atbm8830.c

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/*
 *    Support for AltoBeam GB20600 (a.k.a DMB-TH) demodulator
 *    ATBM8830, ATBM8831
 *
 *    Copyright (C) 2009 David T.L. Wong <[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 <asm/div64.h>
#include "dvb_frontend.h"

#include "atbm8830.h"
#include "atbm8830_priv.h"

#define dprintk(args...) \
    do { \
        if (debug) \
            printk(KERN_DEBUG "atbm8830: " args); \
    } while (0)

static int debug;

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

static int atbm8830_write_reg(struct atbm_state *priv, u16 reg, u8 data)
{
    int ret = 0;
    u8 dev_addr;
    u8 buf1[] = { reg >> 8, reg & 0xFF };
    u8 buf2[] = { data };
    struct i2c_msg msg1 = { .flags = 0, .buf = buf1, .len = 2 };
    struct i2c_msg msg2 = { .flags = 0, .buf = buf2, .len = 1 };

    dev_addr = priv->config->demod_address;
    msg1.addr = dev_addr;
    msg2.addr = dev_addr;

    if (debug >= 2)
        dprintk("%s: reg=0x%04X, data=0x%02X\n", __func__, reg, data);

    ret = i2c_transfer(priv->i2c, &msg1, 1);
    if (ret != 1)
        return -EIO;

    ret = i2c_transfer(priv->i2c, &msg2, 1);
    return (ret != 1) ? -EIO : 0;
}

static int atbm8830_read_reg(struct atbm_state *priv, u16 reg, u8 *p_data)
{
    int ret;
    u8 dev_addr;

    u8 buf1[] = { reg >> 8, reg & 0xFF };
    u8 buf2[] = { 0 };
    struct i2c_msg msg1 = { .flags = 0, .buf = buf1, .len = 2 };
    struct i2c_msg msg2 = { .flags = I2C_M_RD, .buf = buf2, .len = 1 };

    dev_addr = priv->config->demod_address;
    msg1.addr = dev_addr;
    msg2.addr = dev_addr;

    ret = i2c_transfer(priv->i2c, &msg1, 1);
    if (ret != 1) {
        dprintk("%s: error reg=0x%04x, ret=%i\n", __func__, reg, ret);
        return -EIO;
    }

    ret = i2c_transfer(priv->i2c, &msg2, 1);
    if (ret != 1)
        return -EIO;

    *p_data = buf2[0];
    if (debug >= 2)
        dprintk("%s: reg=0x%04X, data=0x%02X\n",
            __func__, reg, buf2[0]);

    return 0;
}

/* Lock register latch so that multi-register read is atomic */
static inline int atbm8830_reglatch_lock(struct atbm_state *priv, int lock)
{
    return atbm8830_write_reg(priv, REG_READ_LATCH, lock ? 1 : 0);
}

static int set_osc_freq(struct atbm_state *priv, u32 freq /*in kHz*/)
{
    u32 val;
    u64 t;

    /* 0x100000 * freq / 30.4MHz */
    t = (u64)0x100000 * freq;
    do_div(t, 30400);
    val = t;

    atbm8830_write_reg(priv, REG_OSC_CLK, val);
    atbm8830_write_reg(priv, REG_OSC_CLK + 1, val >> 8);
    atbm8830_write_reg(priv, REG_OSC_CLK + 2, val >> 16);

    return 0;
}

static int set_if_freq(struct atbm_state *priv, u32 freq /*in kHz*/)
{

    u32 fs = priv->config->osc_clk_freq;
    u64 t;
    u32 val;
    u8 dat;

    if (freq != 0) {
        /* 2 * PI * (freq - fs) / fs * (2 ^ 22) */
        t = (u64) 2 * 31416 * (freq - fs);
        t <<= 22;
        do_div(t, fs);
        do_div(t, 1000);
        val = t;

        atbm8830_write_reg(priv, REG_TUNER_BASEBAND, 1);
        atbm8830_write_reg(priv, REG_IF_FREQ, val);
        atbm8830_write_reg(priv, REG_IF_FREQ+1, val >> 8);
        atbm8830_write_reg(priv, REG_IF_FREQ+2, val >> 16);

        atbm8830_read_reg(priv, REG_ADC_CONFIG, &dat);
        dat &= 0xFC;
        atbm8830_write_reg(priv, REG_ADC_CONFIG, dat);
    } else {
        /* Zero IF */
        atbm8830_write_reg(priv, REG_TUNER_BASEBAND, 0);

        atbm8830_read_reg(priv, REG_ADC_CONFIG, &dat);
        dat &= 0xFC;
        dat |= 0x02;
        atbm8830_write_reg(priv, REG_ADC_CONFIG, dat);

        if (priv->config->zif_swap_iq)
            atbm8830_write_reg(priv, REG_SWAP_I_Q, 0x03);
        else
            atbm8830_write_reg(priv, REG_SWAP_I_Q, 0x01);
    }

    return 0;
}

static int is_locked(struct atbm_state *priv, u8 *locked)
{
    u8 status;

    atbm8830_read_reg(priv, REG_LOCK_STATUS, &status);

    if (locked != NULL)
        *locked = (status == 1);
    return 0;
}

static int set_agc_config(struct atbm_state *priv,
    u8 min, u8 max, u8 hold_loop)
{
    /* no effect if both min and max are zero */
    if (!min && !max)
        return 0;

    atbm8830_write_reg(priv, REG_AGC_MIN, min);
    atbm8830_write_reg(priv, REG_AGC_MAX, max);
    atbm8830_write_reg(priv, REG_AGC_HOLD_LOOP, hold_loop);

    return 0;
}

static int set_static_channel_mode(struct atbm_state *priv)
{
    int i;

    for (i = 0; i < 5; i++)
        atbm8830_write_reg(priv, 0x099B + i, 0x08);

    atbm8830_write_reg(priv, 0x095B, 0x7F);
    atbm8830_write_reg(priv, 0x09CB, 0x01);
    atbm8830_write_reg(priv, 0x09CC, 0x7F);
    atbm8830_write_reg(priv, 0x09CD, 0x7F);
    atbm8830_write_reg(priv, 0x0E01, 0x20);

    /* For single carrier */
    atbm8830_write_reg(priv, 0x0B03, 0x0A);
    atbm8830_write_reg(priv, 0x0935, 0x10);
    atbm8830_write_reg(priv, 0x0936, 0x08);
    atbm8830_write_reg(priv, 0x093E, 0x08);
    atbm8830_write_reg(priv, 0x096E, 0x06);

    /* frame_count_max0 */
    atbm8830_write_reg(priv, 0x0B09, 0x00);
    /* frame_count_max1 */
    atbm8830_write_reg(priv, 0x0B0A, 0x08);

    return 0;
}

static int set_ts_config(struct atbm_state *priv)
{
    const struct atbm8830_config *cfg = priv->config;

    /*Set parallel/serial ts mode*/
    atbm8830_write_reg(priv, REG_TS_SERIAL, cfg->serial_ts ? 1 : 0);
    atbm8830_write_reg(priv, REG_TS_CLK_MODE, cfg->serial_ts ? 1 : 0);
    /*Set ts sampling edge*/
    atbm8830_write_reg(priv, REG_TS_SAMPLE_EDGE,
        cfg->ts_sampling_edge ? 1 : 0);
    /*Set ts clock freerun*/
    atbm8830_write_reg(priv, REG_TS_CLK_FREERUN,
        cfg->ts_clk_gated ? 0 : 1);

    return 0;
}

static int atbm8830_init(struct dvb_frontend *fe)
{
    struct atbm_state *priv = fe->demodulator_priv;
    const struct atbm8830_config *cfg = priv->config;

    /*Set oscillator frequency*/
    set_osc_freq(priv, cfg->osc_clk_freq);

    /*Set IF frequency*/
    set_if_freq(priv, cfg->if_freq);

    /*Set AGC Config*/
    set_agc_config(priv, cfg->agc_min, cfg->agc_max,
        cfg->agc_hold_loop);

    /*Set static channel mode*/
    set_static_channel_mode(priv);

    set_ts_config(priv);
    /*Turn off DSP reset*/
    atbm8830_write_reg(priv, 0x000A, 0);

    /*SW version test*/
    atbm8830_write_reg(priv, 0x020C, 11);

    /* Run */
    atbm8830_write_reg(priv, REG_DEMOD_RUN, 1);

    return 0;
}


static void atbm8830_release(struct dvb_frontend *fe)
{
    struct atbm_state *state = fe->demodulator_priv;
    dprintk("%s\n", __func__);

    kfree(state);
}

static int atbm8830_set_fe(struct dvb_frontend *fe)
{
    struct atbm_state *priv = fe->demodulator_priv;
    int i;
    u8 locked = 0;
    dprintk("%s\n", __func__);

    /* set frequency */
    if (fe->ops.tuner_ops.set_params) {
        if (fe->ops.i2c_gate_ctrl)
            fe->ops.i2c_gate_ctrl(fe, 1);
        fe->ops.tuner_ops.set_params(fe);
        if (fe->ops.i2c_gate_ctrl)
            fe->ops.i2c_gate_ctrl(fe, 0);
    }

    /* start auto lock */
    for (i = 0; i < 10; i++) {
        mdelay(100);
        dprintk("Try %d\n", i);
        is_locked(priv, &locked);
        if (locked != 0) {
            dprintk("ATBM8830 locked!\n");
            break;
        }
    }

    return 0;
}

static int atbm8830_get_fe(struct dvb_frontend *fe)
{
    struct dtv_frontend_properties *c = &fe->dtv_property_cache;
    dprintk("%s\n", __func__);

    /* TODO: get real readings from device */
    /* inversion status */
    c->inversion = INVERSION_OFF;

    /* bandwidth */
    c->bandwidth_hz = 8000000;

    c->code_rate_HP = FEC_AUTO;
    c->code_rate_LP = FEC_AUTO;

    c->modulation = QAM_AUTO;

    /* transmission mode */
    c->transmission_mode = TRANSMISSION_MODE_AUTO;

    /* guard interval */
    c->guard_interval = GUARD_INTERVAL_AUTO;

    /* hierarchy */
    c->hierarchy = HIERARCHY_NONE;

    return 0;
}

static int atbm8830_get_tune_settings(struct dvb_frontend *fe,
    struct dvb_frontend_tune_settings *fesettings)
{
    fesettings->min_delay_ms = 0;
    fesettings->step_size = 0;
    fesettings->max_drift = 0;
    return 0;
}

static int atbm8830_read_status(struct dvb_frontend *fe, fe_status_t *fe_status)
{
    struct atbm_state *priv = fe->demodulator_priv;
    u8 locked = 0;
    u8 agc_locked = 0;

    dprintk("%s\n", __func__);
    *fe_status = 0;

    is_locked(priv, &locked);
    if (locked) {
        *fe_status |= FE_HAS_SIGNAL | FE_HAS_CARRIER |
            FE_HAS_VITERBI | FE_HAS_SYNC | FE_HAS_LOCK;
    }
    dprintk("%s: fe_status=0x%x\n", __func__, *fe_status);

    atbm8830_read_reg(priv, REG_AGC_LOCK, &agc_locked);
    dprintk("AGC Lock: %d\n", agc_locked);

    return 0;
}

static int atbm8830_read_ber(struct dvb_frontend *fe, u32 *ber)
{
    struct atbm_state *priv = fe->demodulator_priv;
    u32 frame_err;
    u8 t;

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

    atbm8830_reglatch_lock(priv, 1);

    atbm8830_read_reg(priv, REG_FRAME_ERR_CNT + 1, &t);
    frame_err = t & 0x7F;
    frame_err <<= 8;
    atbm8830_read_reg(priv, REG_FRAME_ERR_CNT, &t);
    frame_err |= t;

    atbm8830_reglatch_lock(priv, 0);

    *ber = frame_err * 100 / 32767;

    dprintk("%s: ber=0x%x\n", __func__, *ber);
    return 0;
}

static int atbm8830_read_signal_strength(struct dvb_frontend *fe, u16 *signal)
{
    struct atbm_state *priv = fe->demodulator_priv;
    u32 pwm;
    u8 t;

    dprintk("%s\n", __func__);
    atbm8830_reglatch_lock(priv, 1);

    atbm8830_read_reg(priv, REG_AGC_PWM_VAL + 1, &t);
    pwm = t & 0x03;
    pwm <<= 8;
    atbm8830_read_reg(priv, REG_AGC_PWM_VAL, &t);
    pwm |= t;

    atbm8830_reglatch_lock(priv, 0);

    dprintk("AGC PWM = 0x%02X\n", pwm);
    pwm = 0x400 - pwm;

    *signal = pwm * 0x10000 / 0x400;

    return 0;
}

static int atbm8830_read_snr(struct dvb_frontend *fe, u16 *snr)
{
    dprintk("%s\n", __func__);
    *snr = 0;
    return 0;
}

static int atbm8830_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
{
    dprintk("%s\n", __func__);
    *ucblocks = 0;
    return 0;
}

static int atbm8830_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
{
    struct atbm_state *priv = fe->demodulator_priv;

    return atbm8830_write_reg(priv, REG_I2C_GATE, enable ? 1 : 0);
}

static struct dvb_frontend_ops atbm8830_ops = {
    .delsys = { SYS_DTMB },
    .info = {
        .name = "AltoBeam ATBM8830/8831 DMB-TH",
        .frequency_min = 474000000,
        .frequency_max = 858000000,
        .frequency_stepsize = 10000,
        .caps =
            FE_CAN_FEC_AUTO |
            FE_CAN_QAM_AUTO |
            FE_CAN_TRANSMISSION_MODE_AUTO |
            FE_CAN_GUARD_INTERVAL_AUTO
    },

    .release = atbm8830_release,

    .init = atbm8830_init,
    .sleep = NULL,
    .write = NULL,
    .i2c_gate_ctrl = atbm8830_i2c_gate_ctrl,

    .set_frontend = atbm8830_set_fe,
    .get_frontend = atbm8830_get_fe,
    .get_tune_settings = atbm8830_get_tune_settings,

    .read_status = atbm8830_read_status,
    .read_ber = atbm8830_read_ber,
    .read_signal_strength = atbm8830_read_signal_strength,
    .read_snr = atbm8830_read_snr,
    .read_ucblocks = atbm8830_read_ucblocks,
};

struct dvb_frontend *atbm8830_attach(const struct atbm8830_config *config,
    struct i2c_adapter *i2c)
{
    struct atbm_state *priv = NULL;
    u8 data = 0;

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

    if (config == NULL || i2c == NULL)
        return NULL;

    priv = kzalloc(sizeof(struct atbm_state), GFP_KERNEL);
    if (priv == NULL)
        goto error_out;

    priv->config = config;
    priv->i2c = i2c;

    /* check if the demod is there */
    if (atbm8830_read_reg(priv, REG_CHIP_ID, &data) != 0) {
        dprintk("%s atbm8830/8831 not found at i2c addr 0x%02X\n",
            __func__, priv->config->demod_address);
        goto error_out;
    }
    dprintk("atbm8830 chip id: 0x%02X\n", data);

    memcpy(&priv->frontend.ops, &atbm8830_ops,
           sizeof(struct dvb_frontend_ops));
    priv->frontend.demodulator_priv = priv;

    atbm8830_init(&priv->frontend);

    atbm8830_i2c_gate_ctrl(&priv->frontend, 1);

    return &priv->frontend;

error_out:
    dprintk("%s() error_out\n", __func__);
    kfree(priv);
    return NULL;

}
EXPORT_SYMBOL(atbm8830_attach);

MODULE_DESCRIPTION("AltoBeam ATBM8830/8831 GB20600 demodulator driver");
MODULE_AUTHOR("David T. L. Wong <[email protected]>");
MODULE_LICENSE("GPL");