ec100.c

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/*
 * E3C EC100 demodulator driver
 *
 * Copyright (C) 2009 Antti Palosaari <[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 "dvb_frontend.h"
#include "ec100.h"

struct ec100_state {
    struct i2c_adapter *i2c;
    struct dvb_frontend frontend;
    struct ec100_config config;

    u16 ber;
};

/* write single register */
static int ec100_write_reg(struct ec100_state *state, u8 reg, u8 val)
{
    int ret;
    u8 buf[2] = {reg, val};
    struct i2c_msg msg[1] = {
        {
            .addr = state->config.demod_address,
            .flags = 0,
            .len = sizeof(buf),
            .buf = buf,
        }
    };

    ret = i2c_transfer(state->i2c, msg, 1);
    if (ret == 1) {
        ret = 0;
    } else {
        dev_warn(&state->i2c->dev, "%s: i2c wr failed=%d reg=%02x\n",
                KBUILD_MODNAME, ret, reg);
        ret = -EREMOTEIO;
    }

    return ret;
}

/* read single register */
static int ec100_read_reg(struct ec100_state *state, u8 reg, u8 *val)
{
    int ret;
    struct i2c_msg msg[2] = {
        {
            .addr = state->config.demod_address,
            .flags = 0,
            .len = 1,
            .buf = &reg
        }, {
            .addr = state->config.demod_address,
            .flags = I2C_M_RD,
            .len = 1,
            .buf = val
        }
    };

    ret = i2c_transfer(state->i2c, msg, 2);
    if (ret == 2) {
        ret = 0;
    } else {
        dev_warn(&state->i2c->dev, "%s: i2c rd failed=%d reg=%02x\n",
                KBUILD_MODNAME, ret, reg);
        ret = -EREMOTEIO;
    }

    return ret;
}

static int ec100_set_frontend(struct dvb_frontend *fe)
{
    struct dtv_frontend_properties *c = &fe->dtv_property_cache;
    struct ec100_state *state = fe->demodulator_priv;
    int ret;
    u8 tmp, tmp2;

    dev_dbg(&state->i2c->dev, "%s: frequency=%d bandwidth_hz=%d\n",
            __func__, c->frequency, c->bandwidth_hz);

    /* program tuner */
    if (fe->ops.tuner_ops.set_params)
        fe->ops.tuner_ops.set_params(fe);

    ret = ec100_write_reg(state, 0x04, 0x06);
    if (ret)
        goto error;
    ret = ec100_write_reg(state, 0x67, 0x58);
    if (ret)
        goto error;
    ret = ec100_write_reg(state, 0x05, 0x18);
    if (ret)
        goto error;

    /* reg/bw |   6  |   7  |   8
       -------+------+------+------
       A 0x1b | 0xa1 | 0xe7 | 0x2c
       A 0x1c | 0x55 | 0x63 | 0x72
       -------+------+------+------
       B 0x1b | 0xb7 | 0x00 | 0x49
       B 0x1c | 0x55 | 0x64 | 0x72 */

    switch (c->bandwidth_hz) {
    case 6000000:
        tmp = 0xb7;
        tmp2 = 0x55;
        break;
    case 7000000:
        tmp = 0x00;
        tmp2 = 0x64;
        break;
    case 8000000:
    default:
        tmp = 0x49;
        tmp2 = 0x72;
    }

    ret = ec100_write_reg(state, 0x1b, tmp);
    if (ret)
        goto error;
    ret = ec100_write_reg(state, 0x1c, tmp2);
    if (ret)
        goto error;

    ret = ec100_write_reg(state, 0x0c, 0xbb); /* if freq */
    if (ret)
        goto error;
    ret = ec100_write_reg(state, 0x0d, 0x31); /* if freq */
    if (ret)
        goto error;

    ret = ec100_write_reg(state, 0x08, 0x24);
    if (ret)
        goto error;

    ret = ec100_write_reg(state, 0x00, 0x00); /* go */
    if (ret)
        goto error;
    ret = ec100_write_reg(state, 0x00, 0x20); /* go */
    if (ret)
        goto error;

    return ret;
error:
    dev_dbg(&state->i2c->dev, "%s: failed=%d\n", __func__, ret);
    return ret;
}

static int ec100_get_tune_settings(struct dvb_frontend *fe,
    struct dvb_frontend_tune_settings *fesettings)
{
    fesettings->min_delay_ms = 300;
    fesettings->step_size = 0;
    fesettings->max_drift = 0;

    return 0;
}

static int ec100_read_status(struct dvb_frontend *fe, fe_status_t *status)
{
    struct ec100_state *state = fe->demodulator_priv;
    int ret;
    u8 tmp;
    *status = 0;

    ret = ec100_read_reg(state, 0x42, &tmp);
    if (ret)
        goto error;

    if (tmp & 0x80) {
        /* bit7 set - have lock */
        *status |= FE_HAS_SIGNAL | FE_HAS_CARRIER | FE_HAS_VITERBI |
            FE_HAS_SYNC | FE_HAS_LOCK;
    } else {
        ret = ec100_read_reg(state, 0x01, &tmp);
        if (ret)
            goto error;

        if (tmp & 0x10) {
            /* bit4 set - have signal */
            *status |= FE_HAS_SIGNAL;
            if (!(tmp & 0x01)) {
                /* bit0 clear - have ~valid signal */
                *status |= FE_HAS_CARRIER |  FE_HAS_VITERBI;
            }
        }
    }

    return ret;
error:
    dev_dbg(&state->i2c->dev, "%s: failed=%d\n", __func__, ret);
    return ret;
}

static int ec100_read_ber(struct dvb_frontend *fe, u32 *ber)
{
    struct ec100_state *state = fe->demodulator_priv;
    int ret;
    u8 tmp, tmp2;
    u16 ber2;

    *ber = 0;

    ret = ec100_read_reg(state, 0x65, &tmp);
    if (ret)
        goto error;
    ret = ec100_read_reg(state, 0x66, &tmp2);
    if (ret)
        goto error;

    ber2 = (tmp2 << 8) | tmp;

    /* if counter overflow or clear */
    if (ber2 < state->ber)
        *ber = ber2;
    else
        *ber = ber2 - state->ber;

    state->ber = ber2;

    return ret;
error:
    dev_dbg(&state->i2c->dev, "%s: failed=%d\n", __func__, ret);
    return ret;
}

static int ec100_read_signal_strength(struct dvb_frontend *fe, u16 *strength)
{
    struct ec100_state *state = fe->demodulator_priv;
    int ret;
    u8 tmp;

    ret = ec100_read_reg(state, 0x24, &tmp);
    if (ret) {
        *strength = 0;
        goto error;
    }

    *strength = ((tmp << 8) | tmp);

    return ret;
error:
    dev_dbg(&state->i2c->dev, "%s: failed=%d\n", __func__, ret);
    return ret;
}

static int ec100_read_snr(struct dvb_frontend *fe, u16 *snr)
{
    *snr = 0;
    return 0;
}

static int ec100_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
{
    *ucblocks = 0;
    return 0;
}

static void ec100_release(struct dvb_frontend *fe)
{
    struct ec100_state *state = fe->demodulator_priv;
    kfree(state);
}

static struct dvb_frontend_ops ec100_ops;

struct dvb_frontend *ec100_attach(const struct ec100_config *config,
    struct i2c_adapter *i2c)
{
    int ret;
    struct ec100_state *state = NULL;
    u8 tmp;

    /* allocate memory for the internal state */
    state = kzalloc(sizeof(struct ec100_state), GFP_KERNEL);
    if (state == NULL)
        goto error;

    /* setup the state */
    state->i2c = i2c;
    memcpy(&state->config, config, sizeof(struct ec100_config));

    /* check if the demod is there */
    ret = ec100_read_reg(state, 0x33, &tmp);
    if (ret || tmp != 0x0b)
        goto error;

    /* create dvb_frontend */
    memcpy(&state->frontend.ops, &ec100_ops,
        sizeof(struct dvb_frontend_ops));
    state->frontend.demodulator_priv = state;

    return &state->frontend;
error:
    kfree(state);
    return NULL;
}
EXPORT_SYMBOL(ec100_attach);

static struct dvb_frontend_ops ec100_ops = {
    .delsys = { SYS_DVBT },
    .info = {
        .name = "E3C EC100 DVB-T",
        .caps =
            FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
            FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
            FE_CAN_QPSK | FE_CAN_QAM_16 |
            FE_CAN_QAM_64 | FE_CAN_QAM_AUTO |
            FE_CAN_TRANSMISSION_MODE_AUTO |
            FE_CAN_GUARD_INTERVAL_AUTO |
            FE_CAN_HIERARCHY_AUTO |
            FE_CAN_MUTE_TS
    },

    .release = ec100_release,
    .set_frontend = ec100_set_frontend,
    .get_tune_settings = ec100_get_tune_settings,
    .read_status = ec100_read_status,
    .read_ber = ec100_read_ber,
    .read_signal_strength = ec100_read_signal_strength,
    .read_snr = ec100_read_snr,
    .read_ucblocks = ec100_read_ucblocks,
};

MODULE_AUTHOR("Antti Palosaari <[email protected]>");
MODULE_DESCRIPTION("E3C EC100 DVB-T demodulator driver");
MODULE_LICENSE("GPL");