/*
  	TDA665x tuner driver
  	Copyright (C) Manu Abraham (abraham.manu@gmail.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.
  
  	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/init.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  
  #include "dvb_frontend.h"
  #include "tda665x.h"
  
  struct tda665x_state {
  	struct dvb_frontend		*fe;
  	struct i2c_adapter		*i2c;
  	const struct tda665x_config	*config;
  
  	u32 frequency;
  	u32 bandwidth;
  };
  
  static int tda665x_read(struct tda665x_state *state, u8 *buf)
  {
  	const struct tda665x_config *config = state->config;
  	int err = 0;
  	struct i2c_msg msg = { .addr = config->addr, .flags = I2C_M_RD, .buf = buf, .len = 2 };
  
  	err = i2c_transfer(state->i2c, &msg, 1);
  	if (err != 1)
  		goto exit;
  
  	return err;
  exit:
  	printk(KERN_ERR "%s: I/O Error err=<%d>
  ", __func__, err);
  	return err;
  }
  
  static int tda665x_write(struct tda665x_state *state, u8 *buf, u8 length)
  {
  	const struct tda665x_config *config = state->config;
  	int err = 0;
  	struct i2c_msg msg = { .addr = config->addr, .flags = 0, .buf = buf, .len = length };
  
  	err = i2c_transfer(state->i2c, &msg, 1);
  	if (err != 1)
  		goto exit;
  
  	return err;
  exit:
  	printk(KERN_ERR "%s: I/O Error err=<%d>
  ", __func__, err);
  	return err;
  }
  
  static int tda665x_get_state(struct dvb_frontend *fe,
  			     enum tuner_param param,
  			     struct tuner_state *tstate)
  {
  	struct tda665x_state *state = fe->tuner_priv;
  	int err = 0;
  
  	switch (param) {
  	case DVBFE_TUNER_FREQUENCY:
  		tstate->frequency = state->frequency;
  		break;
  	case DVBFE_TUNER_BANDWIDTH:
  		break;
  	default:
  		printk(KERN_ERR "%s: Unknown parameter (param=%d)
  ", __func__, param);
  		err = -EINVAL;
  		break;
  	}
  
  	return err;
  }
  
  static int tda665x_get_status(struct dvb_frontend *fe, u32 *status)
  {
  	struct tda665x_state *state = fe->tuner_priv;
  	u8 result = 0;
  	int err = 0;
  
  	*status = 0;
  
  	err = tda665x_read(state, &result);
  	if (err < 0)
  		goto exit;
  
  	if ((result >> 6) & 0x01) {
  		printk(KERN_DEBUG "%s: Tuner Phase Locked
  ", __func__);
  		*status = 1;
  	}
  
  	return err;
  exit:
  	printk(KERN_ERR "%s: I/O Error
  ", __func__);
  	return err;
  }
  
  static int tda665x_set_state(struct dvb_frontend *fe,
  			     enum tuner_param param,
  			     struct tuner_state *tstate)
  {
  	struct tda665x_state *state = fe->tuner_priv;
  	const struct tda665x_config *config = state->config;
  	u32 frequency, status = 0;
  	u8 buf[4];
  	int err = 0;
  
  	if (param & DVBFE_TUNER_FREQUENCY) {
  
  		frequency = tstate->frequency;
  		if ((frequency < config->frequency_max) || (frequency > config->frequency_min)) {
  			printk(KERN_ERR "%s: Frequency beyond limits, frequency=%d
  ", __func__, frequency);
  			return -EINVAL;
  		}
  
  		frequency += config->frequency_offst;
  		frequency *= config->ref_multiplier;
  		frequency += config->ref_divider >> 1;
  		frequency /= config->ref_divider;
  
  		buf[0] = (u8) ((frequency & 0x7f00) >> 8);
  		buf[1] = (u8) (frequency & 0x00ff) >> 0;
  		buf[2] = 0x80 | 0x40 | 0x02;
  		buf[3] = 0x00;
  
  		/* restore frequency */
  		frequency = tstate->frequency;
  
  		if (frequency < 153000000) {
  			/* VHF-L */
  			buf[3] |= 0x01; /* fc, Low Band, 47 - 153 MHz */
  			if (frequency < 68000000)
  				buf[3] |= 0x40; /* 83uA */
  			if (frequency < 1040000000)
  				buf[3] |= 0x60; /* 122uA */
  			if (frequency < 1250000000)
  				buf[3] |= 0x80; /* 163uA */
  			else
  				buf[3] |= 0xa0; /* 254uA */
  		} else if (frequency < 438000000) {
  			/* VHF-H */
  			buf[3] |= 0x02; /* fc, Mid Band, 153 - 438 MHz */
  			if (frequency < 230000000)
  				buf[3] |= 0x40;
  			if (frequency < 300000000)
  				buf[3] |= 0x60;
  			else
  				buf[3] |= 0x80;
  		} else {
  			/* UHF */
  			buf[3] |= 0x04; /* fc, High Band, 438 - 862 MHz */
  			if (frequency < 470000000)
  				buf[3] |= 0x60;
  			if (frequency < 526000000)
  				buf[3] |= 0x80;
  			else
  				buf[3] |= 0xa0;
  		}
  
  		/* Set params */
  		err = tda665x_write(state, buf, 5);
  		if (err < 0)
  			goto exit;
  
  		/* sleep for some time */
  		printk(KERN_DEBUG "%s: Waiting to Phase LOCK
  ", __func__);
  		msleep(20);
  		/* check status */
  		err = tda665x_get_status(fe, &status);
  		if (err < 0)
  			goto exit;
  
  		if (status == 1) {
  			printk(KERN_DEBUG "%s: Tuner Phase locked: status=%d
  ", __func__, status);
  			state->frequency = frequency; /* cache successful state */
  		} else {
  			printk(KERN_ERR "%s: No Phase lock: status=%d
  ", __func__, status);
  		}
  	} else {
  		printk(KERN_ERR "%s: Unknown parameter (param=%d)
  ", __func__, param);
  		return -EINVAL;
  	}
  
  	return 0;
  exit:
  	printk(KERN_ERR "%s: I/O Error
  ", __func__);
  	return err;
  }
  
  static int tda665x_release(struct dvb_frontend *fe)
  {
  	struct tda665x_state *state = fe->tuner_priv;
  
  	fe->tuner_priv = NULL;
  	kfree(state);
  	return 0;
  }
  
  static struct dvb_tuner_ops tda665x_ops = {
  
  	.set_state	= tda665x_set_state,
  	.get_state	= tda665x_get_state,
  	.get_status	= tda665x_get_status,
  	.release	= tda665x_release
  };
  
  struct dvb_frontend *tda665x_attach(struct dvb_frontend *fe,
  				    const struct tda665x_config *config,
  				    struct i2c_adapter *i2c)
  {
  	struct tda665x_state *state = NULL;
  	struct dvb_tuner_info *info;
  
  	state = kzalloc(sizeof(struct tda665x_state), GFP_KERNEL);
  	if (!state)
  		return NULL;
  
  	state->config		= config;
  	state->i2c		= i2c;
  	state->fe		= fe;
  	fe->tuner_priv		= state;
  	fe->ops.tuner_ops	= tda665x_ops;
  	info			 = &fe->ops.tuner_ops.info;
  
  	memcpy(info->name, config->name, sizeof(config->name));
  	info->frequency_min	= config->frequency_min;
  	info->frequency_max	= config->frequency_max;
  	info->frequency_step	= config->frequency_offst;
  
  	printk(KERN_DEBUG "%s: Attaching TDA665x (%s) tuner
  ", __func__, info->name);
  
  	return fe;
  }
  EXPORT_SYMBOL(tda665x_attach);
  
  MODULE_DESCRIPTION("TDA665x driver");
  MODULE_AUTHOR("Manu Abraham");
  MODULE_LICENSE("GPL");