// 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_new = ged_remove, .shutdown = ged_shutdown, .driver = { .name = MODULE_NAME, .acpi_match_table = ACPI_PTR(ged_acpi_ids), }, }; builtin_platform_driver(ged_driver);