stv6110.c

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/*
 * stv6110.c
 *
 * Driver for ST STV6110 satellite tuner IC.
 *
 * Copyright (C) 2009 NetUP Inc.
 * Copyright (C) 2009 Igor M. Liplianin <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

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

#include <linux/types.h>

#include "stv6110.h"

static int debug;

struct stv6110_priv {
    int i2c_address;
    struct i2c_adapter *i2c;

    u32 mclk;
    u8 clk_div;
    u8 gain;
    u8 regs[8];
};

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

static s32 abssub(s32 a, s32 b)
{
    if (a > b)
        return a - b;
    else
        return b - a;
};

static int stv6110_release(struct dvb_frontend *fe)
{
    kfree(fe->tuner_priv);
    fe->tuner_priv = NULL;
    return 0;
}

static int stv6110_write_regs(struct dvb_frontend *fe, u8 buf[],
                            int start, int len)
{
    struct stv6110_priv *priv = fe->tuner_priv;
    int rc;
    u8 cmdbuf[len + 1];
    struct i2c_msg msg = {
        .addr   = priv->i2c_address,
        .flags  = 0,
        .buf    = cmdbuf,
        .len    = len + 1
    };

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

    if (start + len > 8)
        return -EINVAL;

    memcpy(&cmdbuf[1], buf, len);
    cmdbuf[0] = start;

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

    rc = i2c_transfer(priv->i2c, &msg, 1);
    if (rc != 1)
        dprintk("%s: i2c error\n", __func__);

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

    return 0;
}

static int stv6110_read_regs(struct dvb_frontend *fe, u8 regs[],
                            int start, int len)
{
    struct stv6110_priv *priv = fe->tuner_priv;
    int rc;
    u8 reg[] = { start };
    struct i2c_msg msg[] = {
        {
            .addr   = priv->i2c_address,
            .flags  = 0,
            .buf    = reg,
            .len    = 1,
        }, {
            .addr   = priv->i2c_address,
            .flags  = I2C_M_RD,
            .buf    = regs,
            .len    = len,
        },
    };

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

    rc = i2c_transfer(priv->i2c, msg, 2);
    if (rc != 2)
        dprintk("%s: i2c error\n", __func__);

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

    memcpy(&priv->regs[start], regs, len);

    return 0;
}

static int stv6110_read_reg(struct dvb_frontend *fe, int start)
{
    u8 buf[] = { 0 };
    stv6110_read_regs(fe, buf, start, 1);

    return buf[0];
}

static int stv6110_sleep(struct dvb_frontend *fe)
{
    u8 reg[] = { 0 };
    stv6110_write_regs(fe, reg, 0, 1);

    return 0;
}

static u32 carrier_width(u32 symbol_rate, fe_rolloff_t rolloff)
{
    u32 rlf;

    switch (rolloff) {
    case ROLLOFF_20:
        rlf = 20;
        break;
    case ROLLOFF_25:
        rlf = 25;
        break;
    default:
        rlf = 35;
        break;
    }

    return symbol_rate  + ((symbol_rate * rlf) / 100);
}

static int stv6110_set_bandwidth(struct dvb_frontend *fe, u32 bandwidth)
{
    struct stv6110_priv *priv = fe->tuner_priv;
    u8 r8, ret = 0x04;
    int i;

    if ((bandwidth / 2) > 36000000) /*BW/2 max=31+5=36 mhz for r8=31*/
        r8 = 31;
    else if ((bandwidth / 2) < 5000000) /* BW/2 min=5Mhz for F=0 */
        r8 = 0;
    else /*if 5 < BW/2 < 36*/
        r8 = (bandwidth / 2) / 1000000 - 5;

    /* ctrl3, RCCLKOFF = 0 Activate the calibration Clock */
    /* ctrl3, CF = r8 Set the LPF value */
    priv->regs[RSTV6110_CTRL3] &= ~((1 << 6) | 0x1f);
    priv->regs[RSTV6110_CTRL3] |= (r8 & 0x1f);
    stv6110_write_regs(fe, &priv->regs[RSTV6110_CTRL3], RSTV6110_CTRL3, 1);
    /* stat1, CALRCSTRT = 1 Start LPF auto calibration*/
    priv->regs[RSTV6110_STAT1] |= 0x02;
    stv6110_write_regs(fe, &priv->regs[RSTV6110_STAT1], RSTV6110_STAT1, 1);

    i = 0;
    /* Wait for CALRCSTRT == 0 */
    while ((i < 10) && (ret != 0)) {
        ret = ((stv6110_read_reg(fe, RSTV6110_STAT1)) & 0x02);
        mdelay(1);  /* wait for LPF auto calibration */
        i++;
    }

    /* RCCLKOFF = 1 calibration done, desactivate the calibration Clock */
    priv->regs[RSTV6110_CTRL3] |= (1 << 6);
    stv6110_write_regs(fe, &priv->regs[RSTV6110_CTRL3], RSTV6110_CTRL3, 1);
    return 0;
}

static int stv6110_init(struct dvb_frontend *fe)
{
    struct stv6110_priv *priv = fe->tuner_priv;
    u8 buf0[] = { 0x07, 0x11, 0xdc, 0x85, 0x17, 0x01, 0xe6, 0x1e };

    memcpy(priv->regs, buf0, 8);
    /* K = (Reference / 1000000) - 16 */
    priv->regs[RSTV6110_CTRL1] &= ~(0x1f << 3);
    priv->regs[RSTV6110_CTRL1] |=
                ((((priv->mclk / 1000000) - 16) & 0x1f) << 3);

    /* divisor value for the output clock */
    priv->regs[RSTV6110_CTRL2] &= ~0xc0;
    priv->regs[RSTV6110_CTRL2] |= (priv->clk_div << 6);

    stv6110_write_regs(fe, &priv->regs[RSTV6110_CTRL1], RSTV6110_CTRL1, 8);
    msleep(1);
    stv6110_set_bandwidth(fe, 72000000);

    return 0;
}

static int stv6110_get_frequency(struct dvb_frontend *fe, u32 *frequency)
{
    struct stv6110_priv *priv = fe->tuner_priv;
    u32 nbsteps, divider, psd2, freq;
    u8 regs[] = { 0, 0, 0, 0, 0, 0, 0, 0 };

    stv6110_read_regs(fe, regs, 0, 8);
    /*N*/
    divider = (priv->regs[RSTV6110_TUNING2] & 0x0f) << 8;
    divider += priv->regs[RSTV6110_TUNING1];

    /*R*/
    nbsteps  = (priv->regs[RSTV6110_TUNING2] >> 6) & 3;
    /*p*/
    psd2  = (priv->regs[RSTV6110_TUNING2] >> 4) & 1;

    freq = divider * (priv->mclk / 1000);
    freq /= (1 << (nbsteps + psd2));
    freq /= 4;

    *frequency = freq;

    return 0;
}

static int stv6110_set_frequency(struct dvb_frontend *fe, u32 frequency)
{
    struct stv6110_priv *priv = fe->tuner_priv;
    struct dtv_frontend_properties *c = &fe->dtv_property_cache;
    u8 ret = 0x04;
    u32 divider, ref, p, presc, i, result_freq, vco_freq;
    s32 p_calc, p_calc_opt = 1000, r_div, r_div_opt = 0, p_val;
    s32 srate;

    dprintk("%s, freq=%d kHz, mclk=%d Hz\n", __func__,
                        frequency, priv->mclk);

    /* K = (Reference / 1000000) - 16 */
    priv->regs[RSTV6110_CTRL1] &= ~(0x1f << 3);
    priv->regs[RSTV6110_CTRL1] |=
                ((((priv->mclk / 1000000) - 16) & 0x1f) << 3);

    /* BB_GAIN = db/2 */
    if (fe->ops.set_property && fe->ops.get_property) {
        srate = c->symbol_rate;
        dprintk("%s: Get Frontend parameters: srate=%d\n",
                            __func__, srate);
    } else
        srate = 15000000;

    priv->regs[RSTV6110_CTRL2] &= ~0x0f;
    priv->regs[RSTV6110_CTRL2] |= (priv->gain & 0x0f);

    if (frequency <= 1023000) {
        p = 1;
        presc = 0;
    } else if (frequency <= 1300000) {
        p = 1;
        presc = 1;
    } else if (frequency <= 2046000) {
        p = 0;
        presc = 0;
    } else {
        p = 0;
        presc = 1;
    }
    /* DIV4SEL = p*/
    priv->regs[RSTV6110_TUNING2] &= ~(1 << 4);
    priv->regs[RSTV6110_TUNING2] |= (p << 4);

    /* PRESC32ON = presc */
    priv->regs[RSTV6110_TUNING2] &= ~(1 << 5);
    priv->regs[RSTV6110_TUNING2] |= (presc << 5);

    p_val = (int)(1 << (p + 1)) * 10;/* P = 2 or P = 4 */
    for (r_div = 0; r_div <= 3; r_div++) {
        p_calc = (priv->mclk / 100000);
        p_calc /= (1 << (r_div + 1));
        if ((abssub(p_calc, p_val)) < (abssub(p_calc_opt, p_val)))
            r_div_opt = r_div;

        p_calc_opt = (priv->mclk / 100000);
        p_calc_opt /= (1 << (r_div_opt + 1));
    }

    ref = priv->mclk / ((1 << (r_div_opt + 1))  * (1 << (p + 1)));
    divider = (((frequency * 1000) + (ref >> 1)) / ref);

    /* RDIV = r_div_opt */
    priv->regs[RSTV6110_TUNING2] &= ~(3 << 6);
    priv->regs[RSTV6110_TUNING2] |= (((r_div_opt) & 3) << 6);

    /* NDIV_MSB = MSB(divider) */
    priv->regs[RSTV6110_TUNING2] &= ~0x0f;
    priv->regs[RSTV6110_TUNING2] |= (((divider) >> 8) & 0x0f);

    /* NDIV_LSB, LSB(divider) */
    priv->regs[RSTV6110_TUNING1] = (divider & 0xff);

    /* CALVCOSTRT = 1 VCO Auto Calibration */
    priv->regs[RSTV6110_STAT1] |= 0x04;
    stv6110_write_regs(fe, &priv->regs[RSTV6110_CTRL1],
                        RSTV6110_CTRL1, 8);

    i = 0;
    /* Wait for CALVCOSTRT == 0 */
    while ((i < 10) && (ret != 0)) {
        ret = ((stv6110_read_reg(fe, RSTV6110_STAT1)) & 0x04);
        msleep(1); /* wait for VCO auto calibration */
        i++;
    }

    ret = stv6110_read_reg(fe, RSTV6110_STAT1);
    stv6110_get_frequency(fe, &result_freq);

    vco_freq = divider * ((priv->mclk / 1000) / ((1 << (r_div_opt + 1))));
    dprintk("%s, stat1=%x, lo_freq=%d kHz, vco_frec=%d kHz\n", __func__,
                        ret, result_freq, vco_freq);

    return 0;
}

static int stv6110_set_params(struct dvb_frontend *fe)
{
    struct dtv_frontend_properties *c = &fe->dtv_property_cache;
    u32 bandwidth = carrier_width(c->symbol_rate, c->rolloff);

    stv6110_set_frequency(fe, c->frequency);
    stv6110_set_bandwidth(fe, bandwidth);

    return 0;
}

static int stv6110_get_bandwidth(struct dvb_frontend *fe, u32 *bandwidth)
{
    struct stv6110_priv *priv = fe->tuner_priv;
    u8 r8 = 0;
    u8 regs[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
    stv6110_read_regs(fe, regs, 0, 8);

    /* CF */
    r8 = priv->regs[RSTV6110_CTRL3] & 0x1f;
    *bandwidth = (r8 + 5) * 2000000;/* x2 for ZIF tuner BW/2 = F+5 Mhz */

    return 0;
}

static struct dvb_tuner_ops stv6110_tuner_ops = {
    .info = {
        .name = "ST STV6110",
        .frequency_min = 950000,
        .frequency_max = 2150000,
        .frequency_step = 1000,
    },
    .init = stv6110_init,
    .release = stv6110_release,
    .sleep = stv6110_sleep,
    .set_params = stv6110_set_params,
    .get_frequency = stv6110_get_frequency,
    .set_frequency = stv6110_set_frequency,
    .get_bandwidth = stv6110_get_bandwidth,
    .set_bandwidth = stv6110_set_bandwidth,

};

struct dvb_frontend *stv6110_attach(struct dvb_frontend *fe,
                    const struct stv6110_config *config,
                    struct i2c_adapter *i2c)
{
    struct stv6110_priv *priv = NULL;
    u8 reg0[] = { 0x00, 0x07, 0x11, 0xdc, 0x85, 0x17, 0x01, 0xe6, 0x1e };

    struct i2c_msg msg[] = {
        {
            .addr = config->i2c_address,
            .flags = 0,
            .buf = reg0,
            .len = 9
        }
    };
    int ret;

    /* divisor value for the output clock */
    reg0[2] &= ~0xc0;
    reg0[2] |= (config->clk_div << 6);

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

    ret = i2c_transfer(i2c, msg, 1);

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

    if (ret != 1)
        return NULL;

    priv = kzalloc(sizeof(struct stv6110_priv), GFP_KERNEL);
    if (priv == NULL)
        return NULL;

    priv->i2c_address = config->i2c_address;
    priv->i2c = i2c;
    priv->mclk = config->mclk;
    priv->clk_div = config->clk_div;
    priv->gain = config->gain;

    memcpy(&priv->regs, &reg0[1], 8);

    memcpy(&fe->ops.tuner_ops, &stv6110_tuner_ops,
                sizeof(struct dvb_tuner_ops));
    fe->tuner_priv = priv;
    printk(KERN_INFO "STV6110 attached on addr=%x!\n", priv->i2c_address);

    return fe;
}
EXPORT_SYMBOL(stv6110_attach);

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

MODULE_DESCRIPTION("ST STV6110 driver");
MODULE_AUTHOR("Igor M. Liplianin");
MODULE_LICENSE("GPL");