Initial import

1 files changed, 969 insertions, 0 deletions

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
new file mode 100644
index 000000000..aac47573f
--- /dev/null
+++ b/drivers/platform/x86/wmi.c
@@ -0,0 +1,969 @@
+/*
+ *  ACPI-WMI mapping driver
+ *
+ *  Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
+ *
+ *  GUID parsing code from ldm.c is:
+ *   Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
+ *   Copyright (c) 2001-2007 Anton Altaparmakov
+ *   Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/acpi.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+ACPI_MODULE_NAME("wmi");
+MODULE_AUTHOR("Carlos Corbacho");
+MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
+MODULE_LICENSE("GPL");
+
+#define ACPI_WMI_CLASS "wmi"
+
+static LIST_HEAD(wmi_block_list);
+
+struct guid_block {
+	char guid[16];
+	union {
+		char object_id[2];
+		struct {
+			unsigned char notify_id;
+			unsigned char reserved;
+		};
+	};
+	u8 instance_count;
+	u8 flags;
+};
+
+struct wmi_block {
+	struct list_head list;
+	struct guid_block gblock;
+	acpi_handle handle;
+	wmi_notify_handler handler;
+	void *handler_data;
+	struct device dev;
+};
+
+
+/*
+ * If the GUID data block is marked as expensive, we must enable and
+ * explicitily disable data collection.
+ */
+#define ACPI_WMI_EXPENSIVE   0x1
+#define ACPI_WMI_METHOD      0x2	/* GUID is a method */
+#define ACPI_WMI_STRING      0x4	/* GUID takes & returns a string */
+#define ACPI_WMI_EVENT       0x8	/* GUID is an event */
+
+static bool debug_event;
+module_param(debug_event, bool, 0444);
+MODULE_PARM_DESC(debug_event,
+		 "Log WMI Events [0/1]");
+
+static bool debug_dump_wdg;
+module_param(debug_dump_wdg, bool, 0444);
+MODULE_PARM_DESC(debug_dump_wdg,
+		 "Dump available WMI interfaces [0/1]");
+
+static int acpi_wmi_remove(struct acpi_device *device);
+static int acpi_wmi_add(struct acpi_device *device);
+static void acpi_wmi_notify(struct acpi_device *device, u32 event);
+
+static const struct acpi_device_id wmi_device_ids[] = {
+	{"PNP0C14", 0},
+	{"pnp0c14", 0},
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
+
+static struct acpi_driver acpi_wmi_driver = {
+	.name = "wmi",
+	.class = ACPI_WMI_CLASS,
+	.ids = wmi_device_ids,
+	.ops = {
+		.add = acpi_wmi_add,
+		.remove = acpi_wmi_remove,
+		.notify = acpi_wmi_notify,
+	},
+};
+
+/*
+ * GUID parsing functions
+ */
+
+/**
+ * wmi_parse_hexbyte - Convert a ASCII hex number to a byte
+ * @src:  Pointer to at least 2 characters to convert.
+ *
+ * Convert a two character ASCII hex string to a number.
+ *
+ * Return:  0-255  Success, the byte was parsed correctly
+ *          -1     Error, an invalid character was supplied
+ */
+static int wmi_parse_hexbyte(const u8 *src)
+{
+	int h;
+	int value;
+
+	/* high part */
+	h = value = hex_to_bin(src[0]);
+	if (value < 0)
+		return -1;
+
+	/* low part */
+	value = hex_to_bin(src[1]);
+	if (value >= 0)
+		return (h << 4) | value;
+	return -1;
+}
+
+/**
+ * wmi_swap_bytes - Rearrange GUID bytes to match GUID binary
+ * @src:   Memory block holding binary GUID (16 bytes)
+ * @dest:  Memory block to hold byte swapped binary GUID (16 bytes)
+ *
+ * Byte swap a binary GUID to match it's real GUID value
+ */
+static void wmi_swap_bytes(u8 *src, u8 *dest)
+{
+	int i;
+
+	for (i = 0; i <= 3; i++)
+		memcpy(dest + i, src + (3 - i), 1);
+
+	for (i = 0; i <= 1; i++)
+		memcpy(dest + 4 + i, src + (5 - i), 1);
+
+	for (i = 0; i <= 1; i++)
+		memcpy(dest + 6 + i, src + (7 - i), 1);
+
+	memcpy(dest + 8, src + 8, 8);
+}
+
+/**
+ * wmi_parse_guid - Convert GUID from ASCII to binary
+ * @src:   36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ * @dest:  Memory block to hold binary GUID (16 bytes)
+ *
+ * N.B. The GUID need not be NULL terminated.
+ *
+ * Return:  'true'   @dest contains binary GUID
+ *          'false'  @dest contents are undefined
+ */
+static bool wmi_parse_guid(const u8 *src, u8 *dest)
+{
+	static const int size[] = { 4, 2, 2, 2, 6 };
+	int i, j, v;
+
+	if (src[8]  != '-' || src[13] != '-' ||
+		src[18] != '-' || src[23] != '-')
+		return false;
+
+	for (j = 0; j < 5; j++, src++) {
+		for (i = 0; i < size[j]; i++, src += 2, *dest++ = v) {
+			v = wmi_parse_hexbyte(src);
+			if (v < 0)
+				return false;
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Convert a raw GUID to the ACII string representation
+ */
+static int wmi_gtoa(const char *in, char *out)
+{
+	int i;
+
+	for (i = 3; i >= 0; i--)
+		out += sprintf(out, "%02X", in[i] & 0xFF);
+
+	out += sprintf(out, "-");
+	out += sprintf(out, "%02X", in[5] & 0xFF);
+	out += sprintf(out, "%02X", in[4] & 0xFF);
+	out += sprintf(out, "-");
+	out += sprintf(out, "%02X", in[7] & 0xFF);
+	out += sprintf(out, "%02X", in[6] & 0xFF);
+	out += sprintf(out, "-");
+	out += sprintf(out, "%02X", in[8] & 0xFF);
+	out += sprintf(out, "%02X", in[9] & 0xFF);
+	out += sprintf(out, "-");
+
+	for (i = 10; i <= 15; i++)
+		out += sprintf(out, "%02X", in[i] & 0xFF);
+
+	*out = '\0';
+	return 0;
+}
+
+static bool find_guid(const char *guid_string, struct wmi_block **out)
+{
+	char tmp[16], guid_input[16];
+	struct wmi_block *wblock;
+	struct guid_block *block;
+	struct list_head *p;
+
+	wmi_parse_guid(guid_string, tmp);
+	wmi_swap_bytes(tmp, guid_input);
+
+	list_for_each(p, &wmi_block_list) {
+		wblock = list_entry(p, struct wmi_block, list);
+		block = &wblock->gblock;
+
+		if (memcmp(block->guid, guid_input, 16) == 0) {
+			if (out)
+				*out = wblock;
+			return true;
+		}
+	}
+	return false;
+}
+
+static acpi_status wmi_method_enable(struct wmi_block *wblock, int enable)
+{
+	struct guid_block *block = NULL;
+	char method[5];
+	acpi_status status;
+	acpi_handle handle;
+
+	block = &wblock->gblock;
+	handle = wblock->handle;
+
+	snprintf(method, 5, "WE%02X", block->notify_id);
+	status = acpi_execute_simple_method(handle, method, enable);
+
+	if (status != AE_OK && status != AE_NOT_FOUND)
+		return status;
+	else
+		return AE_OK;
+}
+
+/*
+ * Exported WMI functions
+ */
+/**
+ * wmi_evaluate_method - Evaluate a WMI method
+ * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ * @instance: Instance index
+ * @method_id: Method ID to call
+ * &in: Buffer containing input for the method call
+ * &out: Empty buffer to return the method results
+ *
+ * Call an ACPI-WMI method
+ */
+acpi_status wmi_evaluate_method(const char *guid_string, u8 instance,
+u32 method_id, const struct acpi_buffer *in, struct acpi_buffer *out)
+{
+	struct guid_block *block = NULL;
+	struct wmi_block *wblock = NULL;
+	acpi_handle handle;
+	acpi_status status;
+	struct acpi_object_list input;
+	union acpi_object params[3];
+	char method[5] = "WM";
+
+	if (!find_guid(guid_string, &wblock))
+		return AE_ERROR;
+
+	block = &wblock->gblock;
+	handle = wblock->handle;
+
+	if (!(block->flags & ACPI_WMI_METHOD))
+		return AE_BAD_DATA;
+
+	if (block->instance_count < instance)
+		return AE_BAD_PARAMETER;
+
+	input.count = 2;
+	input.pointer = params;
+	params[0].type = ACPI_TYPE_INTEGER;
+	params[0].integer.value = instance;
+	params[1].type = ACPI_TYPE_INTEGER;
+	params[1].integer.value = method_id;
+
+	if (in) {
+		input.count = 3;
+
+		if (block->flags & ACPI_WMI_STRING) {
+			params[2].type = ACPI_TYPE_STRING;
+		} else {
+			params[2].type = ACPI_TYPE_BUFFER;
+		}
+		params[2].buffer.length = in->length;
+		params[2].buffer.pointer = in->pointer;
+	}
+
+	strncat(method, block->object_id, 2);
+
+	status = acpi_evaluate_object(handle, method, &input, out);
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(wmi_evaluate_method);
+
+/**
+ * wmi_query_block - Return contents of a WMI block
+ * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ * @instance: Instance index
+ * &out: Empty buffer to return the contents of the data block to
+ *
+ * Return the contents of an ACPI-WMI data block to a buffer
+ */
+acpi_status wmi_query_block(const char *guid_string, u8 instance,
+struct acpi_buffer *out)
+{
+	struct guid_block *block = NULL;
+	struct wmi_block *wblock = NULL;
+	acpi_handle handle;
+	acpi_status status, wc_status = AE_ERROR;
+	struct acpi_object_list input;
+	union acpi_object wq_params[1];
+	char method[5];
+	char wc_method[5] = "WC";
+
+	if (!guid_string || !out)
+		return AE_BAD_PARAMETER;
+
+	if (!find_guid(guid_string, &wblock))
+		return AE_ERROR;
+
+	block = &wblock->gblock;
+	handle = wblock->handle;
+
+	if (block->instance_count < instance)
+		return AE_BAD_PARAMETER;
+
+	/* Check GUID is a data block */
+	if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
+		return AE_ERROR;
+
+	input.count = 1;
+	input.pointer = wq_params;
+	wq_params[0].type = ACPI_TYPE_INTEGER;
+	wq_params[0].integer.value = instance;
+
+	/*
+	 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method first to
+	 * enable collection.
+	 */
+	if (block->flags & ACPI_WMI_EXPENSIVE) {
+		strncat(wc_method, block->object_id, 2);
+
+		/*
+		 * Some GUIDs break the specification by declaring themselves
+		 * expensive, but have no corresponding WCxx method. So we
+		 * should not fail if this happens.
+		 */
+		if (acpi_has_method(handle, wc_method))
+			wc_status = acpi_execute_simple_method(handle,
+								wc_method, 1);
+	}
+
+	strcpy(method, "WQ");
+	strncat(method, block->object_id, 2);
+
+	status = acpi_evaluate_object(handle, method, &input, out);
+
+	/*
+	 * If ACPI_WMI_EXPENSIVE, call the relevant WCxx method, even if
+	 * the WQxx method failed - we should disable collection anyway.
+	 */
+	if ((block->flags & ACPI_WMI_EXPENSIVE) && ACPI_SUCCESS(wc_status)) {
+		status = acpi_execute_simple_method(handle, wc_method, 0);
+	}
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(wmi_query_block);
+
+/**
+ * wmi_set_block - Write to a WMI block
+ * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ * @instance: Instance index
+ * &in: Buffer containing new values for the data block
+ *
+ * Write the contents of the input buffer to an ACPI-WMI data block
+ */
+acpi_status wmi_set_block(const char *guid_string, u8 instance,
+const struct acpi_buffer *in)
+{
+	struct guid_block *block = NULL;
+	struct wmi_block *wblock = NULL;
+	acpi_handle handle;
+	struct acpi_object_list input;
+	union acpi_object params[2];
+	char method[5] = "WS";
+
+	if (!guid_string || !in)
+		return AE_BAD_DATA;
+
+	if (!find_guid(guid_string, &wblock))
+		return AE_ERROR;
+
+	block = &wblock->gblock;
+	handle = wblock->handle;
+
+	if (block->instance_count < instance)
+		return AE_BAD_PARAMETER;
+
+	/* Check GUID is a data block */
+	if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
+		return AE_ERROR;
+
+	input.count = 2;
+	input.pointer = params;
+	params[0].type = ACPI_TYPE_INTEGER;
+	params[0].integer.value = instance;
+
+	if (block->flags & ACPI_WMI_STRING) {
+		params[1].type = ACPI_TYPE_STRING;
+	} else {
+		params[1].type = ACPI_TYPE_BUFFER;
+	}
+	params[1].buffer.length = in->length;
+	params[1].buffer.pointer = in->pointer;
+
+	strncat(method, block->object_id, 2);
+
+	return acpi_evaluate_object(handle, method, &input, NULL);
+}
+EXPORT_SYMBOL_GPL(wmi_set_block);
+
+static void wmi_dump_wdg(const struct guid_block *g)
+{
+	char guid_string[37];
+
+	wmi_gtoa(g->guid, guid_string);
+
+	pr_info("%s:\n", guid_string);
+	pr_info("\tobject_id: %c%c\n", g->object_id[0], g->object_id[1]);
+	pr_info("\tnotify_id: %02X\n", g->notify_id);
+	pr_info("\treserved: %02X\n", g->reserved);
+	pr_info("\tinstance_count: %d\n", g->instance_count);
+	pr_info("\tflags: %#x", g->flags);
+	if (g->flags) {
+		if (g->flags & ACPI_WMI_EXPENSIVE)
+			pr_cont(" ACPI_WMI_EXPENSIVE");
+		if (g->flags & ACPI_WMI_METHOD)
+			pr_cont(" ACPI_WMI_METHOD");
+		if (g->flags & ACPI_WMI_STRING)
+			pr_cont(" ACPI_WMI_STRING");
+		if (g->flags & ACPI_WMI_EVENT)
+			pr_cont(" ACPI_WMI_EVENT");
+	}
+	pr_cont("\n");
+
+}
+
+static void wmi_notify_debug(u32 value, void *context)
+{
+	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *obj;
+	acpi_status status;
+
+	status = wmi_get_event_data(value, &response);
+	if (status != AE_OK) {
+		pr_info("bad event status 0x%x\n", status);
+		return;
+	}
+
+	obj = (union acpi_object *)response.pointer;
+
+	if (!obj)
+		return;
+
+	pr_info("DEBUG Event ");
+	switch(obj->type) {
+	case ACPI_TYPE_BUFFER:
+		pr_cont("BUFFER_TYPE - length %d\n", obj->buffer.length);
+		break;
+	case ACPI_TYPE_STRING:
+		pr_cont("STRING_TYPE - %s\n", obj->string.pointer);
+		break;
+	case ACPI_TYPE_INTEGER:
+		pr_cont("INTEGER_TYPE - %llu\n", obj->integer.value);
+		break;
+	case ACPI_TYPE_PACKAGE:
+		pr_cont("PACKAGE_TYPE - %d elements\n", obj->package.count);
+		break;
+	default:
+		pr_cont("object type 0x%X\n", obj->type);
+	}
+	kfree(obj);
+}
+
+/**
+ * wmi_install_notify_handler - Register handler for WMI events
+ * @handler: Function to handle notifications
+ * @data: Data to be returned to handler when event is fired
+ *
+ * Register a handler for events sent to the ACPI-WMI mapper device.
+ */
+acpi_status wmi_install_notify_handler(const char *guid,
+wmi_notify_handler handler, void *data)
+{
+	struct wmi_block *block;
+	acpi_status status = AE_NOT_EXIST;
+	char tmp[16], guid_input[16];
+	struct list_head *p;
+
+	if (!guid || !handler)
+		return AE_BAD_PARAMETER;
+
+	wmi_parse_guid(guid, tmp);
+	wmi_swap_bytes(tmp, guid_input);
+
+	list_for_each(p, &wmi_block_list) {
+		acpi_status wmi_status;
+		block = list_entry(p, struct wmi_block, list);
+
+		if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
+			if (block->handler &&
+			    block->handler != wmi_notify_debug)
+				return AE_ALREADY_ACQUIRED;
+
+			block->handler = handler;
+			block->handler_data = data;
+
+			wmi_status = wmi_method_enable(block, 1);
+			if ((wmi_status != AE_OK) ||
+			    ((wmi_status == AE_OK) && (status == AE_NOT_EXIST)))
+				status = wmi_status;
+		}
+	}
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
+
+/**
+ * wmi_uninstall_notify_handler - Unregister handler for WMI events
+ *
+ * Unregister handler for events sent to the ACPI-WMI mapper device.
+ */
+acpi_status wmi_remove_notify_handler(const char *guid)
+{
+	struct wmi_block *block;
+	acpi_status status = AE_NOT_EXIST;
+	char tmp[16], guid_input[16];
+	struct list_head *p;
+
+	if (!guid)
+		return AE_BAD_PARAMETER;
+
+	wmi_parse_guid(guid, tmp);
+	wmi_swap_bytes(tmp, guid_input);
+
+	list_for_each(p, &wmi_block_list) {
+		acpi_status wmi_status;
+		block = list_entry(p, struct wmi_block, list);
+
+		if (memcmp(block->gblock.guid, guid_input, 16) == 0) {
+			if (!block->handler ||
+			    block->handler == wmi_notify_debug)
+				return AE_NULL_ENTRY;
+
+			if (debug_event) {
+				block->handler = wmi_notify_debug;
+				status = AE_OK;
+			} else {
+				wmi_status = wmi_method_enable(block, 0);
+				block->handler = NULL;
+				block->handler_data = NULL;
+				if ((wmi_status != AE_OK) ||
+				    ((wmi_status == AE_OK) &&
+				     (status == AE_NOT_EXIST)))
+					status = wmi_status;
+			}
+		}
+	}
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
+
+/**
+ * wmi_get_event_data - Get WMI data associated with an event
+ *
+ * @event: Event to find
+ * @out: Buffer to hold event data. out->pointer should be freed with kfree()
+ *
+ * Returns extra data associated with an event in WMI.
+ */
+acpi_status wmi_get_event_data(u32 event, struct acpi_buffer *out)
+{
+	struct acpi_object_list input;
+	union acpi_object params[1];
+	struct guid_block *gblock;
+	struct wmi_block *wblock;
+	struct list_head *p;
+
+	input.count = 1;
+	input.pointer = params;
+	params[0].type = ACPI_TYPE_INTEGER;
+	params[0].integer.value = event;
+
+	list_for_each(p, &wmi_block_list) {
+		wblock = list_entry(p, struct wmi_block, list);
+		gblock = &wblock->gblock;
+
+		if ((gblock->flags & ACPI_WMI_EVENT) &&
+			(gblock->notify_id == event))
+			return acpi_evaluate_object(wblock->handle, "_WED",
+				&input, out);
+	}
+
+	return AE_NOT_FOUND;
+}
+EXPORT_SYMBOL_GPL(wmi_get_event_data);
+
+/**
+ * wmi_has_guid - Check if a GUID is available
+ * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ *
+ * Check if a given GUID is defined by _WDG
+ */
+bool wmi_has_guid(const char *guid_string)
+{
+	return find_guid(guid_string, NULL);
+}
+EXPORT_SYMBOL_GPL(wmi_has_guid);
+
+/*
+ * sysfs interface
+ */
+static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	char guid_string[37];
+	struct wmi_block *wblock;
+
+	wblock = dev_get_drvdata(dev);
+	if (!wblock) {
+		strcat(buf, "\n");
+		return strlen(buf);
+	}
+
+	wmi_gtoa(wblock->gblock.guid, guid_string);
+
+	return sprintf(buf, "wmi:%s\n", guid_string);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static struct attribute *wmi_attrs[] = {
+	&dev_attr_modalias.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(wmi);
+
+static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	char guid_string[37];
+
+	struct wmi_block *wblock;
+
+	if (add_uevent_var(env, "MODALIAS="))
+		return -ENOMEM;
+
+	wblock = dev_get_drvdata(dev);
+	if (!wblock)
+		return -ENOMEM;
+
+	wmi_gtoa(wblock->gblock.guid, guid_string);
+
+	strcpy(&env->buf[env->buflen - 1], "wmi:");
+	memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
+	env->buflen += 40;
+
+	return 0;
+}
+
+static void wmi_dev_free(struct device *dev)
+{
+	struct wmi_block *wmi_block = container_of(dev, struct wmi_block, dev);
+
+	kfree(wmi_block);
+}
+
+static struct class wmi_class = {
+	.name = "wmi",
+	.dev_release = wmi_dev_free,
+	.dev_uevent = wmi_dev_uevent,
+	.dev_groups = wmi_groups,
+};
+
+static int wmi_create_device(const struct guid_block *gblock,
+			     struct wmi_block *wblock, acpi_handle handle)
+{
+	char guid_string[37];
+
+	wblock->dev.class = &wmi_class;
+
+	wmi_gtoa(gblock->guid, guid_string);
+	dev_set_name(&wblock->dev, "%s", guid_string);
+
+	dev_set_drvdata(&wblock->dev, wblock);
+
+	return device_register(&wblock->dev);
+}
+
+static void wmi_free_devices(void)
+{
+	struct wmi_block *wblock, *next;
+
+	/* Delete devices for all the GUIDs */
+	list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
+		list_del(&wblock->list);
+		if (wblock->dev.class)
+			device_unregister(&wblock->dev);
+		else
+			kfree(wblock);
+	}
+}
+
+static bool guid_already_parsed(const char *guid_string)
+{
+	struct wmi_block *wblock;
+
+	list_for_each_entry(wblock, &wmi_block_list, list)
+		if (memcmp(wblock->gblock.guid, guid_string, 16) == 0)
+			return true;
+
+	return false;
+}
+
+/*
+ * Parse the _WDG method for the GUID data blocks
+ */
+static int parse_wdg(acpi_handle handle)
+{
+	struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
+	union acpi_object *obj;
+	const struct guid_block *gblock;
+	struct wmi_block *wblock;
+	acpi_status status;
+	int retval;
+	u32 i, total;
+
+	status = acpi_evaluate_object(handle, "_WDG", NULL, &out);
+	if (ACPI_FAILURE(status))
+		return -ENXIO;
+
+	obj = (union acpi_object *) out.pointer;
+	if (!obj)
+		return -ENXIO;
+
+	if (obj->type != ACPI_TYPE_BUFFER) {
+		retval = -ENXIO;
+		goto out_free_pointer;
+	}
+
+	gblock = (const struct guid_block *)obj->buffer.pointer;
+	total = obj->buffer.length / sizeof(struct guid_block);
+
+	for (i = 0; i < total; i++) {
+		if (debug_dump_wdg)
+			wmi_dump_wdg(&gblock[i]);
+
+		wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
+		if (!wblock)
+			return -ENOMEM;
+
+		wblock->handle = handle;
+		wblock->gblock = gblock[i];
+
+		/*
+		  Some WMI devices, like those for nVidia hooks, have a
+		  duplicate GUID. It's not clear what we should do in this
+		  case yet, so for now, we'll just ignore the duplicate
+		  for device creation.
+		*/
+		if (!guid_already_parsed(gblock[i].guid)) {
+			retval = wmi_create_device(&gblock[i], wblock, handle);
+			if (retval) {
+				wmi_free_devices();
+				goto out_free_pointer;
+			}
+		}
+
+		list_add_tail(&wblock->list, &wmi_block_list);
+
+		if (debug_event) {
+			wblock->handler = wmi_notify_debug;
+			wmi_method_enable(wblock, 1);
+		}
+	}
+
+	retval = 0;
+
+out_free_pointer:
+	kfree(out.pointer);
+
+	return retval;
+}
+
+/*
+ * WMI can have EmbeddedControl access regions. In which case, we just want to
+ * hand these off to the EC driver.
+ */
+static acpi_status
+acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
+		      u32 bits, u64 *value,
+		      void *handler_context, void *region_context)
+{
+	int result = 0, i = 0;
+	u8 temp = 0;
+
+	if ((address > 0xFF) || !value)
+		return AE_BAD_PARAMETER;
+
+	if (function != ACPI_READ && function != ACPI_WRITE)
+		return AE_BAD_PARAMETER;
+
+	if (bits != 8)
+		return AE_BAD_PARAMETER;
+
+	if (function == ACPI_READ) {
+		result = ec_read(address, &temp);
+		(*value) |= ((u64)temp) << i;
+	} else {
+		temp = 0xff & ((*value) >> i);
+		result = ec_write(address, temp);
+	}
+
+	switch (result) {
+	case -EINVAL:
+		return AE_BAD_PARAMETER;
+		break;
+	case -ENODEV:
+		return AE_NOT_FOUND;
+		break;
+	case -ETIME:
+		return AE_TIME;
+		break;
+	default:
+		return AE_OK;
+	}
+}
+
+static void acpi_wmi_notify(struct acpi_device *device, u32 event)
+{
+	struct guid_block *block;
+	struct wmi_block *wblock;
+	struct list_head *p;
+	char guid_string[37];
+
+	list_for_each(p, &wmi_block_list) {
+		wblock = list_entry(p, struct wmi_block, list);
+		block = &wblock->gblock;
+
+		if ((block->flags & ACPI_WMI_EVENT) &&
+			(block->notify_id == event)) {
+			if (wblock->handler)
+				wblock->handler(event, wblock->handler_data);
+			if (debug_event) {
+				wmi_gtoa(wblock->gblock.guid, guid_string);
+				pr_info("DEBUG Event GUID: %s\n", guid_string);
+			}
+
+			acpi_bus_generate_netlink_event(
+				device->pnp.device_class, dev_name(&device->dev),
+				event, 0);
+			break;
+		}
+	}
+}
+
+static int acpi_wmi_remove(struct acpi_device *device)
+{
+	acpi_remove_address_space_handler(device->handle,
+				ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
+	wmi_free_devices();
+
+	return 0;
+}
+
+static int acpi_wmi_add(struct acpi_device *device)
+{
+	acpi_status status;
+	int error;
+
+	status = acpi_install_address_space_handler(device->handle,
+						    ACPI_ADR_SPACE_EC,
+						    &acpi_wmi_ec_space_handler,
+						    NULL, NULL);
+	if (ACPI_FAILURE(status)) {
+		pr_err("Error installing EC region handler\n");
+		return -ENODEV;
+	}
+
+	error = parse_wdg(device->handle);
+	if (error) {
+		acpi_remove_address_space_handler(device->handle,
+						  ACPI_ADR_SPACE_EC,
+						  &acpi_wmi_ec_space_handler);
+		pr_err("Failed to parse WDG method\n");
+		return error;
+	}
+
+	return 0;
+}
+
+static int __init acpi_wmi_init(void)
+{
+	int error;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	error = class_register(&wmi_class);
+	if (error)
+		return error;
+
+	error = acpi_bus_register_driver(&acpi_wmi_driver);
+	if (error) {
+		pr_err("Error loading mapper\n");
+		class_unregister(&wmi_class);
+		return error;
+	}
+
+	pr_info("Mapper loaded\n");
+	return 0;
+}
+
+static void __exit acpi_wmi_exit(void)
+{
+	acpi_bus_unregister_driver(&acpi_wmi_driver);
+	class_unregister(&wmi_class);
+
+	pr_info("Mapper unloaded\n");
+}
+
+subsys_initcall(acpi_wmi_init);
+module_exit(acpi_wmi_exit);