// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Driver for Microtune MT2060 "Single chip dual conversion broadband tuner"
 *
 *  Copyright (c) 2006 Olivier DANET <odanet@caramail.com>
 */

/* In that file, frequencies are expressed in kiloHertz to avoid 32 bits overflows */

#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 "mt2060.h"
#include "mt2060_priv.h"

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

#define dprintk(args...) do { if (debug) {printk(KERN_DEBUG "MT2060: " args); printk("\n"); }} while (0)

// Reads a single register
static int mt2060_readreg(struct mt2060_priv *priv, u8 reg, u8 *val)
{
        struct i2c_msg msg[2] = {
                { .addr = priv->cfg->i2c_address, .flags = 0, .len = 1 },
                { .addr = priv->cfg->i2c_address, .flags = I2C_M_RD, .len = 1 },
        };
        int rc = 0;
        u8 *b;

        b = kmalloc(2, GFP_KERNEL);
        if (!b)
                return -ENOMEM;

        b[0] = reg;
        b[1] = 0;

        msg[0].buf = b;
        msg[1].buf = b + 1;

        if (i2c_transfer(priv->i2c, msg, 2) != 2) {
                printk(KERN_WARNING "mt2060 I2C read failed\n");
                rc = -EREMOTEIO;
        }
        *val = b[1];
        kfree(b);

        return rc;
}

// Writes a single register
static int mt2060_writereg(struct mt2060_priv *priv, u8 reg, u8 val)
{
        struct i2c_msg msg = {
                .addr = priv->cfg->i2c_address, .flags = 0, .len = 2
        };
        u8 *buf;
        int rc = 0;

        buf = kmalloc(2, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        buf[0] = reg;
        buf[1] = val;

        msg.buf = buf;

        if (i2c_transfer(priv->i2c, &msg, 1) != 1) {
                printk(KERN_WARNING "mt2060 I2C write failed\n");
                rc = -EREMOTEIO;
        }
        kfree(buf);
        return rc;
}

// Writes a set of consecutive registers
static int mt2060_writeregs(struct mt2060_priv *priv,u8 *buf, u8 len)
{
        int rem, val_len;
        u8 *xfer_buf;
        int rc = 0;
        struct i2c_msg msg = {
                .addr = priv->cfg->i2c_address, .flags = 0
        };

        xfer_buf = kmalloc(16, GFP_KERNEL);
        if (!xfer_buf)
                return -ENOMEM;

        msg.buf = xfer_buf;

        for (rem = len - 1; rem > 0; rem -= priv->i2c_max_regs) {
                val_len = min_t(int, rem, priv->i2c_max_regs);
                msg.len = 1 + val_len;
                xfer_buf[0] = buf[0] + len - 1 - rem;
                memcpy(&xfer_buf[1], &buf[1 + len - 1 - rem], val_len);

                if (i2c_transfer(priv->i2c, &msg, 1) != 1) {
                        printk(KERN_WARNING "mt2060 I2C write failed (len=%i)\n", val_len);
                        rc = -EREMOTEIO;
                        break;
                }
        }

        kfree(xfer_buf);
        return rc;
}

// Initialisation sequences
// LNABAND=3, NUM1=0x3C, DIV1=0x74, NUM2=0x1080, DIV2=0x49
static u8 mt2060_config1[] = {
        REG_LO1C1,
        0x3F,   0x74,   0x00,   0x08,   0x93
};

// FMCG=2, GP2=0, GP1=0
static u8 mt2060_config2[] = {
        REG_MISC_CTRL,
        0x20,   0x1E,   0x30,   0xff,   0x80,   0xff,   0x00,   0x2c,   0x42
};

//  VGAG=3, V1CSE=1

#ifdef  MT2060_SPURCHECK
/* The function below calculates the frequency offset between the output frequency if2
 and the closer cross modulation subcarrier between lo1 and lo2 up to the tenth harmonic */
static int mt2060_spurcalc(u32 lo1,u32 lo2,u32 if2)
{
        int I,J;
        int dia,diamin,diff;
        diamin=1000000;
        for (I = 1; I < 10; I++) {
                J = ((2*I*lo1)/lo2+1)/2;
                diff = I*(int)lo1-J*(int)lo2;
                if (diff < 0) diff=-diff;
                dia = (diff-(int)if2);
                if (dia < 0) dia=-dia;
                if (diamin > dia) diamin=dia;
        }
        return diamin;
}

#define BANDWIDTH 4000 // kHz

/* Calculates the frequency offset to add to avoid spurs. Returns 0 if no offset is needed */
static int mt2060_spurcheck(u32 lo1,u32 lo2,u32 if2)
{
        u32 Spur,Sp1,Sp2;
        int I,J;
        I=0;
        J=1000;

        Spur=mt2060_spurcalc(lo1,lo2,if2);
        if (Spur < BANDWIDTH) {
                /* Potential spurs detected */
                dprintk("Spurs before : f_lo1: %d  f_lo2: %d  (kHz)",
                        (int)lo1,(int)lo2);
                I=1000;
                Sp1 = mt2060_spurcalc(lo1+I,lo2+I,if2);
                Sp2 = mt2060_spurcalc(lo1-I,lo2-I,if2);

                if (Sp1 < Sp2) {
                        J=-J; I=-I; Spur=Sp2;
                } else
                        Spur=Sp1;

                while (Spur < BANDWIDTH) {
                        I += J;
                        Spur = mt2060_spurcalc(lo1+I,lo2+I,if2);
                }
                dprintk("Spurs after  : f_lo1: %d  f_lo2: %d  (kHz)",
                        (int)(lo1+I),(int)(lo2+I));
        }
        return I;
}
#endif

#define IF2  36150       // IF2 frequency = 36.150 MHz
#define FREF 16000       // Quartz oscillator 16 MHz

static int mt2060_set_params(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        struct mt2060_priv *priv;
        int i=0;
        u32 freq;
        u8  lnaband;
        u32 f_lo1,f_lo2;
        u32 div1,num1,div2,num2;
        u8  b[8];
        u32 if1;

        priv = fe->tuner_priv;

        if1 = priv->if1_freq;
        b[0] = REG_LO1B1;
        b[1] = 0xFF;

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

        mt2060_writeregs(priv,b,2);

        freq = c->frequency / 1000; /* Hz -> kHz */

        f_lo1 = freq + if1 * 1000;
        f_lo1 = (f_lo1 / 250) * 250;
        f_lo2 = f_lo1 - freq - IF2;
        // From the Comtech datasheet, the step used is 50kHz. The tuner chip could be more precise
        f_lo2 = ((f_lo2 + 25) / 50) * 50;
        priv->frequency =  (f_lo1 - f_lo2 - IF2) * 1000;

#ifdef MT2060_SPURCHECK
        // LO-related spurs detection and correction
        num1   = mt2060_spurcheck(f_lo1,f_lo2,IF2);
        f_lo1 += num1;
        f_lo2 += num1;
#endif
        //Frequency LO1 = 16MHz * (DIV1 + NUM1/64 )
        num1 = f_lo1 / (FREF / 64);
        div1 = num1 / 64;
        num1 &= 0x3f;

        // Frequency LO2 = 16MHz * (DIV2 + NUM2/8192 )
        num2 = f_lo2 * 64 / (FREF / 128);
        div2 = num2 / 8192;
        num2 &= 0x1fff;

        if (freq <=  95000) lnaband = 0xB0; else
        if (freq <= 180000) lnaband = 0xA0; else
        if (freq <= 260000) lnaband = 0x90; else
        if (freq <= 335000) lnaband = 0x80; else
        if (freq <= 425000) lnaband = 0x70; else
        if (freq <= 480000) lnaband = 0x60; else
        if (freq <= 570000) lnaband = 0x50; else
        if (freq <= 645000) lnaband = 0x40; else
        if (freq <= 730000) lnaband = 0x30; else
        if (freq <= 810000) lnaband = 0x20; else lnaband = 0x10;

        b[0] = REG_LO1C1;
        b[1] = lnaband | ((num1 >>2) & 0x0F);
        b[2] = div1;
        b[3] = (num2 & 0x0F)  | ((num1 & 3) << 4);
        b[4] = num2 >> 4;
        b[5] = ((num2 >>12) & 1) | (div2 << 1);

        dprintk("IF1: %dMHz",(int)if1);
        dprintk("PLL freq=%dkHz  f_lo1=%dkHz  f_lo2=%dkHz",(int)freq,(int)f_lo1,(int)f_lo2);
        dprintk("PLL div1=%d  num1=%d  div2=%d  num2=%d",(int)div1,(int)num1,(int)div2,(int)num2);
        dprintk("PLL [1..5]: %2x %2x %2x %2x %2x",(int)b[1],(int)b[2],(int)b[3],(int)b[4],(int)b[5]);

        mt2060_writeregs(priv,b,6);

        //Waits for pll lock or timeout
        i = 0;
        do {
                mt2060_readreg(priv,REG_LO_STATUS,b);
                if ((b[0] & 0x88)==0x88)
                        break;
                msleep(4);
                i++;
        } while (i<10);

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

        return 0;
}

static void mt2060_calibrate(struct mt2060_priv *priv)
{
        u8 b = 0;
        int i = 0;

        if (mt2060_writeregs(priv,mt2060_config1,sizeof(mt2060_config1)))
                return;
        if (mt2060_writeregs(priv,mt2060_config2,sizeof(mt2060_config2)))
                return;

        /* initialize the clock output */
        mt2060_writereg(priv, REG_VGAG, (priv->cfg->clock_out << 6) | 0x30);

        do {
                b |= (1 << 6); // FM1SS;
                mt2060_writereg(priv, REG_LO2C1,b);
                msleep(20);

                if (i == 0) {
                        b |= (1 << 7); // FM1CA;
                        mt2060_writereg(priv, REG_LO2C1,b);
                        b &= ~(1 << 7); // FM1CA;
                        msleep(20);
                }

                b &= ~(1 << 6); // FM1SS
                mt2060_writereg(priv, REG_LO2C1,b);

                msleep(20);
                i++;
        } while (i < 9);

        i = 0;
        while (i++ < 10 && mt2060_readreg(priv, REG_MISC_STAT, &b) == 0 && (b & (1 << 6)) == 0)
                msleep(20);

        if (i <= 10) {
                mt2060_readreg(priv, REG_FM_FREQ, &priv->fmfreq); // now find out, what is fmreq used for :)
                dprintk("calibration was successful: %d", (int)priv->fmfreq);
        } else
                dprintk("FMCAL timed out");
}

static int mt2060_get_frequency(struct dvb_frontend *fe, u32 *frequency)
{
        struct mt2060_priv *priv = fe->tuner_priv;
        *frequency = priv->frequency;
        return 0;
}

static int mt2060_get_if_frequency(struct dvb_frontend *fe, u32 *frequency)
{
        *frequency = IF2 * 1000;
        return 0;
}

static int mt2060_init(struct dvb_frontend *fe)
{
        struct mt2060_priv *priv = fe->tuner_priv;
        int ret;

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

        if (priv->sleep) {
                ret = mt2060_writereg(priv, REG_MISC_CTRL, 0x20);
                if (ret)
                        goto err_i2c_gate_ctrl;
        }

        ret = mt2060_writereg(priv, REG_VGAG,
                              (priv->cfg->clock_out << 6) | 0x33);

err_i2c_gate_ctrl:
        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */

        return ret;
}

static int mt2060_sleep(struct dvb_frontend *fe)
{
        struct mt2060_priv *priv = fe->tuner_priv;
        int ret;

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

        ret = mt2060_writereg(priv, REG_VGAG,
                              (priv->cfg->clock_out << 6) | 0x30);
        if (ret)
                goto err_i2c_gate_ctrl;

        if (priv->sleep)
                ret = mt2060_writereg(priv, REG_MISC_CTRL, 0xe8);

err_i2c_gate_ctrl:
        if (fe->ops.i2c_gate_ctrl)
                fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */

        return ret;
}

static void mt2060_release(struct dvb_frontend *fe)
{
        kfree(fe->tuner_priv);
        fe->tuner_priv = NULL;
}

static const struct dvb_tuner_ops mt2060_tuner_ops = {
        .info = {
                .name              = "Microtune MT2060",
                .frequency_min_hz  =  48 * MHz,
                .frequency_max_hz  = 860 * MHz,
                .frequency_step_hz =  50 * kHz,
        },

        .release       = mt2060_release,

        .init          = mt2060_init,
        .sleep         = mt2060_sleep,

        .set_params    = mt2060_set_params,
        .get_frequency = mt2060_get_frequency,
        .get_if_frequency = mt2060_get_if_frequency,
};

/* This functions tries to identify a MT2060 tuner by reading the PART/REV register. This is hasty. */
struct dvb_frontend * mt2060_attach(struct dvb_frontend *fe, struct i2c_adapter *i2c, struct mt2060_config *cfg, u16 if1)
{
        struct mt2060_priv *priv = NULL;
        u8 id = 0;

        priv = kzalloc_obj(struct mt2060_priv);
        if (priv == NULL)
                return NULL;

        priv->cfg      = cfg;
        priv->i2c      = i2c;
        priv->if1_freq = if1;
        priv->i2c_max_regs = ~0;

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

        if (mt2060_readreg(priv,REG_PART_REV,&id) != 0) {
                kfree(priv);
                return NULL;
        }

        if (id != PART_REV) {
                kfree(priv);
                return NULL;
        }
        printk(KERN_INFO "MT2060: successfully identified (IF1 = %d)\n", if1);
        memcpy(&fe->ops.tuner_ops, &mt2060_tuner_ops, sizeof(struct dvb_tuner_ops));

        fe->tuner_priv = priv;

        mt2060_calibrate(priv);

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

        return fe;
}
EXPORT_SYMBOL_GPL(mt2060_attach);

static int mt2060_probe(struct i2c_client *client)
{
        struct mt2060_platform_data *pdata = client->dev.platform_data;
        struct dvb_frontend *fe;
        struct mt2060_priv *dev;
        int ret;
        u8 chip_id;

        dev_dbg(&client->dev, "\n");

        if (!pdata) {
                dev_err(&client->dev, "Cannot proceed without platform data\n");
                ret = -EINVAL;
                goto err;
        }

        dev = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
        if (!dev) {
                ret = -ENOMEM;
                goto err;
        }

        fe = pdata->dvb_frontend;
        dev->config.i2c_address = client->addr;
        dev->config.clock_out = pdata->clock_out;
        dev->cfg = &dev->config;
        dev->i2c = client->adapter;
        dev->if1_freq = pdata->if1 ? pdata->if1 : 1220;
        dev->client = client;
        dev->i2c_max_regs = pdata->i2c_write_max ? pdata->i2c_write_max - 1 : ~0;
        dev->sleep = true;

        ret = mt2060_readreg(dev, REG_PART_REV, &chip_id);
        if (ret) {
                ret = -ENODEV;
                goto err;
        }

        dev_dbg(&client->dev, "chip id=%02x\n", chip_id);

        if (chip_id != PART_REV) {
                ret = -ENODEV;
                goto err;
        }

        /* Power on, calibrate, sleep */
        ret = mt2060_writereg(dev, REG_MISC_CTRL, 0x20);
        if (ret)
                goto err;
        mt2060_calibrate(dev);
        ret = mt2060_writereg(dev, REG_MISC_CTRL, 0xe8);
        if (ret)
                goto err;

        dev_info(&client->dev, "Microtune MT2060 successfully identified\n");
        memcpy(&fe->ops.tuner_ops, &mt2060_tuner_ops, sizeof(fe->ops.tuner_ops));
        fe->ops.tuner_ops.release = NULL;
        fe->tuner_priv = dev;
        i2c_set_clientdata(client, dev);

        return 0;
err:
        dev_dbg(&client->dev, "failed=%d\n", ret);
        return ret;
}

static void mt2060_remove(struct i2c_client *client)
{
        dev_dbg(&client->dev, "\n");
}

static const struct i2c_device_id mt2060_id_table[] = {
        { "mt2060" },
        {}
};
MODULE_DEVICE_TABLE(i2c, mt2060_id_table);

static struct i2c_driver mt2060_driver = {
        .driver = {
                .name = "mt2060",
                .suppress_bind_attrs = true,
        },
        .probe          = mt2060_probe,
        .remove         = mt2060_remove,
        .id_table       = mt2060_id_table,
};

module_i2c_driver(mt2060_driver);

MODULE_AUTHOR("Olivier DANET");
MODULE_DESCRIPTION("Microtune MT2060 silicon tuner driver");
MODULE_LICENSE("GPL");