tda8261.c

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/*
    TDA8261 8PSK/QPSK tuner driver
    Copyright (C) Manu Abraham ([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/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>

#include "dvb_frontend.h"
#include "tda8261.h"

struct tda8261_state {
    struct dvb_frontend     *fe;
    struct i2c_adapter      *i2c;
    const struct tda8261_config *config;

    /* state cache */
    u32 frequency;
    u32 bandwidth;
};

static int tda8261_read(struct tda8261_state *state, u8 *buf)
{
    const struct tda8261_config *config = state->config;
    int err = 0;
    struct i2c_msg msg = { .addr    = config->addr, .flags = I2C_M_RD,.buf = buf,  .len = 1 };

    if ((err = i2c_transfer(state->i2c, &msg, 1)) != 1)
        pr_err("%s: read error, err=%d\n", __func__, err);

    return err;
}

static int tda8261_write(struct tda8261_state *state, u8 *buf)
{
    const struct tda8261_config *config = state->config;
    int err = 0;
    struct i2c_msg msg = { .addr = config->addr, .flags = 0, .buf = buf, .len = 4 };

    if ((err = i2c_transfer(state->i2c, &msg, 1)) != 1)
        pr_err("%s: write error, err=%d\n", __func__, err);

    return err;
}

static int tda8261_get_status(struct dvb_frontend *fe, u32 *status)
{
    struct tda8261_state *state = fe->tuner_priv;
    u8 result = 0;
    int err = 0;

    *status = 0;

    if ((err = tda8261_read(state, &result)) < 0) {
        pr_err("%s: I/O Error\n", __func__);
        return err;
    }
    if ((result >> 6) & 0x01) {
        pr_debug("%s: Tuner Phase Locked\n", __func__);
        *status = 1;
    }

    return err;
}

static const u32 div_tab[] = { 2000, 1000,  500,  250,  125 }; /* kHz */
static const u8  ref_div[] = { 0x00, 0x01, 0x02, 0x05, 0x07 };

static int tda8261_get_state(struct dvb_frontend *fe,
                 enum tuner_param param,
                 struct tuner_state *tstate)
{
    struct tda8261_state *state = fe->tuner_priv;
    int err = 0;

    switch (param) {
    case DVBFE_TUNER_FREQUENCY:
        tstate->frequency = state->frequency;
        break;
    case DVBFE_TUNER_BANDWIDTH:
        tstate->bandwidth = 40000000; /* FIXME! need to calculate Bandwidth */
        break;
    default:
        pr_err("%s: Unknown parameter (param=%d)\n", __func__, param);
        err = -EINVAL;
        break;
    }

    return err;
}

static int tda8261_set_state(struct dvb_frontend *fe,
                 enum tuner_param param,
                 struct tuner_state *tstate)
{
    struct tda8261_state *state = fe->tuner_priv;
    const struct tda8261_config *config = state->config;
    u32 frequency, N, status = 0;
    u8 buf[4];
    int err = 0;

    if (param & DVBFE_TUNER_FREQUENCY) {
        frequency = tstate->frequency;
        if ((frequency < 950000) || (frequency > 2150000)) {
            pr_warn("%s: Frequency beyond limits, frequency=%d\n", __func__, frequency);
            return -EINVAL;
        }
        N = (frequency + (div_tab[config->step_size] - 1)) / div_tab[config->step_size];
        pr_debug("%s: Step size=%d, Divider=%d, PG=0x%02x (%d)\n",
            __func__, config->step_size, div_tab[config->step_size], N, N);

        buf[0] = (N >> 8) & 0xff;
        buf[1] = N & 0xff;
        buf[2] = (0x01 << 7) | ((ref_div[config->step_size] & 0x07) << 1);

        if (frequency < 1450000)
            buf[3] = 0x00;
        else if (frequency < 2000000)
            buf[3] = 0x40;
        else if (frequency < 2150000)
            buf[3] = 0x80;

        /* Set params */
        if ((err = tda8261_write(state, buf)) < 0) {
            pr_err("%s: I/O Error\n", __func__);
            return err;
        }
        /* sleep for some time */
        pr_debug("%s: Waiting to Phase LOCK\n", __func__);
        msleep(20);
        /* check status */
        if ((err = tda8261_get_status(fe, &status)) < 0) {
            pr_err("%s: I/O Error\n", __func__);
            return err;
        }
        if (status == 1) {
            pr_debug("%s: Tuner Phase locked: status=%d\n", __func__, status);
            state->frequency = frequency; /* cache successful state */
        } else {
            pr_debug("%s: No Phase lock: status=%d\n", __func__, status);
        }
    } else {
        pr_err("%s: Unknown parameter (param=%d)\n", __func__, param);
        return -EINVAL;
    }

    return 0;
}

static int tda8261_release(struct dvb_frontend *fe)
{
    struct tda8261_state *state = fe->tuner_priv;

    fe->tuner_priv = NULL;
    kfree(state);
    return 0;
}

static struct dvb_tuner_ops tda8261_ops = {

    .info = {
        .name       = "TDA8261",
//      .tuner_name = NULL,
        .frequency_min  =  950000,
        .frequency_max  = 2150000,
        .frequency_step = 0
    },

    .set_state  = tda8261_set_state,
    .get_state  = tda8261_get_state,
    .get_status = tda8261_get_status,
    .release    = tda8261_release
};

struct dvb_frontend *tda8261_attach(struct dvb_frontend *fe,
                    const struct tda8261_config *config,
                    struct i2c_adapter *i2c)
{
    struct tda8261_state *state = NULL;

    if ((state = kzalloc(sizeof (struct tda8261_state), GFP_KERNEL)) == NULL)
        goto exit;

    state->config       = config;
    state->i2c      = i2c;
    state->fe       = fe;
    fe->tuner_priv      = state;
    fe->ops.tuner_ops   = tda8261_ops;

    fe->ops.tuner_ops.info.frequency_step = div_tab[config->step_size];
//  fe->ops.tuner_ops.tuner_name     = &config->buf;

//  printk("%s: Attaching %s TDA8261 8PSK/QPSK tuner\n",
//      __func__, fe->ops.tuner_ops.tuner_name);
    pr_info("%s: Attaching TDA8261 8PSK/QPSK tuner\n", __func__);

    return fe;

exit:
    kfree(state);
    return NULL;
}

EXPORT_SYMBOL(tda8261_attach);

MODULE_AUTHOR("Manu Abraham");
MODULE_DESCRIPTION("TDA8261 8PSK/QPSK Tuner");
MODULE_LICENSE("GPL");