Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1990 insertions, 0 deletions

diff --git a/drivers/hwmon/hp-wmi-sensors.c b/drivers/hwmon/hp-wmi-sensors.c
new file mode 100644
index 0000000000..17ae62f88b
--- /dev/null
+++ b/drivers/hwmon/hp-wmi-sensors.c
@@ -0,0 +1,1990 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * hwmon driver for HP (and some HP Compaq) business-class computers that
+ * report numeric sensor data via Windows Management Instrumentation (WMI).
+ *
+ * Copyright (C) 2023 James Seo <james@equiv.tech>
+ *
+ * References:
+ * [1] Hewlett-Packard Development Company, L.P.,
+ *     "HP Client Management Interface Technical White Paper", 2005. [Online].
+ *     Available: https://h20331.www2.hp.com/hpsub/downloads/cmi_whitepaper.pdf
+ * [2] Hewlett-Packard Development Company, L.P.,
+ *     "HP Retail Manageability", 2012. [Online].
+ *     Available: http://h10032.www1.hp.com/ctg/Manual/c03291135.pdf
+ * [3] Linux Hardware Project, A. Ponomarenko et al.,
+ *     "linuxhw/ACPI - Collect ACPI table dumps", 2018. [Online].
+ *     Available: https://github.com/linuxhw/ACPI
+ * [4] P. Rohár, "bmfdec - Decompile binary MOF file (BMF) from WMI buffer",
+ *     2017. [Online]. Available: https://github.com/pali/bmfdec
+ */
+
+#include <linux/acpi.h>
+#include <linux/debugfs.h>
+#include <linux/hwmon.h>
+#include <linux/jiffies.h>
+#include <linux/mutex.h>
+#include <linux/units.h>
+#include <linux/wmi.h>
+
+#define HP_WMI_EVENT_NAMESPACE		"root\\WMI"
+#define HP_WMI_EVENT_CLASS		"HPBIOS_BIOSEvent"
+#define HP_WMI_EVENT_GUID		"95F24279-4D7B-4334-9387-ACCDC67EF61C"
+#define HP_WMI_NUMERIC_SENSOR_GUID	"8F1F6435-9F42-42C8-BADC-0E9424F20C9A"
+#define HP_WMI_PLATFORM_EVENTS_GUID	"41227C2D-80E1-423F-8B8E-87E32755A0EB"
+
+/* Patterns for recognizing sensors and matching events to channels. */
+
+#define HP_WMI_PATTERN_SYS_TEMP		"Chassis Thermal Index"
+#define HP_WMI_PATTERN_SYS_TEMP2	"System Ambient Temperature"
+#define HP_WMI_PATTERN_CPU_TEMP		"CPU Thermal Index"
+#define HP_WMI_PATTERN_CPU_TEMP2	"CPU Temperature"
+#define HP_WMI_PATTERN_TEMP_SENSOR	"Thermal Index"
+#define HP_WMI_PATTERN_TEMP_ALARM	"Thermal Critical"
+#define HP_WMI_PATTERN_INTRUSION_ALARM	"Hood Intrusion"
+#define HP_WMI_PATTERN_FAN_ALARM	"Stall"
+#define HP_WMI_PATTERN_TEMP		"Temperature"
+#define HP_WMI_PATTERN_CPU		"CPU"
+
+/* These limits are arbitrary. The WMI implementation may vary by system. */
+
+#define HP_WMI_MAX_STR_SIZE		128U
+#define HP_WMI_MAX_PROPERTIES		32U
+#define HP_WMI_MAX_INSTANCES		32U
+
+enum hp_wmi_type {
+	HP_WMI_TYPE_OTHER			= 1,
+	HP_WMI_TYPE_TEMPERATURE			= 2,
+	HP_WMI_TYPE_VOLTAGE			= 3,
+	HP_WMI_TYPE_CURRENT			= 4,
+	HP_WMI_TYPE_AIR_FLOW			= 12,
+	HP_WMI_TYPE_INTRUSION			= 0xabadb01, /* Custom. */
+};
+
+enum hp_wmi_category {
+	HP_WMI_CATEGORY_SENSOR			= 3,
+};
+
+enum hp_wmi_severity {
+	HP_WMI_SEVERITY_UNKNOWN			= 0,
+	HP_WMI_SEVERITY_OK			= 5,
+	HP_WMI_SEVERITY_DEGRADED_WARNING	= 10,
+	HP_WMI_SEVERITY_MINOR_FAILURE		= 15,
+	HP_WMI_SEVERITY_MAJOR_FAILURE		= 20,
+	HP_WMI_SEVERITY_CRITICAL_FAILURE	= 25,
+	HP_WMI_SEVERITY_NON_RECOVERABLE_ERROR	= 30,
+};
+
+enum hp_wmi_status {
+	HP_WMI_STATUS_OK			= 2,
+	HP_WMI_STATUS_DEGRADED			= 3,
+	HP_WMI_STATUS_STRESSED			= 4,
+	HP_WMI_STATUS_PREDICTIVE_FAILURE	= 5,
+	HP_WMI_STATUS_ERROR			= 6,
+	HP_WMI_STATUS_NON_RECOVERABLE_ERROR	= 7,
+	HP_WMI_STATUS_NO_CONTACT		= 12,
+	HP_WMI_STATUS_LOST_COMMUNICATION	= 13,
+	HP_WMI_STATUS_ABORTED			= 14,
+	HP_WMI_STATUS_SUPPORTING_ENTITY_IN_ERROR = 16,
+
+	/* Occurs combined with one of "OK", "Degraded", and "Error" [1]. */
+	HP_WMI_STATUS_COMPLETED			= 17,
+};
+
+enum hp_wmi_units {
+	HP_WMI_UNITS_OTHER			= 1,
+	HP_WMI_UNITS_DEGREES_C			= 2,
+	HP_WMI_UNITS_DEGREES_F			= 3,
+	HP_WMI_UNITS_DEGREES_K			= 4,
+	HP_WMI_UNITS_VOLTS			= 5,
+	HP_WMI_UNITS_AMPS			= 6,
+	HP_WMI_UNITS_RPM			= 19,
+};
+
+enum hp_wmi_property {
+	HP_WMI_PROPERTY_NAME			= 0,
+	HP_WMI_PROPERTY_DESCRIPTION		= 1,
+	HP_WMI_PROPERTY_SENSOR_TYPE		= 2,
+	HP_WMI_PROPERTY_OTHER_SENSOR_TYPE	= 3,
+	HP_WMI_PROPERTY_OPERATIONAL_STATUS	= 4,
+	HP_WMI_PROPERTY_SIZE			= 5,
+	HP_WMI_PROPERTY_POSSIBLE_STATES		= 6,
+	HP_WMI_PROPERTY_CURRENT_STATE		= 7,
+	HP_WMI_PROPERTY_BASE_UNITS		= 8,
+	HP_WMI_PROPERTY_UNIT_MODIFIER		= 9,
+	HP_WMI_PROPERTY_CURRENT_READING		= 10,
+	HP_WMI_PROPERTY_RATE_UNITS		= 11,
+};
+
+static const acpi_object_type hp_wmi_property_map[] = {
+	[HP_WMI_PROPERTY_NAME]			= ACPI_TYPE_STRING,
+	[HP_WMI_PROPERTY_DESCRIPTION]		= ACPI_TYPE_STRING,
+	[HP_WMI_PROPERTY_SENSOR_TYPE]		= ACPI_TYPE_INTEGER,
+	[HP_WMI_PROPERTY_OTHER_SENSOR_TYPE]	= ACPI_TYPE_STRING,
+	[HP_WMI_PROPERTY_OPERATIONAL_STATUS]	= ACPI_TYPE_INTEGER,
+	[HP_WMI_PROPERTY_SIZE]			= ACPI_TYPE_INTEGER,
+	[HP_WMI_PROPERTY_POSSIBLE_STATES]	= ACPI_TYPE_STRING,
+	[HP_WMI_PROPERTY_CURRENT_STATE]		= ACPI_TYPE_STRING,
+	[HP_WMI_PROPERTY_BASE_UNITS]		= ACPI_TYPE_INTEGER,
+	[HP_WMI_PROPERTY_UNIT_MODIFIER]		= ACPI_TYPE_INTEGER,
+	[HP_WMI_PROPERTY_CURRENT_READING]	= ACPI_TYPE_INTEGER,
+	[HP_WMI_PROPERTY_RATE_UNITS]		= ACPI_TYPE_INTEGER,
+};
+
+enum hp_wmi_platform_events_property {
+	HP_WMI_PLATFORM_EVENTS_PROPERTY_NAME		    = 0,
+	HP_WMI_PLATFORM_EVENTS_PROPERTY_DESCRIPTION	    = 1,
+	HP_WMI_PLATFORM_EVENTS_PROPERTY_SOURCE_NAMESPACE    = 2,
+	HP_WMI_PLATFORM_EVENTS_PROPERTY_SOURCE_CLASS	    = 3,
+	HP_WMI_PLATFORM_EVENTS_PROPERTY_CATEGORY	    = 4,
+	HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_SEVERITY   = 5,
+	HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_STATUS	    = 6,
+};
+
+static const acpi_object_type hp_wmi_platform_events_property_map[] = {
+	[HP_WMI_PLATFORM_EVENTS_PROPERTY_NAME]		    = ACPI_TYPE_STRING,
+	[HP_WMI_PLATFORM_EVENTS_PROPERTY_DESCRIPTION]	    = ACPI_TYPE_STRING,
+	[HP_WMI_PLATFORM_EVENTS_PROPERTY_SOURCE_NAMESPACE]  = ACPI_TYPE_STRING,
+	[HP_WMI_PLATFORM_EVENTS_PROPERTY_SOURCE_CLASS]	    = ACPI_TYPE_STRING,
+	[HP_WMI_PLATFORM_EVENTS_PROPERTY_CATEGORY]	    = ACPI_TYPE_INTEGER,
+	[HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_SEVERITY] = ACPI_TYPE_INTEGER,
+	[HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_STATUS]   = ACPI_TYPE_INTEGER,
+};
+
+enum hp_wmi_event_property {
+	HP_WMI_EVENT_PROPERTY_NAME		= 0,
+	HP_WMI_EVENT_PROPERTY_DESCRIPTION	= 1,
+	HP_WMI_EVENT_PROPERTY_CATEGORY		= 2,
+	HP_WMI_EVENT_PROPERTY_SEVERITY		= 3,
+	HP_WMI_EVENT_PROPERTY_STATUS		= 4,
+};
+
+static const acpi_object_type hp_wmi_event_property_map[] = {
+	[HP_WMI_EVENT_PROPERTY_NAME]		= ACPI_TYPE_STRING,
+	[HP_WMI_EVENT_PROPERTY_DESCRIPTION]	= ACPI_TYPE_STRING,
+	[HP_WMI_EVENT_PROPERTY_CATEGORY]	= ACPI_TYPE_INTEGER,
+	[HP_WMI_EVENT_PROPERTY_SEVERITY]	= ACPI_TYPE_INTEGER,
+	[HP_WMI_EVENT_PROPERTY_STATUS]		= ACPI_TYPE_INTEGER,
+};
+
+static const enum hwmon_sensor_types hp_wmi_hwmon_type_map[] = {
+	[HP_WMI_TYPE_TEMPERATURE]		= hwmon_temp,
+	[HP_WMI_TYPE_VOLTAGE]			= hwmon_in,
+	[HP_WMI_TYPE_CURRENT]			= hwmon_curr,
+	[HP_WMI_TYPE_AIR_FLOW]			= hwmon_fan,
+};
+
+static const u32 hp_wmi_hwmon_attributes[hwmon_max] = {
+	[hwmon_chip]	  = HWMON_C_REGISTER_TZ,
+	[hwmon_temp]	  = HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_FAULT,
+	[hwmon_in]	  = HWMON_I_INPUT | HWMON_I_LABEL,
+	[hwmon_curr]	  = HWMON_C_INPUT | HWMON_C_LABEL,
+	[hwmon_fan]	  = HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_FAULT,
+	[hwmon_intrusion] = HWMON_INTRUSION_ALARM,
+};
+
+/*
+ * struct hp_wmi_numeric_sensor - a HPBIOS_BIOSNumericSensor instance
+ *
+ * Two variants of HPBIOS_BIOSNumericSensor are known. The first is specified
+ * in [1] and appears to be much more widespread. The second was discovered by
+ * decoding BMOF blobs [4], seems to be found only in some newer ZBook systems
+ * [3], and has two new properties and a slightly different property order.
+ *
+ * These differences don't matter on Windows, where WMI object properties are
+ * accessed by name. For us, supporting both variants gets ugly and hacky at
+ * times. The fun begins now; this struct is defined as per the new variant.
+ *
+ * Effective MOF definition:
+ *
+ *   #pragma namespace("\\\\.\\root\\HP\\InstrumentedBIOS");
+ *   class HPBIOS_BIOSNumericSensor {
+ *     [read] string Name;
+ *     [read] string Description;
+ *     [read, ValueMap {"0","1","2","3","4","5","6","7","8","9",
+ *      "10","11","12"}, Values {"Unknown","Other","Temperature",
+ *      "Voltage","Current","Tachometer","Counter","Switch","Lock",
+ *      "Humidity","Smoke Detection","Presence","Air Flow"}]
+ *     uint32 SensorType;
+ *     [read] string OtherSensorType;
+ *     [read, ValueMap {"0","1","2","3","4","5","6","7","8","9",
+ *      "10","11","12","13","14","15","16","17","18","..",
+ *      "0x8000.."}, Values {"Unknown","Other","OK","Degraded",
+ *      "Stressed","Predictive Failure","Error",
+ *      "Non-Recoverable Error","Starting","Stopping","Stopped",
+ *      "In Service","No Contact","Lost Communication","Aborted",
+ *      "Dormant","Supporting Entity in Error","Completed",
+ *      "Power Mode","DMTF Reserved","Vendor Reserved"}]
+ *     uint32 OperationalStatus;
+ *     [read] uint32 Size;
+ *     [read] string PossibleStates[];
+ *     [read] string CurrentState;
+ *     [read, ValueMap {"0","1","2","3","4","5","6","7","8","9",
+ *      "10","11","12","13","14","15","16","17","18","19","20",
+ *      "21","22","23","24","25","26","27","28","29","30","31",
+ *      "32","33","34","35","36","37","38","39","40","41","42",
+ *      "43","44","45","46","47","48","49","50","51","52","53",
+ *      "54","55","56","57","58","59","60","61","62","63","64",
+ *      "65"}, Values {"Unknown","Other","Degrees C","Degrees F",
+ *      "Degrees K","Volts","Amps","Watts","Joules","Coulombs",
+ *      "VA","Nits","Lumens","Lux","Candelas","kPa","PSI",
+ *      "Newtons","CFM","RPM","Hertz","Seconds","Minutes",
+ *      "Hours","Days","Weeks","Mils","Inches","Feet",
+ *      "Cubic Inches","Cubic Feet","Meters","Cubic Centimeters",
+ *      "Cubic Meters","Liters","Fluid Ounces","Radians",
+ *      "Steradians","Revolutions","Cycles","Gravities","Ounces",
+ *      "Pounds","Foot-Pounds","Ounce-Inches","Gauss","Gilberts",
+ *      "Henries","Farads","Ohms","Siemens","Moles","Becquerels",
+ *      "PPM (parts/million)","Decibels","DbA","DbC","Grays",
+ *      "Sieverts","Color Temperature Degrees K","Bits","Bytes",
+ *      "Words (data)","DoubleWords","QuadWords","Percentage"}]
+ *     uint32 BaseUnits;
+ *     [read] sint32 UnitModifier;
+ *     [read] uint32 CurrentReading;
+ *     [read] uint32 RateUnits;
+ *   };
+ *
+ * Effective MOF definition of old variant [1] (sans redundant info):
+ *
+ *   class HPBIOS_BIOSNumericSensor {
+ *     [read] string Name;
+ *     [read] string Description;
+ *     [read] uint32 SensorType;
+ *     [read] string OtherSensorType;
+ *     [read] uint32 OperationalStatus;
+ *     [read] string CurrentState;
+ *     [read] string PossibleStates[];
+ *     [read] uint32 BaseUnits;
+ *     [read] sint32 UnitModifier;
+ *     [read] uint32 CurrentReading;
+ *   };
+ */
+struct hp_wmi_numeric_sensor {
+	const char *name;
+	const char *description;
+	u32 sensor_type;
+	const char *other_sensor_type;	/* Explains "Other" SensorType. */
+	u32 operational_status;
+	u8 size;			/* Count of PossibleStates[]. */
+	const char **possible_states;
+	const char *current_state;
+	u32 base_units;
+	s32 unit_modifier;
+	u32 current_reading;
+	u32 rate_units;
+};
+
+/*
+ * struct hp_wmi_platform_events - a HPBIOS_PlatformEvents instance
+ *
+ * Instances of this object reveal the set of possible HPBIOS_BIOSEvent
+ * instances for the current system, but it may not always be present.
+ *
+ * Effective MOF definition:
+ *
+ *   #pragma namespace("\\\\.\\root\\HP\\InstrumentedBIOS");
+ *   class HPBIOS_PlatformEvents {
+ *     [read] string Name;
+ *     [read] string Description;
+ *     [read] string SourceNamespace;
+ *     [read] string SourceClass;
+ *     [read, ValueMap {"0","1","2","3","4",".."}, Values {
+ *      "Unknown","Configuration Change","Button Pressed",
+ *      "Sensor","BIOS Settings","Reserved"}]
+ *     uint32 Category;
+ *     [read, ValueMap{"0","5","10","15","20","25","30",".."},
+ *      Values{"Unknown","OK","Degraded/Warning","Minor Failure",
+ *      "Major Failure","Critical Failure","Non-recoverable Error",
+ *      "DMTF Reserved"}]
+ *     uint32 PossibleSeverity;
+ *     [read, ValueMap {"0","1","2","3","4","5","6","7","8","9",
+ *      "10","11","12","13","14","15","16","17","18","..",
+ *      "0x8000.."}, Values {"Unknown","Other","OK","Degraded",
+ *      "Stressed","Predictive Failure","Error",
+ *      "Non-Recoverable Error","Starting","Stopping","Stopped",
+ *      "In Service","No Contact","Lost Communication","Aborted",
+ *      "Dormant","Supporting Entity in Error","Completed",
+ *      "Power Mode","DMTF Reserved","Vendor Reserved"}]
+ *     uint32 PossibleStatus;
+ *   };
+ */
+struct hp_wmi_platform_events {
+	const char *name;
+	const char *description;
+	const char *source_namespace;
+	const char *source_class;
+	u32 category;
+	u32 possible_severity;
+	u32 possible_status;
+};
+
+/*
+ * struct hp_wmi_event - a HPBIOS_BIOSEvent instance
+ *
+ * Effective MOF definition [1] (corrected below from original):
+ *
+ *   #pragma namespace("\\\\.\\root\\WMI");
+ *   class HPBIOS_BIOSEvent : WMIEvent {
+ *     [read] string Name;
+ *     [read] string Description;
+ *     [read ValueMap {"0","1","2","3","4"}, Values {"Unknown",
+ *      "Configuration Change","Button Pressed","Sensor",
+ *      "BIOS Settings"}]
+ *     uint32 Category;
+ *     [read, ValueMap {"0","5","10","15","20","25","30"},
+ *      Values {"Unknown","OK","Degraded/Warning",
+ *      "Minor Failure","Major Failure","Critical Failure",
+ *      "Non-recoverable Error"}]
+ *     uint32 Severity;
+ *     [read, ValueMap {"0","1","2","3","4","5","6","7","8",
+ *      "9","10","11","12","13","14","15","16","17","18","..",
+ *      "0x8000.."}, Values {"Unknown","Other","OK","Degraded",
+ *      "Stressed","Predictive Failure","Error",
+ *      "Non-Recoverable Error","Starting","Stopping","Stopped",
+ *      "In Service","No Contact","Lost Communication","Aborted",
+ *      "Dormant","Supporting Entity in Error","Completed",
+ *      "Power Mode","DMTF Reserved","Vendor Reserved"}]
+ *     uint32 Status;
+ *   };
+ */
+struct hp_wmi_event {
+	const char *name;
+	const char *description;
+	u32 category;
+};
+
+/*
+ * struct hp_wmi_info - sensor info
+ * @nsensor: numeric sensor properties
+ * @instance: its WMI instance number
+ * @state: pointer to driver state
+ * @has_alarm: whether sensor has an alarm flag
+ * @alarm: alarm flag
+ * @type: its hwmon sensor type
+ * @cached_val: current sensor reading value, scaled for hwmon
+ * @last_updated: when these readings were last updated
+ */
+struct hp_wmi_info {
+	struct hp_wmi_numeric_sensor nsensor;
+	u8 instance;
+	void *state;			/* void *: Avoid forward declaration. */
+	bool has_alarm;
+	bool alarm;
+	enum hwmon_sensor_types type;
+	long cached_val;
+	unsigned long last_updated;	/* In jiffies. */
+
+};
+
+/*
+ * struct hp_wmi_sensors - driver state
+ * @wdev: pointer to the parent WMI device
+ * @info_map: sensor info structs by hwmon type and channel number
+ * @channel_count: count of hwmon channels by hwmon type
+ * @has_intrusion: whether an intrusion sensor is present
+ * @intrusion: intrusion flag
+ * @lock: mutex to lock polling WMI and changes to driver state
+ */
+struct hp_wmi_sensors {
+	struct wmi_device *wdev;
+	struct hp_wmi_info **info_map[hwmon_max];
+	u8 channel_count[hwmon_max];
+	bool has_intrusion;
+	bool intrusion;
+
+	struct mutex lock;	/* Lock polling WMI and driver state changes. */
+};
+
+/* hp_wmi_strdup - devm_kstrdup, but length-limited */
+static char *hp_wmi_strdup(struct device *dev, const char *src)
+{
+	char *dst;
+	size_t len;
+
+	len = strnlen(src, HP_WMI_MAX_STR_SIZE - 1);
+
+	dst = devm_kmalloc(dev, (len + 1) * sizeof(*dst), GFP_KERNEL);
+	if (!dst)
+		return NULL;
+
+	strscpy(dst, src, len + 1);
+
+	return dst;
+}
+
+/*
+ * hp_wmi_get_wobj - poll WMI for a WMI object instance
+ * @guid: WMI object GUID
+ * @instance: WMI object instance number
+ *
+ * Returns a new WMI object instance on success, or NULL on error.
+ * Caller must kfree() the result.
+ */
+static union acpi_object *hp_wmi_get_wobj(const char *guid, u8 instance)
+{
+	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
+	acpi_status err;
+
+	err = wmi_query_block(guid, instance, &out);
+	if (ACPI_FAILURE(err))
+		return NULL;
+
+	return out.pointer;
+}
+
+/* hp_wmi_wobj_instance_count - find count of WMI object instances */
+static u8 hp_wmi_wobj_instance_count(const char *guid)
+{
+	int count;
+
+	count = wmi_instance_count(guid);
+
+	return clamp(count, 0, (int)HP_WMI_MAX_INSTANCES);
+}
+
+static int check_wobj(const union acpi_object *wobj,
+		      const acpi_object_type property_map[], int last_prop)
+{
+	acpi_object_type type = wobj->type;
+	acpi_object_type valid_type;
+	union acpi_object *elements;
+	u32 elem_count;
+	int prop;
+
+	if (type != ACPI_TYPE_PACKAGE)
+		return -EINVAL;
+
+	elem_count = wobj->package.count;
+	if (elem_count != last_prop + 1)
+		return -EINVAL;
+
+	elements = wobj->package.elements;
+	for (prop = 0; prop <= last_prop; prop++) {
+		type = elements[prop].type;
+		valid_type = property_map[prop];
+		if (type != valid_type)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int extract_acpi_value(struct device *dev,
+			      union acpi_object *element,
+			      acpi_object_type type,
+			      u32 *out_value, char **out_string)
+{
+	switch (type) {
+	case ACPI_TYPE_INTEGER:
+		*out_value = element->integer.value;
+		break;
+
+	case ACPI_TYPE_STRING:
+		*out_string = hp_wmi_strdup(dev, strim(element->string.pointer));
+		if (!*out_string)
+			return -ENOMEM;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * check_numeric_sensor_wobj - validate a HPBIOS_BIOSNumericSensor instance
+ * @wobj: pointer to WMI object instance to check
+ * @out_size: out pointer to count of possible states
+ * @out_is_new: out pointer to whether this is a "new" variant object
+ *
+ * Returns 0 on success, or a negative error code on error.
+ */
+static int check_numeric_sensor_wobj(const union acpi_object *wobj,
+				     u8 *out_size, bool *out_is_new)
+{
+	acpi_object_type type = wobj->type;
+	int prop = HP_WMI_PROPERTY_NAME;
+	acpi_object_type valid_type;
+	union acpi_object *elements;
+	u32 elem_count;
+	int last_prop;
+	bool is_new;
+	u8 count;
+	u32 j;
+	u32 i;
+
+	if (type != ACPI_TYPE_PACKAGE)
+		return -EINVAL;
+
+	/*
+	 * elements is a variable-length array of ACPI objects, one for
+	 * each property of the WMI object instance, except that the
+	 * strings in PossibleStates[] are flattened into this array
+	 * as if each individual string were a property by itself.
+	 */
+	elements = wobj->package.elements;
+
+	elem_count = wobj->package.count;
+	if (elem_count <= HP_WMI_PROPERTY_SIZE ||
+	    elem_count > HP_WMI_MAX_PROPERTIES)
+		return -EINVAL;
+
+	type = elements[HP_WMI_PROPERTY_SIZE].type;
+	switch (type) {
+	case ACPI_TYPE_INTEGER:
+		is_new = true;
+		last_prop = HP_WMI_PROPERTY_RATE_UNITS;
+		break;
+
+	case ACPI_TYPE_STRING:
+		is_new = false;
+		last_prop = HP_WMI_PROPERTY_CURRENT_READING;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	/*
+	 * In general, the count of PossibleStates[] must be > 0.
+	 * Also, the old variant lacks the Size property, so we may need to
+	 * reduce the value of last_prop by 1 when doing arithmetic with it.
+	 */
+	if (elem_count < last_prop - !is_new + 1)
+		return -EINVAL;
+
+	count = elem_count - (last_prop - !is_new);
+
+	for (i = 0; i < elem_count && prop <= last_prop; i++, prop++) {
+		type = elements[i].type;
+		valid_type = hp_wmi_property_map[prop];
+		if (type != valid_type)
+			return -EINVAL;
+
+		switch (prop) {
+		case HP_WMI_PROPERTY_OPERATIONAL_STATUS:
+			/* Old variant: CurrentState follows OperationalStatus. */
+			if (!is_new)
+				prop = HP_WMI_PROPERTY_CURRENT_STATE - 1;
+			break;
+
+		case HP_WMI_PROPERTY_SIZE:
+			/* New variant: Size == count of PossibleStates[]. */
+			if (count != elements[i].integer.value)
+				return -EINVAL;
+			break;
+
+		case HP_WMI_PROPERTY_POSSIBLE_STATES:
+			/* PossibleStates[0] has already been type-checked. */
+			for (j = 0; i + 1 < elem_count && j + 1 < count; j++) {
+				type = elements[++i].type;
+				if (type != valid_type)
+					return -EINVAL;
+			}
+
+			/* Old variant: BaseUnits follows PossibleStates[]. */
+			if (!is_new)
+				prop = HP_WMI_PROPERTY_BASE_UNITS - 1;
+			break;
+
+		case HP_WMI_PROPERTY_CURRENT_STATE:
+			/* Old variant: PossibleStates[] follows CurrentState. */
+			if (!is_new)
+				prop = HP_WMI_PROPERTY_POSSIBLE_STATES - 1;
+			break;
+		}
+	}
+
+	if (prop != last_prop + 1)
+		return -EINVAL;
+
+	*out_size = count;
+	*out_is_new = is_new;
+
+	return 0;
+}
+
+static int
+numeric_sensor_is_connected(const struct hp_wmi_numeric_sensor *nsensor)
+{
+	u32 operational_status = nsensor->operational_status;
+
+	return operational_status != HP_WMI_STATUS_NO_CONTACT;
+}
+
+static int numeric_sensor_has_fault(const struct hp_wmi_numeric_sensor *nsensor)
+{
+	u32 operational_status = nsensor->operational_status;
+
+	switch (operational_status) {
+	case HP_WMI_STATUS_DEGRADED:
+	case HP_WMI_STATUS_STRESSED:		/* e.g. Overload, overtemp. */
+	case HP_WMI_STATUS_PREDICTIVE_FAILURE:	/* e.g. Fan removed. */
+	case HP_WMI_STATUS_ERROR:
+	case HP_WMI_STATUS_NON_RECOVERABLE_ERROR:
+	case HP_WMI_STATUS_NO_CONTACT:
+	case HP_WMI_STATUS_LOST_COMMUNICATION:
+	case HP_WMI_STATUS_ABORTED:
+	case HP_WMI_STATUS_SUPPORTING_ENTITY_IN_ERROR:
+
+	/* Assume combination by addition; bitwise OR doesn't make sense. */
+	case HP_WMI_STATUS_COMPLETED + HP_WMI_STATUS_DEGRADED:
+	case HP_WMI_STATUS_COMPLETED + HP_WMI_STATUS_ERROR:
+		return true;
+	}
+
+	return false;
+}
+
+/* scale_numeric_sensor - scale sensor reading for hwmon */
+static long scale_numeric_sensor(const struct hp_wmi_numeric_sensor *nsensor)
+{
+	u32 current_reading = nsensor->current_reading;
+	s32 unit_modifier = nsensor->unit_modifier;
+	u32 sensor_type = nsensor->sensor_type;
+	u32 base_units = nsensor->base_units;
+	s32 target_modifier;
+	long val;
+
+	/* Fan readings are in RPM units; others are in milliunits. */
+	target_modifier = sensor_type == HP_WMI_TYPE_AIR_FLOW ? 0 : -3;
+
+	val = current_reading;
+
+	for (; unit_modifier < target_modifier; unit_modifier++)
+		val = DIV_ROUND_CLOSEST(val, 10);
+
+	for (; unit_modifier > target_modifier; unit_modifier--) {
+		if (val > LONG_MAX / 10) {
+			val = LONG_MAX;
+			break;
+		}
+		val *= 10;
+	}
+
+	if (sensor_type == HP_WMI_TYPE_TEMPERATURE) {
+		switch (base_units) {
+		case HP_WMI_UNITS_DEGREES_F:
+			val -= MILLI * 32;
+			val = val <= LONG_MAX / 5 ?
+				      DIV_ROUND_CLOSEST(val * 5, 9) :
+				      DIV_ROUND_CLOSEST(val, 9) * 5;
+			break;
+
+		case HP_WMI_UNITS_DEGREES_K:
+			val = milli_kelvin_to_millicelsius(val);
+			break;
+		}
+	}
+
+	return val;
+}
+
+/*
+ * classify_numeric_sensor - classify a numeric sensor
+ * @nsensor: pointer to numeric sensor struct
+ *
+ * Returns an enum hp_wmi_type value on success,
+ * or a negative value if the sensor type is unsupported.
+ */
+static int classify_numeric_sensor(const struct hp_wmi_numeric_sensor *nsensor)
+{
+	u32 sensor_type = nsensor->sensor_type;
+	u32 base_units = nsensor->base_units;
+	const char *name = nsensor->name;
+
+	switch (sensor_type) {
+	case HP_WMI_TYPE_TEMPERATURE:
+		/*
+		 * Some systems have sensors named "X Thermal Index" in "Other"
+		 * units. Tested CPU sensor examples were found to be in °C,
+		 * albeit perhaps "differently" accurate; e.g. readings were
+		 * reliably -6°C vs. coretemp on a HP Compaq Elite 8300, and
+		 * +8°C on an EliteOne G1 800. But this is still within the
+		 * realm of plausibility for cheaply implemented motherboard
+		 * sensors, and chassis readings were about as expected.
+		 */
+		if ((base_units == HP_WMI_UNITS_OTHER &&
+		     strstr(name, HP_WMI_PATTERN_TEMP_SENSOR)) ||
+		    base_units == HP_WMI_UNITS_DEGREES_C ||
+		    base_units == HP_WMI_UNITS_DEGREES_F ||
+		    base_units == HP_WMI_UNITS_DEGREES_K)
+			return HP_WMI_TYPE_TEMPERATURE;
+		break;
+
+	case HP_WMI_TYPE_VOLTAGE:
+		if (base_units == HP_WMI_UNITS_VOLTS)
+			return HP_WMI_TYPE_VOLTAGE;
+		break;
+
+	case HP_WMI_TYPE_CURRENT:
+		if (base_units == HP_WMI_UNITS_AMPS)
+			return HP_WMI_TYPE_CURRENT;
+		break;
+
+	case HP_WMI_TYPE_AIR_FLOW:
+		/*
+		 * Strangely, HP considers fan RPM sensor type to be
+		 * "Air Flow" instead of the more intuitive "Tachometer".
+		 */
+		if (base_units == HP_WMI_UNITS_RPM)
+			return HP_WMI_TYPE_AIR_FLOW;
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static int
+populate_numeric_sensor_from_wobj(struct device *dev,
+				  struct hp_wmi_numeric_sensor *nsensor,
+				  union acpi_object *wobj, bool *out_is_new)
+{
+	int last_prop = HP_WMI_PROPERTY_RATE_UNITS;
+	int prop = HP_WMI_PROPERTY_NAME;
+	const char **possible_states;
+	union acpi_object *element;
+	acpi_object_type type;
+	char *string;
+	bool is_new;
+	u32 value;
+	u8 size;
+	int err;
+
+	err = check_numeric_sensor_wobj(wobj, &size, &is_new);
+	if (err)
+		return err;
+
+	possible_states = devm_kcalloc(dev, size, sizeof(*possible_states),
+				       GFP_KERNEL);
+	if (!possible_states)
+		return -ENOMEM;
+
+	element = wobj->package.elements;
+	nsensor->possible_states = possible_states;
+	nsensor->size = size;
+
+	if (!is_new)
+		last_prop = HP_WMI_PROPERTY_CURRENT_READING;
+
+	for (; prop <= last_prop; prop++) {
+		type = hp_wmi_property_map[prop];
+
+		err = extract_acpi_value(dev, element, type, &value, &string);
+		if (err)
+			return err;
+
+		element++;
+
+		switch (prop) {
+		case HP_WMI_PROPERTY_NAME:
+			nsensor->name = string;
+			break;
+
+		case HP_WMI_PROPERTY_DESCRIPTION:
+			nsensor->description = string;
+			break;
+
+		case HP_WMI_PROPERTY_SENSOR_TYPE:
+			if (value > HP_WMI_TYPE_AIR_FLOW)
+				return -EINVAL;
+
+			nsensor->sensor_type = value;
+			break;
+
+		case HP_WMI_PROPERTY_OTHER_SENSOR_TYPE:
+			nsensor->other_sensor_type = string;
+			break;
+
+		case HP_WMI_PROPERTY_OPERATIONAL_STATUS:
+			nsensor->operational_status = value;
+
+			/* Old variant: CurrentState follows OperationalStatus. */
+			if (!is_new)
+				prop = HP_WMI_PROPERTY_CURRENT_STATE - 1;
+			break;
+
+		case HP_WMI_PROPERTY_SIZE:
+			break;			/* Already set. */
+
+		case HP_WMI_PROPERTY_POSSIBLE_STATES:
+			*possible_states++ = string;
+			if (--size)
+				prop--;
+
+			/* Old variant: BaseUnits follows PossibleStates[]. */
+			if (!is_new && !size)
+				prop = HP_WMI_PROPERTY_BASE_UNITS - 1;
+			break;
+
+		case HP_WMI_PROPERTY_CURRENT_STATE:
+			nsensor->current_state = string;
+
+			/* Old variant: PossibleStates[] follows CurrentState. */
+			if (!is_new)
+				prop = HP_WMI_PROPERTY_POSSIBLE_STATES - 1;
+			break;
+
+		case HP_WMI_PROPERTY_BASE_UNITS:
+			nsensor->base_units = value;
+			break;
+
+		case HP_WMI_PROPERTY_UNIT_MODIFIER:
+			/* UnitModifier is signed. */
+			nsensor->unit_modifier = (s32)value;
+			break;
+
+		case HP_WMI_PROPERTY_CURRENT_READING:
+			nsensor->current_reading = value;
+			break;
+
+		case HP_WMI_PROPERTY_RATE_UNITS:
+			nsensor->rate_units = value;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+	}
+
+	*out_is_new = is_new;
+
+	return 0;
+}
+
+/* update_numeric_sensor_from_wobj - update fungible sensor properties */
+static void
+update_numeric_sensor_from_wobj(struct device *dev,
+				struct hp_wmi_numeric_sensor *nsensor,
+				const union acpi_object *wobj)
+{
+	const union acpi_object *elements;
+	const union acpi_object *element;
+	const char *string;
+	bool is_new;
+	int offset;
+	u8 size;
+	int err;
+
+	err = check_numeric_sensor_wobj(wobj, &size, &is_new);
+	if (err)
+		return;
+
+	elements = wobj->package.elements;
+
+	element = &elements[HP_WMI_PROPERTY_OPERATIONAL_STATUS];
+	nsensor->operational_status = element->integer.value;
+
+	/*
+	 * In general, an index offset is needed after PossibleStates[0].
+	 * On a new variant, CurrentState is after PossibleStates[]. This is
+	 * not the case on an old variant, but we still need to offset the
+	 * read because CurrentState is where Size would be on a new variant.
+	 */
+	offset = is_new ? size - 1 : -2;
+
+	element = &elements[HP_WMI_PROPERTY_CURRENT_STATE + offset];
+	string = strim(element->string.pointer);
+
+	if (strcmp(string, nsensor->current_state)) {
+		devm_kfree(dev, nsensor->current_state);
+		nsensor->current_state = hp_wmi_strdup(dev, string);
+	}
+
+	/* Old variant: -2 (not -1) because it lacks the Size property. */
+	if (!is_new)
+		offset = (int)size - 2;	/* size is > 0, i.e. may be 1. */
+
+	element = &elements[HP_WMI_PROPERTY_UNIT_MODIFIER + offset];
+	nsensor->unit_modifier = (s32)element->integer.value;
+
+	element = &elements[HP_WMI_PROPERTY_CURRENT_READING + offset];
+	nsensor->current_reading = element->integer.value;
+}
+
+/*
+ * check_platform_events_wobj - validate a HPBIOS_PlatformEvents instance
+ * @wobj: pointer to WMI object instance to check
+ *
+ * Returns 0 on success, or a negative error code on error.
+ */
+static int check_platform_events_wobj(const union acpi_object *wobj)
+{
+	return check_wobj(wobj, hp_wmi_platform_events_property_map,
+			  HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_STATUS);
+}
+
+static int
+populate_platform_events_from_wobj(struct device *dev,
+				   struct hp_wmi_platform_events *pevents,
+				   union acpi_object *wobj)
+{
+	int last_prop = HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_STATUS;
+	int prop = HP_WMI_PLATFORM_EVENTS_PROPERTY_NAME;
+	union acpi_object *element;
+	acpi_object_type type;
+	char *string;
+	u32 value;
+	int err;
+
+	err = check_platform_events_wobj(wobj);
+	if (err)
+		return err;
+
+	element = wobj->package.elements;
+
+	for (; prop <= last_prop; prop++, element++) {
+		type = hp_wmi_platform_events_property_map[prop];
+
+		err = extract_acpi_value(dev, element, type, &value, &string);
+		if (err)
+			return err;
+
+		switch (prop) {
+		case HP_WMI_PLATFORM_EVENTS_PROPERTY_NAME:
+			pevents->name = string;
+			break;
+
+		case HP_WMI_PLATFORM_EVENTS_PROPERTY_DESCRIPTION:
+			pevents->description = string;
+			break;
+
+		case HP_WMI_PLATFORM_EVENTS_PROPERTY_SOURCE_NAMESPACE:
+			if (strcasecmp(HP_WMI_EVENT_NAMESPACE, string))
+				return -EINVAL;
+
+			pevents->source_namespace = string;
+			break;
+
+		case HP_WMI_PLATFORM_EVENTS_PROPERTY_SOURCE_CLASS:
+			if (strcasecmp(HP_WMI_EVENT_CLASS, string))
+				return -EINVAL;
+
+			pevents->source_class = string;
+			break;
+
+		case HP_WMI_PLATFORM_EVENTS_PROPERTY_CATEGORY:
+			pevents->category = value;
+			break;
+
+		case HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_SEVERITY:
+			pevents->possible_severity = value;
+			break;
+
+		case HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_STATUS:
+			pevents->possible_status = value;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * check_event_wobj - validate a HPBIOS_BIOSEvent instance
+ * @wobj: pointer to WMI object instance to check
+ *
+ * Returns 0 on success, or a negative error code on error.
+ */
+static int check_event_wobj(const union acpi_object *wobj)
+{
+	return check_wobj(wobj, hp_wmi_event_property_map,
+			  HP_WMI_EVENT_PROPERTY_STATUS);
+}
+
+static int populate_event_from_wobj(struct hp_wmi_event *event,
+				    union acpi_object *wobj)
+{
+	int prop = HP_WMI_EVENT_PROPERTY_NAME;
+	union acpi_object *element;
+	int err;
+
+	err = check_event_wobj(wobj);
+	if (err)
+		return err;
+
+	element = wobj->package.elements;
+
+	/* Extracted strings are NOT device-managed copies. */
+
+	for (; prop <= HP_WMI_EVENT_PROPERTY_CATEGORY; prop++, element++) {
+		switch (prop) {
+		case HP_WMI_EVENT_PROPERTY_NAME:
+			event->name = strim(element->string.pointer);
+			break;
+
+		case HP_WMI_EVENT_PROPERTY_DESCRIPTION:
+			event->description = strim(element->string.pointer);
+			break;
+
+		case HP_WMI_EVENT_PROPERTY_CATEGORY:
+			event->category = element->integer.value;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * classify_event - classify an event
+ * @name: event name
+ * @category: event category
+ *
+ * Classify instances of both HPBIOS_PlatformEvents and HPBIOS_BIOSEvent from
+ * property values. Recognition criteria are based on multiple ACPI dumps [3].
+ *
+ * Returns an enum hp_wmi_type value on success,
+ * or a negative value if the event type is unsupported.
+ */
+static int classify_event(const char *event_name, u32 category)
+{
+	if (category != HP_WMI_CATEGORY_SENSOR)
+		return -EINVAL;
+
+	/* Fan events have Name "X Stall". */
+	if (strstr(event_name, HP_WMI_PATTERN_FAN_ALARM))
+		return HP_WMI_TYPE_AIR_FLOW;
+
+	/* Intrusion events have Name "Hood Intrusion". */
+	if (!strcmp(event_name, HP_WMI_PATTERN_INTRUSION_ALARM))
+		return HP_WMI_TYPE_INTRUSION;
+
+	/*
+	 * Temperature events have Name either "Thermal Caution" or
+	 * "Thermal Critical". Deal only with "Thermal Critical" events.
+	 *
+	 * "Thermal Caution" events have Status "Stressed", informing us that
+	 * the OperationalStatus of the related sensor has become "Stressed".
+	 * However, this is already a fault condition that will clear itself
+	 * when the sensor recovers, so we have no further interest in them.
+	 */
+	if (!strcmp(event_name, HP_WMI_PATTERN_TEMP_ALARM))
+		return HP_WMI_TYPE_TEMPERATURE;
+
+	return -EINVAL;
+}
+
+/*
+ * interpret_info - interpret sensor for hwmon
+ * @info: pointer to sensor info struct
+ *
+ * Should be called after the numeric sensor member has been updated.
+ */
+static void interpret_info(struct hp_wmi_info *info)
+{
+	const struct hp_wmi_numeric_sensor *nsensor = &info->nsensor;
+
+	info->cached_val = scale_numeric_sensor(nsensor);
+	info->last_updated = jiffies;
+}
+
+/*
+ * hp_wmi_update_info - poll WMI to update sensor info
+ * @state: pointer to driver state
+ * @info: pointer to sensor info struct
+ *
+ * Returns 0 on success, or a negative error code on error.
+ */
+static int hp_wmi_update_info(struct hp_wmi_sensors *state,
+			      struct hp_wmi_info *info)
+{
+	struct hp_wmi_numeric_sensor *nsensor = &info->nsensor;
+	struct device *dev = &state->wdev->dev;
+	const union acpi_object *wobj;
+	u8 instance = info->instance;
+	int ret = 0;
+
+	if (time_after(jiffies, info->last_updated + HZ)) {
+		mutex_lock(&state->lock);
+
+		wobj = hp_wmi_get_wobj(HP_WMI_NUMERIC_SENSOR_GUID, instance);
+		if (!wobj) {
+			ret = -EIO;
+			goto out_unlock;
+		}
+
+		update_numeric_sensor_from_wobj(dev, nsensor, wobj);
+
+		interpret_info(info);
+
+		kfree(wobj);
+
+out_unlock:
+		mutex_unlock(&state->lock);
+	}
+
+	return ret;
+}
+
+static int basic_string_show(struct seq_file *seqf, void *ignored)
+{
+	const char *str = seqf->private;
+
+	seq_printf(seqf, "%s\n", str);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(basic_string);
+
+static int fungible_show(struct seq_file *seqf, enum hp_wmi_property prop)
+{
+	struct hp_wmi_numeric_sensor *nsensor;
+	struct hp_wmi_sensors *state;
+	struct hp_wmi_info *info;
+	int err;
+
+	info = seqf->private;
+	state = info->state;
+	nsensor = &info->nsensor;
+
+	err = hp_wmi_update_info(state, info);
+	if (err)
+		return err;
+
+	switch (prop) {
+	case HP_WMI_PROPERTY_OPERATIONAL_STATUS:
+		seq_printf(seqf, "%u\n", nsensor->operational_status);
+		break;
+
+	case HP_WMI_PROPERTY_CURRENT_STATE:
+		seq_printf(seqf, "%s\n", nsensor->current_state);
+		break;
+
+	case HP_WMI_PROPERTY_UNIT_MODIFIER:
+		seq_printf(seqf, "%d\n", nsensor->unit_modifier);
+		break;
+
+	case HP_WMI_PROPERTY_CURRENT_READING:
+		seq_printf(seqf, "%u\n", nsensor->current_reading);
+		break;
+
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int operational_status_show(struct seq_file *seqf, void *ignored)
+{
+	return fungible_show(seqf, HP_WMI_PROPERTY_OPERATIONAL_STATUS);
+}
+DEFINE_SHOW_ATTRIBUTE(operational_status);
+
+static int current_state_show(struct seq_file *seqf, void *ignored)
+{
+	return fungible_show(seqf, HP_WMI_PROPERTY_CURRENT_STATE);
+}
+DEFINE_SHOW_ATTRIBUTE(current_state);
+
+static int possible_states_show(struct seq_file *seqf, void *ignored)
+{
+	struct hp_wmi_numeric_sensor *nsensor = seqf->private;
+	u8 i;
+
+	for (i = 0; i < nsensor->size; i++)
+		seq_printf(seqf, "%s%s", i ? "," : "",
+			   nsensor->possible_states[i]);
+
+	seq_puts(seqf, "\n");
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(possible_states);
+
+static int unit_modifier_show(struct seq_file *seqf, void *ignored)
+{
+	return fungible_show(seqf, HP_WMI_PROPERTY_UNIT_MODIFIER);
+}
+DEFINE_SHOW_ATTRIBUTE(unit_modifier);
+
+static int current_reading_show(struct seq_file *seqf, void *ignored)
+{
+	return fungible_show(seqf, HP_WMI_PROPERTY_CURRENT_READING);
+}
+DEFINE_SHOW_ATTRIBUTE(current_reading);
+
+/* hp_wmi_devm_debugfs_remove - devm callback for debugfs cleanup */
+static void hp_wmi_devm_debugfs_remove(void *res)
+{
+	debugfs_remove_recursive(res);
+}
+
+/* hp_wmi_debugfs_init - create and populate debugfs directory tree */
+static void hp_wmi_debugfs_init(struct device *dev, struct hp_wmi_info *info,
+				struct hp_wmi_platform_events *pevents,
+				u8 icount, u8 pcount, bool is_new)
+{
+	struct hp_wmi_numeric_sensor *nsensor;
+	char buf[HP_WMI_MAX_STR_SIZE];
+	struct dentry *debugfs;
+	struct dentry *entries;
+	struct dentry *dir;
+	int err;
+	u8 i;
+
+	/* dev_name() gives a not-very-friendly GUID for WMI devices. */
+	scnprintf(buf, sizeof(buf), "hp-wmi-sensors-%u", dev->id);
+
+	debugfs = debugfs_create_dir(buf, NULL);
+	if (IS_ERR(debugfs))
+		return;
+
+	err = devm_add_action_or_reset(dev, hp_wmi_devm_debugfs_remove,
+				       debugfs);
+	if (err)
+		return;
+
+	entries = debugfs_create_dir("sensor", debugfs);
+
+	for (i = 0; i < icount; i++, info++) {
+		nsensor = &info->nsensor;
+
+		scnprintf(buf, sizeof(buf), "%u", i);
+		dir = debugfs_create_dir(buf, entries);
+
+		debugfs_create_file("name", 0444, dir,
+				    (void *)nsensor->name,
+				    &basic_string_fops);
+
+		debugfs_create_file("description", 0444, dir,
+				    (void *)nsensor->description,
+				    &basic_string_fops);
+
+		debugfs_create_u32("sensor_type", 0444, dir,
+				   &nsensor->sensor_type);
+
+		debugfs_create_file("other_sensor_type", 0444, dir,
+				    (void *)nsensor->other_sensor_type,
+				    &basic_string_fops);
+
+		debugfs_create_file("operational_status", 0444, dir,
+				    info, &operational_status_fops);
+
+		debugfs_create_file("possible_states", 0444, dir,
+				    nsensor, &possible_states_fops);
+
+		debugfs_create_file("current_state", 0444, dir,
+				    info, &current_state_fops);
+
+		debugfs_create_u32("base_units", 0444, dir,
+				   &nsensor->base_units);
+
+		debugfs_create_file("unit_modifier", 0444, dir,
+				    info, &unit_modifier_fops);
+
+		debugfs_create_file("current_reading", 0444, dir,
+				    info, &current_reading_fops);
+
+		if (is_new)
+			debugfs_create_u32("rate_units", 0444, dir,
+					   &nsensor->rate_units);
+	}
+
+	if (!pcount)
+		return;
+
+	entries = debugfs_create_dir("platform_events", debugfs);
+
+	for (i = 0; i < pcount; i++, pevents++) {
+		scnprintf(buf, sizeof(buf), "%u", i);
+		dir = debugfs_create_dir(buf, entries);
+
+		debugfs_create_file("name", 0444, dir,
+				    (void *)pevents->name,
+				    &basic_string_fops);
+
+		debugfs_create_file("description", 0444, dir,
+				    (void *)pevents->description,
+				    &basic_string_fops);
+
+		debugfs_create_file("source_namespace", 0444, dir,
+				    (void *)pevents->source_namespace,
+				    &basic_string_fops);
+
+		debugfs_create_file("source_class", 0444, dir,
+				    (void *)pevents->source_class,
+				    &basic_string_fops);
+
+		debugfs_create_u32("category", 0444, dir,
+				   &pevents->category);
+
+		debugfs_create_u32("possible_severity", 0444, dir,
+				   &pevents->possible_severity);
+
+		debugfs_create_u32("possible_status", 0444, dir,
+				   &pevents->possible_status);
+	}
+}
+
+static umode_t hp_wmi_hwmon_is_visible(const void *drvdata,
+				       enum hwmon_sensor_types type,
+				       u32 attr, int channel)
+{
+	const struct hp_wmi_sensors *state = drvdata;
+	const struct hp_wmi_info *info;
+
+	if (type == hwmon_intrusion)
+		return state->has_intrusion ? 0644 : 0;
+
+	if (!state->info_map[type] || !state->info_map[type][channel])
+		return 0;
+
+	info = state->info_map[type][channel];
+
+	if ((type == hwmon_temp && attr == hwmon_temp_alarm) ||
+	    (type == hwmon_fan  && attr == hwmon_fan_alarm))
+		return info->has_alarm ? 0444 : 0;
+
+	return 0444;
+}
+
+static int hp_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+			     u32 attr, int channel, long *out_val)
+{
+	struct hp_wmi_sensors *state = dev_get_drvdata(dev);
+	const struct hp_wmi_numeric_sensor *nsensor;
+	struct hp_wmi_info *info;
+	int err;
+
+	if (type == hwmon_intrusion) {
+		*out_val = state->intrusion ? 1 : 0;
+
+		return 0;
+	}
+
+	info = state->info_map[type][channel];
+
+	if ((type == hwmon_temp && attr == hwmon_temp_alarm) ||
+	    (type == hwmon_fan  && attr == hwmon_fan_alarm)) {
+		*out_val = info->alarm ? 1 : 0;
+		info->alarm = false;
+
+		return 0;
+	}
+
+	nsensor = &info->nsensor;
+
+	err = hp_wmi_update_info(state, info);
+	if (err)
+		return err;
+
+	if ((type == hwmon_temp && attr == hwmon_temp_fault) ||
+	    (type == hwmon_fan  && attr == hwmon_fan_fault))
+		*out_val = numeric_sensor_has_fault(nsensor);
+	else
+		*out_val = info->cached_val;
+
+	return 0;
+}
+
+static int hp_wmi_hwmon_read_string(struct device *dev,
+				    enum hwmon_sensor_types type, u32 attr,
+				    int channel, const char **out_str)
+{
+	const struct hp_wmi_sensors *state = dev_get_drvdata(dev);
+	const struct hp_wmi_info *info;
+
+	info = state->info_map[type][channel];
+	*out_str = info->nsensor.name;
+
+	return 0;
+}
+
+static int hp_wmi_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
+			      u32 attr, int channel, long val)
+{
+	struct hp_wmi_sensors *state = dev_get_drvdata(dev);
+
+	if (val)
+		return -EINVAL;
+
+	mutex_lock(&state->lock);
+
+	state->intrusion = false;
+
+	mutex_unlock(&state->lock);
+
+	return 0;
+}
+
+static const struct hwmon_ops hp_wmi_hwmon_ops = {
+	.is_visible  = hp_wmi_hwmon_is_visible,
+	.read	     = hp_wmi_hwmon_read,
+	.read_string = hp_wmi_hwmon_read_string,
+	.write	     = hp_wmi_hwmon_write,
+};
+
+static struct hwmon_chip_info hp_wmi_chip_info = {
+	.ops         = &hp_wmi_hwmon_ops,
+	.info        = NULL,
+};
+
+static struct hp_wmi_info *match_fan_event(struct hp_wmi_sensors *state,
+					   const char *event_description)
+{
+	struct hp_wmi_info **ptr_info = state->info_map[hwmon_fan];
+	u8 fan_count = state->channel_count[hwmon_fan];
+	struct hp_wmi_info *info;
+	const char *name;
+	u8 i;
+
+	/* Fan event has Description "X Speed". Sensor has Name "X[ Speed]". */
+
+	for (i = 0; i < fan_count; i++, ptr_info++) {
+		info = *ptr_info;
+		name = info->nsensor.name;
+
+		if (strstr(event_description, name))
+			return info;
+	}
+
+	return NULL;
+}
+
+static u8 match_temp_events(struct hp_wmi_sensors *state,
+			    const char *event_description,
+			    struct hp_wmi_info *temp_info[])
+{
+	struct hp_wmi_info **ptr_info = state->info_map[hwmon_temp];
+	u8 temp_count = state->channel_count[hwmon_temp];
+	struct hp_wmi_info *info;
+	const char *name;
+	u8 count = 0;
+	bool is_cpu;
+	bool is_sys;
+	u8 i;
+
+	/* Description is either "CPU Thermal Index" or "Chassis Thermal Index". */
+
+	is_cpu = !strcmp(event_description, HP_WMI_PATTERN_CPU_TEMP);
+	is_sys = !strcmp(event_description, HP_WMI_PATTERN_SYS_TEMP);
+	if (!is_cpu && !is_sys)
+		return 0;
+
+	/*
+	 * CPU event: Match one sensor with Name either "CPU Thermal Index" or
+	 * "CPU Temperature", or multiple with Name(s) "CPU[#] Temperature".
+	 *
+	 * Chassis event: Match one sensor with Name either
+	 * "Chassis Thermal Index" or "System Ambient Temperature".
+	 */
+
+	for (i = 0; i < temp_count; i++, ptr_info++) {
+		info = *ptr_info;
+		name = info->nsensor.name;
+
+		if ((is_cpu && (!strcmp(name, HP_WMI_PATTERN_CPU_TEMP) ||
+				!strcmp(name, HP_WMI_PATTERN_CPU_TEMP2))) ||
+		    (is_sys && (!strcmp(name, HP_WMI_PATTERN_SYS_TEMP) ||
+				!strcmp(name, HP_WMI_PATTERN_SYS_TEMP2)))) {
+			temp_info[0] = info;
+			return 1;
+		}
+
+		if (is_cpu && (strstr(name, HP_WMI_PATTERN_CPU) &&
+			       strstr(name, HP_WMI_PATTERN_TEMP)))
+			temp_info[count++] = info;
+	}
+
+	return count;
+}
+
+/* hp_wmi_devm_debugfs_remove - devm callback for WMI event handler removal */
+static void hp_wmi_devm_notify_remove(void *ignored)
+{
+	wmi_remove_notify_handler(HP_WMI_EVENT_GUID);
+}
+
+/* hp_wmi_notify - WMI event notification handler */
+static void hp_wmi_notify(u32 value, void *context)
+{
+	struct hp_wmi_info *temp_info[HP_WMI_MAX_INSTANCES] = {};
+	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct hp_wmi_sensors *state = context;
+	struct device *dev = &state->wdev->dev;
+	struct hp_wmi_info *fan_info;
+	struct hp_wmi_event event;
+	union acpi_object *wobj;
+	acpi_status err;
+	int event_type;
+	u8 count;
+
+	/*
+	 * The following warning may occur in the kernel log:
+	 *
+	 *   ACPI Warning: \_SB.WMID._WED: Return type mismatch -
+	 *     found Package, expected Integer/String/Buffer
+	 *
+	 * After using [4] to decode BMOF blobs found in [3], careless copying
+	 * of BIOS code seems the most likely explanation for this warning.
+	 * HP_WMI_EVENT_GUID refers to \\.\root\WMI\HPBIOS_BIOSEvent on
+	 * business-class systems, but it refers to \\.\root\WMI\hpqBEvnt on
+	 * non-business-class systems. Per the existing hp-wmi driver, it
+	 * looks like an instance of hpqBEvnt delivered as event data may
+	 * indeed take the form of a raw ACPI_BUFFER on non-business-class
+	 * systems ("may" because ASL shows some BIOSes do strange things).
+	 *
+	 * In any case, we can ignore this warning, because we always validate
+	 * the event data to ensure it is an ACPI_PACKAGE containing a
+	 * HPBIOS_BIOSEvent instance.
+	 */
+
+	mutex_lock(&state->lock);
+
+	err = wmi_get_event_data(value, &out);
+	if (ACPI_FAILURE(err))
+		goto out_unlock;
+
+	wobj = out.pointer;
+
+	err = populate_event_from_wobj(&event, wobj);
+	if (err) {
+		dev_warn(dev, "Bad event data (ACPI type %d)\n", wobj->type);
+		goto out_free_wobj;
+	}
+
+	event_type = classify_event(event.name, event.category);
+	switch (event_type) {
+	case HP_WMI_TYPE_AIR_FLOW:
+		fan_info = match_fan_event(state, event.description);
+		if (fan_info)
+			fan_info->alarm = true;
+		break;
+
+	case HP_WMI_TYPE_INTRUSION:
+		state->intrusion = true;
+		break;
+
+	case HP_WMI_TYPE_TEMPERATURE:
+		count = match_temp_events(state, event.description, temp_info);
+		while (count)
+			temp_info[--count]->alarm = true;
+		break;
+
+	default:
+		break;
+	}
+
+out_free_wobj:
+	kfree(wobj);
+
+out_unlock:
+	mutex_unlock(&state->lock);
+}
+
+static int init_platform_events(struct device *dev,
+				struct hp_wmi_platform_events **out_pevents,
+				u8 *out_pcount)
+{
+	struct hp_wmi_platform_events *pevents_arr;
+	struct hp_wmi_platform_events *pevents;
+	union acpi_object *wobj;
+	u8 count;
+	int err;
+	u8 i;
+
+	count = hp_wmi_wobj_instance_count(HP_WMI_PLATFORM_EVENTS_GUID);
+	if (!count) {
+		*out_pcount = 0;
+
+		dev_dbg(dev, "No platform events\n");
+
+		return 0;
+	}
+
+	pevents_arr = devm_kcalloc(dev, count, sizeof(*pevents), GFP_KERNEL);
+	if (!pevents_arr)
+		return -ENOMEM;
+
+	for (i = 0, pevents = pevents_arr; i < count; i++, pevents++) {
+		wobj = hp_wmi_get_wobj(HP_WMI_PLATFORM_EVENTS_GUID, i);
+		if (!wobj)
+			return -EIO;
+
+		err = populate_platform_events_from_wobj(dev, pevents, wobj);
+
+		kfree(wobj);
+
+		if (err)
+			return err;
+	}
+
+	*out_pevents = pevents_arr;
+	*out_pcount = count;
+
+	dev_dbg(dev, "Found %u platform events\n", count);
+
+	return 0;
+}
+
+static int init_numeric_sensors(struct hp_wmi_sensors *state,
+				struct hp_wmi_info *connected[],
+				struct hp_wmi_info **out_info,
+				u8 *out_icount, u8 *out_count,
+				bool *out_is_new)
+{
+	struct hp_wmi_info ***info_map = state->info_map;
+	u8 *channel_count = state->channel_count;
+	struct device *dev = &state->wdev->dev;
+	struct hp_wmi_numeric_sensor *nsensor;
+	u8 channel_index[hwmon_max] = {};
+	enum hwmon_sensor_types type;
+	struct hp_wmi_info *info_arr;
+	struct hp_wmi_info *info;
+	union acpi_object *wobj;
+	u8 count = 0;
+	bool is_new;
+	u8 icount;
+	int wtype;
+	int err;
+	u8 c;
+	u8 i;
+
+	icount = hp_wmi_wobj_instance_count(HP_WMI_NUMERIC_SENSOR_GUID);
+	if (!icount)
+		return -ENODATA;
+
+	info_arr = devm_kcalloc(dev, icount, sizeof(*info), GFP_KERNEL);
+	if (!info_arr)
+		return -ENOMEM;
+
+	for (i = 0, info = info_arr; i < icount; i++, info++) {
+		wobj = hp_wmi_get_wobj(HP_WMI_NUMERIC_SENSOR_GUID, i);
+		if (!wobj)
+			return -EIO;
+
+		info->instance = i;
+		info->state = state;
+		nsensor = &info->nsensor;
+
+		err = populate_numeric_sensor_from_wobj(dev, nsensor, wobj,
+							&is_new);
+
+		kfree(wobj);
+
+		if (err)
+			return err;
+
+		if (!numeric_sensor_is_connected(nsensor))
+			continue;
+
+		wtype = classify_numeric_sensor(nsensor);
+		if (wtype < 0)
+			continue;
+
+		type = hp_wmi_hwmon_type_map[wtype];
+
+		channel_count[type]++;
+
+		info->type = type;
+
+		interpret_info(info);
+
+		connected[count++] = info;
+	}
+
+	dev_dbg(dev, "Found %u sensors (%u connected)\n", i, count);
+
+	for (i = 0; i < count; i++) {
+		info = connected[i];
+		type = info->type;
+		c = channel_index[type]++;
+
+		if (!info_map[type]) {
+			info_map[type] = devm_kcalloc(dev, channel_count[type],
+						      sizeof(*info_map),
+						      GFP_KERNEL);
+			if (!info_map[type])
+				return -ENOMEM;
+		}
+
+		info_map[type][c] = info;
+	}
+
+	*out_info = info_arr;
+	*out_icount = icount;
+	*out_count = count;
+	*out_is_new = is_new;
+
+	return 0;
+}
+
+static bool find_event_attributes(struct hp_wmi_sensors *state,
+				  struct hp_wmi_platform_events *pevents,
+				  u8 pevents_count)
+{
+	/*
+	 * The existence of this HPBIOS_PlatformEvents instance:
+	 *
+	 *   {
+	 *     Name = "Rear Chassis Fan0 Stall";
+	 *     Description = "Rear Chassis Fan0 Speed";
+	 *     Category = 3;           // "Sensor"
+	 *     PossibleSeverity = 25;  // "Critical Failure"
+	 *     PossibleStatus = 5;     // "Predictive Failure"
+	 *     [...]
+	 *   }
+	 *
+	 * means that this HPBIOS_BIOSEvent instance may occur:
+	 *
+	 *   {
+	 *     Name = "Rear Chassis Fan0 Stall";
+	 *     Description = "Rear Chassis Fan0 Speed";
+	 *     Category = 3;           // "Sensor"
+	 *     Severity = 25;          // "Critical Failure"
+	 *     Status = 5;             // "Predictive Failure"
+	 *   }
+	 *
+	 * After the event occurs (e.g. because the fan was unplugged),
+	 * polling the related HPBIOS_BIOSNumericSensor instance gives:
+	 *
+	 *   {
+	 *      Name = "Rear Chassis Fan0";
+	 *      Description = "Reports rear chassis fan0 speed";
+	 *      OperationalStatus = 5; // "Predictive Failure", was 3 ("OK")
+	 *      CurrentReading = 0;
+	 *      [...]
+	 *   }
+	 *
+	 * In this example, the hwmon fan channel for "Rear Chassis Fan0"
+	 * should support the alarm flag and have it be set if the related
+	 * HPBIOS_BIOSEvent instance occurs.
+	 *
+	 * In addition to fan events, temperature (CPU/chassis) and intrusion
+	 * events are relevant to hwmon [2]. Note that much information in [2]
+	 * is unreliable; it is referenced in addition to ACPI dumps [3] merely
+	 * to support the conclusion that sensor and event names/descriptions
+	 * are systematic enough to allow this driver to match them.
+	 *
+	 * Complications and limitations:
+	 *
+	 * - Strings are freeform and may vary, cf. sensor Name "CPU0 Fan"
+	 *   on a Z420 vs. "CPU Fan Speed" on an EliteOne 800 G1.
+	 * - Leading/trailing whitespace is a rare but real possibility [3].
+	 * - The HPBIOS_PlatformEvents object may not exist or its instances
+	 *   may show that the system only has e.g. BIOS setting-related
+	 *   events (cf. the ProBook 4540s and ProBook 470 G0 [3]).
+	 */
+
+	struct hp_wmi_info *temp_info[HP_WMI_MAX_INSTANCES] = {};
+	const char *event_description;
+	struct hp_wmi_info *fan_info;
+	bool has_events = false;
+	const char *event_name;
+	u32 event_category;
+	int event_type;
+	u8 count;
+	u8 i;
+
+	for (i = 0; i < pevents_count; i++, pevents++) {
+		event_name = pevents->name;
+		event_description = pevents->description;
+		event_category = pevents->category;
+
+		event_type = classify_event(event_name, event_category);
+		switch (event_type) {
+		case HP_WMI_TYPE_AIR_FLOW:
+			fan_info = match_fan_event(state, event_description);
+			if (!fan_info)
+				break;
+
+			fan_info->has_alarm = true;
+			has_events = true;
+			break;
+
+		case HP_WMI_TYPE_INTRUSION:
+			state->has_intrusion = true;
+			has_events = true;
+			break;
+
+		case HP_WMI_TYPE_TEMPERATURE:
+			count = match_temp_events(state, event_description,
+						  temp_info);
+			if (!count)
+				break;
+
+			while (count)
+				temp_info[--count]->has_alarm = true;
+			has_events = true;
+			break;
+
+		default:
+			break;
+		}
+	}
+
+	return has_events;
+}
+
+static int make_chip_info(struct hp_wmi_sensors *state, bool has_events)
+{
+	const struct hwmon_channel_info **ptr_channel_info;
+	struct hp_wmi_info ***info_map = state->info_map;
+	u8 *channel_count = state->channel_count;
+	struct hwmon_channel_info *channel_info;
+	struct device *dev = &state->wdev->dev;
+	enum hwmon_sensor_types type;
+	u8 type_count = 0;
+	u32 *config;
+	u32 attr;
+	u8 count;
+	u8 i;
+
+	if (channel_count[hwmon_temp])
+		channel_count[hwmon_chip] = 1;
+
+	if (has_events && state->has_intrusion)
+		channel_count[hwmon_intrusion] = 1;
+
+	for (type = hwmon_chip; type < hwmon_max; type++)
+		if (channel_count[type])
+			type_count++;
+
+	channel_info = devm_kcalloc(dev, type_count,
+				    sizeof(*channel_info), GFP_KERNEL);
+	if (!channel_info)
+		return -ENOMEM;
+
+	ptr_channel_info = devm_kcalloc(dev, type_count + 1,
+					sizeof(*ptr_channel_info), GFP_KERNEL);
+	if (!ptr_channel_info)
+		return -ENOMEM;
+
+	hp_wmi_chip_info.info = ptr_channel_info;
+
+	for (type = hwmon_chip; type < hwmon_max; type++) {
+		count = channel_count[type];
+		if (!count)
+			continue;
+
+		config = devm_kcalloc(dev, count + 1,
+				      sizeof(*config), GFP_KERNEL);
+		if (!config)
+			return -ENOMEM;
+
+		attr = hp_wmi_hwmon_attributes[type];
+		channel_info->type = type;
+		channel_info->config = config;
+		memset32(config, attr, count);
+
+		*ptr_channel_info++ = channel_info++;
+
+		if (!has_events || (type != hwmon_temp && type != hwmon_fan))
+			continue;
+
+		attr = type == hwmon_temp ? HWMON_T_ALARM : HWMON_F_ALARM;
+
+		for (i = 0; i < count; i++)
+			if (info_map[type][i]->has_alarm)
+				config[i] |= attr;
+	}
+
+	return 0;
+}
+
+static bool add_event_handler(struct hp_wmi_sensors *state)
+{
+	struct device *dev = &state->wdev->dev;
+	int err;
+
+	err = wmi_install_notify_handler(HP_WMI_EVENT_GUID,
+					 hp_wmi_notify, state);
+	if (err) {
+		dev_info(dev, "Failed to subscribe to WMI event\n");
+		return false;
+	}
+
+	err = devm_add_action_or_reset(dev, hp_wmi_devm_notify_remove, NULL);
+	if (err)
+		return false;
+
+	return true;
+}
+
+static int hp_wmi_sensors_init(struct hp_wmi_sensors *state)
+{
+	struct hp_wmi_info *connected[HP_WMI_MAX_INSTANCES];
+	struct hp_wmi_platform_events *pevents = NULL;
+	struct device *dev = &state->wdev->dev;
+	struct hp_wmi_info *info;
+	struct device *hwdev;
+	bool has_events;
+	bool is_new;
+	u8 icount;
+	u8 pcount;
+	u8 count;
+	int err;
+
+	err = init_platform_events(dev, &pevents, &pcount);
+	if (err)
+		return err;
+
+	err = init_numeric_sensors(state, connected, &info,
+				   &icount, &count, &is_new);
+	if (err)
+		return err;
+
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		hp_wmi_debugfs_init(dev, info, pevents, icount, pcount, is_new);
+
+	if (!count)
+		return 0;	/* No connected sensors; debugfs only. */
+
+	has_events = find_event_attributes(state, pevents, pcount);
+
+	/* Survive failure to install WMI event handler. */
+	if (has_events && !add_event_handler(state))
+		has_events = false;
+
+	err = make_chip_info(state, has_events);
+	if (err)
+		return err;
+
+	hwdev = devm_hwmon_device_register_with_info(dev, "hp_wmi_sensors",
+						     state, &hp_wmi_chip_info,
+						     NULL);
+	return PTR_ERR_OR_ZERO(hwdev);
+}
+
+static int hp_wmi_sensors_probe(struct wmi_device *wdev, const void *context)
+{
+	struct device *dev = &wdev->dev;
+	struct hp_wmi_sensors *state;
+
+	state = devm_kzalloc(dev, sizeof(*state), GFP_KERNEL);
+	if (!state)
+		return -ENOMEM;
+
+	state->wdev = wdev;
+
+	mutex_init(&state->lock);
+
+	dev_set_drvdata(dev, state);
+
+	return hp_wmi_sensors_init(state);
+}
+
+static const struct wmi_device_id hp_wmi_sensors_id_table[] = {
+	{ HP_WMI_NUMERIC_SENSOR_GUID, NULL },
+	{},
+};
+
+static struct wmi_driver hp_wmi_sensors_driver = {
+	.driver   = { .name = "hp-wmi-sensors" },
+	.id_table = hp_wmi_sensors_id_table,
+	.probe    = hp_wmi_sensors_probe,
+};
+module_wmi_driver(hp_wmi_sensors_driver);
+
+MODULE_AUTHOR("James Seo <james@equiv.tech>");
+MODULE_DESCRIPTION("HP WMI Sensors driver");
+MODULE_LICENSE("GPL");