Merge tag 'tag-chrome-platform-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux

Pull chrome platform updates from Tzung-Bi Shih:
 "cros_ec:
   - Fix wrong error handling path
   - Clean-up patches

  cros_ec_chardev:
   - Re-introduce cros_ec_cmd_xfer to fix ABI broken

  cros_ec_lpcs:
   - Support the Framework Laptop

  cros_ec_typec:
   - Fix NULL dereference

  chromeos_acpi:
   - Add ChromeOS ACPI device driver
   - Fix Sphinx errors when `make htmldocs`

  misc:
   - Drop BUG_ON()s"

* tag 'tag-chrome-platform-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux:
  platform/chrome: Use imperative mood for ChromeOS ACPI sysfs ABI descriptions
  platform/chrome: Use tables for values lists of ChromeOS ACPI sysfs ABI
  platform/chrome: cros_ec_spi: drop BUG_ON() if `din` isn't large enough
  platform/chrome: cros_ec_spi: drop unneeded BUG_ON()
  platform/chrome: cros_ec_i2c: drop BUG_ON() in cros_ec_pkt_xfer_i2c()
  platform/chrome: cros_ec_proto: drop BUG_ON() in cros_ec_get_host_event()
  platform/chrome: cros_ec_proto: drop BUG_ON() in cros_ec_prepare_tx()
  platform/chrome: correct cros_ec_prepare_tx() usage
  platform/chrome: cros_ec_proto: drop unneeded BUG_ON() in prepare_packet()
  platform/chrome: Add ChromeOS ACPI device driver
  platform/chrome: cros_ec_typec: Check for EC driver
  platform/chrome: cros_ec_lpcs: reserve the MEC LPC I/O ports first
  platform/chrome: cros_ec_lpcs: detect the Framework Laptop
  platform/chrome: Re-introduce cros_ec_cmd_xfer and use it for ioctls
  platform/chrome: cros_ec: append newline to all logs
  platform/chrome: cros_ec: sort header inclusion alphabetically
  platform/chrome: cros_ec: determine `wake_enabled` in cros_ec_suspend()
  platform/chrome: cros_ec: remove unused variable `was_wake_device`
  platform/chrome: cros_ec: fix error handling in cros_ec_register()

17 files changed, 914 insertions, 58 deletions

diff --git a/Documentation/ABI/testing/sysfs-driver-chromeos-acpi b/Documentation/ABI/testing/sysfs-driver-chromeos-acpi
new file mode 100644
index 000000000000..c308926e1568
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-chromeos-acpi
@@ -0,0 +1,137 @@
+What:		/sys/bus/platform/devices/GGL0001:*/BINF.2
+Date:		May 2022
+KernelVersion:	5.19
+Description:
+		Returns active EC firmware of current boot (boolean).
+
+		== ===============================
+		0  Read only (recovery) firmware.
+		1  Rewritable firmware.
+		== ===============================
+
+What:		/sys/bus/platform/devices/GGL0001:*/BINF.3
+Date:		May 2022
+KernelVersion:	5.19
+Description:
+		Returns main firmware type for current boot (integer).
+
+		== =====================================
+		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:
+		Returns switch position for Chrome OS specific hardware
+		switches when the firmware is booted (integer).
+
+		==== ===========================================
+		0    No changes.
+		2    Recovery button was pressed.
+		4    Recovery button was pressed (EC firmware).
+		32   Developer switch was enabled.
+		512  Firmware write protection was disabled.
+		==== ===========================================
+
+What:		/sys/bus/platform/devices/GGL0001:*/FMAP
+Date:		May 2022
+KernelVersion:	5.19
+Description:
+		Returns 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:
+		Returns 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:
+		Returns 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:
+		Returns type of the GPIO signal for the Chrome OS specific
+		GPIO assignments (integer).
+
+		=========== ==================================
+		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:
+		Returns signal attributes of the GPIO signal (integer bitfield).
+
+		== =======================
+		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:
+		Returns 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:
+		Returns name of the GPIO controller.
+
+What:		/sys/bus/platform/devices/GGL0001:*/HWID
+Date:		May 2022
+KernelVersion:	5.19
+Description:
+		Returns hardware ID for the Chromebook.
+
+What:		/sys/bus/platform/devices/GGL0001:*/MECK
+Date:		May 2022
+KernelVersion:	5.19
+Description:
+		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 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:
+		Returns 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:
+		Return 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:
+		Returns the verified boot data block shared between the
+		firmware verification step and the kernel verification step
+		(binary).
diff --git a/Documentation/firmware-guide/acpi/chromeos-acpi-device.rst b/Documentation/firmware-guide/acpi/chromeos-acpi-device.rst
new file mode 100644
index 000000000000..f37fc90ce340
--- /dev/null
+++ b/Documentation/firmware-guide/acpi/chromeos-acpi-device.rst
@@ -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"
+        }
diff --git a/Documentation/firmware-guide/acpi/index.rst b/Documentation/firmware-guide/acpi/index.rst
index b053b0c3d696..b6a42f4ffe03 100644
--- a/Documentation/firmware-guide/acpi/index.rst
+++ b/Documentation/firmware-guide/acpi/index.rst
@@ -29,3 +29,4 @@ ACPI Support
    non-d0-probe
    extcon-intel-int3496
    intel-pmc-mux
+   chromeos-acpi-device
diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
index 75e93efd669f..717299cbccac 100644
--- a/drivers/platform/chrome/Kconfig
+++ b/drivers/platform/chrome/Kconfig
@@ -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
diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index 6420ca129548..52f5a2dde8b8 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -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
diff --git a/drivers/platform/chrome/chromeos_acpi.c b/drivers/platform/chrome/chromeos_acpi.c
new file mode 100644
index 000000000000..50d8a4d4352d
--- /dev/null
+++ b/drivers/platform/chrome/chromeos_acpi.c
@@ -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");
diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
index d49a4efe46c8..b3e94cdf7d1a 100644
--- a/drivers/platform/chrome/cros_ec.c
+++ b/drivers/platform/chrome/cros_ec.c
@@ -9,12 +9,12 @@
  * battery charging and regulator control, firmware update.
  */
 
-#include <linux/of_platform.h>
 #include <linux/interrupt.h>
-#include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/of_platform.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
+#include <linux/slab.h>
 #include <linux/suspend.h>
 
 #include "cros_ec.h"
@@ -189,6 +189,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 	ec_dev->max_request = sizeof(struct ec_params_hello);
 	ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
 	ec_dev->max_passthru = 0;
+	ec_dev->ec = NULL;
+	ec_dev->pd = NULL;
 
 	ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
 	if (!ec_dev->din)
@@ -213,7 +215,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 						"chromeos-ec", ec_dev);
 		if (err) {
-			dev_err(dev, "Failed to request IRQ %d: %d",
+			dev_err(dev, "Failed to request IRQ %d: %d\n",
 				ec_dev->irq, err);
 			return err;
 		}
@@ -245,18 +247,16 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 		if (IS_ERR(ec_dev->pd)) {
 			dev_err(ec_dev->dev,
 				"Failed to create CrOS PD platform device\n");
-			platform_device_unregister(ec_dev->ec);
-			return PTR_ERR(ec_dev->pd);
+			err = PTR_ERR(ec_dev->pd);
+			goto exit;
 		}
 	}
 
 	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
 		err = devm_of_platform_populate(dev);
 		if (err) {
-			platform_device_unregister(ec_dev->pd);
-			platform_device_unregister(ec_dev->ec);
 			dev_err(dev, "Failed to register sub-devices\n");
-			return err;
+			goto exit;
 		}
 	}
 
@@ -266,7 +266,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 	 */
 	err = cros_ec_sleep_event(ec_dev, 0);
 	if (err < 0)
-		dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec",
+		dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec\n",
 			err);
 
 	if (ec_dev->mkbp_event_supported) {
@@ -278,7 +278,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 		err = blocking_notifier_chain_register(&ec_dev->event_notifier,
 						      &ec_dev->notifier_ready);
 		if (err)
-			return err;
+			goto exit;
 	}
 
 	dev_info(dev, "Chrome EC device registered\n");
@@ -291,6 +291,10 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 		cros_ec_irq_thread(0, ec_dev);
 
 	return 0;
+exit:
+	platform_device_unregister(ec_dev->ec);
+	platform_device_unregister(ec_dev->pd);
+	return err;
 }
 EXPORT_SYMBOL(cros_ec_register);
 
@@ -331,14 +335,15 @@ int cros_ec_suspend(struct cros_ec_device *ec_dev)