new file mode 100644
@@ -0,0 +1,126 @@
+What: /sys/bus/platform/devices/GGL0001:*/BINF.2
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows information about the current boot of
+ the active EC firmware.
+ * 0 - Read only (recovery) firmware.
+ * 1 - Rewritable firmware.
+
+What: /sys/bus/platform/devices/GGL0001:*/BINF.3
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows information about the current boot of
+ the active main firmware type.
+ * 0 - Recovery.
+ * 1 - Normal.
+ * 2 - Developer.
+ * 3 - Netboot (factory installation only).
+
+What: /sys/bus/platform/devices/GGL0001:*/CHSW
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows the switch position for the Chrome OS specific
+ hardware switches.
+ * 0 - No changes.
+ * 2 - Recovery button was pressed when firmware booted.
+ * 4 - Recovery button was pressed when EC firmware booted.
+ * 32 - Developer switch was enabled when firmware booted.
+ * 512 - Firmware write protection was disabled when firmware
+ booted.
+
+What: /sys/bus/platform/devices/GGL0001:*/FMAP
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows the physical memory address of the start of
+ the main processor firmware flashmap.
+
+What: /sys/bus/platform/devices/GGL0001:*/FRID
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows the firmware version for the read-only portion
+ of the main processor firmware.
+
+What: /sys/bus/platform/devices/GGL0001:*/FWID
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows the firmware version for the rewritable portion
+ of the main processor firmware.
+
+What: /sys/bus/platform/devices/GGL0001:*/GPIO.X/GPIO.0
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows the type of the GPIO signal for the Chrome OS
+ specific GPIO assignments.
+ * 1 - Recovery button.
+ * 2 - Developer mode switch.
+ * 3 - Firmware write protection switch.
+ * 256 to 511 - Debug header GPIO 0 to GPIO 255.
+
+What: /sys/bus/platform/devices/GGL0001:*/GPIO.X/GPIO.1
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows the signal attributes of the GPIO signal.
+ * 0 - Signal is active low.
+ * 1 - Signal is active high.
+
+What: /sys/bus/platform/devices/GGL0001:*/GPIO.X/GPIO.2
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows the GPIO number on the specified GPIO
+ controller.
+
+What: /sys/bus/platform/devices/GGL0001:*/GPIO.X/GPIO.3
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows the name of the GPIO controller.
+
+What: /sys/bus/platform/devices/GGL0001:*/HWID
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows the hardware ID for the Chromebook.
+
+What: /sys/bus/platform/devices/GGL0001:*/MECK
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This binary file returns the SHA-1 or SHA-256 hash that is
+ read out of the Management Engine extended registers during
+ boot. The hash is exported vi ACPI so the OS can verify that
+ the Management Engine firmware has not changed. If Management
+ Engine is not present, or if the firmware was unable to read the
+ extended registers, this buffer size can be zero.
+
+What: /sys/bus/platform/devices/GGL0001:*/VBNV.0
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows the offset in CMOS bank 0 of the verified boot
+ non-volatile storage block, counting from the first writable
+ CMOS byte (that is, 'offset = 0' is the byte following the 14
+ bytes of clock data).
+
+What: /sys/bus/platform/devices/GGL0001:*/VBNV.1
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This file shows the size in bytes of the verified boot
+ non-volatile storage block.
+
+What: /sys/bus/platform/devices/GGL0001:*/VDAT
+Date: May 2022
+KernelVersion: 5.19
+Description:
+ This binary file returns the verified boot data block shared
+ between the firmware verification step and the kernel
+ verification step.
new file mode 100644
@@ -0,0 +1,363 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================
+Chrome OS ACPI Device
+=====================
+
+Hardware functionality specific to Chrome OS is exposed through a Chrome OS ACPI device.
+The plug and play ID of a Chrome OS ACPI device is GGL0001. GGL is a valid PNP ID of Google.
+PNP ID can be used with the ACPI devices according to the guidelines. The following ACPI
+objects are supported:
+
+.. flat-table:: Supported ACPI Objects
+ :widths: 1 2
+ :header-rows: 1
+
+ * - Object
+ - Description
+
+ * - CHSW
+ - Chrome OS switch positions
+
+ * - HWID
+ - Chrome OS hardware ID
+
+ * - FWID
+ - Chrome OS firmware version
+
+ * - FRID
+ - Chrome OS read-only firmware version
+
+ * - BINF
+ - Chrome OS boot information
+
+ * - GPIO
+ - Chrome OS GPIO assignments
+
+ * - VBNV
+ - Chrome OS NVRAM locations
+
+ * - VDTA
+ - Chrome OS verified boot data
+
+ * - FMAP
+ - Chrome OS flashmap base address
+
+ * - MLST
+ - Chrome OS method list
+
+CHSW (Chrome OS switch positions)
+=================================
+This control method returns the switch positions for Chrome OS specific hardware switches.
+
+Arguments:
+----------
+None
+
+Result code:
+------------
+An integer containing the switch positions as bitfields:
+
+.. flat-table::
+ :widths: 1 2
+
+ * - 0x00000002
+ - Recovery button was pressed when x86 firmware booted.
+
+ * - 0x00000004
+ - Recovery button was pressed when EC firmware booted. (required if EC EEPROM is
+ rewritable; otherwise optional)
+
+ * - 0x00000020
+ - Developer switch was enabled when x86 firmware booted.
+
+ * - 0x00000200
+ - Firmware write protection was disabled when x86 firmware booted. (required if
+ firmware write protection is controlled through x86 BIOS; otherwise optional)
+
+All other bits are reserved and should be set to 0.
+
+HWID (Chrome OS hardware ID)
+============================
+This control method returns the hardware ID for the Chromebook.
+
+Arguments:
+----------
+None
+
+Result code:
+------------
+A null-terminated ASCII string containing the hardware ID from the Model-Specific Data area of
+EEPROM.
+
+Note that the hardware ID can be up to 256 characters long, including the terminating null.
+
+FWID (Chrome OS firmware version)
+=================================
+This control method returns the firmware version for the rewritable portion of the main
+processor firmware.
+
+Arguments:
+----------
+None
+
+Result code:
+------------
+A null-terminated ASCII string containing the complete firmware version for the rewritable
+portion of the main processor firmware.
+
+FRID (Chrome OS read-only firmware version)
+===========================================
+This control method returns the firmware version for the read-only portion of the main
+processor firmware.
+
+Arguments:
+----------
+None
+
+Result code:
+------------
+A null-terminated ASCII string containing the complete firmware version for the read-only
+(bootstrap + recovery ) portion of the main processor firmware.
+
+BINF (Chrome OS boot information)
+=================================
+This control method returns information about the current boot.
+
+Arguments:
+----------
+None
+
+Result code:
+------------
+
+.. code-block::
+
+ Package {
+ Reserved1
+ Reserved2
+ Active EC Firmware
+ Active Main Firmware Type
+ Reserved5
+ }
+
+.. flat-table::
+ :widths: 1 1 2
+ :header-rows: 1
+
+ * - Field
+ - Format
+ - Description
+
+ * - Reserved1
+ - DWORD
+ - Set to 256 (0x100). This indicates this field is no longer used.
+
+ * - Reserved2
+ - DWORD
+ - Set to 256 (0x100). This indicates this field is no longer used.
+
+ * - Active EC firmware
+ - DWORD
+ - The EC firmware which was used during boot.
+
+ - 0 - Read-only (recovery) firmware
+ - 1 - Rewritable firmware.
+
+ Set to 0 if EC firmware is always read-only.
+
+ * - Active Main Firmware Type
+ - DWORD
+ - The main firmware type which was used during boot.
+
+ - 0 - Recovery
+ - 1 - Normal
+ - 2 - Developer
+ - 3 - netboot (factory installation only)
+
+ Other values are reserved.
+
+ * - Reserved5
+ - DWORD
+ - Set to 256 (0x100). This indicates this field is no longer used.
+
+GPIO (Chrome OS GPIO assignments)
+=================================
+This control method returns information about Chrome OS specific GPIO assignments for
+Chrome OS hardware, so the kernel can directly control that hardware.
+
+Arguments:
+----------
+None
+
+Result code:
+------------
+.. code-block::
+
+ Package {
+ Package {
+ // First GPIO assignment
+ Signal Type //DWORD
+ Attributes //DWORD
+ Controller Offset //DWORD
+ Controller Name //ASCIIZ
+ },
+ ...
+ Package {
+ // Last GPIO assignment
+ Signal Type //DWORD
+ Attributes //DWORD
+ Controller Offset //DWORD
+ Controller Name //ASCIIZ
+ }
+ }
+
+Where ASCIIZ means a null-terminated ASCII string.
+
+.. flat-table::
+ :widths: 1 1 2
+ :header-rows: 1
+
+ * - Field
+ - Format
+ - Description
+
+ * - Signal Type
+ - DWORD
+ - Type of GPIO signal
+
+ - 0x00000001 - Recovery button
+ - 0x00000002 - Developer mode switch
+ - 0x00000003 - Firmware write protection switch
+ - 0x00000100 - Debug header GPIO 0
+ - ...
+ - 0x000001FF - Debug header GPIO 255
+
+ Other values are reserved.
+
+ * - Attributes
+ - DWORD
+ - Signal attributes as bitfields:
+
+ - 0x00000001 - Signal is active-high (for button, a GPIO value
+ of 1 means the button is pressed; for switches, a GPIO value
+ of 1 means the switch is enabled). If this bit is 0, the signal
+ is active low. Set to 0 for debug header GPIOs.
+
+ * - Controller Offset
+ - DWORD
+ - GPIO number on the specified controller.
+
+ * - Controller Name
+ - ASCIIZ
+ - Name of the controller for the GPIO.
+ Currently supported names:
+ "NM10" - Intel NM10 chip
+
+VBNV (Chrome OS NVRAM locations)
+================================
+This control method returns information about the NVRAM (CMOS) locations used to
+communicate with the BIOS.
+
+Arguments:
+----------
+None
+
+Result code:
+------------
+.. code-block::
+
+ Package {
+ NV Storage Block Offset //DWORD
+ NV Storage Block Size //DWORD
+ }
+
+.. flat-table::
+ :widths: 1 1 2
+ :header-rows: 1
+
+ * - Field
+ - Format
+ - Description
+
+ * - NV Storage Block Offset
+ - DWORD
+ - Offset in CMOS bank 0 of the verified boot non-volatile storage block, counting from
+ the first writable CMOS byte (that is, offset=0 is the byte following the 14 bytes of
+ clock data).
+
+ * - NV Storage Block Size
+ - DWORD
+ - Size in bytes of the verified boot non-volatile storage block.
+
+FMAP (Chrome OS flashmap address)
+=================================
+This control method returns the physical memory address of the start of the main processor
+firmware flashmap.
+
+Arguments:
+----------
+None
+
+NoneResult code:
+----------------
+A DWORD containing the physical memory address of the start of the main processor firmware
+flashmap.
+
+VDTA (Chrome OS verified boot data)
+===================================
+This control method returns the verified boot data block shared between the firmware
+verification step and the kernel verification step.
+
+Arguments:
+----------
+None
+
+Result code:
+------------
+A buffer containing the verified boot data block.
+
+MECK (Management Engine Checksum)
+=================================
+This control method returns the SHA-1 or SHA-256 hash that is read out of the Management
+Engine extended registers during boot. The hash is exported via ACPI so the OS can verify that
+the ME firmware has not changed. If Management Engine is not present, or if the firmware was
+unable to read the extended registers, this buffer can be zero.
+
+Arguments:
+----------
+None
+
+Result code:
+------------
+A buffer containing the ME hash.
+
+MLST (Chrome OS method list)
+============================
+This control method returns a list of the other control methods supported by the Chrome OS
+hardware device.
+
+Arguments:
+----------
+None
+
+Result code:
+------------
+A package containing a list of null-terminated ASCII strings, one for each control method
+supported by the Chrome OS hardware device, not including the MLST method itself.
+For this version of the specification, the result is:
+
+.. code-block::
+
+ Package {
+ "CHSW",
+ "FWID",
+ "HWID",
+ "FRID",
+ "BINF",
+ "GPIO",
+ "VBNV",
+ "FMAP",
+ "VDTA",
+ "MECK"
+ }
@@ -29,3 +29,4 @@ ACPI Support
non-d0-probe
extcon-intel-int3496
intel-pmc-mux
+ chromeos-acpi-device
@@ -15,6 +15,17 @@ menuconfig CHROME_PLATFORMS
if CHROME_PLATFORMS
+config CHROMEOS_ACPI
+ tristate "ChromeOS specific ACPI extensions"
+ depends on ACPI
+ help
+ This driver provides the firmware interface for the services
+ exported through the ChromeOS interfaces when using ChromeOS
+ ACPI firmware.
+
+ If you have an ACPI-compatible Chromebook, say Y or M here.
+ The module will be called chromeos_acpi.
+
config CHROMEOS_LAPTOP
tristate "Chrome OS Laptop"
depends on I2C && DMI && X86
@@ -4,6 +4,7 @@
CFLAGS_cros_ec_trace.o:= -I$(src)
CFLAGS_cros_ec_sensorhub_ring.o:= -I$(src)
+obj-$(CONFIG_CHROMEOS_ACPI) += chromeos_acpi.o
obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o
obj-$(CONFIG_CHROMEOS_PRIVACY_SCREEN) += chromeos_privacy_screen.o
obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o
new file mode 100644
@@ -0,0 +1,257 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ChromeOS specific ACPI extensions
+ *
+ * Copyright 2022 Google LLC
+ *
+ * This driver attaches to the ChromeOS ACPI device and then exports the
+ * values reported by the ACPI in a sysfs directory. All values are
+ * presented in the string form (numbers as decimal values) and can be
+ * accessed as the contents of the appropriate read only files in the
+ * sysfs directory tree.
+ */
+#include <linux/acpi.h>
+#include <linux/platform_device.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+
+#define ACPI_ATTR_NAME_LEN 4
+
+#define DEV_ATTR(_var, _name) \
+ static struct device_attribute dev_attr_##_var = \
+ __ATTR(_name, 0444, chromeos_first_level_attr_show, NULL);
+
+#define GPIO_ATTR_GROUP(_group, _name, _num) \
+ static umode_t attr_is_visible_gpio_##_num(struct kobject *kobj, \
+ struct attribute *attr, int n) \
+ { \
+ if (_num < chromeos_acpi_gpio_groups) \
+ return attr->mode; \
+ return 0; \
+ } \
+ static ssize_t chromeos_attr_show_gpio_##_num(struct device *dev, \
+ struct device_attribute *attr, \
+ char *buf) \
+ { \
+ char name[ACPI_ATTR_NAME_LEN + 1]; \
+ int ret, num; \
+ \
+ ret = parse_attr_name(attr->attr.name, name, &num); \
+ if (ret) \
+ return ret; \
+ return chromeos_acpi_evaluate_method(dev, _num, num, name, buf); \
+ } \
+ static struct device_attribute dev_attr_0_##_group = \
+ __ATTR(GPIO.0, 0444, chromeos_attr_show_gpio_##_num, NULL); \
+ static struct device_attribute dev_attr_1_##_group = \
+ __ATTR(GPIO.1, 0444, chromeos_attr_show_gpio_##_num, NULL); \
+ static struct device_attribute dev_attr_2_##_group = \
+ __ATTR(GPIO.2, 0444, chromeos_attr_show_gpio_##_num, NULL); \
+ static struct device_attribute dev_attr_3_##_group = \
+ __ATTR(GPIO.3, 0444, chromeos_attr_show_gpio_##_num, NULL); \
+ \
+ static struct attribute *attrs_##_group[] = { \
+ &dev_attr_0_##_group.attr, \
+ &dev_attr_1_##_group.attr, \
+ &dev_attr_2_##_group.attr, \
+ &dev_attr_3_##_group.attr, \
+ NULL \
+ }; \
+ static const struct attribute_group attr_group_##_group = { \
+ .name = _name, \
+ .is_visible = attr_is_visible_gpio_##_num, \
+ .attrs = attrs_##_group, \
+ };
+
+static unsigned int chromeos_acpi_gpio_groups;
+
+/* Parse the ACPI package and return the data related to that attribute */
+static int chromeos_acpi_handle_package(struct device *dev, union acpi_object *obj,
+ int pkg_num, int sub_pkg_num, char *name, char *buf)
+{
+ union acpi_object *element = obj->package.elements;
+
+ if (pkg_num >= obj->package.count)
+ return -EINVAL;
+ element += pkg_num;
+
+ if (element->type == ACPI_TYPE_PACKAGE) {
+ if (sub_pkg_num >= element->package.count)
+ return -EINVAL;
+ /* select sub element inside this package */
+ element = element->package.elements;
+ element += sub_pkg_num;
+ }
+
+ switch (element->type) {
+ case ACPI_TYPE_INTEGER:
+ return sysfs_emit(buf, "%d\n", (int)element->integer.value);
+ case ACPI_TYPE_STRING:
+ return sysfs_emit(buf, "%s\n", element->string.pointer);
+ case ACPI_TYPE_BUFFER:
+ return sysfs_emit(buf, "%s\n", element->buffer.pointer);
+ default:
+ dev_err(dev, "element type %d not supported\n", element->type);
+ return -EINVAL;
+ }
+}
+
+static int chromeos_acpi_evaluate_method(struct device *dev, int pkg_num, int sub_pkg_num,
+ char *name, char *buf)
+{
+ struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+ acpi_status status;
+ int ret = -EINVAL;
+
+ status = acpi_evaluate_object(ACPI_HANDLE(dev), name, NULL, &output);
+ if (ACPI_FAILURE(status)) {
+ dev_err(dev, "failed to retrieve %s. %s\n", name, acpi_format_exception(status));
+ return ret;
+ }
+
+ if (((union acpi_object *)output.pointer)->type == ACPI_TYPE_PACKAGE)
+ ret = chromeos_acpi_handle_package(dev, output.pointer, pkg_num, sub_pkg_num,
+ name, buf);
+
+ kfree(output.pointer);
+ return ret;
+}
+
+static int parse_attr_name(const char *name, char *attr_name, int *attr_num)
+{
+ int ret;
+
+ ret = strscpy(attr_name, name, ACPI_ATTR_NAME_LEN + 1);
+ if (ret == -E2BIG)
+ return kstrtoint(&name[ACPI_ATTR_NAME_LEN + 1], 0, attr_num);
+ return 0;
+}
+
+static ssize_t chromeos_first_level_attr_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ char attr_name[ACPI_ATTR_NAME_LEN + 1];
+ int ret, attr_num = 0;
+
+ ret = parse_attr_name(attr->attr.name, attr_name, &attr_num);
+ if (ret)
+ return ret;
+ return chromeos_acpi_evaluate_method(dev, attr_num, 0, attr_name, buf);
+}
+
+static unsigned int get_gpio_pkg_num(struct device *dev)
+{
+ struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object *obj;
+ acpi_status status;
+ unsigned int count = 0;
+ char *name = "GPIO";
+
+ status = acpi_evaluate_object(ACPI_HANDLE(dev), name, NULL, &output);
+ if (ACPI_FAILURE(status)) {
+ dev_err(dev, "failed to retrieve %s. %s\n", name, acpi_format_exception(status));
+ return count;
+ }
+
+ obj = output.pointer;
+
+ if (obj->type == ACPI_TYPE_PACKAGE)
+ count = obj->package.count;
+
+ kfree(output.pointer);
+ return count;
+}
+
+DEV_ATTR(binf2, BINF.2)
+DEV_ATTR(binf3, BINF.3)
+DEV_ATTR(chsw, CHSW)
+DEV_ATTR(fmap, FMAP)
+DEV_ATTR(frid, FRID)
+DEV_ATTR(fwid, FWID)
+DEV_ATTR(hwid, HWID)
+DEV_ATTR(meck, MECK)
+DEV_ATTR(vbnv0, VBNV.0)
+DEV_ATTR(vbnv1, VBNV.1)
+DEV_ATTR(vdat, VDAT)
+
+static struct attribute *first_level_attrs[] = {
+ &dev_attr_binf2.attr,
+ &dev_attr_binf3.attr,
+ &dev_attr_chsw.attr,
+ &dev_attr_fmap.attr,
+ &dev_attr_frid.attr,
+ &dev_attr_fwid.attr,
+ &dev_attr_hwid.attr,
+ &dev_attr_meck.attr,
+ &dev_attr_vbnv0.attr,
+ &dev_attr_vbnv1.attr,
+ &dev_attr_vdat.attr,
+ NULL
+};
+
+static const struct attribute_group first_level_attr_group = {
+ .attrs = first_level_attrs,
+};
+
+/*
+ * Every platform can have a different number of GPIO attribute groups.
+ * Define upper limit groups. At run time, the platform decides to show
+ * the present number of groups only, others are hidden.
+ */
+GPIO_ATTR_GROUP(gpio0, "GPIO.0", 0)
+GPIO_ATTR_GROUP(gpio1, "GPIO.1", 1)
+GPIO_ATTR_GROUP(gpio2, "GPIO.2", 2)
+GPIO_ATTR_GROUP(gpio3, "GPIO.3", 3)
+GPIO_ATTR_GROUP(gpio4, "GPIO.4", 4)
+GPIO_ATTR_GROUP(gpio5, "GPIO.5", 5)
+GPIO_ATTR_GROUP(gpio6, "GPIO.6", 6)
+GPIO_ATTR_GROUP(gpio7, "GPIO.7", 7)
+
+static const struct attribute_group *chromeos_acpi_all_groups[] = {
+ &first_level_attr_group,
+ &attr_group_gpio0,
+ &attr_group_gpio1,
+ &attr_group_gpio2,
+ &attr_group_gpio3,
+ &attr_group_gpio4,
+ &attr_group_gpio5,
+ &attr_group_gpio6,
+ &attr_group_gpio7,
+ NULL
+};
+
+static int chromeos_acpi_device_probe(struct platform_device *pdev)
+{
+ chromeos_acpi_gpio_groups = get_gpio_pkg_num(&pdev->dev);
+
+ /*
+ * If the platform has more GPIO attribute groups than the number of
+ * groups this driver supports, give out a warning message.
+ */
+ if (chromeos_acpi_gpio_groups > ARRAY_SIZE(chromeos_acpi_all_groups) - 2)
+ dev_warn(&pdev->dev, "Only %zu GPIO attr groups supported by the driver out of total %u.\n",
+ ARRAY_SIZE(chromeos_acpi_all_groups) - 2, chromeos_acpi_gpio_groups);
+ return 0;
+}
+
+/* GGL is valid PNP ID of Google. PNP ID can be used with the ACPI devices. */
+static const struct acpi_device_id chromeos_device_ids[] = {
+ { "GGL0001", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(acpi, chromeos_device_ids);
+
+static struct platform_driver chromeos_acpi_device_driver = {
+ .probe = chromeos_acpi_device_probe,
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .dev_groups = chromeos_acpi_all_groups,
+ .acpi_match_table = chromeos_device_ids,
+ }
+};
+module_platform_driver(chromeos_acpi_device_driver);
+
+MODULE_AUTHOR("Muhammad Usama Anjum <usama.anjum@collabora.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ChromeOS specific ACPI extensions");