// SPDX-License-Identifier: GPL-2.0-only
/*
 * dmic.c  --  SoC audio for Generic Digital MICs
 *
 * Author: Liam Girdwood <lrg@slimlogic.co.uk>
 */

#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/soc.h>
#include <sound/soc-dapm.h>

#define MAX_MODESWITCH_DELAY 70
static int modeswitch_delay;
module_param(modeswitch_delay, uint, 0644);

static int wakeup_delay;
module_param(wakeup_delay, uint, 0644);

struct dmic {
        struct gpio_desc *gpio_en;
        struct regulator *vref;
        int wakeup_delay;
        /* Delay after DMIC mode switch */
        int modeswitch_delay;
};

static int dmic_daiops_trigger(struct snd_pcm_substream *substream,
                               int cmd, struct snd_soc_dai *dai)
{
        struct snd_soc_component *component = dai->component;
        struct dmic *dmic = snd_soc_component_get_drvdata(component);

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_STOP:
                if (dmic->modeswitch_delay)
                        mdelay(dmic->modeswitch_delay);

                break;
        }

        return 0;
}

static const struct snd_soc_dai_ops dmic_dai_ops = {
        .trigger        = dmic_daiops_trigger,
};

static int dmic_aif_event(struct snd_soc_dapm_widget *w,
                          struct snd_kcontrol *kcontrol, int event) {
        struct snd_soc_component *component = snd_soc_dapm_to_component(w->dapm);
        struct dmic *dmic = snd_soc_component_get_drvdata(component);
        int ret = 0;

        switch (event) {
        case SND_SOC_DAPM_POST_PMU:
                if (dmic->gpio_en)
                        gpiod_set_value_cansleep(dmic->gpio_en, 1);

                if (dmic->vref) {
                        ret = regulator_enable(dmic->vref);
                        if (ret)
                                return ret;
                }

                if (dmic->wakeup_delay)
                        msleep(dmic->wakeup_delay);
                break;
        case SND_SOC_DAPM_POST_PMD:
                if (dmic->gpio_en)
                        gpiod_set_value_cansleep(dmic->gpio_en, 0);

                if (dmic->vref)
                        ret = regulator_disable(dmic->vref);

                break;
        }

        return ret;
}

static struct snd_soc_dai_driver dmic_dai = {
        .name = "dmic-hifi",
        .capture = {
                .stream_name = "Capture",
                .channels_min = 1,
                .channels_max = 8,
                .rates = SNDRV_PCM_RATE_CONTINUOUS,
                .formats = SNDRV_PCM_FMTBIT_S32_LE
                        | SNDRV_PCM_FMTBIT_S24_LE
                        | SNDRV_PCM_FMTBIT_S16_LE
                        | SNDRV_PCM_FMTBIT_DSD_U8
                        | SNDRV_PCM_FMTBIT_DSD_U16_LE
                        | SNDRV_PCM_FMTBIT_DSD_U32_LE
                        | SNDRV_PCM_FMTBIT_DSD_U16_BE
                        | SNDRV_PCM_FMTBIT_DSD_U32_BE,
        },
        .ops    = &dmic_dai_ops,
};

static int dmic_component_probe(struct snd_soc_component *component)
{
        struct dmic *dmic;

        dmic = devm_kzalloc(component->dev, sizeof(*dmic), GFP_KERNEL);
        if (!dmic)
                return -ENOMEM;

        dmic->vref = devm_regulator_get_optional(component->dev, "vref");
        if (IS_ERR(dmic->vref)) {
                if (PTR_ERR(dmic->vref) != -ENODEV)
                        return dev_err_probe(component->dev, PTR_ERR(dmic->vref),
                                             "Failed to get vref\n");
                dmic->vref = NULL;
        }

        dmic->gpio_en = devm_gpiod_get_optional(component->dev,
                                                "dmicen", GPIOD_OUT_LOW);
        if (IS_ERR(dmic->gpio_en))
                return PTR_ERR(dmic->gpio_en);

        device_property_read_u32(component->dev, "wakeup-delay-ms",
                                 &dmic->wakeup_delay);
        device_property_read_u32(component->dev, "modeswitch-delay-ms",
                                 &dmic->modeswitch_delay);
        if (wakeup_delay)
                dmic->wakeup_delay  = wakeup_delay;
        if (modeswitch_delay)
                dmic->modeswitch_delay  = modeswitch_delay;

        if (dmic->modeswitch_delay > MAX_MODESWITCH_DELAY)
                dmic->modeswitch_delay = MAX_MODESWITCH_DELAY;

        snd_soc_component_set_drvdata(component, dmic);

        return 0;
}

static const struct snd_soc_dapm_widget dmic_dapm_widgets[] = {
        SND_SOC_DAPM_AIF_OUT_E("DMIC AIF", "Capture", 0,
                               SND_SOC_NOPM, 0, 0, dmic_aif_event,
                               SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
        SND_SOC_DAPM_INPUT("DMic"),
};

static const struct snd_soc_dapm_route intercon[] = {
        {"DMIC AIF", NULL, "DMic"},
};

static const struct snd_soc_component_driver soc_dmic = {
        .probe                  = dmic_component_probe,
        .dapm_widgets           = dmic_dapm_widgets,
        .num_dapm_widgets       = ARRAY_SIZE(dmic_dapm_widgets),
        .dapm_routes            = intercon,
        .num_dapm_routes        = ARRAY_SIZE(intercon),
        .idle_bias_on           = 1,
        .use_pmdown_time        = 1,
        .endianness             = 1,
};

static int dmic_dev_probe(struct platform_device *pdev)
{
        int err;
        u32 chans;
        struct snd_soc_dai_driver *dai_drv = &dmic_dai;

        if (pdev->dev.of_node) {
                err = of_property_read_u32(pdev->dev.of_node, "num-channels", &chans);
                if (err && (err != -EINVAL))
                        return err;

                if (!err) {
                        if (chans < 1 || chans > 8)
                                return -EINVAL;

                        dai_drv = devm_kzalloc(&pdev->dev, sizeof(*dai_drv), GFP_KERNEL);
                        if (!dai_drv)
                                return -ENOMEM;

                        memcpy(dai_drv, &dmic_dai, sizeof(*dai_drv));
                        dai_drv->capture.channels_max = chans;
                }
        }

        return devm_snd_soc_register_component(&pdev->dev,
                        &soc_dmic, dai_drv, 1);
}

MODULE_ALIAS("platform:dmic-codec");

static const struct of_device_id dmic_dev_match[] = {
        {.compatible = "dmic-codec"},
        {}
};
MODULE_DEVICE_TABLE(of, dmic_dev_match);

static struct platform_driver dmic_driver = {
        .driver = {
                .name = "dmic-codec",
                .of_match_table = dmic_dev_match,
        },
        .probe = dmic_dev_probe,
};

module_platform_driver(dmic_driver);

MODULE_DESCRIPTION("Generic DMIC driver");
MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
MODULE_LICENSE("GPL");