/*
  	NxtWave Communications - NXT6000 demodulator driver
  
      Copyright (C) 2002-2003 Florian Schirmer <jolt@tuxbox.org>
      Copyright (C) 2003 Paul Andreassen <paul@andreassen.com.au>
  
      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/slab.h>
  
  #include "dvb_frontend.h"
  #include "nxt6000_priv.h"
  #include "nxt6000.h"
  
  
  
  struct nxt6000_state {
  	struct i2c_adapter* i2c;
  	/* configuration settings */
  	const struct nxt6000_config* config;
  	struct dvb_frontend frontend;
  };
  
  static int debug;
  #define dprintk if (debug) printk
  
  static int nxt6000_writereg(struct nxt6000_state* state, u8 reg, u8 data)
  {
  	u8 buf[] = { reg, data };
  	struct i2c_msg msg = {.addr = state->config->demod_address,.flags = 0,.buf = buf,.len = 2 };
  	int ret;
  
  	if ((ret = i2c_transfer(state->i2c, &msg, 1)) != 1)
  		dprintk("nxt6000: nxt6000_write error (reg: 0x%02X, data: 0x%02X, ret: %d)
  ", reg, data, ret);
  
  	return (ret != 1) ? -EIO : 0;
  }
  
  static u8 nxt6000_readreg(struct nxt6000_state* state, u8 reg)
  {
  	int ret;
  	u8 b0[] = { reg };
  	u8 b1[] = { 0 };
  	struct i2c_msg msgs[] = {
  		{.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, msgs, 2);
  
  	if (ret != 2)
  		dprintk("nxt6000: nxt6000_read error (reg: 0x%02X, ret: %d)
  ", reg, ret);
  
  	return b1[0];
  }
  
  static void nxt6000_reset(struct nxt6000_state* state)
  {
  	u8 val;
  
  	val = nxt6000_readreg(state, OFDM_COR_CTL);
  
  	nxt6000_writereg(state, OFDM_COR_CTL, val & ~COREACT);
  	nxt6000_writereg(state, OFDM_COR_CTL, val | COREACT);
  }
  
  static int nxt6000_set_bandwidth(struct nxt6000_state *state, u32 bandwidth)
  {
  	u16 nominal_rate;
  	int result;
  
  	switch (bandwidth) {
  	case 6000000:
  		nominal_rate = 0x55B7;
  		break;
  
  	case 7000000:
  		nominal_rate = 0x6400;
  		break;
  
  	case 8000000:
  		nominal_rate = 0x7249;
  		break;
  
  	default:
  		return -EINVAL;
  	}
  
  	if ((result = nxt6000_writereg(state, OFDM_TRL_NOMINALRATE_1, nominal_rate & 0xFF)) < 0)
  		return result;
  
  	return nxt6000_writereg(state, OFDM_TRL_NOMINALRATE_2, (nominal_rate >> 8) & 0xFF);
  }
  
  static int nxt6000_set_guard_interval(struct nxt6000_state* state, fe_guard_interval_t guard_interval)
  {
  	switch (guard_interval) {
  
  	case GUARD_INTERVAL_1_32:
  		return nxt6000_writereg(state, OFDM_COR_MODEGUARD, 0x00 | (nxt6000_readreg(state, OFDM_COR_MODEGUARD) & ~0x03));
  
  	case GUARD_INTERVAL_1_16:
  		return nxt6000_writereg(state, OFDM_COR_MODEGUARD, 0x01 | (nxt6000_readreg(state, OFDM_COR_MODEGUARD) & ~0x03));
  
  	case GUARD_INTERVAL_AUTO:
  	case GUARD_INTERVAL_1_8:
  		return nxt6000_writereg(state, OFDM_COR_MODEGUARD, 0x02 | (nxt6000_readreg(state, OFDM_COR_MODEGUARD) & ~0x03));
  
  	case GUARD_INTERVAL_1_4:
  		return nxt6000_writereg(state, OFDM_COR_MODEGUARD, 0x03 | (nxt6000_readreg(state, OFDM_COR_MODEGUARD) & ~0x03));
  
  	default:
  		return -EINVAL;
  	}
  }
  
  static int nxt6000_set_inversion(struct nxt6000_state* state, fe_spectral_inversion_t inversion)
  {
  	switch (inversion) {
  
  	case INVERSION_OFF:
  		return nxt6000_writereg(state, OFDM_ITB_CTL, 0x00);
  
  	case INVERSION_ON:
  		return nxt6000_writereg(state, OFDM_ITB_CTL, ITBINV);
  
  	default:
  		return -EINVAL;
  
  	}
  }
  
  static int nxt6000_set_transmission_mode(struct nxt6000_state* state, fe_transmit_mode_t transmission_mode)
  {
  	int result;
  
  	switch (transmission_mode) {
  
  	case TRANSMISSION_MODE_2K:
  		if ((result = nxt6000_writereg(state, EN_DMD_RACQ, 0x00 | (nxt6000_readreg(state, EN_DMD_RACQ) & ~0x03))) < 0)
  			return result;
  
  		return nxt6000_writereg(state, OFDM_COR_MODEGUARD, (0x00 << 2) | (nxt6000_readreg(state, OFDM_COR_MODEGUARD) & ~0x04));
  
  	case TRANSMISSION_MODE_8K:
  	case TRANSMISSION_MODE_AUTO:
  		if ((result = nxt6000_writereg(state, EN_DMD_RACQ, 0x02 | (nxt6000_readreg(state, EN_DMD_RACQ) & ~0x03))) < 0)
  			return result;
  
  		return nxt6000_writereg(state, OFDM_COR_MODEGUARD, (0x01 << 2) | (nxt6000_readreg(state, OFDM_COR_MODEGUARD) & ~0x04));
  
  	default:
  		return -EINVAL;
  
  	}
  }
  
  static void nxt6000_setup(struct dvb_frontend* fe)
  {
  	struct nxt6000_state* state = fe->demodulator_priv;
  
  	nxt6000_writereg(state, RS_COR_SYNC_PARAM, SYNC_PARAM);
  	nxt6000_writereg(state, BER_CTRL, /*(1 << 2) | */ (0x01 << 1) | 0x01);
  	nxt6000_writereg(state, VIT_BERTIME_2, 0x00);  // BER Timer = 0x000200 * 256 = 131072 bits
  	nxt6000_writereg(state, VIT_BERTIME_1, 0x02);  //
  	nxt6000_writereg(state, VIT_BERTIME_0, 0x00);  //
  	nxt6000_writereg(state, VIT_COR_INTEN, 0x98); // Enable BER interrupts
  	nxt6000_writereg(state, VIT_COR_CTL, 0x82);   // Enable BER measurement
  	nxt6000_writereg(state, VIT_COR_CTL, VIT_COR_RESYNC | 0x02 );
  	nxt6000_writereg(state, OFDM_COR_CTL, (0x01 << 5) | (nxt6000_readreg(state, OFDM_COR_CTL) & 0x0F));
  	nxt6000_writereg(state, OFDM_COR_MODEGUARD, FORCEMODE8K | 0x02);
  	nxt6000_writereg(state, OFDM_AGC_CTL, AGCLAST | INITIAL_AGC_BW);
  	nxt6000_writereg(state, OFDM_ITB_FREQ_1, 0x06);
  	nxt6000_writereg(state, OFDM_ITB_FREQ_2, 0x31);
  	nxt6000_writereg(state, OFDM_CAS_CTL, (0x01 << 7) | (0x02 << 3) | 0x04);
  	nxt6000_writereg(state, CAS_FREQ, 0xBB);	/* CHECKME */
  	nxt6000_writereg(state, OFDM_SYR_CTL, 1 << 2);
  	nxt6000_writereg(state, OFDM_PPM_CTL_1, PPM256);
  	nxt6000_writereg(state, OFDM_TRL_NOMINALRATE_1, 0x49);
  	nxt6000_writereg(state, OFDM_TRL_NOMINALRATE_2, 0x72);
  	nxt6000_writereg(state, ANALOG_CONTROL_0, 1 << 5);
  	nxt6000_writereg(state, EN_DMD_RACQ, (1 << 7) | (3 << 4) | 2);
  	nxt6000_writereg(state, DIAG_CONFIG, TB_SET);
  
  	if (state->config->clock_inversion)
  		nxt6000_writereg(state, SUB_DIAG_MODE_SEL, CLKINVERSION);
  	else
  		nxt6000_writereg(state, SUB_DIAG_MODE_SEL, 0);
  
  	nxt6000_writereg(state, TS_FORMAT, 0);
  }
  
  static void nxt6000_dump_status(struct nxt6000_state *state)
  {
  	u8 val;
  
  /*
  	printk("RS_COR_STAT: 0x%02X
  ", nxt6000_readreg(fe, RS_COR_STAT));
  	printk("VIT_SYNC_STATUS: 0x%02X
  ", nxt6000_readreg(fe, VIT_SYNC_STATUS));
  	printk("OFDM_COR_STAT: 0x%02X
  ", nxt6000_readreg(fe, OFDM_COR_STAT));
  	printk("OFDM_SYR_STAT: 0x%02X
  ", nxt6000_readreg(fe, OFDM_SYR_STAT));
  	printk("OFDM_TPS_RCVD_1: 0x%02X
  ", nxt6000_readreg(fe, OFDM_TPS_RCVD_1));
  	printk("OFDM_TPS_RCVD_2: 0x%02X
  ", nxt6000_readreg(fe, OFDM_TPS_RCVD_2));
  	printk("OFDM_TPS_RCVD_3: 0x%02X
  ", nxt6000_readreg(fe, OFDM_TPS_RCVD_3));
  	printk("OFDM_TPS_RCVD_4: 0x%02X
  ", nxt6000_readreg(fe, OFDM_TPS_RCVD_4));
  	printk("OFDM_TPS_RESERVED_1: 0x%02X
  ", nxt6000_readreg(fe, OFDM_TPS_RESERVED_1));
  	printk("OFDM_TPS_RESERVED_2: 0x%02X
  ", nxt6000_readreg(fe, OFDM_TPS_RESERVED_2));
  */
  	printk("NXT6000 status:");
  
  	val = nxt6000_readreg(state, RS_COR_STAT);
  
  	printk(" DATA DESCR LOCK: %d,", val & 0x01);
  	printk(" DATA SYNC LOCK: %d,", (val >> 1) & 0x01);
  
  	val = nxt6000_readreg(state, VIT_SYNC_STATUS);
  
  	printk(" VITERBI LOCK: %d,", (val >> 7) & 0x01);
  
  	switch ((val >> 4) & 0x07) {
  
  	case 0x00:
  		printk(" VITERBI CODERATE: 1/2,");
  		break;
  
  	case 0x01:
  		printk(" VITERBI CODERATE: 2/3,");
  		break;
  
  	case 0x02:
  		printk(" VITERBI CODERATE: 3/4,");
  		break;
  
  	case 0x03:
  		printk(" VITERBI CODERATE: 5/6,");
  		break;
  
  	case 0x04:
  		printk(" VITERBI CODERATE: 7/8,");
  		break;
  
  	default:
  		printk(" VITERBI CODERATE: Reserved,");
  
  	}
  
  	val = nxt6000_readreg(state, OFDM_COR_STAT);
  
  	printk(" CHCTrack: %d,", (val >> 7) & 0x01);
  	printk(" TPSLock: %d,", (val >> 6) & 0x01);
  	printk(" SYRLock: %d,", (val >> 5) & 0x01);
  	printk(" AGCLock: %d,", (val >> 4) & 0x01);
  
  	switch (val & 0x0F) {
  
  	case 0x00:
  		printk(" CoreState: IDLE,");
  		break;
  
  	case 0x02:
  		printk(" CoreState: WAIT_AGC,");
  		break;
  
  	case 0x03:
  		printk(" CoreState: WAIT_SYR,");
  		break;
  
  	case 0x04:
  		printk(" CoreState: WAIT_PPM,");
  		break;
  
  	case 0x01:
  		printk(" CoreState: WAIT_TRL,");
  		break;
  
  	case 0x05:
  		printk(" CoreState: WAIT_TPS,");
  		break;
  
  	case 0x06:
  		printk(" CoreState: MONITOR_TPS,");
  		break;
  
  	default:
  		printk(" CoreState: Reserved,");
  
  	}
  
  	val = nxt6000_readreg(state, OFDM_SYR_STAT);
  
  	printk(" SYRLock: %d,", (val >> 4) & 0x01);
  	printk(" SYRMode: %s,", (val >> 2) & 0x01 ? "8K" : "2K");
  
  	switch ((val >> 4) & 0x03) {
  
  	case 0x00:
  		printk(" SYRGuard: 1/32,");
  		break;
  
  	case 0x01:
  		printk(" SYRGuard: 1/16,");
  		break;
  
  	case 0x02:
  		printk(" SYRGuard: 1/8,");
  		break;
  
  	case 0x03:
  		printk(" SYRGuard: 1/4,");
  		break;
  	}
  
  	val = nxt6000_readreg(state, OFDM_TPS_RCVD_3);
  
  	switch ((val >> 4) & 0x07) {
  
  	case 0x00:
  		printk(" TPSLP: 1/2,");
  		break;
  
  	case 0x01:
  		printk(" TPSLP: 2/3,");
  		break;
  
  	case 0x02:
  		printk(" TPSLP: 3/4,");
  		break;
  
  	case 0x03:
  		printk(" TPSLP: 5/6,");
  		break;
  
  	case 0x04:
  		printk(" TPSLP: 7/8,");
  		break;
  
  	default:
  		printk(" TPSLP: Reserved,");
  
  	}
  
  	switch (val & 0x07) {
  
  	case 0x00:
  		printk(" TPSHP: 1/2,");
  		break;
  
  	case 0x01:
  		printk(" TPSHP: 2/3,");
  		break;
  
  	case 0x02:
  		printk(" TPSHP: 3/4,");
  		break;
  
  	case 0x03:
  		printk(" TPSHP: 5/6,");
  		break;
  
  	case 0x04:
  		printk(" TPSHP: 7/8,");
  		break;
  
  	default:
  		printk(" TPSHP: Reserved,");
  
  	}
  
  	val = nxt6000_readreg(state, OFDM_TPS_RCVD_4);
  
  	printk(" TPSMode: %s,", val & 0x01 ? "8K" : "2K");
  
  	switch ((val >> 4) & 0x03) {
  
  	case 0x00:
  		printk(" TPSGuard: 1/32,");
  		break;
  
  	case 0x01:
  		printk(" TPSGuard: 1/16,");
  		break;
  
  	case 0x02:
  		printk(" TPSGuard: 1/8,");
  		break;
  
  	case 0x03:
  		printk(" TPSGuard: 1/4,");
  		break;
  
  	}
  
  	/* Strange magic required to gain access to RF_AGC_STATUS */
  	nxt6000_readreg(state, RF_AGC_VAL_1);
  	val = nxt6000_readreg(state, RF_AGC_STATUS);
  	val = nxt6000_readreg(state, RF_AGC_STATUS);
  
  	printk(" RF AGC LOCK: %d,", (val >> 4) & 0x01);
  	printk("
  ");
  }
  
  static int nxt6000_read_status(struct dvb_frontend* fe, fe_status_t* status)
  {
  	u8 core_status;
  	struct nxt6000_state* state = fe->demodulator_priv;
  
  	*status = 0;
  
  	core_status = nxt6000_readreg(state, OFDM_COR_STAT);
  
  	if (core_status & AGCLOCKED)
  		*status |= FE_HAS_SIGNAL;
  
  	if (nxt6000_readreg(state, OFDM_SYR_STAT) & GI14_SYR_LOCK)
  		*status |= FE_HAS_CARRIER;
  
  	if (nxt6000_readreg(state, VIT_SYNC_STATUS) & VITINSYNC)
  		*status |= FE_HAS_VITERBI;
  
  	if (nxt6000_readreg(state, RS_COR_STAT) & RSCORESTATUS)
  		*status |= FE_HAS_SYNC;
  
  	if ((core_status & TPSLOCKED) && (*status == (FE_HAS_SIGNAL | FE_HAS_CARRIER | FE_HAS_VITERBI | FE_HAS_SYNC)))
  		*status |= FE_HAS_LOCK;
  
  	if (debug)
  		nxt6000_dump_status(state);
  
  	return 0;
  }
  
  static int nxt6000_init(struct dvb_frontend* fe)
  {
  	struct nxt6000_state* state = fe->demodulator_priv;
  
  	nxt6000_reset(state);
  	nxt6000_setup(fe);
  
  	return 0;
  }
  
  static int nxt6000_set_frontend(struct dvb_frontend *fe)
  {
  	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
  	struct nxt6000_state* state = fe->demodulator_priv;
  	int result;
  
  	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);
  	}
  
  	result = nxt6000_set_bandwidth(state, p->bandwidth_hz);
  	if (result < 0)
  		return result;
  
  	result = nxt6000_set_guard_interval(state, p->guard_interval);
  	if (result < 0)
  		return result;
  
  	result = nxt6000_set_transmission_mode(state, p->transmission_mode);
  	if (result < 0)
  		return result;
  
  	result = nxt6000_set_inversion(state, p->inversion);
  	if (result < 0)
  		return result;
  
  	msleep(500);
  	return 0;
  }
  
  static void nxt6000_release(struct dvb_frontend* fe)
  {
  	struct nxt6000_state* state = fe->demodulator_priv;
  	kfree(state);
  }
  
  static int nxt6000_read_snr(struct dvb_frontend* fe, u16* snr)
  {
  	struct nxt6000_state* state = fe->demodulator_priv;
  
  	*snr = nxt6000_readreg( state, OFDM_CHC_SNR) / 8;
  
  	return 0;
  }
  
  static int nxt6000_read_ber(struct dvb_frontend* fe, u32* ber)
  {
  	struct nxt6000_state* state = fe->demodulator_priv;
  
  	nxt6000_writereg( state, VIT_COR_INTSTAT, 0x18 );
  
  	*ber = (nxt6000_readreg( state, VIT_BER_1 ) << 8 ) |
  		nxt6000_readreg( state, VIT_BER_0 );
  
  	nxt6000_writereg( state, VIT_COR_INTSTAT, 0x18); // Clear BER Done interrupts
  
  	return 0;
  }
  
  static int nxt6000_read_signal_strength(struct dvb_frontend* fe, u16* signal_strength)
  {
  	struct nxt6000_state* state = fe->demodulator_priv;
  
  	*signal_strength = (short) (511 -
  		(nxt6000_readreg(state, AGC_GAIN_1) +
  		((nxt6000_readreg(state, AGC_GAIN_2) & 0x03) << 8)));
  
  	return 0;
  }
  
  static int nxt6000_fe_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings *tune)
  {
  	tune->min_delay_ms = 500;
  	return 0;
  }
  
  static int nxt6000_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
  {
  	struct nxt6000_state* state = fe->demodulator_priv;
  
  	if (enable) {
  		return nxt6000_writereg(state, ENABLE_TUNER_IIC, 0x01);
  	} else {
  		return nxt6000_writereg(state, ENABLE_TUNER_IIC, 0x00);
  	}
  }
  
  static struct dvb_frontend_ops nxt6000_ops;
  
  struct dvb_frontend* nxt6000_attach(const struct nxt6000_config* config,
  				    struct i2c_adapter* i2c)
  {
  	struct nxt6000_state* state = NULL;
  
  	/* allocate memory for the internal state */
  	state = kzalloc(sizeof(struct nxt6000_state), GFP_KERNEL);
  	if (state == NULL) goto error;
  
  	/* setup the state */
  	state->config = config;
  	state->i2c = i2c;
  
  	/* check if the demod is there */
  	if (nxt6000_readreg(state, OFDM_MSC_REV) != NXT6000ASICDEVICE) goto error;
  
  	/* create dvb_frontend */
  	memcpy(&state->frontend.ops, &nxt6000_ops, sizeof(struct dvb_frontend_ops));
  	state->frontend.demodulator_priv = state;
  	return &state->frontend;
  
  error:
  	kfree(state);
  	return NULL;
  }
  
  static struct dvb_frontend_ops nxt6000_ops = {
  	.delsys = { SYS_DVBT },
  	.info = {
  		.name = "NxtWave NXT6000 DVB-T",
  		.frequency_min = 0,
  		.frequency_max = 863250000,
  		.frequency_stepsize = 62500,
  		/*.frequency_tolerance = *//* FIXME: 12% of SR */
  		.symbol_rate_min = 0,	/* FIXME */
  		.symbol_rate_max = 9360000,	/* FIXME */
  		.symbol_rate_tolerance = 4000,
  		.caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
  			FE_CAN_FEC_4_5 | FE_CAN_FEC_5_6 | FE_CAN_FEC_6_7 |
  			FE_CAN_FEC_7_8 | FE_CAN_FEC_8_9 | FE_CAN_FEC_AUTO |
  			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,
  	},
  
  	.release = nxt6000_release,
  
  	.init = nxt6000_init,
  	.i2c_gate_ctrl = nxt6000_i2c_gate_ctrl,
  
  	.get_tune_settings = nxt6000_fe_get_tune_settings,
  
  	.set_frontend = nxt6000_set_frontend,
  
  	.read_status = nxt6000_read_status,
  	.read_ber = nxt6000_read_ber,
  	.read_signal_strength = nxt6000_read_signal_strength,
  	.read_snr = nxt6000_read_snr,
  };
  
  module_param(debug, int, 0644);
  MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
  
  MODULE_DESCRIPTION("NxtWave NXT6000 DVB-T demodulator driver");
  MODULE_AUTHOR("Florian Schirmer");
  MODULE_LICENSE("GPL");
  
  EXPORT_SYMBOL(nxt6000_attach);