// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * E3C EC100 demodulator driver
 *
 * Copyright (C) 2009 Antti Palosaari <crope@iki.fi>
 */

#include <media/dvb_frontend.h>
#include "ec100.h"

struct ec100_state {
        struct i2c_adapter *i2c;
        struct dvb_frontend frontend;
        struct ec100_config config;

        u16 ber;
};

/* write single register */
static int ec100_write_reg(struct ec100_state *state, u8 reg, u8 val)
{
        int ret;
        u8 buf[2] = {reg, val};
        struct i2c_msg msg[1] = {
                {
                        .addr = state->config.demod_address,
                        .flags = 0,
                        .len = sizeof(buf),
                        .buf = buf,
                }
        };

        ret = i2c_transfer(state->i2c, msg, 1);
        if (ret == 1) {
                ret = 0;
        } else {
                dev_warn(&state->i2c->dev, "%s: i2c wr failed=%d reg=%02x\n",
                                KBUILD_MODNAME, ret, reg);
                ret = -EREMOTEIO;
        }

        return ret;
}

/* read single register */
static int ec100_read_reg(struct ec100_state *state, u8 reg, u8 *val)
{
        int ret;
        struct i2c_msg msg[2] = {
                {
                        .addr = state->config.demod_address,
                        .flags = 0,
                        .len = 1,
                        .buf = &reg
                }, {
                        .addr = state->config.demod_address,
                        .flags = I2C_M_RD,
                        .len = 1,
                        .buf = val
                }
        };

        ret = i2c_transfer(state->i2c, msg, 2);
        if (ret == 2) {
                ret = 0;
        } else {
                dev_warn(&state->i2c->dev, "%s: i2c rd failed=%d reg=%02x\n",
                                KBUILD_MODNAME, ret, reg);
                ret = -EREMOTEIO;
        }

        return ret;
}

static int ec100_set_frontend(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        struct ec100_state *state = fe->demodulator_priv;
        int ret;
        u8 tmp, tmp2;

        dev_dbg(&state->i2c->dev, "%s: frequency=%d bandwidth_hz=%d\n",
                        __func__, c->frequency, c->bandwidth_hz);

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

        ret = ec100_write_reg(state, 0x04, 0x06);
        if (ret)
                goto error;
        ret = ec100_write_reg(state, 0x67, 0x58);
        if (ret)
                goto error;
        ret = ec100_write_reg(state, 0x05, 0x18);
        if (ret)
                goto error;

        /* reg/bw |   6  |   7  |   8
           -------+------+------+------
           A 0x1b | 0xa1 | 0xe7 | 0x2c
           A 0x1c | 0x55 | 0x63 | 0x72
           -------+------+------+------
           B 0x1b | 0xb7 | 0x00 | 0x49
           B 0x1c | 0x55 | 0x64 | 0x72 */

        switch (c->bandwidth_hz) {
        case 6000000:
                tmp = 0xb7;
                tmp2 = 0x55;
                break;
        case 7000000:
                tmp = 0x00;
                tmp2 = 0x64;
                break;
        case 8000000:
        default:
                tmp = 0x49;
                tmp2 = 0x72;
        }

        ret = ec100_write_reg(state, 0x1b, tmp);
        if (ret)
                goto error;
        ret = ec100_write_reg(state, 0x1c, tmp2);
        if (ret)
                goto error;

        ret = ec100_write_reg(state, 0x0c, 0xbb); /* if freq */
        if (ret)
                goto error;
        ret = ec100_write_reg(state, 0x0d, 0x31); /* if freq */
        if (ret)
                goto error;

        ret = ec100_write_reg(state, 0x08, 0x24);
        if (ret)
                goto error;

        ret = ec100_write_reg(state, 0x00, 0x00); /* go */
        if (ret)
                goto error;
        ret = ec100_write_reg(state, 0x00, 0x20); /* go */
        if (ret)
                goto error;

        return ret;
error:
        dev_dbg(&state->i2c->dev, "%s: failed=%d\n", __func__, ret);
        return ret;
}

static int ec100_get_tune_settings(struct dvb_frontend *fe,
        struct dvb_frontend_tune_settings *fesettings)
{
        fesettings->min_delay_ms = 300;
        fesettings->step_size = 0;
        fesettings->max_drift = 0;

        return 0;
}

static int ec100_read_status(struct dvb_frontend *fe, enum fe_status *status)
{
        struct ec100_state *state = fe->demodulator_priv;
        int ret;
        u8 tmp;
        *status = 0;

        ret = ec100_read_reg(state, 0x42, &tmp);
        if (ret)
                goto error;

        if (tmp & 0x80) {
                /* bit7 set - have lock */
                *status |= FE_HAS_SIGNAL | FE_HAS_CARRIER | FE_HAS_VITERBI |
                        FE_HAS_SYNC | FE_HAS_LOCK;
        } else {
                ret = ec100_read_reg(state, 0x01, &tmp);
                if (ret)
                        goto error;

                if (tmp & 0x10) {
                        /* bit4 set - have signal */
                        *status |= FE_HAS_SIGNAL;
                        if (!(tmp & 0x01)) {
                                /* bit0 clear - have ~valid signal */
                                *status |= FE_HAS_CARRIER |  FE_HAS_VITERBI;
                        }
                }
        }

        return ret;
error:
        dev_dbg(&state->i2c->dev, "%s: failed=%d\n", __func__, ret);
        return ret;
}

static int ec100_read_ber(struct dvb_frontend *fe, u32 *ber)
{
        struct ec100_state *state = fe->demodulator_priv;
        int ret;
        u8 tmp, tmp2;
        u16 ber2;

        *ber = 0;

        ret = ec100_read_reg(state, 0x65, &tmp);
        if (ret)
                goto error;
        ret = ec100_read_reg(state, 0x66, &tmp2);
        if (ret)
                goto error;

        ber2 = (tmp2 << 8) | tmp;

        /* if counter overflow or clear */
        if (ber2 < state->ber)
                *ber = ber2;
        else
                *ber = ber2 - state->ber;

        state->ber = ber2;

        return ret;
error:
        dev_dbg(&state->i2c->dev, "%s: failed=%d\n", __func__, ret);
        return ret;
}

static int ec100_read_signal_strength(struct dvb_frontend *fe, u16 *strength)
{
        struct ec100_state *state = fe->demodulator_priv;
        int ret;
        u8 tmp;

        ret = ec100_read_reg(state, 0x24, &tmp);
        if (ret) {
                *strength = 0;
                goto error;
        }

        *strength = ((tmp << 8) | tmp);

        return ret;
error:
        dev_dbg(&state->i2c->dev, "%s: failed=%d\n", __func__, ret);
        return ret;
}

static int ec100_read_snr(struct dvb_frontend *fe, u16 *snr)
{
        *snr = 0;
        return 0;
}

static int ec100_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
{
        *ucblocks = 0;
        return 0;
}

static void ec100_release(struct dvb_frontend *fe)
{
        struct ec100_state *state = fe->demodulator_priv;
        kfree(state);
}

static const struct dvb_frontend_ops ec100_ops;

struct dvb_frontend *ec100_attach(const struct ec100_config *config,
        struct i2c_adapter *i2c)
{
        int ret;
        struct ec100_state *state = NULL;
        u8 tmp;

        /* allocate memory for the internal state */
        state = kzalloc_obj(struct ec100_state);
        if (state == NULL)
                goto error;

        /* setup the state */
        state->i2c = i2c;
        memcpy(&state->config, config, sizeof(struct ec100_config));

        /* check if the demod is there */
        ret = ec100_read_reg(state, 0x33, &tmp);
        if (ret || tmp != 0x0b)
                goto error;

        /* create dvb_frontend */
        memcpy(&state->frontend.ops, &ec100_ops,
                sizeof(struct dvb_frontend_ops));
        state->frontend.demodulator_priv = state;

        return &state->frontend;
error:
        kfree(state);
        return NULL;
}
EXPORT_SYMBOL_GPL(ec100_attach);

static const struct dvb_frontend_ops ec100_ops = {
        .delsys = { SYS_DVBT },
        .info = {
                .name = "E3C EC100 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_MUTE_TS
        },

        .release = ec100_release,
        .set_frontend = ec100_set_frontend,
        .get_tune_settings = ec100_get_tune_settings,
        .read_status = ec100_read_status,
        .read_ber = ec100_read_ber,
        .read_signal_strength = ec100_read_signal_strength,
        .read_snr = ec100_read_snr,
        .read_ucblocks = ec100_read_ucblocks,
};

MODULE_AUTHOR("Antti Palosaari <crope@iki.fi>");
MODULE_DESCRIPTION("E3C EC100 DVB-T demodulator driver");
MODULE_LICENSE("GPL");