// SPDX-License-Identifier: GPL-2.0-or-later
/*
        TDA665x tuner driver
        Copyright (C) Manu Abraham (abraham.manu@gmail.com)

*/

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>

#include <media/dvb_frontend.h>
#include "tda665x.h"

struct tda665x_state {
        struct dvb_frontend             *fe;
        struct i2c_adapter              *i2c;
        const struct tda665x_config     *config;

        u32 frequency;
        u32 bandwidth;
};

static int tda665x_read(struct tda665x_state *state, u8 *buf)
{
        const struct tda665x_config *config = state->config;
        int err = 0;
        struct i2c_msg msg = { .addr = config->addr, .flags = I2C_M_RD, .buf = buf, .len = 2 };

        err = i2c_transfer(state->i2c, &msg, 1);
        if (err != 1)
                goto exit;

        return err;
exit:
        printk(KERN_ERR "%s: I/O Error err=<%d>\n", __func__, err);
        return err;
}

static int tda665x_write(struct tda665x_state *state, u8 *buf, u8 length)
{
        const struct tda665x_config *config = state->config;
        int err = 0;
        struct i2c_msg msg = { .addr = config->addr, .flags = 0, .buf = buf, .len = length };

        err = i2c_transfer(state->i2c, &msg, 1);
        if (err != 1)
                goto exit;

        return err;
exit:
        printk(KERN_ERR "%s: I/O Error err=<%d>\n", __func__, err);
        return err;
}

static int tda665x_get_frequency(struct dvb_frontend *fe, u32 *frequency)
{
        struct tda665x_state *state = fe->tuner_priv;

        *frequency = state->frequency;

        return 0;
}

static int tda665x_get_status(struct dvb_frontend *fe, u32 *status)
{
        struct tda665x_state *state = fe->tuner_priv;
        u8 result = 0;
        int err = 0;

        *status = 0;

        err = tda665x_read(state, &result);
        if (err < 0)
                goto exit;

        if ((result >> 6) & 0x01) {
                printk(KERN_DEBUG "%s: Tuner Phase Locked\n", __func__);
                *status = 1;
        }

        return err;
exit:
        printk(KERN_ERR "%s: I/O Error\n", __func__);
        return err;
}

static int tda665x_set_frequency(struct dvb_frontend *fe,
                                 u32 new_frequency)
{
        struct tda665x_state *state = fe->tuner_priv;
        const struct tda665x_config *config = state->config;
        u32 frequency, status = 0;
        u8 buf[4];
        int err = 0;

        if ((new_frequency < config->frequency_max)
            || (new_frequency > config->frequency_min)) {
                printk(KERN_ERR "%s: Frequency beyond limits, frequency=%d\n",
                       __func__, new_frequency);
                return -EINVAL;
        }

        frequency = new_frequency;

        frequency += config->frequency_offst;
        frequency *= config->ref_multiplier;
        frequency += config->ref_divider >> 1;
        frequency /= config->ref_divider;

        buf[0] = (u8) ((frequency & 0x7f00) >> 8);
        buf[1] = (u8) (frequency & 0x00ff) >> 0;
        buf[2] = 0x80 | 0x40 | 0x02;
        buf[3] = 0x00;

        /* restore frequency */
        frequency = new_frequency;

        if (frequency < 153000000) {
                /* VHF-L */
                buf[3] |= 0x01; /* fc, Low Band, 47 - 153 MHz */
                if (frequency < 68000000)
                        buf[3] |= 0x40; /* 83uA */
                if (frequency < 1040000000)
                        buf[3] |= 0x60; /* 122uA */
                if (frequency < 1250000000)
                        buf[3] |= 0x80; /* 163uA */
                else
                        buf[3] |= 0xa0; /* 254uA */
        } else if (frequency < 438000000) {
                /* VHF-H */
                buf[3] |= 0x02; /* fc, Mid Band, 153 - 438 MHz */
                if (frequency < 230000000)
                        buf[3] |= 0x40;
                if (frequency < 300000000)
                        buf[3] |= 0x60;
                else
                        buf[3] |= 0x80;
        } else {
                /* UHF */
                buf[3] |= 0x04; /* fc, High Band, 438 - 862 MHz */
                if (frequency < 470000000)
                        buf[3] |= 0x60;
                if (frequency < 526000000)
                        buf[3] |= 0x80;
                else
                        buf[3] |= 0xa0;
        }

        /* Set params */
        err = tda665x_write(state, buf, 5);
        if (err < 0)
                goto exit;

        /* sleep for some time */
        printk(KERN_DEBUG "%s: Waiting to Phase LOCK\n", __func__);
        msleep(20);
        /* check status */
        err = tda665x_get_status(fe, &status);
        if (err < 0)
                goto exit;

        if (status == 1) {
                printk(KERN_DEBUG "%s: Tuner Phase locked: status=%d\n",
                       __func__, status);
                state->frequency = frequency; /* cache successful state */
        } else {
                printk(KERN_ERR "%s: No Phase lock: status=%d\n",
                       __func__, status);
        }

        return 0;
exit:
        printk(KERN_ERR "%s: I/O Error\n", __func__);
        return err;
}

static int tda665x_set_params(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;

        tda665x_set_frequency(fe, c->frequency);

        return 0;
}

static void tda665x_release(struct dvb_frontend *fe)
{
        struct tda665x_state *state = fe->tuner_priv;

        fe->tuner_priv = NULL;
        kfree(state);
}

static const struct dvb_tuner_ops tda665x_ops = {
        .get_status     = tda665x_get_status,
        .set_params     = tda665x_set_params,
        .get_frequency  = tda665x_get_frequency,
        .release        = tda665x_release
};

struct dvb_frontend *tda665x_attach(struct dvb_frontend *fe,
                                    const struct tda665x_config *config,
                                    struct i2c_adapter *i2c)
{
        struct tda665x_state *state = NULL;
        struct dvb_tuner_info *info;

        state = kzalloc_obj(struct tda665x_state);
        if (!state)
                return NULL;

        state->config           = config;
        state->i2c              = i2c;
        state->fe               = fe;
        fe->tuner_priv          = state;
        fe->ops.tuner_ops       = tda665x_ops;
        info                     = &fe->ops.tuner_ops.info;

        memcpy(info->name, config->name, sizeof(config->name));
        info->frequency_min_hz  = config->frequency_min;
        info->frequency_max_hz  = config->frequency_max;
        info->frequency_step_hz = config->frequency_offst;

        printk(KERN_DEBUG "%s: Attaching TDA665x (%s) tuner\n", __func__, info->name);

        return fe;
}
EXPORT_SYMBOL_GPL(tda665x_attach);

MODULE_DESCRIPTION("TDA665x driver");
MODULE_AUTHOR("Manu Abraham");
MODULE_LICENSE("GPL");