// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *    Support for AltoBeam GB20600 (a.k.a DMB-TH) demodulator
 *    ATBM8830, ATBM8831
 *
 *    Copyright (C) 2009 David T.L. Wong <davidtlwong@gmail.com>
 */

#include <asm/div64.h>
#include <media/dvb_frontend.h>

#include "atbm8830.h"
#include "atbm8830_priv.h"

#define dprintk(args...) \
        do { \
                if (debug) \
                        printk(KERN_DEBUG "atbm8830: " args); \
        } while (0)

static int debug;

module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");

static int atbm8830_write_reg(struct atbm_state *priv, u16 reg, u8 data)
{
        int ret = 0;
        u8 dev_addr;
        u8 buf1[] = { reg >> 8, reg & 0xFF };
        u8 buf2[] = { data };
        struct i2c_msg msg1 = { .flags = 0, .buf = buf1, .len = 2 };
        struct i2c_msg msg2 = { .flags = 0, .buf = buf2, .len = 1 };

        dev_addr = priv->config->demod_address;
        msg1.addr = dev_addr;
        msg2.addr = dev_addr;

        if (debug >= 2)
                dprintk("%s: reg=0x%04X, data=0x%02X\n", __func__, reg, data);

        ret = i2c_transfer(priv->i2c, &msg1, 1);
        if (ret != 1)
                return -EIO;

        ret = i2c_transfer(priv->i2c, &msg2, 1);
        return (ret != 1) ? -EIO : 0;
}

static int atbm8830_read_reg(struct atbm_state *priv, u16 reg, u8 *p_data)
{
        int ret;
        u8 dev_addr;

        u8 buf1[] = { reg >> 8, reg & 0xFF };
        u8 buf2[] = { 0 };
        struct i2c_msg msg1 = { .flags = 0, .buf = buf1, .len = 2 };
        struct i2c_msg msg2 = { .flags = I2C_M_RD, .buf = buf2, .len = 1 };

        dev_addr = priv->config->demod_address;
        msg1.addr = dev_addr;
        msg2.addr = dev_addr;

        ret = i2c_transfer(priv->i2c, &msg1, 1);
        if (ret != 1) {
                dprintk("%s: error reg=0x%04x, ret=%i\n", __func__, reg, ret);
                return -EIO;
        }

        ret = i2c_transfer(priv->i2c, &msg2, 1);
        if (ret != 1)
                return -EIO;

        *p_data = buf2[0];
        if (debug >= 2)
                dprintk("%s: reg=0x%04X, data=0x%02X\n",
                        __func__, reg, buf2[0]);

        return 0;
}

/* Lock register latch so that multi-register read is atomic */
static inline int atbm8830_reglatch_lock(struct atbm_state *priv, int lock)
{
        return atbm8830_write_reg(priv, REG_READ_LATCH, lock ? 1 : 0);
}

static int set_osc_freq(struct atbm_state *priv, u32 freq /*in kHz*/)
{
        u32 val;
        u64 t;

        /* 0x100000 * freq / 30.4MHz */
        t = (u64)0x100000 * freq;
        do_div(t, 30400);
        val = t;

        atbm8830_write_reg(priv, REG_OSC_CLK, val);
        atbm8830_write_reg(priv, REG_OSC_CLK + 1, val >> 8);
        atbm8830_write_reg(priv, REG_OSC_CLK + 2, val >> 16);

        return 0;
}

static int set_if_freq(struct atbm_state *priv, u32 freq /*in kHz*/)
{

        u32 fs = priv->config->osc_clk_freq;
        u64 t;
        u32 val;
        u8 dat;

        if (freq != 0) {
                /* 2 * PI * (freq - fs) / fs * (2 ^ 22) */
                t = (u64) 2 * 31416 * (freq - fs);
                t <<= 22;
                do_div(t, fs);
                do_div(t, 1000);
                val = t;

                atbm8830_write_reg(priv, REG_TUNER_BASEBAND, 1);
                atbm8830_write_reg(priv, REG_IF_FREQ, val);
                atbm8830_write_reg(priv, REG_IF_FREQ+1, val >> 8);
                atbm8830_write_reg(priv, REG_IF_FREQ+2, val >> 16);

                atbm8830_read_reg(priv, REG_ADC_CONFIG, &dat);
                dat &= 0xFC;
                atbm8830_write_reg(priv, REG_ADC_CONFIG, dat);
        } else {
                /* Zero IF */
                atbm8830_write_reg(priv, REG_TUNER_BASEBAND, 0);

                atbm8830_read_reg(priv, REG_ADC_CONFIG, &dat);
                dat &= 0xFC;
                dat |= 0x02;
                atbm8830_write_reg(priv, REG_ADC_CONFIG, dat);

                if (priv->config->zif_swap_iq)
                        atbm8830_write_reg(priv, REG_SWAP_I_Q, 0x03);
                else
                        atbm8830_write_reg(priv, REG_SWAP_I_Q, 0x01);
        }

        return 0;
}

static int is_locked(struct atbm_state *priv, u8 *locked)
{
        u8 status;

        atbm8830_read_reg(priv, REG_LOCK_STATUS, &status);

        if (locked != NULL)
                *locked = (status == 1);
        return 0;
}

static int set_agc_config(struct atbm_state *priv,
        u8 min, u8 max, u8 hold_loop)
{
        /* no effect if both min and max are zero */
        if (!min && !max)
            return 0;

        atbm8830_write_reg(priv, REG_AGC_MIN, min);
        atbm8830_write_reg(priv, REG_AGC_MAX, max);
        atbm8830_write_reg(priv, REG_AGC_HOLD_LOOP, hold_loop);

        return 0;
}

static int set_static_channel_mode(struct atbm_state *priv)
{
        int i;

        for (i = 0; i < 5; i++)
                atbm8830_write_reg(priv, 0x099B + i, 0x08);

        atbm8830_write_reg(priv, 0x095B, 0x7F);
        atbm8830_write_reg(priv, 0x09CB, 0x01);
        atbm8830_write_reg(priv, 0x09CC, 0x7F);
        atbm8830_write_reg(priv, 0x09CD, 0x7F);
        atbm8830_write_reg(priv, 0x0E01, 0x20);

        /* For single carrier */
        atbm8830_write_reg(priv, 0x0B03, 0x0A);
        atbm8830_write_reg(priv, 0x0935, 0x10);
        atbm8830_write_reg(priv, 0x0936, 0x08);
        atbm8830_write_reg(priv, 0x093E, 0x08);
        atbm8830_write_reg(priv, 0x096E, 0x06);

        /* frame_count_max0 */
        atbm8830_write_reg(priv, 0x0B09, 0x00);
        /* frame_count_max1 */
        atbm8830_write_reg(priv, 0x0B0A, 0x08);

        return 0;
}

static int set_ts_config(struct atbm_state *priv)
{
        const struct atbm8830_config *cfg = priv->config;

        /*Set parallel/serial ts mode*/
        atbm8830_write_reg(priv, REG_TS_SERIAL, cfg->serial_ts ? 1 : 0);
        atbm8830_write_reg(priv, REG_TS_CLK_MODE, cfg->serial_ts ? 1 : 0);
        /*Set ts sampling edge*/
        atbm8830_write_reg(priv, REG_TS_SAMPLE_EDGE,
                cfg->ts_sampling_edge ? 1 : 0);
        /*Set ts clock freerun*/
        atbm8830_write_reg(priv, REG_TS_CLK_FREERUN,
                cfg->ts_clk_gated ? 0 : 1);

        return 0;
}

static int atbm8830_init(struct dvb_frontend *fe)
{
        struct atbm_state *priv = fe->demodulator_priv;
        const struct atbm8830_config *cfg = priv->config;

        /*Set oscillator frequency*/
        set_osc_freq(priv, cfg->osc_clk_freq);

        /*Set IF frequency*/
        set_if_freq(priv, cfg->if_freq);

        /*Set AGC Config*/
        set_agc_config(priv, cfg->agc_min, cfg->agc_max,
                cfg->agc_hold_loop);

        /*Set static channel mode*/
        set_static_channel_mode(priv);

        set_ts_config(priv);
        /*Turn off DSP reset*/
        atbm8830_write_reg(priv, 0x000A, 0);

        /*SW version test*/
        atbm8830_write_reg(priv, 0x020C, 11);

        /* Run */
        atbm8830_write_reg(priv, REG_DEMOD_RUN, 1);

        return 0;
}


static void atbm8830_release(struct dvb_frontend *fe)
{
        struct atbm_state *state = fe->demodulator_priv;
        dprintk("%s\n", __func__);

        kfree(state);
}

static int atbm8830_set_fe(struct dvb_frontend *fe)
{
        struct atbm_state *priv = fe->demodulator_priv;
        int i;
        u8 locked = 0;
        dprintk("%s\n", __func__);

        /* set frequency */
        if (fe->ops.tuner_ops.set_params) {
                if (fe->ops.i2c_gate_ctrl)
                        fe->ops.i2c_gate_ctrl(fe, 1);
                fe->ops.tuner_ops.set_params(fe);
                if (fe->ops.i2c_gate_ctrl)
                        fe->ops.i2c_gate_ctrl(fe, 0);
        }

        /* start auto lock */
        for (i = 0; i < 10; i++) {
                mdelay(100);
                dprintk("Try %d\n", i);
                is_locked(priv, &locked);
                if (locked != 0) {
                        dprintk("ATBM8830 locked!\n");
                        break;
                }
        }

        return 0;
}

static int atbm8830_get_fe(struct dvb_frontend *fe,
                           struct dtv_frontend_properties *c)
{
        dprintk("%s\n", __func__);

        /* TODO: get real readings from device */
        /* inversion status */
        c->inversion = INVERSION_OFF;

        /* bandwidth */
        c->bandwidth_hz = 8000000;

        c->code_rate_HP = FEC_AUTO;
        c->code_rate_LP = FEC_AUTO;

        c->modulation = QAM_AUTO;

        /* transmission mode */
        c->transmission_mode = TRANSMISSION_MODE_AUTO;

        /* guard interval */
        c->guard_interval = GUARD_INTERVAL_AUTO;

        /* hierarchy */
        c->hierarchy = HIERARCHY_NONE;

        return 0;
}

static int atbm8830_get_tune_settings(struct dvb_frontend *fe,
        struct dvb_frontend_tune_settings *fesettings)
{
        fesettings->min_delay_ms = 0;
        fesettings->step_size = 0;
        fesettings->max_drift = 0;
        return 0;
}

static int atbm8830_read_status(struct dvb_frontend *fe,
                                enum fe_status *fe_status)
{
        struct atbm_state *priv = fe->demodulator_priv;
        u8 locked = 0;
        u8 agc_locked = 0;

        dprintk("%s\n", __func__);
        *fe_status = 0;

        is_locked(priv, &locked);
        if (locked) {
                *fe_status |= FE_HAS_SIGNAL | FE_HAS_CARRIER |
                        FE_HAS_VITERBI | FE_HAS_SYNC | FE_HAS_LOCK;
        }
        dprintk("%s: fe_status=0x%x\n", __func__, *fe_status);

        atbm8830_read_reg(priv, REG_AGC_LOCK, &agc_locked);
        dprintk("AGC Lock: %d\n", agc_locked);

        return 0;
}

static int atbm8830_read_ber(struct dvb_frontend *fe, u32 *ber)
{
        struct atbm_state *priv = fe->demodulator_priv;
        u32 frame_err;
        u8 t;

        dprintk("%s\n", __func__);

        atbm8830_reglatch_lock(priv, 1);

        atbm8830_read_reg(priv, REG_FRAME_ERR_CNT + 1, &t);
        frame_err = t & 0x7F;
        frame_err <<= 8;
        atbm8830_read_reg(priv, REG_FRAME_ERR_CNT, &t);
        frame_err |= t;

        atbm8830_reglatch_lock(priv, 0);

        *ber = frame_err * 100 / 32767;

        dprintk("%s: ber=0x%x\n", __func__, *ber);
        return 0;
}

static int atbm8830_read_signal_strength(struct dvb_frontend *fe, u16 *signal)
{
        struct atbm_state *priv = fe->demodulator_priv;
        u32 pwm;
        u8 t;

        dprintk("%s\n", __func__);
        atbm8830_reglatch_lock(priv, 1);

        atbm8830_read_reg(priv, REG_AGC_PWM_VAL + 1, &t);
        pwm = t & 0x03;
        pwm <<= 8;
        atbm8830_read_reg(priv, REG_AGC_PWM_VAL, &t);
        pwm |= t;

        atbm8830_reglatch_lock(priv, 0);

        dprintk("AGC PWM = 0x%02X\n", pwm);
        pwm = 0x400 - pwm;

        *signal = pwm * 0x10000 / 0x400;

        return 0;
}

static int atbm8830_read_snr(struct dvb_frontend *fe, u16 *snr)
{
        dprintk("%s\n", __func__);
        *snr = 0;
        return 0;
}

static int atbm8830_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
{
        dprintk("%s\n", __func__);
        *ucblocks = 0;
        return 0;
}

static int atbm8830_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
{
        struct atbm_state *priv = fe->demodulator_priv;

        return atbm8830_write_reg(priv, REG_I2C_GATE, enable ? 1 : 0);
}

static const struct dvb_frontend_ops atbm8830_ops = {
        .delsys = { SYS_DTMB },
        .info = {
                .name = "AltoBeam ATBM8830/8831 DMB-TH",
                .frequency_min_hz = 474 * MHz,
                .frequency_max_hz = 858 * MHz,
                .frequency_stepsize_hz = 10 * kHz,
                .caps =
                        FE_CAN_FEC_AUTO |
                        FE_CAN_QAM_AUTO |
                        FE_CAN_TRANSMISSION_MODE_AUTO |
                        FE_CAN_GUARD_INTERVAL_AUTO
        },

        .release = atbm8830_release,

        .init = atbm8830_init,
        .sleep = NULL,
        .write = NULL,
        .i2c_gate_ctrl = atbm8830_i2c_gate_ctrl,

        .set_frontend = atbm8830_set_fe,
        .get_frontend = atbm8830_get_fe,
        .get_tune_settings = atbm8830_get_tune_settings,

        .read_status = atbm8830_read_status,
        .read_ber = atbm8830_read_ber,
        .read_signal_strength = atbm8830_read_signal_strength,
        .read_snr = atbm8830_read_snr,
        .read_ucblocks = atbm8830_read_ucblocks,
};

struct dvb_frontend *atbm8830_attach(const struct atbm8830_config *config,
        struct i2c_adapter *i2c)
{
        struct atbm_state *priv = NULL;
        u8 data = 0;

        dprintk("%s()\n", __func__);

        if (config == NULL || i2c == NULL)
                return NULL;

        priv = kzalloc_obj(struct atbm_state);
        if (priv == NULL)
                goto error_out;

        priv->config = config;
        priv->i2c = i2c;

        /* check if the demod is there */
        if (atbm8830_read_reg(priv, REG_CHIP_ID, &data) != 0) {
                dprintk("%s atbm8830/8831 not found at i2c addr 0x%02X\n",
                        __func__, priv->config->demod_address);
                goto error_out;
        }
        dprintk("atbm8830 chip id: 0x%02X\n", data);

        memcpy(&priv->frontend.ops, &atbm8830_ops,
               sizeof(struct dvb_frontend_ops));
        priv->frontend.demodulator_priv = priv;

        atbm8830_init(&priv->frontend);

        atbm8830_i2c_gate_ctrl(&priv->frontend, 1);

        return &priv->frontend;

error_out:
        dprintk("%s() error_out\n", __func__);
        kfree(priv);
        return NULL;

}
EXPORT_SYMBOL_GPL(atbm8830_attach);

MODULE_DESCRIPTION("AltoBeam ATBM8830/8831 GB20600 demodulator driver");
MODULE_AUTHOR("David T. L. Wong <davidtlwong@gmail.com>");
MODULE_LICENSE("GPL");