drivers/acpi/evged.c

Source file repositories/reference/linux-study-clean/drivers/acpi/evged.c

File Facts

System
Linux kernel
Corpus path
drivers/acpi/evged.c
Extension
.c
Size
4653 bytes
Lines
196
Domain
Driver Families
Bucket
drivers/acpi
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 acpi_ged_device {
	struct device *dev;
	struct list_head event_list;
};

struct acpi_ged_event {
	struct list_head node;
	struct device *dev;
	unsigned int gsi;
	unsigned int irq;
	acpi_handle handle;
};

static irqreturn_t acpi_ged_irq_handler(int irq, void *data)
{
	struct acpi_ged_event *event = data;
	acpi_status acpi_ret;

	acpi_ret = acpi_execute_simple_method(event->handle, NULL, event->gsi);
	if (ACPI_FAILURE(acpi_ret))
		dev_err_once(event->dev, "IRQ method execution failed\n");

	return IRQ_HANDLED;
}

static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,
					      void *context)
{
	struct acpi_ged_event *event;
	unsigned int irq;
	unsigned int gsi;
	unsigned int irqflags = IRQF_ONESHOT;
	struct acpi_ged_device *geddev = context;
	struct device *dev = geddev->dev;
	acpi_handle handle = ACPI_HANDLE(dev);
	acpi_handle evt_handle;
	struct resource r;
	struct acpi_resource_irq *p = &ares->data.irq;
	struct acpi_resource_extended_irq *pext = &ares->data.extended_irq;
	char ev_name[5];
	u8 trigger;

	if (ares->type == ACPI_RESOURCE_TYPE_END_TAG)
		return AE_OK;

	if (!acpi_dev_resource_interrupt(ares, 0, &r)) {
		dev_err(dev, "unable to parse IRQ resource\n");
		return AE_ERROR;
	}
	if (ares->type == ACPI_RESOURCE_TYPE_IRQ) {
		gsi = p->interrupts[0];
		trigger = p->triggering;
	} else {
		gsi = pext->interrupts[0];
		trigger = pext->triggering;
	}

	irq = r.start;

	switch (gsi) {
	case 0 ... 255:
		sprintf(ev_name, "_%c%02X",
			trigger == ACPI_EDGE_SENSITIVE ? 'E' : 'L', gsi);

		if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
			break;
		fallthrough;
	default:
		if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
			break;

		dev_err(dev, "cannot locate _EVT method\n");
		return AE_ERROR;
	}

	event = devm_kzalloc(dev, sizeof(*event), GFP_KERNEL);
	if (!event)
		return AE_ERROR;

	event->gsi = gsi;
	event->dev = dev;
	event->irq = irq;
	event->handle = evt_handle;

	if (r.flags & IORESOURCE_IRQ_SHAREABLE)
		irqflags |= IRQF_SHARED;

	if (request_threaded_irq(irq, NULL, acpi_ged_irq_handler,
				 irqflags, "ACPI:Ged", event)) {
		dev_err(dev, "failed to setup event handler for irq %u\n", irq);

Annotation

Implementation Notes