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196 lines
4.6 KiB
196 lines
4.6 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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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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* 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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#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_device { |
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struct device *dev; |
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struct list_head event_list; |
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}; |
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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 acpi_ged_device *geddev = context; |
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struct device *dev = geddev->dev; |
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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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char ev_name[5]; |
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u8 trigger; |
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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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trigger = p->triggering; |
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} else { |
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gsi = pext->interrupts[0]; |
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trigger = pext->triggering; |
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} |
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irq = r.start; |
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switch (gsi) { |
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case 0 ... 255: |
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sprintf(ev_name, "_%c%02X", |
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trigger == ACPI_EDGE_SENSITIVE ? 'E' : 'L', gsi); |
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if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle))) |
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break; |
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fallthrough; |
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default: |
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if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle))) |
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break; |
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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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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 (request_threaded_irq(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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dev_dbg(dev, "GED listening GSI %u @ IRQ %u\n", gsi, irq); |
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list_add_tail(&event->node, &geddev->event_list); |
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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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struct acpi_ged_device *geddev; |
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acpi_status acpi_ret; |
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geddev = devm_kzalloc(&pdev->dev, sizeof(*geddev), GFP_KERNEL); |
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if (!geddev) |
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return -ENOMEM; |
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geddev->dev = &pdev->dev; |
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INIT_LIST_HEAD(&geddev->event_list); |
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acpi_ret = acpi_walk_resources(ACPI_HANDLE(&pdev->dev), "_CRS", |
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acpi_ged_request_interrupt, geddev); |
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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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platform_set_drvdata(pdev, geddev); |
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return 0; |
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} |
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static void ged_shutdown(struct platform_device *pdev) |
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{ |
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struct acpi_ged_device *geddev = platform_get_drvdata(pdev); |
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struct acpi_ged_event *event, *next; |
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list_for_each_entry_safe(event, next, &geddev->event_list, node) { |
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free_irq(event->irq, event); |
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list_del(&event->node); |
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dev_dbg(geddev->dev, "GED releasing GSI %u @ IRQ %u\n", |
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event->gsi, event->irq); |
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} |
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} |
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static int ged_remove(struct platform_device *pdev) |
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{ |
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ged_shutdown(pdev); |
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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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.remove = ged_remove, |
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.shutdown = ged_shutdown, |
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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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