/*
 *    Support for LGDT3302 and LGDT3303 - VSB/QAM
 *
 *    Copyright (C) 2005 Wilson Michaels <wilsonmichaels@earthlink.net>
 *
 *    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.
 *
 */

/*
 *                      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 "dvb_frontend.h"
#include "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(args...) \
do { \
if (debug) printk(KERN_DEBUG "lgdt330x: " args); \
} while (0)

struct lgdt330x_state
{
        struct i2c_adapter* i2c;

        /* Configuration settings */
        const struct lgdt330x_config* config;

        struct dvb_frontend frontend;

        /* Demodulator private data */
        enum fe_modulation current_modulation;
        u32 snr; /* Result of last SNR calculation */

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

static int i2c_write_demod_bytes (struct lgdt330x_state* state,
                                  u8 *buf, /* data bytes to send */
                                  int len  /* number of bytes to send */ )
{
        struct i2c_msg msg =
                { .addr = state->config->demod_address,
                  .flags = 0,
                  .buf = buf,
                  .len = 2 };
        int i;
        int err;

        for (i=0; i<len-1; i+=2){
                if ((err = i2c_transfer(state->i2c, &msg, 1)) != 1) {
                        printk(KERN_WARNING "lgdt330x: %s error (addr %02x <- %02x, err = %i)\n", __func__, msg.buf[0], msg.buf[1], err);
                        if (err < 0)
                                return err;
                        else
                                return -EREMOTEIO;
                }
                msg.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->config->demod_address,
                  .flags = 0, .buf = wr,  .len = 1 },
                { .addr = state->config->demod_address,
                  .flags = I2C_M_RD, .buf = buf, .len = len },
        };
        int ret;
        ret = i2c_transfer(state->i2c, msg, 2);
        if (ret != 2) {
                printk(KERN_WARNING "lgdt330x: %s: addr 0x%02x select 0x%02x error (ret == %i)\n", __func__, state->config->demod_address, reg, ret);
                if (ret >= 0)
                        ret = -EIO;
        } else {
                ret = 0;
        }
        return ret;
}

/* Software reset */
static int lgdt3302_SwReset(struct lgdt330x_state* state)
{
        u8 ret;
        u8 reset[] = {
                IRQ_MASK,
                0x00 /* bit 6 is active low software reset
                      * bits 5-0 are 1 to mask interrupts */
        };

        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_SwReset(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_SwReset(struct lgdt330x_state* state)
{
        switch (state->config->demod_chip) {
        case LGDT3302:
                return lgdt3302_SwReset(state);
        case LGDT3303:
                return lgdt3303_SwReset(state);
        default:
                return -ENODEV;
        }
}

static int lgdt330x_init(struct dvb_frontend* fe)
{
        /* 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. */

        /*
         * Array of byte pairs <address, value>
         * to initialize each different chip
         */
        static u8 lgdt3302_init_data[] = {
                /* Use 50MHz parameter 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 u8 lgdt3303_init_data[] = {
                0x4c, 0x14
        };

        static u8 flip_1_lgdt3303_init_data[] = {
                0x4c, 0x14,
                0x87, 0xf3
        };

        static u8 flip_2_lgdt3303_init_data[] = {
                0x4c, 0x14,
                0x87, 0xda
        };

        struct lgdt330x_state* state = fe->demodulator_priv;
        char  *chip_name;
        int    err;

        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";
                printk (KERN_WARNING "Only LGDT3302 and LGDT3303 are supported chips.\n");
                err = -ENODEV;
        }
        dprintk("%s entered as %s\n", __func__, chip_name);
        if (err < 0)
                return err;
        return lgdt330x_SwReset(state);
}

static int lgdt330x_read_ber(struct dvb_frontend* fe, u32* ber)
{
        *ber = 0; /* Not supplied by the demod chips */
        return 0;
}

static int lgdt330x_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
{
        struct lgdt330x_state* state = fe->demodulator_priv;
        int err;
        u8 buf[2];

        *ucblocks = 0;

        switch (state->config->demod_chip) {
        case LGDT3302:
                err = i2c_read_demod_bytes(state, LGDT3302_PACKET_ERR_COUNTER1,
                                           buf, sizeof(buf));
                break;
        case LGDT3303:
                err = i2c_read_demod_bytes(state, LGDT3303_PACKET_ERR_COUNTER1,
                                           buf, sizeof(buf));
                break;
        default:
                printk(KERN_WARNING
                       "Only LGDT3302 and LGDT3303 are supported chips.\n");
                err = -ENODEV;
        }
        if (err < 0)
                return err;

        *ucblocks = (buf[0] << 8) | buf[1];
        return 0;
}

static int lgdt330x_set_parameters(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        /*
         * Array of byte pairs <address, value>
         * to initialize 8VSB for lgdt3303 chip 50 MHz IF
         */
        static 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 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 };

        struct lgdt330x_state* state = fe->demodulator_priv;

        static 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("%s: VSB_8 MODE\n", __func__);

                        /* 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("%s: QAM_64 MODE\n", __func__);

                        /* 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("%s: QAM_256 MODE\n", __func__);

                        /* 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:
                        printk(KERN_WARNING "lgdt330x: %s: Modulation type(%d) UNSUPPORTED\n", __func__, p->modulation);
                        return -1;
                }
                if (err < 0)
                        printk(KERN_WARNING "lgdt330x: %s: error blasting "
                               "bytes to lgdt3303 for modulation type(%d)\n",
                               __func__, p->modulation);

                /*
                 * select serial or parallel MPEG harware 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_SwReset(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;
}

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

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

        /* AGC status register */
        i2c_read_demod_bytes(state, AGC_STATUS, buf, 1);
        dprintk("%s: AGC_STATUS = 0x%02x\n", __func__, 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("%s: TOP_CONTROL = 0x%02x, IRO_MASK = 0x%02x, IRQ_STATUS = 0x%02x\n", __func__, 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;
                *status |= FE_HAS_VITERBI;
        }

        /* Carrier Recovery Lock Status Register */
        i2c_read_demod_bytes(state, CARRIER_LOCK, buf, 1);
        dprintk("%s: CARRIER_LOCK = 0x%02x\n", __func__, 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:
                printk(KERN_WARNING "lgdt330x: %s: Modulation set to unsupported value\n", __func__);
        }

        return 0;
}

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

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

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

        dprintk("%s: AGC_STATUS = 0x%02x\n", __func__, 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("%s: CARRIER_LOCK = 0x%02x\n", __func__, 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);
                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);
                if ((buf[0] & 0x02) == 0x00)
                        *status |= FE_HAS_SYNC;
                if ((buf[0] & 0x01) == 0x01) {
                        *status |= FE_HAS_LOCK;
                        *status |= FE_HAS_VITERBI;
                }
                break;
        default:
                printk(KERN_WARNING "lgdt330x: %s: Modulation set to unsupported value\n", __func__);
        }
        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, u16* snr)
{
        struct lgdt330x_state* state = (struct lgdt330x_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:
                printk(KERN_ERR "lgdt330x: %s: Modulation set to unsupported value\n",
                       __func__);
                return -EREMOTEIO; /* return -EDRIVER_IS_GIBBERED; */
        }

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

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

        return 0;
}

static int lgdt3303_read_snr(struct dvb_frontend* fe, u16* snr)
{
        struct lgdt330x_state* state = (struct lgdt330x_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:
                printk(KERN_ERR "lgdt330x: %s: Modulation set to unsupported value\n",
                       __func__);
                return -EREMOTEIO; /* return -EDRIVER_IS_GIBBERED; */
        }

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

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

        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 = (struct lgdt330x_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 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 = (struct lgdt330x_state*) fe->demodulator_priv;
        kfree(state);
}

static struct dvb_frontend_ops lgdt3302_ops;
static struct dvb_frontend_ops lgdt3303_ops;

struct dvb_frontend* lgdt330x_attach(const struct lgdt330x_config* config,
                                     struct i2c_adapter* i2c)
{
        struct lgdt330x_state* state = NULL;
        u8 buf[1];

        /* Allocate memory for the internal state */
        state = kzalloc(sizeof(struct lgdt330x_state), GFP_KERNEL);
        if (state == NULL)
                goto error;

        /* Setup the state */
        state->config = config;
        state->i2c = i2c;

        /* Create dvb_frontend */
        switch (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;

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

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

        return &state->frontend;

error:
        kfree(state);
        dprintk("%s: ERROR\n",__func__);
        return NULL;
}

static struct dvb_frontend_ops lgdt3302_ops = {
        .delsys = { SYS_ATSC, SYS_DVBC_ANNEX_B },
        .info = {
                .name= "LG Electronics LGDT3302 VSB/QAM Frontend",
                .frequency_min= 54000000,
                .frequency_max= 858000000,
                .frequency_stepsize= 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_ber             = lgdt330x_read_ber,
        .read_signal_strength = lgdt330x_read_signal_strength,
        .read_snr             = lgdt3302_read_snr,
        .read_ucblocks        = lgdt330x_read_ucblocks,
        .release              = lgdt330x_release,
};

static struct dvb_frontend_ops lgdt3303_ops = {
        .delsys = { SYS_ATSC, SYS_DVBC_ANNEX_B },
        .info = {
                .name= "LG Electronics LGDT3303 VSB/QAM Frontend",
                .frequency_min= 54000000,
                .frequency_max= 858000000,
                .frequency_stepsize= 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_ber             = lgdt330x_read_ber,
        .read_signal_strength = lgdt330x_read_signal_strength,
        .read_snr             = lgdt3303_read_snr,
        .read_ucblocks        = lgdt330x_read_ucblocks,
        .release              = lgdt330x_release,
};

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

EXPORT_SYMBOL(lgdt330x_attach);