/*
      Conexant cx22700 DVB OFDM demodulator driver
  
      Copyright (C) 2001-2002 Convergence Integrated Media GmbH
  	Holger Waechtler <holger@convergence.de>
  
      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/kernel.h>
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/string.h>
  #include <linux/slab.h>
  #include "dvb_frontend.h"
  #include "cx22700.h"
  
  
  struct cx22700_state {
  
  	struct i2c_adapter* i2c;
  
  	const struct cx22700_config* config;
  
  	struct dvb_frontend frontend;
  };
  
  
  static int debug;
  #define dprintk(args...) \
  	do { \
  		if (debug) printk(KERN_DEBUG "cx22700: " args); \
  	} while (0)
  
  static u8 init_tab [] = {
  	0x04, 0x10,
  	0x05, 0x09,
  	0x06, 0x00,
  	0x08, 0x04,
  	0x09, 0x00,
  	0x0a, 0x01,
  	0x15, 0x40,
  	0x16, 0x10,
  	0x17, 0x87,
  	0x18, 0x17,
  	0x1a, 0x10,
  	0x25, 0x04,
  	0x2e, 0x00,
  	0x39, 0x00,
  	0x3a, 0x04,
  	0x45, 0x08,
  	0x46, 0x02,
  	0x47, 0x05,
  };
  
  
  static int cx22700_writereg (struct cx22700_state* state, u8 reg, u8 data)
  {
  	int ret;
  	u8 buf [] = { reg, data };
  	struct i2c_msg msg = { .addr = state->config->demod_address, .flags = 0, .buf = buf, .len = 2 };
  
  	dprintk ("%s
  ", __func__);
  
  	ret = i2c_transfer (state->i2c, &msg, 1);
  
  	if (ret != 1)
  		printk("%s: writereg error (reg == 0x%02x, val == 0x%02x, ret == %i)
  ",
  			__func__, reg, data, ret);
  
  	return (ret != 1) ? -1 : 0;
  }
  
  static int cx22700_readreg (struct cx22700_state* state, u8 reg)
  {
  	int ret;
  	u8 b0 [] = { reg };
  	u8 b1 [] = { 0 };
  	struct i2c_msg msg [] = { { .addr = state->config->demod_address, .flags = 0, .buf = b0, .len = 1 },
  			   { .addr = state->config->demod_address, .flags = I2C_M_RD, .buf = b1, .len = 1 } };
  
  	dprintk ("%s
  ", __func__);
  
  	ret = i2c_transfer (state->i2c, msg, 2);
  
  	if (ret != 2) return -EIO;
  
  	return b1[0];
  }
  
  static int cx22700_set_inversion (struct cx22700_state* state, int inversion)
  {
  	u8 val;
  
  	dprintk ("%s
  ", __func__);
  
  	switch (inversion) {
  	case INVERSION_AUTO:
  		return -EOPNOTSUPP;
  	case INVERSION_ON:
  		val = cx22700_readreg (state, 0x09);
  		return cx22700_writereg (state, 0x09, val | 0x01);
  	case INVERSION_OFF:
  		val = cx22700_readreg (state, 0x09);
  		return cx22700_writereg (state, 0x09, val & 0xfe);
  	default:
  		return -EINVAL;
  	}
  }
  
  static int cx22700_set_tps(struct cx22700_state *state,
  			   struct dtv_frontend_properties *p)
  {
  	static const u8 qam_tab [4] = { 0, 1, 0, 2 };
  	static const u8 fec_tab [6] = { 0, 1, 2, 0, 3, 4 };
  	u8 val;
  
  	dprintk ("%s
  ", __func__);
  
  	if (p->code_rate_HP < FEC_1_2 || p->code_rate_HP > FEC_7_8)
  		return -EINVAL;
  
  	if (p->code_rate_LP < FEC_1_2 || p->code_rate_LP > FEC_7_8)
  		return -EINVAL;
  
  	if (p->code_rate_HP == FEC_4_5 || p->code_rate_LP == FEC_4_5)
  		return -EINVAL;
  
  	if ((int)p->guard_interval < GUARD_INTERVAL_1_32 ||
  	    p->guard_interval > GUARD_INTERVAL_1_4)
  		return -EINVAL;
  
  	if (p->transmission_mode != TRANSMISSION_MODE_2K &&
  	    p->transmission_mode != TRANSMISSION_MODE_8K)
  		return -EINVAL;
  
  	if (p->modulation != QPSK &&
  	    p->modulation != QAM_16 &&
  	    p->modulation != QAM_64)
  		return -EINVAL;
  
  	if ((int)p->hierarchy < HIERARCHY_NONE ||
  	    p->hierarchy > HIERARCHY_4)
  		return -EINVAL;
  
  	if (p->bandwidth_hz > 8000000 || p->bandwidth_hz < 6000000)
  		return -EINVAL;
  
  	if (p->bandwidth_hz == 7000000)
  		cx22700_writereg (state, 0x09, cx22700_readreg (state, 0x09 | 0x10));
  	else
  		cx22700_writereg (state, 0x09, cx22700_readreg (state, 0x09 & ~0x10));
  
  	val = qam_tab[p->modulation - QPSK];
  	val |= p->hierarchy - HIERARCHY_NONE;
  
  	cx22700_writereg (state, 0x04, val);
  
  	val = fec_tab[p->code_rate_HP - FEC_1_2] << 3;
  	val |= fec_tab[p->code_rate_LP - FEC_1_2];
  
  	cx22700_writereg (state, 0x05, val);
  
  	val = (p->guard_interval - GUARD_INTERVAL_1_32) << 2;
  	val |= p->transmission_mode - TRANSMISSION_MODE_2K;
  
  	cx22700_writereg (state, 0x06, val);
  
  	cx22700_writereg (state, 0x08, 0x04 | 0x02);  /* use user tps parameters */
  	cx22700_writereg (state, 0x08, 0x04);         /* restart acquisition */
  
  	return 0;
  }
  
  static int cx22700_get_tps(struct cx22700_state *state,
  			   struct dtv_frontend_properties *p)
  {
  	static const fe_modulation_t qam_tab [3] = { QPSK, QAM_16, QAM_64 };
  	static const fe_code_rate_t fec_tab [5] = { FEC_1_2, FEC_2_3, FEC_3_4,
  						    FEC_5_6, FEC_7_8 };
  	u8 val;
  
  	dprintk ("%s
  ", __func__);
  
  	if (!(cx22700_readreg(state, 0x07) & 0x20))  /*  tps valid? */
  		return -EAGAIN;
  
  	val = cx22700_readreg (state, 0x01);
  
  	if ((val & 0x7) > 4)
  		p->hierarchy = HIERARCHY_AUTO;
  	else
  		p->hierarchy = HIERARCHY_NONE + (val & 0x7);
  
  	if (((val >> 3) & 0x3) > 2)
  		p->modulation = QAM_AUTO;
  	else
  		p->modulation = qam_tab[(val >> 3) & 0x3];
  
  	val = cx22700_readreg (state, 0x02);
  
  	if (((val >> 3) & 0x07) > 4)
  		p->code_rate_HP = FEC_AUTO;
  	else
  		p->code_rate_HP = fec_tab[(val >> 3) & 0x07];
  
  	if ((val & 0x07) > 4)
  		p->code_rate_LP = FEC_AUTO;
  	else
  		p->code_rate_LP = fec_tab[val & 0x07];
  
  	val = cx22700_readreg (state, 0x03);
  
  	p->guard_interval = GUARD_INTERVAL_1_32 + ((val >> 6) & 0x3);
  	p->transmission_mode = TRANSMISSION_MODE_2K + ((val >> 5) & 0x1);
  
  	return 0;
  }
  
  static int cx22700_init (struct dvb_frontend* fe)
  
  {	struct cx22700_state* state = fe->demodulator_priv;
  	int i;
  
  	dprintk("cx22700_init: init chip
  ");
  
  	cx22700_writereg (state, 0x00, 0x02);   /*  soft reset */
  	cx22700_writereg (state, 0x00, 0x00);
  
  	msleep(10);
  
  	for (i=0; i<sizeof(init_tab); i+=2)
  		cx22700_writereg (state, init_tab[i], init_tab[i+1]);
  
  	cx22700_writereg (state, 0x00, 0x01);
  
  	return 0;
  }
  
  static int cx22700_read_status(struct dvb_frontend* fe, fe_status_t* status)
  {
  	struct cx22700_state* state = fe->demodulator_priv;
  
  	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
  		   | (cx22700_readreg (state, 0x0e) << 1);
  	u8 sync = cx22700_readreg (state, 0x07);
  
  	*status = 0;
  
  	if (rs_ber < 0xff00)
  		*status |= FE_HAS_SIGNAL;
  
  	if (sync & 0x20)
  		*status |= FE_HAS_CARRIER;
  
  	if (sync & 0x10)
  		*status |= FE_HAS_VITERBI;
  
  	if (sync & 0x10)
  		*status |= FE_HAS_SYNC;
  
  	if (*status == 0x0f)
  		*status |= FE_HAS_LOCK;
  
  	return 0;
  }
  
  static int cx22700_read_ber(struct dvb_frontend* fe, u32* ber)
  {
  	struct cx22700_state* state = fe->demodulator_priv;
  
  	*ber = cx22700_readreg (state, 0x0c) & 0x7f;
  	cx22700_writereg (state, 0x0c, 0x00);
  
  	return 0;
  }
  
  static int cx22700_read_signal_strength(struct dvb_frontend* fe, u16* signal_strength)
  {
  	struct cx22700_state* state = fe->demodulator_priv;
  
  	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
  		   | (cx22700_readreg (state, 0x0e) << 1);
  	*signal_strength = ~rs_ber;
  
  	return 0;
  }
  
  static int cx22700_read_snr(struct dvb_frontend* fe, u16* snr)
  {
  	struct cx22700_state* state = fe->demodulator_priv;
  
  	u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
  		   | (cx22700_readreg (state, 0x0e) << 1);
  	*snr = ~rs_ber;
  
  	return 0;
  }
  
  static int cx22700_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
  {
  	struct cx22700_state* state = fe->demodulator_priv;
  
  	*ucblocks = cx22700_readreg (state, 0x0f);
  	cx22700_writereg (state, 0x0f, 0x00);
  
  	return 0;
  }
  
  static int cx22700_set_frontend(struct dvb_frontend *fe)
  {
  	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
  	struct cx22700_state* state = fe->demodulator_priv;
  
  	cx22700_writereg (state, 0x00, 0x02); /* XXX CHECKME: soft reset*/
  	cx22700_writereg (state, 0x00, 0x00);
  
  	if (fe->ops.tuner_ops.set_params) {
  		fe->ops.tuner_ops.set_params(fe);
  		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
  	}
  
  	cx22700_set_inversion(state, c->inversion);
  	cx22700_set_tps(state, c);
  	cx22700_writereg (state, 0x37, 0x01);  /* PAL loop filter off */
  	cx22700_writereg (state, 0x00, 0x01);  /* restart acquire */
  
  	return 0;
  }
  
  static int cx22700_get_frontend(struct dvb_frontend *fe)
  {
  	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
  	struct cx22700_state* state = fe->demodulator_priv;
  	u8 reg09 = cx22700_readreg (state, 0x09);
  
  	c->inversion = reg09 & 0x1 ? INVERSION_ON : INVERSION_OFF;
  	return cx22700_get_tps(state, c);
  }
  
  static int cx22700_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
  {
  	struct cx22700_state* state = fe->demodulator_priv;
  
  	if (enable) {
  		return cx22700_writereg(state, 0x0a, 0x00);
  	} else {
  		return cx22700_writereg(state, 0x0a, 0x01);
  	}
  }
  
  static int cx22700_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings* fesettings)
  {
  	fesettings->min_delay_ms = 150;
  	fesettings->step_size = 166667;
  	fesettings->max_drift = 166667*2;
  	return 0;
  }
  
  static void cx22700_release(struct dvb_frontend* fe)
  {
  	struct cx22700_state* state = fe->demodulator_priv;
  	kfree(state);
  }
  
  static struct dvb_frontend_ops cx22700_ops;
  
  struct dvb_frontend* cx22700_attach(const struct cx22700_config* config,
  				    struct i2c_adapter* i2c)
  {
  	struct cx22700_state* state = NULL;
  
  	/* allocate memory for the internal state */
  	state = kzalloc(sizeof(struct cx22700_state), GFP_KERNEL);
  	if (state == NULL) goto error;
  
  	/* setup the state */
  	state->config = config;
  	state->i2c = i2c;
  
  	/* check if the demod is there */
  	if (cx22700_readreg(state, 0x07) < 0) goto error;
  
  	/* create dvb_frontend */
  	memcpy(&state->frontend.ops, &cx22700_ops, sizeof(struct dvb_frontend_ops));
  	state->frontend.demodulator_priv = state;
  	return &state->frontend;
  
  error:
  	kfree(state);
  	return NULL;
  }
  
  static struct dvb_frontend_ops cx22700_ops = {
  	.delsys = { SYS_DVBT },
  	.info = {
  		.name			= "Conexant CX22700 DVB-T",
  		.frequency_min		= 470000000,
  		.frequency_max		= 860000000,
  		.frequency_stepsize	= 166667,
  		.caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
  		      FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
  		      FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_QAM_64 |
  		      FE_CAN_RECOVER
  	},
  
  	.release = cx22700_release,
  
  	.init = cx22700_init,
  	.i2c_gate_ctrl = cx22700_i2c_gate_ctrl,
  
  	.set_frontend = cx22700_set_frontend,
  	.get_frontend = cx22700_get_frontend,
  	.get_tune_settings = cx22700_get_tune_settings,
  
  	.read_status = cx22700_read_status,
  	.read_ber = cx22700_read_ber,
  	.read_signal_strength = cx22700_read_signal_strength,
  	.read_snr = cx22700_read_snr,
  	.read_ucblocks = cx22700_read_ucblocks,
  };
  
  module_param(debug, int, 0644);
  MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
  
  MODULE_DESCRIPTION("Conexant CX22700 DVB-T Demodulator driver");
  MODULE_AUTHOR("Holger Waechtler");
  MODULE_LICENSE("GPL");
  
  EXPORT_SYMBOL(cx22700_attach);