155 lines
3.8 KiB
C
155 lines
3.8 KiB
C
/*
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* Generic Event Device for ACPI.
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*
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* Copyright (c) 2016, The Linux Foundation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* Generic Event Device allows platforms to handle interrupts in ACPI
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* ASL statements. It follows very similar to _EVT method approach
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* from GPIO events. All interrupts are listed in _CRS and the handler
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* is written in _EVT method. Here is an example.
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*
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* Device (GED0)
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* {
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*
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* Name (_HID, "ACPI0013")
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* Name (_UID, 0)
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* Method (_CRS, 0x0, Serialized)
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* {
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* Name (RBUF, ResourceTemplate ()
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* {
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* Interrupt(ResourceConsumer, Edge, ActiveHigh, Shared, , , )
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* {123}
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* }
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* })
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*
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* Method (_EVT, 1) {
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* if (Lequal(123, Arg0))
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* {
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* }
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* }
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* }
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*
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*/
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/list.h>
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#include <linux/platform_device.h>
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#include <linux/acpi.h>
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#define MODULE_NAME "acpi-ged"
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struct acpi_ged_event {
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struct list_head node;
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struct device *dev;
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unsigned int gsi;
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unsigned int irq;
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acpi_handle handle;
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};
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static irqreturn_t acpi_ged_irq_handler(int irq, void *data)
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{
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struct acpi_ged_event *event = data;
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acpi_status acpi_ret;
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acpi_ret = acpi_execute_simple_method(event->handle, NULL, event->gsi);
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if (ACPI_FAILURE(acpi_ret))
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dev_err_once(event->dev, "IRQ method execution failed\n");
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return IRQ_HANDLED;
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}
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static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,
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void *context)
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{
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struct acpi_ged_event *event;
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unsigned int irq;
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unsigned int gsi;
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unsigned int irqflags = IRQF_ONESHOT;
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struct device *dev = context;
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acpi_handle handle = ACPI_HANDLE(dev);
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acpi_handle evt_handle;
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struct resource r;
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struct acpi_resource_irq *p = &ares->data.irq;
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struct acpi_resource_extended_irq *pext = &ares->data.extended_irq;
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if (ares->type == ACPI_RESOURCE_TYPE_END_TAG)
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return AE_OK;
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if (!acpi_dev_resource_interrupt(ares, 0, &r)) {
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dev_err(dev, "unable to parse IRQ resource\n");
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return AE_ERROR;
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}
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if (ares->type == ACPI_RESOURCE_TYPE_IRQ)
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gsi = p->interrupts[0];
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else
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gsi = pext->interrupts[0];
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irq = r.start;
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if (ACPI_FAILURE(acpi_get_handle(handle, "_EVT", &evt_handle))) {
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dev_err(dev, "cannot locate _EVT method\n");
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return AE_ERROR;
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}
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dev_info(dev, "GED listening GSI %u @ IRQ %u\n", gsi, irq);
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event = devm_kzalloc(dev, sizeof(*event), GFP_KERNEL);
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if (!event)
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return AE_ERROR;
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event->gsi = gsi;
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event->dev = dev;
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event->irq = irq;
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event->handle = evt_handle;
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if (r.flags & IORESOURCE_IRQ_SHAREABLE)
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irqflags |= IRQF_SHARED;
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if (devm_request_threaded_irq(dev, irq, NULL, acpi_ged_irq_handler,
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irqflags, "ACPI:Ged", event)) {
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dev_err(dev, "failed to setup event handler for irq %u\n", irq);
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return AE_ERROR;
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}
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return AE_OK;
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}
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static int ged_probe(struct platform_device *pdev)
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{
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acpi_status acpi_ret;
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acpi_ret = acpi_walk_resources(ACPI_HANDLE(&pdev->dev), "_CRS",
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acpi_ged_request_interrupt, &pdev->dev);
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if (ACPI_FAILURE(acpi_ret)) {
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dev_err(&pdev->dev, "unable to parse the _CRS record\n");
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return -EINVAL;
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}
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return 0;
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}
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static const struct acpi_device_id ged_acpi_ids[] = {
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{"ACPI0013"},
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{},
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};
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static struct platform_driver ged_driver = {
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.probe = ged_probe,
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.driver = {
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.name = MODULE_NAME,
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.acpi_match_table = ACPI_PTR(ged_acpi_ids),
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},
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};
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builtin_platform_driver(ged_driver);
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