// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Realtek RTL2830 DVB-T demodulator driver
 *
 * Copyright (C) 2011 Antti Palosaari <crope@iki.fi>
 */

#include "rtl2830_priv.h"

/* Our regmap is bypassing I2C adapter lock, thus we do it! */
static int rtl2830_bulk_write(struct i2c_client *client, unsigned int reg,
                              const void *val, size_t val_count)
{
        struct rtl2830_dev *dev = i2c_get_clientdata(client);
        int ret;

        i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
        ret = regmap_bulk_write(dev->regmap, reg, val, val_count);
        i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
        return ret;
}

static int rtl2830_update_bits(struct i2c_client *client, unsigned int reg,
                               unsigned int mask, unsigned int val)
{
        struct rtl2830_dev *dev = i2c_get_clientdata(client);
        int ret;

        i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
        ret = regmap_update_bits(dev->regmap, reg, mask, val);
        i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
        return ret;
}

static int rtl2830_bulk_read(struct i2c_client *client, unsigned int reg,
                             void *val, size_t val_count)
{
        struct rtl2830_dev *dev = i2c_get_clientdata(client);
        int ret;

        i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
        ret = regmap_bulk_read(dev->regmap, reg, val, val_count);
        i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
        return ret;
}

static int rtl2830_init(struct dvb_frontend *fe)
{
        struct i2c_client *client = fe->demodulator_priv;
        struct rtl2830_dev *dev = i2c_get_clientdata(client);
        struct dtv_frontend_properties *c = &dev->fe.dtv_property_cache;
        int ret, i;
        struct rtl2830_reg_val_mask tab[] = {
                {0x00d, 0x01, 0x03},
                {0x00d, 0x10, 0x10},
                {0x104, 0x00, 0x1e},
                {0x105, 0x80, 0x80},
                {0x110, 0x02, 0x03},
                {0x110, 0x08, 0x0c},
                {0x17b, 0x00, 0x40},
                {0x17d, 0x05, 0x0f},
                {0x17d, 0x50, 0xf0},
                {0x18c, 0x08, 0x0f},
                {0x18d, 0x00, 0xc0},
                {0x188, 0x05, 0x0f},
                {0x189, 0x00, 0xfc},
                {0x2d5, 0x02, 0x02},
                {0x2f1, 0x02, 0x06},
                {0x2f1, 0x20, 0xf8},
                {0x16d, 0x00, 0x01},
                {0x1a6, 0x00, 0x80},
                {0x106, dev->pdata->vtop, 0x3f},
                {0x107, dev->pdata->krf, 0x3f},
                {0x112, 0x28, 0xff},
                {0x103, dev->pdata->agc_targ_val, 0xff},
                {0x00a, 0x02, 0x07},
                {0x140, 0x0c, 0x3c},
                {0x140, 0x40, 0xc0},
                {0x15b, 0x05, 0x07},
                {0x15b, 0x28, 0x38},
                {0x15c, 0x05, 0x07},
                {0x15c, 0x28, 0x38},
                {0x115, dev->pdata->spec_inv, 0x01},
                {0x16f, 0x01, 0x07},
                {0x170, 0x18, 0x38},
                {0x172, 0x0f, 0x0f},
                {0x173, 0x08, 0x38},
                {0x175, 0x01, 0x07},
                {0x176, 0x00, 0xc0},
        };

        for (i = 0; i < ARRAY_SIZE(tab); i++) {
                ret = rtl2830_update_bits(client, tab[i].reg, tab[i].mask,
                                          tab[i].val);
                if (ret)
                        goto err;
        }

        ret = rtl2830_bulk_write(client, 0x18f, "\x28\x00", 2);
        if (ret)
                goto err;

        ret = rtl2830_bulk_write(client, 0x195,
                                 "\x04\x06\x0a\x12\x0a\x12\x1e\x28", 8);
        if (ret)
                goto err;

        /* TODO: spec init */

        /* soft reset */
        ret = rtl2830_update_bits(client, 0x101, 0x04, 0x04);
        if (ret)
                goto err;

        ret = rtl2830_update_bits(client, 0x101, 0x04, 0x00);
        if (ret)
                goto err;

        /* init stats here in order signal app which stats are supported */
        c->strength.len = 1;
        c->strength.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        c->cnr.len = 1;
        c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        c->post_bit_error.len = 1;
        c->post_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        c->post_bit_count.len = 1;
        c->post_bit_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;

        dev->sleeping = false;

        return ret;
err:
        dev_dbg(&client->dev, "failed=%d\n", ret);
        return ret;
}

static int rtl2830_sleep(struct dvb_frontend *fe)
{
        struct i2c_client *client = fe->demodulator_priv;
        struct rtl2830_dev *dev = i2c_get_clientdata(client);

        dev->sleeping = true;
        dev->fe_status = 0;

        return 0;
}

static int rtl2830_get_tune_settings(struct dvb_frontend *fe,
                                     struct dvb_frontend_tune_settings *s)
{
        s->min_delay_ms = 500;
        s->step_size = fe->ops.info.frequency_stepsize_hz * 2;
        s->max_drift = (fe->ops.info.frequency_stepsize_hz * 2) + 1;

        return 0;
}

static int rtl2830_set_frontend(struct dvb_frontend *fe)
{
        struct i2c_client *client = fe->demodulator_priv;
        struct rtl2830_dev *dev = i2c_get_clientdata(client);
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        int ret, i;
        u64 num;
        u8 buf[3], u8tmp;
        u32 if_ctl, if_frequency;
        static const u8 bw_params1[3][34] = {
                {
                0x1f, 0xf0, 0x1f, 0xf0, 0x1f, 0xfa, 0x00, 0x17, 0x00, 0x41,
                0x00, 0x64, 0x00, 0x67, 0x00, 0x38, 0x1f, 0xde, 0x1f, 0x7a,
                0x1f, 0x47, 0x1f, 0x7c, 0x00, 0x30, 0x01, 0x4b, 0x02, 0x82,
                0x03, 0x73, 0x03, 0xcf, /* 6 MHz */
                }, {
                0x1f, 0xfa, 0x1f, 0xda, 0x1f, 0xc1, 0x1f, 0xb3, 0x1f, 0xca,
                0x00, 0x07, 0x00, 0x4d, 0x00, 0x6d, 0x00, 0x40, 0x1f, 0xca,
                0x1f, 0x4d, 0x1f, 0x2a, 0x1f, 0xb2, 0x00, 0xec, 0x02, 0x7e,
                0x03, 0xd0, 0x04, 0x53, /* 7 MHz */
                }, {
                0x00, 0x10, 0x00, 0x0e, 0x1f, 0xf7, 0x1f, 0xc9, 0x1f, 0xa0,
                0x1f, 0xa6, 0x1f, 0xec, 0x00, 0x4e, 0x00, 0x7d, 0x00, 0x3a,
                0x1f, 0x98, 0x1f, 0x10, 0x1f, 0x40, 0x00, 0x75, 0x02, 0x5f,
                0x04, 0x24, 0x04, 0xdb, /* 8 MHz */
                },
        };
        static const u8 bw_params2[3][6] = {
                {0xc3, 0x0c, 0x44, 0x33, 0x33, 0x30}, /* 6 MHz */
                {0xb8, 0xe3, 0x93, 0x99, 0x99, 0x98}, /* 7 MHz */
                {0xae, 0xba, 0xf3, 0x26, 0x66, 0x64}, /* 8 MHz */
        };

        dev_dbg(&client->dev, "frequency=%u bandwidth_hz=%u inversion=%u\n",
                c->frequency, c->bandwidth_hz, c->inversion);

        /* program tuner */
        if (fe->ops.tuner_ops.set_params)
                fe->ops.tuner_ops.set_params(fe);

        switch (c->bandwidth_hz) {
        case 6000000:
                i = 0;
                break;
        case 7000000:
                i = 1;
                break;
        case 8000000:
                i = 2;
                break;
        default:
                dev_err(&client->dev, "invalid bandwidth_hz %u\n",
                        c->bandwidth_hz);
                return -EINVAL;
        }

        ret = rtl2830_update_bits(client, 0x008, 0x06, i << 1);
        if (ret)
                goto err;

        /* program if frequency */
        if (fe->ops.tuner_ops.get_if_frequency)
                ret = fe->ops.tuner_ops.get_if_frequency(fe, &if_frequency);
        else
                ret = -EINVAL;
        if (ret)
                goto err;

        num = if_frequency % dev->pdata->clk;
        num *= 0x400000;
        num = div_u64(num, dev->pdata->clk);
        num = -num;
        if_ctl = num & 0x3fffff;
        dev_dbg(&client->dev, "if_frequency=%d if_ctl=%08x\n",
                if_frequency, if_ctl);

        buf[0] = (if_ctl >> 16) & 0x3f;
        buf[1] = (if_ctl >>  8) & 0xff;
        buf[2] = (if_ctl >>  0) & 0xff;

        ret = rtl2830_bulk_read(client, 0x119, &u8tmp, 1);
        if (ret)
                goto err;

        buf[0] |= u8tmp & 0xc0;  /* [7:6] */

        ret = rtl2830_bulk_write(client, 0x119, buf, 3);
        if (ret)
                goto err;

        /* 1/2 split I2C write */
        ret = rtl2830_bulk_write(client, 0x11c, &bw_params1[i][0], 17);
        if (ret)
                goto err;

        /* 2/2 split I2C write */
        ret = rtl2830_bulk_write(client, 0x12d, &bw_params1[i][17], 17);
        if (ret)
                goto err;

        ret = rtl2830_bulk_write(client, 0x19d, bw_params2[i], 6);
        if (ret)
                goto err;

        return ret;
err:
        dev_dbg(&client->dev, "failed=%d\n", ret);
        return ret;
}

static int rtl2830_get_frontend(struct dvb_frontend *fe,
                                struct dtv_frontend_properties *c)
{
        struct i2c_client *client = fe->demodulator_priv;
        struct rtl2830_dev *dev = i2c_get_clientdata(client);
        int ret;
        u8 buf[3];

        if (dev->sleeping)
                return 0;

        ret = rtl2830_bulk_read(client, 0x33c, buf, 2);
        if (ret)
                goto err;

        ret = rtl2830_bulk_read(client, 0x351, &buf[2], 1);
        if (ret)
                goto err;

        dev_dbg(&client->dev, "TPS=%*ph\n", 3, buf);

        switch ((buf[0] >> 2) & 3) {
        case 0:
                c->modulation = QPSK;
                break;
        case 1:
                c->modulation = QAM_16;
                break;
        case 2:
                c->modulation = QAM_64;
                break;
        }

        switch ((buf[2] >> 2) & 1) {
        case 0:
                c->transmission_mode = TRANSMISSION_MODE_2K;
                break;
        case 1:
                c->transmission_mode = TRANSMISSION_MODE_8K;
        }

        switch ((buf[2] >> 0) & 3) {
        case 0:
                c->guard_interval = GUARD_INTERVAL_1_32;
                break;
        case 1:
                c->guard_interval = GUARD_INTERVAL_1_16;
                break;
        case 2:
                c->guard_interval = GUARD_INTERVAL_1_8;
                break;
        case 3:
                c->guard_interval = GUARD_INTERVAL_1_4;
                break;
        }

        switch ((buf[0] >> 4) & 7) {
        case 0:
                c->hierarchy = HIERARCHY_NONE;
                break;
        case 1:
                c->hierarchy = HIERARCHY_1;
                break;
        case 2:
                c->hierarchy = HIERARCHY_2;
                break;
        case 3:
                c->hierarchy = HIERARCHY_4;
                break;
        }

        switch ((buf[1] >> 3) & 7) {
        case 0:
                c->code_rate_HP = FEC_1_2;
                break;
        case 1:
                c->code_rate_HP = FEC_2_3;
                break;
        case 2:
                c->code_rate_HP = FEC_3_4;
                break;
        case 3:
                c->code_rate_HP = FEC_5_6;
                break;
        case 4:
                c->code_rate_HP = FEC_7_8;
                break;
        }

        switch ((buf[1] >> 0) & 7) {
        case 0:
                c->code_rate_LP = FEC_1_2;
                break;
        case 1:
                c->code_rate_LP = FEC_2_3;
                break;
        case 2:
                c->code_rate_LP = FEC_3_4;
                break;
        case 3:
                c->code_rate_LP = FEC_5_6;
                break;
        case 4:
                c->code_rate_LP = FEC_7_8;
                break;
        }

        return 0;
err:
        dev_dbg(&client->dev, "failed=%d\n", ret);
        return ret;
}

static int rtl2830_read_status(struct dvb_frontend *fe, enum fe_status *status)
{
        struct i2c_client *client = fe->demodulator_priv;
        struct rtl2830_dev *dev = i2c_get_clientdata(client);
        struct dtv_frontend_properties *c = &dev->fe.dtv_property_cache;
        int ret, stmp;
        unsigned int utmp;
        u8 u8tmp, buf[2];

        *status = 0;

        if (dev->sleeping)
                return 0;

        ret = rtl2830_bulk_read(client, 0x351, &u8tmp, 1);
        if (ret)
                goto err;

        u8tmp = (u8tmp >> 3) & 0x0f; /* [6:3] */
        if (u8tmp == 11) {
                *status |= FE_HAS_SIGNAL | FE_HAS_CARRIER |
                        FE_HAS_VITERBI | FE_HAS_SYNC | FE_HAS_LOCK;
        } else if (u8tmp == 10) {
                *status |= FE_HAS_SIGNAL | FE_HAS_CARRIER |
                        FE_HAS_VITERBI;
        }

        dev->fe_status = *status;

        /* Signal strength */
        if (dev->fe_status & FE_HAS_SIGNAL) {
                /* Read IF AGC */
                ret = rtl2830_bulk_read(client, 0x359, buf, 2);
                if (ret)
                        goto err;

                stmp = buf[0] << 8 | buf[1] << 0;
                stmp = sign_extend32(stmp, 13);
                utmp = clamp_val(-4 * stmp + 32767, 0x0000, 0xffff);

                dev_dbg(&client->dev, "IF AGC=%d\n", stmp);

                c->strength.stat[0].scale = FE_SCALE_RELATIVE;
                c->strength.stat[0].uvalue = utmp;
        } else {
                c->strength.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        }

        /* CNR */
        if (dev->fe_status & FE_HAS_VITERBI) {
                unsigned int hierarchy, constellation;
                #define CONSTELLATION_NUM 3
                #define HIERARCHY_NUM 4
                static const u32 constant[CONSTELLATION_NUM][HIERARCHY_NUM] = {
                        {70705899, 70705899, 70705899, 70705899},
                        {82433173, 82433173, 87483115, 94445660},
                        {92888734, 92888734, 95487525, 99770748},
                };

                ret = rtl2830_bulk_read(client, 0x33c, &u8tmp, 1);
                if (ret)
                        goto err;

                constellation = (u8tmp >> 2) & 0x03; /* [3:2] */
                if (constellation > CONSTELLATION_NUM - 1)
                        goto err;

                hierarchy = (u8tmp >> 4) & 0x07; /* [6:4] */
                if (hierarchy > HIERARCHY_NUM - 1)
                        goto err;

                ret = rtl2830_bulk_read(client, 0x40c, buf, 2);
                if (ret)
                        goto err;

                utmp = buf[0] << 8 | buf[1] << 0;
                if (utmp)
                        stmp = (constant[constellation][hierarchy] -
                               intlog10(utmp)) / ((1 << 24) / 10000);
                else
                        stmp = 0;

                dev_dbg(&client->dev, "CNR raw=%u\n", utmp);

                c->cnr.stat[0].scale = FE_SCALE_DECIBEL;
                c->cnr.stat[0].svalue = stmp;
        } else {
                c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        }

        /* BER */
        if (dev->fe_status & FE_HAS_LOCK) {
                ret = rtl2830_bulk_read(client, 0x34e, buf, 2);
                if (ret)
                        goto err;

                utmp = buf[0] << 8 | buf[1] << 0;
                dev->post_bit_error += utmp;
                dev->post_bit_count += 1000000;

                dev_dbg(&client->dev, "BER errors=%u total=1000000\n", utmp);

                c->post_bit_error.stat[0].scale = FE_SCALE_COUNTER;
                c->post_bit_error.stat[0].uvalue = dev->post_bit_error;
                c->post_bit_count.stat[0].scale = FE_SCALE_COUNTER;
                c->post_bit_count.stat[0].uvalue = dev->post_bit_count;
        } else {
                c->post_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
                c->post_bit_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        }


        return ret;
err:
        dev_dbg(&client->dev, "failed=%d\n", ret);
        return ret;
}

static int rtl2830_read_snr(struct dvb_frontend *fe, u16 *snr)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;

        if (c->cnr.stat[0].scale == FE_SCALE_DECIBEL)
                *snr = div_s64(c->cnr.stat[0].svalue, 100);
        else
                *snr = 0;

        return 0;
}

static int rtl2830_read_ber(struct dvb_frontend *fe, u32 *ber)
{
        struct i2c_client *client = fe->demodulator_priv;
        struct rtl2830_dev *dev = i2c_get_clientdata(client);

        *ber = (dev->post_bit_error - dev->post_bit_error_prev);
        dev->post_bit_error_prev = dev->post_bit_error;

        return 0;
}

static int rtl2830_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
{
        *ucblocks = 0;

        return 0;
}

static int rtl2830_read_signal_strength(struct dvb_frontend *fe, u16 *strength)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;

        if (c->strength.stat[0].scale == FE_SCALE_RELATIVE)
                *strength = c->strength.stat[0].uvalue;
        else
                *strength = 0;

        return 0;
}

static const struct dvb_frontend_ops rtl2830_ops = {
        .delsys = {SYS_DVBT},
        .info = {
                .name = "Realtek RTL2830 (DVB-T)",
                .caps = FE_CAN_FEC_1_2 |
                        FE_CAN_FEC_2_3 |
                        FE_CAN_FEC_3_4 |
                        FE_CAN_FEC_5_6 |
                        FE_CAN_FEC_7_8 |
                        FE_CAN_FEC_AUTO |
                        FE_CAN_QPSK |
                        FE_CAN_QAM_16 |
                        FE_CAN_QAM_64 |
                        FE_CAN_QAM_AUTO |
                        FE_CAN_TRANSMISSION_MODE_AUTO |
                        FE_CAN_GUARD_INTERVAL_AUTO |
                        FE_CAN_HIERARCHY_AUTO |
                        FE_CAN_RECOVER |
                        FE_CAN_MUTE_TS
        },

        .init = rtl2830_init,
        .sleep = rtl2830_sleep,

        .get_tune_settings = rtl2830_get_tune_settings,

        .set_frontend = rtl2830_set_frontend,
        .get_frontend = rtl2830_get_frontend,

        .read_status = rtl2830_read_status,
        .read_snr = rtl2830_read_snr,
        .read_ber = rtl2830_read_ber,
        .read_ucblocks = rtl2830_read_ucblocks,
        .read_signal_strength = rtl2830_read_signal_strength,
};

static int rtl2830_pid_filter_ctrl(struct dvb_frontend *fe, int onoff)
{
        struct i2c_client *client = fe->demodulator_priv;
        int ret;
        u8 u8tmp;

        dev_dbg(&client->dev, "onoff=%d\n", onoff);

        /* enable / disable PID filter */
        if (onoff)
                u8tmp = 0x80;
        else
                u8tmp = 0x00;

        ret = rtl2830_update_bits(client, 0x061, 0x80, u8tmp);
        if (ret)
                goto err;

        return 0;
err:
        dev_dbg(&client->dev, "failed=%d\n", ret);
        return ret;
}

static int rtl2830_pid_filter(struct dvb_frontend *fe, u8 index, u16 pid, int onoff)
{
        struct i2c_client *client = fe->demodulator_priv;
        struct rtl2830_dev *dev = i2c_get_clientdata(client);
        int ret;
        u8 buf[4];

        dev_dbg(&client->dev, "index=%d pid=%04x onoff=%d\n",
                index, pid, onoff);

        /* skip invalid PIDs (0x2000) */
        if (pid > 0x1fff || index >= 32)
                return 0;

        if (onoff)
                set_bit(index, &dev->filters);
        else
                clear_bit(index, &dev->filters);

        /* enable / disable PIDs */
        buf[0] = (dev->filters >>  0) & 0xff;
        buf[1] = (dev->filters >>  8) & 0xff;
        buf[2] = (dev->filters >> 16) & 0xff;
        buf[3] = (dev->filters >> 24) & 0xff;
        ret = rtl2830_bulk_write(client, 0x062, buf, 4);
        if (ret)
                goto err;

        /* add PID */
        buf[0] = (pid >> 8) & 0xff;
        buf[1] = (pid >> 0) & 0xff;
        ret = rtl2830_bulk_write(client, 0x066 + 2 * index, buf, 2);
        if (ret)
                goto err;

        return 0;
err:
        dev_dbg(&client->dev, "failed=%d\n", ret);
        return ret;
}

/*
 * I2C gate/mux/repeater logic
 * We must use unlocked __i2c_transfer() here (through regmap) because of I2C
 * adapter lock is already taken by tuner driver.
 * Gate is closed automatically after single I2C transfer.
 */
static int rtl2830_select(struct i2c_mux_core *muxc, u32 chan_id)
{
        struct i2c_client *client = i2c_mux_priv(muxc);
        struct rtl2830_dev *dev = i2c_get_clientdata(client);
        int ret;

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

        /* open I2C repeater for 1 transfer, closes automatically */
        /* XXX: regmap_update_bits() does not lock I2C adapter */
        ret = regmap_update_bits(dev->regmap, 0x101, 0x08, 0x08);
        if (ret)
                goto err;

        return 0;
err:
        dev_dbg(&client->dev, "failed=%d\n", ret);
        return ret;
}

static struct dvb_frontend *rtl2830_get_dvb_frontend(struct i2c_client *client)
{
        struct rtl2830_dev *dev = i2c_get_clientdata(client);

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

        return &dev->fe;
}

static struct i2c_adapter *rtl2830_get_i2c_adapter(struct i2c_client *client)
{
        struct rtl2830_dev *dev = i2c_get_clientdata(client);

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

        return dev->muxc->adapter[0];
}

/*
 * We implement own I2C access routines for regmap in order to get manual access
 * to I2C adapter lock, which is needed for I2C mux adapter.
 */
static int rtl2830_regmap_read(void *context, const void *reg_buf,
                               size_t reg_size, void *val_buf, size_t val_size)
{
        struct i2c_client *client = context;
        int ret;
        struct i2c_msg msg[2] = {
                {
                        .addr = client->addr,
                        .flags = 0,
                        .len = reg_size,
                        .buf = (u8 *)reg_buf,
                }, {
                        .addr = client->addr,
                        .flags = I2C_M_RD,
                        .len = val_size,
                        .buf = val_buf,
                }
        };

        ret = __i2c_transfer(client->adapter, msg, 2);
        if (ret != 2) {
                dev_warn(&client->dev, "i2c reg read failed %d\n", ret);
                if (ret >= 0)
                        ret = -EREMOTEIO;
                return ret;
        }
        return 0;
}

static int rtl2830_regmap_write(void *context, const void *data, size_t count)
{
        struct i2c_client *client = context;
        int ret;
        struct i2c_msg msg[1] = {
                {
                        .addr = client->addr,
                        .flags = 0,
                        .len = count,
                        .buf = (u8 *)data,
                }
        };

        ret = __i2c_transfer(client->adapter, msg, 1);
        if (ret != 1) {
                dev_warn(&client->dev, "i2c reg write failed %d\n", ret);
                if (ret >= 0)
                        ret = -EREMOTEIO;
                return ret;
        }
        return 0;
}

static int rtl2830_regmap_gather_write(void *context, const void *reg,
                                       size_t reg_len, const void *val,
                                       size_t val_len)
{
        struct i2c_client *client = context;
        int ret;
        u8 buf[256];
        struct i2c_msg msg[1] = {
                {
                        .addr = client->addr,
                        .flags = 0,
                        .len = 1 + val_len,
                        .buf = buf,
                }
        };

        buf[0] = *(u8 const *)reg;
        memcpy(&buf[1], val, val_len);

        ret = __i2c_transfer(client->adapter, msg, 1);
        if (ret != 1) {
                dev_warn(&client->dev, "i2c reg write failed %d\n", ret);
                if (ret >= 0)
                        ret = -EREMOTEIO;
                return ret;
        }
        return 0;
}

static int rtl2830_probe(struct i2c_client *client)
{
        struct rtl2830_platform_data *pdata = client->dev.platform_data;
        struct rtl2830_dev *dev;
        int ret;
        u8 u8tmp;
        static const struct regmap_bus regmap_bus = {
                .read = rtl2830_regmap_read,
                .write = rtl2830_regmap_write,
                .gather_write = rtl2830_regmap_gather_write,
                .val_format_endian_default = REGMAP_ENDIAN_NATIVE,
        };
        static const struct regmap_range_cfg regmap_range_cfg[] = {
                {
                        .selector_reg     = 0x00,
                        .selector_mask    = 0xff,
                        .selector_shift   = 0,
                        .window_start     = 0,
                        .window_len       = 0x100,
                        .range_min        = 0 * 0x100,
                        .range_max        = 5 * 0x100,
                },
        };
        static const struct regmap_config regmap_config = {
                .reg_bits    =  8,
                .val_bits    =  8,
                .max_register = 5 * 0x100,
                .ranges = regmap_range_cfg,
                .num_ranges = ARRAY_SIZE(regmap_range_cfg),
        };

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

        if (pdata == NULL) {
                ret = -EINVAL;
                goto err;
        }

        /* allocate memory for the internal state */
        dev = kzalloc_obj(*dev);
        if (dev == NULL) {
                ret = -ENOMEM;
                goto err;
        }

        /* setup the state */
        i2c_set_clientdata(client, dev);
        dev->client = client;
        dev->pdata = client->dev.platform_data;
        dev->sleeping = true;
        dev->regmap = regmap_init(&client->dev, &regmap_bus, client,
                                  &regmap_config);
        if (IS_ERR(dev->regmap)) {
                ret = PTR_ERR(dev->regmap);
                goto err_kfree;
        }

        /* check if the demod is there */
        ret = rtl2830_bulk_read(client, 0x000, &u8tmp, 1);
        if (ret)
                goto err_regmap_exit;

        /* create muxed i2c adapter for tuner */
        dev->muxc = i2c_mux_alloc(client->adapter, &client->dev, 1, 0, 0,
                                  rtl2830_select, NULL);
        if (!dev->muxc) {
                ret = -ENOMEM;
                goto err_regmap_exit;
        }
        dev->muxc->priv = client;
        ret = i2c_mux_add_adapter(dev->muxc, 0, 0);
        if (ret)
                goto err_regmap_exit;

        /* create dvb frontend */
        memcpy(&dev->fe.ops, &rtl2830_ops, sizeof(dev->fe.ops));
        dev->fe.demodulator_priv = client;

        /* setup callbacks */
        pdata->get_dvb_frontend = rtl2830_get_dvb_frontend;
        pdata->get_i2c_adapter = rtl2830_get_i2c_adapter;
        pdata->pid_filter = rtl2830_pid_filter;
        pdata->pid_filter_ctrl = rtl2830_pid_filter_ctrl;

        dev_info(&client->dev, "Realtek RTL2830 successfully attached\n");

        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 void rtl2830_remove(struct i2c_client *client)
{
        struct rtl2830_dev *dev = i2c_get_clientdata(client);

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

        i2c_mux_del_adapters(dev->muxc);
        regmap_exit(dev->regmap);
        kfree(dev);
}

static const struct i2c_device_id rtl2830_id_table[] = {
        { "rtl2830" },
        {}
};
MODULE_DEVICE_TABLE(i2c, rtl2830_id_table);

static struct i2c_driver rtl2830_driver = {
        .driver = {
                .name                   = "rtl2830",
                .suppress_bind_attrs    = true,
        },
        .probe          = rtl2830_probe,
        .remove         = rtl2830_remove,
        .id_table       = rtl2830_id_table,
};

module_i2c_driver(rtl2830_driver);

MODULE_AUTHOR("Antti Palosaari <crope@iki.fi>");
MODULE_DESCRIPTION("Realtek RTL2830 DVB-T demodulator driver");
MODULE_LICENSE("GPL");