/*
 * Driver for Infineon tua6100 pll.
 *
 * (c) 2006 Andrew de Quincey
 *
 * Based on code found in budget-av.c, which has the following:
 * Compiled from various sources by Michael Hunold <michael@mihu.de>
 *
 * CI interface support (c) 2004 Olivier Gournet <ogournet@anevia.com> &
 *                               Andrew de Quincey <adq_dvb@lidskialf.net>
 *
 * Copyright (C) 2002 Ralph Metzler <rjkm@metzlerbros.de>
 *
 * Copyright (C) 1999-2002 Ralph  Metzler
 *                       & Marcus Metzler for convergence integrated media GmbH
 * 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.
 */

#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 void tua6100_release(struct dvb_frontend *fe)
{
        kfree(fe->tuner_priv);
        fe->tuner_priv = NULL;
}

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 const 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");