/*
 *  Driver for Zarlink DVB-T MT352 demodulator
 *
 *  Written by Holger Waechtler <holger@qanu.de>
 *	 and Daniel Mack <daniel@qanu.de>
 *
 *  AVerMedia AVerTV DVB-T 771 support by
 *       Wolfram Joost <dbox2@frokaschwei.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/module.h>
#include <linux/init.h>
#include <linux/delay.h>

#include "dvb_frontend.h"

#define I2C_MT352_ADDR 0x0f
#define I2C_TUNER_ADDR 0xc2

#define CARD_UNKNOWN	0x00
#define CARD_AVDVBT771	0x01

#define mt352_write(ibuf, ilen)						\
do {									\
	struct i2c_msg msg = { .addr = I2C_MT352_ADDR, .flags = 0,	\
			       .buf = ibuf, .len = ilen };		\
	int err = i2c->xfer(i2c, &msg, 1);				\
	if (err != 1) {							\
		printk(KERN_WARNING 					\
		       "mt352_write() failed (err = %d)!\n", err);	\
		return err;						\
	}								\
} while (0)


#define msb(x) (((x) >> 8) & 0xff)
#define lsb(x) ((x) & 0xff)

static struct dvb_frontend_info mt352_info = {
	.name 			= "DVB-T Zarlink MT352 demodulator driver",
	.type 			= FE_OFDM,
	.frequency_min 		= 174000000, /* NIM of AV771 starts at 50MHz */
	.frequency_max 		= 862000000,
	.frequency_stepsize 	= 83333,
/*
	.frequency_tolerance 	= 0,
	.symbol_rate_min 	= 1000000,
	.symbol_rate_max 	= 45000000,
	.symbol_rate_tolerance 	= ???,
*/
	.notifier_delay		 = 0,
	.caps = FE_CAN_INVERSION_AUTO | 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_TRANSMISSION_MODE_AUTO | FE_CAN_GUARD_INTERVAL_AUTO |
		FE_CAN_HIERARCHY_AUTO | FE_CAN_RECOVER |
		FE_CAN_MUTE_TS
};

int mt352_detect_avermedia_771(struct dvb_i2c_bus *i2c)
{
	u8 reg;
	u8 id[4];
	const u8 pciid[4] = { 0x07, 0x71, 0x14, 0x61 };
	struct i2c_msg msg[2] =
	{
		{
			.addr = 0x50,
			.flags = I2C_M_NOSTART,
			.buf = &reg,
			.len = 1
		},
		{
			.addr = 0x50,
			.flags = I2C_M_RD,
			.len = 1
		}
    };
	int i;

	for (i = 0; i < 4; i++)
	{
		reg = i + 0xFC;
		msg[1].buf = id + i;
		if (i2c->xfer(i2c,msg,2) != 2)
		{
			return 0;
		}
	}

	return *((u32 *) id) == *((u32 *) pciid);
}

int mt352_init (struct dvb_i2c_bus *i2c, u32 card_type)
{
	/**
	 *  all register write sequence have the register address of the
	 *  first register in the first byte, thenafter the value to write
	 *  into this and the following registers.
	 */
	static u8 mt352_reset [] = { 0x50, 0x80 };
	static u8 mt352_clock_config [] = { 0x89, 0x38, 0x2d };
	static u8 mt352_adc_ctl_1_cfg [] = { 0x8e, 0x40 };
	static u8 mt352_agc_cfg [] = { 0x67, 0x19, 0xa0 };
	static u8 mt352_acq_ctl [] = { 0x53, 0x50 };

	static u8 mt352_agc_cfg_av771 [] = { 0x67, 0x10, 0x23, 0x00, 0xFF, 0xFF,
										 0x00, 0xFF, 0x00, 0x40, 0x40 };
	static u8 mt352_av771_extra[] = { 0xB5, 0x7A };
	/**
	 *  We only write non-default settings, all default settings are
	 *  restored by the full mt352_reset sequence.
	 */
	mt352_write(mt352_clock_config, sizeof(mt352_clock_config));
	udelay(2000);
	mt352_write(mt352_reset, sizeof(mt352_reset));
	mt352_write(mt352_adc_ctl_1_cfg, sizeof(mt352_adc_ctl_1_cfg));
	mt352_write(mt352_acq_ctl, sizeof(mt352_acq_ctl));
	if (card_type == CARD_AVDVBT771)
	{
		mt352_write(mt352_agc_cfg_av771,sizeof(mt352_agc_cfg_av771));
		udelay(2000);
		mt352_write(mt352_av771_extra,sizeof(mt352_av771_extra));
	}
	else
	{
		/**
		 *  The optimal AGC target value and slope might vary from tuner
		 *  type to tuner type, so check whether you need to adjust this one...
		 */
		mt352_write(mt352_agc_cfg, sizeof(mt352_agc_cfg));
	}

	return 0;
}

int mt352_sleep(struct dvb_i2c_bus *i2c)
{
	static u8 mt352_softdown[] = { 0x89, 0x20, 0x08 };

	mt352_write(mt352_softdown, sizeof(mt352_softdown));

	return 0;
}

int mt352_set_parameters (struct dvb_i2c_bus *i2c,
			  struct dvb_frontend_parameters *param, u32 card_type)
{
	unsigned char buf[14];
	unsigned int tps = 0;
	struct dvb_ofdm_parameters *op = &param->u.ofdm;
	u32 freq = param->frequency / 1000;
	uint16_t tmp;

	switch (op->code_rate_HP) {
		case FEC_2_3:
			tps = (1 << 7);
			break;
		case FEC_3_4:
			tps = (2 << 7);
			break;
		case FEC_5_6:
			tps = (3 << 7);
			break;
		case FEC_7_8:
			tps = (4 << 7);
			break;
		case FEC_1_2:
		case FEC_AUTO:
			break;
		default:
			return -EINVAL;
	}

	switch (op->code_rate_LP) {
		case FEC_2_3:
			tps |= (1 << 4);
			break;
		case FEC_3_4:
			tps |= (2 << 4);
			break;
		case FEC_5_6:
			tps |= (3 << 4);
			break;
		case FEC_7_8:
			tps |= (4 << 4);
			break;
		case FEC_1_2:
		case FEC_AUTO:
			break;
		default:
			return -EINVAL;
	}

	switch (op->constellation) {
		case QPSK:
			break;
		case QAM_AUTO:
		case QAM_16:
			tps |= (1 << 13);
			break;
		case QAM_64:
			tps |= (2 << 13);
			break;
		default:
			return -EINVAL;
	}

	switch (op->transmission_mode) {
		case TRANSMISSION_MODE_2K:
		case TRANSMISSION_MODE_AUTO:
			break;
		case TRANSMISSION_MODE_8K:
			tps |= (1 << 0);
			break;
		default:
			return -EINVAL;
	}

	switch (op->guard_interval) {
		case GUARD_INTERVAL_1_32:
		case GUARD_INTERVAL_AUTO:
			break;
		case GUARD_INTERVAL_1_16:
			tps |= (1 << 2);
			break;
		case GUARD_INTERVAL_1_8:
			tps |= (2 << 2);
			break;
		case GUARD_INTERVAL_1_4:
			tps |= (3 << 2);
			break;
		default:
			return -EINVAL;
	}

	switch (op->hierarchy_information) {
		case HIERARCHY_AUTO:
		case HIERARCHY_NONE:
			break;
		case HIERARCHY_1:
			tps |= (1 << 10);
			break;
		case HIERARCHY_2:
			tps |= (2 << 10);
			break;
		case HIERARCHY_4:
			tps |= (3 << 10);
			break;
		default:
			return -EINVAL;
	}


	buf[0] = 0x51; /* TPS_GIVEN_1 and following registers */

	buf[1] = msb(tps);      /* TPS_GIVEN_(1|0) */
	buf[2] = lsb(tps);

	buf[3] = 0x50;

	/**
	 *  these settings assume 20.48MHz f_ADC, for other tuners you might
	 *  need other values. See p. 33 in the MT352 Design Manual.
	 */
	if (op->bandwidth == BANDWIDTH_8_MHZ) {
		buf[4] = 0x72;  /* TRL_NOMINAL_RATE_(1|0) */
		buf[5] = 0x49;
	} else if (op->bandwidth == BANDWIDTH_7_MHZ) {
		buf[4] = 0x64;
		buf[5] = 0x00;
	} else {		/* 6MHz */
		buf[4] = 0x55;
		buf[5] = 0xb7;
	}

	buf[8] = I2C_TUNER_ADDR;

	/**
	 *  All the following settings are tuner module dependent,
	 *  check the datasheet...
	 */

	/* here we assume 1/6MHz == 166.66kHz stepsize */
	#define IF_FREQUENCYx6 217    /* 6 * 36.16666666667MHz */
	tmp = (3 * freq) / 500 + IF_FREQUENCYx6;
	buf[9] = msb(tmp);      /* CHAN_START_(1|0) */
	buf[10] = lsb(tmp);

	buf[6] = 0x31;  /* INPUT_FREQ_(1|0), 20.48MHz clock, 36.166667MHz IF */
	buf[7] = 0x05;  /* see MT352 Design Manual page 32 for details */

	if (card_type == CARD_AVDVBT771)
	{
		if (freq < 150000)
		{
			buf[11] = 0xB4;
			buf[12] = 0x01;
		}
		else if (freq < 173000)
		{
			buf[11] = 0xBC;
			buf[12] = 0x01;
		}
		else if (freq < 250000)
		{
			buf[11] = 0xB4;
			buf[12] = 0x02;
		}
		else if (freq < 400000)
		{
			buf[11] = 0xBC;
			buf[12] = 0x02;
		}
		else if (freq < 420000)
		{
			buf[11] = 0xF4;
			buf[12] = 0x02;
		}
		else if (freq < 470000)
		{
			buf[11] = 0xFC;
			buf[12] = 0x02;
		}
		else if (freq < 600000)
		{
			buf[11] = 0xBC;
			buf[12] = 0x08;
		}
		else if (freq < 730000)
		{
			buf[11] = 0xF4;
			buf[12] = 0x08;
		}
		else
		{
			buf[11] = 0xFC;
			buf[12] = 0x08;
		}
	}
	else
	{

		printk (KERN_WARNING "buf9,10: %02x %02x\n", buf[9], buf[10]);

		if (freq < 542000)
			buf[11] = 0xbe; /* CONT_1, charge pump byte */
		else if (freq < 830000)
			buf[11] = 0xf6;
		else
			buf[11] = 0xfe;

		if (freq < 250000)	 /* VHF, freq < 250MHz */
			buf[12] = 0x01; /* CONT_0, bandswitch byte */
		else
			buf[12] = 0x08;
	}

	buf[13] = 0x01; /* TUNER_GO!! */

	mt352_write(buf, sizeof(buf));

	return 0;
}

static u8 mt352_read_register (struct dvb_i2c_bus *i2c, u8 reg)
{
	int ret;
	u8 b0 [] = { reg };
	u8 b1 [] = { 0 };
	struct i2c_msg msg [] = { { .addr = I2C_MT352_ADDR,
				    .flags = I2C_M_NOSTART,
				    .buf = b0, .len = 1 },
				  { .addr = I2C_MT352_ADDR,
				    .flags = I2C_M_RD,
				    .buf = b1, .len = 1 } };

	ret = i2c->xfer (i2c, msg, 2);

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

	return b1[0];
}


int mt352_get_parameters (struct dvb_i2c_bus *i2c,
			  struct dvb_frontend_parameters *param, u32 card_type)
{
	u16 tps;
	u16 div;
	u8 trl;

	struct dvb_ofdm_parameters *op = &param->u.ofdm;
	static const u8 tps_fec_to_api[8] =
	{
		FEC_1_2,
		FEC_2_3,
		FEC_3_4,
		FEC_5_6,
		FEC_7_8,
		FEC_AUTO,
		FEC_AUTO,
		FEC_AUTO
	};

	if ( (mt352_read_register(i2c,0x00) & 0xC0) != 0xC0 )
	{
		return -EINVAL;
	}

	/* Use TPS_RECEIVED-registers, not the TPS_CURRENT-registers because
	 * the mt352 sometimes works with the wrong parameters
	 */
	tps = (mt352_read_register(i2c,0x1E) << 8) | mt352_read_register(i2c,0x1F);
	div = (mt352_read_register(i2c,0x59) << 8) | mt352_read_register(i2c,0x5A);
	trl = mt352_read_register(i2c,0x54);

	op->code_rate_HP = tps_fec_to_api[(tps >> 7) & 7];
	op->code_rate_LP = tps_fec_to_api[(tps >> 4) & 7];

	switch ( (tps >> 13) & 3)
	{
		case 0:
			op->constellation = QPSK;
			break;
		case 1:
			op->constellation = QAM_16;
			break;
		case 2:
			op->constellation = QAM_64;
			break;
		default:
			op->constellation = QAM_AUTO;
			break;
	}

	op->transmission_mode = (tps & 0x01) ? TRANSMISSION_MODE_8K : TRANSMISSION_MODE_2K;

	switch ( (tps >> 2) & 3)
	{
		case 0:
			op->guard_interval = GUARD_INTERVAL_1_32;
			break;
		case 1:
			op->guard_interval = GUARD_INTERVAL_1_16;
			break;
		case 2:
			op->guard_interval = GUARD_INTERVAL_1_8;
			break;
		case 3:
			op->guard_interval = GUARD_INTERVAL_1_4;
			break;
		default:
			op->guard_interval = GUARD_INTERVAL_AUTO;
			break;
	}

	switch ( (tps >> 10) & 7)
	{
		case 0:
			op->hierarchy_information = HIERARCHY_NONE;
			break;
		case 1:
			op->hierarchy_information = HIERARCHY_1;
			break;
		case 2:
			op->hierarchy_information = HIERARCHY_2;
			break;
		case 3:
			op->hierarchy_information = HIERARCHY_4;
			break;
		default:
			op->hierarchy_information = HIERARCHY_AUTO;
			break;
	}

	param->frequency = ( 500 * (div - IF_FREQUENCYx6) ) / 3 * 1000;

	if (trl == 0x72)
	{
		op->bandwidth = BANDWIDTH_8_MHZ;
	}
	else if (trl == 0x64)
	{
		op->bandwidth = BANDWIDTH_7_MHZ;
	}
	else
	{
		op->bandwidth = BANDWIDTH_6_MHZ;
	}

	param->inversion = INVERSION_OFF;

	return 0;
}


static int mt352_ioctl (struct dvb_frontend *fe, unsigned int cmd, void *arg)
{
	struct dvb_i2c_bus *i2c = fe->i2c;
	u32 card_type = (u32) fe->data;
	u8 r,snr;
	fe_status_t *status;
	u16 signal;
#ifdef FE_GET_TUNE_SETTINGS
	struct dvb_frontend_tune_settings* fe_tune_settings;
#endif

	switch (cmd) {
	case FE_GET_INFO:
		memcpy (arg, &mt352_info, sizeof(struct dvb_frontend_info));
		break;

	case FE_READ_STATUS:
		status = arg;
		*status = 0;
		r = mt352_read_register (i2c, 0x00);
		if (r & (1 << 4))
			*status = FE_HAS_CARRIER;
		if (r & (1 << 1))
			*status |= FE_HAS_VITERBI;
		if (r & (1 << 5))
			*status |= FE_HAS_LOCK;

		r = mt352_read_register (i2c, 0x01);
		if (r & (1 << 1))
			*status |= FE_HAS_SYNC;

		r = mt352_read_register (i2c, 0x03);
		if (r & (1 << 6))
			*status |= FE_HAS_SIGNAL;

		break;

	case FE_READ_BER:
		*((u32 *) arg) = (mt352_read_register (i2c, 0x0D) << 16) |
		       (mt352_read_register (i2c, 0x0E) << 8) |
		       (mt352_read_register (i2c, 0x0F));
		break;

	case FE_READ_SIGNAL_STRENGTH:
		signal = (mt352_read_register (i2c, 0x12) << 8) |
			     (mt352_read_register (i2c, 0x13));
		*((u16*) arg) = ~signal;
		break;

	case FE_READ_SNR:
		snr = mt352_read_register (i2c, 0x09);
		*((u16*) arg) = (snr << 8) | snr;
		break;

	case FE_READ_UNCORRECTED_BLOCKS:
		*(u32*) arg = (mt352_read_register (i2c, 0x10) << 8) |
			      (mt352_read_register (i2c, 0x11));
		break;

	case FE_SET_FRONTEND:
		return mt352_set_parameters (i2c,
				 (struct dvb_frontend_parameters *) arg,card_type);

	case FE_GET_FRONTEND:
		return mt352_get_parameters (i2c,
				 (struct dvb_frontend_parameters *) arg,card_type);

#ifdef FE_GET_TUNE_SETTINGS
	case FE_GET_TUNE_SETTINGS:
		fe_tune_settings = (struct dvb_frontend_tune_settings*) arg;
		fe_tune_settings->min_delay_ms = 50;
		fe_tune_settings->step_size = mt352_info.frequency_stepsize;
		fe_tune_settings->max_drift = mt352_info.frequency_stepsize*2;
#endif

	case FE_SLEEP:
		return mt352_sleep(i2c);

	case FE_INIT:
		return mt352_init(i2c,card_type);

	default:
		return -EOPNOTSUPP;
	}

	return 0;
}


static int mt352_attach (struct dvb_i2c_bus *i2c, void **data)
{
	u32 card_type;
	static u8 mt352_reset_attach [] = { 0x50, 0xC0 };

	if (mt352_read_register(i2c, 0x7f) == 0x13)
	{
		if (mt352_detect_avermedia_771(i2c))
		{
			card_type = CARD_AVDVBT771;
		}
		else
		{
			card_type = CARD_UNKNOWN;
		}
		/* Do a "hard" reset */
		mt352_write(mt352_reset_attach,sizeof(mt352_reset_attach));
		/* Don't waste power and (maybe) pci bandwidth */
		mt352_sleep(i2c);
		return dvb_register_frontend(mt352_ioctl, i2c, (void *) card_type,
					     &mt352_info);
	}

	return -ENODEV;
}


static void mt352_detach (struct dvb_i2c_bus *i2c, void *data)
{
	mt352_sleep(i2c);
	dvb_unregister_frontend(mt352_ioctl, i2c);
}


static int __init init_mt352 (void)
{
	return dvb_register_i2c_device(NULL, mt352_attach, mt352_detach);
}


static void __exit exit_mt352 (void)
{
	dvb_unregister_i2c_device(mt352_attach);
}


module_init(init_mt352);
module_exit(exit_mt352);


MODULE_DESCRIPTION("DVB-T MT352 Zarlink");
MODULE_AUTHOR("Holger Waechtler, Daniel Mack");
MODULE_LICENSE("GPL");