// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Driver for Freescale MC44S803 Low Power CMOS Broadband Tuner
 *
 *  Copyright (c) 2009 Jochen Friedrich <jochen@scram.de>
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/dvb/frontend.h>
#include <linux/i2c.h>
#include <linux/slab.h>

#include <media/dvb_frontend.h>

#include "mc44s803.h"
#include "mc44s803_priv.h"

#define mc_printk(level, format, arg...)        \
        printk(level "mc44s803: " format , ## arg)

/* Writes a single register */
static int mc44s803_writereg(struct mc44s803_priv *priv, u32 val)
{
        u8 buf[3];
        struct i2c_msg msg = {
                .addr = priv->cfg->i2c_address, .flags = 0, .buf = buf, .len = 3
        };

        buf[0] = (val & 0xff0000) >> 16;
        buf[1] = (val & 0xff00) >> 8;
        buf[2] = (val & 0xff);

        if (i2c_transfer(priv->i2c, &msg, 1) != 1) {
                mc_printk(KERN_WARNING, "I2C write failed\n");
                return -EREMOTEIO;
        }
        return 0;
}

/* Reads a single register */
static int mc44s803_readreg(struct mc44s803_priv *priv, u8 reg, u32 *val)
{
        u32 wval;
        u8 buf[3];
        int ret;
        struct i2c_msg msg[] = {
                { .addr = priv->cfg->i2c_address, .flags = I2C_M_RD,
                  .buf = buf, .len = 3 },
        };

        wval = MC44S803_REG_SM(MC44S803_REG_DATAREG, MC44S803_ADDR) |
               MC44S803_REG_SM(reg, MC44S803_D);

        ret = mc44s803_writereg(priv, wval);
        if (ret)
                return ret;

        if (i2c_transfer(priv->i2c, msg, 1) != 1) {
                mc_printk(KERN_WARNING, "I2C read failed\n");
                return -EREMOTEIO;
        }

        *val = (buf[0] << 16) | (buf[1] << 8) | buf[2];

        return 0;
}

static void mc44s803_release(struct dvb_frontend *fe)
{
        struct mc44s803_priv *priv = fe->tuner_priv;

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

static int mc44s803_init(struct dvb_frontend *fe)
{
        struct mc44s803_priv *priv = fe->tuner_priv;
        u32 val;
        int err;

        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 1);

/* Reset chip */
        val = MC44S803_REG_SM(MC44S803_REG_RESET, MC44S803_ADDR) |
              MC44S803_REG_SM(1, MC44S803_RS);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

        val = MC44S803_REG_SM(MC44S803_REG_RESET, MC44S803_ADDR);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

/* Power Up and Start Osc */

        val = MC44S803_REG_SM(MC44S803_REG_REFOSC, MC44S803_ADDR) |
              MC44S803_REG_SM(0xC0, MC44S803_REFOSC) |
              MC44S803_REG_SM(1, MC44S803_OSCSEL);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

        val = MC44S803_REG_SM(MC44S803_REG_POWER, MC44S803_ADDR) |
              MC44S803_REG_SM(0x200, MC44S803_POWER);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

        msleep(10);

        val = MC44S803_REG_SM(MC44S803_REG_REFOSC, MC44S803_ADDR) |
              MC44S803_REG_SM(0x40, MC44S803_REFOSC) |
              MC44S803_REG_SM(1, MC44S803_OSCSEL);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

        msleep(20);

/* Setup Mixer */

        val = MC44S803_REG_SM(MC44S803_REG_MIXER, MC44S803_ADDR) |
              MC44S803_REG_SM(1, MC44S803_TRI_STATE) |
              MC44S803_REG_SM(0x7F, MC44S803_MIXER_RES);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

/* Setup Cirquit Adjust */

        val = MC44S803_REG_SM(MC44S803_REG_CIRCADJ, MC44S803_ADDR) |
              MC44S803_REG_SM(1, MC44S803_G1) |
              MC44S803_REG_SM(1, MC44S803_G3) |
              MC44S803_REG_SM(0x3, MC44S803_CIRCADJ_RES) |
              MC44S803_REG_SM(1, MC44S803_G6) |
              MC44S803_REG_SM(priv->cfg->dig_out, MC44S803_S1) |
              MC44S803_REG_SM(0x3, MC44S803_LP) |
              MC44S803_REG_SM(1, MC44S803_CLRF) |
              MC44S803_REG_SM(1, MC44S803_CLIF);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

        val = MC44S803_REG_SM(MC44S803_REG_CIRCADJ, MC44S803_ADDR) |
              MC44S803_REG_SM(1, MC44S803_G1) |
              MC44S803_REG_SM(1, MC44S803_G3) |
              MC44S803_REG_SM(0x3, MC44S803_CIRCADJ_RES) |
              MC44S803_REG_SM(1, MC44S803_G6) |
              MC44S803_REG_SM(priv->cfg->dig_out, MC44S803_S1) |
              MC44S803_REG_SM(0x3, MC44S803_LP);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

/* Setup Digtune */

        val = MC44S803_REG_SM(MC44S803_REG_DIGTUNE, MC44S803_ADDR) |
              MC44S803_REG_SM(3, MC44S803_XOD);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

/* Setup AGC */

        val = MC44S803_REG_SM(MC44S803_REG_LNAAGC, MC44S803_ADDR) |
              MC44S803_REG_SM(1, MC44S803_AT1) |
              MC44S803_REG_SM(1, MC44S803_AT2) |
              MC44S803_REG_SM(1, MC44S803_AGC_AN_DIG) |
              MC44S803_REG_SM(1, MC44S803_AGC_READ_EN) |
              MC44S803_REG_SM(1, MC44S803_LNA0);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0);
        return 0;

exit:
        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0);

        mc_printk(KERN_WARNING, "I/O Error\n");
        return err;
}

static int mc44s803_set_params(struct dvb_frontend *fe)
{
        struct mc44s803_priv *priv = fe->tuner_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        u32 r1, r2, n1, n2, lo1, lo2, freq, val;
        int err;

        priv->frequency = c->frequency;

        r1 = MC44S803_OSC / 1000000;
        r2 = MC44S803_OSC /  100000;

        n1 = (c->frequency + MC44S803_IF1 + 500000) / 1000000;
        freq = MC44S803_OSC / r1 * n1;
        lo1 = ((60 * n1) + (r1 / 2)) / r1;
        freq = freq - c->frequency;

        n2 = (freq - MC44S803_IF2 + 50000) / 100000;
        lo2 = ((60 * n2) + (r2 / 2)) / r2;

        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 1);

        val = MC44S803_REG_SM(MC44S803_REG_REFDIV, MC44S803_ADDR) |
              MC44S803_REG_SM(r1-1, MC44S803_R1) |
              MC44S803_REG_SM(r2-1, MC44S803_R2) |
              MC44S803_REG_SM(1, MC44S803_REFBUF_EN);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

        val = MC44S803_REG_SM(MC44S803_REG_LO1, MC44S803_ADDR) |
              MC44S803_REG_SM(n1-2, MC44S803_LO1);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

        val = MC44S803_REG_SM(MC44S803_REG_LO2, MC44S803_ADDR) |
              MC44S803_REG_SM(n2-2, MC44S803_LO2);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

        val = MC44S803_REG_SM(MC44S803_REG_DIGTUNE, MC44S803_ADDR) |
              MC44S803_REG_SM(1, MC44S803_DA) |
              MC44S803_REG_SM(lo1, MC44S803_LO_REF) |
              MC44S803_REG_SM(1, MC44S803_AT);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

        val = MC44S803_REG_SM(MC44S803_REG_DIGTUNE, MC44S803_ADDR) |
              MC44S803_REG_SM(2, MC44S803_DA) |
              MC44S803_REG_SM(lo2, MC44S803_LO_REF) |
              MC44S803_REG_SM(1, MC44S803_AT);

        err = mc44s803_writereg(priv, val);
        if (err)
                goto exit;

        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0);

        return 0;

exit:
        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0);

        mc_printk(KERN_WARNING, "I/O Error\n");
        return err;
}

static int mc44s803_get_frequency(struct dvb_frontend *fe, u32 *frequency)
{
        struct mc44s803_priv *priv = fe->tuner_priv;
        *frequency = priv->frequency;
        return 0;
}

static int mc44s803_get_if_frequency(struct dvb_frontend *fe, u32 *frequency)
{
        *frequency = MC44S803_IF2; /* 36.125 MHz */
        return 0;
}

static const struct dvb_tuner_ops mc44s803_tuner_ops = {
        .info = {
                .name              = "Freescale MC44S803",
                .frequency_min_hz  =   48 * MHz,
                .frequency_max_hz  = 1000 * MHz,
                .frequency_step_hz =  100 * kHz,
        },

        .release       = mc44s803_release,
        .init          = mc44s803_init,
        .set_params    = mc44s803_set_params,
        .get_frequency = mc44s803_get_frequency,
        .get_if_frequency = mc44s803_get_if_frequency,
};

/* This functions tries to identify a MC44S803 tuner by reading the ID
   register. This is hasty. */
struct dvb_frontend *mc44s803_attach(struct dvb_frontend *fe,
         struct i2c_adapter *i2c, struct mc44s803_config *cfg)
{
        struct mc44s803_priv *priv;
        u32 reg;
        u8 id;
        int ret;

        reg = 0;

        priv = kzalloc_obj(struct mc44s803_priv);
        if (priv == NULL)
                return NULL;

        priv->cfg = cfg;
        priv->i2c = i2c;
        priv->fe  = fe;

        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */

        ret = mc44s803_readreg(priv, MC44S803_REG_ID, &reg);
        if (ret)
                goto error;

        id = MC44S803_REG_MS(reg, MC44S803_ID);

        if (id != 0x14) {
                mc_printk(KERN_ERR, "unsupported ID (%x should be 0x14)\n",
                          id);
                goto error;
        }

        mc_printk(KERN_INFO, "successfully identified (ID = %x)\n", id);
        memcpy(&fe->ops.tuner_ops, &mc44s803_tuner_ops,
               sizeof(struct dvb_tuner_ops));

        fe->tuner_priv = priv;

        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */

        return fe;

error:
        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */

        kfree(priv);
        return NULL;
}
EXPORT_SYMBOL_GPL(mc44s803_attach);

MODULE_AUTHOR("Jochen Friedrich");
MODULE_DESCRIPTION("Freescale MC44S803 silicon tuner driver");
MODULE_LICENSE("GPL");