// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *    Support for LGDT3302 and LGDT3303 - VSB/QAM
 *
 *    Copyright (C) 2005 Wilson Michaels <wilsonmichaels@earthlink.net>
 */

/*
 *                      NOTES ABOUT THIS DRIVER
 *
 * This Linux driver supports:
 *   DViCO FusionHDTV 3 Gold-Q
 *   DViCO FusionHDTV 3 Gold-T
 *   DViCO FusionHDTV 5 Gold
 *   DViCO FusionHDTV 5 Lite
 *   DViCO FusionHDTV 5 USB Gold
 *   Air2PC/AirStar 2 ATSC 3rd generation (HD5000)
 *   pcHDTV HD5500
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <asm/byteorder.h>

#include <media/dvb_frontend.h>
#include <media/dvb_math.h>
#include "lgdt330x_priv.h"
#include "lgdt330x.h"

/* Use Equalizer Mean Squared Error instead of Phaser Tracker MSE */
/* #define USE_EQMSE */

static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Turn on/off lgdt330x frontend debugging (default:off).");

#define dprintk(state, fmt, arg...) do {                                \
        if (debug)                                                      \
                dev_printk(KERN_DEBUG, &state->client->dev, fmt, ##arg);\
} while (0)

struct lgdt330x_state {
        struct i2c_client *client;

        /* Configuration settings */
        struct lgdt330x_config config;

        struct dvb_frontend frontend;

        /* Demodulator private data */
        enum fe_modulation current_modulation;
        u32 snr;        /* Result of last SNR calculation */
        u16 ucblocks;
        unsigned long last_stats_time;

        /* Tuner private data */
        u32 current_frequency;
};

static int i2c_write_demod_bytes(struct lgdt330x_state *state,
                                 const u8 *buf, /* data bytes to send */
                                 int len  /* number of bytes to send */)
{
        int i;
        int err;

        for (i = 0; i < len - 1; i += 2) {
                err = i2c_master_send(state->client, buf, 2);
                if (err != 2) {
                        dev_warn(&state->client->dev,
                                 "%s: error (addr %02x <- %02x, err = %i)\n",
                                __func__, buf[0], buf[1], err);
                        if (err < 0)
                                return err;
                        else
                                return -EREMOTEIO;
                }
                buf += 2;
        }
        return 0;
}

/*
 * This routine writes the register (reg) to the demod bus
 * then reads the data returned for (len) bytes.
 */
static int i2c_read_demod_bytes(struct lgdt330x_state *state,
                                enum I2C_REG reg, u8 *buf, int len)
{
        u8 wr[] = { reg };
        struct i2c_msg msg[] = {
                {
                        .addr = state->client->addr,
                        .flags = 0,
                        .buf = wr,
                        .len = 1
                }, {
                        .addr = state->client->addr,
                        .flags = I2C_M_RD,
                        .buf = buf,
                        .len = len
                },
        };
        int ret;

        ret = i2c_transfer(state->client->adapter, msg, 2);
        if (ret != 2) {
                dev_warn(&state->client->dev,
                         "%s: addr 0x%02x select 0x%02x error (ret == %i)\n",
                         __func__, state->client->addr, reg, ret);
                if (ret >= 0)
                        ret = -EIO;
        } else {
                ret = 0;
        }
        return ret;
}

/* Software reset */
static int lgdt3302_sw_reset(struct lgdt330x_state *state)
{
        u8 ret;
        u8 reset[] = {
                IRQ_MASK,
                /*
                 * bit 6 is active low software reset
                 * bits 5-0 are 1 to mask interrupts
                 */
                0x00
        };

        ret = i2c_write_demod_bytes(state,
                                    reset, sizeof(reset));
        if (ret == 0) {
                /* force reset high (inactive) and unmask interrupts */
                reset[1] = 0x7f;
                ret = i2c_write_demod_bytes(state,
                                            reset, sizeof(reset));
        }
        return ret;
}

static int lgdt3303_sw_reset(struct lgdt330x_state *state)
{
        u8 ret;
        u8 reset[] = {
                0x02,
                0x00 /* bit 0 is active low software reset */
        };

        ret = i2c_write_demod_bytes(state,
                                    reset, sizeof(reset));
        if (ret == 0) {
                /* force reset high (inactive) */
                reset[1] = 0x01;
                ret = i2c_write_demod_bytes(state,
                                            reset, sizeof(reset));
        }
        return ret;
}

static int lgdt330x_sw_reset(struct lgdt330x_state *state)
{
        switch (state->config.demod_chip) {
        case LGDT3302:
                return lgdt3302_sw_reset(state);
        case LGDT3303:
                return lgdt3303_sw_reset(state);
        default:
                return -ENODEV;
        }
}

static int lgdt330x_init(struct dvb_frontend *fe)
{
        struct lgdt330x_state *state = fe->demodulator_priv;
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        char  *chip_name;
        int    err;
        /*
         * Array of byte pairs <address, value>
         * to initialize each different chip
         */
        static const u8 lgdt3302_init_data[] = {
                /* Use 50MHz param values from spec sheet since xtal is 50 */
                /*
                 * Change the value of NCOCTFV[25:0] of carrier
                 * recovery center frequency register
                 */
                VSB_CARRIER_FREQ0, 0x00,
                VSB_CARRIER_FREQ1, 0x87,
                VSB_CARRIER_FREQ2, 0x8e,
                VSB_CARRIER_FREQ3, 0x01,
                /*
                 * Change the TPCLK pin polarity
                 * data is valid on falling clock
                 */
                DEMUX_CONTROL, 0xfb,
                /*
                 * Change the value of IFBW[11:0] of
                 * AGC IF/RF loop filter bandwidth register
                 */
                AGC_RF_BANDWIDTH0, 0x40,
                AGC_RF_BANDWIDTH1, 0x93,
                AGC_RF_BANDWIDTH2, 0x00,
                /*
                 * Change the value of bit 6, 'nINAGCBY' and
                 * 'NSSEL[1:0] of ACG function control register 2
                 */
                AGC_FUNC_CTRL2, 0xc6,
                /*
                 * Change the value of bit 6 'RFFIX'
                 * of AGC function control register 3
                 */
                AGC_FUNC_CTRL3, 0x40,
                /*
                 * Set the value of 'INLVTHD' register 0x2a/0x2c
                 * to 0x7fe
                 */
                AGC_DELAY0, 0x07,
                AGC_DELAY2, 0xfe,
                /*
                 * Change the value of IAGCBW[15:8]
                 * of inner AGC loop filter bandwidth
                 */
                AGC_LOOP_BANDWIDTH0, 0x08,
                AGC_LOOP_BANDWIDTH1, 0x9a
        };
        static const u8 lgdt3303_init_data[] = {
                0x4c, 0x14
        };
        static const u8 flip_1_lgdt3303_init_data[] = {
                0x4c, 0x14,
                0x87, 0xf3
        };
        static const u8 flip_2_lgdt3303_init_data[] = {
                0x4c, 0x14,
                0x87, 0xda
        };

        /*
         * Hardware reset is done using gpio[0] of cx23880x chip.
         * I'd like to do it here, but don't know how to find chip address.
         * cx88-cards.c arranges for the reset bit to be inactive (high).
         * Maybe there needs to be a callable function in cx88-core or
         * the caller of this function needs to do it.
         */

        switch (state->config.demod_chip) {
        case LGDT3302:
                chip_name = "LGDT3302";
                err = i2c_write_demod_bytes(state, lgdt3302_init_data,
                                            sizeof(lgdt3302_init_data));
                break;
        case LGDT3303:
                chip_name = "LGDT3303";
                switch (state->config.clock_polarity_flip) {
                case 2:
                        err = i2c_write_demod_bytes(state,
                                                    flip_2_lgdt3303_init_data,
                                                    sizeof(flip_2_lgdt3303_init_data));
                        break;
                case 1:
                        err = i2c_write_demod_bytes(state,
                                                    flip_1_lgdt3303_init_data,
                                                    sizeof(flip_1_lgdt3303_init_data));
                        break;
                case 0:
                default:
                        err = i2c_write_demod_bytes(state, lgdt3303_init_data,
                                                    sizeof(lgdt3303_init_data));
                }
                break;
        default:
                chip_name = "undefined";
                dev_warn(&state->client->dev,
                         "Only LGDT3302 and LGDT3303 are supported chips.\n");
                err = -ENODEV;
        }
        dprintk(state, "Initialized the %s chip\n", chip_name);
        if (err < 0)
                return err;

        p->cnr.len = 1;
        p->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        p->block_error.len = 1;
        p->block_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        p->block_count.len = 1;
        p->block_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        state->last_stats_time = 0;

        return lgdt330x_sw_reset(state);
}

static int lgdt330x_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
{
        struct lgdt330x_state *state = fe->demodulator_priv;

        *ucblocks = state->ucblocks;

        return 0;
}

static int lgdt330x_set_parameters(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        struct lgdt330x_state *state = fe->demodulator_priv;
        /*
         * Array of byte pairs <address, value>
         * to initialize 8VSB for lgdt3303 chip 50 MHz IF
         */
        static const u8 lgdt3303_8vsb_44_data[] = {
                0x04, 0x00,
                0x0d, 0x40,
                0x0e, 0x87,
                0x0f, 0x8e,
                0x10, 0x01,
                0x47, 0x8b
        };
        /*
         * Array of byte pairs <address, value>
         * to initialize QAM for lgdt3303 chip
         */
        static const u8 lgdt3303_qam_data[] = {
                0x04, 0x00,
                0x0d, 0x00,
                0x0e, 0x00,
                0x0f, 0x00,
                0x10, 0x00,
                0x51, 0x63,
                0x47, 0x66,
                0x48, 0x66,
                0x4d, 0x1a,
                0x49, 0x08,
                0x4a, 0x9b
        };
        u8 top_ctrl_cfg[]   = { TOP_CONTROL, 0x03 };

        int err = 0;
        /* Change only if we are actually changing the modulation */
        if (state->current_modulation != p->modulation) {
                switch (p->modulation) {
                case VSB_8:
                        dprintk(state, "VSB_8 MODE\n");

                        /* Select VSB mode */
                        top_ctrl_cfg[1] = 0x03;

                        /* Select ANT connector if supported by card */
                        if (state->config.pll_rf_set)
                                state->config.pll_rf_set(fe, 1);

                        if (state->config.demod_chip == LGDT3303) {
                                err = i2c_write_demod_bytes(state,
                                                            lgdt3303_8vsb_44_data,
                                                            sizeof(lgdt3303_8vsb_44_data));
                        }
                        break;

                case QAM_64:
                        dprintk(state, "QAM_64 MODE\n");

                        /* Select QAM_64 mode */
                        top_ctrl_cfg[1] = 0x00;

                        /* Select CABLE connector if supported by card */
                        if (state->config.pll_rf_set)
                                state->config.pll_rf_set(fe, 0);

                        if (state->config.demod_chip == LGDT3303) {
                                err = i2c_write_demod_bytes(state,
                                                            lgdt3303_qam_data,
                                                            sizeof(lgdt3303_qam_data));
                        }
                        break;

                case QAM_256:
                        dprintk(state, "QAM_256 MODE\n");

                        /* Select QAM_256 mode */
                        top_ctrl_cfg[1] = 0x01;

                        /* Select CABLE connector if supported by card */
                        if (state->config.pll_rf_set)
                                state->config.pll_rf_set(fe, 0);

                        if (state->config.demod_chip == LGDT3303) {
                                err = i2c_write_demod_bytes(state,
                                                            lgdt3303_qam_data,
                                                            sizeof(lgdt3303_qam_data));
                        }
                        break;
                default:
                        dev_warn(&state->client->dev,
                                 "%s: Modulation type(%d) UNSUPPORTED\n",
                                 __func__, p->modulation);
                        return -1;
                }
                if (err < 0)
                        dev_warn(&state->client->dev,
                                 "%s: error blasting bytes to lgdt3303 for modulation type(%d)\n",
                                 __func__, p->modulation);

                /*
                 * select serial or parallel MPEG hardware interface
                 * Serial:   0x04 for LGDT3302 or 0x40 for LGDT3303
                 * Parallel: 0x00
                 */
                top_ctrl_cfg[1] |= state->config.serial_mpeg;

                /* Select the requested mode */
                i2c_write_demod_bytes(state, top_ctrl_cfg,
                                      sizeof(top_ctrl_cfg));
                if (state->config.set_ts_params)
                        state->config.set_ts_params(fe, 0);
                state->current_modulation = p->modulation;
        }

        /* Tune to the specified frequency */
        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);
        }

        /* Keep track of the new frequency */
        /*
         * FIXME this is the wrong way to do this...
         * The tuner is shared with the video4linux analog API
         */
        state->current_frequency = p->frequency;

        lgdt330x_sw_reset(state);
        return 0;
}

static int lgdt330x_get_frontend(struct dvb_frontend *fe,
                                 struct dtv_frontend_properties *p)
{
        struct lgdt330x_state *state = fe->demodulator_priv;

        p->frequency = state->current_frequency;
        return 0;
}

/*
 * Calculate SNR estimation (scaled by 2^24)
 *
 * 8-VSB SNR equations from LGDT3302 and LGDT3303 datasheets, QAM
 * equations from LGDT3303 datasheet.  VSB is the same between the '02
 * and '03, so maybe QAM is too?  Perhaps someone with a newer datasheet
 * that has QAM information could verify?
 *
 * For 8-VSB: (two ways, take your pick)
 * LGDT3302:
 *   SNR_EQ = 10 * log10(25 * 24^2 / EQ_MSE)
 * LGDT3303:
 *   SNR_EQ = 10 * log10(25 * 32^2 / EQ_MSE)
 * LGDT3302 & LGDT3303:
 *   SNR_PT = 10 * log10(25 * 32^2 / PT_MSE)  (we use this one)
 * For 64-QAM:
 *   SNR    = 10 * log10( 688128   / MSEQAM)
 * For 256-QAM:
 *   SNR    = 10 * log10( 696320   / MSEQAM)
 *
 * We re-write the snr equation as:
 *   SNR * 2^24 = 10*(c - intlog10(MSE))
 * Where for 256-QAM, c = log10(696320) * 2^24, and so on.
 */
static u32 calculate_snr(u32 mse, u32 c)
{
        if (mse == 0) /* No signal */
                return 0;

        mse = intlog10(mse);
        if (mse > c) {
                /*
                 * Negative SNR, which is possible, but realisticly the
                 * demod will lose lock before the signal gets this bad.
                 * The API only allows for unsigned values, so just return 0
                 */
                return 0;
        }
        return 10 * (c - mse);
}

static int lgdt3302_read_snr(struct dvb_frontend *fe)
{
        struct lgdt330x_state *state = fe->demodulator_priv;
        u8 buf[5];      /* read data buffer */
        u32 noise;      /* noise value */
        u32 c;          /* per-modulation SNR calculation constant */

        switch (state->current_modulation) {
        case VSB_8:
                i2c_read_demod_bytes(state, LGDT3302_EQPH_ERR0, buf, 5);
#ifdef USE_EQMSE
                /* Use Equalizer Mean-Square Error Register */
                /* SNR for ranges from -15.61 to +41.58 */
                noise = ((buf[0] & 7) << 16) | (buf[1] << 8) | buf[2];
                c = 69765745; /* log10(25*24^2)*2^24 */
#else
                /* Use Phase Tracker Mean-Square Error Register */
                /* SNR for ranges from -13.11 to +44.08 */
                noise = ((buf[0] & 7 << 3) << 13) | (buf[3] << 8) | buf[4];
                c = 73957994; /* log10(25*32^2)*2^24 */
#endif
                break;
        case QAM_64:
        case QAM_256:
                i2c_read_demod_bytes(state, CARRIER_MSEQAM1, buf, 2);
                noise = ((buf[0] & 3) << 8) | buf[1];
                c = state->current_modulation == QAM_64 ? 97939837 : 98026066;
                /* log10(688128)*2^24 and log10(696320)*2^24 */
                break;
        default:
                dev_err(&state->client->dev,
                        "%s: Modulation set to unsupported value\n",
                        __func__);

                state->snr = 0;

                return -EREMOTEIO; /* return -EDRIVER_IS_GIBBERED; */
        }

        state->snr = calculate_snr(noise, c);

        dprintk(state, "noise = 0x%08x, snr = %d.%02d dB\n", noise,
                state->snr >> 24, (((state->snr >> 8) & 0xffff) * 100) >> 16);

        return 0;
}

static int lgdt3303_read_snr(struct dvb_frontend *fe)
{
        struct lgdt330x_state *state = fe->demodulator_priv;
        u8 buf[5];      /* read data buffer */
        u32 noise;      /* noise value */
        u32 c;          /* per-modulation SNR calculation constant */

        switch (state->current_modulation) {
        case VSB_8:
                i2c_read_demod_bytes(state, LGDT3303_EQPH_ERR0, buf, 5);
#ifdef USE_EQMSE
                /* Use Equalizer Mean-Square Error Register */
                /* SNR for ranges from -16.12 to +44.08 */
                noise = ((buf[0] & 0x78) << 13) | (buf[1] << 8) | buf[2];
                c = 73957994; /* log10(25*32^2)*2^24 */
#else
                /* Use Phase Tracker Mean-Square Error Register */
                /* SNR for ranges from -13.11 to +44.08 */
                noise = ((buf[0] & 7) << 16) | (buf[3] << 8) | buf[4];
                c = 73957994; /* log10(25*32^2)*2^24 */
#endif
                break;
        case QAM_64:
        case QAM_256:
                i2c_read_demod_bytes(state, CARRIER_MSEQAM1, buf, 2);
                noise = (buf[0] << 8) | buf[1];
                c = state->current_modulation == QAM_64 ? 97939837 : 98026066;
                /* log10(688128)*2^24 and log10(696320)*2^24 */
                break;
        default:
                dev_err(&state->client->dev,
                        "%s: Modulation set to unsupported value\n",
                        __func__);
                state->snr = 0;
                return -EREMOTEIO; /* return -EDRIVER_IS_GIBBERED; */
        }

        state->snr = calculate_snr(noise, c);

        dprintk(state, "noise = 0x%08x, snr = %d.%02d dB\n", noise,
                state->snr >> 24, (((state->snr >> 8) & 0xffff) * 100) >> 16);

        return 0;
}

static int lgdt330x_read_snr(struct dvb_frontend *fe, u16 *snr)
{
        struct lgdt330x_state *state = fe->demodulator_priv;

        *snr = (state->snr) >> 16; /* Convert from 8.24 fixed-point to 8.8 */

        return 0;
}

static int lgdt330x_read_signal_strength(struct dvb_frontend *fe, u16 *strength)
{
        /* Calculate Strength from SNR up to 35dB */
        /*
         * Even though the SNR can go higher than 35dB, there is some comfort
         * factor in having a range of strong signals that can show at 100%
         */
        struct lgdt330x_state *state = fe->demodulator_priv;
        u16 snr;
        int ret;

        ret = fe->ops.read_snr(fe, &snr);
        if (ret != 0)
                return ret;
        /* Rather than use the 8.8 value snr, use state->snr which is 8.24 */
        /* scale the range 0 - 35*2^24 into 0 - 65535 */
        if (state->snr >= 8960 * 0x10000)
                *strength = 0xffff;
        else
                *strength = state->snr / 8960;

        return 0;
}


static int lgdt3302_read_status(struct dvb_frontend *fe,
                                enum fe_status *status)
{
        struct lgdt330x_state *state = fe->demodulator_priv;
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        u8 buf[3];
        int err;

        *status = 0; /* Reset status result */

        /* AGC status register */
        i2c_read_demod_bytes(state, AGC_STATUS, buf, 1);
        dprintk(state, "AGC_STATUS = 0x%02x\n", buf[0]);
        if ((buf[0] & 0x0c) == 0x8) {
                /*
                 * Test signal does not exist flag
                 * as well as the AGC lock flag.
                 */
                *status |= FE_HAS_SIGNAL;
        }

        /*
         * You must set the Mask bits to 1 in the IRQ_MASK in order
         * to see that status bit in the IRQ_STATUS register.
         * This is done in SwReset();
         */

        /* signal status */
        i2c_read_demod_bytes(state, TOP_CONTROL, buf, sizeof(buf));
        dprintk(state,
                "TOP_CONTROL = 0x%02x, IRO_MASK = 0x%02x, IRQ_STATUS = 0x%02x\n",
                buf[0], buf[1], buf[2]);

        /* sync status */
        if ((buf[2] & 0x03) == 0x01)
                *status |= FE_HAS_SYNC;

        /* FEC error status */
        if ((buf[2] & 0x0c) == 0x08)
                *status |= FE_HAS_LOCK | FE_HAS_VITERBI;

        /* Carrier Recovery Lock Status Register */
        i2c_read_demod_bytes(state, CARRIER_LOCK, buf, 1);
        dprintk(state, "CARRIER_LOCK = 0x%02x\n", buf[0]);
        switch (state->current_modulation) {
        case QAM_256:
        case QAM_64:
                /* Need to understand why there are 3 lock levels here */
                if ((buf[0] & 0x07) == 0x07)
                        *status |= FE_HAS_CARRIER;
                break;
        case VSB_8:
                if ((buf[0] & 0x80) == 0x80)
                        *status |= FE_HAS_CARRIER;
                break;
        default:
                dev_warn(&state->client->dev,
                         "%s: Modulation set to unsupported value\n",
                         __func__);
        }

        if (!(*status & FE_HAS_LOCK)) {
                p->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
                p->block_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
                p->block_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
                return 0;
        }

        if (state->last_stats_time &&
            time_is_after_jiffies(state->last_stats_time))
                return 0;

        state->last_stats_time = jiffies + msecs_to_jiffies(1000);

        err = lgdt3302_read_snr(fe);
        if (!err) {
                p->cnr.stat[0].scale = FE_SCALE_DECIBEL;
                p->cnr.stat[0].svalue = (((u64)state->snr) * 1000) >> 24;
        } else {
                p->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        }

        err = i2c_read_demod_bytes(state, LGDT3302_PACKET_ERR_COUNTER1,
                                           buf, sizeof(buf));
        if (!err) {
                state->ucblocks = (buf[0] << 8) | buf[1];

                dprintk(state, "UCB = 0x%02x\n", state->ucblocks);

                p->block_error.stat[0].uvalue += state->ucblocks;
                /* FIXME: what's the basis for block count */
                p->block_count.stat[0].uvalue += 10000;

                p->block_error.stat[0].scale = FE_SCALE_COUNTER;
                p->block_count.stat[0].scale = FE_SCALE_COUNTER;
        } else {
                p->block_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
                p->block_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        }

        return 0;
}

static int lgdt3303_read_status(struct dvb_frontend *fe,
                                enum fe_status *status)
{
        struct lgdt330x_state *state = fe->demodulator_priv;
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        u8 buf[3];
        int err;

        *status = 0; /* Reset status result */

        /* lgdt3303 AGC status register */
        err = i2c_read_demod_bytes(state, 0x58, buf, 1);
        if (err < 0)
                return err;

        dprintk(state, "AGC_STATUS = 0x%02x\n", buf[0]);
        if ((buf[0] & 0x21) == 0x01) {
                /*
                 * Test input signal does not exist flag
                 * as well as the AGC lock flag.
                 */
                *status |= FE_HAS_SIGNAL;
        }

        /* Carrier Recovery Lock Status Register */
        i2c_read_demod_bytes(state, CARRIER_LOCK, buf, 1);
        dprintk(state, "CARRIER_LOCK = 0x%02x\n", buf[0]);
        switch (state->current_modulation) {
        case QAM_256:
        case QAM_64:
                /* Need to understand why there are 3 lock levels here */
                if ((buf[0] & 0x07) == 0x07)
                        *status |= FE_HAS_CARRIER;
                else
                        break;
                i2c_read_demod_bytes(state, 0x8a, buf, 1);
                dprintk(state, "QAM LOCK = 0x%02x\n", buf[0]);

                if ((buf[0] & 0x04) == 0x04)
                        *status |= FE_HAS_SYNC;
                if ((buf[0] & 0x01) == 0x01)
                        *status |= FE_HAS_LOCK;
                if ((buf[0] & 0x08) == 0x08)
                        *status |= FE_HAS_VITERBI;
                break;
        case VSB_8:
                if ((buf[0] & 0x80) == 0x80)
                        *status |= FE_HAS_CARRIER;
                else
                        break;
                i2c_read_demod_bytes(state, 0x38, buf, 1);
                dprintk(state, "8-VSB LOCK = 0x%02x\n", buf[0]);

                if ((buf[0] & 0x02) == 0x00)
                        *status |= FE_HAS_SYNC;
                if ((buf[0] & 0x01) == 0x01)
                        *status |= FE_HAS_VITERBI | FE_HAS_LOCK;
                break;
        default:
                dev_warn(&state->client->dev,
                         "%s: Modulation set to unsupported value\n",
                         __func__);
        }

        if (!(*status & FE_HAS_LOCK)) {
                p->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
                p->block_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
                p->block_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
                return 0;
        }

        if (state->last_stats_time &&
            time_is_after_jiffies(state->last_stats_time))
                return 0;

        state->last_stats_time = jiffies + msecs_to_jiffies(1000);

        err = lgdt3303_read_snr(fe);
        if (!err) {
                p->cnr.stat[0].scale = FE_SCALE_DECIBEL;
                p->cnr.stat[0].svalue = (((u64)state->snr) * 1000) >> 24;
        } else {
                p->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        }

        err = i2c_read_demod_bytes(state, LGDT3303_PACKET_ERR_COUNTER1,
                                           buf, sizeof(buf));
        if (!err) {
                state->ucblocks = (buf[0] << 8) | buf[1];

                dprintk(state, "UCB = 0x%02x\n", state->ucblocks);

                p->block_error.stat[0].uvalue += state->ucblocks;
                /* FIXME: what's the basis for block count */
                p->block_count.stat[0].uvalue += 10000;

                p->block_error.stat[0].scale = FE_SCALE_COUNTER;
                p->block_count.stat[0].scale = FE_SCALE_COUNTER;
        } else {
                p->block_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
                p->block_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        }

        return 0;
}

static int
lgdt330x_get_tune_settings(struct dvb_frontend *fe,
                           struct dvb_frontend_tune_settings *fe_tune_settings)
{
        /* I have no idea about this - it may not be needed */
        fe_tune_settings->min_delay_ms = 500;
        fe_tune_settings->step_size = 0;
        fe_tune_settings->max_drift = 0;
        return 0;
}

static void lgdt330x_release(struct dvb_frontend *fe)
{
        struct lgdt330x_state *state = fe->demodulator_priv;
        struct i2c_client *client = state->client;

        dev_dbg(&client->dev, "\n");

        i2c_unregister_device(client);
}

static struct dvb_frontend *lgdt330x_get_dvb_frontend(struct i2c_client *client)
{
        struct lgdt330x_state *state = i2c_get_clientdata(client);

        dev_dbg(&client->dev, "\n");

        return &state->frontend;
}

static const struct dvb_frontend_ops lgdt3302_ops;
static const struct dvb_frontend_ops lgdt3303_ops;

static int lgdt330x_probe(struct i2c_client *client,
                          const struct i2c_device_id *id)
{
        struct lgdt330x_state *state = NULL;
        u8 buf[1];

        /* Allocate memory for the internal state */
        state = kzalloc(sizeof(*state), GFP_KERNEL);
        if (!state)
                goto error;

        /* Setup the state */
        memcpy(&state->config, client->dev.platform_data,
               sizeof(state->config));
        i2c_set_clientdata(client, state);
        state->client = client;

        /* Create dvb_frontend */
        switch (state->config.demod_chip) {
        case LGDT3302:
                memcpy(&state->frontend.ops, &lgdt3302_ops,
                       sizeof(struct dvb_frontend_ops));
                break;
        case LGDT3303:
                memcpy(&state->frontend.ops, &lgdt3303_ops,
                       sizeof(struct dvb_frontend_ops));
                break;
        default:
                goto error;
        }
        state->frontend.demodulator_priv = state;

        /* Setup get frontend callback */
        state->config.get_dvb_frontend = lgdt330x_get_dvb_frontend;

        /* Verify communication with demod chip */
        if (i2c_read_demod_bytes(state, 2, buf, 1))
                goto error;

        state->current_frequency = -1;
        state->current_modulation = -1;

        dev_info(&state->client->dev,
                "Demod loaded for LGDT330%s chip\n",
                state->config.demod_chip == LGDT3302 ? "2" : "3");

        return 0;

error:
        kfree(state);
        if (debug)
                dev_printk(KERN_DEBUG, &client->dev, "Error loading lgdt330x driver\n");
        return -ENODEV;
}
struct dvb_frontend *lgdt330x_attach(const struct lgdt330x_config *_config,
                                     u8 demod_address,
                                     struct i2c_adapter *i2c)
{
        struct i2c_client *client;
        struct i2c_board_info board_info = {};
        struct lgdt330x_config config = *_config;

        strscpy(board_info.type, "lgdt330x", sizeof(board_info.type));
        board_info.addr = demod_address;
        board_info.platform_data = &config;
        client = i2c_new_client_device(i2c, &board_info);
        if (!i2c_client_has_driver(client))
                return NULL;

        return lgdt330x_get_dvb_frontend(client);
}
EXPORT_SYMBOL(lgdt330x_attach);

static const struct dvb_frontend_ops lgdt3302_ops = {
        .delsys = { SYS_ATSC, SYS_DVBC_ANNEX_B },
        .info = {
                .name = "LG Electronics LGDT3302 VSB/QAM Frontend",
                .frequency_min_hz =  54 * MHz,
                .frequency_max_hz = 858 * MHz,
                .frequency_stepsize_hz = 62500,
                .symbol_rate_min    = 5056941,  /* QAM 64 */
                .symbol_rate_max    = 10762000, /* VSB 8  */
                .caps = FE_CAN_QAM_64 | FE_CAN_QAM_256 | FE_CAN_8VSB
        },
        .init                 = lgdt330x_init,
        .set_frontend         = lgdt330x_set_parameters,
        .get_frontend         = lgdt330x_get_frontend,
        .get_tune_settings    = lgdt330x_get_tune_settings,
        .read_status          = lgdt3302_read_status,
        .read_signal_strength = lgdt330x_read_signal_strength,
        .read_snr             = lgdt330x_read_snr,
        .read_ucblocks        = lgdt330x_read_ucblocks,
        .release              = lgdt330x_release,
};

static const struct dvb_frontend_ops lgdt3303_ops = {
        .delsys = { SYS_ATSC, SYS_DVBC_ANNEX_B },
        .info = {
                .name = "LG Electronics LGDT3303 VSB/QAM Frontend",
                .frequency_min_hz =  54 * MHz,
                .frequency_max_hz = 858 * MHz,
                .frequency_stepsize_hz = 62500,
                .symbol_rate_min    = 5056941,  /* QAM 64 */
                .symbol_rate_max    = 10762000, /* VSB 8  */
                .caps = FE_CAN_QAM_64 | FE_CAN_QAM_256 | FE_CAN_8VSB
        },
        .init                 = lgdt330x_init,
        .set_frontend         = lgdt330x_set_parameters,
        .get_frontend         = lgdt330x_get_frontend,
        .get_tune_settings    = lgdt330x_get_tune_settings,
        .read_status          = lgdt3303_read_status,
        .read_signal_strength = lgdt330x_read_signal_strength,
        .read_snr             = lgdt330x_read_snr,
        .read_ucblocks        = lgdt330x_read_ucblocks,
        .release              = lgdt330x_release,
};

static int lgdt330x_remove(struct i2c_client *client)
{
        struct lgdt330x_state *state = i2c_get_clientdata(client);

        dev_dbg(&client->dev, "\n");

        kfree(state);

        return 0;
}

static const struct i2c_device_id lgdt330x_id_table[] = {
        {"lgdt330x", 0},
        {}
};
MODULE_DEVICE_TABLE(i2c, lgdt330x_id_table);

static struct i2c_driver lgdt330x_driver = {
        .driver = {
                .name   = "lgdt330x",
                .suppress_bind_attrs = true,
        },
        .probe          = lgdt330x_probe,
        .remove         = lgdt330x_remove,

        .id_table       = lgdt330x_id_table,
};

module_i2c_driver(lgdt330x_driver);


MODULE_DESCRIPTION("LGDT330X (ATSC 8VSB & ITU-T J.83 AnnexB 64/256 QAM) Demodulator Driver");
MODULE_AUTHOR("Wilson Michaels");
MODULE_LICENSE("GPL");