// SPDX-License-Identifier: GPL-2.0-or-later
/* Atmel PDMIC driver
 *
 * Copyright (C) 2015 Atmel
 *
 * Author: Songjun Wu <songjun.wu@atmel.com>
 */

#include <linux/of.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <sound/core.h>
#include <sound/dmaengine_pcm.h>
#include <sound/pcm_params.h>
#include <sound/tlv.h>
#include "atmel-pdmic.h"

struct atmel_pdmic_pdata {
        u32 mic_min_freq;
        u32 mic_max_freq;
        s32 mic_offset;
        const char *card_name;
};

struct atmel_pdmic {
        dma_addr_t phy_base;
        struct regmap *regmap;
        struct clk *pclk;
        struct clk *gclk;
        struct device *dev;
        int irq;
        struct snd_pcm_substream *substream;
        const struct atmel_pdmic_pdata *pdata;
};

static const struct of_device_id atmel_pdmic_of_match[] = {
        {
                .compatible = "atmel,sama5d2-pdmic",
        }, {
                /* sentinel */
        }
};
MODULE_DEVICE_TABLE(of, atmel_pdmic_of_match);

#define PDMIC_OFFSET_MAX_VAL    S16_MAX
#define PDMIC_OFFSET_MIN_VAL    S16_MIN

static struct atmel_pdmic_pdata *atmel_pdmic_dt_init(struct device *dev)
{
        struct device_node *np = dev->of_node;
        struct atmel_pdmic_pdata *pdata;

        if (!np) {
                dev_err(dev, "device node not found\n");
                return ERR_PTR(-EINVAL);
        }

        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return ERR_PTR(-ENOMEM);

        if (of_property_read_string(np, "atmel,model", &pdata->card_name))
                pdata->card_name = "PDMIC";

        if (of_property_read_u32(np, "atmel,mic-min-freq",
                                 &pdata->mic_min_freq)) {
                dev_err(dev, "failed to get mic-min-freq\n");
                return ERR_PTR(-EINVAL);
        }

        if (of_property_read_u32(np, "atmel,mic-max-freq",
                                 &pdata->mic_max_freq)) {
                dev_err(dev, "failed to get mic-max-freq\n");
                return ERR_PTR(-EINVAL);
        }

        if (pdata->mic_max_freq < pdata->mic_min_freq) {
                dev_err(dev,
                        "mic-max-freq should not be less than mic-min-freq\n");
                return ERR_PTR(-EINVAL);
        }

        if (of_property_read_s32(np, "atmel,mic-offset", &pdata->mic_offset))
                pdata->mic_offset = 0;

        if (pdata->mic_offset > PDMIC_OFFSET_MAX_VAL) {
                dev_warn(dev,
                         "mic-offset value %d is larger than the max value %d, the max value is specified\n",
                         pdata->mic_offset, PDMIC_OFFSET_MAX_VAL);
                pdata->mic_offset = PDMIC_OFFSET_MAX_VAL;
        } else if (pdata->mic_offset < PDMIC_OFFSET_MIN_VAL) {
                dev_warn(dev,
                         "mic-offset value %d is less than the min value %d, the min value is specified\n",
                         pdata->mic_offset, PDMIC_OFFSET_MIN_VAL);
                pdata->mic_offset = PDMIC_OFFSET_MIN_VAL;
        }

        return pdata;
}

/* cpu dai component */
static int atmel_pdmic_cpu_dai_startup(struct snd_pcm_substream *substream,
                                        struct snd_soc_dai *cpu_dai)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);
        int ret;

        ret = clk_prepare_enable(dd->gclk);
        if (ret)
                return ret;

        ret =  clk_prepare_enable(dd->pclk);
        if (ret) {
                clk_disable_unprepare(dd->gclk);
                return ret;
        }

        /* Clear all bits in the Control Register(PDMIC_CR) */
        regmap_write(dd->regmap, PDMIC_CR, 0);

        dd->substream = substream;

        /* Enable the overrun error interrupt */
        regmap_write(dd->regmap, PDMIC_IER, PDMIC_IER_OVRE);

        return 0;
}

static void atmel_pdmic_cpu_dai_shutdown(struct snd_pcm_substream *substream,
                                        struct snd_soc_dai *cpu_dai)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);

        /* Disable the overrun error interrupt */
        regmap_write(dd->regmap, PDMIC_IDR, PDMIC_IDR_OVRE);

        clk_disable_unprepare(dd->gclk);
        clk_disable_unprepare(dd->pclk);
}

static int atmel_pdmic_cpu_dai_prepare(struct snd_pcm_substream *substream,
                                        struct snd_soc_dai *cpu_dai)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);
        struct snd_soc_component *component = cpu_dai->component;
        u32 val;
        int ret;

        /* Clean the PDMIC Converted Data Register */
        ret = regmap_read(dd->regmap, PDMIC_CDR, &val);
        if (ret < 0)
                return 0;

        ret = snd_soc_component_update_bits(component, PDMIC_CR,
                                            PDMIC_CR_ENPDM_MASK,
                                            PDMIC_CR_ENPDM_DIS <<
                                            PDMIC_CR_ENPDM_SHIFT);
        if (ret < 0)
                return ret;

        return 0;
}

#define ATMEL_PDMIC_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S32_LE)

/* platform */
#define ATMEL_PDMIC_MAX_BUF_SIZE  (64 * 1024)
#define ATMEL_PDMIC_PREALLOC_BUF_SIZE  ATMEL_PDMIC_MAX_BUF_SIZE

static const struct snd_pcm_hardware atmel_pdmic_hw = {
        .info                   = SNDRV_PCM_INFO_MMAP
                                | SNDRV_PCM_INFO_MMAP_VALID
                                | SNDRV_PCM_INFO_INTERLEAVED
                                | SNDRV_PCM_INFO_RESUME
                                | SNDRV_PCM_INFO_PAUSE,
        .formats                = ATMEL_PDMIC_FORMATS,
        .buffer_bytes_max       = ATMEL_PDMIC_MAX_BUF_SIZE,
        .period_bytes_min       = 256,
        .period_bytes_max       = 32 * 1024,
        .periods_min            = 2,
        .periods_max            = 256,
};

static int
atmel_pdmic_platform_configure_dma(struct snd_pcm_substream *substream,
                                struct snd_pcm_hw_params *params,
                                struct dma_slave_config *slave_config)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);
        int ret;

        ret = snd_hwparams_to_dma_slave_config(substream, params,
                                               slave_config);
        if (ret) {
                dev_err(dd->dev,
                        "hw params to dma slave configure failed\n");
                return ret;
        }

        slave_config->src_addr          = dd->phy_base + PDMIC_CDR;
        slave_config->src_maxburst      = 1;
        slave_config->dst_maxburst      = 1;

        return 0;
}

static const struct snd_dmaengine_pcm_config
atmel_pdmic_dmaengine_pcm_config = {
        .prepare_slave_config   = atmel_pdmic_platform_configure_dma,
        .pcm_hardware           = &atmel_pdmic_hw,
        .prealloc_buffer_size   = ATMEL_PDMIC_PREALLOC_BUF_SIZE,
};

/* codec */
/* Mic Gain = dgain * 2^(-scale) */
struct mic_gain {
        unsigned int dgain;
        unsigned int scale;
};

/* range from -90 dB to 90 dB */
static const struct mic_gain mic_gain_table[] = {
{    1, 15}, {    1, 14},                           /* -90, -84 dB */
{    3, 15}, {    1, 13}, {    3, 14}, {    1, 12}, /* -81, -78, -75, -72 dB */
{    5, 14}, {   13, 15},                           /* -70, -68 dB */
{    9, 14}, {   21, 15}, {   23, 15}, {   13, 14}, /* -65 ~ -62 dB */
{   29, 15}, {   33, 15}, {   37, 15}, {   41, 15}, /* -61 ~ -58 dB */
{   23, 14}, {   13, 13}, {   58, 15}, {   65, 15}, /* -57 ~ -54 dB */
{   73, 15}, {   41, 14}, {   23, 13}, {   13, 12}, /* -53 ~ -50 dB */
{   29, 13}, {   65, 14}, {   73, 14}, {   41, 13}, /* -49 ~ -46 dB */
{   23, 12}, {  207, 15}, {   29, 12}, {   65, 13}, /* -45 ~ -42 dB */
{   73, 13}, {   41, 12}, {   23, 11}, {  413, 15}, /* -41 ~ -38 dB */
{  463, 15}, {  519, 15}, {  583, 15}, {  327, 14}, /* -37 ~ -34 dB */
{  367, 14}, {  823, 15}, {  231, 13}, { 1036, 15}, /* -33 ~ -30 dB */
{ 1163, 15}, { 1305, 15}, {  183, 12}, { 1642, 15}, /* -29 ~ -26 dB */
{ 1843, 15}, { 2068, 15}, {  145, 11}, { 2603, 15}, /* -25 ~ -22 dB */
{  365, 12}, { 3277, 15}, { 3677, 15}, { 4125, 15}, /* -21 ~ -18 dB */
{ 4629, 15}, { 5193, 15}, { 5827, 15}, { 3269, 14}, /* -17 ~ -14 dB */
{  917, 12}, { 8231, 15}, { 9235, 15}, { 5181, 14}, /* -13 ~ -10 dB */
{11627, 15}, {13045, 15}, {14637, 15}, {16423, 15}, /*  -9 ~ -6 dB */
{18427, 15}, {20675, 15}, { 5799, 13}, {26029, 15}, /*  -5 ~ -2 dB */
{ 7301, 13}, {    1,  0}, {18383, 14}, {10313, 13}, /*  -1 ~ 2 dB */
{23143, 14}, {25967, 14}, {29135, 14}, {16345, 13}, /*   3 ~ 6 dB */
{ 4585, 11}, {20577, 13}, { 1443,  9}, {25905, 13}, /*   7 ~ 10 dB */
{14533, 12}, { 8153, 11}, { 2287,  9}, {20529, 12}, /*  11 ~ 14 dB */
{11517, 11}, { 6461, 10}, {28997, 12}, { 4067,  9}, /*  15 ~ 18 dB */
{18253, 11}, {   10,  0}, {22979, 11}, {25783, 11}, /*  19 ~ 22 dB */
{28929, 11}, {32459, 11}, { 9105,  9}, {20431, 10}, /*  23 ~ 26 dB */
{22925, 10}, {12861,  9}, { 7215,  8}, {16191,  9}, /*  27 ~ 30 dB */
{ 9083,  8}, {20383,  9}, {11435,  8}, { 6145,  7}, /*  31 ~ 34 dB */
{ 3599,  6}, {32305,  9}, {18123,  8}, {20335,  8}, /*  35 ~ 38 dB */
{  713,  3}, {  100,  0}, { 7181,  6}, { 8057,  6}, /*  39 ~ 42 dB */
{  565,  2}, {20287,  7}, {11381,  6}, {25539,  7}, /*  43 ~ 46 dB */
{ 1791,  3}, { 4019,  4}, { 9019,  5}, {20239,  6}, /*  47 ~ 50 dB */
{ 5677,  4}, {25479,  6}, { 7147,  4}, { 8019,  4}, /*  51 ~ 54 dB */
{17995,  5}, {20191,  5}, {11327,  4}, {12709,  4}, /*  55 ~ 58 dB */
{ 3565,  2}, { 1000,  0}, { 1122,  0}, { 1259,  0}, /*  59 ~ 62 dB */
{ 2825,  1}, {12679,  3}, { 7113,  2}, { 7981,  2}, /*  63 ~ 66 dB */
{ 8955,  2}, {20095,  3}, {22547,  3}, {12649,  2}, /*  67 ~ 70 dB */
{28385,  3}, { 3981,  0}, {17867,  2}, {20047,  2}, /*  71 ~ 74 dB */
{11247,  1}, {12619,  1}, {14159,  1}, {31773,  2}, /*  75 ~ 78 dB */
{17825,  1}, {10000,  0}, {11220,  0}, {12589,  0}, /*  79 ~ 82 dB */
{28251,  1}, {15849,  0}, {17783,  0}, {19953,  0}, /*  83 ~ 86 dB */
{22387,  0}, {25119,  0}, {28184,  0}, {31623,  0}, /*  87 ~ 90 dB */
};

static const DECLARE_TLV_DB_RANGE(mic_gain_tlv,
        0, 1, TLV_DB_SCALE_ITEM(-9000, 600, 0),
        2, 5, TLV_DB_SCALE_ITEM(-8100, 300, 0),
        6, 7, TLV_DB_SCALE_ITEM(-7000, 200, 0),
        8, ARRAY_SIZE(mic_gain_table)-1, TLV_DB_SCALE_ITEM(-6500, 100, 0),
);

static int pdmic_get_mic_volsw(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
        unsigned int dgain_val, scale_val;
        int i;

        dgain_val = (snd_soc_component_read(component, PDMIC_DSPR1) & PDMIC_DSPR1_DGAIN_MASK)
                    >> PDMIC_DSPR1_DGAIN_SHIFT;

        scale_val = (snd_soc_component_read(component, PDMIC_DSPR0) & PDMIC_DSPR0_SCALE_MASK)
                    >> PDMIC_DSPR0_SCALE_SHIFT;

        for (i = 0; i < ARRAY_SIZE(mic_gain_table); i++) {
                if ((mic_gain_table[i].dgain == dgain_val) &&
                    (mic_gain_table[i].scale == scale_val))
                        ucontrol->value.integer.value[0] = i;
        }

        return 0;
}

static int pdmic_put_mic_volsw(struct snd_kcontrol *kcontrol,
        struct snd_ctl_elem_value *ucontrol)
{
        struct soc_mixer_control *mc =
                (struct soc_mixer_control *)kcontrol->private_value;
        struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
        int max = mc->max;
        unsigned int val;
        int ret;

        val = ucontrol->value.integer.value[0];

        if (val > max)
                return -EINVAL;

        ret = snd_soc_component_update_bits(component, PDMIC_DSPR1, PDMIC_DSPR1_DGAIN_MASK,
                         mic_gain_table[val].dgain << PDMIC_DSPR1_DGAIN_SHIFT);
        if (ret < 0)
                return ret;

        ret = snd_soc_component_update_bits(component, PDMIC_DSPR0, PDMIC_DSPR0_SCALE_MASK,
                         mic_gain_table[val].scale << PDMIC_DSPR0_SCALE_SHIFT);
        if (ret < 0)
                return ret;

        return 0;
}

static const struct snd_kcontrol_new atmel_pdmic_snd_controls[] = {
SOC_SINGLE_EXT_TLV("Mic Capture Volume", PDMIC_DSPR1, PDMIC_DSPR1_DGAIN_SHIFT,
                   ARRAY_SIZE(mic_gain_table)-1, 0,
                   pdmic_get_mic_volsw, pdmic_put_mic_volsw, mic_gain_tlv),

SOC_SINGLE("High Pass Filter Switch", PDMIC_DSPR0,
           PDMIC_DSPR0_HPFBYP_SHIFT, 1, 1),

SOC_SINGLE("SINCC Filter Switch", PDMIC_DSPR0, PDMIC_DSPR0_SINBYP_SHIFT, 1, 1),
};

static int atmel_pdmic_component_probe(struct snd_soc_component *component)
{
        struct snd_soc_card *card = snd_soc_component_get_drvdata(component);
        struct atmel_pdmic *dd = snd_soc_card_get_drvdata(card);

        snd_soc_component_update_bits(component, PDMIC_DSPR1, PDMIC_DSPR1_OFFSET_MASK,
                     (u32)(dd->pdata->mic_offset << PDMIC_DSPR1_OFFSET_SHIFT));

        return 0;
}

#define PDMIC_MR_PRESCAL_MAX_VAL 127

static int
atmel_pdmic_cpu_dai_hw_params(struct snd_pcm_substream *substream,
                              struct snd_pcm_hw_params *params,
                              struct snd_soc_dai *cpu_dai)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);
        struct snd_soc_component *component = cpu_dai->component;
        unsigned int rate_min = substream->runtime->hw.rate_min;
        unsigned int rate_max = substream->runtime->hw.rate_max;
        int fs = params_rate(params);
        int bits = params_width(params);
        unsigned long pclk_rate, gclk_rate;
        unsigned int f_pdmic;
        u32 mr_val, dspr0_val, pclk_prescal, gclk_prescal;

        if (params_channels(params) != 1) {
                dev_err(component->dev,
                        "only supports one channel\n");
                return -EINVAL;
        }

        if ((fs < rate_min) || (fs > rate_max)) {
                dev_err(component->dev,
                        "sample rate is %dHz, min rate is %dHz, max rate is %dHz\n",
                        fs, rate_min, rate_max);

                return -EINVAL;
        }

        switch (bits) {
        case 16:
                dspr0_val = (PDMIC_DSPR0_SIZE_16_BITS
                             << PDMIC_DSPR0_SIZE_SHIFT);
                break;
        case 32:
                dspr0_val = (PDMIC_DSPR0_SIZE_32_BITS
                             << PDMIC_DSPR0_SIZE_SHIFT);
                break;
        default:
                return -EINVAL;
        }

        if ((fs << 7) > (rate_max << 6)) {
                f_pdmic = fs << 6;
                dspr0_val |= PDMIC_DSPR0_OSR_64 << PDMIC_DSPR0_OSR_SHIFT;
        } else {
                f_pdmic = fs << 7;
                dspr0_val |= PDMIC_DSPR0_OSR_128 << PDMIC_DSPR0_OSR_SHIFT;
        }

        pclk_rate = clk_get_rate(dd->pclk);
        gclk_rate = clk_get_rate(dd->gclk);

        /* PRESCAL = SELCK/(2*f_pdmic) - 1*/
        pclk_prescal = (u32)(pclk_rate/(f_pdmic << 1)) - 1;
        gclk_prescal = (u32)(gclk_rate/(f_pdmic << 1)) - 1;

        if ((pclk_prescal > PDMIC_MR_PRESCAL_MAX_VAL) ||
            (gclk_rate/((gclk_prescal + 1) << 1) <
             pclk_rate/((pclk_prescal + 1) << 1))) {
                mr_val = gclk_prescal << PDMIC_MR_PRESCAL_SHIFT;
                mr_val |= PDMIC_MR_CLKS_GCK << PDMIC_MR_CLKS_SHIFT;
        } else {
                mr_val = pclk_prescal << PDMIC_MR_PRESCAL_SHIFT;
                mr_val |= PDMIC_MR_CLKS_PCK << PDMIC_MR_CLKS_SHIFT;
        }

        snd_soc_component_update_bits(component, PDMIC_MR,
                PDMIC_MR_PRESCAL_MASK | PDMIC_MR_CLKS_MASK, mr_val);

        snd_soc_component_update_bits(component, PDMIC_DSPR0,
                PDMIC_DSPR0_OSR_MASK | PDMIC_DSPR0_SIZE_MASK, dspr0_val);

        return 0;
}

static int atmel_pdmic_cpu_dai_trigger(struct snd_pcm_substream *substream,
                                       int cmd, struct snd_soc_dai *cpu_dai)
{
        struct snd_soc_component *component = cpu_dai->component;
        u32 val;

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                val = PDMIC_CR_ENPDM_EN << PDMIC_CR_ENPDM_SHIFT;
                break;
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_SUSPEND:
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                val = PDMIC_CR_ENPDM_DIS << PDMIC_CR_ENPDM_SHIFT;
                break;
        default:
                return -EINVAL;
        }

        snd_soc_component_update_bits(component, PDMIC_CR, PDMIC_CR_ENPDM_MASK, val);

        return 0;
}

static const struct snd_soc_dai_ops atmel_pdmic_cpu_dai_ops = {
        .startup        = atmel_pdmic_cpu_dai_startup,
        .shutdown       = atmel_pdmic_cpu_dai_shutdown,
        .prepare        = atmel_pdmic_cpu_dai_prepare,
        .hw_params      = atmel_pdmic_cpu_dai_hw_params,
        .trigger        = atmel_pdmic_cpu_dai_trigger,
};


static struct snd_soc_dai_driver atmel_pdmic_cpu_dai = {
        .capture = {
                .stream_name    = "Capture",
                .channels_min   = 1,
                .channels_max   = 1,
                .rates          = SNDRV_PCM_RATE_KNOT,
                .formats        = ATMEL_PDMIC_FORMATS,
        },
        .ops = &atmel_pdmic_cpu_dai_ops,
};

static const struct snd_soc_component_driver atmel_pdmic_cpu_dai_component = {
        .name                   = "atmel-pdmic",
        .probe                  = atmel_pdmic_component_probe,
        .controls               = atmel_pdmic_snd_controls,
        .num_controls           = ARRAY_SIZE(atmel_pdmic_snd_controls),
        .idle_bias_on           = 1,
        .use_pmdown_time        = 1,
        .legacy_dai_naming      = 1,
};

/* ASoC sound card */
static int atmel_pdmic_asoc_card_init(struct device *dev,
                                struct snd_soc_card *card)
{
        struct snd_soc_dai_link *dai_link;
        struct atmel_pdmic *dd = snd_soc_card_get_drvdata(card);
        struct snd_soc_dai_link_component *comp;

        dai_link = devm_kzalloc(dev, sizeof(*dai_link), GFP_KERNEL);
        if (!dai_link)
                return -ENOMEM;

        comp = devm_kzalloc(dev, sizeof(*comp), GFP_KERNEL);
        if (!comp)
                return -ENOMEM;

        dai_link->cpus          = comp;
        dai_link->codecs        = &snd_soc_dummy_dlc;

        dai_link->num_cpus      = 1;
        dai_link->num_codecs    = 1;

        dai_link->name                  = "PDMIC";
        dai_link->stream_name           = "PDMIC PCM";
        dai_link->cpus->dai_name        = dev_name(dev);

        card->dai_link  = dai_link;
        card->num_links = 1;
        card->name      = dd->pdata->card_name;
        card->dev       = dev;

        return 0;
}

static void atmel_pdmic_get_sample_rate(struct atmel_pdmic *dd,
        unsigned int *rate_min, unsigned int *rate_max)
{
        u32 mic_min_freq = dd->pdata->mic_min_freq;
        u32 mic_max_freq = dd->pdata->mic_max_freq;
        u32 clk_max_rate = (u32)(clk_get_rate(dd->pclk) >> 1);
        u32 clk_min_rate = (u32)(clk_get_rate(dd->gclk) >> 8);

        if (mic_max_freq > clk_max_rate)
                mic_max_freq = clk_max_rate;

        if (mic_min_freq < clk_min_rate)
                mic_min_freq = clk_min_rate;

        *rate_min = DIV_ROUND_CLOSEST(mic_min_freq, 128);
        *rate_max = mic_max_freq >> 6;
}

/* PDMIC interrupt handler */
static irqreturn_t atmel_pdmic_interrupt(int irq, void *dev_id)
{
        struct atmel_pdmic *dd = (struct atmel_pdmic *)dev_id;
        u32 pdmic_isr;
        irqreturn_t ret = IRQ_NONE;

        regmap_read(dd->regmap, PDMIC_ISR, &pdmic_isr);

        if (pdmic_isr & PDMIC_ISR_OVRE) {
                regmap_update_bits(dd->regmap, PDMIC_CR, PDMIC_CR_ENPDM_MASK,
                                   PDMIC_CR_ENPDM_DIS << PDMIC_CR_ENPDM_SHIFT);

                snd_pcm_stop_xrun(dd->substream);

                ret = IRQ_HANDLED;
        }

        return ret;
}

/* regmap configuration */
#define ATMEL_PDMIC_REG_MAX    0x124
static const struct regmap_config atmel_pdmic_regmap_config = {
        .reg_bits       = 32,
        .reg_stride     = 4,
        .val_bits       = 32,
        .max_register   = ATMEL_PDMIC_REG_MAX,
};

static int atmel_pdmic_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct atmel_pdmic *dd;
        struct resource *res;
        void __iomem *io_base;
        const struct atmel_pdmic_pdata *pdata;
        struct snd_soc_card *card;
        unsigned int rate_min, rate_max;
        int ret;

        pdata = atmel_pdmic_dt_init(dev);
        if (IS_ERR(pdata))
                return PTR_ERR(pdata);

        dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL);
        if (!dd)
                return -ENOMEM;

        dd->pdata = pdata;
        dd->dev = dev;

        dd->irq = platform_get_irq(pdev, 0);
        if (dd->irq < 0)
                return dd->irq;

        dd->pclk = devm_clk_get(dev, "pclk");
        if (IS_ERR(dd->pclk)) {
                ret = PTR_ERR(dd->pclk);
                dev_err(dev, "failed to get peripheral clock: %d\n", ret);
                return ret;
        }

        dd->gclk = devm_clk_get(dev, "gclk");
        if (IS_ERR(dd->gclk)) {
                ret = PTR_ERR(dd->gclk);
                dev_err(dev, "failed to get GCK: %d\n", ret);
                return ret;
        }

        /* The gclk clock frequency must always be three times
         * lower than the pclk clock frequency
         */
        ret = clk_set_rate(dd->gclk, clk_get_rate(dd->pclk)/3);
        if (ret) {
                dev_err(dev, "failed to set GCK clock rate: %d\n", ret);
                return ret;
        }

        io_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
        if (IS_ERR(io_base))
                return PTR_ERR(io_base);

        dd->phy_base = res->start;

        dd->regmap = devm_regmap_init_mmio(dev, io_base,
                                           &atmel_pdmic_regmap_config);
        if (IS_ERR(dd->regmap)) {
                ret = PTR_ERR(dd->regmap);
                dev_err(dev, "failed to init register map: %d\n", ret);
                return ret;
        }

        ret =  devm_request_irq(dev, dd->irq, atmel_pdmic_interrupt, 0,
                                "PDMIC", (void *)dd);
        if (ret < 0) {
                dev_err(dev, "can't register ISR for IRQ %u (ret=%i)\n",
                        dd->irq, ret);
                return ret;
        }

        /* Get the minimal and maximal sample rate that the microphone supports */
        atmel_pdmic_get_sample_rate(dd, &rate_min, &rate_max);

        /* register cpu dai */
        atmel_pdmic_cpu_dai.capture.rate_min = rate_min;
        atmel_pdmic_cpu_dai.capture.rate_max = rate_max;
        ret = devm_snd_soc_register_component(dev,
                                              &atmel_pdmic_cpu_dai_component,
                                              &atmel_pdmic_cpu_dai, 1);
        if (ret) {
                dev_err(dev, "could not register CPU DAI: %d\n", ret);
                return ret;
        }

        /* register platform */
        ret = devm_snd_dmaengine_pcm_register(dev,
                                             &atmel_pdmic_dmaengine_pcm_config,
                                             0);
        if (ret) {
                dev_err(dev, "could not register platform: %d\n", ret);
                return ret;
        }

        /* register sound card */
        card = devm_kzalloc(dev, sizeof(*card), GFP_KERNEL);
        if (!card) {
                ret = -ENOMEM;
                goto unregister_codec;
        }

        snd_soc_card_set_drvdata(card, dd);

        ret = atmel_pdmic_asoc_card_init(dev, card);
        if (ret) {
                dev_err(dev, "failed to init sound card: %d\n", ret);
                goto unregister_codec;
        }

        ret = devm_snd_soc_register_card(dev, card);
        if (ret) {
                dev_err(dev, "failed to register sound card: %d\n", ret);
                goto unregister_codec;
        }

        return 0;

unregister_codec:
        return ret;
}

static struct platform_driver atmel_pdmic_driver = {
        .driver = {
                .name           = "atmel-pdmic",
                .of_match_table = atmel_pdmic_of_match,
                .pm             = &snd_soc_pm_ops,
        },
        .probe  = atmel_pdmic_probe,
};
module_platform_driver(atmel_pdmic_driver);

MODULE_DESCRIPTION("Atmel PDMIC driver under ALSA SoC architecture");
MODULE_AUTHOR("Songjun Wu <songjun.wu@atmel.com>");
MODULE_LICENSE("GPL v2");