/*
   *  Driver for Microtune MT2266 "Direct conversion low power broadband tuner"
   *
   *  Copyright (c) 2007 Olivier DANET <odanet@caramail.com>
   *
   *  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.
   */
  
  #include <linux/module.h>
  #include <linux/delay.h>
  #include <linux/dvb/frontend.h>
  #include <linux/i2c.h>
  #include <linux/slab.h>
  
  #include "dvb_frontend.h"
  #include "mt2266.h"
  
  #define I2C_ADDRESS 0x60
  
  #define REG_PART_REV   0
  #define REG_TUNE       1
  #define REG_BAND       6
  #define REG_BANDWIDTH  8
  #define REG_LOCK       0x12
  
  #define PART_REV 0x85
  
  struct mt2266_priv {
  	struct mt2266_config *cfg;
  	struct i2c_adapter   *i2c;
  
  	u32 frequency;
  	u32 bandwidth;
  	u8 band;
  };
  
  #define MT2266_VHF 1
  #define MT2266_UHF 0
  
  /* Here, frequencies are expressed in kiloHertz to avoid 32 bits overflows */
  
  static int debug;
  module_param(debug, int, 0644);
  MODULE_PARM_DESC(debug, "Turn on/off debugging (default:off).");
  
  #define dprintk(args...) do { if (debug) {printk(KERN_DEBUG "MT2266: " args); printk("
  "); }} while (0)
  
  // Reads a single register
  static int mt2266_readreg(struct mt2266_priv *priv, u8 reg, u8 *val)
  {
  	struct i2c_msg msg[2] = {
  		{ .addr = priv->cfg->i2c_address, .flags = 0,        .buf = &reg, .len = 1 },
  		{ .addr = priv->cfg->i2c_address, .flags = I2C_M_RD, .buf = val,  .len = 1 },
  	};
  	if (i2c_transfer(priv->i2c, msg, 2) != 2) {
  		printk(KERN_WARNING "MT2266 I2C read failed
  ");
  		return -EREMOTEIO;
  	}
  	return 0;
  }
  
  // Writes a single register
  static int mt2266_writereg(struct mt2266_priv *priv, u8 reg, u8 val)
  {
  	u8 buf[2] = { reg, val };
  	struct i2c_msg msg = {
  		.addr = priv->cfg->i2c_address, .flags = 0, .buf = buf, .len = 2
  	};
  	if (i2c_transfer(priv->i2c, &msg, 1) != 1) {
  		printk(KERN_WARNING "MT2266 I2C write failed
  ");
  		return -EREMOTEIO;
  	}
  	return 0;
  }
  
  // Writes a set of consecutive registers
  static int mt2266_writeregs(struct mt2266_priv *priv,u8 *buf, u8 len)
  {
  	struct i2c_msg msg = {
  		.addr = priv->cfg->i2c_address, .flags = 0, .buf = buf, .len = len
  	};
  	if (i2c_transfer(priv->i2c, &msg, 1) != 1) {
  		printk(KERN_WARNING "MT2266 I2C write failed (len=%i)
  ",(int)len);
  		return -EREMOTEIO;
  	}
  	return 0;
  }
  
  // Initialisation sequences
  static u8 mt2266_init1[] = { REG_TUNE, 0x00, 0x00, 0x28,
  				 0x00, 0x52, 0x99, 0x3f };
  
  static u8 mt2266_init2[] = {
      0x17, 0x6d, 0x71, 0x61, 0xc0, 0xbf, 0xff, 0xdc, 0x00, 0x0a, 0xd4,
      0x03, 0x64, 0x64, 0x64, 0x64, 0x22, 0xaa, 0xf2, 0x1e, 0x80, 0x14,
      0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x7f, 0x5e, 0x3f, 0xff, 0xff,
      0xff, 0x00, 0x77, 0x0f, 0x2d
  };
  
  static u8 mt2266_init_8mhz[] = { REG_BANDWIDTH, 0x22, 0x22, 0x22, 0x22,
  						0x22, 0x22, 0x22, 0x22 };
  
  static u8 mt2266_init_7mhz[] = { REG_BANDWIDTH, 0x32, 0x32, 0x32, 0x32,
  						0x32, 0x32, 0x32, 0x32 };
  
  static u8 mt2266_init_6mhz[] = { REG_BANDWIDTH, 0xa7, 0xa7, 0xa7, 0xa7,
  						0xa7, 0xa7, 0xa7, 0xa7 };
  
  static u8 mt2266_uhf[] = { 0x1d, 0xdc, 0x00, 0x0a, 0xd4, 0x03, 0x64, 0x64,
  			   0x64, 0x64, 0x22, 0xaa, 0xf2, 0x1e, 0x80, 0x14 };
  
  static u8 mt2266_vhf[] = { 0x1d, 0xfe, 0x00, 0x00, 0xb4, 0x03, 0xa5, 0xa5,
  			   0xa5, 0xa5, 0x82, 0xaa, 0xf1, 0x17, 0x80, 0x1f };
  
  #define FREF 30000       // Quartz oscillator 30 MHz
  
  static int mt2266_set_params(struct dvb_frontend *fe)
  {
  	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
  	struct mt2266_priv *priv;
  	int ret=0;
  	u32 freq;
  	u32 tune;
  	u8  lnaband;
  	u8  b[10];
  	int i;
  	u8 band;
  
  	priv = fe->tuner_priv;
  
  	freq = priv->frequency / 1000; /* Hz -> kHz */
  	if (freq < 470000 && freq > 230000)
  		return -EINVAL; /* Gap between VHF and UHF bands */
  
  	priv->frequency = c->frequency;
  	tune = 2 * freq * (8192/16) / (FREF/16);
  	band = (freq < 300000) ? MT2266_VHF : MT2266_UHF;
  	if (band == MT2266_VHF)
  		tune *= 2;
  
  	switch (c->bandwidth_hz) {
  	case 6000000:
  		mt2266_writeregs(priv, mt2266_init_6mhz,
  				 sizeof(mt2266_init_6mhz));
  		break;
  	case 8000000:
  		mt2266_writeregs(priv, mt2266_init_8mhz,
  				 sizeof(mt2266_init_8mhz));
  		break;
  	case 7000000:
  	default:
  		mt2266_writeregs(priv, mt2266_init_7mhz,
  				 sizeof(mt2266_init_7mhz));
  		break;
  	}
  	priv->bandwidth = c->bandwidth_hz;
  
  	if (band == MT2266_VHF && priv->band == MT2266_UHF) {
  		dprintk("Switch from UHF to VHF");
  		mt2266_writereg(priv, 0x05, 0x04);
  		mt2266_writereg(priv, 0x19, 0x61);
  		mt2266_writeregs(priv, mt2266_vhf, sizeof(mt2266_vhf));
  	} else if (band == MT2266_UHF && priv->band == MT2266_VHF) {
  		dprintk("Switch from VHF to UHF");
  		mt2266_writereg(priv, 0x05, 0x52);
  		mt2266_writereg(priv, 0x19, 0x61);
  		mt2266_writeregs(priv, mt2266_uhf, sizeof(mt2266_uhf));
  	}
  	msleep(10);
  
  	if (freq <= 495000)
  		lnaband = 0xEE;
  	else if (freq <= 525000)
  		lnaband = 0xDD;
  	else if (freq <= 550000)
  		lnaband = 0xCC;
  	else if (freq <= 580000)
  		lnaband = 0xBB;
  	else if (freq <= 605000)
  		lnaband = 0xAA;
  	else if (freq <= 630000)
  		lnaband = 0x99;
  	else if (freq <= 655000)
  		lnaband = 0x88;
  	else if (freq <= 685000)
  		lnaband = 0x77;
  	else if (freq <= 710000)
  		lnaband = 0x66;
  	else if (freq <= 735000)
  		lnaband = 0x55;
  	else if (freq <= 765000)
  		lnaband = 0x44;
  	else if (freq <= 802000)
  		lnaband = 0x33;
  	else if (freq <= 840000)
  		lnaband = 0x22;
  	else
  		lnaband = 0x11;
  
  	b[0] = REG_TUNE;
  	b[1] = (tune >> 8) & 0x1F;
  	b[2] = tune & 0xFF;
  	b[3] = tune >> 13;
  	mt2266_writeregs(priv,b,4);
  
  	dprintk("set_parms: tune=%d band=%d %s",
  		(int) tune, (int) lnaband,
  		(band == MT2266_UHF) ? "UHF" : "VHF");
  	dprintk("set_parms: [1..3]: %2x %2x %2x",
  		(int) b[1], (int) b[2], (int)b[3]);
  
  	if (band == MT2266_UHF) {
  		b[0] = 0x05;
  		b[1] = (priv->band == MT2266_VHF) ? 0x52 : 0x62;
  		b[2] = lnaband;
  		mt2266_writeregs(priv, b, 3);
  	}
  
  	/* Wait for pll lock or timeout */
  	i = 0;
  	do {
  		mt2266_readreg(priv,REG_LOCK,b);
  		if (b[0] & 0x40)
  			break;
  		msleep(10);
  		i++;
  	} while (i<10);
  	dprintk("Lock when i=%i",(int)i);
  
  	if (band == MT2266_UHF && priv->band == MT2266_VHF)
  		mt2266_writereg(priv, 0x05, 0x62);
  
  	priv->band = band;
  
  	return ret;
  }
  
  static void mt2266_calibrate(struct mt2266_priv *priv)
  {
  	mt2266_writereg(priv, 0x11, 0x03);
  	mt2266_writereg(priv, 0x11, 0x01);
  	mt2266_writeregs(priv, mt2266_init1, sizeof(mt2266_init1));
  	mt2266_writeregs(priv, mt2266_init2, sizeof(mt2266_init2));
  	mt2266_writereg(priv, 0x33, 0x5e);
  	mt2266_writereg(priv, 0x10, 0x10);
  	mt2266_writereg(priv, 0x10, 0x00);
  	mt2266_writeregs(priv, mt2266_init_8mhz, sizeof(mt2266_init_8mhz));
  	msleep(25);
  	mt2266_writereg(priv, 0x17, 0x6d);
  	mt2266_writereg(priv, 0x1c, 0x00);
  	msleep(75);
  	mt2266_writereg(priv, 0x17, 0x6d);
  	mt2266_writereg(priv, 0x1c, 0xff);
  }
  
  static int mt2266_get_frequency(struct dvb_frontend *fe, u32 *frequency)
  {
  	struct mt2266_priv *priv = fe->tuner_priv;
  	*frequency = priv->frequency;
  	return 0;
  }
  
  static int mt2266_get_bandwidth(struct dvb_frontend *fe, u32 *bandwidth)
  {
  	struct mt2266_priv *priv = fe->tuner_priv;
  	*bandwidth = priv->bandwidth;
  	return 0;
  }
  
  static int mt2266_init(struct dvb_frontend *fe)
  {
  	int ret;
  	struct mt2266_priv *priv = fe->tuner_priv;
  	ret = mt2266_writereg(priv, 0x17, 0x6d);
  	if (ret < 0)
  		return ret;
  	ret = mt2266_writereg(priv, 0x1c, 0xff);
  	if (ret < 0)
  		return ret;
  	return 0;
  }
  
  static int mt2266_sleep(struct dvb_frontend *fe)
  {
  	struct mt2266_priv *priv = fe->tuner_priv;
  	mt2266_writereg(priv, 0x17, 0x6d);
  	mt2266_writereg(priv, 0x1c, 0x00);
  	return 0;
  }
  
  static int mt2266_release(struct dvb_frontend *fe)
  {
  	kfree(fe->tuner_priv);
  	fe->tuner_priv = NULL;
  	return 0;
  }
  
  static const struct dvb_tuner_ops mt2266_tuner_ops = {
  	.info = {
  		.name           = "Microtune MT2266",
  		.frequency_min  = 174000000,
  		.frequency_max  = 862000000,
  		.frequency_step =     50000,
  	},
  	.release       = mt2266_release,
  	.init          = mt2266_init,
  	.sleep         = mt2266_sleep,
  	.set_params    = mt2266_set_params,
  	.get_frequency = mt2266_get_frequency,
  	.get_bandwidth = mt2266_get_bandwidth
  };
  
  struct dvb_frontend * mt2266_attach(struct dvb_frontend *fe, struct i2c_adapter *i2c, struct mt2266_config *cfg)
  {
  	struct mt2266_priv *priv = NULL;
  	u8 id = 0;
  
  	priv = kzalloc(sizeof(struct mt2266_priv), GFP_KERNEL);
  	if (priv == NULL)
  		return NULL;
  
  	priv->cfg      = cfg;
  	priv->i2c      = i2c;
  	priv->band     = MT2266_UHF;
  
  	if (mt2266_readreg(priv, 0, &id)) {
  		kfree(priv);
  		return NULL;
  	}
  	if (id != PART_REV) {
  		kfree(priv);
  		return NULL;
  	}
  	printk(KERN_INFO "MT2266: successfully identified
  ");
  	memcpy(&fe->ops.tuner_ops, &mt2266_tuner_ops, sizeof(struct dvb_tuner_ops));
  
  	fe->tuner_priv = priv;
  	mt2266_calibrate(priv);
  	return fe;
  }
  EXPORT_SYMBOL(mt2266_attach);
  
  MODULE_AUTHOR("Olivier DANET");
  MODULE_DESCRIPTION("Microtune MT2266 silicon tuner driver");
  MODULE_LICENSE("GPL");