// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Driver for Silicon Labs Si2161 DVB-T and Si2165 DVB-C/-T Demodulator
 *
 *  Copyright (C) 2013-2017 Matthias Schwarzott <zzam@gentoo.org>
 *
 *  References:
 *  http://www.silabs.com/Support%20Documents/TechnicalDocs/Si2165-short.pdf
 */

#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 <linux/firmware.h>
#include <linux/regmap.h>

#include <media/dvb_frontend.h>
#include <media/dvb_math.h>
#include "si2165_priv.h"
#include "si2165.h"

/*
 * Hauppauge WinTV-HVR-930C-HD B130 / PCTV QuatroStick 521e 1113xx
 * uses 16 MHz xtal
 *
 * Hauppauge WinTV-HVR-930C-HD B131 / PCTV QuatroStick 522e 1114xx
 * uses 24 MHz clock provided by tuner
 */

struct si2165_state {
        struct i2c_client *client;

        struct regmap *regmap;

        struct dvb_frontend fe;

        struct si2165_config config;

        u8 chip_revcode;
        u8 chip_type;

        /* calculated by xtal and div settings */
        u32 fvco_hz;
        u32 sys_clk;
        u32 adc_clk;

        /* DVBv3 stats */
        u64 ber_prev;

        bool has_dvbc;
        bool has_dvbt;
        bool firmware_loaded;
};

static int si2165_write(struct si2165_state *state, const u16 reg,
                        const u8 *src, const int count)
{
        int ret;

        dev_dbg(&state->client->dev, "i2c write: reg: 0x%04x, data: %*ph\n",
                reg, count, src);

        ret = regmap_bulk_write(state->regmap, reg, src, count);

        if (ret)
                dev_err(&state->client->dev, "%s: ret == %d\n", __func__, ret);

        return ret;
}

static int si2165_read(struct si2165_state *state,
                       const u16 reg, u8 *val, const int count)
{
        int ret = regmap_bulk_read(state->regmap, reg, val, count);

        if (ret) {
                dev_err(&state->client->dev, "%s: error (addr %02x reg %04x error (ret == %i)\n",
                        __func__, state->config.i2c_addr, reg, ret);
                return ret;
        }

        dev_dbg(&state->client->dev, "i2c read: reg: 0x%04x, data: %*ph\n",
                reg, count, val);

        return 0;
}

static int si2165_readreg8(struct si2165_state *state,
                           const u16 reg, u8 *val)
{
        unsigned int val_tmp;
        int ret = regmap_read(state->regmap, reg, &val_tmp);
        *val = (u8)val_tmp;
        dev_dbg(&state->client->dev, "reg read: R(0x%04x)=0x%02x\n", reg, *val);
        return ret;
}

static int si2165_readreg16(struct si2165_state *state,
                            const u16 reg, u16 *val)
{
        u8 buf[2];

        int ret = si2165_read(state, reg, buf, 2);
        *val = buf[0] | buf[1] << 8;
        dev_dbg(&state->client->dev, "reg read: R(0x%04x)=0x%04x\n", reg, *val);
        return ret;
}

static int si2165_readreg24(struct si2165_state *state,
                            const u16 reg, u32 *val)
{
        u8 buf[3];

        int ret = si2165_read(state, reg, buf, 3);
        *val = buf[0] | buf[1] << 8 | buf[2] << 16;
        dev_dbg(&state->client->dev, "reg read: R(0x%04x)=0x%06x\n", reg, *val);
        return ret;
}

static int si2165_writereg8(struct si2165_state *state, const u16 reg, u8 val)
{
        return regmap_write(state->regmap, reg, val);
}

static int si2165_writereg16(struct si2165_state *state, const u16 reg, u16 val)
{
        u8 buf[2] = { val & 0xff, (val >> 8) & 0xff };

        return si2165_write(state, reg, buf, 2);
}

static int si2165_writereg24(struct si2165_state *state, const u16 reg, u32 val)
{
        u8 buf[3] = { val & 0xff, (val >> 8) & 0xff, (val >> 16) & 0xff };

        return si2165_write(state, reg, buf, 3);
}

static int si2165_writereg32(struct si2165_state *state, const u16 reg, u32 val)
{
        u8 buf[4] = {
                val & 0xff,
                (val >> 8) & 0xff,
                (val >> 16) & 0xff,
                (val >> 24) & 0xff
        };
        return si2165_write(state, reg, buf, 4);
}

static int si2165_writereg_mask8(struct si2165_state *state, const u16 reg,
                                 u8 val, u8 mask)
{
        if (mask != 0xff) {
                u8 tmp;
                int ret = si2165_readreg8(state, reg, &tmp);

                if (ret < 0)
                        return ret;

                val &= mask;
                tmp &= ~mask;
                val |= tmp;
        }
        return si2165_writereg8(state, reg, val);
}

#define REG16(reg, val) \
        { (reg), (val) & 0xff }, \
        { (reg) + 1, (val) >> 8 & 0xff }
struct si2165_reg_value_pair {
        u16 reg;
        u8 val;
};

static int si2165_write_reg_list(struct si2165_state *state,
                                 const struct si2165_reg_value_pair *regs,
                                 int count)
{
        int i;
        int ret;

        for (i = 0; i < count; i++) {
                ret = si2165_writereg8(state, regs[i].reg, regs[i].val);
                if (ret < 0)
                        return ret;
        }
        return 0;
}

static int si2165_get_tune_settings(struct dvb_frontend *fe,
                                    struct dvb_frontend_tune_settings *s)
{
        s->min_delay_ms = 1000;
        return 0;
}

static int si2165_init_pll(struct si2165_state *state)
{
        u32 ref_freq_hz = state->config.ref_freq_hz;
        u8 divr = 1; /* 1..7 */
        u8 divp = 1; /* only 1 or 4 */
        u8 divn = 56; /* 1..63 */
        u8 divm = 8;
        u8 divl = 12;
        u8 buf[4];

        /*
         * hardcoded values can be deleted if calculation is verified
         * or it yields the same values as the windows driver
         */
        switch (ref_freq_hz) {
        case 16000000u:
                divn = 56;
                break;
        case 24000000u:
                divr = 2;
                divp = 4;
                divn = 19;
                break;
        default:
                /* ref_freq / divr must be between 4 and 16 MHz */
                if (ref_freq_hz > 16000000u)
                        divr = 2;

                /*
                 * now select divn and divp such that
                 * fvco is in 1624..1824 MHz
                 */
                if (1624000000u * divr > ref_freq_hz * 2u * 63u)
                        divp = 4;

                /* is this already correct regarding rounding? */
                divn = 1624000000u * divr / (ref_freq_hz * 2u * divp);
                break;
        }

        /* adc_clk and sys_clk depend on xtal and pll settings */
        state->fvco_hz = ref_freq_hz / divr
                        * 2u * divn * divp;
        state->adc_clk = state->fvco_hz / (divm * 4u);
        state->sys_clk = state->fvco_hz / (divl * 2u);

        /* write all 4 pll registers 0x00a0..0x00a3 at once */
        buf[0] = divl;
        buf[1] = divm;
        buf[2] = (divn & 0x3f) | ((divp == 1) ? 0x40 : 0x00) | 0x80;
        buf[3] = divr;
        return si2165_write(state, REG_PLL_DIVL, buf, 4);
}

static int si2165_adjust_pll_divl(struct si2165_state *state, u8 divl)
{
        state->sys_clk = state->fvco_hz / (divl * 2u);
        return si2165_writereg8(state, REG_PLL_DIVL, divl);
}

static u32 si2165_get_fe_clk(struct si2165_state *state)
{
        /* assume Oversampling mode Ovr4 is used */
        return state->adc_clk;
}

static int si2165_wait_init_done(struct si2165_state *state)
{
        int ret;
        u8 val = 0;
        int i;

        for (i = 0; i < 3; ++i) {
                ret = si2165_readreg8(state, REG_INIT_DONE, &val);
                if (ret < 0)
                        return ret;
                if (val == 0x01)
                        return 0;
                usleep_range(1000, 50000);
        }
        dev_err(&state->client->dev, "init_done was not set\n");
        return -EINVAL;
}

static int si2165_upload_firmware_block(struct si2165_state *state,
                                        const u8 *data, u32 len, u32 *poffset,
                                        u32 block_count)
{
        int ret;
        u8 buf_ctrl[4] = { 0x00, 0x00, 0x00, 0xc0 };
        u8 wordcount;
        u32 cur_block = 0;
        u32 offset = poffset ? *poffset : 0;

        if (len < 4)
                return -EINVAL;
        if (len % 4 != 0)
                return -EINVAL;

        dev_dbg(&state->client->dev,
                "fw load: %s: called with len=0x%x offset=0x%x blockcount=0x%x\n",
                __func__, len, offset, block_count);
        while (offset + 12 <= len && cur_block < block_count) {
                dev_dbg(&state->client->dev,
                        "fw load: %s: in while len=0x%x offset=0x%x cur_block=0x%x blockcount=0x%x\n",
                        __func__, len, offset, cur_block, block_count);
                wordcount = data[offset];
                if (wordcount < 1 || data[offset + 1] ||
                    data[offset + 2] || data[offset + 3]) {
                        dev_warn(&state->client->dev,
                                 "bad fw data[0..3] = %*ph\n",
                                 4, data);
                        return -EINVAL;
                }

                if (offset + 8 + wordcount * 4 > len) {
                        dev_warn(&state->client->dev,
                                 "len is too small for block len=%d, wordcount=%d\n",
                                len, wordcount);
                        return -EINVAL;
                }

                buf_ctrl[0] = wordcount - 1;

                ret = si2165_write(state, REG_DCOM_CONTROL_BYTE, buf_ctrl, 4);
                if (ret < 0)
                        goto error;
                ret = si2165_write(state, REG_DCOM_ADDR, data + offset + 4, 4);
                if (ret < 0)
                        goto error;

                offset += 8;

                while (wordcount > 0) {
                        ret = si2165_write(state, REG_DCOM_DATA,
                                           data + offset, 4);
                        if (ret < 0)
                                goto error;
                        wordcount--;
                        offset += 4;
                }
                cur_block++;
        }

        dev_dbg(&state->client->dev,
                "fw load: %s: after while len=0x%x offset=0x%x cur_block=0x%x blockcount=0x%x\n",
                __func__, len, offset, cur_block, block_count);

        if (poffset)
                *poffset = offset;

        dev_dbg(&state->client->dev,
                "fw load: %s: returned offset=0x%x\n",
                __func__, offset);

        return 0;
error:
        return ret;
}

static int si2165_upload_firmware(struct si2165_state *state)
{
        /* int ret; */
        u8 val[3];
        u16 val16;
        int ret;

        const struct firmware *fw = NULL;
        u8 *fw_file;
        const u8 *data;
        u32 len;
        u32 offset;
        u8 patch_version;
        u8 block_count;
        u16 crc_expected;

        switch (state->chip_revcode) {
        case 0x03: /* revision D */
                fw_file = SI2165_FIRMWARE_REV_D;
                break;
        default:
                dev_info(&state->client->dev, "no firmware file for revision=%d\n",
                         state->chip_revcode);
                return 0;
        }

        /* request the firmware, this will block and timeout */
        ret = request_firmware(&fw, fw_file, &state->client->dev);
        if (ret) {
                dev_warn(&state->client->dev, "firmware file '%s' not found\n",
                         fw_file);
                goto error;
        }

        data = fw->data;
        len = fw->size;

        dev_info(&state->client->dev, "downloading firmware from file '%s' size=%d\n",
                 fw_file, len);

        if (len % 4 != 0) {
                dev_warn(&state->client->dev, "firmware size is not multiple of 4\n");
                ret = -EINVAL;
                goto error;
        }

        /* check header (8 bytes) */
        if (len < 8) {
                dev_warn(&state->client->dev, "firmware header is missing\n");
                ret = -EINVAL;
                goto error;
        }

        if (data[0] != 1 || data[1] != 0) {
                dev_warn(&state->client->dev, "firmware file version is wrong\n");
                ret = -EINVAL;
                goto error;
        }

        patch_version = data[2];
        block_count = data[4];
        crc_expected = data[7] << 8 | data[6];

        /* start uploading fw */
        /* boot/wdog status */
        ret = si2165_writereg8(state, REG_WDOG_AND_BOOT, 0x00);
        if (ret < 0)
                goto error;
        /* reset */
        ret = si2165_writereg8(state, REG_RST_ALL, 0x00);
        if (ret < 0)
                goto error;
        /* boot/wdog status */
        ret = si2165_readreg8(state, REG_WDOG_AND_BOOT, val);
        if (ret < 0)
                goto error;

        /* enable reset on error */
        ret = si2165_readreg8(state, REG_EN_RST_ERROR, val);
        if (ret < 0)
                goto error;
        ret = si2165_readreg8(state, REG_EN_RST_ERROR, val);
        if (ret < 0)
                goto error;
        ret = si2165_writereg8(state, REG_EN_RST_ERROR, 0x02);
        if (ret < 0)
                goto error;

        /* start right after the header */
        offset = 8;

        dev_info(&state->client->dev, "%s: extracted patch_version=0x%02x, block_count=0x%02x, crc_expected=0x%04x\n",
                 __func__, patch_version, block_count, crc_expected);

        ret = si2165_upload_firmware_block(state, data, len, &offset, 1);
        if (ret < 0)
                goto error;

        ret = si2165_writereg8(state, REG_PATCH_VERSION, patch_version);
        if (ret < 0)
                goto error;

        /* reset crc */
        ret = si2165_writereg8(state, REG_RST_CRC, 0x01);
        if (ret)
                goto error;

        ret = si2165_upload_firmware_block(state, data, len,
                                           &offset, block_count);
        if (ret < 0) {
                dev_err(&state->client->dev,
                        "firmware could not be uploaded\n");
                goto error;
        }

        /* read crc */
        ret = si2165_readreg16(state, REG_CRC, &val16);
        if (ret)
                goto error;

        if (val16 != crc_expected) {
                dev_err(&state->client->dev,
                        "firmware crc mismatch %04x != %04x\n",
                        val16, crc_expected);
                ret = -EINVAL;
                goto error;
        }

        ret = si2165_upload_firmware_block(state, data, len, &offset, 5);
        if (ret)
                goto error;

        if (len != offset) {
                dev_err(&state->client->dev,
                        "firmware len mismatch %04x != %04x\n",
                        len, offset);
                ret = -EINVAL;
                goto error;
        }

        /* reset watchdog error register */
        ret = si2165_writereg_mask8(state, REG_WDOG_AND_BOOT, 0x02, 0x02);
        if (ret < 0)
                goto error;

        /* enable reset on error */
        ret = si2165_writereg_mask8(state, REG_EN_RST_ERROR, 0x01, 0x01);
        if (ret < 0)
                goto error;

        dev_info(&state->client->dev, "fw load finished\n");

        ret = 0;
        state->firmware_loaded = true;
error:
        if (fw) {
                release_firmware(fw);
                fw = NULL;
        }

        return ret;
}

static int si2165_init(struct dvb_frontend *fe)
{
        int ret = 0;
        struct si2165_state *state = fe->demodulator_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        u8 val;
        u8 patch_version = 0x00;

        dev_dbg(&state->client->dev, "%s: called\n", __func__);

        /* powerup */
        ret = si2165_writereg8(state, REG_CHIP_MODE, state->config.chip_mode);
        if (ret < 0)
                goto error;
        /* dsp_clock_enable */
        ret = si2165_writereg8(state, REG_DSP_CLOCK, 0x01);
        if (ret < 0)
                goto error;
        /* verify chip_mode */
        ret = si2165_readreg8(state, REG_CHIP_MODE, &val);
        if (ret < 0)
                goto error;
        if (val != state->config.chip_mode) {
                dev_err(&state->client->dev, "could not set chip_mode\n");
                return -EINVAL;
        }

        /* agc */
        ret = si2165_writereg8(state, REG_AGC_IF_TRI, 0x00);
        if (ret < 0)
                goto error;
        ret = si2165_writereg8(state, REG_AGC_IF_SLR, 0x01);
        if (ret < 0)
                goto error;
        ret = si2165_writereg8(state, REG_AGC2_OUTPUT, 0x00);
        if (ret < 0)
                goto error;
        ret = si2165_writereg8(state, REG_AGC2_CLKDIV, 0x07);
        if (ret < 0)
                goto error;
        /* rssi pad */
        ret = si2165_writereg8(state, REG_RSSI_PAD_CTRL, 0x00);
        if (ret < 0)
                goto error;
        ret = si2165_writereg8(state, REG_RSSI_ENABLE, 0x00);
        if (ret < 0)
                goto error;

        ret = si2165_init_pll(state);
        if (ret < 0)
                goto error;

        /* enable chip_init */
        ret = si2165_writereg8(state, REG_CHIP_INIT, 0x01);
        if (ret < 0)
                goto error;
        /* set start_init */
        ret = si2165_writereg8(state, REG_START_INIT, 0x01);
        if (ret < 0)
                goto error;
        ret = si2165_wait_init_done(state);
        if (ret < 0)
                goto error;

        /* disable chip_init */
        ret = si2165_writereg8(state, REG_CHIP_INIT, 0x00);
        if (ret < 0)
                goto error;

        /* ber_pkt - default 65535 */
        ret = si2165_writereg16(state, REG_BER_PKT,
                                STATISTICS_PERIOD_PKT_COUNT);
        if (ret < 0)
                goto error;

        ret = si2165_readreg8(state, REG_PATCH_VERSION, &patch_version);
        if (ret < 0)
                goto error;

        ret = si2165_writereg8(state, REG_AUTO_RESET, 0x00);
        if (ret < 0)
                goto error;

        /* dsp_addr_jump */
        ret = si2165_writereg32(state, REG_ADDR_JUMP, 0xf4000000);
        if (ret < 0)
                goto error;
        /* boot/wdog status */
        ret = si2165_readreg8(state, REG_WDOG_AND_BOOT, &val);
        if (ret < 0)
                goto error;

        if (patch_version == 0x00) {
                ret = si2165_upload_firmware(state);
                if (ret < 0)
                        goto error;
        }

        /* ts output config */
        ret = si2165_writereg8(state, REG_TS_DATA_MODE, 0x20);
        if (ret < 0)
                return ret;
        ret = si2165_writereg16(state, REG_TS_TRI, 0x00fe);
        if (ret < 0)
                return ret;
        ret = si2165_writereg24(state, REG_TS_SLR, 0x555555);
        if (ret < 0)
                return ret;
        ret = si2165_writereg8(state, REG_TS_CLK_MODE, 0x01);
        if (ret < 0)
                return ret;
        ret = si2165_writereg8(state, REG_TS_PARALLEL_MODE, 0x00);
        if (ret < 0)
                return ret;

        c = &state->fe.dtv_property_cache;
        c->cnr.len = 1;
        c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        c->post_bit_error.len = 1;
        c->post_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        c->post_bit_count.len = 1;
        c->post_bit_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;

        return 0;
error:
        return ret;
}

static int si2165_sleep(struct dvb_frontend *fe)
{
        int ret;
        struct si2165_state *state = fe->demodulator_priv;

        /* dsp clock disable */
        ret = si2165_writereg8(state, REG_DSP_CLOCK, 0x00);
        if (ret < 0)
                return ret;
        /* chip mode */
        ret = si2165_writereg8(state, REG_CHIP_MODE, SI2165_MODE_OFF);
        if (ret < 0)
                return ret;
        return 0;
}

static int si2165_read_status(struct dvb_frontend *fe, enum fe_status *status)
{
        int ret;
        u8 u8tmp;
        u32 u32tmp;
        struct si2165_state *state = fe->demodulator_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        u32 delsys = c->delivery_system;

        *status = 0;

        switch (delsys) {
        case SYS_DVBT:
                /* check fast signal type */
                ret = si2165_readreg8(state, REG_CHECK_SIGNAL, &u8tmp);
                if (ret < 0)
                        return ret;
                switch (u8tmp & 0x3) {
                case 0: /* searching */
                case 1: /* nothing */
                        break;
                case 2: /* digital signal */
                        *status |= FE_HAS_SIGNAL | FE_HAS_CARRIER;
                        break;
                }
                break;
        case SYS_DVBC_ANNEX_A:
                /* check packet sync lock */
                ret = si2165_readreg8(state, REG_PS_LOCK, &u8tmp);
                if (ret < 0)
                        return ret;
                if (u8tmp & 0x01) {
                        *status |= FE_HAS_SIGNAL;
                        *status |= FE_HAS_CARRIER;
                        *status |= FE_HAS_VITERBI;
                        *status |= FE_HAS_SYNC;
                }
                break;
        }

        /* check fec_lock */
        ret = si2165_readreg8(state, REG_FEC_LOCK, &u8tmp);
        if (ret < 0)
                return ret;
        if (u8tmp & 0x01) {
                *status |= FE_HAS_SIGNAL;
                *status |= FE_HAS_CARRIER;
                *status |= FE_HAS_VITERBI;
                *status |= FE_HAS_SYNC;
                *status |= FE_HAS_LOCK;
        }

        /* CNR */
        if (delsys == SYS_DVBC_ANNEX_A && *status & FE_HAS_VITERBI) {
                ret = si2165_readreg24(state, REG_C_N, &u32tmp);
                if (ret < 0)
                        return ret;
                /*
                 * svalue =
                 * 1000 * c_n/dB =
                 * 1000 * 10 * log10(2^24 / regval) =
                 * 1000 * 10 * (log10(2^24) - log10(regval)) =
                 * 1000 * 10 * (intlog10(2^24) - intlog10(regval)) / 2^24
                 *
                 * intlog10(x) = log10(x) * 2^24
                 * intlog10(2^24) = log10(2^24) * 2^24 = 121210686
                 */
                u32tmp = (1000 * 10 * (121210686 - (u64)intlog10(u32tmp)))
                                >> 24;
                c->cnr.stat[0].scale = FE_SCALE_DECIBEL;
                c->cnr.stat[0].svalue = u32tmp;
        } else
                c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;

        /* BER */
        if (*status & FE_HAS_VITERBI) {
                if (c->post_bit_error.stat[0].scale == FE_SCALE_NOT_AVAILABLE) {
                        /* start new sampling period to get rid of old data*/
                        ret = si2165_writereg8(state, REG_BER_RST, 0x01);
                        if (ret < 0)
                                return ret;

                        /* set scale to enter read code on next call */
                        c->post_bit_error.stat[0].scale = FE_SCALE_COUNTER;
                        c->post_bit_count.stat[0].scale = FE_SCALE_COUNTER;
                        c->post_bit_error.stat[0].uvalue = 0;
                        c->post_bit_count.stat[0].uvalue = 0;

                        /*
                         * reset DVBv3 value to deliver a good result
                         * for the first call
                         */
                        state->ber_prev = 0;

                } else {
                        ret = si2165_readreg8(state, REG_BER_AVAIL, &u8tmp);
                        if (ret < 0)
                                return ret;

                        if (u8tmp & 1) {
                                u32 biterrcnt;

                                ret = si2165_readreg24(state, REG_BER_BIT,
                                                        &biterrcnt);
                                if (ret < 0)
                                        return ret;

                                c->post_bit_error.stat[0].uvalue +=
                                        biterrcnt;
                                c->post_bit_count.stat[0].uvalue +=
                                        STATISTICS_PERIOD_BIT_COUNT;

                                /* start new sampling period */
                                ret = si2165_writereg8(state,
                                                        REG_BER_RST, 0x01);
                                if (ret < 0)
                                        return ret;

                                dev_dbg(&state->client->dev,
                                        "post_bit_error=%u post_bit_count=%u\n",
                                        biterrcnt, STATISTICS_PERIOD_BIT_COUNT);
                        }
                }
        } else {
                c->post_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
                c->post_bit_count.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
        }

        return 0;
}

static int si2165_read_snr(struct dvb_frontend *fe, u16 *snr)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;

        if (c->cnr.stat[0].scale == FE_SCALE_DECIBEL)
                *snr = div_s64(c->cnr.stat[0].svalue, 100);
        else
                *snr = 0;
        return 0;
}

static int si2165_read_ber(struct dvb_frontend *fe, u32 *ber)
{
        struct si2165_state *state = fe->demodulator_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;

        if (c->post_bit_error.stat[0].scale != FE_SCALE_COUNTER) {
                *ber = 0;
                return 0;
        }

        *ber = c->post_bit_error.stat[0].uvalue - state->ber_prev;
        state->ber_prev = c->post_bit_error.stat[0].uvalue;

        return 0;
}

static int si2165_set_oversamp(struct si2165_state *state, u32 dvb_rate)
{
        u64 oversamp;
        u32 reg_value;

        if (!dvb_rate)
                return -EINVAL;

        oversamp = si2165_get_fe_clk(state);
        oversamp <<= 23;
        do_div(oversamp, dvb_rate);
        reg_value = oversamp & 0x3fffffff;

        dev_dbg(&state->client->dev, "Write oversamp=%#x\n", reg_value);
        return si2165_writereg32(state, REG_OVERSAMP, reg_value);
}

static int si2165_set_if_freq_shift(struct si2165_state *state)
{
        struct dvb_frontend *fe = &state->fe;
        u64 if_freq_shift;
        s32 reg_value = 0;
        u32 fe_clk = si2165_get_fe_clk(state);
        u32 IF = 0;

        if (!fe->ops.tuner_ops.get_if_frequency) {
                dev_err(&state->client->dev,
                        "Error: get_if_frequency() not defined at tuner. Can't work without it!\n");
                return -EINVAL;
        }

        if (!fe_clk)
                return -EINVAL;

        fe->ops.tuner_ops.get_if_frequency(fe, &IF);
        if_freq_shift = IF;
        if_freq_shift <<= 29;

        do_div(if_freq_shift, fe_clk);
        reg_value = (s32)if_freq_shift;

        if (state->config.inversion)
                reg_value = -reg_value;

        reg_value = reg_value & 0x1fffffff;

        /* if_freq_shift, usbdump contained 0x023ee08f; */
        return si2165_writereg32(state, REG_IF_FREQ_SHIFT, reg_value);
}

static const struct si2165_reg_value_pair dvbt_regs[] = {
        /* standard = DVB-T */
        { REG_DVB_STANDARD, 0x01 },
        /* impulsive_noise_remover */
        { REG_IMPULSIVE_NOISE_REM, 0x01 },
        { REG_AUTO_RESET, 0x00 },
        /* agc2 */
        { REG_AGC2_MIN, 0x41 },
        { REG_AGC2_KACQ, 0x0e },
        { REG_AGC2_KLOC, 0x10 },
        /* agc */
        { REG_AGC_UNFREEZE_THR, 0x03 },
        { REG_AGC_CRESTF_DBX8, 0x78 },
        /* agc */
        { REG_AAF_CRESTF_DBX8, 0x78 },
        { REG_ACI_CRESTF_DBX8, 0x68 },
        /* freq_sync_range */
        REG16(REG_FREQ_SYNC_RANGE, 0x0064),
        /* gp_reg0 */
        { REG_GP_REG0_MSB, 0x00 }
};

static int si2165_set_frontend_dvbt(struct dvb_frontend *fe)
{
        int ret;
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        struct si2165_state *state = fe->demodulator_priv;
        u32 dvb_rate = 0;
        u16 bw10k;
        u32 bw_hz = p->bandwidth_hz;

        dev_dbg(&state->client->dev, "%s: called\n", __func__);

        if (!state->has_dvbt)
                return -EINVAL;

        /* no bandwidth auto-detection */
        if (bw_hz == 0)
                return -EINVAL;

        dvb_rate = bw_hz * 8 / 7;
        bw10k = bw_hz / 10000;

        ret = si2165_adjust_pll_divl(state, 12);
        if (ret < 0)
                return ret;

        /* bandwidth in 10KHz steps */
        ret = si2165_writereg16(state, REG_T_BANDWIDTH, bw10k);
        if (ret < 0)
                return ret;
        ret = si2165_set_oversamp(state, dvb_rate);
        if (ret < 0)
                return ret;

        ret = si2165_write_reg_list(state, dvbt_regs, ARRAY_SIZE(dvbt_regs));
        if (ret < 0)
                return ret;

        return 0;
}

static const struct si2165_reg_value_pair dvbc_regs[] = {
        /* standard = DVB-C */
        { REG_DVB_STANDARD, 0x05 },

        /* agc2 */
        { REG_AGC2_MIN, 0x50 },
        { REG_AGC2_KACQ, 0x0e },
        { REG_AGC2_KLOC, 0x10 },
        /* agc */
        { REG_AGC_UNFREEZE_THR, 0x03 },
        { REG_AGC_CRESTF_DBX8, 0x68 },
        /* agc */
        { REG_AAF_CRESTF_DBX8, 0x68 },
        { REG_ACI_CRESTF_DBX8, 0x50 },

        { REG_EQ_AUTO_CONTROL, 0x0d },

        { REG_KP_LOCK, 0x05 },
        { REG_CENTRAL_TAP, 0x09 },
        REG16(REG_UNKNOWN_350, 0x3e80),

        { REG_AUTO_RESET, 0x01 },
        REG16(REG_UNKNOWN_24C, 0x0000),
        REG16(REG_UNKNOWN_27C, 0x0000),
        { REG_SWEEP_STEP, 0x03 },
        { REG_AGC_IF_TRI, 0x00 },
};

static int si2165_set_frontend_dvbc(struct dvb_frontend *fe)
{
        struct si2165_state *state = fe->demodulator_priv;
        int ret;
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        const u32 dvb_rate = p->symbol_rate;
        u8 u8tmp;

        if (!state->has_dvbc)
                return -EINVAL;

        if (dvb_rate == 0)
                return -EINVAL;

        ret = si2165_adjust_pll_divl(state, 14);
        if (ret < 0)
                return ret;

        /* Oversampling */
        ret = si2165_set_oversamp(state, dvb_rate);
        if (ret < 0)
                return ret;

        switch (p->modulation) {
        case QPSK:
                u8tmp = 0x3;
                break;
        case QAM_16:
                u8tmp = 0x7;
                break;
        case QAM_32:
                u8tmp = 0x8;
                break;
        case QAM_64:
                u8tmp = 0x9;

                break;
        case QAM_128:
                u8tmp = 0xa;
                break;
        case QAM_256:
        default:
                u8tmp = 0xb;
                break;
        }
        ret = si2165_writereg8(state, REG_REQ_CONSTELLATION, u8tmp);
        if (ret < 0)
                return ret;

        ret = si2165_writereg32(state, REG_LOCK_TIMEOUT, 0x007a1200);
        if (ret < 0)
                return ret;

        ret = si2165_write_reg_list(state, dvbc_regs, ARRAY_SIZE(dvbc_regs));
        if (ret < 0)
                return ret;

        return 0;
}

static const struct si2165_reg_value_pair adc_rewrite[] = {
        { REG_ADC_RI1, 0x46 },
        { REG_ADC_RI3, 0x00 },
        { REG_ADC_RI5, 0x0a },
        { REG_ADC_RI6, 0xff },
        { REG_ADC_RI8, 0x70 }
};

static int si2165_set_frontend(struct dvb_frontend *fe)
{
        struct si2165_state *state = fe->demodulator_priv;
        struct dtv_frontend_properties *p = &fe->dtv_property_cache;
        u32 delsys = p->delivery_system;
        int ret;
        u8 val[3];

        /* initial setting of if freq shift */
        ret = si2165_set_if_freq_shift(state);
        if (ret < 0)
                return ret;

        switch (delsys) {
        case SYS_DVBT:
                ret = si2165_set_frontend_dvbt(fe);
                if (ret < 0)
                        return ret;
                break;
        case SYS_DVBC_ANNEX_A:
                ret = si2165_set_frontend_dvbc(fe);
                if (ret < 0)
                        return ret;
                break;
        default:
                return -EINVAL;
        }

        /* dsp_addr_jump */
        ret = si2165_writereg32(state, REG_ADDR_JUMP, 0xf4000000);
        if (ret < 0)
                return ret;

        if (fe->ops.tuner_ops.set_params)
                fe->ops.tuner_ops.set_params(fe);

        /* recalc if_freq_shift if IF might has changed */
        ret = si2165_set_if_freq_shift(state);
        if (ret < 0)
                return ret;

        /* boot/wdog status */
        ret = si2165_readreg8(state, REG_WDOG_AND_BOOT, val);
        if (ret < 0)
                return ret;
        ret = si2165_writereg8(state, REG_WDOG_AND_BOOT, 0x00);
        if (ret < 0)
                return ret;

        /* reset all */
        ret = si2165_writereg8(state, REG_RST_ALL, 0x00);
        if (ret < 0)
                return ret;
        /* gp_reg0 */
        ret = si2165_writereg32(state, REG_GP_REG0_LSB, 0x00000000);
        if (ret < 0)
                return ret;

        /* write adc values after each reset*/
        ret = si2165_write_reg_list(state, adc_rewrite,
                                    ARRAY_SIZE(adc_rewrite));
        if (ret < 0)
                return ret;

        /* start_synchro */
        ret = si2165_writereg8(state, REG_START_SYNCHRO, 0x01);
        if (ret < 0)
                return ret;
        /* boot/wdog status */
        ret = si2165_readreg8(state, REG_WDOG_AND_BOOT, val);
        if (ret < 0)
                return ret;

        return 0;
}

static const struct dvb_frontend_ops si2165_ops = {
        .info = {
                .name = "Silicon Labs ",
                 /* For DVB-C */
                .symbol_rate_min = 1000000,
                .symbol_rate_max = 7200000,
                /* For DVB-T */
                .frequency_stepsize_hz = 166667,
                .caps = FE_CAN_FEC_1_2 |
                        FE_CAN_FEC_2_3 |
                        FE_CAN_FEC_3_4 |
                        FE_CAN_FEC_5_6 |
                        FE_CAN_FEC_7_8 |
                        FE_CAN_FEC_AUTO |
                        FE_CAN_QPSK |
                        FE_CAN_QAM_16 |
                        FE_CAN_QAM_32 |
                        FE_CAN_QAM_64 |
                        FE_CAN_QAM_128 |
                        FE_CAN_QAM_256 |
                        FE_CAN_GUARD_INTERVAL_AUTO |
                        FE_CAN_HIERARCHY_AUTO |
                        FE_CAN_MUTE_TS |
                        FE_CAN_TRANSMISSION_MODE_AUTO |
                        FE_CAN_RECOVER
        },

        .get_tune_settings = si2165_get_tune_settings,

        .init = si2165_init,
        .sleep = si2165_sleep,

        .set_frontend      = si2165_set_frontend,
        .read_status       = si2165_read_status,
        .read_snr          = si2165_read_snr,
        .read_ber          = si2165_read_ber,
};

static int si2165_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
{
        struct si2165_state *state = NULL;
        struct si2165_platform_data *pdata = client->dev.platform_data;
        int n;
        int ret = 0;
        u8 val;
        char rev_char;
        const char *chip_name;
        static const struct regmap_config regmap_config = {
                .reg_bits = 16,
                .val_bits = 8,
                .max_register = 0x08ff,
        };

        /* allocate memory for the internal state */
        state = kzalloc(sizeof(*state), GFP_KERNEL);
        if (!state) {
                ret = -ENOMEM;
                goto error;
        }

        /* create regmap */
        state->regmap = devm_regmap_init_i2c(client, &regmap_config);
        if (IS_ERR(state->regmap)) {
                ret = PTR_ERR(state->regmap);
                goto error;
        }

        /* setup the state */
        state->client = client;
        state->config.i2c_addr = client->addr;
        state->config.chip_mode = pdata->chip_mode;
        state->config.ref_freq_hz = pdata->ref_freq_hz;
        state->config.inversion = pdata->inversion;

        if (state->config.ref_freq_hz < 4000000 ||
            state->config.ref_freq_hz > 27000000) {
                dev_err(&state->client->dev, "ref_freq of %d Hz not supported by this driver\n",
                        state->config.ref_freq_hz);
                ret = -EINVAL;
                goto error;
        }

        /* create dvb_frontend */
        memcpy(&state->fe.ops, &si2165_ops,
               sizeof(struct dvb_frontend_ops));
        state->fe.ops.release = NULL;
        state->fe.demodulator_priv = state;
        i2c_set_clientdata(client, state);

        /* powerup */
        ret = si2165_writereg8(state, REG_CHIP_MODE, state->config.chip_mode);
        if (ret < 0)
                goto nodev_error;

        ret = si2165_readreg8(state, REG_CHIP_MODE, &val);
        if (ret < 0)
                goto nodev_error;
        if (val != state->config.chip_mode)
                goto nodev_error;

        ret = si2165_readreg8(state, REG_CHIP_REVCODE, &state->chip_revcode);
        if (ret < 0)
                goto nodev_error;

        ret = si2165_readreg8(state, REV_CHIP_TYPE, &state->chip_type);
        if (ret < 0)
                goto nodev_error;

        /* powerdown */
        ret = si2165_writereg8(state, REG_CHIP_MODE, SI2165_MODE_OFF);
        if (ret < 0)
                goto nodev_error;

        if (state->chip_revcode < 26)
                rev_char = 'A' + state->chip_revcode;
        else
                rev_char = '?';

        switch (state->chip_type) {
        case 0x06:
                chip_name = "Si2161";
                state->has_dvbt = true;
                break;
        case 0x07:
                chip_name = "Si2165";
                state->has_dvbt = true;
                state->has_dvbc = true;
                break;
        default:
                dev_err(&state->client->dev, "Unsupported Silicon Labs chip (type %d, rev %d)\n",
                        state->chip_type, state->chip_revcode);
                goto nodev_error;
        }

        dev_info(&state->client->dev,
                 "Detected Silicon Labs %s-%c (type %d, rev %d)\n",
                chip_name, rev_char, state->chip_type,
                state->chip_revcode);

        strlcat(state->fe.ops.info.name, chip_name,
                sizeof(state->fe.ops.info.name));

        n = 0;
        if (state->has_dvbt) {
                state->fe.ops.delsys[n++] = SYS_DVBT;
                strlcat(state->fe.ops.info.name, " DVB-T",
                        sizeof(state->fe.ops.info.name));
        }
        if (state->has_dvbc) {
                state->fe.ops.delsys[n++] = SYS_DVBC_ANNEX_A;
                strlcat(state->fe.ops.info.name, " DVB-C",
                        sizeof(state->fe.ops.info.name));
        }

        /* return fe pointer */
        *pdata->fe = &state->fe;

        return 0;

nodev_error:
        ret = -ENODEV;
error:
        kfree(state);
        dev_dbg(&client->dev, "failed=%d\n", ret);
        return ret;
}

static int si2165_remove(struct i2c_client *client)
{
        struct si2165_state *state = i2c_get_clientdata(client);

        dev_dbg(&client->dev, "\n");

        kfree(state);
        return 0;
}

static const struct i2c_device_id si2165_id_table[] = {
        {"si2165", 0},
        {}
};
MODULE_DEVICE_TABLE(i2c, si2165_id_table);

static struct i2c_driver si2165_driver = {
        .driver = {
                .name   = "si2165",
        },
        .probe          = si2165_probe,
        .remove         = si2165_remove,
        .id_table       = si2165_id_table,
};

module_i2c_driver(si2165_driver);

MODULE_DESCRIPTION("Silicon Labs Si2165 DVB-C/-T Demodulator driver");
MODULE_AUTHOR("Matthias Schwarzott <zzam@gentoo.org>");
MODULE_LICENSE("GPL");
MODULE_FIRMWARE(SI2165_FIRMWARE_REV_D);