static acpi_status acpi_gpiochip_alloc_event()

in gpiolib-acpi.c [370:469]

• 87 lines of code
• 16 McCabe index (conditional complexity)

static acpi_status acpi_gpiochip_alloc_event(struct acpi_resource *ares,
					     void *context)
{
	struct acpi_gpio_chip *acpi_gpio = context;
	struct gpio_chip *chip = acpi_gpio->chip;
	struct acpi_resource_gpio *agpio;
	acpi_handle handle, evt_handle;
	struct acpi_gpio_event *event;
	irq_handler_t handler = NULL;
	struct gpio_desc *desc;
	int ret, pin, irq;

	if (!acpi_gpio_get_irq_resource(ares, &agpio))
		return AE_OK;

	handle = ACPI_HANDLE(chip->parent);
	pin = agpio->pin_table[0];

	if (pin <= 255) {
		char ev_name[5];
		sprintf(ev_name, "_%c%02hhX",
			agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L',
			pin);
		if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
			handler = acpi_gpio_irq_handler;
	}
	if (!handler) {
		if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
			handler = acpi_gpio_irq_handler_evt;
	}
	if (!handler)
		return AE_OK;

	desc = acpi_request_own_gpiod(chip, agpio, 0, "ACPI:Event");
	if (IS_ERR(desc)) {
		dev_err(chip->parent,
			"Failed to request GPIO for pin 0x%04X, err %ld\n",
			pin, PTR_ERR(desc));
		return AE_OK;
	}

	ret = gpiochip_lock_as_irq(chip, pin);
	if (ret) {
		dev_err(chip->parent,
			"Failed to lock GPIO pin 0x%04X as interrupt, err %d\n",
			pin, ret);
		goto fail_free_desc;
	}

	irq = gpiod_to_irq(desc);
	if (irq < 0) {
		dev_err(chip->parent,
			"Failed to translate GPIO pin 0x%04X to IRQ, err %d\n",
			pin, irq);
		goto fail_unlock_irq;
	}

	event = kzalloc(sizeof(*event), GFP_KERNEL);
	if (!event)
		goto fail_unlock_irq;

	event->irqflags = IRQF_ONESHOT;
	if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
		if (agpio->polarity == ACPI_ACTIVE_HIGH)
			event->irqflags |= IRQF_TRIGGER_HIGH;
		else
			event->irqflags |= IRQF_TRIGGER_LOW;
	} else {
		switch (agpio->polarity) {
		case ACPI_ACTIVE_HIGH:
			event->irqflags |= IRQF_TRIGGER_RISING;
			break;
		case ACPI_ACTIVE_LOW:
			event->irqflags |= IRQF_TRIGGER_FALLING;
			break;
		default:
			event->irqflags |= IRQF_TRIGGER_RISING |
					   IRQF_TRIGGER_FALLING;
			break;
		}
	}

	event->handle = evt_handle;
	event->handler = handler;
	event->irq = irq;
	event->irq_is_wake = acpi_gpio_irq_is_wake(chip->parent, agpio);
	event->pin = pin;
	event->desc = desc;

	list_add_tail(&event->node, &acpi_gpio->events);

	return AE_OK;

fail_unlock_irq:
	gpiochip_unlock_as_irq(chip, pin);
fail_free_desc:
	gpiochip_free_own_desc(desc);

	return AE_OK;
}