drivers/power/reset/gemini-poweroff.c

Source file repositories/reference/linux-study-clean/drivers/power/reset/gemini-poweroff.c

File Facts

System
Linux kernel
Corpus path
drivers/power/reset/gemini-poweroff.c
Extension
.c
Size
4355 bytes
Lines
176
Domain
Driver Families
Bucket
drivers/power
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 gemini_powercon {
        struct device           *dev;
        void __iomem            *base;
};

static irqreturn_t gemini_powerbutton_interrupt(int irq, void *data)
{
	struct gemini_powercon *gpw = data;
	u32 val;

	/* ACK the IRQ */
	val = readl(gpw->base + GEMINI_PWC_CTRLREG);
	val |= GEMINI_CTRL_IRQ_CLR;
	writel(val, gpw->base + GEMINI_PWC_CTRLREG);

	val = readl(gpw->base + GEMINI_PWC_STATREG);
	val &= 0x70U;
	switch (val) {
	case GEMINI_STAT_CIR:
		/*
		 * We do not yet have a driver for the infrared
		 * controller so it can cause spurious poweroff
		 * events. Ignore those for now.
		 */
		dev_info(gpw->dev, "infrared poweroff - ignored\n");
		break;
	case GEMINI_STAT_RTC:
		dev_info(gpw->dev, "RTC poweroff\n");
		orderly_poweroff(true);
		break;
	case GEMINI_STAT_POWERBUTTON:
		dev_info(gpw->dev, "poweroff button pressed\n");
		orderly_poweroff(true);
		break;
	default:
		dev_info(gpw->dev, "other power management IRQ\n");
		break;
	}

	return IRQ_HANDLED;
}

static int gemini_poweroff(struct sys_off_data *data)
{
	struct gemini_powercon *gpw = data->cb_data;
	u32 val;

	dev_crit(gpw->dev, "Gemini power off\n");
	val = readl(gpw->base + GEMINI_PWC_CTRLREG);
	val |= GEMINI_CTRL_ENABLE | GEMINI_CTRL_IRQ_CLR;
	writel(val, gpw->base + GEMINI_PWC_CTRLREG);

	val &= ~GEMINI_CTRL_ENABLE;
	val |= GEMINI_CTRL_SHUTDOWN;
	writel(val, gpw->base + GEMINI_PWC_CTRLREG);

	return NOTIFY_DONE;
}

static int gemini_poweroff_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct gemini_powercon *gpw;
	u32 val;
	int irq;
	int ret;

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

	gpw->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(gpw->base))
		return PTR_ERR(gpw->base);

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	gpw->dev = dev;

	val = readl(gpw->base + GEMINI_PWC_IDREG);
	val &= 0xFFFFFF00U;
	if (val != GEMINI_PWC_ID) {
		dev_err(dev, "wrong power controller ID: %08x\n",
			val);
		return -ENODEV;
	}

	/*

Annotation

Implementation Notes