[PATCH] drivers/x86: add thinkpad-wmi

[Corentin Chary]

This driver has been available on https://github.com/iksaif/thinkpad-wmi for
a few year and is already deployed on large fleets of thinkpad laptops.

The WMI interface is documented here: http://download.lenovo.com/ibmdl/pub/pc/pccbbs/thinkcentre_pdf/hrdeploy_en.pdf
It mostly focused on changing BIOS/Firmware settings.

Signed-off-by: Corentin Chary <corentin.chary@xxxxxxxxx>
---
 .../ABI/testing/sysfs-platform-thinkpad-wmi        |   50 +
 drivers/platform/x86/Kconfig                       |   10 +
 drivers/platform/x86/Makefile                      |    1 +
 drivers/platform/x86/thinkpad-wmi.c                | 1217 ++++++++++++++++++++
 4 files changed, 1278 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-platform-thinkpad-wmi
 create mode 100644 drivers/platform/x86/thinkpad-wmi.c

diff --git a/Documentation/ABI/testing/sysfs-platform-thinkpad-wmi b/Documentation/ABI/testing/sysfs-platform-thinkpad-wmi
new file mode 100644
index 000000000000..c3673876c5b3
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-platform-thinkpad-wmi
@@ -0,0 +1,50 @@
+What:		/sys/devices/platform/thinkpad-wmi/password
+Date:		Aug 2017
+KernelVersion:	4.14
+Contact:	"Corentin Chary" <corentin.chary@xxxxxxxxx>
+Description:
+		BIOS password needs to be written in this file if set
+		to be able to change BIOS settings.
+
+What:		/sys/devices/platform/thinkpad-wmi/password_encoding
+Date:		Aug 2017
+KernelVersion:	4.14
+Contact:	"Corentin Chary" <corentin.chary@xxxxxxxxx>
+Description:
+		Password encoding ('ascii' or 'scanmode').
+
+What:		/sys/devices/platform/thinkpad-wmi/password_kbd_lang
+Date:		Aug 2017
+KernelVersion:	4.14
+Contact:	"Corentin Chary" <corentin.chary@xxxxxxxxx>
+Description:
+		Keyboard language used for password. One of 'us', 'fr' and 'gr'.
+
+What:		/sys/devices/platform/thinkpad-wmi/password_type
+Date:		Aug 2017
+KernelVersion:	4.14
+Contact:	"Corentin Chary" <corentin.chary@xxxxxxxxx>
+Description:
+		Password type to be changed when password_change is written to, e.g. 'pap'.
+
+What:		/sys/devices/platform/thinkpad-wmi/password_change
+Date:		Aug 2017
+KernelVersion:	4.14
+Contact:	"Corentin Chary" <corentin.chary@xxxxxxxxx>
+Description:
+		Writing to this file will set the password specified in password_type.
+		The new password will not take effect until the next reboot.
+
+What:		/sys/devices/platform/thinkpad-wmi/password_settings
+Date:		Oct 2015
+KernelVersion:	4.14
+Contact:	"Corentin Chary" <corentin.chary@xxxxxxxxx>
+Description:
+		Display various password settings.
+
+What:		/sys/devices/platform/thinkpad-wmi/load_default_settings
+Date:		Oct 2015
+KernelVersion:	4.14
+Contact:	"Corentin Chary" <corentin.chary@xxxxxxxxx>
+Description:
+		Write anything to this file to load default BIOS settings.
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 80b87954f6dd..4e2e8a04228a 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -511,6 +511,16 @@ config THINKPAD_ACPI_HOTKEY_POLL
 	  If you are not sure, say Y here.  The driver enables polling only if
 	  it is strictly necessary to do so.
 
+config THINKPAD_WMI
+	tristate "THINKPAD WMI Driver (EXPERIMENTAL)"
+	depends on ACPI_WMI
+	---help---
+	  This driver allow you to modify BIOS passwords, settings, and boot order
+	  using Windows Management Instrumentation (WMI) through the Lenovo
+	  client-management interface.
+
+	  Say Y here if you have a WMI aware Thinkpad.
+
 config SENSORS_HDAPS
 	tristate "Thinkpad Hard Drive Active Protection System (hdaps)"
 	depends on INPUT
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 91cec1751461..3b03f0744794 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_TC1100_WMI)	+= tc1100-wmi.o
 obj-$(CONFIG_SONY_LAPTOP)	+= sony-laptop.o
 obj-$(CONFIG_IDEAPAD_LAPTOP)	+= ideapad-laptop.o
 obj-$(CONFIG_THINKPAD_ACPI)	+= thinkpad_acpi.o
+obj-$(CONFIG_THINKPAD_WMI)	+= thinkpad-wmi.o
 obj-$(CONFIG_SENSORS_HDAPS)	+= hdaps.o
 obj-$(CONFIG_FUJITSU_LAPTOP)	+= fujitsu-laptop.o
 obj-$(CONFIG_FUJITSU_TABLET)	+= fujitsu-tablet.o
diff --git a/drivers/platform/x86/thinkpad-wmi.c b/drivers/platform/x86/thinkpad-wmi.c
new file mode 100644
index 000000000000..9f2d6d2c3e16
--- /dev/null
+++ b/drivers/platform/x86/thinkpad-wmi.c
@@ -0,0 +1,1217 @@
+/*
+ * Thinkpad WMI hotkey driver
+ *
+ * Copyright(C) 2012 Corentin Chary <corentin.chary@xxxxxxxxx>
+ *
+ *  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/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/seq_file.h>
+#include <linux/platform_device.h>
+#include <linux/device.h>
+#include <linux/acpi.h>
+
+#define	THINKPAD_WMI_FILE	"thinkpad-wmi"
+
+MODULE_AUTHOR("Corentin Chary <corentin.chary@xxxxxxxxx>");
+MODULE_DESCRIPTION("Thinkpad WMI Driver");
+MODULE_LICENSE("GPL");
+
+/* WMI inteface */
+
+/**
+ * Name:
+ *  Lenovo_BiosSetting
+ * Description:
+ *  Get item name and settings for current WMI instance.
+ * Type:
+ *  Query
+ * Returns:
+ *  "Item,Value"
+ * Example:
+ *  "WakeOnLAN,Enable"
+ */
+#define LENOVO_BIOS_SETTING_GUID		\
+	"51F5230E-9677-46CD-A1CF-C0B23EE34DB7"
+
+/**
+ * Name:
+ *  Lenovo_SetBiosSetting
+ * Description:
+ *  Change the BIOS setting to the desired value using the Lenovo_SetBiosSetting
+ *  class. To save the settings, use the Lenovo_SaveBiosSetting class.
+ *  BIOS settings and values are case sensitive.
+ *  After making changes to the BIOS settings, you must reboot the computer
+ *  before the changes will take effect.
+ * Type:
+ *  Method
+ * Arguments:
+ *  "Item,Value,Password,Encoding,KbdLang;"
+ * Example:
+ *  "WakeOnLAN,Disable,pswd,ascii,us;"
+ */
+#define LENOVO_SET_BIOS_SETTINGS_GUID		\
+	"98479A64-33F5-4E33-A707-8E251EBBC3A1"
+
+/**
+ * Name:
+ *  Lenovo_SaveBiosSettings
+ * Description:
+ *  Save any pending changes in settings.
+ * Type:
+ *  Method
+ * Arguments:
+ *  "Password,Encoding,KbdLang;"
+ * Example:
+ * "pswd,ascii,us;"
+ */
+#define LENOVO_SAVE_BIOS_SETTINGS_GUID		\
+	"6A4B54EF-A5ED-4D33-9455-B0D9B48DF4B3"
+
+
+/**
+ * Name:
+ *  Lenovo_DiscardBiosSettings
+ * Description:
+ *  Discard any pending changes in settings.
+ * Type:
+ *  Method
+ * Arguments:
+ *  "Password,Encoding,KbdLang;"
+ * Example:
+ *  "pswd,ascii,us;"
+ */
+#define LENOVO_DISCARD_BIOS_SETTINGS_GUID	\
+	"74F1EBB6-927A-4C7D-95DF-698E21E80EB5"
+
+/**
+ * Name:
+ *  Lenovo_LoadDefaultSettings
+ * Description:
+ *  Load default BIOS settings. Use Lenovo_SaveBiosSettings to save the
+ *  settings.
+ * Type:
+ *  Method
+ * Arguments:
+ *  "Password,Encoding,KbdLang;"
+ * Example:
+ *  "pswd,ascii,us;"
+ */
+#define LENOVO_LOAD_DEFAULT_SETTINGS_GUID	\
+	"7EEF04FF-4328-447C-B5BB-D449925D538D"
+
+/**
+ * Name:
+ *  Lenovo_BiosPasswordSettings
+ * Description:
+ *  Return BIOS Password settings
+ * Type:
+ *  Query
+ * Returns:
+ *  PasswordMode, PasswordState, MinLength, MaxLength,
+ *  SupportedEncoding, SupportedKeyboard
+ */
+#define LENOVO_BIOS_PASSWORD_SETTINGS_GUID		\
+	"8ADB159E-1E32-455C-BC93-308A7ED98246"
+
+/**
+ * Name:
+ *  Lenovo_SetBiosPassword
+ * Description:
+ *  Change a specific password.
+ *  - BIOS settings cannot be changed at the same boot as power-on
+ *    passwords (POP) and hard disk passwords (HDP). If you want to change
+ *    BIOS settings and POP or HDP, you must reboot the system after changing
+ *    one of them.
+ *  - A password cannot be set using this method when one does not already
+ *    exist. Passwords can only be updated or cleared.
+ * Type:
+ *  Method
+ * Arguments:
+ *  "PasswordType,CurrentPassword,NewPassword,Encoding,KbdLang;"
+ * Example:
+ *  "pop,oldpop,newpop,ascii,us;â
+ */
+#define LENOVO_SET_BIOS_PASSWORD_GUID	\
+	"2651D9FD-911C-4B69-B94E-D0DED5963BD7"
+
+/**
+ * Name:
+ *  Lenovo_GetBiosSelections
+ * Description:
+ *  Return a list valid settings for a given item.
+ * Type:
+ *  Method
+ * Arguments:
+ *  "Item"
+ * Returns:
+ *  "Value1,Value2,Value3,..."
+ * Example:
+ *  -> "FlashOverLAN"
+ *  <- "Enabled,Disabled"
+ */
+#define LENOVO_GET_BIOS_SELECTIONS_GUID	\
+	"7364651A-132F-4FE7-ADAA-40C6C7EE2E3B"
+
+/**
+ * Name:
+ *  ???
+ * Type:
+ *  Method
+ * Arguments:
+ *  ???
+ * Example:
+ *  ???
+ * WMI-Internals:
+ *  Return big chunk of data
+ */
+#define LENOVO_QUERY_GUID			\
+	"05901221-D566-11D1-B2F0-00A0C9062910"
+
+/* Return values */
+
+enum {
+	/*
+	 * "Success"
+	 * Operation completed successfully.
+	 */
+	THINKPAD_WMI_SUCCESS = 0,
+	/*
+	 * "Not Supported"
+	 * The feature is not supported on this system.
+	 */
+	THINKPAD_WMI_NOT_SUPPORTED = -ENODEV,
+	/*
+	 * "Invalid"
+	 * The item or value provided is not valid parameter
+	 */
+	THINKPAD_WMI_INVALID = -EINVAL,
+	/*
+	 * "Access Denied"
+	 * The change could not be made due to an authentication problem.
+	 * If a supervisor password exists, the correct supervisor password
+	 * must be provided.
+	 */
+	THINKPAD_WMI_ACCESS_DENIED = -EPERM,
+	/* "System Busy"
+	 * BIOS changes have already been made that need to be committed.
+	 * Reboot the system and try again.
+	 */
+	THINKPAD_WMI_SYSTEM_BUSY = -EBUSY
+};
+
+/* Only add an alias on this one, since it's the one used
+ * in thinkpad_wmi_probe */
+MODULE_ALIAS("wmi:"LENOVO_BIOS_SETTING_GUID);
+
+struct thinkpad_wmi_pcfg {
+	uint32_t password_mode;
+	uint32_t password_state;
+	uint32_t min_length;
+	uint32_t max_length;
+	uint32_t supported_encodings;
+	uint32_t supported_keyboard;
+};
+
+/*
+ * thinkpad_wmi/       - debugfs root directory
+ *   bios_settings
+ *   bios_setting
+ *   list_valid_choices
+ *   set_bios_settings
+ *   save_bios_settings
+ *   discard_bios_settings
+ *   load_default
+ *   set_bios_password
+ *   argument
+ *   instance
+ *   instance_count
+ *   bios_password_settings
+ */
+struct thinkpad_wmi_debug {
+	struct dentry *root;
+
+	u8 instances_count;
+	u8 instance;
+	char argument[512];
+};
+
+struct thinkpad_wmi {
+	struct platform_device *platform_device;
+
+	int settings_count;
+
+	char password[64];
+	char password_encoding[64];
+	char password_kbdlang[4]; /* 2 bytes for \n\0 */
+	char auth_string[256];
+	char password_type[64];
+
+	bool can_set_bios_settings;
+	bool can_discard_bios_settings;
+	bool can_load_default_settings;
+	bool can_get_bios_selections;
+	bool can_set_bios_password;
+	bool can_get_password_settings;
+
+	char *settings[256];
+	struct dev_ext_attribute *devattrs;
+	struct thinkpad_wmi_debug debug;
+};
+
+/* helpers */
+static int thinkpad_wmi_errstr_to_err(const char *errstr)
+{
+	if (!strcmp(errstr, "Success"))
+		return THINKPAD_WMI_SUCCESS;
+	if (!strcmp(errstr, "Not Supported"))
+		return THINKPAD_WMI_NOT_SUPPORTED;
+	if (!strcmp(errstr, "Invalid"))
+		return THINKPAD_WMI_INVALID;
+	if (!strcmp(errstr, "Access Denied"))
+		return THINKPAD_WMI_ACCESS_DENIED;
+	if (!strcmp(errstr, "System Busy"))
+		return THINKPAD_WMI_SYSTEM_BUSY;
+
+	pr_debug("Unknown error string: '%s'", errstr);
+
+	return -EINVAL;
+}
+
+static int thinkpad_wmi_extract_error(const struct acpi_buffer *output)
+{
+	const union acpi_object *obj;
+	int ret;
+
+	obj = output->pointer;
+	if (!obj || obj->type != ACPI_TYPE_STRING || !obj->string.pointer)
+		return -EIO;
+
+	ret = thinkpad_wmi_errstr_to_err(obj->string.pointer);
+	kfree(obj);
+	return ret;
+}
+
+static int thinkpad_wmi_simple_call(const char *guid,
+				    const char *arg)
+{
+	const struct acpi_buffer input = { strlen(arg), (char *)arg };
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+	acpi_status status;
+
+	status = wmi_evaluate_method(guid, 0, 0, &input, &output);
+
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	return thinkpad_wmi_extract_error(&output);
+}
+
+static int thinkpad_wmi_extract_output_string(const struct acpi_buffer *output,
+					      char **string)
+{
+	const union acpi_object *obj;
+
+	obj = output->pointer;
+	if (!obj || obj->type != ACPI_TYPE_STRING || !obj->string.pointer)
+		return -EIO;
+
+	*string = kstrdup(obj->string.pointer, GFP_KERNEL);
+	kfree(obj);
+	return *string ? 0 : -ENOMEM;
+}
+
+static int thinkpad_wmi_bios_setting(int item, char **value)
+{
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+	acpi_status status;
+
+	status = wmi_query_block(LENOVO_BIOS_SETTING_GUID, item, &output);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	return thinkpad_wmi_extract_output_string(&output, value);
+}
+
+static int thinkpad_wmi_get_bios_selections(const char *item, char **value)
+{
+	const struct acpi_buffer input = { strlen(item), (char *)item };
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+	acpi_status status;
+
+	status = wmi_evaluate_method(LENOVO_GET_BIOS_SELECTIONS_GUID,
+				     0, 0, &input, &output);
+
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	return thinkpad_wmi_extract_output_string(&output, value);
+}
+
+static int thinkpad_wmi_set_bios_settings(const char *settings)
+{
+	return thinkpad_wmi_simple_call(LENOVO_SET_BIOS_SETTINGS_GUID,
+					settings);
+}
+
+static int thinkpad_wmi_save_bios_settings(const char *password)
+{
+	return thinkpad_wmi_simple_call(LENOVO_SAVE_BIOS_SETTINGS_GUID,
+					password);
+}
+
+static int thinkpad_wmi_discard_bios_settings(const char *password)
+{
+	return thinkpad_wmi_simple_call(LENOVO_DISCARD_BIOS_SETTINGS_GUID,
+					password);
+}
+
+static int thinkpad_wmi_load_default(const char *password)
+{
+	return thinkpad_wmi_simple_call(LENOVO_LOAD_DEFAULT_SETTINGS_GUID,
+					password);
+}
+
+static int thinkpad_wmi_set_bios_password(const char *settings)
+{
+	return thinkpad_wmi_simple_call(LENOVO_SET_BIOS_PASSWORD_GUID,
+					settings);
+}
+
+static int thinkpad_wmi_password_settings(struct thinkpad_wmi_pcfg *pcfg)
+{
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+	const union acpi_object *obj;
+	acpi_status status;
+
+	status = wmi_query_block(LENOVO_BIOS_PASSWORD_SETTINGS_GUID, 0,
+				 &output);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	obj = output.pointer;
+	if (!obj || obj->type != ACPI_TYPE_BUFFER || !obj->buffer.pointer)
+		return -EIO;
+	if (obj->buffer.length != sizeof(*pcfg)) {
+		pr_warn("Unknown pcfg buffer length %d\n", obj->buffer.length);
+		kfree(obj);
+		return -EIO;
+	}
+
+	memcpy(pcfg, obj->buffer.pointer, obj->buffer.length);
+	kfree(obj);
+	return 0;
+}
+
+/* sysfs */
+
+#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
+
+static ssize_t show_setting(struct device *dev,
+			     struct device_attribute *attr,
+			     char *buf)
+{
+	struct thinkpad_wmi *thinkpad = dev_get_drvdata(dev);
+	struct dev_ext_attribute *ea = to_ext_attr(attr);
+	int item = (uintptr_t)ea->var;
+	char *name = thinkpad->settings[item];
+	char *settings = NULL, *choices = NULL, *value;
+	ssize_t count = 0;
+	int ret;
+
+	ret = thinkpad_wmi_bios_setting(item, &settings);
+	if (ret)
+		return ret;
+	if (!settings)
+		return -EIO;
+
+	if (thinkpad->can_get_bios_selections) {
+		ret = thinkpad_wmi_get_bios_selections(name, &choices);
+		if (ret)
+			goto error;
+		if (!choices || !*choices) {
+			ret = -EIO;
+			goto error;
+		}
+	}
+
+	value = strchr(settings, ',');
+	if (!value)
+		goto error;
+	value++;
+
+	count = sprintf(buf, "%s\n", value);
+	if (choices)
+		count += sprintf(buf + count, "%s\n", choices);
+
+error:
+	kfree(settings);
+	kfree(choices);
+	return ret ? ret : count;
+}
+
+static ssize_t store_setting(struct device *dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct thinkpad_wmi *thinkpad = dev_get_drvdata(dev);
+	struct dev_ext_attribute *ea = to_ext_attr(attr);
+	int item_idx = (uintptr_t)ea->var;
+	const char *item = thinkpad->settings[item_idx];
+	int ret;
+	size_t buffer_size;
+	char *buffer;
+
+	/* Format: 'Item,Value,Authstring;' */
+	buffer_size = (strlen(item) + 1 + count + 1 +
+		       sizeof(thinkpad->auth_string) + 2);
+	buffer = kmalloc(buffer_size, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	strcpy(buffer, item);
+	strcat(buffer, ",");
+	strncat(buffer, buf, count);
+	if (count)
+		strim(buffer);
+	if (*thinkpad->auth_string) {
+		strcat(buffer, ",");
+		strcat(buffer, thinkpad->auth_string);
+	}
+	strcat(buffer, ";");
+
+	ret = thinkpad_wmi_set_bios_settings(buffer);
+	if (ret)
+		goto end;
+
+	ret = thinkpad_wmi_save_bios_settings(thinkpad->auth_string);
+	if (ret) {
+		/* Try to discard the settings if we failed to apply them. */
+		thinkpad_wmi_discard_bios_settings(thinkpad->auth_string);
+		goto end;
+	}
+	ret = count;
+
+end:
+	kfree(buffer);
+	return ret;
+}
+
+
+/* Password related sysfs methods */
+static ssize_t show_auth(struct thinkpad_wmi *thinkpad, char *buf,
+			 const char *data, size_t size)
+{
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	return sprintf(buf, "%s\n", data ? : "(nil)");
+}
+
+/* Create the auth string from password chunks */
+static void update_auth_string(struct thinkpad_wmi *thinkpad)
+{
+	if (!*thinkpad->password) {
+		/* No password at all */
+		thinkpad->auth_string[0] = '\0';
+		return;
+	}
+	strcpy(thinkpad->auth_string, thinkpad->password);
+
+	if (*thinkpad->password_encoding) {
+		strcat(thinkpad->auth_string, ",");
+		strcat(thinkpad->auth_string, thinkpad->password_encoding);
+	}
+
+	if (*thinkpad->password_kbdlang) {
+		strcat(thinkpad->auth_string, ",");
+		strcat(thinkpad->auth_string, thinkpad->password_kbdlang);
+	}
+}
+
+static ssize_t store_auth(struct thinkpad_wmi *thinkpad,
+			  const char *buf, size_t count,
+			  char *dst, size_t size)
+{
+	ssize_t ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (count > size - 1)
+		return -EINVAL;
+
+	/* dst may be being reused, NUL-terminate */
+	ret = strscpy(dst, buf, size);
+	if (ret < 0)
+		return ret;
+	if (count)
+		strim(dst);
+
+	update_auth_string(thinkpad);
+
+	return count;
+}
+
+#define THINKPAD_WMI_CREATE_AUTH_ATTR(_name, _uname, _mode)		\
+	static ssize_t show_##_name(struct device *dev,			\
+				    struct device_attribute *attr,	\
+				    char *buf)				\
+	{								\
+		struct thinkpad_wmi *thinkpad = dev_get_drvdata(dev);	\
+									\
+		return show_auth(thinkpad, buf,				\
+				 thinkpad->_name,			\
+				 sizeof(thinkpad->_name));		\
+	}								\
+	static ssize_t store_##_name(struct device *dev,		\
+				     struct device_attribute *attr,	\
+				     const char *buf, size_t count)	\
+	{								\
+		struct thinkpad_wmi *thinkpad = dev_get_drvdata(dev);	\
+									\
+		return store_auth(thinkpad, buf, count,			\
+				  thinkpad->_name,			\
+				  sizeof(thinkpad->_name));		\
+	}								\
+	static struct device_attribute dev_attr_##_name = {		\
+		.attr = {						\
+			.name = _uname,					\
+			.mode = _mode },				\
+		.show   = show_##_name,					\
+		.store  = store_##_name,				\
+	}
+
+THINKPAD_WMI_CREATE_AUTH_ATTR(password, "password", S_IRUSR|S_IWUSR);
+THINKPAD_WMI_CREATE_AUTH_ATTR(password_encoding, "password_encoding",
+			      S_IRUSR|S_IWUSR);
+THINKPAD_WMI_CREATE_AUTH_ATTR(password_kbdlang, "password_kbd_lang",
+			      S_IRUSR|S_IWUSR);
+THINKPAD_WMI_CREATE_AUTH_ATTR(password_type, "password_type", S_IRUSR|S_IWUSR);
+
+static ssize_t show_password_settings(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	struct thinkpad_wmi_pcfg pcfg;
+	ssize_t ret;
+
+	ret = thinkpad_wmi_password_settings(&pcfg);
+	if (ret)
+		return ret;
+	ret += sprintf(buf, "password_mode:       %#x\n", pcfg.password_mode);
+	ret += sprintf(buf + ret, "password_state:      %#x\n",
+		       pcfg.password_state);
+	ret += sprintf(buf + ret, "min_length:          %d\n", pcfg.min_length);
+	ret += sprintf(buf + ret, "max_length:          %d\n", pcfg.max_length);
+	ret += sprintf(buf + ret, "supported_encodings: %#x\n",
+		       pcfg.supported_encodings);
+	ret += sprintf(buf + ret, "supported_keyboard:  %#x\n",
+		       pcfg.supported_keyboard);
+	return ret;
+}
+
+static DEVICE_ATTR(password_settings, S_IRUSR, show_password_settings, NULL);
+
+static ssize_t store_password_change(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct thinkpad_wmi *thinkpad = dev_get_drvdata(dev);
+	size_t buffer_size;
+	char *buffer;
+	ssize_t ret;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	/* Format: 'PasswordType,CurrentPw,NewPw,Encoding,KbdLang;' */
+
+	/* auth_string is the size of CurrentPassword,Encoding,KbdLang */
+	buffer_size = (sizeof(thinkpad->password_type) + 1 + count + 1 +
+		       sizeof(thinkpad->auth_string) + 2);
+	buffer = kmalloc(buffer_size, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	strcpy(buffer, thinkpad->password_type);
+
+	if (*thinkpad->password) {
+		strcat(buffer, ",");
+		strcat(buffer, thinkpad->password);
+	}
+	strcat(buffer, ",");
+	strncat(buffer, buf, count);
+	if (count)
+		strim(buffer);
+
+	if (*thinkpad->password_encoding) {
+		strcat(buffer, ",");
+		strcat(buffer, thinkpad->password_encoding);
+	}
+	if (*thinkpad->password_kbdlang) {
+		strcat(buffer, ",");
+		strcat(buffer, thinkpad->password_kbdlang);
+	}
+	strcat(buffer, ";");
+
+	ret = thinkpad_wmi_set_bios_password(buffer);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static struct device_attribute dev_attr_password_change = {
+	.attr = {
+		.name = "password_change",
+		.mode = S_IWUSR },
+	.store  = store_password_change,
+};
+
+
+static ssize_t store_load_default(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct thinkpad_wmi *thinkpad = dev_get_drvdata(dev);
+
+	return thinkpad_wmi_load_default(thinkpad->auth_string);
+}
+
+static DEVICE_ATTR(load_default_settings, S_IWUSR, NULL, store_load_default);
+
+static struct attribute *platform_attributes[] = {
+	&dev_attr_password_settings.attr,
+	&dev_attr_password.attr,
+	&dev_attr_password_encoding.attr,
+	&dev_attr_password_kbdlang.attr,
+	&dev_attr_password_type.attr,
+	&dev_attr_password_change.attr,
+	&dev_attr_load_default_settings.attr,
+	NULL
+};
+
+static umode_t thinkpad_sysfs_is_visible(struct kobject *kobj,
+					 struct attribute *attr,
+					 int idx)
+{
+	bool supported = true;
+
+	return supported ? attr->mode : 0;
+}
+
+static struct attribute_group platform_attribute_group = {
+	.is_visible	= thinkpad_sysfs_is_visible,
+	.attrs		= platform_attributes
+};
+
+static void thinkpad_wmi_sysfs_exit(struct platform_device *device)
+{
+	struct thinkpad_wmi *thinkpad = platform_get_drvdata(device);
+	int i;
+
+	sysfs_remove_group(&device->dev.kobj, &platform_attribute_group);
+
+	if (!thinkpad->devattrs)
+		return;
+
+	for (i = 0; i < thinkpad->settings_count; ++i) {
+		struct dev_ext_attribute *deveattr = &thinkpad->devattrs[i];
+		struct device_attribute *devattr = &deveattr->attr;
+
+		if (devattr->attr.name)
+			device_remove_file(&device->dev, devattr);
+	}
+	kfree(thinkpad->devattrs);
+	thinkpad->devattrs = NULL;
+}
+
+static int __init thinkpad_wmi_sysfs_init(struct platform_device *device)
+{
+	struct thinkpad_wmi *thinkpad = platform_get_drvdata(device);
+	struct dev_ext_attribute *devattrs;
+	int count = thinkpad->settings_count;
+	int i, ret;
+
+	devattrs = kmalloc(sizeof(*devattrs) * count, GFP_KERNEL);
+	if (!devattrs)
+		return -ENOMEM;
+	thinkpad->devattrs = devattrs;
+
+	for (i = 0; i < count; ++i) {
+		struct dev_ext_attribute *deveattr = &devattrs[i];
+		struct device_attribute *devattr = &deveattr->attr;
+
+		sysfs_attr_init(&devattr->attr);
+		devattr->attr.name = thinkpad->settings[i];
+		devattr->attr.mode = S_IRUGO | S_IWUSR;
+		devattr->show = show_setting;
+		devattr->store = store_setting;
+		deveattr->var = (void *)(uintptr_t)i;
+		ret = device_create_file(&device->dev, devattr);
+		if (ret) {
+			/* Name is used to check is file has been created. */
+			devattr->attr.name = NULL;
+			return ret;
+		}
+	}
+
+	return sysfs_create_group(&device->dev.kobj, &platform_attribute_group);
+}
+
+/*
+ * Platform device
+ */
+static int __init thinkpad_wmi_platform_init(struct thinkpad_wmi *thinkpad)
+{
+	return thinkpad_wmi_sysfs_init(thinkpad->platform_device);
+}
+
+static void thinkpad_wmi_platform_exit(struct thinkpad_wmi *thinkpad)
+{
+	thinkpad_wmi_sysfs_exit(thinkpad->platform_device);
+}
+
+/* debugfs */
+
+static ssize_t dbgfs_write_argument(struct file *file,
+				    const char __user *userbuf,
+				    size_t count, loff_t *pos)
+{
+	struct thinkpad_wmi *thinkpad = file->f_path.dentry->d_inode->i_private;
+	char *kernbuf = thinkpad->debug.argument;
+	size_t size = sizeof(thinkpad->debug.argument);
+
+	if (count > PAGE_SIZE - 1)
+		return -EINVAL;
+
+	if (count > size - 1)
+		return -EINVAL;
+
+	if (copy_from_user(kernbuf, userbuf, count))
+		return -EFAULT;
+
+	kernbuf[count] = 0;
+
+	strim(kernbuf);
+
+	return count;
+}
+
+static int dbgfs_show_argument(struct seq_file *m, void *v)
+{
+	struct thinkpad_wmi *thinkpad = m->private;
+
+	seq_printf(m, "%s\n", thinkpad->debug.argument);
+	return 0;
+}
+
+static int thinkpad_wmi_debugfs_argument_open(struct inode *inode,
+					      struct file *file)
+{
+	struct thinkpad_wmi *thinkpad = inode->i_private;
+
+	return single_open(file, dbgfs_show_argument, thinkpad);
+}
+
+static const struct file_operations thinkpad_wmi_debugfs_argument_fops = {
+	.owner		= THIS_MODULE,
+	.open		= thinkpad_wmi_debugfs_argument_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.write		= dbgfs_write_argument,
+};
+
+struct thinkpad_wmi_debugfs_node {
+	struct thinkpad_wmi *thinkpad;
+	char *name;
+	int (*show)(struct seq_file *m, void *data);
+};
+
+static void show_bios_setting_line(struct thinkpad_wmi *thinkpad,
+				   struct seq_file *m, int i, bool list_valid)
+{
+	int ret;
+	char *settings = NULL, *choices = NULL, *p;
+
+	ret = thinkpad_wmi_bios_setting(i, &settings);
+	if (ret || !settings)
+		return;
+
+	p = strchr(settings, ',');
+	if (p)
+		*p = '=';
+	seq_printf(m, "%s", settings);
+
+
+	if (!thinkpad->can_get_bios_selections)
+		goto line_feed;
+
+	if (p)
+		*p = '\0';
+
+	ret = thinkpad_wmi_get_bios_selections(settings, &choices);
+	if (ret || !choices || !*choices)
+		goto line_feed;
+
+	seq_printf(m, "\t[%s]", choices);
+
+line_feed:
+	kfree(settings);
+	kfree(choices);
+	seq_puts(m, "\n");
+}
+
+static int dbgfs_bios_settings(struct seq_file *m, void *data)
+{
+	struct thinkpad_wmi *thinkpad = m->private;
+	int i;
+
+	for (i = 0; i < thinkpad->settings_count; ++i)
+		show_bios_setting_line(thinkpad, m, i, true);
+
+	return 0;
+}
+
+static int dbgfs_bios_setting(struct seq_file *m, void *data)
+{
+	struct thinkpad_wmi *thinkpad = m->private;
+
+	show_bios_setting_line(m->private, m, thinkpad->debug.instance, false);
+	return 0;
+}
+
+static int dbgfs_list_valid_choices(struct seq_file *m, void *data)
+{
+	struct thinkpad_wmi *thinkpad = m->private;
+	char *choices = NULL;
+	int ret;
+
+	ret = thinkpad_wmi_get_bios_selections(thinkpad->debug.argument,
+					      &choices);
+
+	if (ret || !choices || !*choices) {
+		kfree(choices);
+		return -EIO;
+	}
+
+	seq_printf(m, "%s\n", choices);
+	kfree(choices);
+	return 0;
+}
+
+static int dbgfs_set_bios_settings(struct seq_file *m, void *data)
+{
+	struct thinkpad_wmi *thinkpad = m->private;
+
+	return thinkpad_wmi_set_bios_settings(thinkpad->debug.argument);
+}
+
+static int dbgfs_save_bios_settings(struct seq_file *m, void *data)
+{
+	struct thinkpad_wmi *thinkpad = m->private;
+
+	return thinkpad_wmi_save_bios_settings(thinkpad->debug.argument);
+}
+
+static int dbgfs_discard_bios_settings(struct seq_file *m, void *data)
+{
+	struct thinkpad_wmi *thinkpad = m->private;
+
+	return thinkpad_wmi_discard_bios_settings(thinkpad->debug.argument);
+}
+
+static int dbgfs_load_default(struct seq_file *m, void *data)
+{
+	struct thinkpad_wmi *thinkpad = m->private;
+
+	return thinkpad_wmi_load_default(thinkpad->debug.argument);
+}
+
+static int dbgfs_set_bios_password(struct seq_file *m, void *data)
+{
+	struct thinkpad_wmi *thinkpad = m->private;
+
+	return thinkpad_wmi_set_bios_password(thinkpad->debug.argument);
+}
+
+static int dbgfs_bios_password_settings(struct seq_file *m, void *data)
+{
+	struct thinkpad_wmi_pcfg pcfg;
+	int ret;
+
+	ret = thinkpad_wmi_password_settings(&pcfg);
+	if (ret)
+		return ret;
+	seq_printf(m, "password_mode:       %#x\n", pcfg.password_mode);
+	seq_printf(m, "password_state:      %#x\n", pcfg.password_state);
+	seq_printf(m, "min_length:          %d\n", pcfg.min_length);
+	seq_printf(m, "max_length:          %d\n", pcfg.max_length);
+	seq_printf(m, "supported_encodings: %#x\n", pcfg.supported_encodings);
+	seq_printf(m, "supported_keyboard:  %#x\n", pcfg.supported_keyboard);
+	return 0;
+}
+
+static struct thinkpad_wmi_debugfs_node thinkpad_wmi_debug_files[] = {
+	{ NULL, "bios_settings", dbgfs_bios_settings },
+	{ NULL, "bios_setting", dbgfs_bios_setting },
+	{ NULL, "list_valid_choices", dbgfs_list_valid_choices },
+	{ NULL, "set_bios_settings", dbgfs_set_bios_settings },
+	{ NULL, "save_bios_settings", dbgfs_save_bios_settings },
+	{ NULL, "discard_bios_settings", dbgfs_discard_bios_settings },
+	{ NULL, "load_default", dbgfs_load_default },
+	{ NULL, "set_bios_password", dbgfs_set_bios_password },
+	{ NULL, "bios_password_settings", dbgfs_bios_password_settings },
+};
+
+static int thinkpad_wmi_debugfs_open(struct inode *inode, struct file *file)
+{
+	struct thinkpad_wmi_debugfs_node *node = inode->i_private;
+
+	return single_open(file, node->show, node->thinkpad);
+}
+
+static const struct file_operations thinkpad_wmi_debugfs_io_ops = {
+	.owner = THIS_MODULE,
+	.open  = thinkpad_wmi_debugfs_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static void __init thinkpad_wmi_debugfs_exit(struct thinkpad_wmi *thinkpad)
+{
+	debugfs_remove_recursive(thinkpad->debug.root);
+}
+
+static int thinkpad_wmi_debugfs_init(struct thinkpad_wmi *thinkpad)
+{
+	struct dentry *dent;
+	int i;
+
+	thinkpad->debug.instances_count = thinkpad->settings_count;
+
+	thinkpad->debug.root = debugfs_create_dir(THINKPAD_WMI_FILE, NULL);
+	if (!thinkpad->debug.root) {
+		pr_err("failed to create debugfs directory");
+		goto error_debugfs;
+	}
+
+	dent = debugfs_create_file("argument", S_IRUGO | S_IWUSR,
+				   thinkpad->debug.root, thinkpad,
+				   &thinkpad_wmi_debugfs_argument_fops);
+	if (!dent)
+		goto error_debugfs;
+
+	dent = debugfs_create_u8("instance", S_IRUGO | S_IWUSR,
+				 thinkpad->debug.root,
+				 &thinkpad->debug.instance);
+	if (!dent)
+		goto error_debugfs;
+
+	dent = debugfs_create_u8("instances_count", S_IRUGO,
+				 thinkpad->debug.root,
+				 &thinkpad->debug.instances_count);
+	if (!dent)
+		goto error_debugfs;
+
+	for (i = 0; i < ARRAY_SIZE(thinkpad_wmi_debug_files); i++) {
+		struct thinkpad_wmi_debugfs_node *node;
+
+		node = &thinkpad_wmi_debug_files[i];
+
+		/* Filter non-present interfaces */
+		if (!strcmp(node->name, "set_bios_settings") &&
+		    !thinkpad->can_set_bios_settings)
+			continue;
+		if (!strcmp(node->name, "dicard_bios_settings") &&
+		    !thinkpad->can_discard_bios_settings)
+			continue;
+		if (!strcmp(node->name, "load_default_settings") &&
+		    !thinkpad->can_load_default_settings)
+			continue;
+		if (!strcmp(node->name, "get_bios_selections") &&
+		    !thinkpad->can_get_bios_selections)
+			continue;
+		if (!strcmp(node->name, "set_bios_password") &&
+		    !thinkpad->can_set_bios_password)
+			continue;
+		if (!strcmp(node->name, "bios_password_settings") &&
+		    !thinkpad->can_get_password_settings)
+			continue;
+
+		node->thinkpad = thinkpad;
+		dent = debugfs_create_file(node->name, S_IFREG | S_IRUGO,
+					   thinkpad->debug.root, node,
+					   &thinkpad_wmi_debugfs_io_ops);
+		if (!dent) {
+			pr_err("failed to create debug file: %s\n", node->name);
+			goto error_debugfs;
+		}
+	}
+
+
+	return 0;
+
+error_debugfs:
+	thinkpad_wmi_debugfs_exit(thinkpad);
+	return -ENOMEM;
+}
+
+/* Base driver */
+static void __init thinkpad_wmi_analyze(struct thinkpad_wmi *thinkpad)
+{
+	acpi_status status;
+	int i = 0;
+
+	/* Try to find the number of valid settings of this machine
+	 * and use it to create sysfs attributes */
+	for (i = 0; i < 0xFF; ++i) {
+		char *item = NULL;
+		char *p;
+
+		status = thinkpad_wmi_bios_setting(i, &item);
+		if (ACPI_FAILURE(status))
+			break;
+		if (!item || !*item)
+			break;
+		/* Remove the value part */
+		p = strchr(item, ',');
+		if (p)
+			*p = '\0';
+		thinkpad->settings[i] = item; /* Cache setting name */
+	}
+
+	thinkpad->settings_count = i;
+	pr_info("Found %d settings", thinkpad->settings_count);
+
+	if (wmi_has_guid(LENOVO_SET_BIOS_SETTINGS_GUID) &&
+	    wmi_has_guid(LENOVO_SAVE_BIOS_SETTINGS_GUID)) {
+		thinkpad->can_set_bios_settings = true;
+	}
+
+	if (wmi_has_guid(LENOVO_DISCARD_BIOS_SETTINGS_GUID))
+		thinkpad->can_discard_bios_settings = true;
+
+	if (wmi_has_guid(LENOVO_LOAD_DEFAULT_SETTINGS_GUID))
+		thinkpad->can_load_default_settings = true;
+
+	if (wmi_has_guid(LENOVO_GET_BIOS_SELECTIONS_GUID))
+		thinkpad->can_get_bios_selections = true;
+
+	if (wmi_has_guid(LENOVO_SET_BIOS_PASSWORD_GUID))
+		thinkpad->can_set_bios_password = true;
+
+	if (wmi_has_guid(LENOVO_BIOS_PASSWORD_SETTINGS_GUID))
+		thinkpad->can_get_password_settings = true;
+}
+
+static int __init thinkpad_wmi_add(struct platform_device *pdev)
+{
+	struct thinkpad_wmi *thinkpad;
+	int err;
+
+	thinkpad = kzalloc(sizeof(struct thinkpad_wmi), GFP_KERNEL);
+	if (!thinkpad)
+		return -ENOMEM;
+
+	thinkpad->platform_device = pdev;
+	platform_set_drvdata(thinkpad->platform_device, thinkpad);
+
+	thinkpad_wmi_analyze(thinkpad);
+
+	err = thinkpad_wmi_platform_init(thinkpad);
+	if (err)
+		goto error_platform;
+
+	err = thinkpad_wmi_debugfs_init(thinkpad);
+	if (err)
+		goto error_debugfs;
+
+	return 0;
+
+error_debugfs:
+	thinkpad_wmi_platform_exit(thinkpad);
+error_platform:
+	kfree(thinkpad);
+	return err;
+}
+
+static int __exit thinkpad_wmi_remove(struct platform_device *device)
+{
+	struct thinkpad_wmi *thinkpad;
+	int i;
+
+	thinkpad = platform_get_drvdata(device);
+	thinkpad_wmi_debugfs_exit(thinkpad);
+	thinkpad_wmi_platform_exit(thinkpad);
+
+	for (i = 0; thinkpad->settings[i]; ++i) {
+		kfree(thinkpad->settings[i]);
+		thinkpad->settings[i] = NULL;
+	}
+
+	kfree(thinkpad);
+	return 0;
+}
+
+static struct platform_device *platform_device;
+
+static int __init thinkpad_wmi_probe(struct platform_device *pdev)
+{
+	if (!wmi_has_guid(LENOVO_BIOS_SETTING_GUID)) {
+		pr_warn("Lenovo_BiosSetting GUID missing\n");
+		return -ENODEV;
+	}
+
+	return thinkpad_wmi_add(pdev);
+}
+
+static struct platform_driver platform_driver = {
+	.remove = __exit_p(thinkpad_wmi_remove),
+	.driver = {
+		.name = THINKPAD_WMI_FILE,
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init thinkpad_wmi_init(void)
+{
+	platform_device = platform_create_bundle(&platform_driver,
+						 thinkpad_wmi_probe,
+						 NULL, 0, NULL, 0);
+	if (IS_ERR(platform_device))
+		return PTR_ERR(platform_device);
+	return 0;
+}
+
+static void __exit thinkpad_wmi_exit(void)
+{
+	platform_device_unregister(platform_device);
+	platform_driver_unregister(&platform_driver);
+}
+
+module_init(thinkpad_wmi_init);
+module_exit(thinkpad_wmi_exit);
-- 
2.11.0