tua6100.c

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

#include "tua6100.h"

struct tua6100_priv {
    /* i2c details */
    int i2c_address;
    struct i2c_adapter *i2c;
    u32 frequency;
};

static int tua6100_release(struct dvb_frontend *fe)
{
    kfree(fe->tuner_priv);
    fe->tuner_priv = NULL;
    return 0;
}

static int tua6100_sleep(struct dvb_frontend *fe)
{
    struct tua6100_priv *priv = fe->tuner_priv;
    int ret;
    u8 reg0[] = { 0x00, 0x00 };
    struct i2c_msg msg = { .addr = priv->i2c_address, .flags = 0, .buf = reg0, .len = 2 };

    if (fe->ops.i2c_gate_ctrl)
        fe->ops.i2c_gate_ctrl(fe, 1);
    if ((ret = i2c_transfer (priv->i2c, &msg, 1)) != 1) {
        printk("%s: i2c error\n", __func__);
    }
    if (fe->ops.i2c_gate_ctrl)
        fe->ops.i2c_gate_ctrl(fe, 0);

    return (ret == 1) ? 0 : ret;
}

static int tua6100_set_params(struct dvb_frontend *fe)
{
    struct dtv_frontend_properties *c = &fe->dtv_property_cache;
    struct tua6100_priv *priv = fe->tuner_priv;
    u32 div;
    u32 prediv;
    u8 reg0[] = { 0x00, 0x00 };
    u8 reg1[] = { 0x01, 0x00, 0x00, 0x00 };
    u8 reg2[] = { 0x02, 0x00, 0x00 };
    struct i2c_msg msg0 = { .addr = priv->i2c_address, .flags = 0, .buf = reg0, .len = 2 };
    struct i2c_msg msg1 = { .addr = priv->i2c_address, .flags = 0, .buf = reg1, .len = 4 };
    struct i2c_msg msg2 = { .addr = priv->i2c_address, .flags = 0, .buf = reg2, .len = 3 };

#define _R 4
#define _P 32
#define _ri 4000000

    // setup register 0
    if (c->frequency < 2000000)
        reg0[1] = 0x03;
    else
        reg0[1] = 0x07;

    // setup register 1
    if (c->frequency < 1630000)
        reg1[1] = 0x2c;
    else
        reg1[1] = 0x0c;

    if (_P == 64)
        reg1[1] |= 0x40;
    if (c->frequency >= 1525000)
        reg1[1] |= 0x80;

    // register 2
    reg2[1] = (_R >> 8) & 0x03;
    reg2[2] = _R;
    if (c->frequency < 1455000)
        reg2[1] |= 0x1c;
    else if (c->frequency < 1630000)
        reg2[1] |= 0x0c;
    else
        reg2[1] |= 0x1c;

    /*
     * The N divisor ratio (note: c->frequency is in kHz, but we
     * need it in Hz)
     */
    prediv = (c->frequency * _R) / (_ri / 1000);
    div = prediv / _P;
    reg1[1] |= (div >> 9) & 0x03;
    reg1[2] = div >> 1;
    reg1[3] = (div << 7);
    priv->frequency = ((div * _P) * (_ri / 1000)) / _R;

    // Finally, calculate and store the value for A
    reg1[3] |= (prediv - (div*_P)) & 0x7f;

#undef _R
#undef _P
#undef _ri

    if (fe->ops.i2c_gate_ctrl)
        fe->ops.i2c_gate_ctrl(fe, 1);
    if (i2c_transfer(priv->i2c, &msg0, 1) != 1)
        return -EIO;

    if (fe->ops.i2c_gate_ctrl)
        fe->ops.i2c_gate_ctrl(fe, 1);
    if (i2c_transfer(priv->i2c, &msg2, 1) != 1)
        return -EIO;

    if (fe->ops.i2c_gate_ctrl)
        fe->ops.i2c_gate_ctrl(fe, 1);
    if (i2c_transfer(priv->i2c, &msg1, 1) != 1)
        return -EIO;

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

    return 0;
}

static int tua6100_get_frequency(struct dvb_frontend *fe, u32 *frequency)
{
    struct tua6100_priv *priv = fe->tuner_priv;
    *frequency = priv->frequency;
    return 0;
}

static struct dvb_tuner_ops tua6100_tuner_ops = {
    .info = {
        .name = "Infineon TUA6100",
        .frequency_min = 950000,
        .frequency_max = 2150000,
        .frequency_step = 1000,
    },
    .release = tua6100_release,
    .sleep = tua6100_sleep,
    .set_params = tua6100_set_params,
    .get_frequency = tua6100_get_frequency,
};

struct dvb_frontend *tua6100_attach(struct dvb_frontend *fe, int addr, struct i2c_adapter *i2c)
{
    struct tua6100_priv *priv = NULL;
    u8 b1 [] = { 0x80 };
    u8 b2 [] = { 0x00 };
    struct i2c_msg msg [] = { { .addr = addr, .flags = 0, .buf = b1, .len = 1 },
                  { .addr = addr, .flags = I2C_M_RD, .buf = b2, .len = 1 } };
    int ret;

    if (fe->ops.i2c_gate_ctrl)
        fe->ops.i2c_gate_ctrl(fe, 1);
    ret = i2c_transfer (i2c, msg, 2);
    if (fe->ops.i2c_gate_ctrl)
        fe->ops.i2c_gate_ctrl(fe, 0);

    if (ret != 2)
        return NULL;

    priv = kzalloc(sizeof(struct tua6100_priv), GFP_KERNEL);
    if (priv == NULL)
        return NULL;

    priv->i2c_address = addr;
    priv->i2c = i2c;

    memcpy(&fe->ops.tuner_ops, &tua6100_tuner_ops, sizeof(struct dvb_tuner_ops));
    fe->tuner_priv = priv;
    return fe;
}
EXPORT_SYMBOL(tua6100_attach);

MODULE_DESCRIPTION("DVB tua6100 driver");
MODULE_AUTHOR("Andrew de Quincey");
MODULE_LICENSE("GPL");