drivers/media/dvb-frontends/tda10021.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
     TDA10021  - Single Chip Cable Channel Receiver driver module
 	       used on the Siemens DVB-C cards

     Copyright (C) 1999 Convergence Integrated Media GmbH <ralph@convergence.de>
     Copyright (C) 2004 Markus Schulz <msc@antzsystem.de>
 		   Support for TDA10021

 */

 #include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/string.h>
 #include <linux/slab.h>

 #include <media/dvb_frontend.h>
 #include "tda1002x.h"


 struct tda10021_state {
 	struct i2c_adapter* i2c;
 	/* configuration settings */
 	const struct tda1002x_config* config;
 	struct dvb_frontend frontend;

 	u8 pwm;
 	u8 reg0;
 };


 #if 0
 #define dprintk(x...) printk(x)
 #else
 #define dprintk(x...)
 #endif

 static int verbose;

 #define XIN 57840000UL

 #define FIN (XIN >> 4)

 static int tda10021_inittab_size = 0x40;
 static u8 tda10021_inittab[0x40]=
 {
 	0x73, 0x6a, 0x23, 0x0a, 0x02, 0x37, 0x77, 0x1a,
 	0x37, 0x6a, 0x17, 0x8a, 0x1e, 0x86, 0x43, 0x40,
 	0xb8, 0x3f, 0xa1, 0x00, 0xcd, 0x01, 0x00, 0xff,
 	0x11, 0x00, 0x7c, 0x31, 0x30, 0x20, 0x00, 0x00,
 	0x02, 0x00, 0x00, 0x7d, 0x00, 0x00, 0x00, 0x00,
 	0x07, 0x00, 0x33, 0x11, 0x0d, 0x95, 0x08, 0x58,
 	0x00, 0x00, 0x80, 0x00, 0x80, 0xff, 0x00, 0x00,
 	0x04, 0x2d, 0x2f, 0xff, 0x00, 0x00, 0x00, 0x00,
 };

 static int _tda10021_writereg (struct tda10021_state* state, u8 reg, u8 data)
 {
 	u8 buf[] = { reg, data };
 	struct i2c_msg msg = { .addr = state->config->demod_address, .flags = 0, .buf = buf, .len = 2 };
 	int ret;

 	ret = i2c_transfer (state->i2c, &msg, 1);
 	if (ret != 1)
 		printk("DVB: TDA10021(%d): %s, writereg error (reg == 0x%02x, val == 0x%02x, ret == %i)\n",
 			state->frontend.dvb->num, __func__, reg, data, ret);

 	msleep(10);
 	return (ret != 1) ? -EREMOTEIO : 0;
 }

 static u8 tda10021_readreg (struct tda10021_state* state, u8 reg)
 {
 	u8 b0 [] = { reg };
 	u8 b1 [] = { 0 };
 	struct i2c_msg msg [] = { { .addr = state->config->demod_address, .flags = 0, .buf = b0, .len = 1 },
 				  { .addr = state->config->demod_address, .flags = I2C_M_RD, .buf = b1, .len = 1 } };
 	int ret;

 	ret = i2c_transfer (state->i2c, msg, 2);
 	// Don't print an error message if the id is read.
 	if (ret != 2 && reg != 0x1a)
 		printk("DVB: TDA10021: %s: readreg error (ret == %i)\n",
 				__func__, ret);
 	return b1[0];
 }

 //get access to tuner
 static int lock_tuner(struct tda10021_state* state)
 {
 	u8 buf[2] = { 0x0f, tda10021_inittab[0x0f] | 0x80 };
 	struct i2c_msg msg = {.addr=state->config->demod_address, .flags=0, .buf=buf, .len=2};

 	if(i2c_transfer(state->i2c, &msg, 1) != 1)
 	{
 		printk("tda10021: lock tuner fails\n");
 		return -EREMOTEIO;
 	}
 	return 0;
 }

 //release access from tuner
 static int unlock_tuner(struct tda10021_state* state)
 {
 	u8 buf[2] = { 0x0f, tda10021_inittab[0x0f] & 0x7f };
 	struct i2c_msg msg_post={.addr=state->config->demod_address, .flags=0, .buf=buf, .len=2};

 	if(i2c_transfer(state->i2c, &msg_post, 1) != 1)
 	{
 		printk("tda10021: unlock tuner fails\n");
 		return -EREMOTEIO;
 	}
 	return 0;
 }

 static int tda10021_setup_reg0(struct tda10021_state *state, u8 reg0,
 			       enum fe_spectral_inversion inversion)
 {
 	reg0 |= state->reg0 & 0x63;

 	if ((INVERSION_ON == inversion) ^ (state->config->invert == 0))
 		reg0 &= ~0x20;
 	else
 		reg0 |= 0x20;

 	_tda10021_writereg (state, 0x00, reg0 & 0xfe);
 	_tda10021_writereg (state, 0x00, reg0 | 0x01);

 	state->reg0 = reg0;
 	return 0;
 }

 static int tda10021_set_symbolrate (struct tda10021_state* state, u32 symbolrate)
 {
 	s32 BDR;
 	s32 BDRI;
 	s16 SFIL = 0;
 	u16 NDEC = 0;
 	u32 tmp, ratio;

 	if (symbolrate > XIN / 2)
 		symbolrate = XIN / 2;
 	else if (symbolrate < 500000)
 		symbolrate = 500000;

 	if (symbolrate < XIN / 16)
 		NDEC = 1;
 	if (symbolrate < XIN / 32)
 		NDEC = 2;
 	if (symbolrate < XIN / 64)
 		NDEC = 3;

 	if (symbolrate < XIN * 10 / 123)
 		SFIL = 1;
 	if (symbolrate < XIN * 10 / 160)
 		SFIL = 0;
 	if (symbolrate < XIN * 10 / 246)
 		SFIL = 1;
 	if (symbolrate < XIN * 10 / 320)
 		SFIL = 0;
 	if (symbolrate < XIN * 10 / 492)
 		SFIL = 1;
 	if (symbolrate < XIN * 10 / 640)
 		SFIL = 0;
 	if (symbolrate < XIN * 10 / 984)
 		SFIL = 1;

 	symbolrate <<= NDEC;
 	ratio = (symbolrate << 4) / FIN;
 	tmp =  ((symbolrate << 4) % FIN) << 8;
 	ratio = (ratio << 8) + tmp / FIN;
 	tmp = (tmp % FIN) << 8;
 	ratio = (ratio << 8) + DIV_ROUND_CLOSEST(tmp, FIN);

 	BDR = ratio;
 	BDRI = (((XIN << 5) / symbolrate) + 1) / 2;

 	if (BDRI > 0xFF)
 		BDRI = 0xFF;

 	SFIL = (SFIL << 4) | tda10021_inittab[0x0E];

 	NDEC = (NDEC << 6) | tda10021_inittab[0x03];

 	_tda10021_writereg (state, 0x03, NDEC);
 	_tda10021_writereg (state, 0x0a, BDR&0xff);
 	_tda10021_writereg (state, 0x0b, (BDR>> 8)&0xff);
 	_tda10021_writereg (state, 0x0c, (BDR>>16)&0x3f);

 	_tda10021_writereg (state, 0x0d, BDRI);
 	_tda10021_writereg (state, 0x0e, SFIL);

 	return 0;
 }

 static int tda10021_init (struct dvb_frontend *fe)
 {
 	struct tda10021_state* state = fe->demodulator_priv;
 	int i;

 	dprintk("DVB: TDA10021(%d): init chip\n", fe->adapter->num);

 	//_tda10021_writereg (fe, 0, 0);

 	for (i=0; i<tda10021_inittab_size; i++)
 		_tda10021_writereg (state, i, tda10021_inittab[i]);

 	_tda10021_writereg (state, 0x34, state->pwm);

 	//Comment by markus
 	//0x2A[3-0] == PDIV -> P multiplaying factor (P=PDIV+1)(default 0)
 	//0x2A[4] == BYPPLL -> Power down mode (default 1)
 	//0x2A[5] == LCK -> PLL Lock Flag
 	//0x2A[6] == POLAXIN -> Polarity of the input reference clock (default 0)

 	//Activate PLL
 	_tda10021_writereg(state, 0x2a, tda10021_inittab[0x2a] & 0xef);
 	return 0;
 }

 struct qam_params {
 	u8 conf, agcref, lthr, mseth, aref;
 };

 static int tda10021_set_parameters(struct dvb_frontend *fe)
 {
 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
 	u32 delsys  = c->delivery_system;
 	unsigned qam = c->modulation;
 	bool is_annex_c;
 	u32 reg0x3d;
 	struct tda10021_state* state = fe->demodulator_priv;
 	static const struct qam_params qam_params[] = {
 		/* Modulation  Conf  AGCref  LTHR  MSETH  AREF */
 		[QPSK]	   = { 0x14, 0x78,   0x78, 0x8c,  0x96 },
 		[QAM_16]   = { 0x00, 0x8c,   0x87, 0xa2,  0x91 },
 		[QAM_32]   = { 0x04, 0x8c,   0x64, 0x74,  0x96 },
 		[QAM_64]   = { 0x08, 0x6a,   0x46, 0x43,  0x6a },
 		[QAM_128]  = { 0x0c, 0x78,   0x36, 0x34,  0x7e },
 		[QAM_256]  = { 0x10, 0x5c,   0x26, 0x23,  0x6b },
 	};

 	switch (delsys) {
 	case SYS_DVBC_ANNEX_A:
 		is_annex_c = false;
 		break;
 	case SYS_DVBC_ANNEX_C:
 		is_annex_c = true;
 		break;
 	default:
 		return -EINVAL;
 	}

 	/*
 	 * gcc optimizes the code below the same way as it would code:
 	 *           "if (qam > 5) return -EINVAL;"
 	 * Yet, the code is clearer, as it shows what QAM standards are
 	 * supported by the driver, and avoids the usage of magic numbers on
 	 * it.
 	 */
 	switch (qam) {
 	case QPSK:
 	case QAM_16:
 	case QAM_32:
 	case QAM_64:
 	case QAM_128:
 	case QAM_256:
 		break;
 	default:
 		return -EINVAL;
 	}

 	if (c->inversion != INVERSION_ON && c->inversion != INVERSION_OFF)
 		return -EINVAL;

 	/*printk("tda10021: set frequency to %d qam=%d symrate=%d\n", p->frequency,qam,p->symbol_rate);*/

 	if (fe->ops.tuner_ops.set_params) {
 		fe->ops.tuner_ops.set_params(fe);
 		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
 	}

 	tda10021_set_symbolrate(state, c->symbol_rate);
 	_tda10021_writereg(state, 0x34, state->pwm);

 	_tda10021_writereg(state, 0x01, qam_params[qam].agcref);
 	_tda10021_writereg(state, 0x05, qam_params[qam].lthr);
 	_tda10021_writereg(state, 0x08, qam_params[qam].mseth);
 	_tda10021_writereg(state, 0x09, qam_params[qam].aref);

 	/*
 	 * Bit 0 == 0 means roll-off = 0.15 (Annex A)
 	 *	 == 1 means roll-off = 0.13 (Annex C)
 	 */
 	reg0x3d = tda10021_readreg (state, 0x3d);
 	if (is_annex_c)
 		_tda10021_writereg (state, 0x3d, 0x01 | reg0x3d);
 	else
 		_tda10021_writereg (state, 0x3d, 0xfe & reg0x3d);
 	tda10021_setup_reg0(state, qam_params[qam].conf, c->inversion);

 	return 0;
 }

 static int tda10021_read_status(struct dvb_frontend *fe,
 				enum fe_status *status)
 {
 	struct tda10021_state* state = fe->demodulator_priv;
 	int sync;

 	*status = 0;
 	//0x11[0] == EQALGO -> Equalizer algorithms state
 	//0x11[1] == CARLOCK -> Carrier locked
 	//0x11[2] == FSYNC -> Frame synchronisation
 	//0x11[3] == FEL -> Front End locked
 	//0x11[6] == NODVB -> DVB Mode Information
 	sync = tda10021_readreg (state, 0x11);

 	if (sync & 2)
 		*status |= FE_HAS_SIGNAL|FE_HAS_CARRIER;

 	if (sync & 4)
 		*status |= FE_HAS_SYNC|FE_HAS_VITERBI;

 	if (sync & 8)
 		*status |= FE_HAS_LOCK;

 	return 0;
 }

 static int tda10021_read_ber(struct dvb_frontend* fe, u32* ber)
 {
 	struct tda10021_state* state = fe->demodulator_priv;

 	u32 _ber = tda10021_readreg(state, 0x14) |
 		(tda10021_readreg(state, 0x15) << 8) |
 		((tda10021_readreg(state, 0x16) & 0x0f) << 16);
 	_tda10021_writereg(state, 0x10, (tda10021_readreg(state, 0x10) & ~0xc0)
 					| (tda10021_inittab[0x10] & 0xc0));
 	*ber = 10 * _ber;

 	return 0;
 }

 static int tda10021_read_signal_strength(struct dvb_frontend* fe, u16* strength)
 {
 	struct tda10021_state* state = fe->demodulator_priv;

 	u8 config = tda10021_readreg(state, 0x02);
 	u8 gain = tda10021_readreg(state, 0x17);
 	if (config & 0x02)
 		/* the agc value is inverted */
 		gain = ~gain;
 	*strength = (gain << 8) | gain;

 	return 0;
 }

 static int tda10021_read_snr(struct dvb_frontend* fe, u16* snr)
 {
 	struct tda10021_state* state = fe->demodulator_priv;

 	u8 quality = ~tda10021_readreg(state, 0x18);
 	*snr = (quality << 8) | quality;

 	return 0;
 }

 static int tda10021_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
 {
 	struct tda10021_state* state = fe->demodulator_priv;

 	*ucblocks = tda10021_readreg (state, 0x13) & 0x7f;
 	if (*ucblocks == 0x7f)
 		*ucblocks = 0xffffffff;

 	/* reset uncorrected block counter */
 	_tda10021_writereg (state, 0x10, tda10021_inittab[0x10] & 0xdf);
 	_tda10021_writereg (state, 0x10, tda10021_inittab[0x10]);

 	return 0;
 }

 static int tda10021_get_frontend(struct dvb_frontend *fe,
 				 struct dtv_frontend_properties *p)
 {
 	struct tda10021_state* state = fe->demodulator_priv;
 	int sync;
 	s8 afc = 0;

 	sync = tda10021_readreg(state, 0x11);
 	afc = tda10021_readreg(state, 0x19);
 	if (verbose) {
 		/* AFC only valid when carrier has been recovered */
 		printk(sync & 2 ? "DVB: TDA10021(%d): AFC (%d) %dHz\n" :
 				  "DVB: TDA10021(%d): [AFC (%d) %dHz]\n",
 			state->frontend.dvb->num, afc,
 		       -((s32)p->symbol_rate * afc) >> 10);
 	}

 	p->inversion = ((state->reg0 & 0x20) == 0x20) ^ (state->config->invert != 0) ? INVERSION_ON : INVERSION_OFF;
 	p->modulation = ((state->reg0 >> 2) & 7) + QAM_16;

 	p->fec_inner = FEC_NONE;
 	p->frequency = ((p->frequency + 31250) / 62500) * 62500;

 	if (sync & 2)
 		p->frequency -= ((s32)p->symbol_rate * afc) >> 10;

 	return 0;
 }

 static int tda10021_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
 {
 	struct tda10021_state* state = fe->demodulator_priv;

 	if (enable) {
 		lock_tuner(state);
 	} else {
 		unlock_tuner(state);
 	}
 	return 0;
 }

 static int tda10021_sleep(struct dvb_frontend* fe)
 {
 	struct tda10021_state* state = fe->demodulator_priv;

 	_tda10021_writereg (state, 0x1b, 0x02);  /* pdown ADC */
 	_tda10021_writereg (state, 0x00, 0x80);  /* standby */

 	return 0;
 }

 static void tda10021_release(struct dvb_frontend* fe)
 {
 	struct tda10021_state* state = fe->demodulator_priv;
 	kfree(state);
 }

 static const struct dvb_frontend_ops tda10021_ops;

 struct dvb_frontend* tda10021_attach(const struct tda1002x_config* config,
 				     struct i2c_adapter* i2c,
 				     u8 pwm)
 {
 	struct tda10021_state* state = NULL;
 	u8 id;

 	/* allocate memory for the internal state */
 	state = kzalloc(sizeof(struct tda10021_state), GFP_KERNEL);
 	if (state == NULL) goto error;

 	/* setup the state */
 	state->config = config;
 	state->i2c = i2c;
 	state->pwm = pwm;
 	state->reg0 = tda10021_inittab[0];

 	/* check if the demod is there */
 	id = tda10021_readreg(state, 0x1a);
 	if ((id & 0xf0) != 0x70) goto error;

 	/* Don't claim TDA10023 */
 	if (id == 0x7d)
 		goto error;

 	printk("TDA10021: i2c-addr = 0x%02x, id = 0x%02x\n",
 	       state->config->demod_address, id);

 	/* create dvb_frontend */
 	memcpy(&state->frontend.ops, &tda10021_ops, sizeof(struct dvb_frontend_ops));
 	state->frontend.demodulator_priv = state;
 	return &state->frontend;

 error:
 	kfree(state);
 	return NULL;
 }

 static const struct dvb_frontend_ops tda10021_ops = {
 	.delsys = { SYS_DVBC_ANNEX_A, SYS_DVBC_ANNEX_C },
 	.info = {
 		.name = "Philips TDA10021 DVB-C",
 		.frequency_min_hz =  47 * MHz,
 		.frequency_max_hz = 862 * MHz,
 		.frequency_stepsize_hz = 62500,
 		.symbol_rate_min = (XIN / 2) / 64,     /* SACLK/64 == (XIN/2)/64 */
 		.symbol_rate_max = (XIN / 2) / 4,      /* SACLK/4 */
 	#if 0
 		.frequency_tolerance = ???,
 		.symbol_rate_tolerance = ???,  /* ppm */  /* == 8% (spec p. 5) */
 	#endif
 		.caps = 0x400 | //FE_CAN_QAM_4
 			FE_CAN_QAM_16 | FE_CAN_QAM_32 | FE_CAN_QAM_64 |
 			FE_CAN_QAM_128 | FE_CAN_QAM_256 |
 			FE_CAN_FEC_AUTO
 	},

 	.release = tda10021_release,

 	.init = tda10021_init,
 	.sleep = tda10021_sleep,
 	.i2c_gate_ctrl = tda10021_i2c_gate_ctrl,

 	.set_frontend = tda10021_set_parameters,
 	.get_frontend = tda10021_get_frontend,

 	.read_status = tda10021_read_status,
 	.read_ber = tda10021_read_ber,
 	.read_signal_strength = tda10021_read_signal_strength,
 	.read_snr = tda10021_read_snr,
 	.read_ucblocks = tda10021_read_ucblocks,
 };

 module_param(verbose, int, 0644);
 MODULE_PARM_DESC(verbose, "print AFC offset after tuning for debugging the PWM setting");

 MODULE_DESCRIPTION("Philips TDA10021 DVB-C demodulator driver");
 MODULE_AUTHOR("Ralph Metzler, Holger Waechtler, Markus Schulz");
 MODULE_LICENSE("GPL");

 EXPORT_SYMBOL_GPL(tda10021_attach);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	TDA10021 - Single Chip Cable Channel Receiver driver module
	used on the Siemens DVB-C cards

	Copyright (C) 1999 Convergence Integrated Media GmbH <ralph@convergence.de>
	Copyright (C) 2004 Markus Schulz <msc@antzsystem.de>
	Support for TDA10021

	*/

	#include <linux/delay.h>
	#include <linux/errno.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/string.h>
	#include <linux/slab.h>

	#include <media/dvb_frontend.h>
	#include "tda1002x.h"


	struct tda10021_state {
	struct i2c_adapter* i2c;
	/* configuration settings */
	const struct tda1002x_config* config;
	struct dvb_frontend frontend;

	u8 pwm;
	u8 reg0;
	};


	#if 0
	#define dprintk(x...) printk(x)
	#else
	#define dprintk(x...)
	#endif

	static int verbose;

	#define XIN 57840000UL

	#define FIN (XIN >> 4)

	static int tda10021_inittab_size = 0x40;
	static u8 tda10021_inittab[0x40]=
	{
	0x73, 0x6a, 0x23, 0x0a, 0x02, 0x37, 0x77, 0x1a,
	0x37, 0x6a, 0x17, 0x8a, 0x1e, 0x86, 0x43, 0x40,
	0xb8, 0x3f, 0xa1, 0x00, 0xcd, 0x01, 0x00, 0xff,
	0x11, 0x00, 0x7c, 0x31, 0x30, 0x20, 0x00, 0x00,
	0x02, 0x00, 0x00, 0x7d, 0x00, 0x00, 0x00, 0x00,
	0x07, 0x00, 0x33, 0x11, 0x0d, 0x95, 0x08, 0x58,
	0x00, 0x00, 0x80, 0x00, 0x80, 0xff, 0x00, 0x00,
	0x04, 0x2d, 0x2f, 0xff, 0x00, 0x00, 0x00, 0x00,
	};

	static int _tda10021_writereg (struct tda10021_state* state, u8 reg, u8 data)
	{
	u8 buf[] = { reg, data };
	struct i2c_msg msg = { .addr = state->config->demod_address, .flags = 0, .buf = buf, .len = 2 };
	int ret;

	ret = i2c_transfer (state->i2c, &msg, 1);
	if (ret != 1)
	printk("DVB: TDA10021(%d): %s, writereg error (reg == 0x%02x, val == 0x%02x, ret == %i)\n",
	state->frontend.dvb->num, __func__, reg, data, ret);

	msleep(10);
	return (ret != 1) ? -EREMOTEIO : 0;
	}

	static u8 tda10021_readreg (struct tda10021_state* state, u8 reg)
	{
	u8 b0 [] = { reg };
	u8 b1 [] = { 0 };
	struct i2c_msg msg [] = { { .addr = state->config->demod_address, .flags = 0, .buf = b0, .len = 1 },
	{ .addr = state->config->demod_address, .flags = I2C_M_RD, .buf = b1, .len = 1 } };
	int ret;

	ret = i2c_transfer (state->i2c, msg, 2);
	// Don't print an error message if the id is read.
	if (ret != 2 && reg != 0x1a)
	printk("DVB: TDA10021: %s: readreg error (ret == %i)\n",
	__func__, ret);
	return b1[0];
	}

	//get access to tuner
	static int lock_tuner(struct tda10021_state* state)
	{
	u8 buf[2] = { 0x0f, tda10021_inittab[0x0f] \| 0x80 };
	struct i2c_msg msg = {.addr=state->config->demod_address, .flags=0, .buf=buf, .len=2};

	if(i2c_transfer(state->i2c, &msg, 1) != 1)
	{
	printk("tda10021: lock tuner fails\n");
	return -EREMOTEIO;
	}
	return 0;
	}

	//release access from tuner
	static int unlock_tuner(struct tda10021_state* state)
	{
	u8 buf[2] = { 0x0f, tda10021_inittab[0x0f] & 0x7f };
	struct i2c_msg msg_post={.addr=state->config->demod_address, .flags=0, .buf=buf, .len=2};

	if(i2c_transfer(state->i2c, &msg_post, 1) != 1)
	{
	printk("tda10021: unlock tuner fails\n");
	return -EREMOTEIO;
	}
	return 0;
	}

	static int tda10021_setup_reg0(struct tda10021_state *state, u8 reg0,
	enum fe_spectral_inversion inversion)
	{
	reg0 \|= state->reg0 & 0x63;

	if ((INVERSION_ON == inversion) ^ (state->config->invert == 0))
	reg0 &= ~0x20;
	else
	reg0 \|= 0x20;

	_tda10021_writereg (state, 0x00, reg0 & 0xfe);
	_tda10021_writereg (state, 0x00, reg0 \| 0x01);

	state->reg0 = reg0;
	return 0;
	}

	static int tda10021_set_symbolrate (struct tda10021_state* state, u32 symbolrate)
	{
	s32 BDR;
	s32 BDRI;
	s16 SFIL = 0;
	u16 NDEC = 0;
	u32 tmp, ratio;

	if (symbolrate > XIN / 2)
	symbolrate = XIN / 2;
	else if (symbolrate < 500000)
	symbolrate = 500000;

	if (symbolrate < XIN / 16)
	NDEC = 1;
	if (symbolrate < XIN / 32)
	NDEC = 2;
	if (symbolrate < XIN / 64)
	NDEC = 3;

	if (symbolrate < XIN * 10 / 123)
	SFIL = 1;
	if (symbolrate < XIN * 10 / 160)
	SFIL = 0;
	if (symbolrate < XIN * 10 / 246)
	SFIL = 1;
	if (symbolrate < XIN * 10 / 320)
	SFIL = 0;
	if (symbolrate < XIN * 10 / 492)
	SFIL = 1;
	if (symbolrate < XIN * 10 / 640)
	SFIL = 0;
	if (symbolrate < XIN * 10 / 984)
	SFIL = 1;

	symbolrate <<= NDEC;
	ratio = (symbolrate << 4) / FIN;
	tmp = ((symbolrate << 4) % FIN) << 8;
	ratio = (ratio << 8) + tmp / FIN;
	tmp = (tmp % FIN) << 8;
	ratio = (ratio << 8) + DIV_ROUND_CLOSEST(tmp, FIN);

	BDR = ratio;
	BDRI = (((XIN << 5) / symbolrate) + 1) / 2;

	if (BDRI > 0xFF)
	BDRI = 0xFF;

	SFIL = (SFIL << 4) \| tda10021_inittab[0x0E];

	NDEC = (NDEC << 6) \| tda10021_inittab[0x03];

	_tda10021_writereg (state, 0x03, NDEC);
	_tda10021_writereg (state, 0x0a, BDR&0xff);
	_tda10021_writereg (state, 0x0b, (BDR>> 8)&0xff);
	_tda10021_writereg (state, 0x0c, (BDR>>16)&0x3f);

	_tda10021_writereg (state, 0x0d, BDRI);
	_tda10021_writereg (state, 0x0e, SFIL);

	return 0;
	}

	static int tda10021_init (struct dvb_frontend *fe)
	{
	struct tda10021_state* state = fe->demodulator_priv;
	int i;

	dprintk("DVB: TDA10021(%d): init chip\n", fe->adapter->num);

	//_tda10021_writereg (fe, 0, 0);

	for (i=0; i<tda10021_inittab_size; i++)
	_tda10021_writereg (state, i, tda10021_inittab[i]);

	_tda10021_writereg (state, 0x34, state->pwm);

	//Comment by markus
	//0x2A[3-0] == PDIV -> P multiplaying factor (P=PDIV+1)(default 0)
	//0x2A[4] == BYPPLL -> Power down mode (default 1)
	//0x2A[5] == LCK -> PLL Lock Flag
	//0x2A[6] == POLAXIN -> Polarity of the input reference clock (default 0)

	//Activate PLL
	_tda10021_writereg(state, 0x2a, tda10021_inittab[0x2a] & 0xef);
	return 0;
	}

	struct qam_params {
	u8 conf, agcref, lthr, mseth, aref;
	};

	static int tda10021_set_parameters(struct dvb_frontend *fe)
	{
	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
	u32 delsys = c->delivery_system;
	unsigned qam = c->modulation;
	bool is_annex_c;
	u32 reg0x3d;
	struct tda10021_state* state = fe->demodulator_priv;
	static const struct qam_params qam_params[] = {
	/* Modulation Conf AGCref LTHR MSETH AREF */
	[QPSK] = { 0x14, 0x78, 0x78, 0x8c, 0x96 },
	[QAM_16] = { 0x00, 0x8c, 0x87, 0xa2, 0x91 },
	[QAM_32] = { 0x04, 0x8c, 0x64, 0x74, 0x96 },
	[QAM_64] = { 0x08, 0x6a, 0x46, 0x43, 0x6a },
	[QAM_128] = { 0x0c, 0x78, 0x36, 0x34, 0x7e },
	[QAM_256] = { 0x10, 0x5c, 0x26, 0x23, 0x6b },
	};

	switch (delsys) {
	case SYS_DVBC_ANNEX_A:
	is_annex_c = false;
	break;
	case SYS_DVBC_ANNEX_C:
	is_annex_c = true;
	break;
	default:
	return -EINVAL;
	}

	/*
	* gcc optimizes the code below the same way as it would code:
	* "if (qam > 5) return -EINVAL;"
	* Yet, the code is clearer, as it shows what QAM standards are
	* supported by the driver, and avoids the usage of magic numbers on
	* it.
	*/
	switch (qam) {
	case QPSK:
	case QAM_16:
	case QAM_32:
	case QAM_64:
	case QAM_128:
	case QAM_256:
	break;
	default:
	return -EINVAL;
	}

	if (c->inversion != INVERSION_ON && c->inversion != INVERSION_OFF)
	return -EINVAL;

	/printk("tda10021: set frequency to %d qam=%d symrate=%d\n", p->frequency,qam,p->symbol_rate);/

	if (fe->ops.tuner_ops.set_params) {
	fe->ops.tuner_ops.set_params(fe);
	if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
	}

	tda10021_set_symbolrate(state, c->symbol_rate);
	_tda10021_writereg(state, 0x34, state->pwm);

	_tda10021_writereg(state, 0x01, qam_params[qam].agcref);
	_tda10021_writereg(state, 0x05, qam_params[qam].lthr);
	_tda10021_writereg(state, 0x08, qam_params[qam].mseth);
	_tda10021_writereg(state, 0x09, qam_params[qam].aref);

	/*
	* Bit 0 == 0 means roll-off = 0.15 (Annex A)
	* == 1 means roll-off = 0.13 (Annex C)
	*/
	reg0x3d = tda10021_readreg (state, 0x3d);
	if (is_annex_c)
	_tda10021_writereg (state, 0x3d, 0x01 \| reg0x3d);
	else
	_tda10021_writereg (state, 0x3d, 0xfe & reg0x3d);
	tda10021_setup_reg0(state, qam_params[qam].conf, c->inversion);

	return 0;
	}

	static int tda10021_read_status(struct dvb_frontend *fe,
	enum fe_status *status)
	{
	struct tda10021_state* state = fe->demodulator_priv;
	int sync;

	*status = 0;
	//0x11[0] == EQALGO -> Equalizer algorithms state
	//0x11[1] == CARLOCK -> Carrier locked
	//0x11[2] == FSYNC -> Frame synchronisation
	//0x11[3] == FEL -> Front End locked
	//0x11[6] == NODVB -> DVB Mode Information
	sync = tda10021_readreg (state, 0x11);

	if (sync & 2)
	*status \|= FE_HAS_SIGNAL\|FE_HAS_CARRIER;

	if (sync & 4)
	*status \|= FE_HAS_SYNC\|FE_HAS_VITERBI;

	if (sync & 8)
	*status \|= FE_HAS_LOCK;

	return 0;
	}

	static int tda10021_read_ber(struct dvb_frontend* fe, u32* ber)
	{
	struct tda10021_state* state = fe->demodulator_priv;

	u32 _ber = tda10021_readreg(state, 0x14) \|
	(tda10021_readreg(state, 0x15) << 8) \|
	((tda10021_readreg(state, 0x16) & 0x0f) << 16);
	_tda10021_writereg(state, 0x10, (tda10021_readreg(state, 0x10) & ~0xc0)
	\| (tda10021_inittab[0x10] & 0xc0));
	ber = 10 _ber;

	return 0;
	}

	static int tda10021_read_signal_strength(struct dvb_frontend* fe, u16* strength)
	{
	struct tda10021_state* state = fe->demodulator_priv;

	u8 config = tda10021_readreg(state, 0x02);
	u8 gain = tda10021_readreg(state, 0x17);
	if (config & 0x02)
	/* the agc value is inverted */
	gain = ~gain;
	*strength = (gain << 8) \| gain;

	return 0;
	}

	static int tda10021_read_snr(struct dvb_frontend* fe, u16* snr)
	{
	struct tda10021_state* state = fe->demodulator_priv;

	u8 quality = ~tda10021_readreg(state, 0x18);
	*snr = (quality << 8) \| quality;

	return 0;
	}

	static int tda10021_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
	{
	struct tda10021_state* state = fe->demodulator_priv;

	*ucblocks = tda10021_readreg (state, 0x13) & 0x7f;
	if (*ucblocks == 0x7f)
	*ucblocks = 0xffffffff;

	/* reset uncorrected block counter */
	_tda10021_writereg (state, 0x10, tda10021_inittab[0x10] & 0xdf);
	_tda10021_writereg (state, 0x10, tda10021_inittab[0x10]);

	return 0;
	}

	static int tda10021_get_frontend(struct dvb_frontend *fe,
	struct dtv_frontend_properties *p)
	{
	struct tda10021_state* state = fe->demodulator_priv;
	int sync;
	s8 afc = 0;

	sync = tda10021_readreg(state, 0x11);
	afc = tda10021_readreg(state, 0x19);
	if (verbose) {
	/* AFC only valid when carrier has been recovered */
	printk(sync & 2 ? "DVB: TDA10021(%d): AFC (%d) %dHz\n" :
	"DVB: TDA10021(%d): [AFC (%d) %dHz]\n",
	state->frontend.dvb->num, afc,
	-((s32)p->symbol_rate * afc) >> 10);
	}

	p->inversion = ((state->reg0 & 0x20) == 0x20) ^ (state->config->invert != 0) ? INVERSION_ON : INVERSION_OFF;
	p->modulation = ((state->reg0 >> 2) & 7) + QAM_16;

	p->fec_inner = FEC_NONE;
	p->frequency = ((p->frequency + 31250) / 62500) * 62500;

	if (sync & 2)
	p->frequency -= ((s32)p->symbol_rate * afc) >> 10;

	return 0;
	}

	static int tda10021_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
	{
	struct tda10021_state* state = fe->demodulator_priv;

	if (enable) {
	lock_tuner(state);
	} else {
	unlock_tuner(state);
	}
	return 0;
	}

	static int tda10021_sleep(struct dvb_frontend* fe)
	{
	struct tda10021_state* state = fe->demodulator_priv;

	_tda10021_writereg (state, 0x1b, 0x02); /* pdown ADC */
	_tda10021_writereg (state, 0x00, 0x80); /* standby */

	return 0;
	}

	static void tda10021_release(struct dvb_frontend* fe)
	{
	struct tda10021_state* state = fe->demodulator_priv;
	kfree(state);
	}

	static const struct dvb_frontend_ops tda10021_ops;

	struct dvb_frontend* tda10021_attach(const struct tda1002x_config* config,
	struct i2c_adapter* i2c,
	u8 pwm)
	{
	struct tda10021_state* state = NULL;
	u8 id;

	/* allocate memory for the internal state */
	state = kzalloc(sizeof(struct tda10021_state), GFP_KERNEL);
	if (state == NULL) goto error;

	/* setup the state */
	state->config = config;
	state->i2c = i2c;
	state->pwm = pwm;
	state->reg0 = tda10021_inittab[0];

	/* check if the demod is there */
	id = tda10021_readreg(state, 0x1a);
	if ((id & 0xf0) != 0x70) goto error;

	/* Don't claim TDA10023 */
	if (id == 0x7d)
	goto error;

	printk("TDA10021: i2c-addr = 0x%02x, id = 0x%02x\n",
	state->config->demod_address, id);

	/* create dvb_frontend */
	memcpy(&state->frontend.ops, &tda10021_ops, sizeof(struct dvb_frontend_ops));
	state->frontend.demodulator_priv = state;
	return &state->frontend;

	error:
	kfree(state);
	return NULL;
	}

	static const struct dvb_frontend_ops tda10021_ops = {
	.delsys = { SYS_DVBC_ANNEX_A, SYS_DVBC_ANNEX_C },
	.info = {
	.name = "Philips TDA10021 DVB-C",
	.frequency_min_hz = 47 * MHz,
	.frequency_max_hz = 862 * MHz,
	.frequency_stepsize_hz = 62500,
	.symbol_rate_min = (XIN / 2) / 64, /* SACLK/64 == (XIN/2)/64 */
	.symbol_rate_max = (XIN / 2) / 4, /* SACLK/4 */
	#if 0
	.frequency_tolerance = ???,
	.symbol_rate_tolerance = ???, /* ppm / / == 8% (spec p. 5) */
	#endif
	.caps = 0x400 \| //FE_CAN_QAM_4
	FE_CAN_QAM_16 \| FE_CAN_QAM_32 \| FE_CAN_QAM_64 \|
	FE_CAN_QAM_128 \| FE_CAN_QAM_256 \|
	FE_CAN_FEC_AUTO
	},

	.release = tda10021_release,

	.init = tda10021_init,
	.sleep = tda10021_sleep,
	.i2c_gate_ctrl = tda10021_i2c_gate_ctrl,

	.set_frontend = tda10021_set_parameters,
	.get_frontend = tda10021_get_frontend,

	.read_status = tda10021_read_status,
	.read_ber = tda10021_read_ber,
	.read_signal_strength = tda10021_read_signal_strength,
	.read_snr = tda10021_read_snr,
	.read_ucblocks = tda10021_read_ucblocks,
	};

	module_param(verbose, int, 0644);
	MODULE_PARM_DESC(verbose, "print AFC offset after tuning for debugging the PWM setting");

	MODULE_DESCRIPTION("Philips TDA10021 DVB-C demodulator driver");
	MODULE_AUTHOR("Ralph Metzler, Holger Waechtler, Markus Schulz");
	MODULE_LICENSE("GPL");

	EXPORT_SYMBOL_GPL(tda10021_attach);