// SPDX-License-Identifier: GPL-2.0
/*
 * Sharp QM1D1B0004 satellite tuner
 *
 * Copyright (C) 2014 Akihiro Tsukada <tskd08@gmail.com>
 *
 * based on (former) drivers/media/pci/pt1/va1j5jf8007s.c.
 */

/*
 * Note:
 * Since the data-sheet of this tuner chip is not available,
 * this driver lacks some tuner_ops and config options.
 * In addition, the implementation might be dependent on the specific use
 * in the FE module: VA1J5JF8007S and/or in the product: Earthsoft PT1/PT2.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <media/dvb_frontend.h>
#include "qm1d1b0004.h"

/*
 * Tuner I/F (copied from the former va1j5jf8007s.c)
 * b[0] I2C addr
 * b[1] "0":1, BG:2, divider_quotient[7:3]:5
 * b[2] divider_quotient[2:0]:3, divider_remainder:5
 * b[3] "111":3, LPF[3:2]:2, TM:1, "0":1, REF:1
 * b[4] BANDX, PSC:1, LPF[1:0]:2, DIV:1, "0":1
 *
 * PLL frequency step :=
 *    REF == 0 -> PLL XTL frequency(4MHz) / 8
 *    REF == 1 -> PLL XTL frequency(4MHz) / 4
 *
 * PreScaler :=
 *    PSC == 0 -> x32
 *    PSC == 1 -> x16
 *
 * divider_quotient := (frequency / PLL frequency step) / PreScaler
 * divider_remainder := (frequency / PLL frequency step) % PreScaler
 *
 * LPF := LPF Frequency / 1000 / 2 - 2
 * LPF Frequency @ baudrate=28.86Mbps = 30000
 *
 * band (1..9)
 *   band 1 (freq <  986000) -> DIV:1, BANDX:5, PSC:1
 *   band 2 (freq < 1072000) -> DIV:1, BANDX:6, PSC:1
 *   band 3 (freq < 1154000) -> DIV:1, BANDX:7, PSC:0
 *   band 4 (freq < 1291000) -> DIV:0, BANDX:1, PSC:0
 *   band 5 (freq < 1447000) -> DIV:0, BANDX:2, PSC:0
 *   band 6 (freq < 1615000) -> DIV:0, BANDX:3, PSC:0
 *   band 7 (freq < 1791000) -> DIV:0, BANDX:4, PSC:0
 *   band 8 (freq < 1972000) -> DIV:0, BANDX:5, PSC:0
 *   band 9 (freq < 2150000) -> DIV:0, BANDX:6, PSC:0
 */

#define QM1D1B0004_PSC_MASK (1 << 4)

#define QM1D1B0004_XTL_FREQ 4000
#define QM1D1B0004_LPF_FALLBACK 30000

#if 0 /* Currently unused */
static const struct qm1d1b0004_config default_cfg = {
        .lpf_freq = QM1D1B0004_CFG_LPF_DFLT,
        .half_step = false,
};
#endif

struct qm1d1b0004_state {
        struct qm1d1b0004_config cfg;
        struct i2c_client *i2c;
};


struct qm1d1b0004_cb_map {
        u32 frequency;
        u8 cb;
};

static const struct qm1d1b0004_cb_map cb_maps[] = {
        {  986000, 0xb2 },
        { 1072000, 0xd2 },
        { 1154000, 0xe2 },
        { 1291000, 0x20 },
        { 1447000, 0x40 },
        { 1615000, 0x60 },
        { 1791000, 0x80 },
        { 1972000, 0xa0 },
};

static u8 lookup_cb(u32 frequency)
{
        int i;
        const struct qm1d1b0004_cb_map *map;

        for (i = 0; i < ARRAY_SIZE(cb_maps); i++) {
                map = &cb_maps[i];
                if (frequency < map->frequency)
                        return map->cb;
        }
        return 0xc0;
}

static int qm1d1b0004_set_params(struct dvb_frontend *fe)
{
        struct qm1d1b0004_state *state;
        u32 frequency, pll, lpf_freq;
        u16 word;
        u8 buf[4], cb, lpf;
        int ret;

        state = fe->tuner_priv;
        frequency = fe->dtv_property_cache.frequency;

        pll = QM1D1B0004_XTL_FREQ / 4;
        if (state->cfg.half_step)
                pll /= 2;
        word = DIV_ROUND_CLOSEST(frequency, pll);
        cb = lookup_cb(frequency);
        if (cb & QM1D1B0004_PSC_MASK)
                word = (word << 1 & ~0x1f) | (word & 0x0f);

        /* step.1: set frequency with BG:2, TM:0(4MHZ), LPF:4MHz */
        buf[0] = 0x40 | word >> 8;
        buf[1] = word;
        /* inconsisnten with the above I/F doc. maybe the doc is wrong */
        buf[2] = 0xe0 | state->cfg.half_step;
        buf[3] = cb;
        ret = i2c_master_send(state->i2c, buf, 4);
        if (ret < 0)
                return ret;

        /* step.2: set TM:1 */
        buf[0] = 0xe4 | state->cfg.half_step;
        ret = i2c_master_send(state->i2c, buf, 1);
        if (ret < 0)
                return ret;
        msleep(20);

        /* step.3: set LPF */
        lpf_freq = state->cfg.lpf_freq;
        if (lpf_freq == QM1D1B0004_CFG_LPF_DFLT)
                lpf_freq = fe->dtv_property_cache.symbol_rate / 1000;
        if (lpf_freq == 0)
                lpf_freq = QM1D1B0004_LPF_FALLBACK;
        lpf = DIV_ROUND_UP(lpf_freq, 2000) - 2;
        buf[0] = 0xe4 | ((lpf & 0x0c) << 1) | state->cfg.half_step;
        buf[1] = cb | ((lpf & 0x03) << 2);
        ret = i2c_master_send(state->i2c, buf, 2);
        if (ret < 0)
                return ret;

        /* step.4: read PLL lock? */
        buf[0] = 0;
        ret = i2c_master_recv(state->i2c, buf, 1);
        if (ret < 0)
                return ret;
        return 0;
}


static int qm1d1b0004_set_config(struct dvb_frontend *fe, void *priv_cfg)
{
        struct qm1d1b0004_state *state;

        state = fe->tuner_priv;
        memcpy(&state->cfg, priv_cfg, sizeof(state->cfg));
        return 0;
}


static int qm1d1b0004_init(struct dvb_frontend *fe)
{
        struct qm1d1b0004_state *state;
        u8 buf[2] = {0xf8, 0x04};

        state = fe->tuner_priv;
        if (state->cfg.half_step)
                buf[0] |= 0x01;

        return i2c_master_send(state->i2c, buf, 2);
}


static const struct dvb_tuner_ops qm1d1b0004_ops = {
        .info = {
                .name = "Sharp qm1d1b0004",

                .frequency_min_hz =  950 * MHz,
                .frequency_max_hz = 2150 * MHz,
        },

        .init = qm1d1b0004_init,

        .set_params = qm1d1b0004_set_params,
        .set_config = qm1d1b0004_set_config,
};

static int
qm1d1b0004_probe(struct i2c_client *client)
{
        struct dvb_frontend *fe;
        struct qm1d1b0004_config *cfg;
        struct qm1d1b0004_state *state;
        int ret;

        cfg = client->dev.platform_data;
        fe = cfg->fe;
        i2c_set_clientdata(client, fe);

        fe->tuner_priv = kzalloc_obj(struct qm1d1b0004_state);
        if (!fe->tuner_priv) {
                ret = -ENOMEM;
                goto err_mem;
        }

        memcpy(&fe->ops.tuner_ops, &qm1d1b0004_ops, sizeof(fe->ops.tuner_ops));

        state = fe->tuner_priv;
        state->i2c = client;
        ret = qm1d1b0004_set_config(fe, cfg);
        if (ret != 0)
                goto err_priv;

        dev_info(&client->dev, "Sharp QM1D1B0004 attached.\n");
        return 0;

err_priv:
        kfree(fe->tuner_priv);
err_mem:
        fe->tuner_priv = NULL;
        return ret;
}

static void qm1d1b0004_remove(struct i2c_client *client)
{
        struct dvb_frontend *fe;

        fe = i2c_get_clientdata(client);
        kfree(fe->tuner_priv);
        fe->tuner_priv = NULL;
}


static const struct i2c_device_id qm1d1b0004_id[] = {
        { "qm1d1b0004" },
        {}
};

MODULE_DEVICE_TABLE(i2c, qm1d1b0004_id);

static struct i2c_driver qm1d1b0004_driver = {
        .driver = {
                .name = "qm1d1b0004",
        },
        .probe    = qm1d1b0004_probe,
        .remove   = qm1d1b0004_remove,
        .id_table = qm1d1b0004_id,
};

module_i2c_driver(qm1d1b0004_driver);

MODULE_DESCRIPTION("Sharp QM1D1B0004");
MODULE_AUTHOR("Akihiro Tsukada");
MODULE_LICENSE("GPL");