text: /*
   * stv6110.c
   *
   * Driver for ST STV6110 satellite tuner IC.
   *
   * Copyright (C) 2009 NetUP Inc.
   * Copyright (C) 2009 Igor M. Liplianin <liplianin@netup.ru>
   *
   * 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 <linux/slab.h>
  #include <linux/module.h>
  #include <linux/dvb/frontend.h>
  
  #include <linux/types.h>
  
  #include "stv6110.h"
  
  /* Max transfer size done by I2C transfer functions */
  #define MAX_XFER_SIZE  64
  
  static int debug;
  
  struct stv6110_priv {
  	int i2c_address;
  	struct i2c_adapter *i2c;
  
  	u32 mclk;
  	u8 clk_div;
  	u8 gain;
  	u8 regs[8];
  };
  
  #define dprintk(args...) \
  	do { \
  		if (debug) \
  			printk(KERN_DEBUG args); \
  	} while (0)
  
  static s32 abssub(s32 a, s32 b)
  {
  	if (a > b)
  		return a - b;
  	else
  		return b - a;
  };
  
  static int stv6110_release(struct dvb_frontend *fe)
  {
  	kfree(fe->tuner_priv);
  	fe->tuner_priv = NULL;
  	return 0;
  }
  
  static int stv6110_write_regs(struct dvb_frontend *fe, u8 buf[],
  							int start, int len)
  {
  	struct stv6110_priv *priv = fe->tuner_priv;
  	int rc;
  	u8 cmdbuf[MAX_XFER_SIZE];
  	struct i2c_msg msg = {
  		.addr	= priv->i2c_address,
  		.flags	= 0,
  		.buf	= cmdbuf,
  		.len	= len + 1
  	};
  
  	dprintk("%s\n", __func__);
  
  	if (1 + len > sizeof(cmdbuf)) {
  		printk(KERN_WARNING
  		       "%s: i2c wr: len=%d is too big!\n",
  		       KBUILD_MODNAME, len);
  		return -EINVAL;
  	}
  
  	if (start + len > 8)
  		return -EINVAL;
  
  	memcpy(&cmdbuf[1], buf, len);
  	cmdbuf[0] = start;
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 1);
  
  	rc = i2c_transfer(priv->i2c, &msg, 1);
  	if (rc != 1)
  		dprintk("%s: i2c error\n", __func__);
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 0);
  
  	return 0;
  }
  
  static int stv6110_read_regs(struct dvb_frontend *fe, u8 regs[],
  							int start, int len)
  {
  	struct stv6110_priv *priv = fe->tuner_priv;
  	int rc;
  	u8 reg[] = { start };
  	struct i2c_msg msg[] = {
  		{
  			.addr	= priv->i2c_address,
  			.flags	= 0,
  			.buf	= reg,
  			.len	= 1,
  		}, {
  			.addr	= priv->i2c_address,
  			.flags	= I2C_M_RD,
  			.buf	= regs,
  			.len	= len,
  		},
  	};
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 1);
  
  	rc = i2c_transfer(priv->i2c, msg, 2);
  	if (rc != 2)
  		dprintk("%s: i2c error\n", __func__);
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 0);
  
  	memcpy(&priv->regs[start], regs, len);
  
  	return 0;
  }
  
  static int stv6110_read_reg(struct dvb_frontend *fe, int start)
  {
  	u8 buf[] = { 0 };
  	stv6110_read_regs(fe, buf, start, 1);
  
  	return buf[0];
  }
  
  static int stv6110_sleep(struct dvb_frontend *fe)
  {
  	u8 reg[] = { 0 };
  	stv6110_write_regs(fe, reg, 0, 1);
  
  	return 0;
  }
  
  static u32 carrier_width(u32 symbol_rate, enum fe_rolloff rolloff)
  {
  	u32 rlf;
  
  	switch (rolloff) {
  	case ROLLOFF_20:
  		rlf = 20;
  		break;
  	case ROLLOFF_25:
  		rlf = 25;
  		break;
  	default:
  		rlf = 35;
  		break;
  	}
  
  	return symbol_rate  + ((symbol_rate * rlf) / 100);
  }
  
  static int stv6110_set_bandwidth(struct dvb_frontend *fe, u32 bandwidth)
  {
  	struct stv6110_priv *priv = fe->tuner_priv;
  	u8 r8, ret = 0x04;
  	int i;
  
  	if ((bandwidth / 2) > 36000000) /*BW/2 max=31+5=36 mhz for r8=31*/
  		r8 = 31;
  	else if ((bandwidth / 2) < 5000000) /* BW/2 min=5Mhz for F=0 */
  		r8 = 0;
  	else /*if 5 < BW/2 < 36*/
  		r8 = (bandwidth / 2) / 1000000 - 5;
  
  	/* ctrl3, RCCLKOFF = 0 Activate the calibration Clock */
  	/* ctrl3, CF = r8 Set the LPF value */
  	priv->regs[RSTV6110_CTRL3] &= ~((1 << 6) | 0x1f);
  	priv->regs[RSTV6110_CTRL3] |= (r8 & 0x1f);
  	stv6110_write_regs(fe, &priv->regs[RSTV6110_CTRL3], RSTV6110_CTRL3, 1);
  	/* stat1, CALRCSTRT = 1 Start LPF auto calibration*/
  	priv->regs[RSTV6110_STAT1] |= 0x02;
  	stv6110_write_regs(fe, &priv->regs[RSTV6110_STAT1], RSTV6110_STAT1, 1);
  
  	i = 0;
  	/* Wait for CALRCSTRT == 0 */
  	while ((i < 10) && (ret != 0)) {
  		ret = ((stv6110_read_reg(fe, RSTV6110_STAT1)) & 0x02);
  		mdelay(1);	/* wait for LPF auto calibration */
  		i++;
  	}
  
  	/* RCCLKOFF = 1 calibration done, desactivate the calibration Clock */
  	priv->regs[RSTV6110_CTRL3] |= (1 << 6);
  	stv6110_write_regs(fe, &priv->regs[RSTV6110_CTRL3], RSTV6110_CTRL3, 1);
  	return 0;
  }
  
  static int stv6110_init(struct dvb_frontend *fe)
  {
  	struct stv6110_priv *priv = fe->tuner_priv;
  	u8 buf0[] = { 0x07, 0x11, 0xdc, 0x85, 0x17, 0x01, 0xe6, 0x1e };
  
  	memcpy(priv->regs, buf0, 8);
  	/* K = (Reference / 1000000) - 16 */
  	priv->regs[RSTV6110_CTRL1] &= ~(0x1f << 3);
  	priv->regs[RSTV6110_CTRL1] |=
  				((((priv->mclk / 1000000) - 16) & 0x1f) << 3);
  
  	/* divisor value for the output clock */
  	priv->regs[RSTV6110_CTRL2] &= ~0xc0;
  	priv->regs[RSTV6110_CTRL2] |= (priv->clk_div << 6);
  
  	stv6110_write_regs(fe, &priv->regs[RSTV6110_CTRL1], RSTV6110_CTRL1, 8);
  	msleep(1);
  	stv6110_set_bandwidth(fe, 72000000);
  
  	return 0;
  }
  
  static int stv6110_get_frequency(struct dvb_frontend *fe, u32 *frequency)
  {
  	struct stv6110_priv *priv = fe->tuner_priv;
  	u32 nbsteps, divider, psd2, freq;
  	u8 regs[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
  
  	stv6110_read_regs(fe, regs, 0, 8);
  	/*N*/
  	divider = (priv->regs[RSTV6110_TUNING2] & 0x0f) << 8;
  	divider += priv->regs[RSTV6110_TUNING1];
  
  	/*R*/
  	nbsteps  = (priv->regs[RSTV6110_TUNING2] >> 6) & 3;
  	/*p*/
  	psd2  = (priv->regs[RSTV6110_TUNING2] >> 4) & 1;
  
  	freq = divider * (priv->mclk / 1000);
  	freq /= (1 << (nbsteps + psd2));
  	freq /= 4;
  
  	*frequency = freq;
  
  	return 0;
  }
  
  static int stv6110_set_frequency(struct dvb_frontend *fe, u32 frequency)
  {
  	struct stv6110_priv *priv = fe->tuner_priv;
  	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
  	u8 ret = 0x04;
  	u32 divider, ref, p, presc, i, result_freq, vco_freq;
  	s32 p_calc, p_calc_opt = 1000, r_div, r_div_opt = 0, p_val;
  	s32 srate;
  
  	dprintk("%s, freq=%d kHz, mclk=%d Hz\n", __func__,
  						frequency, priv->mclk);
  
  	/* K = (Reference / 1000000) - 16 */
  	priv->regs[RSTV6110_CTRL1] &= ~(0x1f << 3);
  	priv->regs[RSTV6110_CTRL1] |=
  				((((priv->mclk / 1000000) - 16) & 0x1f) << 3);
  
  	/* BB_GAIN = db/2 */
  	if (fe->ops.set_property && fe->ops.get_property) {
  		srate = c->symbol_rate;
  		dprintk("%s: Get Frontend parameters: srate=%d\n",
  							__func__, srate);
  	} else
  		srate = 15000000;
  
  	priv->regs[RSTV6110_CTRL2] &= ~0x0f;
  	priv->regs[RSTV6110_CTRL2] |= (priv->gain & 0x0f);
  
  	if (frequency <= 1023000) {
  		p = 1;
  		presc = 0;
  	} else if (frequency <= 1300000) {
  		p = 1;
  		presc = 1;
  	} else if (frequency <= 2046000) {
  		p = 0;
  		presc = 0;
  	} else {
  		p = 0;
  		presc = 1;
  	}
  	/* DIV4SEL = p*/
  	priv->regs[RSTV6110_TUNING2] &= ~(1 << 4);
  	priv->regs[RSTV6110_TUNING2] |= (p << 4);
  
  	/* PRESC32ON = presc */
  	priv->regs[RSTV6110_TUNING2] &= ~(1 << 5);
  	priv->regs[RSTV6110_TUNING2] |= (presc << 5);
  
  	p_val = (int)(1 << (p + 1)) * 10;/* P = 2 or P = 4 */
  	for (r_div = 0; r_div <= 3; r_div++) {
  		p_calc = (priv->mclk / 100000);
  		p_calc /= (1 << (r_div + 1));
  		if ((abssub(p_calc, p_val)) < (abssub(p_calc_opt, p_val)))
  			r_div_opt = r_div;
  
  		p_calc_opt = (priv->mclk / 100000);
  		p_calc_opt /= (1 << (r_div_opt + 1));
  	}
  
  	ref = priv->mclk / ((1 << (r_div_opt + 1))  * (1 << (p + 1)));
  	divider = (((frequency * 1000) + (ref >> 1)) / ref);
  
  	/* RDIV = r_div_opt */
  	priv->regs[RSTV6110_TUNING2] &= ~(3 << 6);
  	priv->regs[RSTV6110_TUNING2] |= (((r_div_opt) & 3) << 6);
  
  	/* NDIV_MSB = MSB(divider) */
  	priv->regs[RSTV6110_TUNING2] &= ~0x0f;
  	priv->regs[RSTV6110_TUNING2] |= (((divider) >> 8) & 0x0f);
  
  	/* NDIV_LSB, LSB(divider) */
  	priv->regs[RSTV6110_TUNING1] = (divider & 0xff);
  
  	/* CALVCOSTRT = 1 VCO Auto Calibration */
  	priv->regs[RSTV6110_STAT1] |= 0x04;
  	stv6110_write_regs(fe, &priv->regs[RSTV6110_CTRL1],
  						RSTV6110_CTRL1, 8);
  
  	i = 0;
  	/* Wait for CALVCOSTRT == 0 */
  	while ((i < 10) && (ret != 0)) {
  		ret = ((stv6110_read_reg(fe, RSTV6110_STAT1)) & 0x04);
  		msleep(1); /* wait for VCO auto calibration */
  		i++;
  	}
  
  	ret = stv6110_read_reg(fe, RSTV6110_STAT1);
  	stv6110_get_frequency(fe, &result_freq);
  
  	vco_freq = divider * ((priv->mclk / 1000) / ((1 << (r_div_opt + 1))));
  	dprintk("%s, stat1=%x, lo_freq=%d kHz, vco_frec=%d kHz\n", __func__,
  						ret, result_freq, vco_freq);
  
  	return 0;
  }
  
  static int stv6110_set_params(struct dvb_frontend *fe)
  {
  	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
  	u32 bandwidth = carrier_width(c->symbol_rate, c->rolloff);
  
  	stv6110_set_frequency(fe, c->frequency);
  	stv6110_set_bandwidth(fe, bandwidth);
  
  	return 0;
  }
  
  static int stv6110_get_bandwidth(struct dvb_frontend *fe, u32 *bandwidth)
  {
  	struct stv6110_priv *priv = fe->tuner_priv;
  	u8 r8 = 0;
  	u8 regs[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
  	stv6110_read_regs(fe, regs, 0, 8);
  
  	/* CF */
  	r8 = priv->regs[RSTV6110_CTRL3] & 0x1f;
  	*bandwidth = (r8 + 5) * 2000000;/* x2 for ZIF tuner BW/2 = F+5 Mhz */
  
  	return 0;
  }
  
  static const struct dvb_tuner_ops stv6110_tuner_ops = {
  	.info = {
  		.name = "ST STV6110",
  		.frequency_min = 950000,
  		.frequency_max = 2150000,
  		.frequency_step = 1000,
  	},
  	.init = stv6110_init,
  	.release = stv6110_release,
  	.sleep = stv6110_sleep,
  	.set_params = stv6110_set_params,
  	.get_frequency = stv6110_get_frequency,
  	.set_frequency = stv6110_set_frequency,
  	.get_bandwidth = stv6110_get_bandwidth,
  	.set_bandwidth = stv6110_set_bandwidth,
  
  };
  
  struct dvb_frontend *stv6110_attach(struct dvb_frontend *fe,
  					const struct stv6110_config *config,
  					struct i2c_adapter *i2c)
  {
  	struct stv6110_priv *priv = NULL;
  	u8 reg0[] = { 0x00, 0x07, 0x11, 0xdc, 0x85, 0x17, 0x01, 0xe6, 0x1e };
  
  	struct i2c_msg msg[] = {
  		{
  			.addr = config->i2c_address,
  			.flags = 0,
  			.buf = reg0,
  			.len = 9
  		}
  	};
  	int ret;
  
  	/* divisor value for the output clock */
  	reg0[2] &= ~0xc0;
  	reg0[2] |= (config->clk_div << 6);
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 1);
  
  	ret = i2c_transfer(i2c, msg, 1);
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 0);
  
  	if (ret != 1)
  		return NULL;
  
  	priv = kzalloc(sizeof(struct stv6110_priv), GFP_KERNEL);
  	if (priv == NULL)
  		return NULL;
  
  	priv->i2c_address = config->i2c_address;
  	priv->i2c = i2c;
  	priv->mclk = config->mclk;
  	priv->clk_div = config->clk_div;
  	priv->gain = config->gain;
  
  	memcpy(&priv->regs, &reg0[1], 8);
  
  	memcpy(&fe->ops.tuner_ops, &stv6110_tuner_ops,
  				sizeof(struct dvb_tuner_ops));
  	fe->tuner_priv = priv;
  	printk(KERN_INFO "STV6110 attached on addr=%x!\n", priv->i2c_address);
  
  	return fe;
  }
  EXPORT_SYMBOL(stv6110_attach);
  
  module_param(debug, int, 0644);
  MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
  
  MODULE_DESCRIPTION("ST STV6110 driver");
  MODULE_AUTHOR("Igor M. Liplianin");
  MODULE_LICENSE("GPL");
  