/*
 * Fitipower FC0012 tuner driver
 *
 * Copyright (C) 2012 Hans-Frieder Vogt <hfvogt@gmx.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.
 */

#include "fc0012.h"
#include "fc0012-priv.h"

static int fc0012_writereg(struct fc0012_priv *priv, u8 reg, u8 val)
{
        u8 buf[2] = {reg, val};
        struct i2c_msg msg = {
                .addr = priv->cfg->i2c_address, .flags = 0, .buf = buf, .len = 2
        };

        if (i2c_transfer(priv->i2c, &msg, 1) != 1) {
                dev_err(&priv->i2c->dev,
                        "%s: I2C write reg failed, reg: %02x, val: %02x\n",
                        KBUILD_MODNAME, reg, val);
                return -EREMOTEIO;
        }
        return 0;
}

static int fc0012_readreg(struct fc0012_priv *priv, u8 reg, u8 *val)
{
        struct i2c_msg msg[2] = {
                { .addr = priv->cfg->i2c_address, .flags = 0,
                        .buf = &reg, .len = 1 },
                { .addr = priv->cfg->i2c_address, .flags = I2C_M_RD,
                        .buf = val, .len = 1 },
        };

        if (i2c_transfer(priv->i2c, msg, 2) != 2) {
                dev_err(&priv->i2c->dev,
                        "%s: I2C read reg failed, reg: %02x\n",
                        KBUILD_MODNAME, reg);
                return -EREMOTEIO;
        }
        return 0;
}

static void fc0012_release(struct dvb_frontend *fe)
{
        kfree(fe->tuner_priv);
        fe->tuner_priv = NULL;
}

static int fc0012_init(struct dvb_frontend *fe)
{
        struct fc0012_priv *priv = fe->tuner_priv;
        int i, ret = 0;
        unsigned char reg[] = {
                0x00,   /* dummy reg. 0 */
                0x05,   /* reg. 0x01 */
                0x10,   /* reg. 0x02 */
                0x00,   /* reg. 0x03 */
                0x00,   /* reg. 0x04 */
                0x0f,   /* reg. 0x05: may also be 0x0a */
                0x00,   /* reg. 0x06: divider 2, VCO slow */
                0x00,   /* reg. 0x07: may also be 0x0f */
                0xff,   /* reg. 0x08: AGC Clock divide by 256, AGC gain 1/256,
                           Loop Bw 1/8 */
                0x6e,   /* reg. 0x09: Disable LoopThrough, Enable LoopThrough: 0x6f */
                0xb8,   /* reg. 0x0a: Disable LO Test Buffer */
                0x82,   /* reg. 0x0b: Output Clock is same as clock frequency,
                           may also be 0x83 */
                0xfc,   /* reg. 0x0c: depending on AGC Up-Down mode, may need 0xf8 */
                0x02,   /* reg. 0x0d: AGC Not Forcing & LNA Forcing, 0x02 for DVB-T */
                0x00,   /* reg. 0x0e */
                0x00,   /* reg. 0x0f */
                0x00,   /* reg. 0x10: may also be 0x0d */
                0x00,   /* reg. 0x11 */
                0x1f,   /* reg. 0x12: Set to maximum gain */
                0x08,   /* reg. 0x13: Set to Middle Gain: 0x08,
                           Low Gain: 0x00, High Gain: 0x10, enable IX2: 0x80 */
                0x00,   /* reg. 0x14 */
                0x04,   /* reg. 0x15: Enable LNA COMPS */
        };

        switch (priv->cfg->xtal_freq) {
        case FC_XTAL_27_MHZ:
        case FC_XTAL_28_8_MHZ:
                reg[0x07] |= 0x20;
                break;
        case FC_XTAL_36_MHZ:
        default:
                break;
        }

        if (priv->cfg->dual_master)
                reg[0x0c] |= 0x02;

        if (priv->cfg->loop_through)
                reg[0x09] |= 0x01;

        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */

        for (i = 1; i < sizeof(reg); i++) {
                ret = fc0012_writereg(priv, i, reg[i]);
                if (ret)
                        break;
        }

        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */

        if (ret)
                dev_err(&priv->i2c->dev, "%s: fc0012_writereg failed: %d\n",
                                KBUILD_MODNAME, ret);

        return ret;
}

static int fc0012_set_params(struct dvb_frontend *fe)
{
        struct fc0012_priv *priv = fe->tuner_priv;
        int i, ret = 0;
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        u32 freq = p->frequency / 1000;
        u32 delsys = p->delivery_system;
        unsigned char reg[7], am, pm, multi, tmp;
        unsigned long f_vco;
        unsigned short xtal_freq_khz_2, xin, xdiv;
        bool vco_select = false;

        if (fe->callback) {
                ret = fe->callback(priv->i2c, DVB_FRONTEND_COMPONENT_TUNER,
                        FC_FE_CALLBACK_VHF_ENABLE, (freq > 300000 ? 0 : 1));
                if (ret)
                        goto exit;
        }

        switch (priv->cfg->xtal_freq) {
        case FC_XTAL_27_MHZ:
                xtal_freq_khz_2 = 27000 / 2;
                break;
        case FC_XTAL_36_MHZ:
                xtal_freq_khz_2 = 36000 / 2;
                break;
        case FC_XTAL_28_8_MHZ:
        default:
                xtal_freq_khz_2 = 28800 / 2;
                break;
        }

        /* select frequency divider and the frequency of VCO */
        if (freq < 37084) {             /* freq * 96 < 3560000 */
                multi = 96;
                reg[5] = 0x82;
                reg[6] = 0x00;
        } else if (freq < 55625) {      /* freq * 64 < 3560000 */
                multi = 64;
                reg[5] = 0x82;
                reg[6] = 0x02;
        } else if (freq < 74167) {      /* freq * 48 < 3560000 */
                multi = 48;
                reg[5] = 0x42;
                reg[6] = 0x00;
        } else if (freq < 111250) {     /* freq * 32 < 3560000 */
                multi = 32;
                reg[5] = 0x42;
                reg[6] = 0x02;
        } else if (freq < 148334) {     /* freq * 24 < 3560000 */
                multi = 24;
                reg[5] = 0x22;
                reg[6] = 0x00;
        } else if (freq < 222500) {     /* freq * 16 < 3560000 */
                multi = 16;
                reg[5] = 0x22;
                reg[6] = 0x02;
        } else if (freq < 296667) {     /* freq * 12 < 3560000 */
                multi = 12;
                reg[5] = 0x12;
                reg[6] = 0x00;
        } else if (freq < 445000) {     /* freq * 8 < 3560000 */
                multi = 8;
                reg[5] = 0x12;
                reg[6] = 0x02;
        } else if (freq < 593334) {     /* freq * 6 < 3560000 */
                multi = 6;
                reg[5] = 0x0a;
                reg[6] = 0x00;
        } else {
                multi = 4;
                reg[5] = 0x0a;
                reg[6] = 0x02;
        }

        f_vco = freq * multi;

        if (f_vco >= 3060000) {
                reg[6] |= 0x08;
                vco_select = true;
        }

        if (freq >= 45000) {
                /* From divided value (XDIV) determined the FA and FP value */
                xdiv = (unsigned short)(f_vco / xtal_freq_khz_2);
                if ((f_vco - xdiv * xtal_freq_khz_2) >= (xtal_freq_khz_2 / 2))
                        xdiv++;

                pm = (unsigned char)(xdiv / 8);
                am = (unsigned char)(xdiv - (8 * pm));

                if (am < 2) {
                        reg[1] = am + 8;
                        reg[2] = pm - 1;
                } else {
                        reg[1] = am;
                        reg[2] = pm;
                }
        } else {
                /* fix for frequency less than 45 MHz */
                reg[1] = 0x06;
                reg[2] = 0x11;
        }

        /* fix clock out */
        reg[6] |= 0x20;

        /* From VCO frequency determines the XIN ( fractional part of Delta
           Sigma PLL) and divided value (XDIV) */
        xin = (unsigned short)(f_vco - (f_vco / xtal_freq_khz_2) * xtal_freq_khz_2);
        xin = (xin << 15) / xtal_freq_khz_2;
        if (xin >= 16384)
                xin += 32768;

        reg[3] = xin >> 8;      /* xin with 9 bit resolution */
        reg[4] = xin & 0xff;

        if (delsys == SYS_DVBT) {
                reg[6] &= 0x3f; /* bits 6 and 7 describe the bandwidth */
                switch (p->bandwidth_hz) {
                case 6000000:
                        reg[6] |= 0x80;
                        break;
                case 7000000:
                        reg[6] |= 0x40;
                        break;
                case 8000000:
                default:
                        break;
                }
        } else {
                dev_err(&priv->i2c->dev, "%s: modulation type not supported!\n",
                                KBUILD_MODNAME);
                return -EINVAL;
        }

        /* modified for Realtek demod */
        reg[5] |= 0x07;

        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */

        for (i = 1; i <= 6; i++) {
                ret = fc0012_writereg(priv, i, reg[i]);
                if (ret)
                        goto exit;
        }

        /* VCO Calibration */
        ret = fc0012_writereg(priv, 0x0e, 0x80);
        if (!ret)
                ret = fc0012_writereg(priv, 0x0e, 0x00);

        /* VCO Re-Calibration if needed */
        if (!ret)
                ret = fc0012_writereg(priv, 0x0e, 0x00);

        if (!ret) {
                msleep(10);
                ret = fc0012_readreg(priv, 0x0e, &tmp);
        }
        if (ret)
                goto exit;

        /* vco selection */
        tmp &= 0x3f;

        if (vco_select) {
                if (tmp > 0x3c) {
                        reg[6] &= ~0x08;
                        ret = fc0012_writereg(priv, 0x06, reg[6]);
                        if (!ret)
                                ret = fc0012_writereg(priv, 0x0e, 0x80);
                        if (!ret)
                                ret = fc0012_writereg(priv, 0x0e, 0x00);
                }
        } else {
                if (tmp < 0x02) {
                        reg[6] |= 0x08;
                        ret = fc0012_writereg(priv, 0x06, reg[6]);
                        if (!ret)
                                ret = fc0012_writereg(priv, 0x0e, 0x80);
                        if (!ret)
                                ret = fc0012_writereg(priv, 0x0e, 0x00);
                }
        }

        priv->frequency = p->frequency;
        priv->bandwidth = p->bandwidth_hz;

exit:
        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */
        if (ret)
                dev_warn(&priv->i2c->dev, "%s: %s failed: %d\n",
                                KBUILD_MODNAME, __func__, ret);
        return ret;
}

static int fc0012_get_frequency(struct dvb_frontend *fe, u32 *frequency)
{
        struct fc0012_priv *priv = fe->tuner_priv;
        *frequency = priv->frequency;
        return 0;
}

static int fc0012_get_if_frequency(struct dvb_frontend *fe, u32 *frequency)
{
        *frequency = 0; /* Zero-IF */
        return 0;
}

static int fc0012_get_bandwidth(struct dvb_frontend *fe, u32 *bandwidth)
{
        struct fc0012_priv *priv = fe->tuner_priv;
        *bandwidth = priv->bandwidth;
        return 0;
}

#define INPUT_ADC_LEVEL -8

static int fc0012_get_rf_strength(struct dvb_frontend *fe, u16 *strength)
{
        struct fc0012_priv *priv = fe->tuner_priv;
        int ret;
        unsigned char tmp;
        int int_temp, lna_gain, int_lna, tot_agc_gain, power;
        static const int fc0012_lna_gain_table[] = {
                /* low gain */
                -63, -58, -99, -73,
                -63, -65, -54, -60,
                /* middle gain */
                 71,  70,  68,  67,
                 65,  63,  61,  58,
                /* high gain */
                197, 191, 188, 186,
                184, 182, 181, 179,
        };

        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 1); /* open I2C-gate */

        ret = fc0012_writereg(priv, 0x12, 0x00);
        if (ret)
                goto err;

        ret = fc0012_readreg(priv, 0x12, &tmp);
        if (ret)
                goto err;
        int_temp = tmp;

        ret = fc0012_readreg(priv, 0x13, &tmp);
        if (ret)
                goto err;
        lna_gain = tmp & 0x1f;

        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */

        if (lna_gain < ARRAY_SIZE(fc0012_lna_gain_table)) {
                int_lna = fc0012_lna_gain_table[lna_gain];
                tot_agc_gain = (abs((int_temp >> 5) - 7) - 2 +
                                (int_temp & 0x1f)) * 2;
                power = INPUT_ADC_LEVEL - tot_agc_gain - int_lna / 10;

                if (power >= 45)
                        *strength = 255;        /* 100% */
                else if (power < -95)
                        *strength = 0;
                else
                        *strength = (power + 95) * 255 / 140;

                *strength |= *strength << 8;
        } else {
                ret = -1;
        }

        goto exit;

err:
        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0); /* close I2C-gate */
exit:
        if (ret)
                dev_warn(&priv->i2c->dev, "%s: %s failed: %d\n",
                                KBUILD_MODNAME, __func__, ret);
        return ret;
}

static const struct dvb_tuner_ops fc0012_tuner_ops = {
        .info = {
                .name              = "Fitipower FC0012",

                .frequency_min_hz  =  37 * MHz, /* estimate */
                .frequency_max_hz  = 862 * MHz, /* estimate */
        },

        .release        = fc0012_release,

        .init           = fc0012_init,

        .set_params     = fc0012_set_params,

        .get_frequency  = fc0012_get_frequency,
        .get_if_frequency = fc0012_get_if_frequency,
        .get_bandwidth  = fc0012_get_bandwidth,

        .get_rf_strength = fc0012_get_rf_strength,
};

struct dvb_frontend *fc0012_attach(struct dvb_frontend *fe,
        struct i2c_adapter *i2c, const struct fc0012_config *cfg)
{
        struct fc0012_priv *priv;
        int ret;
        u8 chip_id;

        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 1);

        priv = kzalloc(sizeof(struct fc0012_priv), GFP_KERNEL);
        if (!priv) {
                ret = -ENOMEM;
                dev_err(&i2c->dev, "%s: kzalloc() failed\n", KBUILD_MODNAME);
                goto err;
        }

        priv->cfg = cfg;
        priv->i2c = i2c;

        /* check if the tuner is there */
        ret = fc0012_readreg(priv, 0x00, &chip_id);
        if (ret < 0)
                goto err;

        dev_dbg(&i2c->dev, "%s: chip_id=%02x\n", __func__, chip_id);

        switch (chip_id) {
        case 0xa1:
                break;
        default:
                ret = -ENODEV;
                goto err;
        }

        dev_info(&i2c->dev, "%s: Fitipower FC0012 successfully identified\n",
                        KBUILD_MODNAME);

        if (priv->cfg->loop_through) {
                ret = fc0012_writereg(priv, 0x09, 0x6f);
                if (ret < 0)
                        goto err;
        }

        /*
         * TODO: Clock out en or div?
         * For dual tuner configuration clearing bit [0] is required.
         */
        if (priv->cfg->clock_out) {
                ret =  fc0012_writereg(priv, 0x0b, 0x82);
                if (ret < 0)
                        goto err;
        }

        fe->tuner_priv = priv;
        memcpy(&fe->ops.tuner_ops, &fc0012_tuner_ops,
                sizeof(struct dvb_tuner_ops));

err:
        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0);

        if (ret) {
                dev_dbg(&i2c->dev, "%s: failed: %d\n", __func__, ret);
                kfree(priv);
                return NULL;
        }

        return fe;
}
EXPORT_SYMBOL(fc0012_attach);

MODULE_DESCRIPTION("Fitipower FC0012 silicon tuner driver");
MODULE_AUTHOR("Hans-Frieder Vogt <hfvogt@gmx.net>");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.6");