Linux音频驱动学习之:(2)移植wm8976声卡驱动(linux-3.4.2)

1.wm8976驱动程序:

/*
 * wm8976.h  --  WM8976 Soc Audio driver
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#ifndef _WM8976_H
#define _WM8976_H

/* WM8976 register space */

#define WM8976_RESET        0x0
#define WM8976_POWER1        0x1
#define WM8976_POWER2        0x2
#define WM8976_POWER3        0x3
#define WM8976_IFACE        0x4
#define WM8976_COMP            0x5
#define WM8976_CLOCK        0x6
#define WM8976_ADD            0x7
#define WM8976_GPIO            0x8
#define WM8976_JACK1        0x9
#define WM8976_DAC            0xa
#define WM8976_DACVOLL        0xb
#define WM8976_DACVOLR      0xc
#define WM8976_JACK2        0xd
#define WM8976_ADC            0xe
#define WM8976_ADCVOL        0xf
#define WM8976_EQ1            0x12
#define WM8976_EQ2            0x13
#define WM8976_EQ3            0x14
#define WM8976_EQ4            0x15
#define WM8976_EQ5            0x16
#define WM8976_DACLIM1        0x18
#define WM8976_DACLIM2        0x19
#define WM8976_NOTCH1        0x1b
#define WM8976_NOTCH2        0x1c
#define WM8976_NOTCH3        0x1d
#define WM8976_NOTCH4        0x1e
#define WM8976_ALC1            0x20
#define WM8976_ALC2            0x21
#define WM8976_ALC3            0x22
#define WM8976_NGATE        0x23
#define WM8976_PLLN            0x24
#define WM8976_PLLK1        0x25
#define WM8976_PLLK2        0x26
#define WM8976_PLLK3        0x27
#define WM8976_3D           0x29
#define WM8976_BEEP         0x2b
#define WM8976_INPUT        0x2c
#define WM8976_INPPGA          0x2d
#define WM8976_ADCBOOST        0x2f
#define WM8976_OUTPUT        0x31
#define WM8976_MIXL            0x32
#define WM8976_MIXR         0x33
#define WM8976_HPVOLL        0x34
#define WM8976_HPVOLR       0x35
#define WM8976_SPKVOLL      0x36
#define WM8976_SPKVOLR      0x37
#define WM8976_OUT3MIX        0x38
#define WM8976_MONOMIX      0x39

#define WM8976_CACHEREGNUM     58

/*
 * WM8976 Clock dividers
 */
#define WM8976_MCLKDIV         0
#define WM8976_BCLKDIV        1
#define WM8976_OPCLKDIV        2
#define WM8976_DACOSR        3
#define WM8976_ADCOSR        4
#define WM8976_MCLKSEL        5

#define WM8976_MCLK_MCLK        (0 << 8)
#define WM8976_MCLK_PLL            (1 << 8)

#define WM8976_MCLK_DIV_1        (0 << 5)
#define WM8976_MCLK_DIV_1_5        (1 << 5)
#define WM8976_MCLK_DIV_2        (2 << 5)
#define WM8976_MCLK_DIV_3        (3 << 5)
#define WM8976_MCLK_DIV_4        (4 << 5)
#define WM8976_MCLK_DIV_5_5        (5 << 5)
#define WM8976_MCLK_DIV_6        (6 << 5)

#define WM8976_BCLK_DIV_1        (0 << 2)
#define WM8976_BCLK_DIV_2        (1 << 2)
#define WM8976_BCLK_DIV_4        (2 << 2)
#define WM8976_BCLK_DIV_8        (3 << 2)
#define WM8976_BCLK_DIV_16        (4 << 2)
#define WM8976_BCLK_DIV_32        (5 << 2)

#define WM8976_DACOSR_64        (0 << 3)
#define WM8976_DACOSR_128        (1 << 3)

#define WM8976_ADCOSR_64        (0 << 3)
#define WM8976_ADCOSR_128        (1 << 3)

#define WM8976_OPCLK_DIV_1        (0 << 4)
#define WM8976_OPCLK_DIV_2        (1 << 4)
#define WM8976_OPCLK_DIV_3        (2 << 4)
#define WM8976_OPCLK_DIV_4        (3 << 4)


#endif
/*
 * wm8976.c  --  WM8976 ALSA Soc Audio driver
 *
 * Copyright 2007-9 Wolfson Microelectronics PLC.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/i2c.h>
#include <linux/spi/spi.h>
#include <linux/platform_device.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/soc-dapm.h>
#include <sound/initval.h>
#include <asm/io.h>

#include "wm8976.h"

static volatile unsigned int *gpbdat;
static volatile unsigned int *gpbcon;


/*
 * wm8976 register cache
 * We can't read the WM8976 register space when we are
 * using 2 wire for device control, so we cache them instead.
 */
static const u16 wm8976_reg[WM8976_CACHEREGNUM] = {
    0x0000, 0x0000, 0x0000, 0x0000,
    0x0050, 0x0000, 0x0140, 0x0000,
    0x0000, 0x0000, 0x0000, 0x00ff,
    0x00ff, 0x0000, 0x0100, 0x00ff,
    0x00ff, 0x0000, 0x012c, 0x002c,
    0x002c, 0x002c, 0x002c, 0x0000,
    0x0032, 0x0000, 0x0000, 0x0000,
    0x0000, 0x0000, 0x0000, 0x0000,
    0x0038, 0x000b, 0x0032, 0x0000,
    0x0008, 0x000c, 0x0093, 0x00e9,
    0x0000, 0x0000, 0x0000, 0x0000,
    0x0033, 0x0010, 0x0010, 0x0100,
    0x0100, 0x0002, 0x0001, 0x0001,
    0x0039, 0x0039, 0x0039, 0x0039,
    0x0001, 0x0001,
};

struct wm8976_priv {
    struct snd_soc_codec codec;
    u16 reg_cache[WM8976_CACHEREGNUM];
};

/*
 * read wm8976 register cache
 */
static inline unsigned int wm8976_read_reg_cache(struct snd_soc_codec  *codec,
    unsigned int reg)
{
    u16 *cache = codec->reg_cache;
    if (reg == WM8976_RESET)
        return 0;
    if (reg >= WM8976_CACHEREGNUM)
        return -1;
    return cache[reg];
}

/*
 * write wm8976 register cache
 */
static inline void wm8976_write_reg_cache(struct snd_soc_codec  *codec,
    u16 reg, unsigned int value)
{
    u16 *cache = codec->reg_cache;
    if (reg >= WM8976_CACHEREGNUM)
        return;
    cache[reg] = value;
}

static void set_csb(int val)
{
    if (val)
    {
        *gpbdat |= (1<<2);
    }
    else
    {
        *gpbdat &= ~(1<<2);
    }
}

static void set_clk(int val)
{
    if (val)
    {
        *gpbdat |= (1<<4);
    }
    else
    {
        *gpbdat &= ~(1<<4);
    }
}

static void set_dat(int val)
{
    if (val)
    {
        *gpbdat |= (1<<3);
    }
    else
    {
        *gpbdat &= ~(1<<3);
    }
}


/*
 * write to the WM8976 register space
 */
static int wm8976_write(struct snd_soc_codec  *codec, unsigned int reg,
    unsigned int value)
{
    int i;
    unsigned short val = (reg << 9) | (value & 0x1ff);

    /* save */
    wm8976_write_reg_cache (codec, reg, value);

    if ((reg == WM8976_HPVOLL) || (reg == WM8976_HPVOLR))
        val |= (1<<8);

    /* write to register */
    set_csb(1);
    set_dat(1);
    set_clk(1);

    for (i = 0; i < 16; i++){
        if (val & (1<<15))
        {
            set_clk(0);
            set_dat(1);
            udelay(1);
            set_clk(1);
        }
        else
        {
            set_clk(0);
            set_dat(0);
            udelay(1);
            set_clk(1);
        }

        val = val << 1;
    }

    set_csb(0);
    udelay(1);
    set_csb(1);
    set_dat(1);
    set_clk(1);
    
    return 0;    
}

#define wm8976_reset(c)    wm8976_write(c, WM8976_RESET, 0)

static const char *wm8976_companding[] = {"Off", "NC", "u-law", "A-law" };
static const char *wm8976_deemp[] = {"None", "32kHz", "44.1kHz", "48kHz" };
static const char *wm8976_eqmode[] = {"Capture", "Playback" };
static const char *wm8976_bw[] = {"Narrow", "Wide" };
static const char *wm8976_eq1[] = {"80Hz", "105Hz", "135Hz", "175Hz" };
static const char *wm8976_eq2[] = {"230Hz", "300Hz", "385Hz", "500Hz" };
static const char *wm8976_eq3[] = {"650Hz", "850Hz", "1.1kHz", "1.4kHz" };
static const char *wm8976_eq4[] = {"1.8kHz", "2.4kHz", "3.2kHz", "4.1kHz" };
static const char *wm8976_eq5[] = {"5.3kHz", "6.9kHz", "9kHz", "11.7kHz" };
static const char *wm8976_alc[] =
    {"ALC both on", "ALC left only", "ALC right only", "Limiter" };

static const struct soc_enum wm8976_enum[] = {
    SOC_ENUM_SINGLE(WM8976_COMP, 1, 4, wm8976_companding), /* adc */
    SOC_ENUM_SINGLE(WM8976_COMP, 3, 4, wm8976_companding), /* dac */
    SOC_ENUM_SINGLE(WM8976_DAC,  4, 4, wm8976_deemp),
    SOC_ENUM_SINGLE(WM8976_EQ1,  8, 2, wm8976_eqmode),

    SOC_ENUM_SINGLE(WM8976_EQ1,  5, 4, wm8976_eq1),
    SOC_ENUM_SINGLE(WM8976_EQ2,  8, 2, wm8976_bw),
    SOC_ENUM_SINGLE(WM8976_EQ2,  5, 4, wm8976_eq2),
    SOC_ENUM_SINGLE(WM8976_EQ3,  8, 2, wm8976_bw),

    SOC_ENUM_SINGLE(WM8976_EQ3,  5, 4, wm8976_eq3),
    SOC_ENUM_SINGLE(WM8976_EQ4,  8, 2, wm8976_bw),
    SOC_ENUM_SINGLE(WM8976_EQ4,  5, 4, wm8976_eq4),
    SOC_ENUM_SINGLE(WM8976_EQ5,  8, 2, wm8976_bw),

    SOC_ENUM_SINGLE(WM8976_EQ5,  5, 4, wm8976_eq5),
    SOC_ENUM_SINGLE(WM8976_ALC3,  8, 2, wm8976_alc),
};

static const struct snd_kcontrol_new wm8976_snd_controls[] = {
SOC_SINGLE("Digital Loopback Switch", WM8976_COMP, 0, 1, 0),

SOC_ENUM("ADC Companding", wm8976_enum[0]),
SOC_ENUM("DAC Companding", wm8976_enum[1]),

SOC_SINGLE("Jack Detection Enable", WM8976_JACK1, 6, 1, 0),

SOC_DOUBLE("DAC Inversion Switch", WM8976_DAC, 0, 1, 1, 0),

//SOC_DOUBLE_R("Headphone Playback Volume", WM8976_DACVOLL, WM8976_DACVOLR, 0, 127, 0),

SOC_SINGLE("High Pass Filter Switch", WM8976_ADC, 8, 1, 0),
//SOC_SINGLE("High Pass Filter Switch", WM8976_ADC, 8, 1, 0),
SOC_SINGLE("High Pass Cut Off", WM8976_ADC, 4, 7, 0),

SOC_DOUBLE("ADC Inversion Switch", WM8976_ADC, 0, 1, 1, 0),

SOC_SINGLE("Capture Volume", WM8976_ADCVOL,  0, 127, 0),

SOC_ENUM("Equaliser Function", wm8976_enum[3]),
SOC_ENUM("EQ1 Cut Off", wm8976_enum[4]),
SOC_SINGLE("EQ1 Volume", WM8976_EQ1,  0, 31, 1),

SOC_ENUM("Equaliser EQ2 Bandwith", wm8976_enum[5]),
SOC_ENUM("EQ2 Cut Off", wm8976_enum[6]),
SOC_SINGLE("EQ2 Volume", WM8976_EQ2,  0, 31, 1),

SOC_ENUM("Equaliser EQ3 Bandwith", wm8976_enum[7]),
SOC_ENUM("EQ3 Cut Off", wm8976_enum[8]),
SOC_SINGLE("EQ3 Volume", WM8976_EQ3,  0, 31, 1),

SOC_ENUM("Equaliser EQ4 Bandwith", wm8976_enum[9]),
SOC_ENUM("EQ4 Cut Off", wm8976_enum[10]),
SOC_SINGLE("EQ4 Volume", WM8976_EQ4,  0, 31, 1),

SOC_ENUM("Equaliser EQ5 Bandwith", wm8976_enum[11]),
SOC_ENUM("EQ5 Cut Off", wm8976_enum[12]),
SOC_SINGLE("EQ5 Volume", WM8976_EQ5,  0, 31, 1),

SOC_SINGLE("DAC Playback Limiter Switch", WM8976_DACLIM1,  8, 1, 0),
SOC_SINGLE("DAC Playback Limiter Decay", WM8976_DACLIM1,  4, 15, 0),
SOC_SINGLE("DAC Playback Limiter Attack", WM8976_DACLIM1,  0, 15, 0),

SOC_SINGLE("DAC Playback Limiter Threshold", WM8976_DACLIM2,  4, 7, 0),
SOC_SINGLE("DAC Playback Limiter Boost", WM8976_DACLIM2,  0, 15, 0),

SOC_SINGLE("ALC Enable Switch", WM8976_ALC1,  8, 1, 0),
SOC_SINGLE("ALC Capture Max Gain", WM8976_ALC1,  3, 7, 0),
SOC_SINGLE("ALC Capture Min Gain", WM8976_ALC1,  0, 7, 0),

SOC_SINGLE("ALC Capture ZC Switch", WM8976_ALC2,  8, 1, 0),
SOC_SINGLE("ALC Capture Hold", WM8976_ALC2,  4, 7, 0),
SOC_SINGLE("ALC Capture Target", WM8976_ALC2,  0, 15, 0),

SOC_ENUM("ALC Capture Mode", wm8976_enum[13]),
SOC_SINGLE("ALC Capture Decay", WM8976_ALC3,  4, 15, 0),
SOC_SINGLE("ALC Capture Attack", WM8976_ALC3,  0, 15, 0),

SOC_SINGLE("ALC Capture Noise Gate Switch", WM8976_NGATE,  3, 1, 0),
SOC_SINGLE("ALC Capture Noise Gate Threshold", WM8976_NGATE,  0, 7, 0),

SOC_SINGLE("Capture PGA ZC Switch", WM8976_INPPGA,  7, 1, 0),
SOC_SINGLE("Capture PGA Volume", WM8976_INPPGA,  0, 63, 0),

SOC_DOUBLE_R("Headphone Playback ZC Switch", WM8976_HPVOLL,  WM8976_HPVOLR, 7, 1, 0),
SOC_DOUBLE_R("Headphone Playback Switch", WM8976_HPVOLL,  WM8976_HPVOLR, 6, 1, 1),
SOC_DOUBLE_R("Headphone Playback Volume", WM8976_HPVOLL,  WM8976_HPVOLR, 0, 63, 0),

SOC_DOUBLE_R("Speaker Playback ZC Switch", WM8976_SPKVOLL,  WM8976_SPKVOLR, 7, 1, 0),
SOC_DOUBLE_R("Speaker Playback Switch", WM8976_SPKVOLL,  WM8976_SPKVOLR, 6, 1, 1),
SOC_DOUBLE_R("Speaker Playback Volume", WM8976_SPKVOLL,  WM8976_SPKVOLR, 0, 63, 0),

SOC_SINGLE("Capture Boost(+20dB)", WM8976_ADCBOOST, 8, 1, 0),
};

/* Left Output Mixer */
static const struct snd_kcontrol_new wm8976_left_mixer_controls[] = {
SOC_DAPM_SINGLE("Right PCM Playback Switch", WM8976_OUTPUT, 6, 1, 1),
SOC_DAPM_SINGLE("Left PCM Playback Switch", WM8976_MIXL, 0, 1, 1),
SOC_DAPM_SINGLE("Line Bypass Switch", WM8976_MIXL, 1, 1, 0),
SOC_DAPM_SINGLE("Aux Playback Switch", WM8976_MIXL, 5, 1, 0),
};

/* Right Output Mixer */
static const struct snd_kcontrol_new wm8976_right_mixer_controls[] = {
SOC_DAPM_SINGLE("Left PCM Playback Switch", WM8976_OUTPUT, 5, 1, 1),
SOC_DAPM_SINGLE("Right PCM Playback Switch", WM8976_MIXR, 0, 1, 1),
SOC_DAPM_SINGLE("Line Bypass Switch", WM8976_MIXR, 1, 1, 0),
SOC_DAPM_SINGLE("Aux Playback Switch", WM8976_MIXR, 5, 1, 0),
};

/* Left AUX Input boost vol */
static const struct snd_kcontrol_new wm8976_laux_boost_controls =
SOC_DAPM_SINGLE("Aux Volume", WM8976_ADCBOOST, 0, 3, 0);

/* Left Input boost vol */
static const struct snd_kcontrol_new wm8976_lmic_boost_controls =
SOC_DAPM_SINGLE("Input Volume", WM8976_ADCBOOST, 4, 3, 0);

/* Left Aux In to PGA */
static const struct snd_kcontrol_new wm8976_laux_capture_boost_controls =
SOC_DAPM_SINGLE("Capture Switch", WM8976_ADCBOOST,  8, 1, 0);

/* Left Input P In to PGA */
static const struct snd_kcontrol_new wm8976_lmicp_capture_boost_controls =
SOC_DAPM_SINGLE("Input P Capture Boost Switch", WM8976_INPUT,  0, 1, 0);

/* Left Input N In to PGA */
static const struct snd_kcontrol_new wm8976_lmicn_capture_boost_controls =
SOC_DAPM_SINGLE("Input N Capture Boost Switch", WM8976_INPUT,  1, 1, 0);

// TODO Widgets
static const struct snd_soc_dapm_widget wm8976_dapm_widgets[] = {
#if 0
//SND_SOC_DAPM_MUTE("Mono Mute", WM8976_MONOMIX, 6, 0),
//SND_SOC_DAPM_MUTE("Speaker Mute", WM8976_SPKMIX, 6, 0),

SND_SOC_DAPM_MIXER("Speaker Mixer", WM8976_POWER3, 2, 0,
    &wm8976_speaker_mixer_controls[0],
    ARRAY_SIZE(wm8976_speaker_mixer_controls)),
SND_SOC_DAPM_MIXER("Mono Mixer", WM8976_POWER3, 3, 0,
    &wm8976_mono_mixer_controls[0],
    ARRAY_SIZE(wm8976_mono_mixer_controls)),
SND_SOC_DAPM_DAC("DAC", "HiFi Playback", WM8976_POWER3, 0, 0),
SND_SOC_DAPM_ADC("ADC", "HiFi Capture", WM8976_POWER3, 0, 0),
SND_SOC_DAPM_PGA("Aux Input", WM8976_POWER1, 6, 0, NULL, 0),
SND_SOC_DAPM_PGA("SpkN Out", WM8976_POWER3, 5, 0, NULL, 0),
SND_SOC_DAPM_PGA("SpkP Out", WM8976_POWER3, 6, 0, NULL, 0),
SND_SOC_DAPM_PGA("Mono Out", WM8976_POWER3, 7, 0, NULL, 0),
SND_SOC_DAPM_PGA("Mic PGA", WM8976_POWER2, 2, 0, NULL, 0),

SND_SOC_DAPM_PGA("Aux Boost", SND_SOC_NOPM, 0, 0,
    &wm8976_aux_boost_controls, 1),
SND_SOC_DAPM_PGA("Mic Boost", SND_SOC_NOPM, 0, 0,
    &wm8976_mic_boost_controls, 1),
SND_SOC_DAPM_SWITCH("Capture Boost", SND_SOC_NOPM, 0, 0,
    &wm8976_capture_boost_controls),

SND_SOC_DAPM_MIXER("Boost Mixer", WM8976_POWER2, 4, 0, NULL, 0),

SND_SOC_DAPM_MICBIAS("Mic Bias", WM8976_POWER1, 4, 0),

SND_SOC_DAPM_INPUT("MICN"),
SND_SOC_DAPM_INPUT("MICP"),
SND_SOC_DAPM_INPUT("AUX"),
SND_SOC_DAPM_OUTPUT("MONOOUT"),
SND_SOC_DAPM_OUTPUT("SPKOUTP"),
SND_SOC_DAPM_OUTPUT("SPKOUTN"),
#endif
};

static const struct snd_soc_dapm_route audio_map[] = {
    /* Mono output mixer */
    {"Mono Mixer", "PCM Playback Switch", "DAC"},
    {"Mono Mixer", "Aux Playback Switch", "Aux Input"},
    {"Mono Mixer", "Line Bypass Switch", "Boost Mixer"},

    /* Speaker output mixer */
    {"Speaker Mixer", "PCM Playback Switch", "DAC"},
    {"Speaker Mixer", "Aux Playback Switch", "Aux Input"},
    {"Speaker Mixer", "Line Bypass Switch", "Boost Mixer"},

    /* Outputs */
    {"Mono Out", NULL, "Mono Mixer"},
    {"MONOOUT", NULL, "Mono Out"},
    {"SpkN Out", NULL, "Speaker Mixer"},
    {"SpkP Out", NULL, "Speaker Mixer"},
    {"SPKOUTN", NULL, "SpkN Out"},
    {"SPKOUTP", NULL, "SpkP Out"},

    /* Boost Mixer */
    {"Boost Mixer", NULL, "ADC"},
    {"Capture Boost Switch", "Aux Capture Boost Switch", "AUX"},
    {"Aux Boost", "Aux Volume", "Boost Mixer"},
    {"Capture Boost", "Capture Switch", "Boost Mixer"},
    {"Mic Boost", "Mic Volume", "Boost Mixer"},

    /* Inputs */
    {"MICP", NULL, "Mic Boost"},
    {"MICN", NULL, "Mic PGA"},
    {"Mic PGA", NULL, "Capture Boost"},
    {"AUX", NULL, "Aux Input"},
};

static int wm8976_add_widgets(struct snd_soc_codec *codec)
{
    struct snd_soc_dapm_context *dapm = &codec->dapm;
    snd_soc_dapm_new_controls(dapm, wm8976_dapm_widgets,
                  ARRAY_SIZE(wm8976_dapm_widgets));

    snd_soc_dapm_add_routes(dapm, audio_map, ARRAY_SIZE(audio_map));

    snd_soc_dapm_new_widgets(dapm);
    return 0;
}

struct _pll_div {
    unsigned int pre:4; /* prescale - 1 */
    unsigned int n:4;
    unsigned int k;
};

static struct _pll_div pll_div;

/* The size in bits of the pll divide multiplied by 10
 * to allow rounding later */
#define FIXED_PLL_SIZE ((1 << 24) * 10)

static void pll_factors(unsigned int target, unsigned int source)
{
    unsigned long long Kpart;
    unsigned int K, Ndiv, Nmod;

    Ndiv = target / source;
    if (Ndiv < 6) {
        source >>= 1;
        pll_div.pre = 1;
        Ndiv = target / source;
    } else
        pll_div.pre = 0;

    if ((Ndiv < 6) || (Ndiv > 12))
        printk(KERN_WARNING
            "WM8976 N value outwith recommended range! N = %d
",Ndiv);

    pll_div.n = Ndiv;
    Nmod = target % source;
    Kpart = FIXED_PLL_SIZE * (long long)Nmod;

    do_div(Kpart, source);

    K = Kpart & 0xFFFFFFFF;

    /* Check if we need to round */
    if ((K % 10) >= 5)
        K += 5;

    /* Move down to proper range now rounding is done */
    K /= 10;

    pll_div.k = K;
}

static int wm8976_set_dai_pll(struct snd_soc_dai *codec_dai,
        int pll_id, int source, unsigned int freq_in, unsigned int freq_out)
{
    struct snd_soc_codec *codec = codec_dai->codec;
    u16 reg;

    if(freq_in == 0 || freq_out == 0) {
        reg = wm8976_read_reg_cache(codec, WM8976_POWER1);
        wm8976_write(codec, WM8976_POWER1, reg & 0x1df);
        return 0;
    }

    pll_factors(freq_out * 8, freq_in);

    wm8976_write(codec, WM8976_PLLN, (pll_div.pre << 4) | pll_div.n);
    wm8976_write(codec, WM8976_PLLK1, pll_div.k >> 18);
    wm8976_write(codec, WM8976_PLLK1, (pll_div.k >> 9) && 0x1ff);
    wm8976_write(codec, WM8976_PLLK1, pll_div.k && 0x1ff);
    reg = wm8976_read_reg_cache(codec, WM8976_POWER1);
    wm8976_write(codec, WM8976_POWER1, reg | 0x020);
    
    
    return 0;
}

static int wm8976_set_dai_fmt(struct snd_soc_dai *codec_dai,
        unsigned int fmt)
{
    struct snd_soc_codec *codec = codec_dai->codec;
    u16 iface = wm8976_read_reg_cache(codec, WM8976_IFACE) & 0x3;
    u16 clk = wm8976_read_reg_cache(codec, WM8976_CLOCK) & 0xfffe;

    /* set master/slave audio interface */
    switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
    case SND_SOC_DAIFMT_CBM_CFM:
        clk |= 0x0001;
        break;
    case SND_SOC_DAIFMT_CBS_CFS:
        break;
    default:
        return -EINVAL;
    }

    /* interface format */
    switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
    case SND_SOC_DAIFMT_I2S:
        iface |= 0x0010;
        break;
    case SND_SOC_DAIFMT_RIGHT_J:
        break;
    case SND_SOC_DAIFMT_LEFT_J:
        iface |= 0x0008;
        break;
    case SND_SOC_DAIFMT_DSP_A:
        iface |= 0x00018;
        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 |= 0x0180;
        break;
    case SND_SOC_DAIFMT_IB_NF:
        iface |= 0x0100;
        break;
    case SND_SOC_DAIFMT_NB_IF:
        iface |= 0x0080;
        break;
    default:
        return -EINVAL;
    }

    wm8976_write(codec, WM8976_IFACE, iface);
    wm8976_write(codec, WM8976_CLOCK, clk);

    return 0;
}

static int wm8976_hw_params(struct snd_pcm_substream *substream,
                struct snd_pcm_hw_params *params,
                struct snd_soc_dai *dai)
{
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct snd_soc_codec *codec = rtd->codec;
    u16 iface = wm8976_read_reg_cache(codec, WM8976_IFACE) & 0xff9f;
    u16 adn = wm8976_read_reg_cache(codec, WM8976_ADD) & 0x1f1;

    /* bit size */
    switch (params_format(params)) {
    case SNDRV_PCM_FORMAT_S16_LE:
        break;
    case SNDRV_PCM_FORMAT_S20_3LE:
        iface |= 0x0020;
        break;
    case SNDRV_PCM_FORMAT_S24_LE:
        iface |= 0x0040;
        break;
    }

    /* filter coefficient */
    switch (params_rate(params)) {
    case SNDRV_PCM_RATE_8000:
        adn |= 0x5 << 1;
        break;
    case SNDRV_PCM_RATE_11025:
        adn |= 0x4 << 1;
        break;
    case SNDRV_PCM_RATE_16000:
        adn |= 0x3 << 1;
        break;
    case SNDRV_PCM_RATE_22050:
        adn |= 0x2 << 1;
        break;
    case SNDRV_PCM_RATE_32000:
        adn |= 0x1 << 1;
        break;
    }

    /* set iface */
    wm8976_write(codec, WM8976_IFACE, iface);
    wm8976_write(codec, WM8976_ADD, adn);
    return 0;
}

static int wm8976_set_dai_clkdiv(struct snd_soc_dai *codec_dai,
        int div_id, int div)
{
    struct snd_soc_codec *codec = codec_dai->codec;
    u16 reg;

    switch (div_id) {
    case WM8976_MCLKDIV:
        reg = wm8976_read_reg_cache(codec, WM8976_CLOCK) & 0x11f;
        wm8976_write(codec, WM8976_CLOCK, reg | div);
        break;
    case WM8976_BCLKDIV:
        reg = wm8976_read_reg_cache(codec, WM8976_CLOCK) & 0x1c7;
        wm8976_write(codec, WM8976_CLOCK, reg | div);
        break;
    case WM8976_OPCLKDIV:
        reg = wm8976_read_reg_cache(codec, WM8976_GPIO) & 0x1cf;
        wm8976_write(codec, WM8976_GPIO, reg | div);
        break;
    case WM8976_DACOSR:
        reg = wm8976_read_reg_cache(codec, WM8976_DAC) & 0x1f7;
        wm8976_write(codec, WM8976_DAC, reg | div);
        break;
    case WM8976_ADCOSR:
        reg = wm8976_read_reg_cache(codec, WM8976_ADC) & 0x1f7;
        wm8976_write(codec, WM8976_ADC, reg | div);
        break;
    case WM8976_MCLKSEL:
        reg = wm8976_read_reg_cache(codec, WM8976_CLOCK) & 0x0ff;
        wm8976_write(codec, WM8976_CLOCK, reg | div);
        break;
    default:
        return -EINVAL;
    }

    return 0;
}

static int wm8976_mute(struct snd_soc_dai *dai, int mute)
{
    struct snd_soc_codec *codec = dai->codec;
    u16 mute_reg = wm8976_read_reg_cache(codec, WM8976_DAC) & 0xffbf;

    if(mute)
        wm8976_write(codec, WM8976_DAC, mute_reg | 0x40);
    else {
        wm8976_write(codec, WM8976_DAC, mute_reg);
    }

    return 0;
}

/* TODO: liam need to make this lower power with dapm */
static int wm8976_set_bias_level(struct snd_soc_codec *codec,
    enum snd_soc_bias_level level)
{

    switch (level) {
    case SND_SOC_BIAS_ON:
        wm8976_write(codec, WM8976_POWER1, 0x1ff);
        wm8976_write(codec, WM8976_POWER2, 0x1ff & ~(1<<6));
        wm8976_write(codec, WM8976_POWER3, 0x1ff);
        break;
    case SND_SOC_BIAS_STANDBY:
    case SND_SOC_BIAS_PREPARE:
        break;
    case SND_SOC_BIAS_OFF:
        wm8976_write(codec, WM8976_POWER1, 0x0);
        wm8976_write(codec, WM8976_POWER2, 0x0);
        wm8976_write(codec, WM8976_POWER3, 0x0);
        break;
    }
    codec->dapm.bias_level = level;
    return 0;
}

#define WM8976_RATES 
    (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 | SNDRV_PCM_RATE_16000 | 
    SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | 
    SNDRV_PCM_RATE_48000)

#define WM8976_FORMATS 
    (SNDRV_PCM_FORMAT_S16_LE | SNDRV_PCM_FORMAT_S20_3LE | 
    SNDRV_PCM_FORMAT_S24_3LE | SNDRV_PCM_FORMAT_S24_LE)

static struct snd_soc_dai_ops wm8976_dai_ops = {
    .hw_params = wm8976_hw_params,
    .digital_mute = wm8976_mute,
    .set_fmt = wm8976_set_dai_fmt,
    .set_clkdiv = wm8976_set_dai_clkdiv,
    .set_pll = wm8976_set_dai_pll,
};

struct snd_soc_dai_driver wm8976_dai = {
    .name = "wm8976-iis",
    .playback = {
        .stream_name = "Playback",
        .channels_min = 1,
        .channels_max = 2,
        .rates = WM8976_RATES,
        .formats = WM8976_FORMATS,},
    .capture = {
        .stream_name = "Capture",
        .channels_min = 1,
        .channels_max = 1,
        .rates = WM8976_RATES,
        .formats = WM8976_FORMATS,},
    .ops = &wm8976_dai_ops,
};

static int snd_soc_wm8976_suspend(struct snd_soc_codec *codec)
{
    wm8976_set_bias_level(codec, SND_SOC_BIAS_OFF);
    return 0;
}

static int snd_soc_wm8976_resume(struct snd_soc_codec *codec)
{
    int i;
    u16 *cache = codec->reg_cache;

    /* Sync reg_cache with the hardware */
    for (i = 0; i < ARRAY_SIZE(wm8976_reg); i++) {
        codec->write(codec->control_data, i, cache[i]);
    }
    wm8976_set_bias_level(codec, SND_SOC_BIAS_PREPARE);
    wm8976_set_bias_level(codec, SND_SOC_BIAS_ON);
    return 0;
}

static int snd_soc_wm8976_probe(struct snd_soc_codec *codec)
{
    gpbcon = ioremap(0x56000010, 4);
    gpbdat = ioremap(0x56000014, 4);
    
    /* GPB 4: L3CLOCK */
    /* GPB 3: L3DATA */
    /* GPB 2: L3MODE */
    *gpbcon &= ~((3<<4) | (3<<6) | (3<<8));
    *gpbcon |= ((1<<4) | (1<<6) | (1<<8));



    snd_soc_add_codec_controls(codec, wm8976_snd_controls,
                 ARRAY_SIZE(wm8976_snd_controls));
    //wm8976_add_widgets(codec);

    return 0;

}

/* power down chip */
static int snd_soc_wm8976_remove(struct snd_soc_codec *codec)
{
    struct snd_soc_dapm_context *dapm = &codec->dapm;

    //snd_soc_dapm_free(dapm);

    iounmap(gpbcon);
    iounmap(gpbdat);

    return 0;
}


struct snd_soc_codec_driver soc_codec_dev_wm8976 = {
    .probe =     snd_soc_wm8976_probe,
    .remove =     snd_soc_wm8976_remove,
    .suspend =     snd_soc_wm8976_suspend,
    .resume =    snd_soc_wm8976_resume,
    .reg_cache_size = sizeof(wm8976_reg),
    .reg_word_size = sizeof(u16),
    .reg_cache_default = wm8976_reg,
    .reg_cache_step = 2,
    .read = wm8976_read_reg_cache,
    .write = wm8976_write,
    .set_bias_level = wm8976_set_bias_level,
};

/* ͨ¹ý×¢²áƽ̨É豸¡¢Æ½Ì¨Çý¶¯À´ÊµÏÖ¶Ôsnd_soc_register_codecµÄµ÷ÓÃ
 *
 */

static void wm8976_dev_release(struct device * dev)
{
}

static int wm8976_probe(struct platform_device *pdev)
{
    return snd_soc_register_codec(&pdev->dev,
            &soc_codec_dev_wm8976, &wm8976_dai, 1);
}

static int wm8976_remove(struct platform_device *pdev)
{
    snd_soc_unregister_codec(&pdev->dev);
    return 0;
}

static struct platform_device wm8976_dev = {
    .name         = "wm8976-codec",
    .id       = -1,
    .dev = { 
        .release = wm8976_dev_release, 
    },
};
struct platform_driver wm8976_drv = {
    .probe        = wm8976_probe,
    .remove        = wm8976_remove,
    .driver        = {
        .name    = "wm8976-codec",
    }
};

static int wm8976_init(void)
{    
    platform_device_register(&wm8976_dev);
    platform_driver_register(&wm8976_drv);
    return 0;
}

static void wm8976_exit(void)
{
    platform_device_unregister(&wm8976_dev);
    platform_driver_unregister(&wm8976_drv);
}

module_init(wm8976_init);
module_exit(wm8976_exit);

MODULE_LICENSE("GPL");
#include <stdio.h>
#include <stdlib.h>
#include <alsa/asoundlib.h>

snd_pcm_t *open_sound_dev(snd_pcm_stream_t type)
{
    int err;
    snd_pcm_t *handle;
    snd_pcm_hw_params_t *hw_params;
    unsigned int rate = 44100;

    if ((err = snd_pcm_open (&handle, "default", type, 0)) < 0) {
        return NULL;
    }
       
    if ((err = snd_pcm_hw_params_malloc (&hw_params)) < 0) {
        fprintf (stderr, "cannot allocate hardware parameter structure (%s)
",
             snd_strerror (err));
        return NULL;
    }
             
    if ((err = snd_pcm_hw_params_any (handle, hw_params)) < 0) {
        fprintf (stderr, "cannot initialize hardware parameter structure (%s)
",
             snd_strerror (err));
        return NULL;
    }

    if ((err = snd_pcm_hw_params_set_access (handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
        fprintf (stderr, "cannot set access type (%s)
",
             snd_strerror (err));
        return NULL;
    }

    if ((err = snd_pcm_hw_params_set_format (handle, hw_params, SND_PCM_FORMAT_S16_LE)) < 0) {
        fprintf (stderr, "cannot set sample format (%s)
",
             snd_strerror (err));
        return NULL;
    }

    if ((err = snd_pcm_hw_params_set_rate_near (handle, hw_params, &rate, 0)) < 0) {
        fprintf (stderr, "cannot set sample rate (%s)
",
             snd_strerror (err));
        return NULL;
    }

    if ((err = snd_pcm_hw_params_set_channels (handle, hw_params, 2)) < 0) {
        fprintf (stderr, "cannot set channel count (%s)
",
             snd_strerror (err));
        return NULL;
    }

    if ((err = snd_pcm_hw_params (handle, hw_params)) < 0) {
        fprintf (stderr, "cannot set parameters (%s)
",
             snd_strerror (err));
        return NULL;
    }

    snd_pcm_hw_params_free (hw_params);

    return handle;
}

void close_sound_dev(snd_pcm_t *handle)
{
    snd_pcm_close (handle);
}

snd_pcm_t *open_playback(void)
{
    return open_sound_dev(SND_PCM_STREAM_PLAYBACK);
}

snd_pcm_t *open_capture(void)
{
    return open_sound_dev(SND_PCM_STREAM_CAPTURE);
}


int main (int argc, char *argv[])
{
    int err;
    char buf[512];
    snd_pcm_t *playback_handle;
    snd_pcm_t *capture_handle;


    playback_handle = open_playback();
    if (!playback_handle)
    {
        fprintf (stderr, "cannot open for playback
");
        return -1;
    }


    capture_handle = open_capture();
    if (!capture_handle)
    {
        fprintf (stderr, "cannot open for capture
");
        return -1;
    }

    if ((err = snd_pcm_prepare (playback_handle)) < 0) {
        fprintf (stderr, "cannot prepare audio interface for use (%s)
",
             snd_strerror (err));
        return -1;
    }

    if ((err = snd_pcm_prepare (capture_handle)) < 0) {
        fprintf (stderr, "cannot prepare audio interface for use (%s)
",
             snd_strerror (err));
        return -1;
    }

    while (1) {
        if ((err = snd_pcm_readi (capture_handle, buf, 128)) != 128) {
            fprintf (stderr, "read from audio interface failed (%s)
",
                 snd_strerror (err));
            return -1;
        }

        if ((err = snd_pcm_writei (playback_handle, buf, 128)) != 128) {
            fprintf (stderr, "write to audio interface failed (%s)
",
                 snd_strerror (err));
            return -1;
        }
    }

    snd_pcm_close (playback_handle);
    snd_pcm_close (capture_handle);
    return 0;
}

Makefile

capture_playback : capture_playback.c
    arm-linux-gcc -Wall -o capture_playback capture_playback.c -lasound

clean:
    rm capture_playback

 

原文地址:https://www.cnblogs.com/blogs-of-lxl/p/6539022.html