drivers/platform/x86/eeepc-wmi.c - maze/linux - Git at Google

 /*
  * Eee PC WMI hotkey driver
  *
  * Copyright(C) 2010 Intel Corporation.
  *
  * Portions based on wistron_btns.c:
  * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
  * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
  * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
  *
  *  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/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/input.h>
 #include <linux/input/sparse-keymap.h>
 #include <linux/fb.h>
 #include <linux/backlight.h>
 #include <linux/platform_device.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>

 #define	EEEPC_WMI_FILE	"eeepc-wmi"

 MODULE_AUTHOR("Yong Wang <yong.y.wang@intel.com>");
 MODULE_DESCRIPTION("Eee PC WMI Hotkey Driver");
 MODULE_LICENSE("GPL");

 #define EEEPC_WMI_EVENT_GUID	"ABBC0F72-8EA1-11D1-00A0-C90629100000"
 #define EEEPC_WMI_MGMT_GUID	"97845ED0-4E6D-11DE-8A39-0800200C9A66"

 MODULE_ALIAS("wmi:"EEEPC_WMI_EVENT_GUID);
 MODULE_ALIAS("wmi:"EEEPC_WMI_MGMT_GUID);

 #define NOTIFY_BRNUP_MIN	0x11
 #define NOTIFY_BRNUP_MAX	0x1f
 #define NOTIFY_BRNDOWN_MIN	0x20
 #define NOTIFY_BRNDOWN_MAX	0x2e

 #define EEEPC_WMI_METHODID_DEVS	0x53564544
 #define EEEPC_WMI_METHODID_DSTS	0x53544344

 #define EEEPC_WMI_DEVID_BACKLIGHT	0x00050012

 static const struct key_entry eeepc_wmi_keymap[] = {
 	/* Sleep already handled via generic ACPI code */
 	{ KE_KEY, 0x5d, { KEY_WLAN } },
 	{ KE_KEY, 0x32, { KEY_MUTE } },
 	{ KE_KEY, 0x31, { KEY_VOLUMEDOWN } },
 	{ KE_KEY, 0x30, { KEY_VOLUMEUP } },
 	{ KE_IGNORE, NOTIFY_BRNDOWN_MIN, { KEY_BRIGHTNESSDOWN } },
 	{ KE_IGNORE, NOTIFY_BRNUP_MIN, { KEY_BRIGHTNESSUP } },
 	{ KE_KEY, 0xcc, { KEY_SWITCHVIDEOMODE } },
 	{ KE_END, 0},
 };

 struct bios_args {
 	u32	dev_id;
 	u32	ctrl_param;
 };

 struct eeepc_wmi {
 	struct input_dev *inputdev;
 	struct backlight_device *backlight_device;
 };

 static struct platform_device *platform_device;

 static int eeepc_wmi_input_init(struct eeepc_wmi *eeepc)
 {
 	int err;

 	eeepc->inputdev = input_allocate_device();
 	if (!eeepc->inputdev)
 		return -ENOMEM;

 	eeepc->inputdev->name = "Eee PC WMI hotkeys";
 	eeepc->inputdev->phys = EEEPC_WMI_FILE "/input0";
 	eeepc->inputdev->id.bustype = BUS_HOST;
 	eeepc->inputdev->dev.parent = &platform_device->dev;

 	err = sparse_keymap_setup(eeepc->inputdev, eeepc_wmi_keymap, NULL);
 	if (err)
 		goto err_free_dev;

 	err = input_register_device(eeepc->inputdev);
 	if (err)
 		goto err_free_keymap;

 	return 0;

 err_free_keymap:
 	sparse_keymap_free(eeepc->inputdev);
 err_free_dev:
 	input_free_device(eeepc->inputdev);
 	return err;
 }

 static void eeepc_wmi_input_exit(struct eeepc_wmi *eeepc)
 {
 	if (eeepc->inputdev) {
 		sparse_keymap_free(eeepc->inputdev);
 		input_unregister_device(eeepc->inputdev);
 	}

 	eeepc->inputdev = NULL;
 }

 static acpi_status eeepc_wmi_get_devstate(u32 dev_id, u32 *ctrl_param)
 {
 	struct acpi_buffer input = { (acpi_size)sizeof(u32), &dev_id };
 	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
 	union acpi_object *obj;
 	acpi_status status;
 	u32 tmp;

 	status = wmi_evaluate_method(EEEPC_WMI_MGMT_GUID,
 			1, EEEPC_WMI_METHODID_DSTS, &input, &output);

 	if (ACPI_FAILURE(status))
 		return status;

 	obj = (union acpi_object *)output.pointer;
 	if (obj && obj->type == ACPI_TYPE_INTEGER)
 		tmp = (u32)obj->integer.value;
 	else
 		tmp = 0;

 	if (ctrl_param)
 		*ctrl_param = tmp;

 	kfree(obj);

 	return status;

 }

 static acpi_status eeepc_wmi_set_devstate(u32 dev_id, u32 ctrl_param)
 {
 	struct bios_args args = {
 		.dev_id = dev_id,
 		.ctrl_param = ctrl_param,
 	};
 	struct acpi_buffer input = { (acpi_size)sizeof(args), &args };
 	acpi_status status;

 	status = wmi_evaluate_method(EEEPC_WMI_MGMT_GUID,
 			1, EEEPC_WMI_METHODID_DEVS, &input, NULL);

 	return status;
 }

 static int read_brightness(struct backlight_device *bd)
 {
 	static u32 ctrl_param;
 	acpi_status status;

 	status = eeepc_wmi_get_devstate(EEEPC_WMI_DEVID_BACKLIGHT, &ctrl_param);

 	if (ACPI_FAILURE(status))
 		return -1;
 	else
 		return ctrl_param & 0xFF;
 }

 static int update_bl_status(struct backlight_device *bd)
 {

 	static u32 ctrl_param;
 	acpi_status status;

 	ctrl_param = bd->props.brightness;

 	status = eeepc_wmi_set_devstate(EEEPC_WMI_DEVID_BACKLIGHT, ctrl_param);

 	if (ACPI_FAILURE(status))
 		return -1;
 	else
 		return 0;
 }

 static const struct backlight_ops eeepc_wmi_bl_ops = {
 	.get_brightness = read_brightness,
 	.update_status = update_bl_status,
 };

 static int eeepc_wmi_backlight_notify(struct eeepc_wmi *eeepc, int code)
 {
 	struct backlight_device *bd = eeepc->backlight_device;
 	int old = bd->props.brightness;
 	int new;

 	if (code >= NOTIFY_BRNUP_MIN && code <= NOTIFY_BRNUP_MAX)
 		new = code - NOTIFY_BRNUP_MIN + 1;
 	else if (code >= NOTIFY_BRNDOWN_MIN && code <= NOTIFY_BRNDOWN_MAX)
 		new = code - NOTIFY_BRNDOWN_MIN;

 	bd->props.brightness = new;
 	backlight_update_status(bd);
 	backlight_force_update(bd, BACKLIGHT_UPDATE_HOTKEY);

 	return old;
 }

 static int eeepc_wmi_backlight_init(struct eeepc_wmi *eeepc)
 {
 	struct backlight_device *bd;
 	struct backlight_properties props;

 	memset(&props, 0, sizeof(struct backlight_properties));
 	props.max_brightness = 15;
 	bd = backlight_device_register(EEEPC_WMI_FILE,
 				       &platform_device->dev, eeepc,
 				       &eeepc_wmi_bl_ops, &props);
 	if (IS_ERR(bd)) {
 		pr_err("Could not register backlight device\n");
 		return PTR_ERR(bd);
 	}

 	eeepc->backlight_device = bd;

 	bd->props.brightness = read_brightness(bd);
 	bd->props.power = FB_BLANK_UNBLANK;
 	backlight_update_status(bd);

 	return 0;
 }

 static void eeepc_wmi_backlight_exit(struct eeepc_wmi *eeepc)
 {
 	if (eeepc->backlight_device)
 		backlight_device_unregister(eeepc->backlight_device);

 	eeepc->backlight_device = NULL;
 }

 static void eeepc_wmi_notify(u32 value, void *context)
 {
 	struct eeepc_wmi *eeepc = context;
 	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 	union acpi_object *obj;
 	acpi_status status;
 	int code;
 	int orig_code;

 	status = wmi_get_event_data(value, &response);
 	if (status != AE_OK) {
 		pr_err("bad event status 0x%x\n", status);
 		return;
 	}

 	obj = (union acpi_object *)response.pointer;

 	if (obj && obj->type == ACPI_TYPE_INTEGER) {
 		code = obj->integer.value;
 		orig_code = code;

 		if (code >= NOTIFY_BRNUP_MIN && code <= NOTIFY_BRNUP_MAX)
 			code = NOTIFY_BRNUP_MIN;
 		else if (code >= NOTIFY_BRNDOWN_MIN &&
 			 code <= NOTIFY_BRNDOWN_MAX)
 			code = NOTIFY_BRNDOWN_MIN;

 		if (code == NOTIFY_BRNUP_MIN || code == NOTIFY_BRNDOWN_MIN) {
 			if (!acpi_video_backlight_support())
 				eeepc_wmi_backlight_notify(eeepc, orig_code);
 		}

 		if (!sparse_keymap_report_event(eeepc->inputdev,
 						code, 1, true))
 			pr_info("Unknown key %x pressed\n", code);
 	}

 	kfree(obj);
 }

 static int __devinit eeepc_wmi_platform_probe(struct platform_device *device)
 {
 	struct eeepc_wmi *eeepc;
 	int err;
 	acpi_status status;

 	eeepc = platform_get_drvdata(device);

 	err = eeepc_wmi_input_init(eeepc);
 	if (err)
 		goto error_input;

 	if (!acpi_video_backlight_support()) {
 		err = eeepc_wmi_backlight_init(eeepc);
 		if (err)
 			goto error_backlight;
 	} else
 		pr_info("Backlight controlled by ACPI video driver\n");

 	status = wmi_install_notify_handler(EEEPC_WMI_EVENT_GUID,
 					eeepc_wmi_notify, eeepc);
 	if (ACPI_FAILURE(status)) {
 		pr_err("Unable to register notify handler - %d\n",
 			status);
 		err = -ENODEV;
 		goto error_wmi;
 	}

 	return 0;

 error_wmi:
 	eeepc_wmi_backlight_exit(eeepc);
 error_backlight:
 	eeepc_wmi_input_exit(eeepc);
 error_input:
 	return err;
 }

 static int __devexit eeepc_wmi_platform_remove(struct platform_device *device)
 {
 	struct eeepc_wmi *eeepc;

 	eeepc = platform_get_drvdata(device);
 	wmi_remove_notify_handler(EEEPC_WMI_EVENT_GUID);
 	eeepc_wmi_backlight_exit(eeepc);
 	eeepc_wmi_input_exit(eeepc);

 	return 0;
 }

 static struct platform_driver platform_driver = {
 	.driver = {
 		.name = EEEPC_WMI_FILE,
 		.owner = THIS_MODULE,
 	},
 	.probe = eeepc_wmi_platform_probe,
 	.remove = __devexit_p(eeepc_wmi_platform_remove),
 };

 static int __init eeepc_wmi_init(void)
 {
 	struct eeepc_wmi *eeepc;
 	int err;

 	if (!wmi_has_guid(EEEPC_WMI_EVENT_GUID) ||
 	    !wmi_has_guid(EEEPC_WMI_MGMT_GUID)) {
 		pr_warning("No known WMI GUID found\n");
 		return -ENODEV;
 	}

 	eeepc = kzalloc(sizeof(struct eeepc_wmi), GFP_KERNEL);
 	if (!eeepc)
 		return -ENOMEM;

 	platform_device = platform_device_alloc(EEEPC_WMI_FILE, -1);
 	if (!platform_device) {
 		pr_warning("Unable to allocate platform device\n");
 		err = -ENOMEM;
 		goto fail_platform;
 	}

 	err = platform_device_add(platform_device);
 	if (err) {
 		pr_warning("Unable to add platform device\n");
 		goto put_dev;
 	}

 	platform_set_drvdata(platform_device, eeepc);

 	err = platform_driver_register(&platform_driver);
 	if (err) {
 		pr_warning("Unable to register platform driver\n");
 		goto del_dev;
 	}

 	return 0;

 del_dev:
 	platform_device_del(platform_device);
 put_dev:
 	platform_device_put(platform_device);
 fail_platform:
 	kfree(eeepc);

 	return err;
 }

 static void __exit eeepc_wmi_exit(void)
 {
 	struct eeepc_wmi *eeepc;

 	eeepc = platform_get_drvdata(platform_device);
 	platform_driver_unregister(&platform_driver);
 	platform_device_unregister(platform_device);
 	kfree(eeepc);
 }

 module_init(eeepc_wmi_init);
 module_exit(eeepc_wmi_exit);
	/*
	* Eee PC WMI hotkey driver
	*
	* Copyright(C) 2010 Intel Corporation.
	*
	* Portions based on wistron_btns.c:
	* Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
	* Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
	* Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
	*
	* 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/module.h>
	#include <linux/init.h>
	#include <linux/types.h>
	#include <linux/slab.h>
	#include <linux/input.h>
	#include <linux/input/sparse-keymap.h>
	#include <linux/fb.h>
	#include <linux/backlight.h>
	#include <linux/platform_device.h>
	#include <acpi/acpi_bus.h>
	#include <acpi/acpi_drivers.h>

	#define EEEPC_WMI_FILE "eeepc-wmi"

	MODULE_AUTHOR("Yong Wang <yong.y.wang@intel.com>");
	MODULE_DESCRIPTION("Eee PC WMI Hotkey Driver");
	MODULE_LICENSE("GPL");

	#define EEEPC_WMI_EVENT_GUID "ABBC0F72-8EA1-11D1-00A0-C90629100000"
	#define EEEPC_WMI_MGMT_GUID "97845ED0-4E6D-11DE-8A39-0800200C9A66"

	MODULE_ALIAS("wmi:"EEEPC_WMI_EVENT_GUID);
	MODULE_ALIAS("wmi:"EEEPC_WMI_MGMT_GUID);

	#define NOTIFY_BRNUP_MIN 0x11
	#define NOTIFY_BRNUP_MAX 0x1f
	#define NOTIFY_BRNDOWN_MIN 0x20
	#define NOTIFY_BRNDOWN_MAX 0x2e

	#define EEEPC_WMI_METHODID_DEVS 0x53564544
	#define EEEPC_WMI_METHODID_DSTS 0x53544344

	#define EEEPC_WMI_DEVID_BACKLIGHT 0x00050012

	static const struct key_entry eeepc_wmi_keymap[] = {
	/* Sleep already handled via generic ACPI code */
	{ KE_KEY, 0x5d, { KEY_WLAN } },
	{ KE_KEY, 0x32, { KEY_MUTE } },
	{ KE_KEY, 0x31, { KEY_VOLUMEDOWN } },
	{ KE_KEY, 0x30, { KEY_VOLUMEUP } },
	{ KE_IGNORE, NOTIFY_BRNDOWN_MIN, { KEY_BRIGHTNESSDOWN } },
	{ KE_IGNORE, NOTIFY_BRNUP_MIN, { KEY_BRIGHTNESSUP } },
	{ KE_KEY, 0xcc, { KEY_SWITCHVIDEOMODE } },
	{ KE_END, 0},
	};

	struct bios_args {
	u32 dev_id;
	u32 ctrl_param;
	};

	struct eeepc_wmi {
	struct input_dev *inputdev;
	struct backlight_device *backlight_device;
	};

	static struct platform_device *platform_device;

	static int eeepc_wmi_input_init(struct eeepc_wmi *eeepc)
	{
	int err;

	eeepc->inputdev = input_allocate_device();
	if (!eeepc->inputdev)
	return -ENOMEM;

	eeepc->inputdev->name = "Eee PC WMI hotkeys";
	eeepc->inputdev->phys = EEEPC_WMI_FILE "/input0";
	eeepc->inputdev->id.bustype = BUS_HOST;
	eeepc->inputdev->dev.parent = &platform_device->dev;

	err = sparse_keymap_setup(eeepc->inputdev, eeepc_wmi_keymap, NULL);
	if (err)
	goto err_free_dev;

	err = input_register_device(eeepc->inputdev);
	if (err)
	goto err_free_keymap;

	return 0;

	err_free_keymap:
	sparse_keymap_free(eeepc->inputdev);
	err_free_dev:
	input_free_device(eeepc->inputdev);
	return err;
	}

	static void eeepc_wmi_input_exit(struct eeepc_wmi *eeepc)
	{
	if (eeepc->inputdev) {
	sparse_keymap_free(eeepc->inputdev);
	input_unregister_device(eeepc->inputdev);
	}

	eeepc->inputdev = NULL;
	}

	static acpi_status eeepc_wmi_get_devstate(u32 dev_id, u32 *ctrl_param)
	{
	struct acpi_buffer input = { (acpi_size)sizeof(u32), &dev_id };
	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;
	acpi_status status;
	u32 tmp;

	status = wmi_evaluate_method(EEEPC_WMI_MGMT_GUID,
	1, EEEPC_WMI_METHODID_DSTS, &input, &output);

	if (ACPI_FAILURE(status))
	return status;

	obj = (union acpi_object *)output.pointer;
	if (obj && obj->type == ACPI_TYPE_INTEGER)
	tmp = (u32)obj->integer.value;
	else
	tmp = 0;

	if (ctrl_param)
	*ctrl_param = tmp;

	kfree(obj);

	return status;

	}

	static acpi_status eeepc_wmi_set_devstate(u32 dev_id, u32 ctrl_param)
	{
	struct bios_args args = {
	.dev_id = dev_id,
	.ctrl_param = ctrl_param,
	};
	struct acpi_buffer input = { (acpi_size)sizeof(args), &args };
	acpi_status status;

	status = wmi_evaluate_method(EEEPC_WMI_MGMT_GUID,
	1, EEEPC_WMI_METHODID_DEVS, &input, NULL);

	return status;
	}

	static int read_brightness(struct backlight_device *bd)
	{
	static u32 ctrl_param;
	acpi_status status;

	status = eeepc_wmi_get_devstate(EEEPC_WMI_DEVID_BACKLIGHT, &ctrl_param);

	if (ACPI_FAILURE(status))
	return -1;
	else
	return ctrl_param & 0xFF;
	}

	static int update_bl_status(struct backlight_device *bd)
	{

	static u32 ctrl_param;
	acpi_status status;

	ctrl_param = bd->props.brightness;

	status = eeepc_wmi_set_devstate(EEEPC_WMI_DEVID_BACKLIGHT, ctrl_param);

	if (ACPI_FAILURE(status))
	return -1;
	else
	return 0;
	}

	static const struct backlight_ops eeepc_wmi_bl_ops = {
	.get_brightness = read_brightness,
	.update_status = update_bl_status,
	};

	static int eeepc_wmi_backlight_notify(struct eeepc_wmi *eeepc, int code)
	{
	struct backlight_device *bd = eeepc->backlight_device;
	int old = bd->props.brightness;
	int new;

	if (code >= NOTIFY_BRNUP_MIN && code <= NOTIFY_BRNUP_MAX)
	new = code - NOTIFY_BRNUP_MIN + 1;
	else if (code >= NOTIFY_BRNDOWN_MIN && code <= NOTIFY_BRNDOWN_MAX)
	new = code - NOTIFY_BRNDOWN_MIN;

	bd->props.brightness = new;
	backlight_update_status(bd);
	backlight_force_update(bd, BACKLIGHT_UPDATE_HOTKEY);

	return old;
	}

	static int eeepc_wmi_backlight_init(struct eeepc_wmi *eeepc)
	{
	struct backlight_device *bd;
	struct backlight_properties props;

	memset(&props, 0, sizeof(struct backlight_properties));
	props.max_brightness = 15;
	bd = backlight_device_register(EEEPC_WMI_FILE,
	&platform_device->dev, eeepc,
	&eeepc_wmi_bl_ops, &props);
	if (IS_ERR(bd)) {
	pr_err("Could not register backlight device\n");
	return PTR_ERR(bd);
	}

	eeepc->backlight_device = bd;

	bd->props.brightness = read_brightness(bd);
	bd->props.power = FB_BLANK_UNBLANK;
	backlight_update_status(bd);

	return 0;
	}

	static void eeepc_wmi_backlight_exit(struct eeepc_wmi *eeepc)
	{
	if (eeepc->backlight_device)
	backlight_device_unregister(eeepc->backlight_device);

	eeepc->backlight_device = NULL;
	}

	static void eeepc_wmi_notify(u32 value, void *context)
	{
	struct eeepc_wmi *eeepc = context;
	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;
	acpi_status status;
	int code;
	int orig_code;

	status = wmi_get_event_data(value, &response);
	if (status != AE_OK) {
	pr_err("bad event status 0x%x\n", status);
	return;
	}

	obj = (union acpi_object *)response.pointer;

	if (obj && obj->type == ACPI_TYPE_INTEGER) {
	code = obj->integer.value;
	orig_code = code;

	if (code >= NOTIFY_BRNUP_MIN && code <= NOTIFY_BRNUP_MAX)
	code = NOTIFY_BRNUP_MIN;
	else if (code >= NOTIFY_BRNDOWN_MIN &&
	code <= NOTIFY_BRNDOWN_MAX)
	code = NOTIFY_BRNDOWN_MIN;

	if (code == NOTIFY_BRNUP_MIN \|\| code == NOTIFY_BRNDOWN_MIN) {
	if (!acpi_video_backlight_support())
	eeepc_wmi_backlight_notify(eeepc, orig_code);
	}

	if (!sparse_keymap_report_event(eeepc->inputdev,
	code, 1, true))
	pr_info("Unknown key %x pressed\n", code);
	}

	kfree(obj);
	}

	static int __devinit eeepc_wmi_platform_probe(struct platform_device *device)
	{
	struct eeepc_wmi *eeepc;
	int err;
	acpi_status status;

	eeepc = platform_get_drvdata(device);

	err = eeepc_wmi_input_init(eeepc);
	if (err)
	goto error_input;

	if (!acpi_video_backlight_support()) {
	err = eeepc_wmi_backlight_init(eeepc);
	if (err)
	goto error_backlight;
	} else
	pr_info("Backlight controlled by ACPI video driver\n");

	status = wmi_install_notify_handler(EEEPC_WMI_EVENT_GUID,
	eeepc_wmi_notify, eeepc);
	if (ACPI_FAILURE(status)) {
	pr_err("Unable to register notify handler - %d\n",
	status);
	err = -ENODEV;
	goto error_wmi;
	}

	return 0;

	error_wmi:
	eeepc_wmi_backlight_exit(eeepc);
	error_backlight:
	eeepc_wmi_input_exit(eeepc);
	error_input:
	return err;
	}

	static int __devexit eeepc_wmi_platform_remove(struct platform_device *device)
	{
	struct eeepc_wmi *eeepc;

	eeepc = platform_get_drvdata(device);
	wmi_remove_notify_handler(EEEPC_WMI_EVENT_GUID);
	eeepc_wmi_backlight_exit(eeepc);
	eeepc_wmi_input_exit(eeepc);

	return 0;
	}

	static struct platform_driver platform_driver = {
	.driver = {
	.name = EEEPC_WMI_FILE,
	.owner = THIS_MODULE,
	},
	.probe = eeepc_wmi_platform_probe,
	.remove = __devexit_p(eeepc_wmi_platform_remove),
	};

	static int __init eeepc_wmi_init(void)
	{
	struct eeepc_wmi *eeepc;
	int err;

	if (!wmi_has_guid(EEEPC_WMI_EVENT_GUID) \|\|
	!wmi_has_guid(EEEPC_WMI_MGMT_GUID)) {
	pr_warning("No known WMI GUID found\n");
	return -ENODEV;
	}

	eeepc = kzalloc(sizeof(struct eeepc_wmi), GFP_KERNEL);
	if (!eeepc)
	return -ENOMEM;

	platform_device = platform_device_alloc(EEEPC_WMI_FILE, -1);
	if (!platform_device) {
	pr_warning("Unable to allocate platform device\n");
	err = -ENOMEM;
	goto fail_platform;
	}

	err = platform_device_add(platform_device);
	if (err) {
	pr_warning("Unable to add platform device\n");
	goto put_dev;
	}

	platform_set_drvdata(platform_device, eeepc);

	err = platform_driver_register(&platform_driver);
	if (err) {
	pr_warning("Unable to register platform driver\n");
	goto del_dev;
	}

	return 0;

	del_dev:
	platform_device_del(platform_device);
	put_dev:
	platform_device_put(platform_device);
	fail_platform:
	kfree(eeepc);

	return err;
	}

	static void __exit eeepc_wmi_exit(void)
	{
	struct eeepc_wmi *eeepc;

	eeepc = platform_get_drvdata(platform_device);
	platform_driver_unregister(&platform_driver);
	platform_device_unregister(platform_device);
	kfree(eeepc);
	}

	module_init(eeepc_wmi_init);
	module_exit(eeepc_wmi_exit);