *state;
	int ret;

	if (!config) {
	printk(KERN_ERR "%s: no config specified", __func__);
	return NULL;
	}

	state = kzalloc(sizeof(struct zl10036_state), GFP_KERNEL);
	if (!state)
	return NULL;

	state->config = config;
	state->i2c = i2c;

	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */

	ret = zl10036_read_status_reg(state);
	if (ret < 0) {
	printk(KERN_ERR "%s: No zl10036 found\n", __func__);
	goto error;
	}

	ret = zl10036_init_regs(state);
	if (ret < 0) {
	printk(KERN_ERR "%s: tuner initialization failed\n",
	__func__);
	goto error;
	}

	if (fe->ops.i2c_gate_ctrl)
	fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */

	fe->tuner_priv = state;

	memcpy(&fe->ops.tuner_ops, &zl10036_tuner_ops,
	sizeof(struct dvb_tuner_ops));
	printk(KERN_INFO "%s: tuner initialization (%s addr=0x%02x) ok\n",
	__func__, fe->ops.tuner_ops.info.name, config->tuner_address);

	return fe;

	error:
	kfree(state);
	return NULL;
	}
	EXPORT_SYMBOL_GPL(zl10036_attach);

	module_param_named(debug, zl10036_debug, int, 0644);
	MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
	MODULE_DESCRIPTION("DVB ZL10036 driver");
	MODULE_AUTHOR("Tino Reichardt");
	MODULE_AUTHOR("Matthias Schwarzott");
	MODULE_LICENSE("GPL");