/*
    TDA10021  - Single Chip Cable Channel Receiver driver module
               used on the Siemens DVB-C cards

    Copyright (C) 1999 Convergence Integrated Media GmbH <ralph@convergence.de>
    Copyright (C) 2004 Markus Schulz <msc@antzsystem.de>
                   Support for TDA10021

    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/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/slab.h>

#include "dvb_frontend.h"
#include "tda1002x.h"


struct tda10021_state {
        struct i2c_adapter* i2c;
        /* configuration settings */
        const struct tda1002x_config* config;
        struct dvb_frontend frontend;

        u8 pwm;
        u8 reg0;
};


#if 0
#define dprintk(x...) printk(x)
#else
#define dprintk(x...)
#endif

static int verbose;

#define XIN 57840000UL

#define FIN (XIN >> 4)

static int tda10021_inittab_size = 0x40;
static u8 tda10021_inittab[0x40]=
{
        0x73, 0x6a, 0x23, 0x0a, 0x02, 0x37, 0x77, 0x1a,
        0x37, 0x6a, 0x17, 0x8a, 0x1e, 0x86, 0x43, 0x40,
        0xb8, 0x3f, 0xa1, 0x00, 0xcd, 0x01, 0x00, 0xff,
        0x11, 0x00, 0x7c, 0x31, 0x30, 0x20, 0x00, 0x00,
        0x02, 0x00, 0x00, 0x7d, 0x00, 0x00, 0x00, 0x00,
        0x07, 0x00, 0x33, 0x11, 0x0d, 0x95, 0x08, 0x58,
        0x00, 0x00, 0x80, 0x00, 0x80, 0xff, 0x00, 0x00,
        0x04, 0x2d, 0x2f, 0xff, 0x00, 0x00, 0x00, 0x00,
};

static int _tda10021_writereg (struct tda10021_state* state, u8 reg, u8 data)
{
        u8 buf[] = { reg, data };
        struct i2c_msg msg = { .addr = state->config->demod_address, .flags = 0, .buf = buf, .len = 2 };
        int ret;

        ret = i2c_transfer (state->i2c, &msg, 1);
        if (ret != 1)
                printk("DVB: TDA10021(%d): %s, writereg error "
                        "(reg == 0x%02x, val == 0x%02x, ret == %i)\n",
                        state->frontend.dvb->num, __func__, reg, data, ret);

        msleep(10);
        return (ret != 1) ? -EREMOTEIO : 0;
}

static u8 tda10021_readreg (struct tda10021_state* state, u8 reg)
{
        u8 b0 [] = { reg };
        u8 b1 [] = { 0 };
        struct i2c_msg msg [] = { { .addr = state->config->demod_address, .flags = 0, .buf = b0, .len = 1 },
                                  { .addr = state->config->demod_address, .flags = I2C_M_RD, .buf = b1, .len = 1 } };
        int ret;

        ret = i2c_transfer (state->i2c, msg, 2);
        // Don't print an error message if the id is read.
        if (ret != 2 && reg != 0x1a)
                printk("DVB: TDA10021: %s: readreg error (ret == %i)\n",
                                __func__, ret);
        return b1[0];
}

//get access to tuner
static int lock_tuner(struct tda10021_state* state)
{
        u8 buf[2] = { 0x0f, tda10021_inittab[0x0f] | 0x80 };
        struct i2c_msg msg = {.addr=state->config->demod_address, .flags=0, .buf=buf, .len=2};

        if(i2c_transfer(state->i2c, &msg, 1) != 1)
        {
                printk("tda10021: lock tuner fails\n");
                return -EREMOTEIO;
        }
        return 0;
}

//release access from tuner
static int unlock_tuner(struct tda10021_state* state)
{
        u8 buf[2] = { 0x0f, tda10021_inittab[0x0f] & 0x7f };
        struct i2c_msg msg_post={.addr=state->config->demod_address, .flags=0, .buf=buf, .len=2};

        if(i2c_transfer(state->i2c, &msg_post, 1) != 1)
        {
                printk("tda10021: unlock tuner fails\n");
                return -EREMOTEIO;
        }
        return 0;
}

static int tda10021_setup_reg0 (struct tda10021_state* state, u8 reg0,
                                fe_spectral_inversion_t inversion)
{
        reg0 |= state->reg0 & 0x63;

        if ((INVERSION_ON == inversion) ^ (state->config->invert == 0))
                reg0 &= ~0x20;
        else
                reg0 |= 0x20;

        _tda10021_writereg (state, 0x00, reg0 & 0xfe);
        _tda10021_writereg (state, 0x00, reg0 | 0x01);

        state->reg0 = reg0;
        return 0;
}

static int tda10021_set_symbolrate (struct tda10021_state* state, u32 symbolrate)
{
        s32 BDR;
        s32 BDRI;
        s16 SFIL=0;
        u16 NDEC = 0;
        u32 tmp, ratio;

        if (symbolrate > XIN/2)
                symbolrate = XIN/2;
        if (symbolrate < 500000)
                symbolrate = 500000;

        if (symbolrate < XIN/16) NDEC = 1;
        if (symbolrate < XIN/32) NDEC = 2;
        if (symbolrate < XIN/64) NDEC = 3;

        if (symbolrate < (u32)(XIN/12.3)) SFIL = 1;
        if (symbolrate < (u32)(XIN/16))  SFIL = 0;
        if (symbolrate < (u32)(XIN/24.6)) SFIL = 1;
        if (symbolrate < (u32)(XIN/32))  SFIL = 0;
        if (symbolrate < (u32)(XIN/49.2)) SFIL = 1;
        if (symbolrate < (u32)(XIN/64))  SFIL = 0;
        if (symbolrate < (u32)(XIN/98.4)) SFIL = 1;

        symbolrate <<= NDEC;
        ratio = (symbolrate << 4) / FIN;
        tmp =  ((symbolrate << 4) % FIN) << 8;
        ratio = (ratio << 8) + tmp / FIN;
        tmp = (tmp % FIN) << 8;
        ratio = (ratio << 8) + DIV_ROUND_CLOSEST(tmp, FIN);

        BDR = ratio;
        BDRI = (((XIN << 5) / symbolrate) + 1) / 2;

        if (BDRI > 0xFF)
                BDRI = 0xFF;

        SFIL = (SFIL << 4) | tda10021_inittab[0x0E];

        NDEC = (NDEC << 6) | tda10021_inittab[0x03];

        _tda10021_writereg (state, 0x03, NDEC);
        _tda10021_writereg (state, 0x0a, BDR&0xff);
        _tda10021_writereg (state, 0x0b, (BDR>> 8)&0xff);
        _tda10021_writereg (state, 0x0c, (BDR>>16)&0x3f);

        _tda10021_writereg (state, 0x0d, BDRI);
        _tda10021_writereg (state, 0x0e, SFIL);

        return 0;
}

static int tda10021_init (struct dvb_frontend *fe)
{
        struct tda10021_state* state = fe->demodulator_priv;
        int i;

        dprintk("DVB: TDA10021(%d): init chip\n", fe->adapter->num);

        //_tda10021_writereg (fe, 0, 0);

        for (i=0; i<tda10021_inittab_size; i++)
                _tda10021_writereg (state, i, tda10021_inittab[i]);

        _tda10021_writereg (state, 0x34, state->pwm);

        //Comment by markus
        //0x2A[3-0] == PDIV -> P multiplaying factor (P=PDIV+1)(default 0)
        //0x2A[4] == BYPPLL -> Power down mode (default 1)
        //0x2A[5] == LCK -> PLL Lock Flag
        //0x2A[6] == POLAXIN -> Polarity of the input reference clock (default 0)

        //Activate PLL
        _tda10021_writereg(state, 0x2a, tda10021_inittab[0x2a] & 0xef);
        return 0;
}

struct qam_params {
        u8 conf, agcref, lthr, mseth, aref;
};

static int tda10021_set_parameters(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        u32 delsys  = c->delivery_system;
        unsigned qam = c->modulation;
        bool is_annex_c;
        u32 reg0x3d;
        struct tda10021_state* state = fe->demodulator_priv;
        static const struct qam_params qam_params[] = {
                /* Modulation  Conf  AGCref  LTHR  MSETH  AREF */
                [QPSK]     = { 0x14, 0x78,   0x78, 0x8c,  0x96 },
                [QAM_16]   = { 0x00, 0x8c,   0x87, 0xa2,  0x91 },
                [QAM_32]   = { 0x04, 0x8c,   0x64, 0x74,  0x96 },
                [QAM_64]   = { 0x08, 0x6a,   0x46, 0x43,  0x6a },
                [QAM_128]  = { 0x0c, 0x78,   0x36, 0x34,  0x7e },
                [QAM_256]  = { 0x10, 0x5c,   0x26, 0x23,  0x6b },
        };

        switch (delsys) {
        case SYS_DVBC_ANNEX_A:
                is_annex_c = false;
                break;
        case SYS_DVBC_ANNEX_C:
                is_annex_c = true;
                break;
        default:
                return -EINVAL;
        }

        /*
         * gcc optimizes the code bellow the same way as it would code:
         *           "if (qam > 5) return -EINVAL;"
         * Yet, the code is clearer, as it shows what QAM standards are
         * supported by the driver, and avoids the usage of magic numbers on
         * it.
         */
        switch (qam) {
        case QPSK:
        case QAM_16:
        case QAM_32:
        case QAM_64:
        case QAM_128:
        case QAM_256:
                break;
        default:
                return -EINVAL;
        }

        if (c->inversion != INVERSION_ON && c->inversion != INVERSION_OFF)
                return -EINVAL;

        /*printk("tda10021: set frequency to %d qam=%d symrate=%d\n", p->frequency,qam,p->symbol_rate);*/

        if (fe->ops.tuner_ops.set_params) {
                fe->ops.tuner_ops.set_params(fe);
                if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
        }

        tda10021_set_symbolrate(state, c->symbol_rate);
        _tda10021_writereg(state, 0x34, state->pwm);

        _tda10021_writereg(state, 0x01, qam_params[qam].agcref);
        _tda10021_writereg(state, 0x05, qam_params[qam].lthr);
        _tda10021_writereg(state, 0x08, qam_params[qam].mseth);
        _tda10021_writereg(state, 0x09, qam_params[qam].aref);

        /*
         * Bit 0 == 0 means roll-off = 0.15 (Annex A)
         *       == 1 means roll-off = 0.13 (Annex C)
         */
        reg0x3d = tda10021_readreg (state, 0x3d);
        if (is_annex_c)
                _tda10021_writereg (state, 0x3d, 0x01 | reg0x3d);
        else
                _tda10021_writereg (state, 0x3d, 0xfe & reg0x3d);
        tda10021_setup_reg0(state, qam_params[qam].conf, c->inversion);

        return 0;
}

static int tda10021_read_status(struct dvb_frontend* fe, fe_status_t* status)
{
        struct tda10021_state* state = fe->demodulator_priv;
        int sync;

        *status = 0;
        //0x11[0] == EQALGO -> Equalizer algorithms state
        //0x11[1] == CARLOCK -> Carrier locked
        //0x11[2] == FSYNC -> Frame synchronisation
        //0x11[3] == FEL -> Front End locked
        //0x11[6] == NODVB -> DVB Mode Information
        sync = tda10021_readreg (state, 0x11);

        if (sync & 2)
                *status |= FE_HAS_SIGNAL|FE_HAS_CARRIER;

        if (sync & 4)
                *status |= FE_HAS_SYNC|FE_HAS_VITERBI;

        if (sync & 8)
                *status |= FE_HAS_LOCK;

        return 0;
}

static int tda10021_read_ber(struct dvb_frontend* fe, u32* ber)
{
        struct tda10021_state* state = fe->demodulator_priv;

        u32 _ber = tda10021_readreg(state, 0x14) |
                (tda10021_readreg(state, 0x15) << 8) |
                ((tda10021_readreg(state, 0x16) & 0x0f) << 16);
        _tda10021_writereg(state, 0x10, (tda10021_readreg(state, 0x10) & ~0xc0)
                                        | (tda10021_inittab[0x10] & 0xc0));
        *ber = 10 * _ber;

        return 0;
}

static int tda10021_read_signal_strength(struct dvb_frontend* fe, u16* strength)
{
        struct tda10021_state* state = fe->demodulator_priv;

        u8 config = tda10021_readreg(state, 0x02);
        u8 gain = tda10021_readreg(state, 0x17);
        if (config & 0x02)
                /* the agc value is inverted */
                gain = ~gain;
        *strength = (gain << 8) | gain;

        return 0;
}

static int tda10021_read_snr(struct dvb_frontend* fe, u16* snr)
{
        struct tda10021_state* state = fe->demodulator_priv;

        u8 quality = ~tda10021_readreg(state, 0x18);
        *snr = (quality << 8) | quality;

        return 0;
}

static int tda10021_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
{
        struct tda10021_state* state = fe->demodulator_priv;

        *ucblocks = tda10021_readreg (state, 0x13) & 0x7f;
        if (*ucblocks == 0x7f)
                *ucblocks = 0xffffffff;

        /* reset uncorrected block counter */
        _tda10021_writereg (state, 0x10, tda10021_inittab[0x10] & 0xdf);
        _tda10021_writereg (state, 0x10, tda10021_inittab[0x10]);

        return 0;
}

static int tda10021_get_frontend(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        struct tda10021_state* state = fe->demodulator_priv;
        int sync;
        s8 afc = 0;

        sync = tda10021_readreg(state, 0x11);
        afc = tda10021_readreg(state, 0x19);
        if (verbose) {
                /* AFC only valid when carrier has been recovered */
                printk(sync & 2 ? "DVB: TDA10021(%d): AFC (%d) %dHz\n" :
                                  "DVB: TDA10021(%d): [AFC (%d) %dHz]\n",
                        state->frontend.dvb->num, afc,
                       -((s32)p->symbol_rate * afc) >> 10);
        }

        p->inversion = ((state->reg0 & 0x20) == 0x20) ^ (state->config->invert != 0) ? INVERSION_ON : INVERSION_OFF;
        p->modulation = ((state->reg0 >> 2) & 7) + QAM_16;

        p->fec_inner = FEC_NONE;
        p->frequency = ((p->frequency + 31250) / 62500) * 62500;

        if (sync & 2)
                p->frequency -= ((s32)p->symbol_rate * afc) >> 10;

        return 0;
}

static int tda10021_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
{
        struct tda10021_state* state = fe->demodulator_priv;

        if (enable) {
                lock_tuner(state);
        } else {
                unlock_tuner(state);
        }
        return 0;
}

static int tda10021_sleep(struct dvb_frontend* fe)
{
        struct tda10021_state* state = fe->demodulator_priv;

        _tda10021_writereg (state, 0x1b, 0x02);  /* pdown ADC */
        _tda10021_writereg (state, 0x00, 0x80);  /* standby */

        return 0;
}

static void tda10021_release(struct dvb_frontend* fe)
{
        struct tda10021_state* state = fe->demodulator_priv;
        kfree(state);
}

static struct dvb_frontend_ops tda10021_ops;

struct dvb_frontend* tda10021_attach(const struct tda1002x_config* config,
                                     struct i2c_adapter* i2c,
                                     u8 pwm)
{
        struct tda10021_state* state = NULL;
        u8 id;

        /* allocate memory for the internal state */
        state = kzalloc(sizeof(struct tda10021_state), GFP_KERNEL);
        if (state == NULL) goto error;

        /* setup the state */
        state->config = config;
        state->i2c = i2c;
        state->pwm = pwm;
        state->reg0 = tda10021_inittab[0];

        /* check if the demod is there */
        id = tda10021_readreg(state, 0x1a);
        if ((id & 0xf0) != 0x70) goto error;

        /* Don't claim TDA10023 */
        if (id == 0x7d)
                goto error;

        printk("TDA10021: i2c-addr = 0x%02x, id = 0x%02x\n",
               state->config->demod_address, id);

        /* create dvb_frontend */
        memcpy(&state->frontend.ops, &tda10021_ops, sizeof(struct dvb_frontend_ops));
        state->frontend.demodulator_priv = state;
        return &state->frontend;

error:
        kfree(state);
        return NULL;
}

static struct dvb_frontend_ops tda10021_ops = {
        .delsys = { SYS_DVBC_ANNEX_A, SYS_DVBC_ANNEX_C },
        .info = {
                .name = "Philips TDA10021 DVB-C",
                .frequency_stepsize = 62500,
                .frequency_min = 47000000,
                .frequency_max = 862000000,
                .symbol_rate_min = (XIN/2)/64,     /* SACLK/64 == (XIN/2)/64 */
                .symbol_rate_max = (XIN/2)/4,      /* SACLK/4 */
        #if 0
                .frequency_tolerance = ???,
                .symbol_rate_tolerance = ???,  /* ppm */  /* == 8% (spec p. 5) */
        #endif
                .caps = 0x400 | //FE_CAN_QAM_4
                        FE_CAN_QAM_16 | FE_CAN_QAM_32 | FE_CAN_QAM_64 |
                        FE_CAN_QAM_128 | FE_CAN_QAM_256 |
                        FE_CAN_FEC_AUTO
        },

        .release = tda10021_release,

        .init = tda10021_init,
        .sleep = tda10021_sleep,
        .i2c_gate_ctrl = tda10021_i2c_gate_ctrl,

        .set_frontend = tda10021_set_parameters,
        .get_frontend = tda10021_get_frontend,

        .read_status = tda10021_read_status,
        .read_ber = tda10021_read_ber,
        .read_signal_strength = tda10021_read_signal_strength,
        .read_snr = tda10021_read_snr,
        .read_ucblocks = tda10021_read_ucblocks,
};

module_param(verbose, int, 0644);
MODULE_PARM_DESC(verbose, "print AFC offset after tuning for debugging the PWM setting");

MODULE_DESCRIPTION("Philips TDA10021 DVB-C demodulator driver");
MODULE_AUTHOR("Ralph Metzler, Holger Waechtler, Markus Schulz");
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(tda10021_attach);