/*
 *  Driver for Conexant CX24113/CX24128 Tuner (Satellite)
 *
 *  Copyright (C) 2007-8 Patrick Boettcher <pb@linuxtv.org>
 *
 *  Developed for BBTI / Technisat
 *
 *  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/kernel.h>
#include <linux/module.h>
#include <linux/init.h>

#include <media/dvb_frontend.h>
#include "cx24113.h"

static int debug;

#define cx_info(args...) do { printk(KERN_INFO "CX24113: " args); } while (0)
#define cx_err(args...)  do { printk(KERN_ERR  "CX24113: " args); } while (0)

#define dprintk(args...) \
        do { \
                if (debug) { \
                        printk(KERN_DEBUG "CX24113: %s: ", __func__); \
                        printk(args); \
                } \
        } while (0)

struct cx24113_state {
        struct i2c_adapter *i2c;
        const struct cx24113_config *config;

#define REV_CX24113 0x23
        u8 rev;
        u8 ver;

        u8 icp_mode:1;

#define ICP_LEVEL1 0
#define ICP_LEVEL2 1
#define ICP_LEVEL3 2
#define ICP_LEVEL4 3
        u8 icp_man:2;
        u8 icp_auto_low:2;
        u8 icp_auto_mlow:2;
        u8 icp_auto_mhi:2;
        u8 icp_auto_hi:2;
        u8 icp_dig;

#define LNA_MIN_GAIN 0
#define LNA_MID_GAIN 1
#define LNA_MAX_GAIN 2
        u8 lna_gain:2;

        u8 acp_on:1;

        u8 vco_mode:2;
        u8 vco_shift:1;
#define VCOBANDSEL_6 0x80
#define VCOBANDSEL_5 0x01
#define VCOBANDSEL_4 0x02
#define VCOBANDSEL_3 0x04
#define VCOBANDSEL_2 0x08
#define VCOBANDSEL_1 0x10
        u8 vco_band;

#define VCODIV4 4
#define VCODIV2 2
        u8 vcodiv;

        u8 bs_delay:4;
        u16 bs_freqcnt:13;
        u16 bs_rdiv;
        u8 prescaler_mode:1;

        u8 rfvga_bias_ctrl;

        s16 tuner_gain_thres;
        u8  gain_level;

        u32 frequency;

        u8 refdiv;

        u8 Fwindow_enabled;
};

static int cx24113_writereg(struct cx24113_state *state, int reg, int data)
{
        u8 buf[] = { reg, data };
        struct i2c_msg msg = { .addr = state->config->i2c_addr,
                .flags = 0, .buf = buf, .len = 2 };
        int err = i2c_transfer(state->i2c, &msg, 1);
        if (err != 1) {
                printk(KERN_DEBUG "%s: writereg error(err == %i, reg == 0x%02x, data == 0x%02x)\n",
                       __func__, err, reg, data);
                return err;
        }

        return 0;
}

static int cx24113_readreg(struct cx24113_state *state, u8 reg)
{
        int ret;
        u8 b;
        struct i2c_msg msg[] = {
                { .addr = state->config->i2c_addr,
                        .flags = 0, .buf = &reg, .len = 1 },
                { .addr = state->config->i2c_addr,
                        .flags = I2C_M_RD, .buf = &b, .len = 1 }
        };

        ret = i2c_transfer(state->i2c, msg, 2);

        if (ret != 2) {
                printk(KERN_DEBUG "%s: reg=0x%x (error=%d)\n",
                        __func__, reg, ret);
                return ret;
        }

        return b;
}

static void cx24113_set_parameters(struct cx24113_state *state)
{
        u8 r;

        r = cx24113_readreg(state, 0x10) & 0x82;
        r |= state->icp_mode;
        r |= state->icp_man << 4;
        r |= state->icp_dig << 2;
        r |= state->prescaler_mode << 5;
        cx24113_writereg(state, 0x10, r);

        r = (state->icp_auto_low  << 0) | (state->icp_auto_mlow << 2)
                | (state->icp_auto_mhi << 4) | (state->icp_auto_hi << 6);
        cx24113_writereg(state, 0x11, r);

        if (state->rev == REV_CX24113) {
                r = cx24113_readreg(state, 0x20) & 0xec;
                r |= state->lna_gain;
                r |= state->rfvga_bias_ctrl << 4;
                cx24113_writereg(state, 0x20, r);
        }

        r = cx24113_readreg(state, 0x12) & 0x03;
        r |= state->acp_on << 2;
        r |= state->bs_delay << 4;
        cx24113_writereg(state, 0x12, r);

        r = cx24113_readreg(state, 0x18) & 0x40;
        r |= state->vco_shift;
        if (state->vco_band == VCOBANDSEL_6)
                r |= (1 << 7);
        else
                r |= (state->vco_band << 1);
        cx24113_writereg(state, 0x18, r);

        r  = cx24113_readreg(state, 0x14) & 0x20;
        r |= (state->vco_mode << 6) | ((state->bs_freqcnt >> 8) & 0x1f);
        cx24113_writereg(state, 0x14, r);
        cx24113_writereg(state, 0x15, (state->bs_freqcnt        & 0xff));

        cx24113_writereg(state, 0x16, (state->bs_rdiv >> 4) & 0xff);
        r = (cx24113_readreg(state, 0x17) & 0x0f) |
                ((state->bs_rdiv & 0x0f) << 4);
        cx24113_writereg(state, 0x17, r);
}

#define VGA_0 0x00
#define VGA_1 0x04
#define VGA_2 0x02
#define VGA_3 0x06
#define VGA_4 0x01
#define VGA_5 0x05
#define VGA_6 0x03
#define VGA_7 0x07

#define RFVGA_0 0x00
#define RFVGA_1 0x01
#define RFVGA_2 0x02
#define RFVGA_3 0x03

static int cx24113_set_gain_settings(struct cx24113_state *state,
                s16 power_estimation)
{
        u8 ampout = cx24113_readreg(state, 0x1d) & 0xf0,
           vga    = cx24113_readreg(state, 0x1f) & 0x3f,
           rfvga  = cx24113_readreg(state, 0x20) & 0xf3;
        u8 gain_level = power_estimation >= state->tuner_gain_thres;

        dprintk("power estimation: %d, thres: %d, gain_level: %d/%d\n",
                        power_estimation, state->tuner_gain_thres,
                        state->gain_level, gain_level);

        if (gain_level == state->gain_level)
                return 0; /* nothing to be done */

        ampout |= 0xf;

        if (gain_level) {
                rfvga |= RFVGA_0 << 2;
                vga   |= (VGA_7 << 3) | VGA_7;
        } else {
                rfvga |= RFVGA_2 << 2;
                vga  |= (VGA_6 << 3) | VGA_2;
        }
        state->gain_level = gain_level;

        cx24113_writereg(state, 0x1d, ampout);
        cx24113_writereg(state, 0x1f, vga);
        cx24113_writereg(state, 0x20, rfvga);

        return 1; /* did something */
}

static int cx24113_set_Fref(struct cx24113_state *state, u8 high)
{
        u8 xtal = cx24113_readreg(state, 0x02);
        if (state->rev == 0x43 && state->vcodiv == VCODIV4)
                high = 1;

        xtal &= ~0x2;
        if (high)
                xtal |= high << 1;
        return cx24113_writereg(state, 0x02, xtal);
}

static int cx24113_enable(struct cx24113_state *state, u8 enable)
{
        u8 r21 = (cx24113_readreg(state, 0x21) & 0xc0) | enable;
        if (state->rev == REV_CX24113)
                r21 |= (1 << 1);
        return cx24113_writereg(state, 0x21, r21);
}

static int cx24113_set_bandwidth(struct cx24113_state *state, u32 bandwidth_khz)
{
        u8 r;

        if (bandwidth_khz <= 19000)
                r = 0x03 << 6;
        else if (bandwidth_khz <= 25000)
                r = 0x02 << 6;
        else
                r = 0x01 << 6;

        dprintk("bandwidth to be set: %d\n", bandwidth_khz);
        bandwidth_khz *= 10;
        bandwidth_khz -= 10000;
        bandwidth_khz /= 1000;
        bandwidth_khz += 5;
        bandwidth_khz /= 10;

        dprintk("bandwidth: %d %d\n", r >> 6, bandwidth_khz);

        r |= bandwidth_khz & 0x3f;

        return cx24113_writereg(state, 0x1e, r);
}

static int cx24113_set_clk_inversion(struct cx24113_state *state, u8 on)
{
        u8 r = (cx24113_readreg(state, 0x10) & 0x7f) | ((on & 0x1) << 7);
        return cx24113_writereg(state, 0x10, r);
}

static int cx24113_get_status(struct dvb_frontend *fe, u32 *status)
{
        struct cx24113_state *state = fe->tuner_priv;
        u8 r = (cx24113_readreg(state, 0x10) & 0x02) >> 1;
        if (r)
                *status |= TUNER_STATUS_LOCKED;
        dprintk("PLL locked: %d\n", r);
        return 0;
}

static u8 cx24113_set_ref_div(struct cx24113_state *state, u8 refdiv)
{
        if (state->rev == 0x43 && state->vcodiv == VCODIV4)
                refdiv = 2;
        return state->refdiv = refdiv;
}

static void cx24113_calc_pll_nf(struct cx24113_state *state, u16 *n, s32 *f)
{
        s32 N;
        s64 F;
        u64 dividend;
        u8 R, r;
        u8 vcodiv;
        u8 factor;
        s32 freq_hz = state->frequency * 1000;

        if (state->config->xtal_khz < 20000)
                factor = 1;
        else
                factor = 2;

        if (state->rev == REV_CX24113) {
                if (state->frequency >= 1100000)
                        vcodiv = VCODIV2;
                else
                        vcodiv = VCODIV4;
        } else {
                if (state->frequency >= 1165000)
                        vcodiv = VCODIV2;
                else
                        vcodiv = VCODIV4;
        }
        state->vcodiv = vcodiv;

        dprintk("calculating N/F for %dHz with vcodiv %d\n", freq_hz, vcodiv);
        R = 0;
        do {
                R = cx24113_set_ref_div(state, R + 1);

                /* calculate tuner PLL settings: */
                N =  (freq_hz / 100 * vcodiv) * R;
                N /= (state->config->xtal_khz) * factor * 2;
                N += 5;     /* For round up. */
                N /= 10;
                N -= 32;
        } while (N < 6 && R < 3);

        if (N < 6) {
                cx_err("strange frequency: N < 6\n");
                return;
        }
        F = freq_hz;
        F *= (u64) (R * vcodiv * 262144);
        dprintk("1 N: %d, F: %lld, R: %d\n", N, (long long)F, R);
        /* do_div needs an u64 as first argument */
        dividend = F;
        do_div(dividend, state->config->xtal_khz * 1000 * factor * 2);
        F = dividend;
        dprintk("2 N: %d, F: %lld, R: %d\n", N, (long long)F, R);
        F -= (N + 32) * 262144;

        dprintk("3 N: %d, F: %lld, R: %d\n", N, (long long)F, R);

        if (state->Fwindow_enabled) {
                if (F > (262144 / 2 - 1638))
                        F = 262144 / 2 - 1638;
                if (F < (-262144 / 2 + 1638))
                        F = -262144 / 2 + 1638;
                if ((F < 3277 && F > 0) || (F > -3277 && F < 0)) {
                        F = 0;
                        r = cx24113_readreg(state, 0x10);
                        cx24113_writereg(state, 0x10, r | (1 << 6));
                }
        }
        dprintk("4 N: %d, F: %lld, R: %d\n", N, (long long)F, R);

        *n = (u16) N;
        *f = (s32) F;
}


static void cx24113_set_nfr(struct cx24113_state *state, u16 n, s32 f, u8 r)
{
        u8 reg;
        cx24113_writereg(state, 0x19, (n >> 1) & 0xff);

        reg = ((n & 0x1) << 7) | ((f >> 11) & 0x7f);
        cx24113_writereg(state, 0x1a, reg);

        cx24113_writereg(state, 0x1b, (f >> 3) & 0xff);

        reg = cx24113_readreg(state, 0x1c) & 0x1f;
        cx24113_writereg(state, 0x1c, reg | ((f & 0x7) << 5));

        cx24113_set_Fref(state, r - 1);
}

static int cx24113_set_frequency(struct cx24113_state *state, u32 frequency)
{
        u8 r = 1; /* or 2 */
        u16 n = 6;
        s32 f = 0;

        r = cx24113_readreg(state, 0x14);
        cx24113_writereg(state, 0x14, r & 0x3f);

        r = cx24113_readreg(state, 0x10);
        cx24113_writereg(state, 0x10, r & 0xbf);

        state->frequency = frequency;

        dprintk("tuning to frequency: %d\n", frequency);

        cx24113_calc_pll_nf(state, &n, &f);
        cx24113_set_nfr(state, n, f, state->refdiv);

        r = cx24113_readreg(state, 0x18) & 0xbf;
        if (state->vcodiv != VCODIV2)
                r |= 1 << 6;
        cx24113_writereg(state, 0x18, r);

        /* The need for this sleep is not clear. But helps in some cases */
        msleep(5);

        r = cx24113_readreg(state, 0x1c) & 0xef;
        cx24113_writereg(state, 0x1c, r | (1 << 4));
        return 0;
}

static int cx24113_init(struct dvb_frontend *fe)
{
        struct cx24113_state *state = fe->tuner_priv;
        int ret;

        state->tuner_gain_thres = -50;
        state->gain_level = 255; /* to force a gain-setting initialization */
        state->icp_mode = 0;

        if (state->config->xtal_khz < 11000) {
                state->icp_auto_hi  = ICP_LEVEL4;
                state->icp_auto_mhi  = ICP_LEVEL4;
                state->icp_auto_mlow = ICP_LEVEL3;
                state->icp_auto_low = ICP_LEVEL3;
        } else {
                state->icp_auto_hi  = ICP_LEVEL4;
                state->icp_auto_mhi  = ICP_LEVEL4;
                state->icp_auto_mlow = ICP_LEVEL3;
                state->icp_auto_low = ICP_LEVEL2;
        }

        state->icp_dig = ICP_LEVEL3;
        state->icp_man = ICP_LEVEL1;
        state->acp_on  = 1;
        state->vco_mode = 0;
        state->vco_shift = 0;
        state->vco_band = VCOBANDSEL_1;
        state->bs_delay = 8;
        state->bs_freqcnt = 0x0fff;
        state->bs_rdiv = 0x0fff;
        state->prescaler_mode = 0;
        state->lna_gain = LNA_MAX_GAIN;
        state->rfvga_bias_ctrl = 1;
        state->Fwindow_enabled = 1;

        cx24113_set_Fref(state, 0);
        cx24113_enable(state, 0x3d);
        cx24113_set_parameters(state);

        cx24113_set_gain_settings(state, -30);

        cx24113_set_bandwidth(state, 18025);
        cx24113_set_clk_inversion(state, 1);

        if (state->config->xtal_khz >= 40000)
                ret = cx24113_writereg(state, 0x02,
                        (cx24113_readreg(state, 0x02) & 0xfb) | (1 << 2));
        else
                ret = cx24113_writereg(state, 0x02,
                        (cx24113_readreg(state, 0x02) & 0xfb) | (0 << 2));

        return ret;
}

static int cx24113_set_params(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        struct cx24113_state *state = fe->tuner_priv;
        /* for a ROLL-OFF factor of 0.35, 0.2: 600, 0.25: 625 */
        u32 roll_off = 675;
        u32 bw;

        bw  = ((c->symbol_rate/100) * roll_off) / 1000;
        bw += (10000000/100) + 5;
        bw /= 10;
        bw += 1000;
        cx24113_set_bandwidth(state, bw);

        cx24113_set_frequency(state, c->frequency);
        msleep(5);
        return cx24113_get_status(fe, &bw);
}

static s8 cx24113_agc_table[2][10] = {
        {-54, -41, -35, -30, -25, -21, -16, -10,  -6,  -2},
        {-39, -35, -30, -25, -19, -15, -11,  -5,   1,   9},
};

void cx24113_agc_callback(struct dvb_frontend *fe)
{
        struct cx24113_state *state = fe->tuner_priv;
        s16 s, i;
        if (!fe->ops.read_signal_strength)
                return;

        do {
                /* this only works with the current CX24123 implementation */
                fe->ops.read_signal_strength(fe, (u16 *) &s);
                s >>= 8;
                dprintk("signal strength: %d\n", s);
                for (i = 0; i < sizeof(cx24113_agc_table[0]); i++)
                        if (cx24113_agc_table[state->gain_level][i] > s)
                                break;
                s = -25 - i*5;
        } while (cx24113_set_gain_settings(state, s));
}
EXPORT_SYMBOL(cx24113_agc_callback);

static int cx24113_get_frequency(struct dvb_frontend *fe, u32 *frequency)
{
        struct cx24113_state *state = fe->tuner_priv;
        *frequency = state->frequency;
        return 0;
}

static void cx24113_release(struct dvb_frontend *fe)
{
        struct cx24113_state *state = fe->tuner_priv;
        dprintk("\n");
        fe->tuner_priv = NULL;
        kfree(state);
}

static const struct dvb_tuner_ops cx24113_tuner_ops = {
        .info = {
                .name           = "Conexant CX24113",
                .frequency_min  = 950000,
                .frequency_max  = 2150000,
                .frequency_step = 125,
        },

        .release       = cx24113_release,

        .init          = cx24113_init,

        .set_params    = cx24113_set_params,
        .get_frequency = cx24113_get_frequency,
        .get_status    = cx24113_get_status,
};

struct dvb_frontend *cx24113_attach(struct dvb_frontend *fe,
                const struct cx24113_config *config, struct i2c_adapter *i2c)
{
        /* allocate memory for the internal state */
        struct cx24113_state *state = kzalloc(sizeof(*state), GFP_KERNEL);
        int rc;

        if (!state)
                return NULL;

        /* setup the state */
        state->config = config;
        state->i2c = i2c;

        cx_info("trying to detect myself\n");

        /* making a dummy read, because of some expected troubles
         * after power on */
        cx24113_readreg(state, 0x00);

        rc = cx24113_readreg(state, 0x00);
        if (rc < 0) {
                cx_info("CX24113 not found.\n");
                goto error;
        }
        state->rev = rc;

        switch (rc) {
        case 0x43:
                cx_info("detected CX24113 variant\n");
                break;
        case REV_CX24113:
                cx_info("successfully detected\n");
                break;
        default:
                cx_err("unsupported device id: %x\n", state->rev);
                goto error;
        }
        state->ver = cx24113_readreg(state, 0x01);
        cx_info("version: %x\n", state->ver);

        /* create dvb_frontend */
        memcpy(&fe->ops.tuner_ops, &cx24113_tuner_ops,
                        sizeof(struct dvb_tuner_ops));
        fe->tuner_priv = state;
        return fe;

error:
        kfree(state);

        return NULL;
}
EXPORT_SYMBOL(cx24113_attach);

module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Activates frontend debugging (default:0)");

MODULE_AUTHOR("Patrick Boettcher <pb@linuxtv.org>");
MODULE_DESCRIPTION("DVB Frontend module for Conexant CX24113/CX24128hardware");
MODULE_LICENSE("GPL");