// SPDX-License-Identifier: GPL-2.0-only/* * Generic Event Device for ACPI. * * Copyright (c) 2016, The Linux Foundation. All rights reserved. * * Generic Event Device allows platforms to handle interrupts in ACPI * ASL statements. It follows very similar to  _EVT method approach * from GPIO events. All interrupts are listed in _CRS and the handler * is written in _EVT method. Here is an example. * * Device (GED0) * { * *     Name (_HID, "ACPI0013") *     Name (_UID, 0) *     Method (_CRS, 0x0, Serialized) *     { *		Name (RBUF, ResourceTemplate () *		{ *		Interrupt(ResourceConsumer, Edge, ActiveHigh, Shared, , , ) *		{123} *		} *     }) * *     Method (_EVT, 1) { *             if (Lequal(123, Arg0)) *             { *             } *     } * } */ #include <linux/err.h>#include <linux/init.h>#include <linux/interrupt.h>#include <linux/list.h>#include <linux/platform_device.h>#include <linux/acpi.h> #define MODULE_NAME	"acpi-ged" 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);		return AE_ERROR;	} 	dev_dbg(dev, "GED listening GSI %u @ IRQ %u\n", gsi, irq);	list_add_tail(&event->node, &geddev->event_list);	return AE_OK;} static int ged_probe(struct platform_device *pdev){	struct acpi_ged_device *geddev;	acpi_status acpi_ret; 	geddev = devm_kzalloc(&pdev->dev, sizeof(*geddev), GFP_KERNEL);	if (!geddev)		return -ENOMEM; 	geddev->dev = &pdev->dev;	INIT_LIST_HEAD(&geddev->event_list);	acpi_ret = acpi_walk_resources(ACPI_HANDLE(&pdev->dev), "_CRS",				       acpi_ged_request_interrupt, geddev);	if (ACPI_FAILURE(acpi_ret)) {		dev_err(&pdev->dev, "unable to parse the _CRS record\n");		return -EINVAL;	}	platform_set_drvdata(pdev, geddev); 	return 0;} static void ged_shutdown(struct platform_device *pdev){	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) {		free_irq(event->irq, event);		list_del(&event->node);		dev_dbg(geddev->dev, "GED releasing GSI %u @ IRQ %u\n",			 event->gsi, event->irq);	}} static void ged_remove(struct platform_device *pdev){	ged_shutdown(pdev);} static const struct acpi_device_id ged_acpi_ids[] = {	{"ACPI0013"},	{},}; static struct platform_driver ged_driver = {	.probe = ged_probe,	.remove = ged_remove,	.shutdown = ged_shutdown,	.driver = {		.name = MODULE_NAME,		.acpi_match_table = ACPI_PTR(ged_acpi_ids),	},};builtin_platform_driver(ged_driver);