1 files changed, 123 insertions, 0 deletions

diff --git a/drivers/acpi/acpi_watchdog.c b/drivers/acpi/acpi_watchdog.c
new file mode 100644
index 000000000000..13caebd679f5
--- /dev/null
+++ b/drivers/acpi/acpi_watchdog.c
@@ -0,0 +1,123 @@
+/*
+ * ACPI watchdog table parsing support.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) "ACPI: watchdog: " fmt
+
+#include <linux/acpi.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+
+#include "internal.h"
+
+/**
+ * Returns true if this system should prefer ACPI based watchdog instead of
+ * the native one (which are typically the same hardware).
+ */
+bool acpi_has_watchdog(void)
+{
+        struct acpi_table_header hdr;
+
+        if (acpi_disabled)
+                return false;
+
+        return ACPI_SUCCESS(acpi_get_table_header(ACPI_SIG_WDAT, 0, &hdr));
+}
+EXPORT_SYMBOL_GPL(acpi_has_watchdog);
+
+void __init acpi_watchdog_init(void)
+{
+        const struct acpi_wdat_entry *entries;
+        const struct acpi_table_wdat *wdat;
+        struct list_head resource_list;
+        struct resource_entry *rentry;
+        struct platform_device *pdev;
+        struct resource *resources;
+        size_t nresources = 0;
+        acpi_status status;
+        int i;
+
+        status = acpi_get_table(ACPI_SIG_WDAT, 0,
+                                (struct acpi_table_header **)&wdat);
+        if (ACPI_FAILURE(status)) {
+                /* It is fine if there is no WDAT */
+                return;
+        }
+
+        /* Watchdog disabled by BIOS */
+        if (!(wdat->flags & ACPI_WDAT_ENABLED))
+                return;
+
+        /* Skip legacy PCI WDT devices */
+        if (wdat->pci_segment != 0xff || wdat->pci_bus != 0xff ||
+            wdat->pci_device != 0xff || wdat->pci_function != 0xff)
+                return;
+
+        INIT_LIST_HEAD(&resource_list);
+
+        entries = (struct acpi_wdat_entry *)(wdat + 1);
+        for (i = 0; i < wdat->entries; i++) {
+                const struct acpi_generic_address *gas;
+                struct resource_entry *rentry;
+                struct resource res;
+                bool found;
+
+                gas = &entries[i].register_region;
+
+                res.start = gas->address;
+                if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+                        res.flags = IORESOURCE_MEM;
+                        res.end = res.start + ALIGN(gas->access_width, 4);
+                } else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
+                        res.flags = IORESOURCE_IO;
+                        res.end = res.start + gas->access_width;
+                } else {
+                        pr_warn("Unsupported address space: %u\n",
+                                gas->space_id);
+                        goto fail_free_resource_list;
+                }
+
+                found = false;
+                resource_list_for_each_entry(rentry, &resource_list) {
+                        if (resource_contains(rentry->res, &res)) {
+                                found = true;
+                                break;
+                        }
+                }
+
+                if (!found) {
+                        rentry = resource_list_create_entry(NULL, 0);
+                        if (!rentry)
+                                goto fail_free_resource_list;
+
+                        *rentry->res = res;
+                        resource_list_add_tail(rentry, &resource_list);
+                        nresources++;
+                }
+        }
+
+        resources = kcalloc(nresources, sizeof(*resources), GFP_KERNEL);
+        if (!resources)
+                goto fail_free_resource_list;
+
+        i = 0;
+        resource_list_for_each_entry(rentry, &resource_list)
+                resources[i++] = *rentry->res;
+
+        pdev = platform_device_register_simple("wdat_wdt", PLATFORM_DEVID_NONE,
+                                               resources, nresources);
+        if (IS_ERR(pdev))
+                pr_err("Failed to create platform device\n");
+
+        kfree(resources);
+
+fail_free_resource_list:
+        resource_list_free(&resource_list);
+}