/*
    Montage Technology TS2020 - Silicon Tuner driver
    Copyright (C) 2009-2012 Konstantin Dimitrov <kosio.dimitrov@gmail.com>

    Copyright (C) 2009-2012 TurboSight.com

    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 "dvb_frontend.h"
#include "ts2020.h"
#include <linux/regmap.h>
#include <linux/math64.h>

#define TS2020_XTAL_FREQ   27000 /* in kHz */
#define FREQ_OFFSET_LOW_SYM_RATE 3000

struct ts2020_priv {
        struct i2c_client *client;
        struct mutex regmap_mutex;
        struct regmap_config regmap_config;
        struct regmap *regmap;
        struct dvb_frontend *fe;
        struct delayed_work stat_work;
        int (*get_agc_pwm)(struct dvb_frontend *fe, u8 *_agc_pwm);
        /* i2c details */
        struct i2c_adapter *i2c;
        int i2c_address;
        bool loop_through:1;
        u8 clk_out:2;
        u8 clk_out_div:5;
        bool dont_poll:1;
        u32 frequency_div; /* LO output divider switch frequency */
        u32 frequency_khz; /* actual used LO frequency */
#define TS2020_M88TS2020 0
#define TS2020_M88TS2022 1
        u8 tuner;
};

struct ts2020_reg_val {
        u8 reg;
        u8 val;
};

static void ts2020_stat_work(struct work_struct *work);

static void ts2020_release(struct dvb_frontend *fe)
{
        struct ts2020_priv *priv = fe->tuner_priv;
        struct i2c_client *client = priv->client;

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

        i2c_unregister_device(client);
}

static int ts2020_sleep(struct dvb_frontend *fe)
{
        struct ts2020_priv *priv = fe->tuner_priv;
        int ret;
        u8 u8tmp;

        if (priv->tuner == TS2020_M88TS2020)
                u8tmp = 0x0a; /* XXX: probably wrong */
        else
                u8tmp = 0x00;

        ret = regmap_write(priv->regmap, u8tmp, 0x00);
        if (ret < 0)
                return ret;

        /* stop statistics polling */
        if (!priv->dont_poll)
                cancel_delayed_work_sync(&priv->stat_work);
        return 0;
}

static int ts2020_init(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        struct ts2020_priv *priv = fe->tuner_priv;
        int i;
        u8 u8tmp;

        if (priv->tuner == TS2020_M88TS2020) {
                regmap_write(priv->regmap, 0x42, 0x73);
                regmap_write(priv->regmap, 0x05, priv->clk_out_div);
                regmap_write(priv->regmap, 0x20, 0x27);
                regmap_write(priv->regmap, 0x07, 0x02);
                regmap_write(priv->regmap, 0x11, 0xff);
                regmap_write(priv->regmap, 0x60, 0xf9);
                regmap_write(priv->regmap, 0x08, 0x01);
                regmap_write(priv->regmap, 0x00, 0x41);
        } else {
                static const struct ts2020_reg_val reg_vals[] = {
                        {0x7d, 0x9d},
                        {0x7c, 0x9a},
                        {0x7a, 0x76},
                        {0x3b, 0x01},
                        {0x63, 0x88},
                        {0x61, 0x85},
                        {0x22, 0x30},
                        {0x30, 0x40},
                        {0x20, 0x23},
                        {0x24, 0x02},
                        {0x12, 0xa0},
                };

                regmap_write(priv->regmap, 0x00, 0x01);
                regmap_write(priv->regmap, 0x00, 0x03);

                switch (priv->clk_out) {
                case TS2020_CLK_OUT_DISABLED:
                        u8tmp = 0x60;
                        break;
                case TS2020_CLK_OUT_ENABLED:
                        u8tmp = 0x70;
                        regmap_write(priv->regmap, 0x05, priv->clk_out_div);
                        break;
                case TS2020_CLK_OUT_ENABLED_XTALOUT:
                        u8tmp = 0x6c;
                        break;
                default:
                        u8tmp = 0x60;
                        break;
                }

                regmap_write(priv->regmap, 0x42, u8tmp);

                if (priv->loop_through)
                        u8tmp = 0xec;
                else
                        u8tmp = 0x6c;

                regmap_write(priv->regmap, 0x62, u8tmp);

                for (i = 0; i < ARRAY_SIZE(reg_vals); i++)
                        regmap_write(priv->regmap, reg_vals[i].reg,
                                     reg_vals[i].val);
        }

        /* Initialise v5 stats here */
        c->strength.len = 1;
        c->strength.stat[0].scale = FE_SCALE_DECIBEL;
        c->strength.stat[0].uvalue = 0;

        /* Start statistics polling by invoking the work function */
        ts2020_stat_work(&priv->stat_work.work);
        return 0;
}

static int ts2020_tuner_gate_ctrl(struct dvb_frontend *fe, u8 offset)
{
        struct ts2020_priv *priv = fe->tuner_priv;
        int ret;
        ret = regmap_write(priv->regmap, 0x51, 0x1f - offset);
        ret |= regmap_write(priv->regmap, 0x51, 0x1f);
        ret |= regmap_write(priv->regmap, 0x50, offset);
        ret |= regmap_write(priv->regmap, 0x50, 0x00);
        msleep(20);
        return ret;
}

static int ts2020_set_tuner_rf(struct dvb_frontend *fe)
{
        struct ts2020_priv *dev = fe->tuner_priv;
        int ret;
        unsigned int utmp;

        ret = regmap_read(dev->regmap, 0x3d, &utmp);
        utmp &= 0x7f;
        if (utmp < 0x16)
                utmp = 0xa1;
        else if (utmp == 0x16)
                utmp = 0x99;
        else
                utmp = 0xf9;

        regmap_write(dev->regmap, 0x60, utmp);
        ret = ts2020_tuner_gate_ctrl(fe, 0x08);

        return ret;
}

static int ts2020_set_params(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        struct ts2020_priv *priv = fe->tuner_priv;
        int ret;
        unsigned int utmp;
        u32 f3db, gdiv28;
        u16 u16tmp, value, lpf_coeff;
        u8 buf[3], reg10, lpf_mxdiv, mlpf_max, mlpf_min, nlpf;
        unsigned int f_ref_khz, f_vco_khz, div_ref, div_out, pll_n;
        unsigned int frequency_khz = c->frequency;

        /*
         * Integer-N PLL synthesizer
         * kHz is used for all calculations to keep calculations within 32-bit
         */
        f_ref_khz = TS2020_XTAL_FREQ;
        div_ref = DIV_ROUND_CLOSEST(f_ref_khz, 2000);

        /* select LO output divider */
        if (frequency_khz < priv->frequency_div) {
                div_out = 4;
                reg10 = 0x10;
        } else {
                div_out = 2;
                reg10 = 0x00;
        }

        f_vco_khz = frequency_khz * div_out;
        pll_n = f_vco_khz * div_ref / f_ref_khz;
        pll_n += pll_n % 2;
        priv->frequency_khz = pll_n * f_ref_khz / div_ref / div_out;

        pr_debug("frequency=%u offset=%d f_vco_khz=%u pll_n=%u div_ref=%u div_out=%u\n",
                 priv->frequency_khz, priv->frequency_khz - c->frequency,
                 f_vco_khz, pll_n, div_ref, div_out);

        if (priv->tuner == TS2020_M88TS2020) {
                lpf_coeff = 2766;
                reg10 |= 0x01;
                ret = regmap_write(priv->regmap, 0x10, reg10);
        } else {
                lpf_coeff = 3200;
                reg10 |= 0x0b;
                ret = regmap_write(priv->regmap, 0x10, reg10);
                ret |= regmap_write(priv->regmap, 0x11, 0x40);
        }

        u16tmp = pll_n - 1024;
        buf[0] = (u16tmp >> 8) & 0xff;
        buf[1] = (u16tmp >> 0) & 0xff;
        buf[2] = div_ref - 8;

        ret |= regmap_write(priv->regmap, 0x01, buf[0]);
        ret |= regmap_write(priv->regmap, 0x02, buf[1]);
        ret |= regmap_write(priv->regmap, 0x03, buf[2]);

        ret |= ts2020_tuner_gate_ctrl(fe, 0x10);
        if (ret < 0)
                return -ENODEV;

        ret |= ts2020_tuner_gate_ctrl(fe, 0x08);

        /* Tuner RF */
        if (priv->tuner == TS2020_M88TS2020)
                ret |= ts2020_set_tuner_rf(fe);

        gdiv28 = (TS2020_XTAL_FREQ / 1000 * 1694 + 500) / 1000;
        ret |= regmap_write(priv->regmap, 0x04, gdiv28 & 0xff);
        ret |= ts2020_tuner_gate_ctrl(fe, 0x04);
        if (ret < 0)
                return -ENODEV;

        if (priv->tuner == TS2020_M88TS2022) {
                ret = regmap_write(priv->regmap, 0x25, 0x00);
                ret |= regmap_write(priv->regmap, 0x27, 0x70);
                ret |= regmap_write(priv->regmap, 0x41, 0x09);
                ret |= regmap_write(priv->regmap, 0x08, 0x0b);
                if (ret < 0)
                        return -ENODEV;
        }

        regmap_read(priv->regmap, 0x26, &utmp);
        value = utmp;

        f3db = (c->bandwidth_hz / 1000 / 2) + 2000;
        f3db += FREQ_OFFSET_LOW_SYM_RATE; /* FIXME: ~always too wide filter */
        f3db = clamp(f3db, 7000U, 40000U);

        gdiv28 = gdiv28 * 207 / (value * 2 + 151);
        mlpf_max = gdiv28 * 135 / 100;
        mlpf_min = gdiv28 * 78 / 100;
        if (mlpf_max > 63)
                mlpf_max = 63;

        nlpf = (f3db * gdiv28 * 2 / lpf_coeff /
                (TS2020_XTAL_FREQ / 1000)  + 1) / 2;
        if (nlpf > 23)
                nlpf = 23;
        if (nlpf < 1)
                nlpf = 1;

        lpf_mxdiv = (nlpf * (TS2020_XTAL_FREQ / 1000)
                * lpf_coeff * 2  / f3db + 1) / 2;

        if (lpf_mxdiv < mlpf_min) {
                nlpf++;
                lpf_mxdiv = (nlpf * (TS2020_XTAL_FREQ / 1000)
                        * lpf_coeff * 2  / f3db + 1) / 2;
        }

        if (lpf_mxdiv > mlpf_max)
                lpf_mxdiv = mlpf_max;

        ret = regmap_write(priv->regmap, 0x04, lpf_mxdiv);
        ret |= regmap_write(priv->regmap, 0x06, nlpf);

        ret |= ts2020_tuner_gate_ctrl(fe, 0x04);

        ret |= ts2020_tuner_gate_ctrl(fe, 0x01);

        msleep(80);

        return (ret < 0) ? -EINVAL : 0;
}

static int ts2020_get_frequency(struct dvb_frontend *fe, u32 *frequency)
{
        struct ts2020_priv *priv = fe->tuner_priv;

        *frequency = priv->frequency_khz;
        return 0;
}

static int ts2020_get_if_frequency(struct dvb_frontend *fe, u32 *frequency)
{
        *frequency = 0; /* Zero-IF */
        return 0;
}

/*
 * Get the tuner gain.
 * @fe: The front end for which we're determining the gain
 * @v_agc: The voltage of the AGC from the demodulator (0-2600mV)
 * @_gain: Where to store the gain (in 0.001dB units)
 *
 * Returns 0 or a negative error code.
 */
static int ts2020_read_tuner_gain(struct dvb_frontend *fe, unsigned v_agc,
                                  __s64 *_gain)
{
        struct ts2020_priv *priv = fe->tuner_priv;
        unsigned long gain1, gain2, gain3;
        unsigned utmp;
        int ret;

        /* Read the RF gain */
        ret = regmap_read(priv->regmap, 0x3d, &utmp);
        if (ret < 0)
                return ret;
        gain1 = utmp & 0x1f;

        /* Read the baseband gain */
        ret = regmap_read(priv->regmap, 0x21, &utmp);
        if (ret < 0)
                return ret;
        gain2 = utmp & 0x1f;

        switch (priv->tuner) {
        case TS2020_M88TS2020:
                gain1 = clamp_t(long, gain1, 0, 15);
                gain2 = clamp_t(long, gain2, 0, 13);
                v_agc = clamp_t(long, v_agc, 400, 1100);

                *_gain = -(gain1 * 2330 +
                           gain2 * 3500 +
                           v_agc * 24 / 10 * 10 +
                           10000);
                /* gain in range -19600 to -116850 in units of 0.001dB */
                break;

        case TS2020_M88TS2022:
                ret = regmap_read(priv->regmap, 0x66, &utmp);
                if (ret < 0)
                        return ret;
                gain3 = (utmp >> 3) & 0x07;

                gain1 = clamp_t(long, gain1, 0, 15);
                gain2 = clamp_t(long, gain2, 2, 16);
                gain3 = clamp_t(long, gain3, 0, 6);
                v_agc = clamp_t(long, v_agc, 600, 1600);

                *_gain = -(gain1 * 2650 +
                           gain2 * 3380 +
                           gain3 * 2850 +
                           v_agc * 176 / 100 * 10 -
                           30000);
                /* gain in range -47320 to -158950 in units of 0.001dB */
                break;
        }

        return 0;
}

/*
 * Get the AGC information from the demodulator and use that to calculate the
 * tuner gain.
 */
static int ts2020_get_tuner_gain(struct dvb_frontend *fe, __s64 *_gain)
{
        struct ts2020_priv *priv = fe->tuner_priv;
        int v_agc = 0, ret;
        u8 agc_pwm;

        /* Read the AGC PWM rate from the demodulator */
        if (priv->get_agc_pwm) {
                ret = priv->get_agc_pwm(fe, &agc_pwm);
                if (ret < 0)
                        return ret;

                switch (priv->tuner) {
                case TS2020_M88TS2020:
                        v_agc = (int)agc_pwm * 20 - 1166;
                        break;
                case TS2020_M88TS2022:
                        v_agc = (int)agc_pwm * 16 - 670;
                        break;
                }

                if (v_agc < 0)
                        v_agc = 0;
        }

        return ts2020_read_tuner_gain(fe, v_agc, _gain);
}

/*
 * Gather statistics on a regular basis
 */
static void ts2020_stat_work(struct work_struct *work)
{
        struct ts2020_priv *priv = container_of(work, struct ts2020_priv,
                                               stat_work.work);
        struct i2c_client *client = priv->client;
        struct dtv_frontend_properties *c = &priv->fe->dtv_property_cache;
        int ret;

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

        ret = ts2020_get_tuner_gain(priv->fe, &c->strength.stat[0].svalue);
        if (ret < 0)
                goto err;

        c->strength.stat[0].scale = FE_SCALE_DECIBEL;

        if (!priv->dont_poll)
                schedule_delayed_work(&priv->stat_work, msecs_to_jiffies(2000));
        return;
err:
        dev_dbg(&client->dev, "failed=%d\n", ret);
}

/*
 * Read TS2020 signal strength in v3 format.
 */
static int ts2020_read_signal_strength(struct dvb_frontend *fe,
                                       u16 *_signal_strength)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        struct ts2020_priv *priv = fe->tuner_priv;
        unsigned strength;
        __s64 gain;

        if (priv->dont_poll)
                ts2020_stat_work(&priv->stat_work.work);

        if (c->strength.stat[0].scale == FE_SCALE_NOT_AVAILABLE) {
                *_signal_strength = 0;
                return 0;
        }

        gain = c->strength.stat[0].svalue;

        /* Calculate the signal strength based on the total gain of the tuner */
        if (gain < -85000)
                /* 0%: no signal or weak signal */
                strength = 0;
        else if (gain < -65000)
                /* 0% - 60%: weak signal */
                strength = 0 + div64_s64((85000 + gain) * 3, 1000);
        else if (gain < -45000)
                /* 60% - 90%: normal signal */
                strength = 60 + div64_s64((65000 + gain) * 3, 2000);
        else
                /* 90% - 99%: strong signal */
                strength = 90 + div64_s64((45000 + gain), 5000);

        *_signal_strength = strength * 65535 / 100;
        return 0;
}

static const struct dvb_tuner_ops ts2020_tuner_ops = {
        .info = {
                .name = "TS2020",
                .frequency_min = 950000,
                .frequency_max = 2150000
        },
        .init = ts2020_init,
        .release = ts2020_release,
        .sleep = ts2020_sleep,
        .set_params = ts2020_set_params,
        .get_frequency = ts2020_get_frequency,
        .get_if_frequency = ts2020_get_if_frequency,
        .get_rf_strength = ts2020_read_signal_strength,
};

struct dvb_frontend *ts2020_attach(struct dvb_frontend *fe,
                                        const struct ts2020_config *config,
                                        struct i2c_adapter *i2c)
{
        struct i2c_client *client;
        struct i2c_board_info board_info;

        /* This is only used by ts2020_probe() so can be on the stack */
        struct ts2020_config pdata;

        memcpy(&pdata, config, sizeof(pdata));
        pdata.fe = fe;
        pdata.attach_in_use = true;

        memset(&board_info, 0, sizeof(board_info));
        strlcpy(board_info.type, "ts2020", I2C_NAME_SIZE);
        board_info.addr = config->tuner_address;
        board_info.platform_data = &pdata;
        client = i2c_new_device(i2c, &board_info);
        if (!client || !client->dev.driver)
                return NULL;

        return fe;
}
EXPORT_SYMBOL(ts2020_attach);

/*
 * We implement own regmap locking due to legacy DVB attach which uses frontend
 * gate control callback to control I2C bus access. We can open / close gate and
 * serialize whole open / I2C-operation / close sequence at the same.
 */
static void ts2020_regmap_lock(void *__dev)
{
        struct ts2020_priv *dev = __dev;

        mutex_lock(&dev->regmap_mutex);
        if (dev->fe->ops.i2c_gate_ctrl)
                dev->fe->ops.i2c_gate_ctrl(dev->fe, 1);
}

static void ts2020_regmap_unlock(void *__dev)
{
        struct ts2020_priv *dev = __dev;

        if (dev->fe->ops.i2c_gate_ctrl)
                dev->fe->ops.i2c_gate_ctrl(dev->fe, 0);
        mutex_unlock(&dev->regmap_mutex);
}

static int ts2020_probe(struct i2c_client *client,
                const struct i2c_device_id *id)
{
        struct ts2020_config *pdata = client->dev.platform_data;
        struct dvb_frontend *fe = pdata->fe;
        struct ts2020_priv *dev;
        int ret;
        u8 u8tmp;
        unsigned int utmp;
        char *chip_str;

        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
        if (!dev) {
                ret = -ENOMEM;
                goto err;
        }

        /* create regmap */
        mutex_init(&dev->regmap_mutex);
        dev->regmap_config.reg_bits = 8,
        dev->regmap_config.val_bits = 8,
        dev->regmap_config.lock = ts2020_regmap_lock,
        dev->regmap_config.unlock = ts2020_regmap_unlock,
        dev->regmap_config.lock_arg = dev,
        dev->regmap = regmap_init_i2c(client, &dev->regmap_config);
        if (IS_ERR(dev->regmap)) {
                ret = PTR_ERR(dev->regmap);
                goto err_kfree;
        }

        dev->i2c = client->adapter;
        dev->i2c_address = client->addr;
        dev->loop_through = pdata->loop_through;
        dev->clk_out = pdata->clk_out;
        dev->clk_out_div = pdata->clk_out_div;
        dev->dont_poll = pdata->dont_poll;
        dev->frequency_div = pdata->frequency_div;
        dev->fe = fe;
        dev->get_agc_pwm = pdata->get_agc_pwm;
        fe->tuner_priv = dev;
        dev->client = client;
        INIT_DELAYED_WORK(&dev->stat_work, ts2020_stat_work);

        /* check if the tuner is there */
        ret = regmap_read(dev->regmap, 0x00, &utmp);
        if (ret)
                goto err_regmap_exit;

        if ((utmp & 0x03) == 0x00) {
                ret = regmap_write(dev->regmap, 0x00, 0x01);
                if (ret)
                        goto err_regmap_exit;

                usleep_range(2000, 50000);
        }

        ret = regmap_write(dev->regmap, 0x00, 0x03);
        if (ret)
                goto err_regmap_exit;

        usleep_range(2000, 50000);

        ret = regmap_read(dev->regmap, 0x00, &utmp);
        if (ret)
                goto err_regmap_exit;

        dev_dbg(&client->dev, "chip_id=%02x\n", utmp);

        switch (utmp) {
        case 0x01:
        case 0x41:
        case 0x81:
                dev->tuner = TS2020_M88TS2020;
                chip_str = "TS2020";
                if (!dev->frequency_div)
                        dev->frequency_div = 1060000;
                break;
        case 0xc3:
        case 0x83:
                dev->tuner = TS2020_M88TS2022;
                chip_str = "TS2022";
                if (!dev->frequency_div)
                        dev->frequency_div = 1103000;
                break;
        default:
                ret = -ENODEV;
                goto err_regmap_exit;
        }

        if (dev->tuner == TS2020_M88TS2022) {
                switch (dev->clk_out) {
                case TS2020_CLK_OUT_DISABLED:
                        u8tmp = 0x60;
                        break;
                case TS2020_CLK_OUT_ENABLED:
                        u8tmp = 0x70;
                        ret = regmap_write(dev->regmap, 0x05, dev->clk_out_div);
                        if (ret)
                                goto err_regmap_exit;
                        break;
                case TS2020_CLK_OUT_ENABLED_XTALOUT:
                        u8tmp = 0x6c;
                        break;
                default:
                        ret = -EINVAL;
                        goto err_regmap_exit;
                }

                ret = regmap_write(dev->regmap, 0x42, u8tmp);
                if (ret)
                        goto err_regmap_exit;

                if (dev->loop_through)
                        u8tmp = 0xec;
                else
                        u8tmp = 0x6c;

                ret = regmap_write(dev->regmap, 0x62, u8tmp);
                if (ret)
                        goto err_regmap_exit;
        }

        /* sleep */
        ret = regmap_write(dev->regmap, 0x00, 0x00);
        if (ret)
                goto err_regmap_exit;

        dev_info(&client->dev,
                 "Montage Technology %s successfully identified\n", chip_str);

        memcpy(&fe->ops.tuner_ops, &ts2020_tuner_ops,
                        sizeof(struct dvb_tuner_ops));
        if (!pdata->attach_in_use)
                fe->ops.tuner_ops.release = NULL;

        i2c_set_clientdata(client, dev);
        return 0;
err_regmap_exit:
        regmap_exit(dev->regmap);
err_kfree:
        kfree(dev);
err:
        dev_dbg(&client->dev, "failed=%d\n", ret);
        return ret;
}

static int ts2020_remove(struct i2c_client *client)
{
        struct ts2020_priv *dev = i2c_get_clientdata(client);

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

        /* stop statistics polling */
        if (!dev->dont_poll)
                cancel_delayed_work_sync(&dev->stat_work);

        regmap_exit(dev->regmap);
        kfree(dev);
        return 0;
}

static const struct i2c_device_id ts2020_id_table[] = {
        {"ts2020", 0},
        {"ts2022", 0},
        {}
};
MODULE_DEVICE_TABLE(i2c, ts2020_id_table);

static struct i2c_driver ts2020_driver = {
        .driver = {
                .name   = "ts2020",
        },
        .probe          = ts2020_probe,
        .remove         = ts2020_remove,
        .id_table       = ts2020_id_table,
};

module_i2c_driver(ts2020_driver);

MODULE_AUTHOR("Konstantin Dimitrov <kosio.dimitrov@gmail.com>");
MODULE_DESCRIPTION("Montage Technology TS2020 - Silicon tuner driver module");
MODULE_LICENSE("GPL");