[PATCH 12/12] gpiolib: acpi: Decouple Event and Interrupt handling from core

["Marco Scardovi (scardracs)" <mscardovi95@gmail.com>]

Assisted-by: Antigravity:gemini-3-flash
Signed-off-by: Marco Scardovi <mscardovi95@gmail.com>
---
 drivers/gpio/gpiolib-acpi-core.c | 285 +------------------------------
 1 file changed, 1 insertion(+), 284 deletions(-)

diff --git a/drivers/gpio/gpiolib-acpi-core.c b/drivers/gpio/gpiolib-acpi-core.c
index b8976a0c798e..99b7b0409810 100644
--- a/drivers/gpio/gpiolib-acpi-core.c
+++ b/drivers/gpio/gpiolib-acpi-core.c
@@ -106,25 +106,7 @@ static struct gpio_desc *acpi_get_gpiod(char *path, unsigned int pin)
 	return gpio_device_get_desc(gdev, pin);
 }
 
-static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
-{
-	struct acpi_gpio_event *event = data;
-
-	acpi_evaluate_object(event->handle, NULL, NULL, NULL);
-
-	return IRQ_HANDLED;
-}
-
-static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
-{
-	struct acpi_gpio_event *event = data;
-
-	acpi_execute_simple_method(event->handle, NULL, event->pin);
-
-	return IRQ_HANDLED;
-}
-
-static void acpi_gpio_chip_dh(acpi_handle handle, void *data)
+void acpi_gpio_chip_dh(acpi_handle handle, void *data)
 {
 	/* The address of this function is used as a key. */
 }
@@ -172,52 +154,7 @@ bool acpi_gpio_get_io_resource(struct acpi_resource *ares,
 }
 EXPORT_SYMBOL_GPL(acpi_gpio_get_io_resource);
 
-static void acpi_gpiochip_request_irq(struct acpi_gpio_chip *acpi_gpio,
-				      struct acpi_gpio_event *event)
-{
-	struct device *parent = acpi_gpio->chip->parent;
-	int ret, value;
-
-	ret = request_threaded_irq(event->irq, NULL, event->handler,
-				   event->irqflags | IRQF_ONESHOT, "ACPI:Event", event);
-	if (ret) {
-		dev_err(parent, "Failed to setup interrupt handler for %d\n", event->irq);
-		return;
-	}
-
-	if (event->irq_is_wake)
-		enable_irq_wake(event->irq);
 
-	event->irq_requested = true;
-
-	/*
-	 * Make sure we trigger the initial state of ActiveBoth IRQs.
-	 *
-	 * According to the Microsoft GPIO documentation, triggering GPIO
-	 * interrupts marked as ActiveBoth during initialization is correct
-	 * as long as the associated GPIO line is already "asserted"
-	 * (logic level low). We should not trigger edge-based GPIO
-	 * interrupts not marked as ActiveBoth.
-	 *
-	 * See: https://learn.microsoft.com/en-us/windows-hardware/drivers/bringup/general-purpose-i-o--gpio-
-	 * Section: "GPIO controllers and ActiveBoth interrupts"
-	 */
-	if (acpi_gpio_need_run_edge_events_on_boot() &&
-	    ((event->irqflags & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)) ==
-	     (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING))) {
-		value = gpiod_get_raw_value_cansleep(event->desc);
-		if (value == 0)
-			event->handler(event->irq, event);
-	}
-}
-
-static void acpi_gpiochip_request_irqs(struct acpi_gpio_chip *acpi_gpio)
-{
-	struct acpi_gpio_event *event;
-
-	list_for_each_entry(event, &acpi_gpio->events, node)
-		acpi_gpiochip_request_irq(acpi_gpio, event);
-}
 
 static enum gpiod_flags
 acpi_gpio_to_gpiod_flags(const struct acpi_resource_gpio *agpio, int polarity)
@@ -296,229 +233,9 @@ struct gpio_desc *acpi_request_own_gpiod(struct gpio_chip *chip,
 	return desc;
 }
 
-static bool acpi_gpio_irq_is_wake(struct device *parent,
-				  const struct acpi_resource_gpio *agpio)
-{
-	unsigned int pin;
-
-	if (agpio->pin_table_length == 0)
-		return false;
 
-	pin = agpio->pin_table[0];
 
-	if (agpio->wake_capable != ACPI_WAKE_CAPABLE)
-		return false;
-
-	if (acpi_gpio_in_ignore_list(ACPI_GPIO_IGNORE_WAKE, dev_name(parent), pin)) {
-		dev_info(parent, "Ignoring wakeup on pin %u\n", pin);
-		return false;
-	}
 
-	return true;
-}
-
-/* Always returns AE_OK so that we keep looping over the resources */
-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;
-	unsigned int pin;
-	int ret, irq;
-
-	if (!acpi_gpio_get_irq_resource(ares, &agpio))
-		return AE_OK;
-
-	if (agpio->pin_table_length == 0)
-		return AE_OK;
-
-	handle = ACPI_HANDLE(chip->parent);
-	pin = agpio->pin_table[0];
-
-	if (pin <= 255) {
-		char ev_name[8];
-
-		snprintf(ev_name, sizeof(ev_name), "_%c%02X",
-			 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;
-
-	if (acpi_gpio_in_ignore_list(ACPI_GPIO_IGNORE_INTERRUPT, dev_name(chip->parent), pin)) {
-		dev_info(chip->parent, "Ignoring interrupt on pin %u\n", pin);
-		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 %pe\n",
-			pin, 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_obj(*event);
-	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;
-}
-
-/**
- * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
- * @chip:      GPIO chip
- *
- * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
- * handled by ACPI event methods which need to be called from the GPIO
- * chip's interrupt handler. acpi_gpiochip_request_interrupts() finds out which
- * GPIO pins have ACPI event methods and assigns interrupt handlers that calls
- * the ACPI event methods for those pins.
- */
-void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
-{
-	struct acpi_gpio_chip *acpi_gpio;
-	acpi_handle handle;
-	acpi_status status;
-
-	if (!chip->parent || !chip->to_irq)
-		return;
-
-	handle = ACPI_HANDLE(chip->parent);
-	if (!handle)
-		return;
-
-	status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
-	if (ACPI_FAILURE(status))
-		return;
-
-	if (acpi_quirk_skip_gpio_event_handlers())
-		return;
-
-	acpi_walk_resources(handle, METHOD_NAME__AEI,
-			    acpi_gpiochip_alloc_event, acpi_gpio);
-
-	if (acpi_gpio_add_to_deferred_list(&acpi_gpio->deferred_req_irqs_list_entry))
-		return;
-
-	acpi_gpiochip_request_irqs(acpi_gpio);
-}
-EXPORT_SYMBOL_GPL(acpi_gpiochip_request_interrupts);
-
-/**
- * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
- * @chip:      GPIO chip
- *
- * Free interrupts associated with GPIO ACPI event method for the given
- * GPIO chip.
- */
-void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
-{
-	struct acpi_gpio_chip *acpi_gpio;
-	struct acpi_gpio_event *event, *ep;
-	acpi_handle handle;
-	acpi_status status;
-
-	if (!chip->parent || !chip->to_irq)
-		return;
-
-	handle = ACPI_HANDLE(chip->parent);
-	if (!handle)
-		return;
-
-	status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
-	if (ACPI_FAILURE(status))
-		return;
-
-	acpi_gpio_remove_from_deferred_list(&acpi_gpio->deferred_req_irqs_list_entry);
-
-	list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
-		if (event->irq_requested) {
-			if (event->irq_is_wake)
-				disable_irq_wake(event->irq);
-
-			free_irq(event->irq, event);
-		}
-
-		gpiochip_unlock_as_irq(chip, event->pin);
-		gpiochip_free_own_desc(event->desc);
-		list_del(&event->node);
-		kfree(event);
-	}
-}
-EXPORT_SYMBOL_GPL(acpi_gpiochip_free_interrupts);
-
-void __init acpi_gpio_process_deferred_list(struct list_head *list)
-{
-	struct acpi_gpio_chip *acpi_gpio, *tmp;
-
-	list_for_each_entry_safe(acpi_gpio, tmp, list, deferred_req_irqs_list_entry)
-		acpi_gpiochip_request_irqs(acpi_gpio);
-}
 
 int acpi_dev_add_driver_gpios(struct acpi_device *adev,
 			      const struct acpi_gpio_mapping *gpios)
-- 
2.54.0