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-rw-r--r--drivers/acpi/evged.c196
1 files changed, 196 insertions, 0 deletions
diff --git a/drivers/acpi/evged.c b/drivers/acpi/evged.c
new file mode 100644
index 000000000..fe6b6792c
--- /dev/null
+++ b/drivers/acpi/evged.c
@@ -0,0 +1,196 @@
+// 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 int ged_remove(struct platform_device *pdev)
+{
+ ged_shutdown(pdev);
+ return 0;
+}
+
+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);