/**
   * Driver for Sharp IX2505V (marked B0017) DVB-S silicon tuner
   *
   * Copyright (C) 2010 Malcolm Priestley
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License Version 2, as
   * published by the Free Software Foundation.
   *
   * 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/module.h>
  #include <linux/dvb/frontend.h>
  #include <linux/slab.h>
  #include <linux/types.h>
  
  #include "ix2505v.h"
  
  static int ix2505v_debug;
  #define dprintk(level, args...) do { \
  	if (ix2505v_debug & level) \
  		printk(KERN_DEBUG "ix2505v: " args); \
  } while (0)
  
  #define deb_info(args...)  dprintk(0x01, args)
  #define deb_i2c(args...)  dprintk(0x02, args)
  
  struct ix2505v_state {
  	struct i2c_adapter *i2c;
  	const struct ix2505v_config *config;
  	u32 frequency;
  };
  
  /**
   *  Data read format of the Sharp IX2505V B0017
   *
   *  byte1:   1   |   1   |   0   |   0   |   0   |  MA1  |  MA0  |  1
   *  byte2:  POR  |   FL  |  RD2  |  RD1  |  RD0  |   X   |   X   |  X
   *
   *  byte1 = address
   *  byte2;
   *	POR = Power on Reset (VCC H=<2.2v L=>2.2v)
   *	FL  = Phase Lock (H=lock L=unlock)
   *	RD0-2 = Reserved internal operations
   *
   * Only POR can be used to check the tuner is present
   *
   * Caution: after byte2 the I2C reverts to write mode continuing to read
   *          may corrupt tuning data.
   *
   */
  
  static int ix2505v_read_status_reg(struct ix2505v_state *state)
  {
  	u8 addr = state->config->tuner_address;
  	u8 b2[] = {0};
  	int ret;
  
  	struct i2c_msg msg[1] = {
  		{ .addr = addr, .flags = I2C_M_RD, .buf = b2, .len = 1 }
  	};
  
  	ret = i2c_transfer(state->i2c, msg, 1);
  	deb_i2c("Read %s ", __func__);
  
  	return (ret == 1) ? (int) b2[0] : -1;
  }
  
  static int ix2505v_write(struct ix2505v_state *state, u8 buf[], u8 count)
  {
  	struct i2c_msg msg[1] = {
  		{ .addr = state->config->tuner_address, .flags = 0,
  		  .buf = buf, .len = count },
  	};
  
  	int ret;
  
  	ret = i2c_transfer(state->i2c, msg, 1);
  
  	if (ret != 1) {
  		deb_i2c("%s: i2c error, ret=%d
  ", __func__, ret);
  		return -EIO;
  	}
  
  	return 0;
  }
  
  static int ix2505v_release(struct dvb_frontend *fe)
  {
  	struct ix2505v_state *state = fe->tuner_priv;
  
  	fe->tuner_priv = NULL;
  	kfree(state);
  
  	return 0;
  }
  
  /**
   *  Data write format of the Sharp IX2505V B0017
   *
   *  byte1:   1   |   1   |   0   |   0   |   0   | 0(MA1)| 0(MA0)|  0
   *  byte2:   0   |  BG1  |  BG2  |   N8  |   N7  |   N6  |  N5   |  N4
   *  byte3:   N3  |   N2  |   N1  |   A5  |   A4  |   A3  |   A2  |  A1
   *  byte4:   1   | 1(C1) | 1(C0) |  PD5  |  PD4  |   TM  | 0(RTS)| 1(REF)
   *  byte5:   BA2 |   BA1 |  BA0  |  PSC  |  PD3  |PD2/TS2|DIV/TS1|PD0/TS0
   *
   *  byte1 = address
   *
   *  Write order
   *  1) byte1 -> byte2 -> byte3 -> byte4 -> byte5
   *  2) byte1 -> byte4 -> byte5 -> byte2 -> byte3
   *  3) byte1 -> byte2 -> byte3 -> byte4
   *  4) byte1 -> byte4 -> byte5 -> byte2
   *  5) byte1 -> byte2 -> byte3
   *  6) byte1 -> byte4 -> byte5
   *  7) byte1 -> byte2
   *  8) byte1 -> byte4
   *
   *  Recommended Setup
   *  1 -> 8 -> 6
   */
  
  static int ix2505v_set_params(struct dvb_frontend *fe)
  {
  	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
  	struct ix2505v_state *state = fe->tuner_priv;
  	u32 frequency = c->frequency;
  	u32 b_w  = (c->symbol_rate * 27) / 32000;
  	u32 div_factor, N , A, x;
  	int ret = 0, len;
  	u8 gain, cc, ref, psc, local_osc, lpf;
  	u8 data[4] = {0};
  
  	if ((frequency < fe->ops.info.frequency_min)
  	||  (frequency > fe->ops.info.frequency_max))
  		return -EINVAL;
  
  	if (state->config->tuner_gain)
  		gain = (state->config->tuner_gain < 4)
  			? state->config->tuner_gain : 0;
  	else
  		gain = 0x0;
  
  	if (state->config->tuner_chargepump)
  		cc = state->config->tuner_chargepump;
  	else
  		cc = 0x3;
  
  	ref = 8; /* REF =1 */
  	psc = 32; /* PSC = 0 */
  
  	div_factor = (frequency * ref) / 40; /* local osc = 4Mhz */
  	x = div_factor / psc;
  	N = x/100;
  	A = ((x - (N * 100)) * psc) / 100;
  
  	data[0] = ((gain & 0x3) << 5) | (N >> 3);
  	data[1] = (N << 5) | (A & 0x1f);
  	data[2] = 0x81 | ((cc & 0x3) << 5) ; /*PD5,PD4 & TM = 0|C1,C0|REF=1*/
  
  	deb_info("Frq=%d x=%d N=%d A=%d
  ", frequency, x, N, A);
  
  	if (frequency <= 1065000)
  		local_osc = (6 << 5) | 2;
  	else if (frequency <= 1170000)
  		local_osc = (7 << 5) | 2;
  	else if (frequency <= 1300000)
  		local_osc = (1 << 5);
  	else if (frequency <= 1445000)
  		local_osc = (2 << 5);
  	else if (frequency <= 1607000)
  		local_osc = (3 << 5);
  	else if (frequency <= 1778000)
  		local_osc = (4 << 5);
  	else if (frequency <= 1942000)
  		local_osc = (5 << 5);
  	else		/*frequency up to 2150000*/
  		local_osc = (6 << 5);
  
  	data[3] = local_osc; /* all other bits set 0 */
  
  	if (b_w <= 10000)
  		lpf = 0xc;
  	else if (b_w <= 12000)
  		lpf = 0x2;
  	else if (b_w <= 14000)
  		lpf = 0xa;
  	else if (b_w <= 16000)
  		lpf = 0x6;
  	else if (b_w <= 18000)
  		lpf = 0xe;
  	else if (b_w <= 20000)
  		lpf = 0x1;
  	else if (b_w <= 22000)
  		lpf = 0x9;
  	else if (b_w <= 24000)
  		lpf = 0x5;
  	else if (b_w <= 26000)
  		lpf = 0xd;
  	else if (b_w <= 28000)
  		lpf = 0x3;
  		else
  		lpf = 0xb;
  
  	deb_info("Osc=%x b_w=%x lpf=%x
  ", local_osc, b_w, lpf);
  	deb_info("Data 0=[%4phN]
  ", data);
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 1);
  
  	len = sizeof(data);
  	ret |= ix2505v_write(state, data, len);
  
  	data[2] |= 0x4; /* set TM = 1 other bits same */
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 1);
  
  	len = 1;
  	ret |= ix2505v_write(state, &data[2], len); /* write byte 4 only */
  
  	msleep(10);
  
  	data[2] |= ((lpf >> 2) & 0x3) << 3; /* lpf */
  	data[3] |= (lpf & 0x3) << 2;
  
  	deb_info("Data 2=[%x%x]
  ", data[2], data[3]);
  
  	if (fe->ops.i2c_gate_ctrl)
  		fe->ops.i2c_gate_ctrl(fe, 1);
  
  	len = 2;
  	ret |= ix2505v_write(state, &data[2], len); /* write byte 4 & 5 */
  
  	if (state->config->min_delay_ms)
  		msleep(state->config->min_delay_ms);
  
  	state->frequency = frequency;
  
  	return ret;
  }
  
  static int ix2505v_get_frequency(struct dvb_frontend *fe, u32 *frequency)
  {
  	struct ix2505v_state *state = fe->tuner_priv;
  
  	*frequency = state->frequency;
  
  	return 0;
  }
  
  static struct dvb_tuner_ops ix2505v_tuner_ops = {
  	.info = {
  		.name = "Sharp IX2505V (B0017)",
  		.frequency_min = 950000,
  		.frequency_max = 2175000
  	},
  	.release = ix2505v_release,
  	.set_params = ix2505v_set_params,
  	.get_frequency = ix2505v_get_frequency,
  };
  
  struct dvb_frontend *ix2505v_attach(struct dvb_frontend *fe,
  				    const struct ix2505v_config *config,
  				    struct i2c_adapter *i2c)
  {
  	struct ix2505v_state *state = NULL;
  	int ret;
  
  	if (NULL == config) {
  		deb_i2c("%s: no config ", __func__);
  		goto error;
  	}
  
  	state = kzalloc(sizeof(struct ix2505v_state), GFP_KERNEL);
  	if (NULL == state)
  		return NULL;
  
  	state->config = config;
  	state->i2c = i2c;
  
  	if (state->config->tuner_write_only) {
  		if (fe->ops.i2c_gate_ctrl)
  			fe->ops.i2c_gate_ctrl(fe, 1);
  
  		ret = ix2505v_read_status_reg(state);
  
  		if (ret & 0x80) {
  			deb_i2c("%s: No IX2505V found
  ", __func__);
  			goto error;
  		}
  
  		if (fe->ops.i2c_gate_ctrl)
  			fe->ops.i2c_gate_ctrl(fe, 0);
  	}
  
  	fe->tuner_priv = state;
  
  	memcpy(&fe->ops.tuner_ops, &ix2505v_tuner_ops,
  		sizeof(struct dvb_tuner_ops));
  	deb_i2c("%s: initialization (%s addr=0x%02x) ok
  ",
  		__func__, fe->ops.tuner_ops.info.name, config->tuner_address);
  
  	return fe;
  
  error:
  	kfree(state);
  	return NULL;
  }
  EXPORT_SYMBOL(ix2505v_attach);
  
  module_param_named(debug, ix2505v_debug, int, 0644);
  MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
  MODULE_DESCRIPTION("DVB IX2505V tuner driver");
  MODULE_AUTHOR("Malcolm Priestley");
  MODULE_LICENSE("GPL");