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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Generic Event Device for ACPI.4 *5 * Copyright (c) 2016, The Linux Foundation. All rights reserved.6 *7 * Generic Event Device allows platforms to handle interrupts in ACPI8 * ASL statements. It follows very similar to _EVT method approach9 * from GPIO events. All interrupts are listed in _CRS and the handler10 * is written in _EVT method. Here is an example.11 *12 * Device (GED0)13 * {14 *15 * Name (_HID, "ACPI0013")16 * Name (_UID, 0)17 * Method (_CRS, 0x0, Serialized)18 * {19 * Name (RBUF, ResourceTemplate ()20 * {21 * Interrupt(ResourceConsumer, Edge, ActiveHigh, Shared, , , )22 * {123}23 * }24 * })25 *26 * Method (_EVT, 1) {27 * if (Lequal(123, Arg0))28 * {29 * }30 * }31 * }32 */33 34#include <linux/err.h>35#include <linux/init.h>36#include <linux/interrupt.h>37#include <linux/list.h>38#include <linux/platform_device.h>39#include <linux/acpi.h>40 41#define MODULE_NAME "acpi-ged"42 43struct acpi_ged_device {44 struct device *dev;45 struct list_head event_list;46};47 48struct acpi_ged_event {49 struct list_head node;50 struct device *dev;51 unsigned int gsi;52 unsigned int irq;53 acpi_handle handle;54};55 56static irqreturn_t acpi_ged_irq_handler(int irq, void *data)57{58 struct acpi_ged_event *event = data;59 acpi_status acpi_ret;60 61 acpi_ret = acpi_execute_simple_method(event->handle, NULL, event->gsi);62 if (ACPI_FAILURE(acpi_ret))63 dev_err_once(event->dev, "IRQ method execution failed\n");64 65 return IRQ_HANDLED;66}67 68static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,69 void *context)70{71 struct acpi_ged_event *event;72 unsigned int irq;73 unsigned int gsi;74 unsigned int irqflags = IRQF_ONESHOT;75 struct acpi_ged_device *geddev = context;76 struct device *dev = geddev->dev;77 acpi_handle handle = ACPI_HANDLE(dev);78 acpi_handle evt_handle;79 struct resource r;80 struct acpi_resource_irq *p = &ares->data.irq;81 struct acpi_resource_extended_irq *pext = &ares->data.extended_irq;82 char ev_name[5];83 u8 trigger;84 85 if (ares->type == ACPI_RESOURCE_TYPE_END_TAG)86 return AE_OK;87 88 if (!acpi_dev_resource_interrupt(ares, 0, &r)) {89 dev_err(dev, "unable to parse IRQ resource\n");90 return AE_ERROR;91 }92 if (ares->type == ACPI_RESOURCE_TYPE_IRQ) {93 gsi = p->interrupts[0];94 trigger = p->triggering;95 } else {96 gsi = pext->interrupts[0];97 trigger = pext->triggering;98 }99 100 irq = r.start;101 102 switch (gsi) {103 case 0 ... 255:104 sprintf(ev_name, "_%c%02X",105 trigger == ACPI_EDGE_SENSITIVE ? 'E' : 'L', gsi);106 107 if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))108 break;109 fallthrough;110 default:111 if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))112 break;113 114 dev_err(dev, "cannot locate _EVT method\n");115 return AE_ERROR;116 }117 118 event = devm_kzalloc(dev, sizeof(*event), GFP_KERNEL);119 if (!event)120 return AE_ERROR;121 122 event->gsi = gsi;123 event->dev = dev;124 event->irq = irq;125 event->handle = evt_handle;126 127 if (r.flags & IORESOURCE_IRQ_SHAREABLE)128 irqflags |= IRQF_SHARED;129 130 if (request_threaded_irq(irq, NULL, acpi_ged_irq_handler,131 irqflags, "ACPI:Ged", event)) {132 dev_err(dev, "failed to setup event handler for irq %u\n", irq);133 return AE_ERROR;134 }135 136 dev_dbg(dev, "GED listening GSI %u @ IRQ %u\n", gsi, irq);137 list_add_tail(&event->node, &geddev->event_list);138 return AE_OK;139}140 141static int ged_probe(struct platform_device *pdev)142{143 struct acpi_ged_device *geddev;144 acpi_status acpi_ret;145 146 geddev = devm_kzalloc(&pdev->dev, sizeof(*geddev), GFP_KERNEL);147 if (!geddev)148 return -ENOMEM;149 150 geddev->dev = &pdev->dev;151 INIT_LIST_HEAD(&geddev->event_list);152 acpi_ret = acpi_walk_resources(ACPI_HANDLE(&pdev->dev), "_CRS",153 acpi_ged_request_interrupt, geddev);154 if (ACPI_FAILURE(acpi_ret)) {155 dev_err(&pdev->dev, "unable to parse the _CRS record\n");156 return -EINVAL;157 }158 platform_set_drvdata(pdev, geddev);159 160 return 0;161}162 163static void ged_shutdown(struct platform_device *pdev)164{165 struct acpi_ged_device *geddev = platform_get_drvdata(pdev);166 struct acpi_ged_event *event, *next;167 168 list_for_each_entry_safe(event, next, &geddev->event_list, node) {169 free_irq(event->irq, event);170 list_del(&event->node);171 dev_dbg(geddev->dev, "GED releasing GSI %u @ IRQ %u\n",172 event->gsi, event->irq);173 }174}175 176static void ged_remove(struct platform_device *pdev)177{178 ged_shutdown(pdev);179}180 181static const struct acpi_device_id ged_acpi_ids[] = {182 {"ACPI0013"},183 {},184};185 186static struct platform_driver ged_driver = {187 .probe = ged_probe,188 .remove_new = ged_remove,189 .shutdown = ged_shutdown,190 .driver = {191 .name = MODULE_NAME,192 .acpi_match_table = ACPI_PTR(ged_acpi_ids),193 },194};195builtin_platform_driver(ged_driver);196