root/sound/soc/codecs/rt9123p.c
// SPDX-License-Identifier: GPL-2.0-only
//
// rt9123p.c -- RT9123 (HW Mode) ALSA SoC Codec driver
//
// Author: ChiYuan Huang <cy_huang@richtek.com>

#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <sound/pcm.h>
#include <sound/soc.h>
#include <sound/soc-dai.h>
#include <sound/soc-dapm.h>

struct rt9123p_priv {
        struct gpio_desc *enable;
        unsigned int enable_delay;
        int enable_switch;
};

static int rt9123p_daiops_trigger(struct snd_pcm_substream *substream, int cmd,
                                  struct snd_soc_dai *dai)
{
        struct snd_soc_component *comp = dai->component;
        struct rt9123p_priv *rt9123p = snd_soc_component_get_drvdata(comp);

        if (!rt9123p->enable)
                return 0;

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                mdelay(rt9123p->enable_delay);
                if (rt9123p->enable_switch) {
                        gpiod_set_value(rt9123p->enable, 1);
                        dev_dbg(comp->dev, "set enable to 1");
                }
                break;
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_SUSPEND:
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                gpiod_set_value(rt9123p->enable, 0);
                dev_dbg(comp->dev, "set enable to 0");
                break;
        default:
                break;
        }

        return 0;
}

static int rt9123p_enable_event(struct snd_soc_dapm_widget *w, struct snd_kcontrol *kcontrol,
                                int event)
{
        struct snd_soc_component *comp = snd_soc_dapm_to_component(w->dapm);
        struct rt9123p_priv *rt9123p = snd_soc_component_get_drvdata(comp);

        if (event & SND_SOC_DAPM_POST_PMU)
                rt9123p->enable_switch = 1;
        else if (event & SND_SOC_DAPM_POST_PMD)
                rt9123p->enable_switch = 0;

        return 0;
}

static const struct snd_soc_dapm_widget rt9123p_dapm_widgets[] = {
        SND_SOC_DAPM_OUTPUT("SPK"),
        SND_SOC_DAPM_OUT_DRV_E("Amp Drv", SND_SOC_NOPM, 0, 0, NULL, 0, rt9123p_enable_event,
                               SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
};

static const struct snd_soc_dapm_route rt9123p_dapm_routes[] = {
        {"Amp Drv", NULL, "HiFi Playback"},
        {"SPK", NULL, "Amp Drv"},
};

static const struct snd_soc_component_driver rt9123p_comp_driver = {
        .dapm_widgets           = rt9123p_dapm_widgets,
        .num_dapm_widgets       = ARRAY_SIZE(rt9123p_dapm_widgets),
        .dapm_routes            = rt9123p_dapm_routes,
        .num_dapm_routes        = ARRAY_SIZE(rt9123p_dapm_routes),
        .idle_bias_on           = 1,
        .use_pmdown_time        = 1,
        .endianness             = 1,
};

static const struct snd_soc_dai_ops rt9123p_dai_ops = {
        .trigger        = rt9123p_daiops_trigger,
};

static struct snd_soc_dai_driver rt9123p_dai_driver = {
        .name = "HiFi",
        .playback = {
                .stream_name    = "HiFi Playback",
                .formats        = SNDRV_PCM_FMTBIT_S16 | SNDRV_PCM_FMTBIT_S24 |
                                  SNDRV_PCM_FMTBIT_S32,
                .rates          = SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |
                                  SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_24000 |
                                  SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
                                  SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 |
                                  SNDRV_PCM_RATE_96000,
                .rate_min       = 8000,
                .rate_max       = 96000,
                .channels_min   = 1,
                .channels_max   = 2,
        },
        .ops    = &rt9123p_dai_ops,
};

static int rt9123p_platform_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct rt9123p_priv *rt9123p;
        int ret;

        rt9123p = devm_kzalloc(dev, sizeof(*rt9123p), GFP_KERNEL);
        if (!rt9123p)
                return -ENOMEM;

        rt9123p->enable = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
        if (IS_ERR(rt9123p->enable))
                return PTR_ERR(rt9123p->enable);

        ret = device_property_read_u32(dev, "enable-delay-ms", &rt9123p->enable_delay);
        if (ret) {
                rt9123p->enable_delay = 0;
                dev_dbg(dev, "no optional property 'enable-delay-ms' found, default: no delay\n");
        }

        platform_set_drvdata(pdev, rt9123p);

        return devm_snd_soc_register_component(dev, &rt9123p_comp_driver, &rt9123p_dai_driver, 1);
}

#ifdef CONFIG_OF
static const struct of_device_id rt9123p_device_id[] = {
        { .compatible = "richtek,rt9123p" },
        {}
};
MODULE_DEVICE_TABLE(of, rt9123p_device_id);
#endif

#ifdef CONFIG_ACPI
static const struct acpi_device_id rt9123p_acpi_match[] = {
        { "RT9123P", 0 },
        {}
};
MODULE_DEVICE_TABLE(acpi, rt9123p_acpi_match);
#endif

static struct platform_driver rt9123p_platform_driver = {
        .driver = {
                .name = "rt9123p",
                .of_match_table = of_match_ptr(rt9123p_device_id),
                .acpi_match_table = ACPI_PTR(rt9123p_acpi_match),
        },
        .probe  = rt9123p_platform_probe,
};
module_platform_driver(rt9123p_platform_driver);

MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
MODULE_DESCRIPTION("ASoC rt9123p Driver");
MODULE_LICENSE("GPL");