/*
 * ALSA SoC driver for
 *    Asahi Kasei AK5386 Single-ended 24-Bit 192kHz delta-sigma ADC
 *
 * (c) 2013 Daniel Mack <zonque@gmail.com>
 *
 * 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/slab.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/of_device.h>
#include <linux/regulator/consumer.h>
#include <sound/soc.h>
#include <sound/pcm.h>
#include <sound/initval.h>

static const char * const supply_names[] = {
        "va", "vd"
};

struct ak5386_priv {
        int reset_gpio;
        struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
};

static const struct snd_soc_dapm_widget ak5386_dapm_widgets[] = {
SND_SOC_DAPM_INPUT("AINL"),
SND_SOC_DAPM_INPUT("AINR"),
};

static const struct snd_soc_dapm_route ak5386_dapm_routes[] = {
        { "Capture", NULL, "AINL" },
        { "Capture", NULL, "AINR" },
};

static int ak5386_soc_probe(struct snd_soc_codec *codec)
{
        struct ak5386_priv *priv = snd_soc_codec_get_drvdata(codec);
        return regulator_bulk_enable(ARRAY_SIZE(priv->supplies), priv->supplies);
}

static int ak5386_soc_remove(struct snd_soc_codec *codec)
{
        struct ak5386_priv *priv = snd_soc_codec_get_drvdata(codec);
        regulator_bulk_disable(ARRAY_SIZE(priv->supplies), priv->supplies);
        return 0;
}

#ifdef CONFIG_PM
static int ak5386_soc_suspend(struct snd_soc_codec *codec)
{
        struct ak5386_priv *priv = snd_soc_codec_get_drvdata(codec);
        regulator_bulk_disable(ARRAY_SIZE(priv->supplies), priv->supplies);
        return 0;
}

static int ak5386_soc_resume(struct snd_soc_codec *codec)
{
        struct ak5386_priv *priv = snd_soc_codec_get_drvdata(codec);
        return regulator_bulk_enable(ARRAY_SIZE(priv->supplies), priv->supplies);
}
#else
#define ak5386_soc_suspend      NULL
#define ak5386_soc_resume       NULL
#endif /* CONFIG_PM */

static struct snd_soc_codec_driver soc_codec_ak5386 = {
        .probe = ak5386_soc_probe,
        .remove = ak5386_soc_remove,
        .suspend = ak5386_soc_suspend,
        .resume = ak5386_soc_resume,
        .dapm_widgets = ak5386_dapm_widgets,
        .num_dapm_widgets = ARRAY_SIZE(ak5386_dapm_widgets),
        .dapm_routes = ak5386_dapm_routes,
        .num_dapm_routes = ARRAY_SIZE(ak5386_dapm_routes),
};

static int ak5386_set_dai_fmt(struct snd_soc_dai *codec_dai,
                              unsigned int format)
{
        struct snd_soc_codec *codec = codec_dai->codec;

        format &= SND_SOC_DAIFMT_FORMAT_MASK;
        if (format != SND_SOC_DAIFMT_LEFT_J &&
            format != SND_SOC_DAIFMT_I2S) {
                dev_err(codec->dev, "Invalid DAI format\n");
                return -EINVAL;
        }

        return 0;
}

static int ak5386_hw_params(struct snd_pcm_substream *substream,
                            struct snd_pcm_hw_params *params,
                            struct snd_soc_dai *dai)
{
        struct snd_soc_codec *codec = dai->codec;
        struct ak5386_priv *priv = snd_soc_codec_get_drvdata(codec);

        /*
         * From the datasheet:
         *
         * All external clocks (MCLK, SCLK and LRCK) must be present unless
         * PDN pin = “L”. If these clocks are not provided, the AK5386 may
         * draw excess current due to its use of internal dynamically
         * refreshed logic. If the external clocks are not present, place
         * the AK5386 in power-down mode (PDN pin = “L”).
         */

        if (gpio_is_valid(priv->reset_gpio))
                gpio_set_value(priv->reset_gpio, 1);

        return 0;
}

static int ak5386_hw_free(struct snd_pcm_substream *substream,
                          struct snd_soc_dai *dai)
{
        struct snd_soc_codec *codec = dai->codec;
        struct ak5386_priv *priv = snd_soc_codec_get_drvdata(codec);

        if (gpio_is_valid(priv->reset_gpio))
                gpio_set_value(priv->reset_gpio, 0);

        return 0;
}

static const struct snd_soc_dai_ops ak5386_dai_ops = {
        .set_fmt        = ak5386_set_dai_fmt,
        .hw_params      = ak5386_hw_params,
        .hw_free        = ak5386_hw_free,
};

static struct snd_soc_dai_driver ak5386_dai = {
        .name           = "ak5386-hifi",
        .capture        = {
                .stream_name    = "Capture",
                .channels_min   = 1,
                .channels_max   = 2,
                .rates          = SNDRV_PCM_RATE_8000_192000,
                .formats        = SNDRV_PCM_FMTBIT_S8     |
                                  SNDRV_PCM_FMTBIT_S16_LE |
                                  SNDRV_PCM_FMTBIT_S24_LE |
                                  SNDRV_PCM_FMTBIT_S24_3LE,
        },
        .ops    = &ak5386_dai_ops,
};

#ifdef CONFIG_OF
static const struct of_device_id ak5386_dt_ids[] = {
        { .compatible = "asahi-kasei,ak5386", },
        { }
};
MODULE_DEVICE_TABLE(of, ak5386_dt_ids);
#endif

static int ak5386_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct ak5386_priv *priv;
        int ret, i;

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

        priv->reset_gpio = -EINVAL;
        dev_set_drvdata(dev, priv);

        for (i = 0; i < ARRAY_SIZE(supply_names); i++)
                priv->supplies[i].supply = supply_names[i];

        ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(priv->supplies),
                                      priv->supplies);
        if (ret < 0)
                return ret;

        if (of_match_device(of_match_ptr(ak5386_dt_ids), dev))
                priv->reset_gpio = of_get_named_gpio(dev->of_node,
                                                      "reset-gpio", 0);

        if (gpio_is_valid(priv->reset_gpio))
                if (devm_gpio_request_one(dev, priv->reset_gpio,
                                          GPIOF_OUT_INIT_LOW,
                                          "AK5386 Reset"))
                        priv->reset_gpio = -EINVAL;

        return snd_soc_register_codec(dev, &soc_codec_ak5386,
                                      &ak5386_dai, 1);
}

static int ak5386_remove(struct platform_device *pdev)
{
        snd_soc_unregister_codec(&pdev->dev);
        return 0;
}

static struct platform_driver ak5386_driver = {
        .probe          = ak5386_probe,
        .remove         = ak5386_remove,
        .driver         = {
                .name   = "ak5386",
                .of_match_table = of_match_ptr(ak5386_dt_ids),
        },
};

module_platform_driver(ak5386_driver);

MODULE_DESCRIPTION("ASoC driver for AK5386 ADC");
MODULE_AUTHOR("Daniel Mack <zonque@gmail.com>");
MODULE_LICENSE("GPL");