tda665x.c

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/*
    TDA665x 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 "tda665x.h"

struct tda665x_state {
    struct dvb_frontend     *fe;
    struct i2c_adapter      *i2c;
    const struct tda665x_config *config;

    u32 frequency;
    u32 bandwidth;
};

static int tda665x_read(struct tda665x_state *state, u8 *buf)
{
    const struct tda665x_config *config = state->config;
    int err = 0;
    struct i2c_msg msg = { .addr = config->addr, .flags = I2C_M_RD, .buf = buf, .len = 2 };

    err = i2c_transfer(state->i2c, &msg, 1);
    if (err != 1)
        goto exit;

    return err;
exit:
    printk(KERN_ERR "%s: I/O Error err=<%d>\n", __func__, err);
    return err;
}

static int tda665x_write(struct tda665x_state *state, u8 *buf, u8 length)
{
    const struct tda665x_config *config = state->config;
    int err = 0;
    struct i2c_msg msg = { .addr = config->addr, .flags = 0, .buf = buf, .len = length };

    err = i2c_transfer(state->i2c, &msg, 1);
    if (err != 1)
        goto exit;

    return err;
exit:
    printk(KERN_ERR "%s: I/O Error err=<%d>\n", __func__, err);
    return err;
}

static int tda665x_get_state(struct dvb_frontend *fe,
                 enum tuner_param param,
                 struct tuner_state *tstate)
{
    struct tda665x_state *state = fe->tuner_priv;
    int err = 0;

    switch (param) {
    case DVBFE_TUNER_FREQUENCY:
        tstate->frequency = state->frequency;
        break;
    case DVBFE_TUNER_BANDWIDTH:
        break;
    default:
        printk(KERN_ERR "%s: Unknown parameter (param=%d)\n", __func__, param);
        err = -EINVAL;
        break;
    }

    return err;
}

static int tda665x_get_status(struct dvb_frontend *fe, u32 *status)
{
    struct tda665x_state *state = fe->tuner_priv;
    u8 result = 0;
    int err = 0;

    *status = 0;

    err = tda665x_read(state, &result);
    if (err < 0)
        goto exit;

    if ((result >> 6) & 0x01) {
        printk(KERN_DEBUG "%s: Tuner Phase Locked\n", __func__);
        *status = 1;
    }

    return err;
exit:
    printk(KERN_ERR "%s: I/O Error\n", __func__);
    return err;
}

static int tda665x_set_state(struct dvb_frontend *fe,
                 enum tuner_param param,
                 struct tuner_state *tstate)
{
    struct tda665x_state *state = fe->tuner_priv;
    const struct tda665x_config *config = state->config;
    u32 frequency, status = 0;
    u8 buf[4];
    int err = 0;

    if (param & DVBFE_TUNER_FREQUENCY) {

        frequency = tstate->frequency;
        if ((frequency < config->frequency_max) || (frequency > config->frequency_min)) {
            printk(KERN_ERR "%s: Frequency beyond limits, frequency=%d\n", __func__, frequency);
            return -EINVAL;
        }

        frequency += config->frequency_offst;
        frequency *= config->ref_multiplier;
        frequency += config->ref_divider >> 1;
        frequency /= config->ref_divider;

        buf[0] = (u8) ((frequency & 0x7f00) >> 8);
        buf[1] = (u8) (frequency & 0x00ff) >> 0;
        buf[2] = 0x80 | 0x40 | 0x02;
        buf[3] = 0x00;

        /* restore frequency */
        frequency = tstate->frequency;

        if (frequency < 153000000) {
            /* VHF-L */
            buf[3] |= 0x01; /* fc, Low Band, 47 - 153 MHz */
            if (frequency < 68000000)
                buf[3] |= 0x40; /* 83uA */
            if (frequency < 1040000000)
                buf[3] |= 0x60; /* 122uA */
            if (frequency < 1250000000)
                buf[3] |= 0x80; /* 163uA */
            else
                buf[3] |= 0xa0; /* 254uA */
        } else if (frequency < 438000000) {
            /* VHF-H */
            buf[3] |= 0x02; /* fc, Mid Band, 153 - 438 MHz */
            if (frequency < 230000000)
                buf[3] |= 0x40;
            if (frequency < 300000000)
                buf[3] |= 0x60;
            else
                buf[3] |= 0x80;
        } else {
            /* UHF */
            buf[3] |= 0x04; /* fc, High Band, 438 - 862 MHz */
            if (frequency < 470000000)
                buf[3] |= 0x60;
            if (frequency < 526000000)
                buf[3] |= 0x80;
            else
                buf[3] |= 0xa0;
        }

        /* Set params */
        err = tda665x_write(state, buf, 5);
        if (err < 0)
            goto exit;

        /* sleep for some time */
        printk(KERN_DEBUG "%s: Waiting to Phase LOCK\n", __func__);
        msleep(20);
        /* check status */
        err = tda665x_get_status(fe, &status);
        if (err < 0)
            goto exit;

        if (status == 1) {
            printk(KERN_DEBUG "%s: Tuner Phase locked: status=%d\n", __func__, status);
            state->frequency = frequency; /* cache successful state */
        } else {
            printk(KERN_ERR "%s: No Phase lock: status=%d\n", __func__, status);
        }
    } else {
        printk(KERN_ERR "%s: Unknown parameter (param=%d)\n", __func__, param);
        return -EINVAL;
    }

    return 0;
exit:
    printk(KERN_ERR "%s: I/O Error\n", __func__);
    return err;
}

static int tda665x_release(struct dvb_frontend *fe)
{
    struct tda665x_state *state = fe->tuner_priv;

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

static struct dvb_tuner_ops tda665x_ops = {

    .set_state  = tda665x_set_state,
    .get_state  = tda665x_get_state,
    .get_status = tda665x_get_status,
    .release    = tda665x_release
};

struct dvb_frontend *tda665x_attach(struct dvb_frontend *fe,
                    const struct tda665x_config *config,
                    struct i2c_adapter *i2c)
{
    struct tda665x_state *state = NULL;
    struct dvb_tuner_info *info;

    state = kzalloc(sizeof(struct tda665x_state), GFP_KERNEL);
    if (!state)
        return NULL;

    state->config       = config;
    state->i2c      = i2c;
    state->fe       = fe;
    fe->tuner_priv      = state;
    fe->ops.tuner_ops   = tda665x_ops;
    info             = &fe->ops.tuner_ops.info;

    memcpy(info->name, config->name, sizeof(config->name));
    info->frequency_min = config->frequency_min;
    info->frequency_max = config->frequency_max;
    info->frequency_step    = config->frequency_offst;

    printk(KERN_DEBUG "%s: Attaching TDA665x (%s) tuner\n", __func__, info->name);

    return fe;
}
EXPORT_SYMBOL(tda665x_attach);

MODULE_DESCRIPTION("TDA665x driver");
MODULE_AUTHOR("Manu Abraham");
MODULE_LICENSE("GPL");