/*
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <sound/pcm.h>
#include <sound/soc.h>
#include <linux/io.h>

#include <asm/mach-types.h>

static int snd_rpi_bathat_init(struct snd_soc_pcm_runtime *rtd)
{
    struct snd_soc_codec *codec = rtd->codec;
    dev_info(codec->dev, "Bathat init");
    return 0;
}

/* CS4270 */
static int snd_rpi_bathat_startup(struct snd_pcm_substream *substream)
{
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct snd_soc_dai *codec_dai = rtd->codec_dai;
    struct snd_soc_codec *codec = rtd->codec;

    int sysclk = 24576000;
    int ret = snd_soc_dai_set_sysclk(codec_dai, 0, sysclk, 0);

    dev_info(codec->dev, "Bathat startup");

    if (ret < 0) {
        dev_err(codec->dev, "Unable to set CS4270 system clock.");
    }

    return ret;
}

static void snd_rpi_bathat_shutdown(struct snd_pcm_substream *substream) {
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct snd_soc_codec *codec = rtd->codec;
    dev_info(codec->dev, "Bathat shutdown");
}

static int snd_rpi_bathat_hw_params(struct snd_pcm_substream *substream,
                     struct snd_pcm_hw_params *params)
{
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct snd_soc_dai *codec_dai = rtd->codec_dai;
    struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
    struct snd_soc_codec *codec = rtd->codec;

    int sysclk = 24576000;
    int ret = snd_soc_dai_set_sysclk(codec_dai, 0, sysclk, 0);

    dev_info(codec->dev, "Bathat HW params");

    if (ret < 0) {
        dev_err(codec->dev, "Unable to set CS4270 system clock.");
    }

    return ret;
}

static struct snd_soc_ops snd_rpi_bathat_ops = {
    .startup = snd_rpi_bathat_startup,
    .shutdown = snd_rpi_bathat_shutdown,
    .hw_params = snd_rpi_bathat_hw_params,
};

static struct snd_soc_dai_link snd_soc_rpi_bathat_dai[] = {
{
    .name       = "BatHat",
    .stream_name    = "BatHat",
    .cpu_dai_name   = "bcm2708-i2s.0",
    .codec_dai_name = "cs4270-hifi",
    .platform_name  = "bcm2708-pcm-audio.0",
    .codec_name = "cs4270.1-0048",
    .dai_fmt    = SND_SOC_DAIFMT_I2S
                | SND_SOC_DAIFMT_NB_NF
                | SND_SOC_DAIFMT_CBS_CFS,
    .ops        = &snd_rpi_bathat_ops,
    .init = snd_rpi_bathat_init,
}
};

static struct snd_soc_card snd_rpi_bathat = {
    .name       = "snd_rpi_bathat",
    .owner      = THIS_MODULE,
    .dai_link   = snd_soc_rpi_bathat_dai,
    .num_links  = ARRAY_SIZE(snd_soc_rpi_bathat_dai),
};

static int snd_rpi_bathat_probe(struct platform_device *pdev)
{
    int ret = 0;

    snd_rpi_bathat.dev = &pdev->dev;
    dev_info(&pdev->dev, "Bathat probe");
    if (pdev->dev.of_node) {
        struct device_node *i2s_node;
        struct snd_soc_dai_link *dai = &snd_soc_rpi_bathat_dai[0];
        i2s_node = of_parse_phandle(pdev->dev.of_node,
                    "i2s-controller", 0);

        dev_info(&pdev->dev, "Bathat has of_node");
        if (i2s_node) {
            dev_info(&pdev->dev, "Bathat has i2s_node");
            dai->cpu_dai_name = NULL;
            dai->cpu_of_node = i2s_node;
            dai->platform_name = NULL;
            dai->platform_of_node = i2s_node;
        }
    }

    ret = snd_soc_register_card(&snd_rpi_bathat);
    if (ret)
        dev_err(&pdev->dev,
            "snd_soc_register_card() failed: %d\n", ret);

    return ret;
}

static int snd_rpi_bathat_remove(struct platform_device *pdev)
{
    dev_info(&pdev->dev, "Bathat remove");
    return snd_soc_unregister_card(&snd_rpi_bathat);
}

static const struct of_device_id snd_rpi_bathat_of_match[] = {
    { .compatible = "bathat", },
    {},
};
MODULE_DEVICE_TABLE(of, snd_rpi_bathat_of_match);

static struct platform_driver snd_rpi_bathat_driver = {
    .driver = {
        .name   = "snd-rpi-bathat",
        .owner  = THIS_MODULE,
        .of_match_table = snd_rpi_bathat_of_match,
    },
    .probe    = snd_rpi_bathat_probe,
    .remove  = snd_rpi_bathat_remove,
};

module_platform_driver(snd_rpi_bathat_driver);

/* Module information */
MODULE_AUTHOR("REDACTED");
MODULE_DESCRIPTION("ASoC Driver for Raspberry Pi connected to BatHat board (CS4270)");
MODULE_LICENSE("GPL");