/*
 * Driver for
 *    Samsung S5H1420 and
 *    PnpNetwork PN1010 QPSK Demodulator
 *
 * Copyright (C) 2005 Andrew de Quincey <adq_dvb@lidskialf.net>
 * Copyright (C) 2005-8 Patrick Boettcher <pb@linuxtv.org>
 *
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <asm/div64.h>

#include <linux/i2c.h>


#include "dvb_frontend.h"
#include "s5h1420.h"
#include "s5h1420_priv.h"

#define TONE_FREQ 22000

struct s5h1420_state {
        struct i2c_adapter* i2c;
        const struct s5h1420_config* config;

        struct dvb_frontend frontend;
        struct i2c_adapter tuner_i2c_adapter;

        u8 CON_1_val;

        u8 postlocked:1;
        u32 fclk;
        u32 tunedfreq;
        enum fe_code_rate fec_inner;
        u32 symbol_rate;

        /* FIXME: ugly workaround for flexcop's incapable i2c-controller
         * it does not support repeated-start, workaround: write addr-1
         * and then read
         */
        u8 shadow[256];
};

static u32 s5h1420_getsymbolrate(struct s5h1420_state* state);
static int s5h1420_get_tune_settings(struct dvb_frontend* fe,
                                     struct dvb_frontend_tune_settings* fesettings);


static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "enable debugging");

#define dprintk(x...) do { \
        if (debug) \
                printk(KERN_DEBUG "S5H1420: " x); \
} while (0)

static u8 s5h1420_readreg(struct s5h1420_state *state, u8 reg)
{
        int ret;
        u8 b[2];
        struct i2c_msg msg[] = {
                { .addr = state->config->demod_address, .flags = 0, .buf = b, .len = 2 },
                { .addr = state->config->demod_address, .flags = 0, .buf = &reg, .len = 1 },
                { .addr = state->config->demod_address, .flags = I2C_M_RD, .buf = b, .len = 1 },
        };

        b[0] = (reg - 1) & 0xff;
        b[1] = state->shadow[(reg - 1) & 0xff];

        if (state->config->repeated_start_workaround) {
                ret = i2c_transfer(state->i2c, msg, 3);
                if (ret != 3)
                        return ret;
        } else {
                ret = i2c_transfer(state->i2c, &msg[1], 1);
                if (ret != 1)
                        return ret;
                ret = i2c_transfer(state->i2c, &msg[2], 1);
                if (ret != 1)
                        return ret;
        }

        /* dprintk("rd(%02x): %02x %02x\n", state->config->demod_address, reg, b[0]); */

        return b[0];
}

static int s5h1420_writereg (struct s5h1420_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 err;

        /* dprintk("wr(%02x): %02x %02x\n", state->config->demod_address, reg, data); */
        err = i2c_transfer(state->i2c, &msg, 1);
        if (err != 1) {
                dprintk("%s: writereg error (err == %i, reg == 0x%02x, data == 0x%02x)\n", __func__, err, reg, data);
                return -EREMOTEIO;
        }
        state->shadow[reg] = data;

        return 0;
}

static int s5h1420_set_voltage(struct dvb_frontend *fe,
                               enum fe_sec_voltage voltage)
{
        struct s5h1420_state* state = fe->demodulator_priv;

        dprintk("enter %s\n", __func__);

        switch(voltage) {
        case SEC_VOLTAGE_13:
                s5h1420_writereg(state, 0x3c,
                                 (s5h1420_readreg(state, 0x3c) & 0xfe) | 0x02);
                break;

        case SEC_VOLTAGE_18:
                s5h1420_writereg(state, 0x3c, s5h1420_readreg(state, 0x3c) | 0x03);
                break;

        case SEC_VOLTAGE_OFF:
                s5h1420_writereg(state, 0x3c, s5h1420_readreg(state, 0x3c) & 0xfd);
                break;
        }

        dprintk("leave %s\n", __func__);
        return 0;
}

static int s5h1420_set_tone(struct dvb_frontend *fe,
                            enum fe_sec_tone_mode tone)
{
        struct s5h1420_state* state = fe->demodulator_priv;

        dprintk("enter %s\n", __func__);
        switch(tone) {
        case SEC_TONE_ON:
                s5h1420_writereg(state, 0x3b,
                                 (s5h1420_readreg(state, 0x3b) & 0x74) | 0x08);
                break;

        case SEC_TONE_OFF:
                s5h1420_writereg(state, 0x3b,
                                 (s5h1420_readreg(state, 0x3b) & 0x74) | 0x01);
                break;
        }
        dprintk("leave %s\n", __func__);

        return 0;
}

static int s5h1420_send_master_cmd (struct dvb_frontend* fe,
                                    struct dvb_diseqc_master_cmd* cmd)
{
        struct s5h1420_state* state = fe->demodulator_priv;
        u8 val;
        int i;
        unsigned long timeout;
        int result = 0;

        dprintk("enter %s\n", __func__);
        if (cmd->msg_len > sizeof(cmd->msg))
                return -EINVAL;

        /* setup for DISEQC */
        val = s5h1420_readreg(state, 0x3b);
        s5h1420_writereg(state, 0x3b, 0x02);
        msleep(15);

        /* write the DISEQC command bytes */
        for(i=0; i< cmd->msg_len; i++) {
                s5h1420_writereg(state, 0x3d + i, cmd->msg[i]);
        }

        /* kick off transmission */
        s5h1420_writereg(state, 0x3b, s5h1420_readreg(state, 0x3b) |
                                      ((cmd->msg_len-1) << 4) | 0x08);

        /* wait for transmission to complete */
        timeout = jiffies + ((100*HZ) / 1000);
        while(time_before(jiffies, timeout)) {
                if (!(s5h1420_readreg(state, 0x3b) & 0x08))
                        break;

                msleep(5);
        }
        if (time_after(jiffies, timeout))
                result = -ETIMEDOUT;

        /* restore original settings */
        s5h1420_writereg(state, 0x3b, val);
        msleep(15);
        dprintk("leave %s\n", __func__);
        return result;
}

static int s5h1420_recv_slave_reply (struct dvb_frontend* fe,
                                     struct dvb_diseqc_slave_reply* reply)
{
        struct s5h1420_state* state = fe->demodulator_priv;
        u8 val;
        int i;
        int length;
        unsigned long timeout;
        int result = 0;

        /* setup for DISEQC receive */
        val = s5h1420_readreg(state, 0x3b);
        s5h1420_writereg(state, 0x3b, 0x82); /* FIXME: guess - do we need to set DIS_RDY(0x08) in receive mode? */
        msleep(15);

        /* wait for reception to complete */
        timeout = jiffies + ((reply->timeout*HZ) / 1000);
        while(time_before(jiffies, timeout)) {
                if (!(s5h1420_readreg(state, 0x3b) & 0x80)) /* FIXME: do we test DIS_RDY(0x08) or RCV_EN(0x80)? */
                        break;

                msleep(5);
        }
        if (time_after(jiffies, timeout)) {
                result = -ETIMEDOUT;
                goto exit;
        }

        /* check error flag - FIXME: not sure what this does - docs do not describe
         * beyond "error flag for diseqc receive data :( */
        if (s5h1420_readreg(state, 0x49)) {
                result = -EIO;
                goto exit;
        }

        /* check length */
        length = (s5h1420_readreg(state, 0x3b) & 0x70) >> 4;
        if (length > sizeof(reply->msg)) {
                result = -EOVERFLOW;
                goto exit;
        }
        reply->msg_len = length;

        /* extract data */
        for(i=0; i< length; i++) {
                reply->msg[i] = s5h1420_readreg(state, 0x3d + i);
        }

exit:
        /* restore original settings */
        s5h1420_writereg(state, 0x3b, val);
        msleep(15);
        return result;
}

static int s5h1420_send_burst(struct dvb_frontend *fe,
                              enum fe_sec_mini_cmd minicmd)
{
        struct s5h1420_state* state = fe->demodulator_priv;
        u8 val;
        int result = 0;
        unsigned long timeout;

        /* setup for tone burst */
        val = s5h1420_readreg(state, 0x3b);
        s5h1420_writereg(state, 0x3b, (s5h1420_readreg(state, 0x3b) & 0x70) | 0x01);

        /* set value for B position if requested */
        if (minicmd == SEC_MINI_B) {
                s5h1420_writereg(state, 0x3b, s5h1420_readreg(state, 0x3b) | 0x04);
        }
        msleep(15);

        /* start transmission */
        s5h1420_writereg(state, 0x3b, s5h1420_readreg(state, 0x3b) | 0x08);

        /* wait for transmission to complete */
        timeout = jiffies + ((100*HZ) / 1000);
        while(time_before(jiffies, timeout)) {
                if (!(s5h1420_readreg(state, 0x3b) & 0x08))
                        break;

                msleep(5);
        }
        if (time_after(jiffies, timeout))
                result = -ETIMEDOUT;

        /* restore original settings */
        s5h1420_writereg(state, 0x3b, val);
        msleep(15);
        return result;
}

static enum fe_status s5h1420_get_status_bits(struct s5h1420_state *state)
{
        u8 val;
        enum fe_status status = 0;

        val = s5h1420_readreg(state, 0x14);
        if (val & 0x02)
                status |=  FE_HAS_SIGNAL;
        if (val & 0x01)
                status |=  FE_HAS_CARRIER;
        val = s5h1420_readreg(state, 0x36);
        if (val & 0x01)
                status |=  FE_HAS_VITERBI;
        if (val & 0x20)
                status |=  FE_HAS_SYNC;
        if (status == (FE_HAS_SIGNAL|FE_HAS_CARRIER|FE_HAS_VITERBI|FE_HAS_SYNC))
                status |=  FE_HAS_LOCK;

        return status;
}

static int s5h1420_read_status(struct dvb_frontend *fe,
                               enum fe_status *status)
{
        struct s5h1420_state* state = fe->demodulator_priv;
        u8 val;

        dprintk("enter %s\n", __func__);

        if (status == NULL)
                return -EINVAL;

        /* determine lock state */
        *status = s5h1420_get_status_bits(state);

        /* fix for FEC 5/6 inversion issue - if it doesn't quite lock, invert
        the inversion, wait a bit and check again */
        if (*status == (FE_HAS_SIGNAL | FE_HAS_CARRIER | FE_HAS_VITERBI)) {
                val = s5h1420_readreg(state, Vit10);
                if ((val & 0x07) == 0x03) {
                        if (val & 0x08)
                                s5h1420_writereg(state, Vit09, 0x13);
                        else
                                s5h1420_writereg(state, Vit09, 0x1b);

                        /* wait a bit then update lock status */
                        mdelay(200);
                        *status = s5h1420_get_status_bits(state);
                }
        }

        /* perform post lock setup */
        if ((*status & FE_HAS_LOCK) && !state->postlocked) {

                /* calculate the data rate */
                u32 tmp = s5h1420_getsymbolrate(state);
                switch (s5h1420_readreg(state, Vit10) & 0x07) {
                case 0: tmp = (tmp * 2 * 1) / 2; break;
                case 1: tmp = (tmp * 2 * 2) / 3; break;
                case 2: tmp = (tmp * 2 * 3) / 4; break;
                case 3: tmp = (tmp * 2 * 5) / 6; break;
                case 4: tmp = (tmp * 2 * 6) / 7; break;
                case 5: tmp = (tmp * 2 * 7) / 8; break;
                }

                if (tmp == 0) {
                        printk(KERN_ERR "s5h1420: avoided division by 0\n");
                        tmp = 1;
                }
                tmp = state->fclk / tmp;


                /* set the MPEG_CLK_INTL for the calculated data rate */
                if (tmp < 2)
                        val = 0x00;
                else if (tmp < 5)
                        val = 0x01;
                else if (tmp < 9)
                        val = 0x02;
                else if (tmp < 13)
                        val = 0x03;
                else if (tmp < 17)
                        val = 0x04;
                else if (tmp < 25)
                        val = 0x05;
                else if (tmp < 33)
                        val = 0x06;
                else
                        val = 0x07;
                dprintk("for MPEG_CLK_INTL %d %x\n", tmp, val);

                s5h1420_writereg(state, FEC01, 0x18);
                s5h1420_writereg(state, FEC01, 0x10);
                s5h1420_writereg(state, FEC01, val);

                /* Enable "MPEG_Out" */
                val = s5h1420_readreg(state, Mpeg02);
                s5h1420_writereg(state, Mpeg02, val | (1 << 6));

                /* kicker disable */
                val = s5h1420_readreg(state, QPSK01) & 0x7f;
                s5h1420_writereg(state, QPSK01, val);

                /* DC freeze TODO it was never activated by default or it can stay activated */

                if (s5h1420_getsymbolrate(state) >= 20000000) {
                        s5h1420_writereg(state, Loop04, 0x8a);
                        s5h1420_writereg(state, Loop05, 0x6a);
                } else {
                        s5h1420_writereg(state, Loop04, 0x58);
                        s5h1420_writereg(state, Loop05, 0x27);
                }

                /* post-lock processing has been done! */
                state->postlocked = 1;
        }

        dprintk("leave %s\n", __func__);

        return 0;
}

static int s5h1420_read_ber(struct dvb_frontend* fe, u32* ber)
{
        struct s5h1420_state* state = fe->demodulator_priv;

        s5h1420_writereg(state, 0x46, 0x1d);
        mdelay(25);

        *ber = (s5h1420_readreg(state, 0x48) << 8) | s5h1420_readreg(state, 0x47);

        return 0;
}

static int s5h1420_read_signal_strength(struct dvb_frontend* fe, u16* strength)
{
        struct s5h1420_state* state = fe->demodulator_priv;

        u8 val = s5h1420_readreg(state, 0x15);

        *strength =  (u16) ((val << 8) | val);

        return 0;
}

static int s5h1420_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
{
        struct s5h1420_state* state = fe->demodulator_priv;

        s5h1420_writereg(state, 0x46, 0x1f);
        mdelay(25);

        *ucblocks = (s5h1420_readreg(state, 0x48) << 8) | s5h1420_readreg(state, 0x47);

        return 0;
}

static void s5h1420_reset(struct s5h1420_state* state)
{
        dprintk("%s\n", __func__);
        s5h1420_writereg (state, 0x01, 0x08);
        s5h1420_writereg (state, 0x01, 0x00);
        udelay(10);
}

static void s5h1420_setsymbolrate(struct s5h1420_state* state,
                                  struct dtv_frontend_properties *p)
{
        u8 v;
        u64 val;

        dprintk("enter %s\n", __func__);

        val = ((u64) p->symbol_rate / 1000ULL) * (1ULL<<24);
        if (p->symbol_rate < 29000000)
                val *= 2;
        do_div(val, (state->fclk / 1000));

        dprintk("symbol rate register: %06llx\n", (unsigned long long)val);

        v = s5h1420_readreg(state, Loop01);
        s5h1420_writereg(state, Loop01, v & 0x7f);
        s5h1420_writereg(state, Tnco01, val >> 16);
        s5h1420_writereg(state, Tnco02, val >> 8);
        s5h1420_writereg(state, Tnco03, val & 0xff);
        s5h1420_writereg(state, Loop01,  v | 0x80);
        dprintk("leave %s\n", __func__);
}

static u32 s5h1420_getsymbolrate(struct s5h1420_state* state)
{
        return state->symbol_rate;
}

static void s5h1420_setfreqoffset(struct s5h1420_state* state, int freqoffset)
{
        int val;
        u8 v;

        dprintk("enter %s\n", __func__);

        /* remember freqoffset is in kHz, but the chip wants the offset in Hz, so
         * divide fclk by 1000000 to get the correct value. */
        val = -(int) ((freqoffset * (1<<24)) / (state->fclk / 1000000));

        dprintk("phase rotator/freqoffset: %d %06x\n", freqoffset, val);

        v = s5h1420_readreg(state, Loop01);
        s5h1420_writereg(state, Loop01, v & 0xbf);
        s5h1420_writereg(state, Pnco01, val >> 16);
        s5h1420_writereg(state, Pnco02, val >> 8);
        s5h1420_writereg(state, Pnco03, val & 0xff);
        s5h1420_writereg(state, Loop01, v | 0x40);
        dprintk("leave %s\n", __func__);
}

static int s5h1420_getfreqoffset(struct s5h1420_state* state)
{
        int val;

        s5h1420_writereg(state, 0x06, s5h1420_readreg(state, 0x06) | 0x08);
        val  = s5h1420_readreg(state, 0x0e) << 16;
        val |= s5h1420_readreg(state, 0x0f) << 8;
        val |= s5h1420_readreg(state, 0x10);
        s5h1420_writereg(state, 0x06, s5h1420_readreg(state, 0x06) & 0xf7);

        if (val & 0x800000)
                val |= 0xff000000;

        /* remember freqoffset is in kHz, but the chip wants the offset in Hz, so
         * divide fclk by 1000000 to get the correct value. */
        val = (((-val) * (state->fclk/1000000)) / (1<<24));

        return val;
}

static void s5h1420_setfec_inversion(struct s5h1420_state* state,
                                     struct dtv_frontend_properties *p)
{
        u8 inversion = 0;
        u8 vit08, vit09;

        dprintk("enter %s\n", __func__);

        if (p->inversion == INVERSION_OFF)
                inversion = state->config->invert ? 0x08 : 0;
        else if (p->inversion == INVERSION_ON)
                inversion = state->config->invert ? 0 : 0x08;

        if ((p->fec_inner == FEC_AUTO) || (p->inversion == INVERSION_AUTO)) {
                vit08 = 0x3f;
                vit09 = 0;
        } else {
                switch (p->fec_inner) {
                case FEC_1_2:
                        vit08 = 0x01;
                        vit09 = 0x10;
                        break;

                case FEC_2_3:
                        vit08 = 0x02;
                        vit09 = 0x11;
                        break;

                case FEC_3_4:
                        vit08 = 0x04;
                        vit09 = 0x12;
                        break;

                case FEC_5_6:
                        vit08 = 0x08;
                        vit09 = 0x13;
                        break;

                case FEC_6_7:
                        vit08 = 0x10;
                        vit09 = 0x14;
                        break;

                case FEC_7_8:
                        vit08 = 0x20;
                        vit09 = 0x15;
                        break;

                default:
                        return;
                }
        }
        vit09 |= inversion;
        dprintk("fec: %02x %02x\n", vit08, vit09);
        s5h1420_writereg(state, Vit08, vit08);
        s5h1420_writereg(state, Vit09, vit09);
        dprintk("leave %s\n", __func__);
}

static enum fe_code_rate s5h1420_getfec(struct s5h1420_state *state)
{
        switch(s5h1420_readreg(state, 0x32) & 0x07) {
        case 0:
                return FEC_1_2;

        case 1:
                return FEC_2_3;

        case 2:
                return FEC_3_4;

        case 3:
                return FEC_5_6;

        case 4:
                return FEC_6_7;

        case 5:
                return FEC_7_8;
        }

        return FEC_NONE;
}

static enum fe_spectral_inversion
s5h1420_getinversion(struct s5h1420_state *state)
{
        if (s5h1420_readreg(state, 0x32) & 0x08)
                return INVERSION_ON;

        return INVERSION_OFF;
}

static int s5h1420_set_frontend(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        struct s5h1420_state* state = fe->demodulator_priv;
        int frequency_delta;
        struct dvb_frontend_tune_settings fesettings;

        dprintk("enter %s\n", __func__);

        /* check if we should do a fast-tune */
        s5h1420_get_tune_settings(fe, &fesettings);
        frequency_delta = p->frequency - state->tunedfreq;
        if ((frequency_delta > -fesettings.max_drift) &&
                        (frequency_delta < fesettings.max_drift) &&
                        (frequency_delta != 0) &&
                        (state->fec_inner == p->fec_inner) &&
                        (state->symbol_rate == 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);
                }
                if (fe->ops.tuner_ops.get_frequency) {
                        u32 tmp;
                        fe->ops.tuner_ops.get_frequency(fe, &tmp);
                        if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
                        s5h1420_setfreqoffset(state, p->frequency - tmp);
                } else {
                        s5h1420_setfreqoffset(state, 0);
                }
                dprintk("simple tune\n");
                return 0;
        }
        dprintk("tuning demod\n");

        /* first of all, software reset */
        s5h1420_reset(state);

        /* set s5h1420 fclk PLL according to desired symbol rate */
        if (p->symbol_rate > 33000000)
                state->fclk = 80000000;
        else if (p->symbol_rate > 28500000)
                state->fclk = 59000000;
        else if (p->symbol_rate > 25000000)
                state->fclk = 86000000;
        else if (p->symbol_rate > 1900000)
                state->fclk = 88000000;
        else
                state->fclk = 44000000;

        dprintk("pll01: %d, ToneFreq: %d\n", state->fclk/1000000 - 8, (state->fclk + (TONE_FREQ * 32) - 1) / (TONE_FREQ * 32));
        s5h1420_writereg(state, PLL01, state->fclk/1000000 - 8);
        s5h1420_writereg(state, PLL02, 0x40);
        s5h1420_writereg(state, DiS01, (state->fclk + (TONE_FREQ * 32) - 1) / (TONE_FREQ * 32));

        /* TODO DC offset removal, config parameter ? */
        if (p->symbol_rate > 29000000)
                s5h1420_writereg(state, QPSK01, 0xae | 0x10);
        else
                s5h1420_writereg(state, QPSK01, 0xac | 0x10);

        /* set misc registers */
        s5h1420_writereg(state, CON_1, 0x00);
        s5h1420_writereg(state, QPSK02, 0x00);
        s5h1420_writereg(state, Pre01, 0xb0);

        s5h1420_writereg(state, Loop01, 0xF0);
        s5h1420_writereg(state, Loop02, 0x2a); /* e7 for s5h1420 */
        s5h1420_writereg(state, Loop03, 0x79); /* 78 for s5h1420 */
        if (p->symbol_rate > 20000000)
                s5h1420_writereg(state, Loop04, 0x79);
        else
                s5h1420_writereg(state, Loop04, 0x58);
        s5h1420_writereg(state, Loop05, 0x6b);

        if (p->symbol_rate >= 8000000)
                s5h1420_writereg(state, Post01, (0 << 6) | 0x10);
        else if (p->symbol_rate >= 4000000)
                s5h1420_writereg(state, Post01, (1 << 6) | 0x10);
        else
                s5h1420_writereg(state, Post01, (3 << 6) | 0x10);

        s5h1420_writereg(state, Monitor12, 0x00); /* unfreeze DC compensation */

        s5h1420_writereg(state, Sync01, 0x33);
        s5h1420_writereg(state, Mpeg01, state->config->cdclk_polarity);
        s5h1420_writereg(state, Mpeg02, 0x3d); /* Parallel output more, disabled -> enabled later */
        s5h1420_writereg(state, Err01, 0x03); /* 0x1d for s5h1420 */

        s5h1420_writereg(state, Vit06, 0x6e); /* 0x8e for s5h1420 */
        s5h1420_writereg(state, DiS03, 0x00);
        s5h1420_writereg(state, Rf01, 0x61); /* Tuner i2c address - for the gate controller */

        /* set tuner PLL */
        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);
                s5h1420_setfreqoffset(state, 0);
        }

        /* set the reset of the parameters */
        s5h1420_setsymbolrate(state, p);
        s5h1420_setfec_inversion(state, p);

        /* start QPSK */
        s5h1420_writereg(state, QPSK01, s5h1420_readreg(state, QPSK01) | 1);

        state->fec_inner = p->fec_inner;
        state->symbol_rate = p->symbol_rate;
        state->postlocked = 0;
        state->tunedfreq = p->frequency;

        dprintk("leave %s\n", __func__);
        return 0;
}

static int s5h1420_get_frontend(struct dvb_frontend* fe,
                                struct dtv_frontend_properties *p)
{
        struct s5h1420_state* state = fe->demodulator_priv;

        p->frequency = state->tunedfreq + s5h1420_getfreqoffset(state);
        p->inversion = s5h1420_getinversion(state);
        p->symbol_rate = s5h1420_getsymbolrate(state);
        p->fec_inner = s5h1420_getfec(state);

        return 0;
}

static int s5h1420_get_tune_settings(struct dvb_frontend* fe,
                                     struct dvb_frontend_tune_settings* fesettings)
{
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        if (p->symbol_rate > 20000000) {
                fesettings->min_delay_ms = 50;
                fesettings->step_size = 2000;
                fesettings->max_drift = 8000;
        } else if (p->symbol_rate > 12000000) {
                fesettings->min_delay_ms = 100;
                fesettings->step_size = 1500;
                fesettings->max_drift = 9000;
        } else if (p->symbol_rate > 8000000) {
                fesettings->min_delay_ms = 100;
                fesettings->step_size = 1000;
                fesettings->max_drift = 8000;
        } else if (p->symbol_rate > 4000000) {
                fesettings->min_delay_ms = 100;
                fesettings->step_size = 500;
                fesettings->max_drift = 7000;
        } else if (p->symbol_rate > 2000000) {
                fesettings->min_delay_ms = 200;
                fesettings->step_size = (p->symbol_rate / 8000);
                fesettings->max_drift = 14 * fesettings->step_size;
        } else {
                fesettings->min_delay_ms = 200;
                fesettings->step_size = (p->symbol_rate / 8000);
                fesettings->max_drift = 18 * fesettings->step_size;
        }

        return 0;
}

static int s5h1420_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
{
        struct s5h1420_state* state = fe->demodulator_priv;

        if (enable)
                return s5h1420_writereg(state, 0x02, state->CON_1_val | 1);
        else
                return s5h1420_writereg(state, 0x02, state->CON_1_val & 0xfe);
}

static int s5h1420_init (struct dvb_frontend* fe)
{
        struct s5h1420_state* state = fe->demodulator_priv;

        /* disable power down and do reset */
        state->CON_1_val = state->config->serial_mpeg << 4;
        s5h1420_writereg(state, 0x02, state->CON_1_val);
        msleep(10);
        s5h1420_reset(state);

        return 0;
}

static int s5h1420_sleep(struct dvb_frontend* fe)
{
        struct s5h1420_state* state = fe->demodulator_priv;
        state->CON_1_val = 0x12;
        return s5h1420_writereg(state, 0x02, state->CON_1_val);
}

static void s5h1420_release(struct dvb_frontend* fe)
{
        struct s5h1420_state* state = fe->demodulator_priv;
        i2c_del_adapter(&state->tuner_i2c_adapter);
        kfree(state);
}

static u32 s5h1420_tuner_i2c_func(struct i2c_adapter *adapter)
{
        return I2C_FUNC_I2C;
}

static int s5h1420_tuner_i2c_tuner_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msg[], int num)
{
        struct s5h1420_state *state = i2c_get_adapdata(i2c_adap);
        struct i2c_msg m[3];
        u8 tx_open[2] = { CON_1, state->CON_1_val | 1 }; /* repeater stops once there was a stop condition */

        if (1 + num > ARRAY_SIZE(m)) {
                printk(KERN_WARNING
                       "%s: i2c xfer: num=%d is too big!\n",
                       KBUILD_MODNAME, num);
                return  -EOPNOTSUPP;
        }

        memset(m, 0, sizeof(struct i2c_msg) * (1 + num));

        m[0].addr = state->config->demod_address;
        m[0].buf  = tx_open;
        m[0].len  = 2;

        memcpy(&m[1], msg, sizeof(struct i2c_msg) * num);

        return i2c_transfer(state->i2c, m, 1 + num) == 1 + num ? num : -EIO;
}

static struct i2c_algorithm s5h1420_tuner_i2c_algo = {
        .master_xfer   = s5h1420_tuner_i2c_tuner_xfer,
        .functionality = s5h1420_tuner_i2c_func,
};

struct i2c_adapter *s5h1420_get_tuner_i2c_adapter(struct dvb_frontend *fe)
{
        struct s5h1420_state *state = fe->demodulator_priv;
        return &state->tuner_i2c_adapter;
}
EXPORT_SYMBOL(s5h1420_get_tuner_i2c_adapter);

static const struct dvb_frontend_ops s5h1420_ops;

struct dvb_frontend *s5h1420_attach(const struct s5h1420_config *config,
                                    struct i2c_adapter *i2c)
{
        /* allocate memory for the internal state */
        struct s5h1420_state *state = kzalloc(sizeof(struct s5h1420_state), GFP_KERNEL);
        u8 i;

        if (state == NULL)
                goto error;

        /* setup the state */
        state->config = config;
        state->i2c = i2c;
        state->postlocked = 0;
        state->fclk = 88000000;
        state->tunedfreq = 0;
        state->fec_inner = FEC_NONE;
        state->symbol_rate = 0;

        /* check if the demod is there + identify it */
        i = s5h1420_readreg(state, ID01);
        if (i != 0x03)
                goto error;

        memset(state->shadow, 0xff, sizeof(state->shadow));

        for (i = 0; i < 0x50; i++)
                state->shadow[i] = s5h1420_readreg(state, i);

        /* create dvb_frontend */
        memcpy(&state->frontend.ops, &s5h1420_ops, sizeof(struct dvb_frontend_ops));
        state->frontend.demodulator_priv = state;

        /* create tuner i2c adapter */
        strlcpy(state->tuner_i2c_adapter.name, "S5H1420-PN1010 tuner I2C bus",
                sizeof(state->tuner_i2c_adapter.name));
        state->tuner_i2c_adapter.algo      = &s5h1420_tuner_i2c_algo;
        state->tuner_i2c_adapter.algo_data = NULL;
        i2c_set_adapdata(&state->tuner_i2c_adapter, state);
        if (i2c_add_adapter(&state->tuner_i2c_adapter) < 0) {
                printk(KERN_ERR "S5H1420/PN1010: tuner i2c bus could not be initialized\n");
                goto error;
        }

        return &state->frontend;

error:
        kfree(state);
        return NULL;
}
EXPORT_SYMBOL(s5h1420_attach);

static const struct dvb_frontend_ops s5h1420_ops = {
        .delsys = { SYS_DVBS },
        .info = {
                .name     = "Samsung S5H1420/PnpNetwork PN1010 DVB-S",
                .frequency_min    = 950000,
                .frequency_max    = 2150000,
                .frequency_stepsize = 125,     /* kHz for QPSK frontends */
                .frequency_tolerance  = 29500,
                .symbol_rate_min  = 1000000,
                .symbol_rate_max  = 45000000,
                /*  .symbol_rate_tolerance  = ???,*/
                .caps = FE_CAN_INVERSION_AUTO |
                FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
                FE_CAN_FEC_5_6 | FE_CAN_FEC_6_7 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
                FE_CAN_QPSK
        },

        .release = s5h1420_release,

        .init = s5h1420_init,
        .sleep = s5h1420_sleep,
        .i2c_gate_ctrl = s5h1420_i2c_gate_ctrl,

        .set_frontend = s5h1420_set_frontend,
        .get_frontend = s5h1420_get_frontend,
        .get_tune_settings = s5h1420_get_tune_settings,

        .read_status = s5h1420_read_status,
        .read_ber = s5h1420_read_ber,
        .read_signal_strength = s5h1420_read_signal_strength,
        .read_ucblocks = s5h1420_read_ucblocks,

        .diseqc_send_master_cmd = s5h1420_send_master_cmd,
        .diseqc_recv_slave_reply = s5h1420_recv_slave_reply,
        .diseqc_send_burst = s5h1420_send_burst,
        .set_tone = s5h1420_set_tone,
        .set_voltage = s5h1420_set_voltage,
};

MODULE_DESCRIPTION("Samsung S5H1420/PnpNetwork PN1010 DVB-S Demodulator driver");
MODULE_AUTHOR("Andrew de Quincey, Patrick Boettcher");
MODULE_LICENSE("GPL");