drivers/media/dvb-frontends/stv0297.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
     Driver for STV0297 demodulator

     Copyright (C) 2004 Andrew de Quincey <adq_dvb@lidskialf.net>
     Copyright (C) 2003-2004 Dennis Noermann <dennis.noermann@noernet.de>

 */

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

 #include <media/dvb_frontend.h>
 #include "stv0297.h"

 struct stv0297_state {
 	struct i2c_adapter *i2c;
 	const struct stv0297_config *config;
 	struct dvb_frontend frontend;

 	unsigned long last_ber;
 	unsigned long base_freq;
 };

 #if 1
 #define dprintk(x...) printk(x)
 #else
 #define dprintk(x...)
 #endif

 #define STV0297_CLOCK_KHZ   28900


 static int stv0297_writereg(struct stv0297_state *state, u8 reg, u8 data)
 {
 	int ret;
 	u8 buf[] = { reg, data };
 	struct i2c_msg msg = {.addr = state->config->demod_address,.flags = 0,.buf = buf,.len = 2 };

 	ret = i2c_transfer(state->i2c, &msg, 1);

 	if (ret != 1)
 		dprintk("%s: writereg error (reg == 0x%02x, val == 0x%02x, ret == %i)\n",
 			__func__, reg, data, ret);

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

 static int stv0297_readreg(struct stv0297_state *state, u8 reg)
 {
 	int ret;
 	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}
 			       };

 	// this device needs a STOP between the register and data
 	if (state->config->stop_during_read) {
 		if ((ret = i2c_transfer(state->i2c, &msg[0], 1)) != 1) {
 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg, ret);
 			return -1;
 		}
 		if ((ret = i2c_transfer(state->i2c, &msg[1], 1)) != 1) {
 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg, ret);
 			return -1;
 		}
 	} else {
 		if ((ret = i2c_transfer(state->i2c, msg, 2)) != 2) {
 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg, ret);
 			return -1;
 		}
 	}

 	return b1[0];
 }

 static int stv0297_writereg_mask(struct stv0297_state *state, u8 reg, u8 mask, u8 data)
 {
 	int val;

 	val = stv0297_readreg(state, reg);
 	val &= ~mask;
 	val |= (data & mask);
 	stv0297_writereg(state, reg, val);

 	return 0;
 }

 static int stv0297_readregs(struct stv0297_state *state, u8 reg1, u8 * b, u8 len)
 {
 	int ret;
 	struct i2c_msg msg[] = { {.addr = state->config->demod_address,.flags = 0,.buf =
 				  &reg1,.len = 1},
 	{.addr = state->config->demod_address,.flags = I2C_M_RD,.buf = b,.len = len}
 	};

 	// this device needs a STOP between the register and data
 	if (state->config->stop_during_read) {
 		if ((ret = i2c_transfer(state->i2c, &msg[0], 1)) != 1) {
 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg1, ret);
 			return -1;
 		}
 		if ((ret = i2c_transfer(state->i2c, &msg[1], 1)) != 1) {
 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg1, ret);
 			return -1;
 		}
 	} else {
 		if ((ret = i2c_transfer(state->i2c, msg, 2)) != 2) {
 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg1, ret);
 			return -1;
 		}
 	}

 	return 0;
 }

 static u32 stv0297_get_symbolrate(struct stv0297_state *state)
 {
 	u64 tmp;

 	tmp = (u64)(stv0297_readreg(state, 0x55)
 		    | (stv0297_readreg(state, 0x56) << 8)
 		    | (stv0297_readreg(state, 0x57) << 16)
 		    | (stv0297_readreg(state, 0x58) << 24));

 	tmp *= STV0297_CLOCK_KHZ;
 	tmp >>= 32;

 	return (u32) tmp;
 }

 static void stv0297_set_symbolrate(struct stv0297_state *state, u32 srate)
 {
 	long tmp;

 	tmp = 131072L * srate;	/* 131072 = 2^17  */
 	tmp = tmp / (STV0297_CLOCK_KHZ / 4);	/* 1/4 = 2^-2 */
 	tmp = tmp * 8192L;	/* 8192 = 2^13 */

 	stv0297_writereg(state, 0x55, (unsigned char) (tmp & 0xFF));
 	stv0297_writereg(state, 0x56, (unsigned char) (tmp >> 8));
 	stv0297_writereg(state, 0x57, (unsigned char) (tmp >> 16));
 	stv0297_writereg(state, 0x58, (unsigned char) (tmp >> 24));
 }

 static void stv0297_set_sweeprate(struct stv0297_state *state, short fshift, long symrate)
 {
 	long tmp;

 	tmp = (long) fshift *262144L;	/* 262144 = 2*18 */
 	tmp /= symrate;
 	tmp *= 1024;		/* 1024 = 2*10   */

 	// adjust
 	if (tmp >= 0) {
 		tmp += 500000;
 	} else {
 		tmp -= 500000;
 	}
 	tmp /= 1000000;

 	stv0297_writereg(state, 0x60, tmp & 0xFF);
 	stv0297_writereg_mask(state, 0x69, 0xF0, (tmp >> 4) & 0xf0);
 }

 static void stv0297_set_carrieroffset(struct stv0297_state *state, long offset)
 {
 	long tmp;

 	/* symrate is hardcoded to 10000 */
 	tmp = offset * 26844L;	/* (2**28)/10000 */
 	if (tmp < 0)
 		tmp += 0x10000000;
 	tmp &= 0x0FFFFFFF;

 	stv0297_writereg(state, 0x66, (unsigned char) (tmp & 0xFF));
 	stv0297_writereg(state, 0x67, (unsigned char) (tmp >> 8));
 	stv0297_writereg(state, 0x68, (unsigned char) (tmp >> 16));
 	stv0297_writereg_mask(state, 0x69, 0x0F, (tmp >> 24) & 0x0f);
 }

 /*
 static long stv0297_get_carrieroffset(struct stv0297_state *state)
 {
 	s64 tmp;

 	stv0297_writereg(state, 0x6B, 0x00);

 	tmp = stv0297_readreg(state, 0x66);
 	tmp |= (stv0297_readreg(state, 0x67) << 8);
 	tmp |= (stv0297_readreg(state, 0x68) << 16);
 	tmp |= (stv0297_readreg(state, 0x69) & 0x0F) << 24;

 	tmp *= stv0297_get_symbolrate(state);
 	tmp >>= 28;

 	return (s32) tmp;
 }
 */

 static void stv0297_set_initialdemodfreq(struct stv0297_state *state, long freq)
 {
 	s32 tmp;

 	if (freq > 10000)
 		freq -= STV0297_CLOCK_KHZ;

 	tmp = (STV0297_CLOCK_KHZ * 1000) / (1 << 16);
 	tmp = (freq * 1000) / tmp;
 	if (tmp > 0xffff)
 		tmp = 0xffff;

 	stv0297_writereg_mask(state, 0x25, 0x80, 0x80);
 	stv0297_writereg(state, 0x21, tmp >> 8);
 	stv0297_writereg(state, 0x20, tmp);
 }

 static int stv0297_set_qam(struct stv0297_state *state,
 			   enum fe_modulation modulation)
 {
 	int val = 0;

 	switch (modulation) {
 	case QAM_16:
 		val = 0;
 		break;

 	case QAM_32:
 		val = 1;
 		break;

 	case QAM_64:
 		val = 4;
 		break;

 	case QAM_128:
 		val = 2;
 		break;

 	case QAM_256:
 		val = 3;
 		break;

 	default:
 		return -EINVAL;
 	}

 	stv0297_writereg_mask(state, 0x00, 0x70, val << 4);

 	return 0;
 }

 static int stv0297_set_inversion(struct stv0297_state *state,
 				 enum fe_spectral_inversion inversion)
 {
 	int val = 0;

 	switch (inversion) {
 	case INVERSION_OFF:
 		val = 0;
 		break;

 	case INVERSION_ON:
 		val = 1;
 		break;

 	default:
 		return -EINVAL;
 	}

 	stv0297_writereg_mask(state, 0x83, 0x08, val << 3);

 	return 0;
 }

 static int stv0297_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
 {
 	struct stv0297_state *state = fe->demodulator_priv;

 	if (enable) {
 		stv0297_writereg(state, 0x87, 0x78);
 		stv0297_writereg(state, 0x86, 0xc8);
 	}

 	return 0;
 }

 static int stv0297_init(struct dvb_frontend *fe)
 {
 	struct stv0297_state *state = fe->demodulator_priv;
 	int i;

 	/* load init table */
 	for (i=0; !(state->config->inittab[i] == 0xff && state->config->inittab[i+1] == 0xff); i+=2)
 		stv0297_writereg(state, state->config->inittab[i], state->config->inittab[i+1]);
 	msleep(200);

 	state->last_ber = 0;

 	return 0;
 }

 static int stv0297_sleep(struct dvb_frontend *fe)
 {
 	struct stv0297_state *state = fe->demodulator_priv;

 	stv0297_writereg_mask(state, 0x80, 1, 1);

 	return 0;
 }

 static int stv0297_read_status(struct dvb_frontend *fe,
 			       enum fe_status *status)
 {
 	struct stv0297_state *state = fe->demodulator_priv;

 	u8 sync = stv0297_readreg(state, 0xDF);

 	*status = 0;
 	if (sync & 0x80)
 		*status |=
 			FE_HAS_SYNC | FE_HAS_SIGNAL | FE_HAS_CARRIER | FE_HAS_VITERBI | FE_HAS_LOCK;
 	return 0;
 }

 static int stv0297_read_ber(struct dvb_frontend *fe, u32 * ber)
 {
 	struct stv0297_state *state = fe->demodulator_priv;
 	u8 BER[3];

 	stv0297_readregs(state, 0xA0, BER, 3);
 	if (!(BER[0] & 0x80)) {
 		state->last_ber = BER[2] << 8 | BER[1];
 		stv0297_writereg_mask(state, 0xA0, 0x80, 0x80);
 	}

 	*ber = state->last_ber;

 	return 0;
 }


 static int stv0297_read_signal_strength(struct dvb_frontend *fe, u16 * strength)
 {
 	struct stv0297_state *state = fe->demodulator_priv;
 	u8 STRENGTH[3];
 	u16 tmp;

 	stv0297_readregs(state, 0x41, STRENGTH, 3);
 	tmp = (STRENGTH[1] & 0x03) << 8 | STRENGTH[0];
 	if (STRENGTH[2] & 0x20) {
 		if (tmp < 0x200)
 			tmp = 0;
 		else
 			tmp = tmp - 0x200;
 	} else {
 		if (tmp > 0x1ff)
 			tmp = 0;
 		else
 			tmp = 0x1ff - tmp;
 	}
 	*strength = (tmp << 7) | (tmp >> 2);
 	return 0;
 }

 static int stv0297_read_snr(struct dvb_frontend *fe, u16 * snr)
 {
 	struct stv0297_state *state = fe->demodulator_priv;
 	u8 SNR[2];

 	stv0297_readregs(state, 0x07, SNR, 2);
 	*snr = SNR[1] << 8 | SNR[0];

 	return 0;
 }

 static int stv0297_read_ucblocks(struct dvb_frontend *fe, u32 * ucblocks)
 {
 	struct stv0297_state *state = fe->demodulator_priv;

 	stv0297_writereg_mask(state, 0xDF, 0x03, 0x03); /* freeze the counters */

 	*ucblocks = (stv0297_readreg(state, 0xD5) << 8)
 		| stv0297_readreg(state, 0xD4);

 	stv0297_writereg_mask(state, 0xDF, 0x03, 0x02); /* clear the counters */
 	stv0297_writereg_mask(state, 0xDF, 0x03, 0x01); /* re-enable the counters */

 	return 0;
 }

 static int stv0297_set_frontend(struct dvb_frontend *fe)
 {
 	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
 	struct stv0297_state *state = fe->demodulator_priv;
 	int u_threshold;
 	int initial_u;
 	int blind_u;
 	int delay;
 	int sweeprate;
 	int carrieroffset;
 	unsigned long timeout;
 	enum fe_spectral_inversion inversion;

 	switch (p->modulation) {
 	case QAM_16:
 	case QAM_32:
 	case QAM_64:
 		delay = 100;
 		sweeprate = 1000;
 		break;

 	case QAM_128:
 	case QAM_256:
 		delay = 200;
 		sweeprate = 500;
 		break;

 	default:
 		return -EINVAL;
 	}

 	// determine inversion dependent parameters
 	inversion = p->inversion;
 	if (state->config->invert)
 		inversion = (inversion == INVERSION_ON) ? INVERSION_OFF : INVERSION_ON;
 	carrieroffset = -330;
 	switch (inversion) {
 	case INVERSION_OFF:
 		break;

 	case INVERSION_ON:
 		sweeprate = -sweeprate;
 		carrieroffset = -carrieroffset;
 		break;

 	default:
 		return -EINVAL;
 	}

 	stv0297_init(fe);
 	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);
 	}

 	/* clear software interrupts */
 	stv0297_writereg(state, 0x82, 0x0);

 	/* set initial demodulation frequency */
 	stv0297_set_initialdemodfreq(state, 7250);

 	/* setup AGC */
 	stv0297_writereg_mask(state, 0x43, 0x10, 0x00);
 	stv0297_writereg(state, 0x41, 0x00);
 	stv0297_writereg_mask(state, 0x42, 0x03, 0x01);
 	stv0297_writereg_mask(state, 0x36, 0x60, 0x00);
 	stv0297_writereg_mask(state, 0x36, 0x18, 0x00);
 	stv0297_writereg_mask(state, 0x71, 0x80, 0x80);
 	stv0297_writereg(state, 0x72, 0x00);
 	stv0297_writereg(state, 0x73, 0x00);
 	stv0297_writereg_mask(state, 0x74, 0x0F, 0x00);
 	stv0297_writereg_mask(state, 0x43, 0x08, 0x00);
 	stv0297_writereg_mask(state, 0x71, 0x80, 0x00);

 	/* setup STL */
 	stv0297_writereg_mask(state, 0x5a, 0x20, 0x20);
 	stv0297_writereg_mask(state, 0x5b, 0x02, 0x02);
 	stv0297_writereg_mask(state, 0x5b, 0x02, 0x00);
 	stv0297_writereg_mask(state, 0x5b, 0x01, 0x00);
 	stv0297_writereg_mask(state, 0x5a, 0x40, 0x40);

 	/* disable frequency sweep */
 	stv0297_writereg_mask(state, 0x6a, 0x01, 0x00);

 	/* reset deinterleaver */
 	stv0297_writereg_mask(state, 0x81, 0x01, 0x01);
 	stv0297_writereg_mask(state, 0x81, 0x01, 0x00);

 	/* ??? */
 	stv0297_writereg_mask(state, 0x83, 0x20, 0x20);
 	stv0297_writereg_mask(state, 0x83, 0x20, 0x00);

 	/* reset equaliser */
 	u_threshold = stv0297_readreg(state, 0x00) & 0xf;
 	initial_u = stv0297_readreg(state, 0x01) >> 4;
 	blind_u = stv0297_readreg(state, 0x01) & 0xf;
 	stv0297_writereg_mask(state, 0x84, 0x01, 0x01);
 	stv0297_writereg_mask(state, 0x84, 0x01, 0x00);
 	stv0297_writereg_mask(state, 0x00, 0x0f, u_threshold);
 	stv0297_writereg_mask(state, 0x01, 0xf0, initial_u << 4);
 	stv0297_writereg_mask(state, 0x01, 0x0f, blind_u);

 	/* data comes from internal A/D */
 	stv0297_writereg_mask(state, 0x87, 0x80, 0x00);

 	/* clear phase registers */
 	stv0297_writereg(state, 0x63, 0x00);
 	stv0297_writereg(state, 0x64, 0x00);
 	stv0297_writereg(state, 0x65, 0x00);
 	stv0297_writereg(state, 0x66, 0x00);
 	stv0297_writereg(state, 0x67, 0x00);
 	stv0297_writereg(state, 0x68, 0x00);
 	stv0297_writereg_mask(state, 0x69, 0x0f, 0x00);

 	/* set parameters */
 	stv0297_set_qam(state, p->modulation);
 	stv0297_set_symbolrate(state, p->symbol_rate / 1000);
 	stv0297_set_sweeprate(state, sweeprate, p->symbol_rate / 1000);
 	stv0297_set_carrieroffset(state, carrieroffset);
 	stv0297_set_inversion(state, inversion);

 	/* kick off lock */
 	/* Disable corner detection for higher QAMs */
 	if (p->modulation == QAM_128 ||
 		p->modulation == QAM_256)
 		stv0297_writereg_mask(state, 0x88, 0x08, 0x00);
 	else
 		stv0297_writereg_mask(state, 0x88, 0x08, 0x08);

 	stv0297_writereg_mask(state, 0x5a, 0x20, 0x00);
 	stv0297_writereg_mask(state, 0x6a, 0x01, 0x01);
 	stv0297_writereg_mask(state, 0x43, 0x40, 0x40);
 	stv0297_writereg_mask(state, 0x5b, 0x30, 0x00);
 	stv0297_writereg_mask(state, 0x03, 0x0c, 0x0c);
 	stv0297_writereg_mask(state, 0x03, 0x03, 0x03);
 	stv0297_writereg_mask(state, 0x43, 0x10, 0x10);

 	/* wait for WGAGC lock */
 	timeout = jiffies + msecs_to_jiffies(2000);
 	while (time_before(jiffies, timeout)) {
 		msleep(10);
 		if (stv0297_readreg(state, 0x43) & 0x08)
 			break;
 	}
 	if (time_after(jiffies, timeout)) {
 		goto timeout;
 	}
 	msleep(20);

 	/* wait for equaliser partial convergence */
 	timeout = jiffies + msecs_to_jiffies(500);
 	while (time_before(jiffies, timeout)) {
 		msleep(10);

 		if (stv0297_readreg(state, 0x82) & 0x04) {
 			break;
 		}
 	}
 	if (time_after(jiffies, timeout)) {
 		goto timeout;
 	}

 	/* wait for equaliser full convergence */
 	timeout = jiffies + msecs_to_jiffies(delay);
 	while (time_before(jiffies, timeout)) {
 		msleep(10);

 		if (stv0297_readreg(state, 0x82) & 0x08) {
 			break;
 		}
 	}
 	if (time_after(jiffies, timeout)) {
 		goto timeout;
 	}

 	/* disable sweep */
 	stv0297_writereg_mask(state, 0x6a, 1, 0);
 	stv0297_writereg_mask(state, 0x88, 8, 0);

 	/* wait for main lock */
 	timeout = jiffies + msecs_to_jiffies(20);
 	while (time_before(jiffies, timeout)) {
 		msleep(10);

 		if (stv0297_readreg(state, 0xDF) & 0x80) {
 			break;
 		}
 	}
 	if (time_after(jiffies, timeout)) {
 		goto timeout;
 	}
 	msleep(100);

 	/* is it still locked after that delay? */
 	if (!(stv0297_readreg(state, 0xDF) & 0x80)) {
 		goto timeout;
 	}

 	/* success!! */
 	stv0297_writereg_mask(state, 0x5a, 0x40, 0x00);
 	state->base_freq = p->frequency;
 	return 0;

 timeout:
 	stv0297_writereg_mask(state, 0x6a, 0x01, 0x00);
 	return 0;
 }

 static int stv0297_get_frontend(struct dvb_frontend *fe,
 				struct dtv_frontend_properties *p)
 {
 	struct stv0297_state *state = fe->demodulator_priv;
 	int reg_00, reg_83;

 	reg_00 = stv0297_readreg(state, 0x00);
 	reg_83 = stv0297_readreg(state, 0x83);

 	p->frequency = state->base_freq;
 	p->inversion = (reg_83 & 0x08) ? INVERSION_ON : INVERSION_OFF;
 	if (state->config->invert)
 		p->inversion = (p->inversion == INVERSION_ON) ? INVERSION_OFF : INVERSION_ON;
 	p->symbol_rate = stv0297_get_symbolrate(state) * 1000;
 	p->fec_inner = FEC_NONE;

 	switch ((reg_00 >> 4) & 0x7) {
 	case 0:
 		p->modulation = QAM_16;
 		break;
 	case 1:
 		p->modulation = QAM_32;
 		break;
 	case 2:
 		p->modulation = QAM_128;
 		break;
 	case 3:
 		p->modulation = QAM_256;
 		break;
 	case 4:
 		p->modulation = QAM_64;
 		break;
 	}

 	return 0;
 }

 static void stv0297_release(struct dvb_frontend *fe)
 {
 	struct stv0297_state *state = fe->demodulator_priv;
 	kfree(state);
 }

 static const struct dvb_frontend_ops stv0297_ops;

 struct dvb_frontend *stv0297_attach(const struct stv0297_config *config,
 				    struct i2c_adapter *i2c)
 {
 	struct stv0297_state *state = NULL;

 	/* allocate memory for the internal state */
 	state = kzalloc(sizeof(struct stv0297_state), GFP_KERNEL);
 	if (state == NULL)
 		goto error;

 	/* setup the state */
 	state->config = config;
 	state->i2c = i2c;
 	state->last_ber = 0;
 	state->base_freq = 0;

 	/* check if the demod is there */
 	if ((stv0297_readreg(state, 0x80) & 0x70) != 0x20)
 		goto error;

 	/* create dvb_frontend */
 	memcpy(&state->frontend.ops, &stv0297_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 stv0297_ops = {
 	.delsys = { SYS_DVBC_ANNEX_A },
 	.info = {
 		 .name = "ST STV0297 DVB-C",
 		 .frequency_min_hz = 47 * MHz,
 		 .frequency_max_hz = 862 * MHz,
 		 .frequency_stepsize_hz = 62500,
 		 .symbol_rate_min = 870000,
 		 .symbol_rate_max = 11700000,
 		 .caps = 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 = stv0297_release,

 	.init = stv0297_init,
 	.sleep = stv0297_sleep,
 	.i2c_gate_ctrl = stv0297_i2c_gate_ctrl,

 	.set_frontend = stv0297_set_frontend,
 	.get_frontend = stv0297_get_frontend,

 	.read_status = stv0297_read_status,
 	.read_ber = stv0297_read_ber,
 	.read_signal_strength = stv0297_read_signal_strength,
 	.read_snr = stv0297_read_snr,
 	.read_ucblocks = stv0297_read_ucblocks,
 };

 MODULE_DESCRIPTION("ST STV0297 DVB-C Demodulator driver");
 MODULE_AUTHOR("Dennis Noermann and Andrew de Quincey");
 MODULE_LICENSE("GPL");

 EXPORT_SYMBOL(stv0297_attach);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	Driver for STV0297 demodulator

	Copyright (C) 2004 Andrew de Quincey <adq_dvb@lidskialf.net>
	Copyright (C) 2003-2004 Dennis Noermann <dennis.noermann@noernet.de>

	*/

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

	#include <media/dvb_frontend.h>
	#include "stv0297.h"

	struct stv0297_state {
	struct i2c_adapter *i2c;
	const struct stv0297_config *config;
	struct dvb_frontend frontend;

	unsigned long last_ber;
	unsigned long base_freq;
	};

	#if 1
	#define dprintk(x...) printk(x)
	#else
	#define dprintk(x...)
	#endif

	#define STV0297_CLOCK_KHZ 28900


	static int stv0297_writereg(struct stv0297_state *state, u8 reg, u8 data)
	{
	int ret;
	u8 buf[] = { reg, data };
	struct i2c_msg msg = {.addr = state->config->demod_address,.flags = 0,.buf = buf,.len = 2 };

	ret = i2c_transfer(state->i2c, &msg, 1);

	if (ret != 1)
	dprintk("%s: writereg error (reg == 0x%02x, val == 0x%02x, ret == %i)\n",
	__func__, reg, data, ret);

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

	static int stv0297_readreg(struct stv0297_state *state, u8 reg)
	{
	int ret;
	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}
	};

	// this device needs a STOP between the register and data
	if (state->config->stop_during_read) {
	if ((ret = i2c_transfer(state->i2c, &msg[0], 1)) != 1) {
	dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg, ret);
	return -1;
	}
	if ((ret = i2c_transfer(state->i2c, &msg[1], 1)) != 1) {
	dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg, ret);
	return -1;
	}
	} else {
	if ((ret = i2c_transfer(state->i2c, msg, 2)) != 2) {
	dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg, ret);
	return -1;
	}
	}

	return b1[0];
	}

	static int stv0297_writereg_mask(struct stv0297_state *state, u8 reg, u8 mask, u8 data)
	{
	int val;

	val = stv0297_readreg(state, reg);
	val &= ~mask;
	val \|= (data & mask);
	stv0297_writereg(state, reg, val);

	return 0;
	}

	static int stv0297_readregs(struct stv0297_state state, u8 reg1, u8 b, u8 len)
	{
	int ret;
	struct i2c_msg msg[] = { {.addr = state->config->demod_address,.flags = 0,.buf =
	&reg1,.len = 1},
	{.addr = state->config->demod_address,.flags = I2C_M_RD,.buf = b,.len = len}
	};

	// this device needs a STOP between the register and data
	if (state->config->stop_during_read) {
	if ((ret = i2c_transfer(state->i2c, &msg[0], 1)) != 1) {
	dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg1, ret);
	return -1;
	}
	if ((ret = i2c_transfer(state->i2c, &msg[1], 1)) != 1) {
	dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg1, ret);
	return -1;
	}
	} else {
	if ((ret = i2c_transfer(state->i2c, msg, 2)) != 2) {
	dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg1, ret);
	return -1;
	}
	}

	return 0;
	}

	static u32 stv0297_get_symbolrate(struct stv0297_state *state)
	{
	u64 tmp;

	tmp = (u64)(stv0297_readreg(state, 0x55)
	\| (stv0297_readreg(state, 0x56) << 8)
	\| (stv0297_readreg(state, 0x57) << 16)
	\| (stv0297_readreg(state, 0x58) << 24));

	tmp *= STV0297_CLOCK_KHZ;
	tmp >>= 32;

	return (u32) tmp;
	}

	static void stv0297_set_symbolrate(struct stv0297_state *state, u32 srate)
	{
	long tmp;

	tmp = 131072L * srate; /* 131072 = 2^17 */
	tmp = tmp / (STV0297_CLOCK_KHZ / 4); /* 1/4 = 2^-2 */
	tmp = tmp * 8192L; /* 8192 = 2^13 */

	stv0297_writereg(state, 0x55, (unsigned char) (tmp & 0xFF));
	stv0297_writereg(state, 0x56, (unsigned char) (tmp >> 8));
	stv0297_writereg(state, 0x57, (unsigned char) (tmp >> 16));
	stv0297_writereg(state, 0x58, (unsigned char) (tmp >> 24));
	}

	static void stv0297_set_sweeprate(struct stv0297_state *state, short fshift, long symrate)
	{
	long tmp;

	tmp = (long) fshift 262144L; / 262144 = 218 /
	tmp /= symrate;
	tmp = 1024; / 1024 = 210 /

	// adjust
	if (tmp >= 0) {
	tmp += 500000;
	} else {
	tmp -= 500000;
	}
	tmp /= 1000000;

	stv0297_writereg(state, 0x60, tmp & 0xFF);
	stv0297_writereg_mask(state, 0x69, 0xF0, (tmp >> 4) & 0xf0);
	}

	static void stv0297_set_carrieroffset(struct stv0297_state *state, long offset)
	{
	long tmp;

	/* symrate is hardcoded to 10000 */
	tmp = offset * 26844L; /* (2*28)/10000 /
	if (tmp < 0)
	tmp += 0x10000000;
	tmp &= 0x0FFFFFFF;

	stv0297_writereg(state, 0x66, (unsigned char) (tmp & 0xFF));
	stv0297_writereg(state, 0x67, (unsigned char) (tmp >> 8));
	stv0297_writereg(state, 0x68, (unsigned char) (tmp >> 16));
	stv0297_writereg_mask(state, 0x69, 0x0F, (tmp >> 24) & 0x0f);
	}

	/*
	static long stv0297_get_carrieroffset(struct stv0297_state *state)
	{
	s64 tmp;

	stv0297_writereg(state, 0x6B, 0x00);

	tmp = stv0297_readreg(state, 0x66);
	tmp \|= (stv0297_readreg(state, 0x67) << 8);
	tmp \|= (stv0297_readreg(state, 0x68) << 16);
	tmp \|= (stv0297_readreg(state, 0x69) & 0x0F) << 24;

	tmp *= stv0297_get_symbolrate(state);
	tmp >>= 28;

	return (s32) tmp;
	}
	*/

	static void stv0297_set_initialdemodfreq(struct stv0297_state *state, long freq)
	{
	s32 tmp;

	if (freq > 10000)
	freq -= STV0297_CLOCK_KHZ;

	tmp = (STV0297_CLOCK_KHZ * 1000) / (1 << 16);
	tmp = (freq * 1000) / tmp;
	if (tmp > 0xffff)
	tmp = 0xffff;

	stv0297_writereg_mask(state, 0x25, 0x80, 0x80);
	stv0297_writereg(state, 0x21, tmp >> 8);
	stv0297_writereg(state, 0x20, tmp);
	}

	static int stv0297_set_qam(struct stv0297_state *state,
	enum fe_modulation modulation)
	{
	int val = 0;

	switch (modulation) {
	case QAM_16:
	val = 0;
	break;

	case QAM_32:
	val = 1;
	break;

	case QAM_64:
	val = 4;
	break;

	case QAM_128:
	val = 2;
	break;

	case QAM_256:
	val = 3;
	break;

	default:
	return -EINVAL;
	}

	stv0297_writereg_mask(state, 0x00, 0x70, val << 4);

	return 0;
	}

	static int stv0297_set_inversion(struct stv0297_state *state,
	enum fe_spectral_inversion inversion)
	{
	int val = 0;

	switch (inversion) {
	case INVERSION_OFF:
	val = 0;
	break;

	case INVERSION_ON:
	val = 1;
	break;

	default:
	return -EINVAL;
	}

	stv0297_writereg_mask(state, 0x83, 0x08, val << 3);

	return 0;
	}

	static int stv0297_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
	{
	struct stv0297_state *state = fe->demodulator_priv;

	if (enable) {
	stv0297_writereg(state, 0x87, 0x78);
	stv0297_writereg(state, 0x86, 0xc8);
	}

	return 0;
	}

	static int stv0297_init(struct dvb_frontend *fe)
	{
	struct stv0297_state *state = fe->demodulator_priv;
	int i;

	/* load init table */
	for (i=0; !(state->config->inittab[i] == 0xff && state->config->inittab[i+1] == 0xff); i+=2)
	stv0297_writereg(state, state->config->inittab[i], state->config->inittab[i+1]);
	msleep(200);

	state->last_ber = 0;

	return 0;
	}

	static int stv0297_sleep(struct dvb_frontend *fe)
	{
	struct stv0297_state *state = fe->demodulator_priv;

	stv0297_writereg_mask(state, 0x80, 1, 1);

	return 0;
	}

	static int stv0297_read_status(struct dvb_frontend *fe,
	enum fe_status *status)
	{
	struct stv0297_state *state = fe->demodulator_priv;

	u8 sync = stv0297_readreg(state, 0xDF);

	*status = 0;
	if (sync & 0x80)
	*status \|=
	FE_HAS_SYNC \| FE_HAS_SIGNAL \| FE_HAS_CARRIER \| FE_HAS_VITERBI \| FE_HAS_LOCK;
	return 0;
	}

	static int stv0297_read_ber(struct dvb_frontend fe, u32 ber)
	{
	struct stv0297_state *state = fe->demodulator_priv;
	u8 BER[3];

	stv0297_readregs(state, 0xA0, BER, 3);
	if (!(BER[0] & 0x80)) {
	state->last_ber = BER[2] << 8 \| BER[1];
	stv0297_writereg_mask(state, 0xA0, 0x80, 0x80);
	}

	*ber = state->last_ber;

	return 0;
	}


	static int stv0297_read_signal_strength(struct dvb_frontend fe, u16 strength)
	{
	struct stv0297_state *state = fe->demodulator_priv;
	u8 STRENGTH[3];
	u16 tmp;

	stv0297_readregs(state, 0x41, STRENGTH, 3);
	tmp = (STRENGTH[1] & 0x03) << 8 \| STRENGTH[0];
	if (STRENGTH[2] & 0x20) {
	if (tmp < 0x200)
	tmp = 0;
	else
	tmp = tmp - 0x200;
	} else {
	if (tmp > 0x1ff)
	tmp = 0;
	else
	tmp = 0x1ff - tmp;
	}
	*strength = (tmp << 7) \| (tmp >> 2);
	return 0;
	}

	static int stv0297_read_snr(struct dvb_frontend fe, u16 snr)
	{
	struct stv0297_state *state = fe->demodulator_priv;
	u8 SNR[2];

	stv0297_readregs(state, 0x07, SNR, 2);
	*snr = SNR[1] << 8 \| SNR[0];

	return 0;
	}

	static int stv0297_read_ucblocks(struct dvb_frontend fe, u32 ucblocks)
	{
	struct stv0297_state *state = fe->demodulator_priv;

	stv0297_writereg_mask(state, 0xDF, 0x03, 0x03); /* freeze the counters */

	*ucblocks = (stv0297_readreg(state, 0xD5) << 8)
	\| stv0297_readreg(state, 0xD4);

	stv0297_writereg_mask(state, 0xDF, 0x03, 0x02); /* clear the counters */
	stv0297_writereg_mask(state, 0xDF, 0x03, 0x01); /* re-enable the counters */

	return 0;
	}

	static int stv0297_set_frontend(struct dvb_frontend *fe)
	{
	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
	struct stv0297_state *state = fe->demodulator_priv;
	int u_threshold;
	int initial_u;
	int blind_u;
	int delay;
	int sweeprate;
	int carrieroffset;
	unsigned long timeout;
	enum fe_spectral_inversion inversion;

	switch (p->modulation) {
	case QAM_16:
	case QAM_32:
	case QAM_64:
	delay = 100;
	sweeprate = 1000;
	break;

	case QAM_128:
	case QAM_256:
	delay = 200;
	sweeprate = 500;
	break;

	default:
	return -EINVAL;
	}

	// determine inversion dependent parameters
	inversion = p->inversion;
	if (state->config->invert)
	inversion = (inversion == INVERSION_ON) ? INVERSION_OFF : INVERSION_ON;
	carrieroffset = -330;
	switch (inversion) {
	case INVERSION_OFF:
	break;

	case INVERSION_ON:
	sweeprate = -sweeprate;
	carrieroffset = -carrieroffset;
	break;

	default:
	return -EINVAL;
	}

	stv0297_init(fe);
	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);
	}

	/* clear software interrupts */
	stv0297_writereg(state, 0x82, 0x0);

	/* set initial demodulation frequency */
	stv0297_set_initialdemodfreq(state, 7250);

	/* setup AGC */
	stv0297_writereg_mask(state, 0x43, 0x10, 0x00);
	stv0297_writereg(state, 0x41, 0x00);
	stv0297_writereg_mask(state, 0x42, 0x03, 0x01);
	stv0297_writereg_mask(state, 0x36, 0x60, 0x00);
	stv0297_writereg_mask(state, 0x36, 0x18, 0x00);
	stv0297_writereg_mask(state, 0x71, 0x80, 0x80);
	stv0297_writereg(state, 0x72, 0x00);
	stv0297_writereg(state, 0x73, 0x00);
	stv0297_writereg_mask(state, 0x74, 0x0F, 0x00);
	stv0297_writereg_mask(state, 0x43, 0x08, 0x00);
	stv0297_writereg_mask(state, 0x71, 0x80, 0x00);

	/* setup STL */
	stv0297_writereg_mask(state, 0x5a, 0x20, 0x20);
	stv0297_writereg_mask(state, 0x5b, 0x02, 0x02);
	stv0297_writereg_mask(state, 0x5b, 0x02, 0x00);
	stv0297_writereg_mask(state, 0x5b, 0x01, 0x00);
	stv0297_writereg_mask(state, 0x5a, 0x40, 0x40);

	/* disable frequency sweep */
	stv0297_writereg_mask(state, 0x6a, 0x01, 0x00);

	/* reset deinterleaver */
	stv0297_writereg_mask(state, 0x81, 0x01, 0x01);
	stv0297_writereg_mask(state, 0x81, 0x01, 0x00);

	/* ??? */
	stv0297_writereg_mask(state, 0x83, 0x20, 0x20);
	stv0297_writereg_mask(state, 0x83, 0x20, 0x00);

	/* reset equaliser */
	u_threshold = stv0297_readreg(state, 0x00) & 0xf;
	initial_u = stv0297_readreg(state, 0x01) >> 4;
	blind_u = stv0297_readreg(state, 0x01) & 0xf;
	stv0297_writereg_mask(state, 0x84, 0x01, 0x01);
	stv0297_writereg_mask(state, 0x84, 0x01, 0x00);
	stv0297_writereg_mask(state, 0x00, 0x0f, u_threshold);
	stv0297_writereg_mask(state, 0x01, 0xf0, initial_u << 4);
	stv0297_writereg_mask(state, 0x01, 0x0f, blind_u);

	/* data comes from internal A/D */
	stv0297_writereg_mask(state, 0x87, 0x80, 0x00);

	/* clear phase registers */
	stv0297_writereg(state, 0x63, 0x00);
	stv0297_writereg(state, 0x64, 0x00);
	stv0297_writereg(state, 0x65, 0x00);
	stv0297_writereg(state, 0x66, 0x00);
	stv0297_writereg(state, 0x67, 0x00);
	stv0297_writereg(state, 0x68, 0x00);
	stv0297_writereg_mask(state, 0x69, 0x0f, 0x00);

	/* set parameters */
	stv0297_set_qam(state, p->modulation);
	stv0297_set_symbolrate(state, p->symbol_rate / 1000);
	stv0297_set_sweeprate(state, sweeprate, p->symbol_rate / 1000);
	stv0297_set_carrieroffset(state, carrieroffset);
	stv0297_set_inversion(state, inversion);

	/* kick off lock */
	/* Disable corner detection for higher QAMs */
	if (p->modulation == QAM_128 \|\|
	p->modulation == QAM_256)
	stv0297_writereg_mask(state, 0x88, 0x08, 0x00);
	else
	stv0297_writereg_mask(state, 0x88, 0x08, 0x08);

	stv0297_writereg_mask(state, 0x5a, 0x20, 0x00);
	stv0297_writereg_mask(state, 0x6a, 0x01, 0x01);
	stv0297_writereg_mask(state, 0x43, 0x40, 0x40);
	stv0297_writereg_mask(state, 0x5b, 0x30, 0x00);
	stv0297_writereg_mask(state, 0x03, 0x0c, 0x0c);
	stv0297_writereg_mask(state, 0x03, 0x03, 0x03);
	stv0297_writereg_mask(state, 0x43, 0x10, 0x10);

	/* wait for WGAGC lock */
	timeout = jiffies + msecs_to_jiffies(2000);
	while (time_before(jiffies, timeout)) {
	msleep(10);
	if (stv0297_readreg(state, 0x43) & 0x08)
	break;
	}
	if (time_after(jiffies, timeout)) {
	goto timeout;
	}
	msleep(20);

	/* wait for equaliser partial convergence */
	timeout = jiffies + msecs_to_jiffies(500);
	while (time_before(jiffies, timeout)) {
	msleep(10);

	if (stv0297_readreg(state, 0x82) & 0x04) {
	break;
	}
	}
	if (time_after(jiffies, timeout)) {
	goto timeout;
	}

	/* wait for equaliser full convergence */
	timeout = jiffies + msecs_to_jiffies(delay);
	while (time_before(jiffies, timeout)) {
	msleep(10);

	if (stv0297_readreg(state, 0x82) & 0x08) {
	break;
	}
	}
	if (time_after(jiffies, timeout)) {
	goto timeout;
	}

	/* disable sweep */
	stv0297_writereg_mask(state, 0x6a, 1, 0);
	stv0297_writereg_mask(state, 0x88, 8, 0);

	/* wait for main lock */
	timeout = jiffies + msecs_to_jiffies(20);
	while (time_before(jiffies, timeout)) {
	msleep(10);

	if (stv0297_readreg(state, 0xDF) & 0x80) {
	break;
	}
	}
	if (time_after(jiffies, timeout)) {
	goto timeout;
	}
	msleep(100);

	/* is it still locked after that delay? */
	if (!(stv0297_readreg(state, 0xDF) & 0x80)) {
	goto timeout;
	}

	/* success!! */
	stv0297_writereg_mask(state, 0x5a, 0x40, 0x00);
	state->base_freq = p->frequency;
	return 0;

	timeout:
	stv0297_writereg_mask(state, 0x6a, 0x01, 0x00);
	return 0;
	}

	static int stv0297_get_frontend(struct dvb_frontend *fe,
	struct dtv_frontend_properties *p)
	{
	struct stv0297_state *state = fe->demodulator_priv;
	int reg_00, reg_83;

	reg_00 = stv0297_readreg(state, 0x00);
	reg_83 = stv0297_readreg(state, 0x83);

	p->frequency = state->base_freq;
	p->inversion = (reg_83 & 0x08) ? INVERSION_ON : INVERSION_OFF;
	if (state->config->invert)
	p->inversion = (p->inversion == INVERSION_ON) ? INVERSION_OFF : INVERSION_ON;
	p->symbol_rate = stv0297_get_symbolrate(state) * 1000;
	p->fec_inner = FEC_NONE;

	switch ((reg_00 >> 4) & 0x7) {
	case 0:
	p->modulation = QAM_16;
	break;
	case 1:
	p->modulation = QAM_32;
	break;
	case 2:
	p->modulation = QAM_128;
	break;
	case 3:
	p->modulation = QAM_256;
	break;
	case 4:
	p->modulation = QAM_64;
	break;
	}

	return 0;
	}

	static void stv0297_release(struct dvb_frontend *fe)
	{
	struct stv0297_state *state = fe->demodulator_priv;
	kfree(state);
	}

	static const struct dvb_frontend_ops stv0297_ops;

	struct dvb_frontend stv0297_attach(const struct stv0297_config config,
	struct i2c_adapter *i2c)
	{
	struct stv0297_state *state = NULL;

	/* allocate memory for the internal state */
	state = kzalloc(sizeof(struct stv0297_state), GFP_KERNEL);
	if (state == NULL)
	goto error;

	/* setup the state */
	state->config = config;
	state->i2c = i2c;
	state->last_ber = 0;
	state->base_freq = 0;

	/* check if the demod is there */
	if ((stv0297_readreg(state, 0x80) & 0x70) != 0x20)
	goto error;

	/* create dvb_frontend */
	memcpy(&state->frontend.ops, &stv0297_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 stv0297_ops = {
	.delsys = { SYS_DVBC_ANNEX_A },
	.info = {
	.name = "ST STV0297 DVB-C",
	.frequency_min_hz = 47 * MHz,
	.frequency_max_hz = 862 * MHz,
	.frequency_stepsize_hz = 62500,
	.symbol_rate_min = 870000,
	.symbol_rate_max = 11700000,
	.caps = 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 = stv0297_release,

	.init = stv0297_init,
	.sleep = stv0297_sleep,
	.i2c_gate_ctrl = stv0297_i2c_gate_ctrl,

	.set_frontend = stv0297_set_frontend,
	.get_frontend = stv0297_get_frontend,

	.read_status = stv0297_read_status,
	.read_ber = stv0297_read_ber,
	.read_signal_strength = stv0297_read_signal_strength,
	.read_snr = stv0297_read_snr,
	.read_ucblocks = stv0297_read_ucblocks,
	};

	MODULE_DESCRIPTION("ST STV0297 DVB-C Demodulator driver");
	MODULE_AUTHOR("Dennis Noermann and Andrew de Quincey");
	MODULE_LICENSE("GPL");

	EXPORT_SYMBOL(stv0297_attach);