/*
    Conexant 22702 DVB OFDM demodulator driver

    based on:
	Alps TDMB7 DVB OFDM demodulator driver

    Copyright (C) 2001-2002 Convergence Integrated Media GmbH
	  Holger Waechtler <holger@convergence.de>

    Copyright (C) 2004 Steven Toth <stoth@hauppauge.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/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include "dvb_frontend.h"
#include "cx22702.h"


struct cx22702_state {

	struct i2c_adapter* i2c;

	/* configuration settings */
	const struct cx22702_config* config;

	struct dvb_frontend frontend;

	/* previous uncorrected block counter */
	u8 prevUCBlocks;
};

static int debug;
#define dprintk	if (debug) printk

/* Register values to initialise the demod */
static u8 init_tab [] = {
	0x00, 0x00, /* Stop aquisition */
	0x0B, 0x06,
	0x09, 0x01,
	0x0D, 0x41,
	0x16, 0x32,
	0x20, 0x0A,
	0x21, 0x17,
	0x24, 0x3e,
	0x26, 0xff,
	0x27, 0x10,
	0x28, 0x00,
	0x29, 0x00,
	0x2a, 0x10,
	0x2b, 0x00,
	0x2c, 0x10,
	0x2d, 0x00,
	0x48, 0xd4,
	0x49, 0x56,
	0x6b, 0x1e,
	0xc8, 0x02,
	0xf9, 0x00,
	0xfa, 0x00,
	0xfb, 0x00,
	0xfc, 0x00,
	0xfd, 0x00,
};

static int cx22702_writereg (struct cx22702_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 };

	ret = i2c_transfer(state->i2c, &msg, 1);

	if (ret != 1)
		printk("%s: writereg error (reg == 0x%02x, val == 0x%02x, ret == %i)\n",
			__func__, reg, data, ret);

	return (ret != 1) ? -1 : 0;
}

static u8 cx22702_readreg (struct cx22702_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 } };

	ret = i2c_transfer(state->i2c, msg, 2);

	if (ret != 2)
		printk("%s: readreg error (ret == %i)\n", __func__, ret);

	return b1[0];
}

static int cx22702_set_inversion (struct cx22702_state *state, int inversion)
{
	u8 val;

	switch (inversion) {

		case INVERSION_AUTO:
			return -EOPNOTSUPP;

		case INVERSION_ON:
			val = cx22702_readreg (state, 0x0C);
			return cx22702_writereg (state, 0x0C, val | 0x01);

		case INVERSION_OFF:
			val = cx22702_readreg (state, 0x0C);
			return cx22702_writereg (state, 0x0C, val & 0xfe);

		default:
			return -EINVAL;

	}

}

/* Retrieve the demod settings */
static int cx22702_get_tps (struct cx22702_state *state, struct dvb_ofdm_parameters *p)
{
	u8 val;

	/* Make sure the TPS regs are valid */
	if (!(cx22702_readreg(state, 0x0A) & 0x20))
		return -EAGAIN;

	val = cx22702_readreg (state, 0x01);
	switch( (val&0x18)>>3) {
		case 0: p->constellation =   QPSK; break;
		case 1: p->constellation = QAM_16; break;
		case 2: p->constellation = QAM_64; break;
	}
	switch( val&0x07 ) {
		case 0: p->hierarchy_information = HIERARCHY_NONE; break;
		case 1: p->hierarchy_information =    HIERARCHY_1; break;
		case 2: p->hierarchy_information =    HIERARCHY_2; break;
		case 3: p->hierarchy_information =    HIERARCHY_4; break;
	}


	val = cx22702_readreg (state, 0x02);
	switch( (val&0x38)>>3 ) {
		case 0: p->code_rate_HP = FEC_1_2; break;
		case 1: p->code_rate_HP = FEC_2_3; break;
		case 2: p->code_rate_HP = FEC_3_4; break;
		case 3: p->code_rate_HP = FEC_5_6; break;
		case 4: p->code_rate_HP = FEC_7_8; break;
	}
	switch( val&0x07 ) {
		case 0: p->code_rate_LP = FEC_1_2; break;
		case 1: p->code_rate_LP = FEC_2_3; break;
		case 2: p->code_rate_LP = FEC_3_4; break;
		case 3: p->code_rate_LP = FEC_5_6; break;
		case 4: p->code_rate_LP = FEC_7_8; break;
	}


	val = cx22702_readreg (state, 0x03);
	switch( (val&0x0c)>>2 ) {
		case 0: p->guard_interval = GUARD_INTERVAL_1_32; break;
		case 1: p->guard_interval = GUARD_INTERVAL_1_16; break;
		case 2: p->guard_interval =  GUARD_INTERVAL_1_8; break;
		case 3: p->guard_interval =  GUARD_INTERVAL_1_4; break;
	}
	switch( val&0x03 ) {
		case 0: p->transmission_mode = TRANSMISSION_MODE_2K; break;
		case 1: p->transmission_mode = TRANSMISSION_MODE_8K; break;
	}

	return 0;
}

static int cx22702_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
{
	struct cx22702_state* state = fe->demodulator_priv;
	dprintk ("%s(%d)\n", __func__, enable);
	if (enable)
		return cx22702_writereg (state, 0x0D, cx22702_readreg(state, 0x0D) & 0xfe);
	else
		return cx22702_writereg (state, 0x0D, cx22702_readreg(state, 0x0D) | 1);
}

/* Talk to the demod, set the FEC, GUARD, QAM settings etc */
static int cx22702_set_tps (struct dvb_frontend* fe, struct dvb_frontend_parameters *p)
{
	u8 val;
	struct cx22702_state* state = fe->demodulator_priv;

	if (fe->ops.tuner_ops.set_params) {
		fe->ops.tuner_ops.set_params(fe, p);
		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
	}

	/* set inversion */
	cx22702_set_inversion (state, p->inversion);

	/* set bandwidth */
	switch(p->u.ofdm.bandwidth) {
	case BANDWIDTH_6_MHZ:
		cx22702_writereg(state, 0x0C, (cx22702_readreg(state, 0x0C) & 0xcf) | 0x20 );
		break;
	case BANDWIDTH_7_MHZ:
		cx22702_writereg(state, 0x0C, (cx22702_readreg(state, 0x0C) & 0xcf) | 0x10 );
		break;
	case BANDWIDTH_8_MHZ:
		cx22702_writereg(state, 0x0C, cx22702_readreg(state, 0x0C) &0xcf );
		break;
	default:
		dprintk ("%s: invalid bandwidth\n",__func__);
		return -EINVAL;
	}


	p->u.ofdm.code_rate_LP = FEC_AUTO; //temp hack as manual not working

	/* use auto configuration? */
	if((p->u.ofdm.hierarchy_information==HIERARCHY_AUTO) ||
	   (p->u.ofdm.constellation==QAM_AUTO) ||
	   (p->u.ofdm.code_rate_HP==FEC_AUTO) ||
	   (p->u.ofdm.code_rate_LP==FEC_AUTO) ||
	   (p->u.ofdm.guard_interval==GUARD_INTERVAL_AUTO) ||
	   (p->u.ofdm.transmission_mode==TRANSMISSION_MODE_AUTO) ) {

		/* TPS Source - use hardware driven values */
		cx22702_writereg(state, 0x06, 0x10);
		cx22702_writereg(state, 0x07, 0x9);
		cx22702_writereg(state, 0x08, 0xC1);
		cx22702_writereg(state, 0x0B, cx22702_readreg(state, 0x0B) & 0xfc );
		cx22702_writereg(state, 0x0C, (cx22702_readreg(state, 0x0C) & 0xBF) | 0x40 );
		cx22702_writereg(state, 0x00, 0x01); /* Begin aquisition */
		dprintk("%s: Autodetecting\n",__func__);
		return 0;
	}

	/* manually programmed values */
	val=0;
	switch(p->u.ofdm.constellation) {
		case   QPSK: val = (val&0xe7); break;
		case QAM_16: val = (val&0xe7)|0x08; break;
		case QAM_64: val = (val&0xe7)|0x10; break;
		default:
			dprintk ("%s: invalid constellation\n",__func__);
			return -EINVAL;
	}
	switch(p->u.ofdm.hierarchy_information) {
		case HIERARCHY_NONE: val = (val&0xf8); break;
		case    HIERARCHY_1: val = (val&0xf8)|1; break;
		case    HIERARCHY_2: val = (val&0xf8)|2; break;
		case    HIERARCHY_4: val = (val&0xf8)|3; break;
		default:
			dprintk ("%s: invalid hierarchy\n",__func__);
			return -EINVAL;
	}
	cx22702_writereg (state, 0x06, val);

	val=0;
	switch(p->u.ofdm.code_rate_HP) {
		case FEC_NONE:
		case FEC_1_2: val = (val&0xc7); break;
		case FEC_2_3: val = (val&0xc7)|0x08; break;
		case FEC_3_4: val = (val&0xc7)|0x10; break;
		case FEC_5_6: val = (val&0xc7)|0x18; break;
		case FEC_7_8: val = (val&0xc7)|0x20; break;
		default:
			dprintk ("%s: invalid code_rate_HP\n",__func__);
			return -EINVAL;
	}
	switch(p->u.ofdm.code_rate_LP) {
		case FEC_NONE:
		case FEC_1_2: val = (val&0xf8); break;
		case FEC_2_3: val = (val&0xf8)|1; break;
		case FEC_3_4: val = (val&0xf8)|2; break;
		case FEC_5_6: val = (val&0xf8)|3; break;
		case FEC_7_8: val = (val&0xf8)|4; break;
		default:
			dprintk ("%s: invalid code_rate_LP\n",__func__);
			return -EINVAL;
	}
	cx22702_writereg (state, 0x07, val);

	val=0;
	switch(p->u.ofdm.guard_interval) {
		case GUARD_INTERVAL_1_32: val = (val&0xf3); break;
		case GUARD_INTERVAL_1_16: val = (val&0xf3)|0x04; break;
		case  GUARD_INTERVAL_1_8: val = (val&0xf3)|0x08; break;
		case  GUARD_INTERVAL_1_4: val = (val&0xf3)|0x0c; break;
		default:
			dprintk ("%s: invalid guard_interval\n",__func__);
			return -EINVAL;
	}
	switch(p->u.ofdm.transmission_mode) {
		case TRANSMISSION_MODE_2K: val = (val&0xfc); break;
		case TRANSMISSION_MODE_8K: val = (val&0xfc)|1; break;
		default:
			dprintk ("%s: invalid transmission_mode\n",__func__);
			return -EINVAL;
	}
	cx22702_writereg(state, 0x08, val);
	cx22702_writereg(state, 0x0B, (cx22702_readreg(state, 0x0B) & 0xfc) | 0x02 );
	cx22702_writereg(state, 0x0C, (cx22702_readreg(state, 0x0C) & 0xBF) | 0x40 );

	/* Begin channel aquisition */
	cx22702_writereg(state, 0x00, 0x01);

	return 0;
}

/* Reset the demod hardware and reset all of the configuration registers
   to a default state. */
static int cx22702_init (struct dvb_frontend* fe)
{
	int i;
	struct cx22702_state* state = fe->demodulator_priv;

	cx22702_writereg (state, 0x00, 0x02);

	msleep(10);

	for (i=0; i<sizeof(init_tab); i+=2)
		cx22702_writereg (state, init_tab[i], init_tab[i+1]);

	cx22702_writereg (state, 0xf8, (state->config->output_mode << 1) & 0x02);

	cx22702_i2c_gate_ctrl(fe, 0);

	return 0;
}

static int cx22702_read_status(struct dvb_frontend* fe, fe_status_t* status)
{
	struct cx22702_state* state = fe->demodulator_priv;
	u8 reg0A;
	u8 reg23;

	*status = 0;

	reg0A = cx22702_readreg (state, 0x0A);
	reg23 = cx22702_readreg (state, 0x23);

	dprintk ("%s: status demod=0x%02x agc=0x%02x\n"
		,__func__,reg0A,reg23);

	if(reg0A & 0x10) {
		*status |= FE_HAS_LOCK;
		*status |= FE_HAS_VITERBI;
		*status |= FE_HAS_SYNC;
	}

	if(reg0A & 0x20)
		*status |= FE_HAS_CARRIER;

	if(reg23 < 0xf0)
		*status |= FE_HAS_SIGNAL;

	return 0;
}

static int cx22702_read_ber(struct dvb_frontend* fe, u32* ber)
{
	struct cx22702_state* state = fe->demodulator_priv;

	if(cx22702_readreg (state, 0xE4) & 0x02) {
		/* Realtime statistics */
		*ber = (cx22702_readreg (state, 0xDE) & 0x7F) << 7
			| (cx22702_readreg (state, 0xDF)&0x7F);
	} else {
		/* Averagtine statistics */
		*ber = (cx22702_readreg (state, 0xDE) & 0x7F) << 7
			| cx22702_readreg (state, 0xDF);
	}

	return 0;
}

static int cx22702_read_signal_strength(struct dvb_frontend* fe, u16* signal_strength)
{
	struct cx22702_state* state = fe->demodulator_priv;

	u16 rs_ber = 0;
	rs_ber = cx22702_readreg (state, 0x23);
	*signal_strength = (rs_ber << 8) | rs_ber;

	return 0;
}

static int cx22702_read_snr(struct dvb_frontend* fe, u16* snr)
{
	struct cx22702_state* state = fe->demodulator_priv;

	u16 rs_ber=0;
	if(cx22702_readreg (state, 0xE4) & 0x02) {
		/* Realtime statistics */
		rs_ber = (cx22702_readreg (state, 0xDE) & 0x7F) << 7
			| (cx22702_readreg (state, 0xDF)& 0x7F);
	} else {
		/* Averagine statistics */
		rs_ber = (cx22702_readreg (state, 0xDE) & 0x7F) << 8
			| cx22702_readreg (state, 0xDF);
	}
	*snr = ~rs_ber;

	return 0;
}

static int cx22702_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
{
	struct cx22702_state* state = fe->demodulator_priv;

	u8 _ucblocks;

	/* RS Uncorrectable Packet Count then reset */
	_ucblocks = cx22702_readreg (state, 0xE3);
	if (state->prevUCBlocks < _ucblocks)
		*ucblocks = (_ucblocks - state->prevUCBlocks);
	else
		*ucblocks = state->prevUCBlocks - _ucblocks;
	state->prevUCBlocks = _ucblocks;

	return 0;
}

static int cx22702_get_frontend(struct dvb_frontend* fe, struct dvb_frontend_parameters *p)
{
	struct cx22702_state* state = fe->demodulator_priv;

	u8 reg0C = cx22702_readreg (state, 0x0C);

	p->inversion = reg0C & 0x1 ? INVERSION_ON : INVERSION_OFF;
	return cx22702_get_tps (state, &p->u.ofdm);
}

static int cx22702_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings *tune)
{
	tune->min_delay_ms = 1000;
	return 0;
}

static void cx22702_release(struct dvb_frontend* fe)
{
	struct cx22702_state* state = fe->demodulator_priv;
	kfree(state);
}

static struct dvb_frontend_ops cx22702_ops;

struct dvb_frontend* cx22702_attach(const struct cx22702_config* config,
				    struct i2c_adapter* i2c)
{
	struct cx22702_state* state = NULL;

	/* allocate memory for the internal state */
	state = kmalloc(sizeof(struct cx22702_state), GFP_KERNEL);
	if (state == NULL)
		goto error;

	/* setup the state */
	state->config = config;
	state->i2c = i2c;
	state->prevUCBlocks = 0;

	/* check if the demod is there */
	if (cx22702_readreg(state, 0x1f) != 0x3)
		goto error;

	/* create dvb_frontend */
	memcpy(&state->frontend.ops, &cx22702_ops, sizeof(struct dvb_frontend_ops));
	state->frontend.demodulator_priv = state;
	return &state->frontend;

error:
	kfree(state);
	return NULL;
}

static struct dvb_frontend_ops cx22702_ops = {

	.info = {
		.name			= "Conexant CX22702 DVB-T",
		.type			= FE_OFDM,
		.frequency_min		= 177000000,
		.frequency_max		= 858000000,
		.frequency_stepsize	= 166666,
		.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_QAM_AUTO |
		FE_CAN_HIERARCHY_AUTO | FE_CAN_GUARD_INTERVAL_AUTO |
		FE_CAN_TRANSMISSION_MODE_AUTO | FE_CAN_RECOVER
	},

	.release = cx22702_release,

	.init = cx22702_init,
	.i2c_gate_ctrl = cx22702_i2c_gate_ctrl,

	.set_frontend = cx22702_set_tps,
	.get_frontend = cx22702_get_frontend,
	.get_tune_settings = cx22702_get_tune_settings,

	.read_status = cx22702_read_status,
	.read_ber = cx22702_read_ber,
	.read_signal_strength = cx22702_read_signal_strength,
	.read_snr = cx22702_read_snr,
	.read_ucblocks = cx22702_read_ucblocks,
};

module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Enable verbose debug messages");

MODULE_DESCRIPTION("Conexant CX22702 DVB-T Demodulator driver");
MODULE_AUTHOR("Steven Toth");
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(cx22702_attach);