[PATCH] ACPI: GED: Support GpioInt event resources

[Rahul Pon <theflyingrahul@gmail.com>]

The Generic Event Device accepts only Interrupt and ExtendedInterrupt
resources in _CRS. Some ACPI firmware signals GED events through GPIO
controllers instead: the HP OmniBook 5 16-bf1xxx (Snapdragon X2) describes
its lid (LIGE) and embedded-controller event device (ECGE) as ACPI0013 with
GpioInt resources, and both currently fail to probe with "unable to parse
IRQ resource".

Handle GpioInt resources: get the Linux IRQ with acpi_dev_gpio_irq_get(),
which applies the trigger and polarity and returns -EPROBE_DEFER until the
GPIO controller is registered, and evaluate _EVT with the GPIO pin number,
as done for GSIs above 255. GpioIo resources are skipped. On a failed walk,
free the events already requested and propagate the GPIO error (including
-EPROBE_DEFER) instead of -EINVAL.

Tested on the HP OmniBook 5 16-bf1xxx: lid close/open run _EVT and reach
the ACPI button driver and logind.

Assisted-by: LLM
Signed-off-by: Rahul Pon <theflyingrahul@gmail.com>
---
 drivers/acpi/evged.c | 46 +++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 43 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/evged.c b/drivers/acpi/evged.c
index 5c35cbc7f6..478172ede7 100644
--- a/drivers/acpi/evged.c
+++ b/drivers/acpi/evged.c
@@ -43,6 +43,8 @@
 struct acpi_ged_device {
 	struct device *dev;
 	struct list_head event_list;
+	unsigned int gpio_index;
+	int error;
 };
 
 struct acpi_ged_event {
@@ -76,7 +78,7 @@ static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,
 	struct device *dev = geddev->dev;
 	acpi_handle handle = ACPI_HANDLE(dev);
 	acpi_handle evt_handle;
-	struct resource r;
+	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];
@@ -85,6 +87,33 @@ static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,
 	if (ares->type == ACPI_RESOURCE_TYPE_END_TAG)
 		return AE_OK;
 
+	if (ares->type == ACPI_RESOURCE_TYPE_GPIO) {
+		struct acpi_resource_gpio *agpio;
+		int ret;
+
+		/* GpioIo resources are not event sources. */
+		if (!acpi_gpio_get_irq_resource(ares, &agpio))
+			return AE_OK;
+
+		/* The GPIO core applies the GpioInt trigger and polarity. */
+		ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), geddev->gpio_index++);
+		if (ret < 0) {
+			geddev->error = ret;
+			return AE_ERROR;
+		}
+		irq = ret;
+		gsi = agpio->pin_table[0];
+		if (agpio->shareable == ACPI_SHARED)
+			r.flags |= IORESOURCE_IRQ_SHAREABLE;
+
+		/* As for GSIs above 255, GPIO-signaled events use _EVT. */
+		if (ACPI_FAILURE(acpi_get_handle(handle, "_EVT", &evt_handle))) {
+			dev_err(dev, "cannot locate _EVT method\n");
+			return AE_ERROR;
+		}
+		goto request;
+	}
+
 	if (!acpi_dev_resource_interrupt(ares, 0, &r)) {
 		dev_err(dev, "unable to parse IRQ resource\n");
 		return AE_ERROR;
@@ -115,6 +144,7 @@ static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,
 		return AE_ERROR;
 	}
 
+request:
 	event = devm_kzalloc(dev, sizeof(*event), GFP_KERNEL);
 	if (!event)
 		return AE_ERROR;
@@ -138,6 +168,8 @@ static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,
 	return AE_OK;
 }
 
+static void acpi_ged_free_events(struct acpi_ged_device *geddev);
+
 static int ged_probe(struct platform_device *pdev)
 {
 	struct acpi_ged_device *geddev;
@@ -152,6 +184,10 @@ static int ged_probe(struct platform_device *pdev)
 	acpi_ret = acpi_walk_resources(ACPI_HANDLE(&pdev->dev), "_CRS",
 				       acpi_ged_request_interrupt, geddev);
 	if (ACPI_FAILURE(acpi_ret)) {
+		acpi_ged_free_events(geddev);
+		if (geddev->error)
+			return dev_err_probe(&pdev->dev, geddev->error,
+					     "unable to get GPIO event IRQ\n");
 		dev_err(&pdev->dev, "unable to parse the _CRS record\n");
 		return -EINVAL;
 	}
@@ -160,9 +196,8 @@ static int ged_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static void ged_shutdown(struct platform_device *pdev)
+static void acpi_ged_free_events(struct acpi_ged_device *geddev)
 {
-	struct acpi_ged_device *geddev = platform_get_drvdata(pdev);
 	struct acpi_ged_event *event, *next;
 
 	list_for_each_entry_safe(event, next, &geddev->event_list, node) {
@@ -173,6 +208,11 @@ static void ged_shutdown(struct platform_device *pdev)
 	}
 }
 
+static void ged_shutdown(struct platform_device *pdev)
+{
+	acpi_ged_free_events(platform_get_drvdata(pdev));
+}
+
 static void ged_remove(struct platform_device *pdev)
 {
 	ged_shutdown(pdev);

base-commit: 551c722f40809618230001baccf219193e22fc5a
-- 
2.53.0