// SPDX-License-Identifier: GPL-2.0-only
/*
 * wm8978.c  --  WM8978 ALSA SoC Audio Codec driver
 *
 * Copyright (C) 2009-2010 Guennadi Liakhovetski <g.liakhovetski@gmx.de>
 * Copyright (C) 2007 Carlos Munoz <carlos@kenati.com>
 * Copyright 2006-2009 Wolfson Microelectronics PLC.
 * Based on wm8974 and wm8990 by Liam Girdwood <lrg@slimlogic.co.uk>
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/i2c.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/initval.h>
#include <sound/tlv.h>
#include <asm/div64.h>

#include "wm8978.h"

static const struct reg_default wm8978_reg_defaults[] = {
        { 1, 0x0000 },
        { 2, 0x0000 },
        { 3, 0x0000 },
        { 4, 0x0050 },
        { 5, 0x0000 },
        { 6, 0x0140 },
        { 7, 0x0000 },
        { 8, 0x0000 },
        { 9, 0x0000 },
        { 10, 0x0000 },
        { 11, 0x00ff },
        { 12, 0x00ff },
        { 13, 0x0000 },
        { 14, 0x0100 },
        { 15, 0x00ff },
        { 16, 0x00ff },
        { 17, 0x0000 },
        { 18, 0x012c },
        { 19, 0x002c },
        { 20, 0x002c },
        { 21, 0x002c },
        { 22, 0x002c },
        { 23, 0x0000 },
        { 24, 0x0032 },
        { 25, 0x0000 },
        { 26, 0x0000 },
        { 27, 0x0000 },
        { 28, 0x0000 },
        { 29, 0x0000 },
        { 30, 0x0000 },
        { 31, 0x0000 },
        { 32, 0x0038 },
        { 33, 0x000b },
        { 34, 0x0032 },
        { 35, 0x0000 },
        { 36, 0x0008 },
        { 37, 0x000c },
        { 38, 0x0093 },
        { 39, 0x00e9 },
        { 40, 0x0000 },
        { 41, 0x0000 },
        { 42, 0x0000 },
        { 43, 0x0000 },
        { 44, 0x0033 },
        { 45, 0x0010 },
        { 46, 0x0010 },
        { 47, 0x0100 },
        { 48, 0x0100 },
        { 49, 0x0002 },
        { 50, 0x0001 },
        { 51, 0x0001 },
        { 52, 0x0039 },
        { 53, 0x0039 },
        { 54, 0x0039 },
        { 55, 0x0039 },
        { 56, 0x0001 },
        { 57, 0x0001 },
};

static bool wm8978_volatile(struct device *dev, unsigned int reg)
{
        return reg == WM8978_RESET;
}

/* codec private data */
struct wm8978_priv {
        struct regmap *regmap;
        unsigned int f_pllout;
        unsigned int f_mclk;
        unsigned int f_256fs;
        unsigned int f_opclk;
        int mclk_idx;
        enum wm8978_sysclk_src sysclk;
};

static const char *wm8978_companding[] = {"Off", "NC", "u-law", "A-law"};
static const char *wm8978_eqmode[] = {"Capture", "Playback"};
static const char *wm8978_bw[] = {"Narrow", "Wide"};
static const char *wm8978_eq1[] = {"80Hz", "105Hz", "135Hz", "175Hz"};
static const char *wm8978_eq2[] = {"230Hz", "300Hz", "385Hz", "500Hz"};
static const char *wm8978_eq3[] = {"650Hz", "850Hz", "1.1kHz", "1.4kHz"};
static const char *wm8978_eq4[] = {"1.8kHz", "2.4kHz", "3.2kHz", "4.1kHz"};
static const char *wm8978_eq5[] = {"5.3kHz", "6.9kHz", "9kHz", "11.7kHz"};
static const char *wm8978_alc3[] = {"ALC", "Limiter"};
static const char *wm8978_alc1[] = {"Off", "Right", "Left", "Both"};

static SOC_ENUM_SINGLE_DECL(adc_compand, WM8978_COMPANDING_CONTROL, 1,
                            wm8978_companding);
static SOC_ENUM_SINGLE_DECL(dac_compand, WM8978_COMPANDING_CONTROL, 3,
                            wm8978_companding);
static SOC_ENUM_SINGLE_DECL(eqmode, WM8978_EQ1, 8, wm8978_eqmode);
static SOC_ENUM_SINGLE_DECL(eq1, WM8978_EQ1, 5, wm8978_eq1);
static SOC_ENUM_SINGLE_DECL(eq2bw, WM8978_EQ2, 8, wm8978_bw);
static SOC_ENUM_SINGLE_DECL(eq2, WM8978_EQ2, 5, wm8978_eq2);
static SOC_ENUM_SINGLE_DECL(eq3bw, WM8978_EQ3, 8, wm8978_bw);
static SOC_ENUM_SINGLE_DECL(eq3, WM8978_EQ3, 5, wm8978_eq3);
static SOC_ENUM_SINGLE_DECL(eq4bw, WM8978_EQ4, 8, wm8978_bw);
static SOC_ENUM_SINGLE_DECL(eq4, WM8978_EQ4, 5, wm8978_eq4);
static SOC_ENUM_SINGLE_DECL(eq5, WM8978_EQ5, 5, wm8978_eq5);
static SOC_ENUM_SINGLE_DECL(alc3, WM8978_ALC_CONTROL_3, 8, wm8978_alc3);
static SOC_ENUM_SINGLE_DECL(alc1, WM8978_ALC_CONTROL_1, 7, wm8978_alc1);

static const DECLARE_TLV_DB_SCALE(digital_tlv, -12750, 50, 1);
static const DECLARE_TLV_DB_SCALE(eq_tlv, -1200, 100, 0);
static const DECLARE_TLV_DB_SCALE(inpga_tlv, -1200, 75, 0);
static const DECLARE_TLV_DB_SCALE(spk_tlv, -5700, 100, 0);
static const DECLARE_TLV_DB_SCALE(boost_tlv, -1500, 300, 1);
static const DECLARE_TLV_DB_SCALE(limiter_tlv, 0, 100, 0);

static const struct snd_kcontrol_new wm8978_snd_controls[] = {

        SOC_SINGLE("Digital Loopback Switch",
                WM8978_COMPANDING_CONTROL, 0, 1, 0),

        SOC_ENUM("ADC Companding", adc_compand),
        SOC_ENUM("DAC Companding", dac_compand),

        SOC_DOUBLE("DAC Inversion Switch", WM8978_DAC_CONTROL, 0, 1, 1, 0),

        SOC_DOUBLE_R_TLV("PCM Volume",
                WM8978_LEFT_DAC_DIGITAL_VOLUME, WM8978_RIGHT_DAC_DIGITAL_VOLUME,
                0, 255, 0, digital_tlv),

        SOC_SINGLE("High Pass Filter Switch", WM8978_ADC_CONTROL, 8, 1, 0),
        SOC_SINGLE("High Pass Cut Off", WM8978_ADC_CONTROL, 4, 7, 0),
        SOC_DOUBLE("ADC Inversion Switch", WM8978_ADC_CONTROL, 0, 1, 1, 0),

        SOC_DOUBLE_R_TLV("ADC Volume",
                WM8978_LEFT_ADC_DIGITAL_VOLUME, WM8978_RIGHT_ADC_DIGITAL_VOLUME,
                0, 255, 0, digital_tlv),

        SOC_ENUM("Equaliser Function", eqmode),
        SOC_ENUM("EQ1 Cut Off", eq1),
        SOC_SINGLE_TLV("EQ1 Volume", WM8978_EQ1,  0, 24, 1, eq_tlv),

        SOC_ENUM("Equaliser EQ2 Bandwidth", eq2bw),
        SOC_ENUM("EQ2 Cut Off", eq2),
        SOC_SINGLE_TLV("EQ2 Volume", WM8978_EQ2,  0, 24, 1, eq_tlv),

        SOC_ENUM("Equaliser EQ3 Bandwidth", eq3bw),
        SOC_ENUM("EQ3 Cut Off", eq3),
        SOC_SINGLE_TLV("EQ3 Volume", WM8978_EQ3,  0, 24, 1, eq_tlv),

        SOC_ENUM("Equaliser EQ4 Bandwidth", eq4bw),
        SOC_ENUM("EQ4 Cut Off", eq4),
        SOC_SINGLE_TLV("EQ4 Volume", WM8978_EQ4,  0, 24, 1, eq_tlv),

        SOC_ENUM("EQ5 Cut Off", eq5),
        SOC_SINGLE_TLV("EQ5 Volume", WM8978_EQ5, 0, 24, 1, eq_tlv),

        SOC_SINGLE("DAC Playback Limiter Switch",
                WM8978_DAC_LIMITER_1, 8, 1, 0),
        SOC_SINGLE("DAC Playback Limiter Decay",
                WM8978_DAC_LIMITER_1, 4, 15, 0),
        SOC_SINGLE("DAC Playback Limiter Attack",
                WM8978_DAC_LIMITER_1, 0, 15, 0),

        SOC_SINGLE("DAC Playback Limiter Threshold",
                WM8978_DAC_LIMITER_2, 4, 7, 0),
        SOC_SINGLE_TLV("DAC Playback Limiter Volume",
                WM8978_DAC_LIMITER_2, 0, 12, 0, limiter_tlv),

        SOC_ENUM("ALC Enable Switch", alc1),
        SOC_SINGLE("ALC Capture Min Gain", WM8978_ALC_CONTROL_1, 0, 7, 0),
        SOC_SINGLE("ALC Capture Max Gain", WM8978_ALC_CONTROL_1, 3, 7, 0),

        SOC_SINGLE("ALC Capture Hold", WM8978_ALC_CONTROL_2, 4, 10, 0),
        SOC_SINGLE("ALC Capture Target", WM8978_ALC_CONTROL_2, 0, 15, 0),

        SOC_ENUM("ALC Capture Mode", alc3),
        SOC_SINGLE("ALC Capture Decay", WM8978_ALC_CONTROL_3, 4, 10, 0),
        SOC_SINGLE("ALC Capture Attack", WM8978_ALC_CONTROL_3, 0, 10, 0),

        SOC_SINGLE("ALC Capture Noise Gate Switch", WM8978_NOISE_GATE, 3, 1, 0),
        SOC_SINGLE("ALC Capture Noise Gate Threshold",
                WM8978_NOISE_GATE, 0, 7, 0),

        SOC_DOUBLE_R("Capture PGA ZC Switch",
                WM8978_LEFT_INP_PGA_CONTROL, WM8978_RIGHT_INP_PGA_CONTROL,
                7, 1, 0),

        /* OUT1 - Headphones */
        SOC_DOUBLE_R("Headphone Playback ZC Switch",
                WM8978_LOUT1_HP_CONTROL, WM8978_ROUT1_HP_CONTROL, 7, 1, 0),

        SOC_DOUBLE_R_TLV("Headphone Playback Volume",
                WM8978_LOUT1_HP_CONTROL, WM8978_ROUT1_HP_CONTROL,
                0, 63, 0, spk_tlv),

        /* OUT2 - Speakers */
        SOC_DOUBLE_R("Speaker Playback ZC Switch",
                WM8978_LOUT2_SPK_CONTROL, WM8978_ROUT2_SPK_CONTROL, 7, 1, 0),

        SOC_DOUBLE_R_TLV("Speaker Playback Volume",
                WM8978_LOUT2_SPK_CONTROL, WM8978_ROUT2_SPK_CONTROL,
                0, 63, 0, spk_tlv),

        /* OUT3/4 - Line Output */
        SOC_DOUBLE_R("Line Playback Switch",
                WM8978_OUT3_MIXER_CONTROL, WM8978_OUT4_MIXER_CONTROL, 6, 1, 1),

        /* Mixer #3: Boost (Input) mixer */
        SOC_DOUBLE_R("PGA Boost (+20dB)",
                WM8978_LEFT_ADC_BOOST_CONTROL, WM8978_RIGHT_ADC_BOOST_CONTROL,
                8, 1, 0),
        SOC_DOUBLE_R_TLV("L2/R2 Boost Volume",
                WM8978_LEFT_ADC_BOOST_CONTROL, WM8978_RIGHT_ADC_BOOST_CONTROL,
                4, 7, 0, boost_tlv),
        SOC_DOUBLE_R_TLV("Aux Boost Volume",
                WM8978_LEFT_ADC_BOOST_CONTROL, WM8978_RIGHT_ADC_BOOST_CONTROL,
                0, 7, 0, boost_tlv),

        /* Input PGA volume */
        SOC_DOUBLE_R_TLV("Input PGA Volume",
                WM8978_LEFT_INP_PGA_CONTROL, WM8978_RIGHT_INP_PGA_CONTROL,
                0, 63, 0, inpga_tlv),

        /* Headphone */
        SOC_DOUBLE_R("Headphone Switch",
                WM8978_LOUT1_HP_CONTROL, WM8978_ROUT1_HP_CONTROL, 6, 1, 1),

        /* Speaker */
        SOC_DOUBLE_R("Speaker Switch",
                WM8978_LOUT2_SPK_CONTROL, WM8978_ROUT2_SPK_CONTROL, 6, 1, 1),

        /* DAC / ADC oversampling */
        SOC_SINGLE("DAC 128x Oversampling Switch", WM8978_DAC_CONTROL,
                   5, 1, 0),
        SOC_SINGLE("ADC 128x Oversampling Switch", WM8978_ADC_CONTROL,
                   5, 1, 0),
};

/* Mixer #1: Output (OUT1, OUT2) Mixer: mix AUX, Input mixer output and DAC */
static const struct snd_kcontrol_new wm8978_left_out_mixer[] = {
        SOC_DAPM_SINGLE("Line Bypass Switch", WM8978_LEFT_MIXER_CONTROL, 1, 1, 0),
        SOC_DAPM_SINGLE("Aux Playback Switch", WM8978_LEFT_MIXER_CONTROL, 5, 1, 0),
        SOC_DAPM_SINGLE("PCM Playback Switch", WM8978_LEFT_MIXER_CONTROL, 0, 1, 0),
};

static const struct snd_kcontrol_new wm8978_right_out_mixer[] = {
        SOC_DAPM_SINGLE("Line Bypass Switch", WM8978_RIGHT_MIXER_CONTROL, 1, 1, 0),
        SOC_DAPM_SINGLE("Aux Playback Switch", WM8978_RIGHT_MIXER_CONTROL, 5, 1, 0),
        SOC_DAPM_SINGLE("PCM Playback Switch", WM8978_RIGHT_MIXER_CONTROL, 0, 1, 0),
};

/* OUT3/OUT4 Mixer not implemented */

/* Mixer #2: Input PGA Mute */
static const struct snd_kcontrol_new wm8978_left_input_mixer[] = {
        SOC_DAPM_SINGLE("L2 Switch", WM8978_INPUT_CONTROL, 2, 1, 0),
        SOC_DAPM_SINGLE("MicN Switch", WM8978_INPUT_CONTROL, 1, 1, 0),
        SOC_DAPM_SINGLE("MicP Switch", WM8978_INPUT_CONTROL, 0, 1, 0),
};
static const struct snd_kcontrol_new wm8978_right_input_mixer[] = {
        SOC_DAPM_SINGLE("R2 Switch", WM8978_INPUT_CONTROL, 6, 1, 0),
        SOC_DAPM_SINGLE("MicN Switch", WM8978_INPUT_CONTROL, 5, 1, 0),
        SOC_DAPM_SINGLE("MicP Switch", WM8978_INPUT_CONTROL, 4, 1, 0),
};

static const struct snd_soc_dapm_widget wm8978_dapm_widgets[] = {
        SND_SOC_DAPM_DAC("Left DAC", "Left HiFi Playback",
                         WM8978_POWER_MANAGEMENT_3, 0, 0),
        SND_SOC_DAPM_DAC("Right DAC", "Right HiFi Playback",
                         WM8978_POWER_MANAGEMENT_3, 1, 0),
        SND_SOC_DAPM_ADC("Left ADC", "Left HiFi Capture",
                         WM8978_POWER_MANAGEMENT_2, 0, 0),
        SND_SOC_DAPM_ADC("Right ADC", "Right HiFi Capture",
                         WM8978_POWER_MANAGEMENT_2, 1, 0),

        /* Mixer #1: OUT1,2 */
        SOC_MIXER_ARRAY("Left Output Mixer", WM8978_POWER_MANAGEMENT_3,
                        2, 0, wm8978_left_out_mixer),
        SOC_MIXER_ARRAY("Right Output Mixer", WM8978_POWER_MANAGEMENT_3,
                        3, 0, wm8978_right_out_mixer),

        SOC_MIXER_ARRAY("Left Input Mixer", WM8978_POWER_MANAGEMENT_2,
                        2, 0, wm8978_left_input_mixer),
        SOC_MIXER_ARRAY("Right Input Mixer", WM8978_POWER_MANAGEMENT_2,
                        3, 0, wm8978_right_input_mixer),

        SND_SOC_DAPM_PGA("Left Boost Mixer", WM8978_POWER_MANAGEMENT_2,
                         4, 0, NULL, 0),
        SND_SOC_DAPM_PGA("Right Boost Mixer", WM8978_POWER_MANAGEMENT_2,
                         5, 0, NULL, 0),

        SND_SOC_DAPM_PGA("Left Capture PGA", WM8978_LEFT_INP_PGA_CONTROL,
                         6, 1, NULL, 0),
        SND_SOC_DAPM_PGA("Right Capture PGA", WM8978_RIGHT_INP_PGA_CONTROL,
                         6, 1, NULL, 0),

        SND_SOC_DAPM_PGA("Left Headphone Out", WM8978_POWER_MANAGEMENT_2,
                         7, 0, NULL, 0),
        SND_SOC_DAPM_PGA("Right Headphone Out", WM8978_POWER_MANAGEMENT_2,
                         8, 0, NULL, 0),

        SND_SOC_DAPM_PGA("Left Speaker Out", WM8978_POWER_MANAGEMENT_3,
                         6, 0, NULL, 0),
        SND_SOC_DAPM_PGA("Right Speaker Out", WM8978_POWER_MANAGEMENT_3,
                         5, 0, NULL, 0),

        SND_SOC_DAPM_MIXER("OUT4 VMID", WM8978_POWER_MANAGEMENT_3,
                           8, 0, NULL, 0),

        SND_SOC_DAPM_MICBIAS("Mic Bias", WM8978_POWER_MANAGEMENT_1, 4, 0),

        SND_SOC_DAPM_INPUT("LMICN"),
        SND_SOC_DAPM_INPUT("LMICP"),
        SND_SOC_DAPM_INPUT("RMICN"),
        SND_SOC_DAPM_INPUT("RMICP"),
        SND_SOC_DAPM_INPUT("LAUX"),
        SND_SOC_DAPM_INPUT("RAUX"),
        SND_SOC_DAPM_INPUT("L2"),
        SND_SOC_DAPM_INPUT("R2"),
        SND_SOC_DAPM_OUTPUT("LHP"),
        SND_SOC_DAPM_OUTPUT("RHP"),
        SND_SOC_DAPM_OUTPUT("LSPK"),
        SND_SOC_DAPM_OUTPUT("RSPK"),
};

static const struct snd_soc_dapm_route wm8978_dapm_routes[] = {
        /* Output mixer */
        {"Right Output Mixer", "PCM Playback Switch", "Right DAC"},
        {"Right Output Mixer", "Aux Playback Switch", "RAUX"},
        {"Right Output Mixer", "Line Bypass Switch", "Right Boost Mixer"},

        {"Left Output Mixer", "PCM Playback Switch", "Left DAC"},
        {"Left Output Mixer", "Aux Playback Switch", "LAUX"},
        {"Left Output Mixer", "Line Bypass Switch", "Left Boost Mixer"},

        /* Outputs */
        {"Right Headphone Out", NULL, "Right Output Mixer"},
        {"RHP", NULL, "Right Headphone Out"},

        {"Left Headphone Out", NULL, "Left Output Mixer"},
        {"LHP", NULL, "Left Headphone Out"},

        {"Right Speaker Out", NULL, "Right Output Mixer"},
        {"RSPK", NULL, "Right Speaker Out"},

        {"Left Speaker Out", NULL, "Left Output Mixer"},
        {"LSPK", NULL, "Left Speaker Out"},

        /* Boost Mixer */
        {"Right ADC", NULL, "Right Boost Mixer"},

        {"Right Boost Mixer", NULL, "RAUX"},
        {"Right Boost Mixer", NULL, "Right Capture PGA"},
        {"Right Boost Mixer", NULL, "R2"},

        {"Left ADC", NULL, "Left Boost Mixer"},

        {"Left Boost Mixer", NULL, "LAUX"},
        {"Left Boost Mixer", NULL, "Left Capture PGA"},
        {"Left Boost Mixer", NULL, "L2"},

        /* Input PGA */
        {"Right Capture PGA", NULL, "Right Input Mixer"},
        {"Left Capture PGA", NULL, "Left Input Mixer"},

        {"Right Input Mixer", "R2 Switch", "R2"},
        {"Right Input Mixer", "MicN Switch", "RMICN"},
        {"Right Input Mixer", "MicP Switch", "RMICP"},

        {"Left Input Mixer", "L2 Switch", "L2"},
        {"Left Input Mixer", "MicN Switch", "LMICN"},
        {"Left Input Mixer", "MicP Switch", "LMICP"},
};

/* PLL divisors */
struct wm8978_pll_div {
        u32 k;
        u8 n;
        u8 div2;
};

#define FIXED_PLL_SIZE (1 << 24)

static void pll_factors(struct snd_soc_component *component,
                struct wm8978_pll_div *pll_div, unsigned int target, unsigned int source)
{
        u64 k_part;
        unsigned int k, n_div, n_mod;

        n_div = target / source;
        if (n_div < 6) {
                source >>= 1;
                pll_div->div2 = 1;
                n_div = target / source;
        } else {
                pll_div->div2 = 0;
        }

        if (n_div < 6 || n_div > 12)
                dev_warn(component->dev,
                         "WM8978 N value exceeds recommended range! N = %u\n",
                         n_div);

        pll_div->n = n_div;
        n_mod = target - source * n_div;
        k_part = FIXED_PLL_SIZE * (long long)n_mod + source / 2;

        do_div(k_part, source);

        k = k_part & 0xFFFFFFFF;

        pll_div->k = k;
}

/* MCLK dividers */
static const int mclk_numerator[]       = {1, 3, 2, 3, 4, 6, 8, 12};
static const int mclk_denominator[]     = {1, 2, 1, 1, 1, 1, 1, 1};

/*
 * find index >= idx, such that, for a given f_out,
 * 3 * f_mclk / 4 <= f_PLLOUT < 13 * f_mclk / 4
 * f_out can be f_256fs or f_opclk, currently only used for f_256fs. Can be
 * generalised for f_opclk with suitable coefficient arrays, but currently
 * the OPCLK divisor is calculated directly, not iteratively.
 */
static int wm8978_enum_mclk(unsigned int f_out, unsigned int f_mclk,
                            unsigned int *f_pllout)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(mclk_numerator); i++) {
                unsigned int f_pllout_x4 = 4 * f_out * mclk_numerator[i] /
                        mclk_denominator[i];
                if (3 * f_mclk <= f_pllout_x4 && f_pllout_x4 < 13 * f_mclk) {
                        *f_pllout = f_pllout_x4 / 4;
                        return i;
                }
        }

        return -EINVAL;
}

/*
 * Calculate internal frequencies and dividers, according to Figure 40
 * "PLL and Clock Select Circuit" in WM8978 datasheet Rev. 2.6
 */
static int wm8978_configure_pll(struct snd_soc_component *component)
{
        struct wm8978_priv *wm8978 = snd_soc_component_get_drvdata(component);
        struct wm8978_pll_div pll_div;
        unsigned int f_opclk = wm8978->f_opclk, f_mclk = wm8978->f_mclk,
                f_256fs = wm8978->f_256fs;
        unsigned int f2;

        if (!f_mclk)
                return -EINVAL;

        if (f_opclk) {
                unsigned int opclk_div;
                /* Cannot set up MCLK divider now, do later */
                wm8978->mclk_idx = -1;

                /*
                 * The user needs OPCLK. Choose OPCLKDIV to put
                 * 6 <= R = f2 / f1 < 13, 1 <= OPCLKDIV <= 4.
                 * f_opclk = f_mclk * prescale * R / 4 / OPCLKDIV, where
                 * prescale = 1, or prescale = 2. Prescale is calculated inside
                 * pll_factors(). We have to select f_PLLOUT, such that
                 * f_mclk * 3 / 4 <= f_PLLOUT < f_mclk * 13 / 4. Must be
                 * f_mclk * 3 / 16 <= f_opclk < f_mclk * 13 / 4.
                 */
                if (16 * f_opclk < 3 * f_mclk || 4 * f_opclk >= 13 * f_mclk)
                        return -EINVAL;

                if (4 * f_opclk < 3 * f_mclk)
                        /* Have to use OPCLKDIV */
                        opclk_div = DIV_ROUND_UP(3 * f_mclk / 4, f_opclk);
                else
                        opclk_div = 1;

                dev_dbg(component->dev, "%s: OPCLKDIV=%d\n", __func__, opclk_div);

                snd_soc_component_update_bits(component, WM8978_GPIO_CONTROL, 0x30,
                                    (opclk_div - 1) << 4);

                wm8978->f_pllout = f_opclk * opclk_div;
        } else if (f_256fs) {
                /*
                 * Not using OPCLK, but PLL is used for the codec, choose R:
                 * 6 <= R = f2 / f1 < 13, to put 1 <= MCLKDIV <= 12.
                 * f_256fs = f_mclk * prescale * R / 4 / MCLKDIV, where
                 * prescale = 1, or prescale = 2. Prescale is calculated inside
                 * pll_factors(). We have to select f_PLLOUT, such that
                 * f_mclk * 3 / 4 <= f_PLLOUT < f_mclk * 13 / 4. Must be
                 * f_mclk * 3 / 48 <= f_256fs < f_mclk * 13 / 4. This means MCLK
                 * must be 3.781MHz <= f_MCLK <= 32.768MHz
                 */
                int idx = wm8978_enum_mclk(f_256fs, f_mclk, &wm8978->f_pllout);
                if (idx < 0)
                        return idx;

                wm8978->mclk_idx = idx;
        } else {
                return -EINVAL;
        }

        f2 = wm8978->f_pllout * 4;

        dev_dbg(component->dev, "%s: f_MCLK=%uHz, f_PLLOUT=%uHz\n", __func__,
                wm8978->f_mclk, wm8978->f_pllout);

        pll_factors(component, &pll_div, f2, wm8978->f_mclk);

        dev_dbg(component->dev, "%s: calculated PLL N=0x%x, K=0x%x, div2=%d\n",
                __func__, pll_div.n, pll_div.k, pll_div.div2);

        /* Turn PLL off for configuration... */
        snd_soc_component_update_bits(component, WM8978_POWER_MANAGEMENT_1, 0x20, 0);

        snd_soc_component_write(component, WM8978_PLL_N, (pll_div.div2 << 4) | pll_div.n);
        snd_soc_component_write(component, WM8978_PLL_K1, pll_div.k >> 18);
        snd_soc_component_write(component, WM8978_PLL_K2, (pll_div.k >> 9) & 0x1ff);
        snd_soc_component_write(component, WM8978_PLL_K3, pll_div.k & 0x1ff);

        /* ...and on again */
        snd_soc_component_update_bits(component, WM8978_POWER_MANAGEMENT_1, 0x20, 0x20);

        if (f_opclk)
                /* Output PLL (OPCLK) to GPIO1 */
                snd_soc_component_update_bits(component, WM8978_GPIO_CONTROL, 7, 4);

        return 0;
}

/*
 * Configure WM8978 clock dividers.
 */
static int wm8978_set_dai_clkdiv(struct snd_soc_dai *codec_dai,
                                 int div_id, int div)
{
        struct snd_soc_component *component = codec_dai->component;
        struct wm8978_priv *wm8978 = snd_soc_component_get_drvdata(component);
        int ret = 0;

        switch (div_id) {
        case WM8978_OPCLKRATE:
                wm8978->f_opclk = div;

                if (wm8978->f_mclk)
                        /*
                         * We know the MCLK frequency, the user has requested
                         * OPCLK, configure the PLL based on that and start it
                         * and OPCLK immediately. We will configure PLL to match
                         * user-requested OPCLK frquency as good as possible.
                         * In fact, it is likely, that matching the sampling
                         * rate, when it becomes known, is more important, and
                         * we will not be reconfiguring PLL then, because we
                         * must not interrupt OPCLK. But it should be fine,
                         * because typically the user will request OPCLK to run
                         * at 256fs or 512fs, and for these cases we will also
                         * find an exact MCLK divider configuration - it will
                         * be equal to or double the OPCLK divisor.
                         */
                        ret = wm8978_configure_pll(component);
                break;
        case WM8978_BCLKDIV:
                if (div & ~0x1c)
                        return -EINVAL;
                snd_soc_component_update_bits(component, WM8978_CLOCKING, 0x1c, div);
                break;
        default:
                return -EINVAL;
        }

        dev_dbg(component->dev, "%s: ID %d, value %u\n", __func__, div_id, div);

        return ret;
}

/*
 * @freq:       when .set_pll() us not used, freq is codec MCLK input frequency
 */
static int wm8978_set_dai_sysclk(struct snd_soc_dai *codec_dai, int clk_id,
                                 unsigned int freq, int dir)
{
        struct snd_soc_component *component = codec_dai->component;
        struct wm8978_priv *wm8978 = snd_soc_component_get_drvdata(component);
        int ret = 0;

        dev_dbg(component->dev, "%s: ID %d, freq %u\n", __func__, clk_id, freq);

        if (freq) {
                wm8978->f_mclk = freq;

                /* Even if MCLK is used for system clock, might have to drive OPCLK */
                if (wm8978->f_opclk)
                        ret = wm8978_configure_pll(component);

                /* Our sysclk is fixed to 256 * fs, will configure in .hw_params()  */

                if (!ret)
                        wm8978->sysclk = clk_id;
        }

        if (wm8978->sysclk == WM8978_PLL && (!freq || clk_id == WM8978_MCLK)) {
                /* Clock CODEC directly from MCLK */
                snd_soc_component_update_bits(component, WM8978_CLOCKING, 0x100, 0);

                /* GPIO1 into default mode as input - before configuring PLL */
                snd_soc_component_update_bits(component, WM8978_GPIO_CONTROL, 7, 0);

                /* Turn off PLL */
                snd_soc_component_update_bits(component, WM8978_POWER_MANAGEMENT_1, 0x20, 0);
                wm8978->sysclk = WM8978_MCLK;
                wm8978->f_pllout = 0;
                wm8978->f_opclk = 0;
        }

        return ret;
}

/*
 * Set ADC and Voice DAC format.
 */
static int wm8978_set_dai_fmt(struct snd_soc_dai *codec_dai, unsigned int fmt)
{
        struct snd_soc_component *component = codec_dai->component;
        /*
         * BCLK polarity mask = 0x100, LRC clock polarity mask = 0x80,
         * Data Format mask = 0x18: all will be calculated anew
         */
        u16 iface = snd_soc_component_read(component, WM8978_AUDIO_INTERFACE) & ~0x198;
        u16 clk = snd_soc_component_read(component, WM8978_CLOCKING);

        dev_dbg(component->dev, "%s\n", __func__);

        /* set master/slave audio interface */
        switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
        case SND_SOC_DAIFMT_CBP_CFP:
                clk |= 1;
                break;
        case SND_SOC_DAIFMT_CBC_CFC:
                clk &= ~1;
                break;
        default:
                return -EINVAL;
        }

        /* interface format */
        switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
        case SND_SOC_DAIFMT_I2S:
                iface |= 0x10;
                break;
        case SND_SOC_DAIFMT_RIGHT_J:
                break;
        case SND_SOC_DAIFMT_LEFT_J:
                iface |= 0x8;
                break;
        case SND_SOC_DAIFMT_DSP_A:
                iface |= 0x18;
                break;
        default:
                return -EINVAL;
        }

        /* clock inversion */
        switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
        case SND_SOC_DAIFMT_NB_NF:
                break;
        case SND_SOC_DAIFMT_IB_IF:
                iface |= 0x180;
                break;
        case SND_SOC_DAIFMT_IB_NF:
                iface |= 0x100;
                break;
        case SND_SOC_DAIFMT_NB_IF:
                iface |= 0x80;
                break;
        default:
                return -EINVAL;
        }

        snd_soc_component_write(component, WM8978_AUDIO_INTERFACE, iface);
        snd_soc_component_write(component, WM8978_CLOCKING, clk);

        return 0;
}

/*
 * Set PCM DAI bit size and sample rate.
 */
static int wm8978_hw_params(struct snd_pcm_substream *substream,
                            struct snd_pcm_hw_params *params,
                            struct snd_soc_dai *dai)
{
        struct snd_soc_component *component = dai->component;
        struct wm8978_priv *wm8978 = snd_soc_component_get_drvdata(component);
        /* Word length mask = 0x60 */
        u16 iface_ctl = snd_soc_component_read(component, WM8978_AUDIO_INTERFACE) & ~0x60;
        /* Sampling rate mask = 0xe (for filters) */
        u16 add_ctl = snd_soc_component_read(component, WM8978_ADDITIONAL_CONTROL) & ~0xe;
        u16 clking = snd_soc_component_read(component, WM8978_CLOCKING);
        enum wm8978_sysclk_src current_clk_id = (clking & 0x100) ?
                WM8978_PLL : WM8978_MCLK;
        unsigned int f_sel, diff, diff_best = INT_MAX;
        int i, best = 0;

        if (!wm8978->f_mclk)
                return -EINVAL;

        /* bit size */
        switch (params_width(params)) {
        case 16:
                break;
        case 20:
                iface_ctl |= 0x20;
                break;
        case 24:
                iface_ctl |= 0x40;
                break;
        case 32:
                iface_ctl |= 0x60;
                break;
        }

        /* filter coefficient */
        switch (params_rate(params)) {
        case 8000:
                add_ctl |= 0x5 << 1;
                break;
        case 11025:
                add_ctl |= 0x4 << 1;
                break;
        case 16000:
                add_ctl |= 0x3 << 1;
                break;
        case 22050:
                add_ctl |= 0x2 << 1;
                break;
        case 32000:
                add_ctl |= 0x1 << 1;
                break;
        case 44100:
        case 48000:
                break;
        }

        /* Sampling rate is known now, can configure the MCLK divider */
        wm8978->f_256fs = params_rate(params) * 256;

        if (wm8978->sysclk == WM8978_MCLK) {
                wm8978->mclk_idx = -1;
                f_sel = wm8978->f_mclk;
        } else {
                if (!wm8978->f_opclk) {
                        /* We only enter here, if OPCLK is not used */
                        int ret = wm8978_configure_pll(component);
                        if (ret < 0)
                                return ret;
                }
                f_sel = wm8978->f_pllout;
        }

        if (wm8978->mclk_idx < 0) {
                /* Either MCLK is used directly, or OPCLK is used */
                if (f_sel < wm8978->f_256fs || f_sel > 12 * wm8978->f_256fs)
                        return -EINVAL;

                for (i = 0; i < ARRAY_SIZE(mclk_numerator); i++) {
                        diff = abs(wm8978->f_256fs * 3 -
                                   f_sel * 3 * mclk_denominator[i] / mclk_numerator[i]);

                        if (diff < diff_best) {
                                diff_best = diff;
                                best = i;
                        }

                        if (!diff)
                                break;
                }
        } else {
                /* OPCLK not used, codec driven by PLL */
                best = wm8978->mclk_idx;
                diff = 0;
        }

        if (diff)
                dev_warn(component->dev, "Imprecise sampling rate: %uHz%s\n",
                        f_sel * mclk_denominator[best] / mclk_numerator[best] / 256,
                        wm8978->sysclk == WM8978_MCLK ?
                        ", consider using PLL" : "");

        dev_dbg(component->dev, "%s: width %d, rate %u, MCLK divisor #%d\n", __func__,
                params_width(params), params_rate(params), best);

        /* MCLK divisor mask = 0xe0 */
        snd_soc_component_update_bits(component, WM8978_CLOCKING, 0xe0, best << 5);

        snd_soc_component_write(component, WM8978_AUDIO_INTERFACE, iface_ctl);
        snd_soc_component_write(component, WM8978_ADDITIONAL_CONTROL, add_ctl);

        if (wm8978->sysclk != current_clk_id) {
                if (wm8978->sysclk == WM8978_PLL)
                        /* Run CODEC from PLL instead of MCLK */
                        snd_soc_component_update_bits(component, WM8978_CLOCKING,
                                            0x100, 0x100);
                else
                        /* Clock CODEC directly from MCLK */
                        snd_soc_component_update_bits(component, WM8978_CLOCKING, 0x100, 0);
        }

        return 0;
}

static int wm8978_mute(struct snd_soc_dai *dai, int mute, int direction)
{
        struct snd_soc_component *component = dai->component;

        dev_dbg(component->dev, "%s: %d\n", __func__, mute);

        if (mute)
                snd_soc_component_update_bits(component, WM8978_DAC_CONTROL, 0x40, 0x40);
        else
                snd_soc_component_update_bits(component, WM8978_DAC_CONTROL, 0x40, 0);

        return 0;
}

static int wm8978_set_bias_level(struct snd_soc_component *component,
                                 enum snd_soc_bias_level level)
{
        struct snd_soc_dapm_context *dapm = snd_soc_component_to_dapm(component);
        u16 power1 = snd_soc_component_read(component, WM8978_POWER_MANAGEMENT_1) & ~3;

        switch (level) {
        case SND_SOC_BIAS_ON:
        case SND_SOC_BIAS_PREPARE:
                power1 |= 1;  /* VMID 75k */
                snd_soc_component_write(component, WM8978_POWER_MANAGEMENT_1, power1);
                break;
        case SND_SOC_BIAS_STANDBY:
                /* bit 3: enable bias, bit 2: enable I/O tie off buffer */
                power1 |= 0xc;

                if (snd_soc_dapm_get_bias_level(dapm) == SND_SOC_BIAS_OFF) {
                        /* Initial cap charge at VMID 5k */
                        snd_soc_component_write(component, WM8978_POWER_MANAGEMENT_1,
                                      power1 | 0x3);
                        mdelay(100);
                }

                power1 |= 0x2;  /* VMID 500k */
                snd_soc_component_write(component, WM8978_POWER_MANAGEMENT_1, power1);
                break;
        case SND_SOC_BIAS_OFF:
                /* Preserve PLL - OPCLK may be used by someone */
                snd_soc_component_update_bits(component, WM8978_POWER_MANAGEMENT_1, ~0x20, 0);
                snd_soc_component_write(component, WM8978_POWER_MANAGEMENT_2, 0);
                snd_soc_component_write(component, WM8978_POWER_MANAGEMENT_3, 0);
                break;
        }

        dev_dbg(component->dev, "%s: %d, %x\n", __func__, level, power1);

        return 0;
}

#define WM8978_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE | \
        SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE)

static const struct snd_soc_dai_ops wm8978_dai_ops = {
        .hw_params      = wm8978_hw_params,
        .mute_stream    = wm8978_mute,
        .set_fmt        = wm8978_set_dai_fmt,
        .set_clkdiv     = wm8978_set_dai_clkdiv,
        .set_sysclk     = wm8978_set_dai_sysclk,
        .no_capture_mute = 1,
};

/* Also supports 12kHz */
static struct snd_soc_dai_driver wm8978_dai = {
        .name = "wm8978-hifi",
        .playback = {
                .stream_name = "Playback",
                .channels_min = 1,
                .channels_max = 2,
                .rates = SNDRV_PCM_RATE_8000_48000,
                .formats = WM8978_FORMATS,
        },
        .capture = {
                .stream_name = "Capture",
                .channels_min = 1,
                .channels_max = 2,
                .rates = SNDRV_PCM_RATE_8000_48000,
                .formats = WM8978_FORMATS,
        },
        .ops = &wm8978_dai_ops,
        .symmetric_rate = 1,
};

static int wm8978_suspend(struct snd_soc_component *component)
{
        struct wm8978_priv *wm8978 = snd_soc_component_get_drvdata(component);
        struct snd_soc_dapm_context *dapm = snd_soc_component_to_dapm(component);

        snd_soc_dapm_force_bias_level(dapm, SND_SOC_BIAS_OFF);
        /* Also switch PLL off */
        snd_soc_component_write(component, WM8978_POWER_MANAGEMENT_1, 0);

        regcache_mark_dirty(wm8978->regmap);

        return 0;
}

static int wm8978_resume(struct snd_soc_component *component)
{
        struct wm8978_priv *wm8978 = snd_soc_component_get_drvdata(component);
        struct snd_soc_dapm_context *dapm = snd_soc_component_to_dapm(component);

        /* Sync reg_cache with the hardware */
        regcache_sync(wm8978->regmap);

        snd_soc_dapm_force_bias_level(dapm, SND_SOC_BIAS_STANDBY);

        if (wm8978->f_pllout)
                /* Switch PLL on */
                snd_soc_component_update_bits(component, WM8978_POWER_MANAGEMENT_1, 0x20, 0x20);

        return 0;
}

/*
 * These registers contain an "update" bit - bit 8. This means, for example,
 * that one can write new DAC digital volume for both channels, but only when
 * the update bit is set, will also the volume be updated - simultaneously for
 * both channels.
 */
static const int update_reg[] = {
        WM8978_LEFT_DAC_DIGITAL_VOLUME,
        WM8978_RIGHT_DAC_DIGITAL_VOLUME,
        WM8978_LEFT_ADC_DIGITAL_VOLUME,
        WM8978_RIGHT_ADC_DIGITAL_VOLUME,
        WM8978_LEFT_INP_PGA_CONTROL,
        WM8978_RIGHT_INP_PGA_CONTROL,
        WM8978_LOUT1_HP_CONTROL,
        WM8978_ROUT1_HP_CONTROL,
        WM8978_LOUT2_SPK_CONTROL,
        WM8978_ROUT2_SPK_CONTROL,
};

static int wm8978_probe(struct snd_soc_component *component)
{
        struct wm8978_priv *wm8978 = snd_soc_component_get_drvdata(component);
        int i;

        /*
         * Set default system clock to PLL, it is more precise, this is also the
         * default hardware setting
         */
        wm8978->sysclk = WM8978_PLL;

        /*
         * Set the update bit in all registers, that have one. This way all
         * writes to those registers will also cause the update bit to be
         * written.
         */
        for (i = 0; i < ARRAY_SIZE(update_reg); i++)
                snd_soc_component_update_bits(component, update_reg[i], 0x100, 0x100);

        return 0;
}

static const struct snd_soc_component_driver soc_component_dev_wm8978 = {
        .probe                  = wm8978_probe,
        .suspend                = wm8978_suspend,
        .resume                 = wm8978_resume,
        .set_bias_level         = wm8978_set_bias_level,
        .controls               = wm8978_snd_controls,
        .num_controls           = ARRAY_SIZE(wm8978_snd_controls),
        .dapm_widgets           = wm8978_dapm_widgets,
        .num_dapm_widgets       = ARRAY_SIZE(wm8978_dapm_widgets),
        .dapm_routes            = wm8978_dapm_routes,
        .num_dapm_routes        = ARRAY_SIZE(wm8978_dapm_routes),
        .idle_bias_on           = 1,
        .use_pmdown_time        = 1,
        .endianness             = 1,
};

static const struct regmap_config wm8978_regmap_config = {
        .reg_bits = 7,
        .val_bits = 9,

        .max_register = WM8978_MAX_REGISTER,
        .volatile_reg = wm8978_volatile,

        .cache_type = REGCACHE_MAPLE,
        .reg_defaults = wm8978_reg_defaults,
        .num_reg_defaults = ARRAY_SIZE(wm8978_reg_defaults),
};

static int wm8978_i2c_probe(struct i2c_client *i2c)
{
        struct wm8978_priv *wm8978;
        int ret;

        wm8978 = devm_kzalloc(&i2c->dev, sizeof(struct wm8978_priv),
                              GFP_KERNEL);
        if (wm8978 == NULL)
                return -ENOMEM;

        wm8978->regmap = devm_regmap_init_i2c(i2c, &wm8978_regmap_config);
        if (IS_ERR(wm8978->regmap)) {
                ret = PTR_ERR(wm8978->regmap);
                dev_err(&i2c->dev, "Failed to allocate regmap: %d\n", ret);
                return ret;
        }

        i2c_set_clientdata(i2c, wm8978);

        /* Reset the codec */
        ret = regmap_write(wm8978->regmap, WM8978_RESET, 0);
        if (ret != 0) {
                dev_err(&i2c->dev, "Failed to issue reset: %d\n", ret);
                return ret;
        }

        ret = devm_snd_soc_register_component(&i2c->dev,
                        &soc_component_dev_wm8978, &wm8978_dai, 1);
        if (ret != 0) {
                dev_err(&i2c->dev, "Failed to register CODEC: %d\n", ret);
                return ret;
        }

        return 0;
}

static const struct i2c_device_id wm8978_i2c_id[] = {
        { "wm8978" },
        { }
};
MODULE_DEVICE_TABLE(i2c, wm8978_i2c_id);

static const struct of_device_id wm8978_of_match[] = {
        { .compatible = "wlf,wm8978", },
        { }
};
MODULE_DEVICE_TABLE(of, wm8978_of_match);

static struct i2c_driver wm8978_i2c_driver = {
        .driver = {
                .name = "wm8978",
                .of_match_table = wm8978_of_match,
        },
        .probe = wm8978_i2c_probe,
        .id_table = wm8978_i2c_id,
};

module_i2c_driver(wm8978_i2c_driver);

MODULE_DESCRIPTION("ASoC WM8978 codec driver");
MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
MODULE_LICENSE("GPL");