/**
   * Driver for Infineon tua6100 pll.
   *
   * (c) 2006 Andrew de Quincey
   *
   * Based on code found in budget-av.c, which has the following:
   * Compiled from various sources by Michael Hunold <michael@mihu.de>
   *
   * CI interface support (c) 2004 Olivier Gournet <ogournet@anevia.com> &
   *                               Andrew de Quincey <adq_dvb@lidskialf.net>
   *
   * Copyright (C) 2002 Ralph Metzler <rjkm@metzlerbros.de>
   *
   * Copyright (C) 1999-2002 Ralph  Metzler
   *                       & Marcus Metzler for convergence integrated media GmbH
   * 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 <asm/types.h>
  
  #include "tua6100.h"
  
  struct tua6100_priv {
  	/* i2c details */
  	int i2c_address;
  	struct i2c_adapter *i2c;
  	u32 frequency;
  };
  
  static int tua6100_release(struct dvb_frontend *fe)
  {
  	kfree(fe->tuner_priv);
  	fe->tuner_priv = NULL;
  	return 0;
  }
  
  static int tua6100_sleep(struct dvb_frontend *fe)
  {
  	struct tua6100_priv *priv = fe->tuner_priv;
  	int ret;
  	u8 reg0[] = { 0x00, 0x00 };
  	struct i2c_msg msg = { .addr = priv->i2c_address, .flags = 0, .buf = reg0, .len = 2 };
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 1);
  	if ((ret = i2c_transfer (priv->i2c, &msg, 1)) != 1) {
  		printk("%s: i2c error
  ", __func__);
  	}
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 0);
  
  	return (ret == 1) ? 0 : ret;
  }
  
  static int tua6100_set_params(struct dvb_frontend *fe)
  {
  	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
  	struct tua6100_priv *priv = fe->tuner_priv;
  	u32 div;
  	u32 prediv;
  	u8 reg0[] = { 0x00, 0x00 };
  	u8 reg1[] = { 0x01, 0x00, 0x00, 0x00 };
  	u8 reg2[] = { 0x02, 0x00, 0x00 };
  	struct i2c_msg msg0 = { .addr = priv->i2c_address, .flags = 0, .buf = reg0, .len = 2 };
  	struct i2c_msg msg1 = { .addr = priv->i2c_address, .flags = 0, .buf = reg1, .len = 4 };
  	struct i2c_msg msg2 = { .addr = priv->i2c_address, .flags = 0, .buf = reg2, .len = 3 };
  
  #define _R 4
  #define _P 32
  #define _ri 4000000
  
  	// setup register 0
  	if (c->frequency < 2000000)
  		reg0[1] = 0x03;
  	else
  		reg0[1] = 0x07;
  
  	// setup register 1
  	if (c->frequency < 1630000)
  		reg1[1] = 0x2c;
  	else
  		reg1[1] = 0x0c;
  
  	if (_P == 64)
  		reg1[1] |= 0x40;
  	if (c->frequency >= 1525000)
  		reg1[1] |= 0x80;
  
  	// register 2
  	reg2[1] = (_R >> 8) & 0x03;
  	reg2[2] = _R;
  	if (c->frequency < 1455000)
  		reg2[1] |= 0x1c;
  	else if (c->frequency < 1630000)
  		reg2[1] |= 0x0c;
  	else
  		reg2[1] |= 0x1c;
  
  	/*
  	 * The N divisor ratio (note: c->frequency is in kHz, but we
  	 * need it in Hz)
  	 */
  	prediv = (c->frequency * _R) / (_ri / 1000);
  	div = prediv / _P;
  	reg1[1] |= (div >> 9) & 0x03;
  	reg1[2] = div >> 1;
  	reg1[3] = (div << 7);
  	priv->frequency = ((div * _P) * (_ri / 1000)) / _R;
  
  	// Finally, calculate and store the value for A
  	reg1[3] |= (prediv - (div*_P)) & 0x7f;
  
  #undef _R
  #undef _P
  #undef _ri
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 1);
  	if (i2c_transfer(priv->i2c, &msg0, 1) != 1)
  		return -EIO;
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 1);
  	if (i2c_transfer(priv->i2c, &msg2, 1) != 1)
  		return -EIO;
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 1);
  	if (i2c_transfer(priv->i2c, &msg1, 1) != 1)
  		return -EIO;
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 0);
  
  	return 0;
  }
  
  static int tua6100_get_frequency(struct dvb_frontend *fe, u32 *frequency)
  {
  	struct tua6100_priv *priv = fe->tuner_priv;
  	*frequency = priv->frequency;
  	return 0;
  }
  
  static struct dvb_tuner_ops tua6100_tuner_ops = {
  	.info = {
  		.name = "Infineon TUA6100",
  		.frequency_min = 950000,
  		.frequency_max = 2150000,
  		.frequency_step = 1000,
  	},
  	.release = tua6100_release,
  	.sleep = tua6100_sleep,
  	.set_params = tua6100_set_params,
  	.get_frequency = tua6100_get_frequency,
  };
  
  struct dvb_frontend *tua6100_attach(struct dvb_frontend *fe, int addr, struct i2c_adapter *i2c)
  {
  	struct tua6100_priv *priv = NULL;
  	u8 b1 [] = { 0x80 };
  	u8 b2 [] = { 0x00 };
  	struct i2c_msg msg [] = { { .addr = addr, .flags = 0, .buf = b1, .len = 1 },
  				  { .addr = addr, .flags = I2C_M_RD, .buf = b2, .len = 1 } };
  	int ret;
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 1);
  	ret = i2c_transfer (i2c, msg, 2);
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 0);
  
  	if (ret != 2)
  		return NULL;
  
  	priv = kzalloc(sizeof(struct tua6100_priv), GFP_KERNEL);
  	if (priv == NULL)
  		return NULL;
  
  	priv->i2c_address = addr;
  	priv->i2c = i2c;
  
  	memcpy(&fe->ops.tuner_ops, &tua6100_tuner_ops, sizeof(struct dvb_tuner_ops));
  	fe->tuner_priv = priv;
  	return fe;
  }
  EXPORT_SYMBOL(tua6100_attach);
  
  MODULE_DESCRIPTION("DVB tua6100 driver");
  MODULE_AUTHOR("Andrew de Quincey");
  MODULE_LICENSE("GPL");