sound/soc/codecs/aw8738.c

Source file repositories/reference/linux-study-clean/sound/soc/codecs/aw8738.c

File Facts

System
Linux kernel
Corpus path
sound/soc/codecs/aw8738.c
Extension
.c
Size
2621 bytes
Lines
105
Domain
Driver Families
Bucket
sound/soc
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct aw8738_priv {
	struct gpio_desc *gpiod_mode;
	unsigned int mode;
};

static int aw8738_drv_event(struct snd_soc_dapm_widget *w,
			    struct snd_kcontrol *kcontrol, int event)
{
	struct snd_soc_component *c = snd_soc_dapm_to_component(w->dapm);
	struct aw8738_priv *aw = snd_soc_component_get_drvdata(c);
	int i;

	switch (event) {
	case SND_SOC_DAPM_POST_PMU:
		for (i = 0; i < aw->mode; i++) {
			gpiod_set_value_cansleep(aw->gpiod_mode, 0);
			udelay(2);
			gpiod_set_value_cansleep(aw->gpiod_mode, 1);
			udelay(2);
		}
		msleep(40);
		break;
	case SND_SOC_DAPM_PRE_PMD:
		gpiod_set_value_cansleep(aw->gpiod_mode, 0);
		usleep_range(1000, 2000);
		break;
	default:
		WARN(1, "Unexpected event");
		return -EINVAL;
	}

	return 0;
}

static const struct snd_soc_dapm_widget aw8738_dapm_widgets[] = {
	SND_SOC_DAPM_INPUT("IN"),
	SND_SOC_DAPM_OUT_DRV_E("DRV", SND_SOC_NOPM, 0, 0, NULL, 0, aw8738_drv_event,
			       SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),
	SND_SOC_DAPM_OUTPUT("OUT"),
};

static const struct snd_soc_dapm_route aw8738_dapm_routes[] = {
	{ "DRV", NULL, "IN" },
	{ "OUT", NULL, "DRV" },
};

static const struct snd_soc_component_driver aw8738_component_driver = {
	.dapm_widgets = aw8738_dapm_widgets,
	.num_dapm_widgets = ARRAY_SIZE(aw8738_dapm_widgets),
	.dapm_routes = aw8738_dapm_routes,
	.num_dapm_routes = ARRAY_SIZE(aw8738_dapm_routes),
};

static int aw8738_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct aw8738_priv *aw;
	int ret;

	aw = devm_kzalloc(dev, sizeof(*aw), GFP_KERNEL);
	if (!aw)
		return -ENOMEM;
	platform_set_drvdata(pdev, aw);

	aw->gpiod_mode = devm_gpiod_get(dev, "mode", GPIOD_OUT_LOW);
	if (IS_ERR(aw->gpiod_mode))
		return dev_err_probe(dev, PTR_ERR(aw->gpiod_mode),
				     "Failed to get 'mode' gpio");

	ret = device_property_read_u32(dev, "awinic,mode", &aw->mode);
	if (ret)
		return -EINVAL;

	return devm_snd_soc_register_component(&pdev->dev,
					       &aw8738_component_driver,
					       NULL, 0);
}

#ifdef CONFIG_OF
static const struct of_device_id aw8738_of_match[] = {
	{ .compatible = "awinic,aw8738" },
	{ }
};
MODULE_DEVICE_TABLE(of, aw8738_of_match);
#endif

static struct platform_driver aw8738_driver = {
	.probe	= aw8738_probe,
	.driver = {
		.name = "aw8738",

Annotation

Implementation Notes