/*
    Driver for STV0297 demodulator

    Copyright (C) 2003-2004 Dennis Noermann <dennis.noermann@noernet.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/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/delay.h>

#include "dvb_frontend.h"
#include "stv0297.h"

struct stv0297_state {

	struct i2c_adapter* i2c;

	struct dvb_frontend_ops ops;

	const struct stv0297_config* config;

	struct dvb_frontend frontend;
};

#if 0
#define dprintk(x...) printk(x)
#else
#define dprintk(x...)
#endif

#define STV0297_CLOCK   28900

static u8 init_tab [] = {
	0x80, 0x01, /* soft_reset */
	0x80, 0x00, /* cleared soft_reset */
	0x81, 0x01, /* deinterleaver descrambler reset */
	0x81, 0x00, /* cleared deinterleaver descrambler reset */
	0x83, 0x10, /* the Reed-Solomon block reset*/ 
	0x83, 0x00, /* cleared the Reed-Solomon block reset */
	0x84, 0x2b, /* clears the equalizer and also reinitializes the Reg. 00through 04. */
	0x84, 0x2a, /* cleares it .. */
	0x03, 0x00,
	0x25, 0x88,
	0x30, 0x97, 
	0x31, 0x4C,
	0x32, 0xFF,
	0x33, 0x55,
	0x34, 0x00,
	0x35, 0x65,
	0x36, 0x80,
	0x40, 0x1C, 
	0x42, 0x3C, 
	0x43, 0x00,
	0x52, 0x28,
	0x5A, 0x1E,
	0x5B, 0x05,
	0x62, 0x06, 
	0x6A, 0x02, 
	0x70, 0xFF,
	0x71, 0x84,
	0x83, 0x10, 
	0x84, 0x25,
	0x85, 0x00,
	0x86, 0x78,
	0x87, 0x73,
	0x88, 0x08,
	0x89, 0x00,
	0x90, 0x05,
	0xA0, 0x00,
	0xB0, 0x91,
	0xB1, 0x0B, 
	0xC0, 0x4B,
	0xC1, 0x01,
	0xC2, 0x00,
	0xDE, 0x00,
	0xDF, 0x03,
	0x87, 0x73
};


static int stv0297_writereg (struct stv0297_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) 
		dprintk("%s: writereg error (reg == 0x%02x, val == 0x%02x, "
			"ret == %i)\n", __FUNCTION__, reg, data, ret);

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

static int stv0297_writeregs (struct stv0297_state* state, u8 *data, int len)
{
        int ret;
        struct i2c_msg msg = { .addr = state->config->demod_address, .flags = 0, .buf = data, .len = len };
        
        ret = i2c_transfer (state->i2c, &msg, 1);
                
        if (ret != 1)
                dprintk("%s: writeregs error\n ", __FUNCTION__);

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

static u8 stv0297_readreg (struct stv0297_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)
		dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n",
				__FUNCTION__, reg, ret);

        return b1[0];
}

static int stv0297_readregs (struct stv0297_state* state, u8 reg1, u8 *b, u8 len)
{
	int ret;
	struct i2c_msg msg [] = { { .addr = state->config->demod_address, .flags = 0, .buf = &reg1, .len = 1 },
			   { .addr = state->config->demod_address, .flags = I2C_M_RD, .buf = b, .len = len } };

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

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

	return ret == 2 ? 0 : ret;
}

static int stv0297_set_symbolrate (struct stv0297_state* state, u32 srate) 
{
/*
	Betanova sniff : 690000 
	stv0297_writereg (i2c, 0x55, 0x4E);
	stv0297_writereg (i2c, 0x56, 0x00);
	stv0297_writereg (i2c, 0x57, 0x1F);
	stv0297_writereg (i2c, 0x58, 0x3D);
*/
	long tmp, ExtClk;

        ExtClk = (long)(STV0297_CLOCK) / 4;	/* 1/4 = 2^-2 */
	tmp = 131072L * srate;			/* 131072 = 2^17  */
        tmp = tmp /ExtClk;
        tmp = tmp * 8192L;			/* 8192 = 2^13 */

        stv0297_writereg (state, 0x55,(unsigned char)(tmp & 0xFF));  
        stv0297_writereg (state, 0x56,(unsigned char)(tmp>> 8));     
        stv0297_writereg (state, 0x57,(unsigned char)(tmp>>16));     
        stv0297_writereg (state, 0x58,(unsigned char)(tmp>>24));     
 
	return 0;
}

void stv0297_set_sweeprate(struct stv0297_state* state, short _FShift, long _SymbolRate)
{
	long  long_tmp;
	short FShift ;
	unsigned char carrier;
	int   RegSymbolRate;

        FShift = _FShift;  /* in mS .. +/- 5,100 S von 6975 S */
        RegSymbolRate = _SymbolRate;     //RegGetSRate() ;  /* in KHz */
        if(RegSymbolRate <= 0) return ;

        long_tmp = (long)FShift * 262144L ;  // 262144 = 2*18
        long_tmp /= RegSymbolRate ;
        long_tmp *= 1024 ;                   // 1024 = 2*10

        if(long_tmp >= 0)
              long_tmp += 500000 ;
        else  long_tmp -= 500000 ;
        long_tmp /= 1000000 ;

        stv0297_writereg (state, 0x60,(unsigned char)(long_tmp & 0xFF));

        carrier = stv0297_readreg(state, 0x69) & ~ 0xF0;       
        carrier |= (unsigned char)((long_tmp>>4) & 0xF0);   
        stv0297_writereg (state, 0x69, carrier);               

        return;
}

void stv0297_set_frequencyoffset(struct stv0297_state* state, long _CarrierOffset)
{
	long long_tmp;
	unsigned char sweep;

        long_tmp = _CarrierOffset * 26844L ; /* (2**28)/10000 */
        if(long_tmp < 0) long_tmp += 0x10000000 ;
        long_tmp &= 0x0FFFFFFF ;

        stv0297_writereg (state,0x66,(unsigned char)(long_tmp & 0xFF));    // iphase0
        stv0297_writereg (state,0x67,(unsigned char)(long_tmp>>8));        // iphase1
        stv0297_writereg (state,0x68,(unsigned char)(long_tmp>>16));       // iphase2

        sweep = stv0297_readreg(state,0x69) & 0xF0;          
        sweep |= ((unsigned char)(long_tmp>>24) &  0x0F);  
        stv0297_writereg (state,0x69,sweep);                 

        return;
}














static int stv0297_init (struct dvb_frontend* fe)
{
        struct stv0297_state* state = (struct stv0297_state*) fe->demodulator_priv;
	int i;

	dprintk("stv0297: init chip\n");

	for (i=0; i<sizeof(init_tab); i+=2) {
		stv0297_writereg (state, init_tab[i], init_tab[i+1]);
	}

	return 0;
}

static int stv0297_read_status(struct dvb_frontend* fe, fe_status_t* status)
{
        struct stv0297_state* state = (struct stv0297_state*) fe->demodulator_priv;

	u8 sync = stv0297_readreg (state, 0xDF);
		
	*status = 0;
	if (sync & 0x80)
		*status |= FE_HAS_SYNC | FE_HAS_SIGNAL;
	if (sync & 0x80)
		*status |= FE_HAS_CARRIER; 
	if (sync & 0x80)
		*status |= FE_HAS_VITERBI;
	if (sync & 0x80)
		*status |= FE_HAS_LOCK;
	return 0;
}

static int stv0297_read_ber(struct dvb_frontend* fe, u32* ber)
{
        struct stv0297_state* state = (struct stv0297_state*) fe->demodulator_priv;
	u8 BER[3];

	stv0297_writereg (state, 0xA0, 0x80);	// Start Counting bit errors for 4096 Bytes 		
	mdelay(25);				// Hopefully got 4096 Bytes
	stv0297_readregs (state, 0xA0, BER, 3);
	mdelay(25);
	*ber = (BER[2] << 8 | BER[1]) / ( 8 * 4096);

	return 0;
}


static int stv0297_read_signal_strength(struct dvb_frontend* fe, u16* strength)
{
        struct stv0297_state* state = (struct stv0297_state*) fe->demodulator_priv;
	u8 STRENGTH[2];

	mdelay(25);
	stv0297_readregs (state, 0x41, STRENGTH, 2);
	*strength = (STRENGTH[1] & 0x03) << 8 | STRENGTH[0];

	return 0;
}

static int stv0297_read_snr(struct dvb_frontend* fe, u16* snr)
{
        struct stv0297_state* state = (struct stv0297_state*) fe->demodulator_priv;
	u8 SNR[2];

	mdelay(25);
	stv0297_readregs (state, 0x07, SNR, 2);
	*snr = SNR[1] << 8 | SNR[0];

	return 0;
}

static int stv0297_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
{
        struct stv0297_state* state = (struct stv0297_state*) fe->demodulator_priv;

	*ucblocks = (stv0297_readreg (state, 0xD5) << 8)
                   | stv0297_readreg (state, 0xD4);

	return 0;
}

static int stv0297_set_frontend(struct dvb_frontend* fe, struct dvb_frontend_parameters * p)
{
        struct stv0297_state* state = (struct stv0297_state*) fe->demodulator_priv;
	u8 buf2[] = { 0x83, 0x10, 0x25, 0x00, 0x78, 0x73 };
	u8 buf3[] = { 0xC0, 0x4B, 0x01, 0x00 };
	int CarrierOffset = -500;
	int SweepRate = 1380;
	int SpectrumInversion = 0;
        	
	if (SpectrumInversion) {
		SweepRate     = -SweepRate ;
		CarrierOffset = -CarrierOffset ;
       	}
	else {
		SweepRate     = SweepRate ;
		CarrierOffset = CarrierOffset ;
	}

        stv0297_writereg(state, 0x86, 0xF8);
	state->config->pll_set(fe, p);
		
	stv0297_writeregs (state, buf2, sizeof(buf2)); 
	stv0297_writereg (state, 0x84, 0x24); 
	stv0297_writeregs (state, buf3, sizeof(buf3)); 
	stv0297_writereg (state, 0x88, 0x08); 
	stv0297_writereg (state, 0x90, 0x01); 
	stv0297_writereg (state, 0x37, 0x20); 		
	stv0297_writereg (state, 0x40, 0x19); 		
	stv0297_writereg (state, 0x43, 0x40); 
	stv0297_writereg (state, 0x41, 0xE4); 
	stv0297_writereg (state, 0x42, 0x3C); 
	stv0297_writereg (state, 0x44, 0xFF); 
	stv0297_writereg (state, 0x49, 0x04); 
	stv0297_writereg (state, 0x4A, 0xFF); 
	stv0297_writereg (state, 0x4B, 0xFF); 
	stv0297_writereg (state, 0x71, 0x04); 
	stv0297_writereg (state, 0x53, 0x08); 
	stv0297_writereg (state, 0x5A, 0x3E);  //3E forces the direct path to be immediately 
	stv0297_writereg (state, 0x5B, 0x07); 
	stv0297_writereg (state, 0x5B, 0x05); 

	stv0297_set_symbolrate (state, p->u.qam.symbol_rate/1000); 
	stv0297_writereg (state, 0x59, 0x08); 
	stv0297_writereg (state, 0x61, 0x49); 
	stv0297_writereg (state, 0x62, 0x0E); 
	stv0297_writereg (state, 0x6A, 0x02); 
	stv0297_writereg (state, 0x00, 0x48);  // set qam-64

	stv0297_writereg (state, 0x01, 0x58); 
	stv0297_writereg (state, 0x82, 0x00); 
	stv0297_writereg (state, 0x83, 0x08); 
	stv0297_set_sweeprate(state,SweepRate,  p->u.qam.symbol_rate/1000);
	stv0297_writereg (state, 0x20, 0x00); 
	stv0297_writereg (state, 0x21, 0x40); 
	stv0297_set_frequencyoffset(state,CarrierOffset);

	stv0297_writereg (state, 0x82, 0x00); 
	stv0297_writereg (state, 0x85, 0x04); 
	stv0297_writereg (state, 0x43, 0x10); 
	stv0297_writereg (state, 0x5A, 0x5E); 

	stv0297_writereg (state, 0x6A, 0x03); 
		
	stv0297_writereg (state, 0x85, 0x04); 
	stv0297_writereg (state, 0x6B, 0x00); 
	stv0297_writereg (state, 0x4A, 0xFF); 
	stv0297_writereg (state, 0x61, 0x49); 
	stv0297_writereg (state, 0x62, 0x0E); 
	stv0297_writereg (state, 0xDF, 0x02);
	stv0297_writereg (state, 0xDF, 0x01);

	stv0297_writereg (state, 0xDF, 0x02);
	stv0297_writereg (state, 0xDF, 0x01);
				
	stv0297_writereg (state, 0xDF, 0x02); 
	stv0297_writereg (state, 0xDF, 0x01);

	return 0;
}

static void stv0297_release(struct dvb_frontend* fe)
{
	struct stv0297_state* state = (struct stv0297_state*) fe->demodulator_priv;
	kfree(state);
}

static struct dvb_frontend_ops stv0297_ops;

struct dvb_frontend* stv0297_attach(const struct stv0297_config* config,
				    struct i2c_adapter* i2c)
{
	struct stv0297_state* state = NULL;
	int id;

	/* allocate memory for the internal state */
	state = (struct stv0297_state*) kmalloc(sizeof(struct stv0297_state), GFP_KERNEL);
	if (state == NULL) goto error;

	/* setup the state */
	state->config = config;
	state->i2c = i2c;
	memcpy(&state->ops, &stv0297_ops, sizeof(struct dvb_frontend_ops));

	/* check if the demod is there */
	stv0297_writereg(state, 0x02, 0x34); /* standby off */
	msleep(200);
	id = stv0297_readreg(state, 0x00);

	/* register 0x00 contains 0xa1 for STV0299 and STV0299B */
	/* register 0x00 might contain 0x80 when returning from standby */
	if (id != 0xa1 && id != 0x80) goto error;

	/* create dvb_frontend */
	state->frontend.ops = &state->ops;
        state->frontend.demodulator_priv = state;
	return &state->frontend;

error:
	if (state) kfree(state);
	return NULL;
}

static struct dvb_frontend_ops stv0297_ops = {

	.info = {
		.name			= "ST STV0297 DVB-C",
		.type			= FE_QAM,
		.frequency_min		= 64000000,
		.frequency_max		= 1300000000,
		.frequency_stepsize	= 62500,
		.symbol_rate_min	= 870000,
		.symbol_rate_max	= 11700000,
		.caps = FE_CAN_QAM_16 | FE_CAN_QAM_32 | FE_CAN_QAM_64 |
			FE_CAN_QAM_128 | FE_CAN_QAM_256 |
			FE_CAN_FEC_AUTO | FE_CAN_INVERSION_AUTO |
			FE_CAN_RECOVER
	},

	.release = stv0297_release,

	.init = stv0297_init,

	.set_frontend = stv0297_set_frontend,

	.read_status = stv0297_read_status,
	.read_ber = stv0297_read_ber,
	.read_signal_strength = stv0297_read_signal_strength,
	.read_snr = stv0297_read_snr,
	.read_ucblocks = stv0297_read_ucblocks,
};

MODULE_DESCRIPTION("ST STV0297 DVB-C Demodulator driver");
MODULE_AUTHOR("Dennis Noermann");
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(stv0297_attach);