xref: /linux/drivers/hwmon/hp-wmi-sensors.c (revision 56d8b784c56588cd40f98e4b1d4f6e29e3cb02b8)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * hwmon driver for HP (and some HP Compaq) business-class computers that
4  * report numeric sensor data via Windows Management Instrumentation (WMI).
5  *
6  * Copyright (C) 2023 James Seo <james@equiv.tech>
7  *
8  * References:
9  * [1] Hewlett-Packard Development Company, L.P.,
10  *     "HP Client Management Interface Technical White Paper", 2005. [Online].
11  *     Available: https://h20331.www2.hp.com/hpsub/downloads/cmi_whitepaper.pdf
12  * [2] Hewlett-Packard Development Company, L.P.,
13  *     "HP Retail Manageability", 2012. [Online].
14  *     Available: http://h10032.www1.hp.com/ctg/Manual/c03291135.pdf
15  * [3] Linux Hardware Project, A. Ponomarenko et al.,
16  *     "linuxhw/ACPI - Collect ACPI table dumps", 2018. [Online].
17  *     Available: https://github.com/linuxhw/ACPI
18  * [4] P. Rohár, "bmfdec - Decompile binary MOF file (BMF) from WMI buffer",
19  *     2017. [Online]. Available: https://github.com/pali/bmfdec
20  * [5] Microsoft Corporation, "Driver-Defined WMI Data Items", 2017. [Online].
21  *     Available: https://learn.microsoft.com/en-us/windows-hardware/drivers/kernel/driver-defined-wmi-data-items
22  */
23 
24 #include <linux/acpi.h>
25 #include <linux/debugfs.h>
26 #include <linux/hwmon.h>
27 #include <linux/jiffies.h>
28 #include <linux/mutex.h>
29 #include <linux/nls.h>
30 #include <linux/units.h>
31 #include <linux/wmi.h>
32 
33 #define HP_WMI_EVENT_NAMESPACE		"root\\WMI"
34 #define HP_WMI_EVENT_CLASS		"HPBIOS_BIOSEvent"
35 #define HP_WMI_EVENT_GUID		"95F24279-4D7B-4334-9387-ACCDC67EF61C"
36 #define HP_WMI_NUMERIC_SENSOR_GUID	"8F1F6435-9F42-42C8-BADC-0E9424F20C9A"
37 #define HP_WMI_PLATFORM_EVENTS_GUID	"41227C2D-80E1-423F-8B8E-87E32755A0EB"
38 
39 /* Patterns for recognizing sensors and matching events to channels. */
40 
41 #define HP_WMI_PATTERN_SYS_TEMP		"Chassis Thermal Index"
42 #define HP_WMI_PATTERN_SYS_TEMP2	"System Ambient Temperature"
43 #define HP_WMI_PATTERN_CPU_TEMP		"CPU Thermal Index"
44 #define HP_WMI_PATTERN_CPU_TEMP2	"CPU Temperature"
45 #define HP_WMI_PATTERN_TEMP_SENSOR	"Thermal Index"
46 #define HP_WMI_PATTERN_TEMP_ALARM	"Thermal Critical"
47 #define HP_WMI_PATTERN_INTRUSION_ALARM	"Hood Intrusion"
48 #define HP_WMI_PATTERN_FAN_ALARM	"Stall"
49 #define HP_WMI_PATTERN_TEMP		"Temperature"
50 #define HP_WMI_PATTERN_CPU		"CPU"
51 
52 /* These limits are arbitrary. The WMI implementation may vary by system. */
53 
54 #define HP_WMI_MAX_STR_SIZE		128U
55 #define HP_WMI_MAX_PROPERTIES		32U
56 #define HP_WMI_MAX_INSTANCES		32U
57 
58 enum hp_wmi_type {
59 	HP_WMI_TYPE_OTHER			= 1,
60 	HP_WMI_TYPE_TEMPERATURE			= 2,
61 	HP_WMI_TYPE_VOLTAGE			= 3,
62 	HP_WMI_TYPE_CURRENT			= 4,
63 	HP_WMI_TYPE_AIR_FLOW			= 12,
64 	HP_WMI_TYPE_INTRUSION			= 0xabadb01, /* Custom. */
65 };
66 
67 enum hp_wmi_category {
68 	HP_WMI_CATEGORY_SENSOR			= 3,
69 };
70 
71 enum hp_wmi_severity {
72 	HP_WMI_SEVERITY_UNKNOWN			= 0,
73 	HP_WMI_SEVERITY_OK			= 5,
74 	HP_WMI_SEVERITY_DEGRADED_WARNING	= 10,
75 	HP_WMI_SEVERITY_MINOR_FAILURE		= 15,
76 	HP_WMI_SEVERITY_MAJOR_FAILURE		= 20,
77 	HP_WMI_SEVERITY_CRITICAL_FAILURE	= 25,
78 	HP_WMI_SEVERITY_NON_RECOVERABLE_ERROR	= 30,
79 };
80 
81 enum hp_wmi_status {
82 	HP_WMI_STATUS_OK			= 2,
83 	HP_WMI_STATUS_DEGRADED			= 3,
84 	HP_WMI_STATUS_STRESSED			= 4,
85 	HP_WMI_STATUS_PREDICTIVE_FAILURE	= 5,
86 	HP_WMI_STATUS_ERROR			= 6,
87 	HP_WMI_STATUS_NON_RECOVERABLE_ERROR	= 7,
88 	HP_WMI_STATUS_NO_CONTACT		= 12,
89 	HP_WMI_STATUS_LOST_COMMUNICATION	= 13,
90 	HP_WMI_STATUS_ABORTED			= 14,
91 	HP_WMI_STATUS_SUPPORTING_ENTITY_IN_ERROR = 16,
92 
93 	/* Occurs combined with one of "OK", "Degraded", and "Error" [1]. */
94 	HP_WMI_STATUS_COMPLETED			= 17,
95 };
96 
97 enum hp_wmi_units {
98 	HP_WMI_UNITS_OTHER			= 1,
99 	HP_WMI_UNITS_DEGREES_C			= 2,
100 	HP_WMI_UNITS_DEGREES_F			= 3,
101 	HP_WMI_UNITS_DEGREES_K			= 4,
102 	HP_WMI_UNITS_VOLTS			= 5,
103 	HP_WMI_UNITS_AMPS			= 6,
104 	HP_WMI_UNITS_RPM			= 19,
105 };
106 
107 enum hp_wmi_property {
108 	HP_WMI_PROPERTY_NAME			= 0,
109 	HP_WMI_PROPERTY_DESCRIPTION		= 1,
110 	HP_WMI_PROPERTY_SENSOR_TYPE		= 2,
111 	HP_WMI_PROPERTY_OTHER_SENSOR_TYPE	= 3,
112 	HP_WMI_PROPERTY_OPERATIONAL_STATUS	= 4,
113 	HP_WMI_PROPERTY_SIZE			= 5,
114 	HP_WMI_PROPERTY_POSSIBLE_STATES		= 6,
115 	HP_WMI_PROPERTY_CURRENT_STATE		= 7,
116 	HP_WMI_PROPERTY_BASE_UNITS		= 8,
117 	HP_WMI_PROPERTY_UNIT_MODIFIER		= 9,
118 	HP_WMI_PROPERTY_CURRENT_READING		= 10,
119 	HP_WMI_PROPERTY_RATE_UNITS		= 11,
120 };
121 
122 static const acpi_object_type hp_wmi_property_map[] = {
123 	[HP_WMI_PROPERTY_NAME]			= ACPI_TYPE_STRING,
124 	[HP_WMI_PROPERTY_DESCRIPTION]		= ACPI_TYPE_STRING,
125 	[HP_WMI_PROPERTY_SENSOR_TYPE]		= ACPI_TYPE_INTEGER,
126 	[HP_WMI_PROPERTY_OTHER_SENSOR_TYPE]	= ACPI_TYPE_STRING,
127 	[HP_WMI_PROPERTY_OPERATIONAL_STATUS]	= ACPI_TYPE_INTEGER,
128 	[HP_WMI_PROPERTY_SIZE]			= ACPI_TYPE_INTEGER,
129 	[HP_WMI_PROPERTY_POSSIBLE_STATES]	= ACPI_TYPE_STRING,
130 	[HP_WMI_PROPERTY_CURRENT_STATE]		= ACPI_TYPE_STRING,
131 	[HP_WMI_PROPERTY_BASE_UNITS]		= ACPI_TYPE_INTEGER,
132 	[HP_WMI_PROPERTY_UNIT_MODIFIER]		= ACPI_TYPE_INTEGER,
133 	[HP_WMI_PROPERTY_CURRENT_READING]	= ACPI_TYPE_INTEGER,
134 	[HP_WMI_PROPERTY_RATE_UNITS]		= ACPI_TYPE_INTEGER,
135 };
136 
137 enum hp_wmi_platform_events_property {
138 	HP_WMI_PLATFORM_EVENTS_PROPERTY_NAME		    = 0,
139 	HP_WMI_PLATFORM_EVENTS_PROPERTY_DESCRIPTION	    = 1,
140 	HP_WMI_PLATFORM_EVENTS_PROPERTY_SOURCE_NAMESPACE    = 2,
141 	HP_WMI_PLATFORM_EVENTS_PROPERTY_SOURCE_CLASS	    = 3,
142 	HP_WMI_PLATFORM_EVENTS_PROPERTY_CATEGORY	    = 4,
143 	HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_SEVERITY   = 5,
144 	HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_STATUS	    = 6,
145 };
146 
147 static const acpi_object_type hp_wmi_platform_events_property_map[] = {
148 	[HP_WMI_PLATFORM_EVENTS_PROPERTY_NAME]		    = ACPI_TYPE_STRING,
149 	[HP_WMI_PLATFORM_EVENTS_PROPERTY_DESCRIPTION]	    = ACPI_TYPE_STRING,
150 	[HP_WMI_PLATFORM_EVENTS_PROPERTY_SOURCE_NAMESPACE]  = ACPI_TYPE_STRING,
151 	[HP_WMI_PLATFORM_EVENTS_PROPERTY_SOURCE_CLASS]	    = ACPI_TYPE_STRING,
152 	[HP_WMI_PLATFORM_EVENTS_PROPERTY_CATEGORY]	    = ACPI_TYPE_INTEGER,
153 	[HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_SEVERITY] = ACPI_TYPE_INTEGER,
154 	[HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_STATUS]   = ACPI_TYPE_INTEGER,
155 };
156 
157 enum hp_wmi_event_property {
158 	HP_WMI_EVENT_PROPERTY_NAME		= 0,
159 	HP_WMI_EVENT_PROPERTY_DESCRIPTION	= 1,
160 	HP_WMI_EVENT_PROPERTY_CATEGORY		= 2,
161 	HP_WMI_EVENT_PROPERTY_SEVERITY		= 3,
162 	HP_WMI_EVENT_PROPERTY_STATUS		= 4,
163 };
164 
165 static const acpi_object_type hp_wmi_event_property_map[] = {
166 	[HP_WMI_EVENT_PROPERTY_NAME]		= ACPI_TYPE_STRING,
167 	[HP_WMI_EVENT_PROPERTY_DESCRIPTION]	= ACPI_TYPE_STRING,
168 	[HP_WMI_EVENT_PROPERTY_CATEGORY]	= ACPI_TYPE_INTEGER,
169 	[HP_WMI_EVENT_PROPERTY_SEVERITY]	= ACPI_TYPE_INTEGER,
170 	[HP_WMI_EVENT_PROPERTY_STATUS]		= ACPI_TYPE_INTEGER,
171 };
172 
173 static const enum hwmon_sensor_types hp_wmi_hwmon_type_map[] = {
174 	[HP_WMI_TYPE_TEMPERATURE]		= hwmon_temp,
175 	[HP_WMI_TYPE_VOLTAGE]			= hwmon_in,
176 	[HP_WMI_TYPE_CURRENT]			= hwmon_curr,
177 	[HP_WMI_TYPE_AIR_FLOW]			= hwmon_fan,
178 };
179 
180 static const u32 hp_wmi_hwmon_attributes[hwmon_max] = {
181 	[hwmon_chip]	  = HWMON_C_REGISTER_TZ,
182 	[hwmon_temp]	  = HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_FAULT,
183 	[hwmon_in]	  = HWMON_I_INPUT | HWMON_I_LABEL,
184 	[hwmon_curr]	  = HWMON_C_INPUT | HWMON_C_LABEL,
185 	[hwmon_fan]	  = HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_FAULT,
186 	[hwmon_intrusion] = HWMON_INTRUSION_ALARM,
187 };
188 
189 /*
190  * struct hp_wmi_numeric_sensor - a HPBIOS_BIOSNumericSensor instance
191  *
192  * Two variants of HPBIOS_BIOSNumericSensor are known. The first is specified
193  * in [1] and appears to be much more widespread. The second was discovered by
194  * decoding BMOF blobs [4], seems to be found only in some newer ZBook systems
195  * [3], and has two new properties and a slightly different property order.
196  *
197  * These differences don't matter on Windows, where WMI object properties are
198  * accessed by name. For us, supporting both variants gets ugly and hacky at
199  * times. The fun begins now; this struct is defined as per the new variant.
200  *
201  * Effective MOF definition:
202  *
203  *   #pragma namespace("\\\\.\\root\\HP\\InstrumentedBIOS");
204  *   class HPBIOS_BIOSNumericSensor {
205  *     [read] string Name;
206  *     [read] string Description;
207  *     [read, ValueMap {"0","1","2","3","4","5","6","7","8","9",
208  *      "10","11","12"}, Values {"Unknown","Other","Temperature",
209  *      "Voltage","Current","Tachometer","Counter","Switch","Lock",
210  *      "Humidity","Smoke Detection","Presence","Air Flow"}]
211  *     uint32 SensorType;
212  *     [read] string OtherSensorType;
213  *     [read, ValueMap {"0","1","2","3","4","5","6","7","8","9",
214  *      "10","11","12","13","14","15","16","17","18","..",
215  *      "0x8000.."}, Values {"Unknown","Other","OK","Degraded",
216  *      "Stressed","Predictive Failure","Error",
217  *      "Non-Recoverable Error","Starting","Stopping","Stopped",
218  *      "In Service","No Contact","Lost Communication","Aborted",
219  *      "Dormant","Supporting Entity in Error","Completed",
220  *      "Power Mode","DMTF Reserved","Vendor Reserved"}]
221  *     uint32 OperationalStatus;
222  *     [read] uint32 Size;
223  *     [read] string PossibleStates[];
224  *     [read] string CurrentState;
225  *     [read, ValueMap {"0","1","2","3","4","5","6","7","8","9",
226  *      "10","11","12","13","14","15","16","17","18","19","20",
227  *      "21","22","23","24","25","26","27","28","29","30","31",
228  *      "32","33","34","35","36","37","38","39","40","41","42",
229  *      "43","44","45","46","47","48","49","50","51","52","53",
230  *      "54","55","56","57","58","59","60","61","62","63","64",
231  *      "65"}, Values {"Unknown","Other","Degrees C","Degrees F",
232  *      "Degrees K","Volts","Amps","Watts","Joules","Coulombs",
233  *      "VA","Nits","Lumens","Lux","Candelas","kPa","PSI",
234  *      "Newtons","CFM","RPM","Hertz","Seconds","Minutes",
235  *      "Hours","Days","Weeks","Mils","Inches","Feet",
236  *      "Cubic Inches","Cubic Feet","Meters","Cubic Centimeters",
237  *      "Cubic Meters","Liters","Fluid Ounces","Radians",
238  *      "Steradians","Revolutions","Cycles","Gravities","Ounces",
239  *      "Pounds","Foot-Pounds","Ounce-Inches","Gauss","Gilberts",
240  *      "Henries","Farads","Ohms","Siemens","Moles","Becquerels",
241  *      "PPM (parts/million)","Decibels","DbA","DbC","Grays",
242  *      "Sieverts","Color Temperature Degrees K","Bits","Bytes",
243  *      "Words (data)","DoubleWords","QuadWords","Percentage"}]
244  *     uint32 BaseUnits;
245  *     [read] sint32 UnitModifier;
246  *     [read] uint32 CurrentReading;
247  *     [read] uint32 RateUnits;
248  *   };
249  *
250  * Effective MOF definition of old variant [1] (sans redundant info):
251  *
252  *   class HPBIOS_BIOSNumericSensor {
253  *     [read] string Name;
254  *     [read] string Description;
255  *     [read] uint32 SensorType;
256  *     [read] string OtherSensorType;
257  *     [read] uint32 OperationalStatus;
258  *     [read] string CurrentState;
259  *     [read] string PossibleStates[];
260  *     [read] uint32 BaseUnits;
261  *     [read] sint32 UnitModifier;
262  *     [read] uint32 CurrentReading;
263  *   };
264  */
265 struct hp_wmi_numeric_sensor {
266 	const char *name;
267 	const char *description;
268 	u32 sensor_type;
269 	const char *other_sensor_type;	/* Explains "Other" SensorType. */
270 	u32 operational_status;
271 	u8 size;			/* Count of PossibleStates[]. */
272 	const char **possible_states;
273 	const char *current_state;
274 	u32 base_units;
275 	s32 unit_modifier;
276 	u32 current_reading;
277 	u32 rate_units;
278 };
279 
280 /*
281  * struct hp_wmi_platform_events - a HPBIOS_PlatformEvents instance
282  *
283  * Instances of this object reveal the set of possible HPBIOS_BIOSEvent
284  * instances for the current system, but it may not always be present.
285  *
286  * Effective MOF definition:
287  *
288  *   #pragma namespace("\\\\.\\root\\HP\\InstrumentedBIOS");
289  *   class HPBIOS_PlatformEvents {
290  *     [read] string Name;
291  *     [read] string Description;
292  *     [read] string SourceNamespace;
293  *     [read] string SourceClass;
294  *     [read, ValueMap {"0","1","2","3","4",".."}, Values {
295  *      "Unknown","Configuration Change","Button Pressed",
296  *      "Sensor","BIOS Settings","Reserved"}]
297  *     uint32 Category;
298  *     [read, ValueMap{"0","5","10","15","20","25","30",".."},
299  *      Values{"Unknown","OK","Degraded/Warning","Minor Failure",
300  *      "Major Failure","Critical Failure","Non-recoverable Error",
301  *      "DMTF Reserved"}]
302  *     uint32 PossibleSeverity;
303  *     [read, ValueMap {"0","1","2","3","4","5","6","7","8","9",
304  *      "10","11","12","13","14","15","16","17","18","..",
305  *      "0x8000.."}, Values {"Unknown","Other","OK","Degraded",
306  *      "Stressed","Predictive Failure","Error",
307  *      "Non-Recoverable Error","Starting","Stopping","Stopped",
308  *      "In Service","No Contact","Lost Communication","Aborted",
309  *      "Dormant","Supporting Entity in Error","Completed",
310  *      "Power Mode","DMTF Reserved","Vendor Reserved"}]
311  *     uint32 PossibleStatus;
312  *   };
313  */
314 struct hp_wmi_platform_events {
315 	const char *name;
316 	const char *description;
317 	const char *source_namespace;
318 	const char *source_class;
319 	u32 category;
320 	u32 possible_severity;
321 	u32 possible_status;
322 };
323 
324 /*
325  * struct hp_wmi_event - a HPBIOS_BIOSEvent instance
326  *
327  * Effective MOF definition [1] (corrected below from original):
328  *
329  *   #pragma namespace("\\\\.\\root\\WMI");
330  *   class HPBIOS_BIOSEvent : WMIEvent {
331  *     [read] string Name;
332  *     [read] string Description;
333  *     [read ValueMap {"0","1","2","3","4"}, Values {"Unknown",
334  *      "Configuration Change","Button Pressed","Sensor",
335  *      "BIOS Settings"}]
336  *     uint32 Category;
337  *     [read, ValueMap {"0","5","10","15","20","25","30"},
338  *      Values {"Unknown","OK","Degraded/Warning",
339  *      "Minor Failure","Major Failure","Critical Failure",
340  *      "Non-recoverable Error"}]
341  *     uint32 Severity;
342  *     [read, ValueMap {"0","1","2","3","4","5","6","7","8",
343  *      "9","10","11","12","13","14","15","16","17","18","..",
344  *      "0x8000.."}, Values {"Unknown","Other","OK","Degraded",
345  *      "Stressed","Predictive Failure","Error",
346  *      "Non-Recoverable Error","Starting","Stopping","Stopped",
347  *      "In Service","No Contact","Lost Communication","Aborted",
348  *      "Dormant","Supporting Entity in Error","Completed",
349  *      "Power Mode","DMTF Reserved","Vendor Reserved"}]
350  *     uint32 Status;
351  *   };
352  */
353 struct hp_wmi_event {
354 	const char *name;
355 	const char *description;
356 	u32 category;
357 };
358 
359 /*
360  * struct hp_wmi_info - sensor info
361  * @nsensor: numeric sensor properties
362  * @instance: its WMI instance number
363  * @state: pointer to driver state
364  * @has_alarm: whether sensor has an alarm flag
365  * @alarm: alarm flag
366  * @type: its hwmon sensor type
367  * @cached_val: current sensor reading value, scaled for hwmon
368  * @last_updated: when these readings were last updated
369  */
370 struct hp_wmi_info {
371 	struct hp_wmi_numeric_sensor nsensor;
372 	u8 instance;
373 	void *state;			/* void *: Avoid forward declaration. */
374 	bool has_alarm;
375 	bool alarm;
376 	enum hwmon_sensor_types type;
377 	long cached_val;
378 	unsigned long last_updated;	/* In jiffies. */
379 
380 };
381 
382 /*
383  * struct hp_wmi_sensors - driver state
384  * @wdev: pointer to the parent WMI device
385  * @info_map: sensor info structs by hwmon type and channel number
386  * @channel_count: count of hwmon channels by hwmon type
387  * @has_intrusion: whether an intrusion sensor is present
388  * @intrusion: intrusion flag
389  * @lock: mutex to lock polling WMI and changes to driver state
390  */
391 struct hp_wmi_sensors {
392 	struct wmi_device *wdev;
393 	struct hp_wmi_info **info_map[hwmon_max];
394 	u8 channel_count[hwmon_max];
395 	bool has_intrusion;
396 	bool intrusion;
397 
398 	struct mutex lock;	/* Lock polling WMI and driver state changes. */
399 };
400 
401 static bool is_raw_wmi_string(const u8 *pointer, u32 length)
402 {
403 	const u16 *ptr;
404 	u16 len;
405 
406 	/* WMI strings are length-prefixed UTF-16 [5]. */
407 	if (length <= sizeof(*ptr))
408 		return false;
409 
410 	length -= sizeof(*ptr);
411 	ptr = (const u16 *)pointer;
412 	len = *ptr;
413 
414 	return len <= length && !(len & 1);
415 }
416 
417 static char *convert_raw_wmi_string(const u8 *buf)
418 {
419 	const wchar_t *src;
420 	unsigned int cps;
421 	unsigned int len;
422 	char *dst;
423 	int i;
424 
425 	src = (const wchar_t *)buf;
426 
427 	/* Count UTF-16 code points. Exclude trailing null padding. */
428 	cps = *src / sizeof(*src);
429 	while (cps && !src[cps])
430 		cps--;
431 
432 	/* Each code point becomes up to 3 UTF-8 characters. */
433 	len = min(cps * 3, HP_WMI_MAX_STR_SIZE - 1);
434 
435 	dst = kmalloc((len + 1) * sizeof(*dst), GFP_KERNEL);
436 	if (!dst)
437 		return NULL;
438 
439 	i = utf16s_to_utf8s(++src, cps, UTF16_LITTLE_ENDIAN, dst, len);
440 	dst[i] = '\0';
441 
442 	return dst;
443 }
444 
445 /* hp_wmi_strdup - devm_kstrdup, but length-limited */
446 static char *hp_wmi_strdup(struct device *dev, const char *src)
447 {
448 	char *dst;
449 	size_t len;
450 
451 	len = strnlen(src, HP_WMI_MAX_STR_SIZE - 1);
452 
453 	dst = devm_kmalloc(dev, (len + 1) * sizeof(*dst), GFP_KERNEL);
454 	if (!dst)
455 		return NULL;
456 
457 	strscpy(dst, src, len + 1);
458 
459 	return dst;
460 }
461 
462 /* hp_wmi_wstrdup - hp_wmi_strdup, but for a raw WMI string */
463 static char *hp_wmi_wstrdup(struct device *dev, const u8 *buf)
464 {
465 	char *src;
466 	char *dst;
467 
468 	src = convert_raw_wmi_string(buf);
469 	if (!src)
470 		return NULL;
471 
472 	dst = hp_wmi_strdup(dev, strim(src));	/* Note: Copy is trimmed. */
473 
474 	kfree(src);
475 
476 	return dst;
477 }
478 
479 /*
480  * hp_wmi_get_wobj - poll WMI for a WMI object instance
481  * @guid: WMI object GUID
482  * @instance: WMI object instance number
483  *
484  * Returns a new WMI object instance on success, or NULL on error.
485  * Caller must kfree() the result.
486  */
487 static union acpi_object *hp_wmi_get_wobj(const char *guid, u8 instance)
488 {
489 	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
490 	acpi_status err;
491 
492 	err = wmi_query_block(guid, instance, &out);
493 	if (ACPI_FAILURE(err))
494 		return NULL;
495 
496 	return out.pointer;
497 }
498 
499 /* hp_wmi_wobj_instance_count - find count of WMI object instances */
500 static u8 hp_wmi_wobj_instance_count(const char *guid)
501 {
502 	int count;
503 
504 	count = wmi_instance_count(guid);
505 
506 	return clamp(count, 0, (int)HP_WMI_MAX_INSTANCES);
507 }
508 
509 static int check_wobj(const union acpi_object *wobj,
510 		      const acpi_object_type property_map[], int last_prop)
511 {
512 	acpi_object_type type = wobj->type;
513 	acpi_object_type valid_type;
514 	union acpi_object *elements;
515 	u32 elem_count;
516 	int prop;
517 
518 	if (type != ACPI_TYPE_PACKAGE)
519 		return -EINVAL;
520 
521 	elem_count = wobj->package.count;
522 	if (elem_count != last_prop + 1)
523 		return -EINVAL;
524 
525 	elements = wobj->package.elements;
526 	for (prop = 0; prop <= last_prop; prop++) {
527 		type = elements[prop].type;
528 		valid_type = property_map[prop];
529 		if (type != valid_type) {
530 			if (type == ACPI_TYPE_BUFFER &&
531 			    valid_type == ACPI_TYPE_STRING &&
532 			    is_raw_wmi_string(elements[prop].buffer.pointer,
533 					      elements[prop].buffer.length))
534 				continue;
535 			return -EINVAL;
536 		}
537 	}
538 
539 	return 0;
540 }
541 
542 static int extract_acpi_value(struct device *dev,
543 			      union acpi_object *element,
544 			      acpi_object_type type,
545 			      u32 *out_value, char **out_string)
546 {
547 	switch (type) {
548 	case ACPI_TYPE_INTEGER:
549 		*out_value = element->integer.value;
550 		break;
551 
552 	case ACPI_TYPE_STRING:
553 		*out_string = element->type == ACPI_TYPE_BUFFER ?
554 			hp_wmi_wstrdup(dev, element->buffer.pointer) :
555 			hp_wmi_strdup(dev, strim(element->string.pointer));
556 		if (!*out_string)
557 			return -ENOMEM;
558 		break;
559 
560 	default:
561 		return -EINVAL;
562 	}
563 
564 	return 0;
565 }
566 
567 /*
568  * check_numeric_sensor_wobj - validate a HPBIOS_BIOSNumericSensor instance
569  * @wobj: pointer to WMI object instance to check
570  * @out_size: out pointer to count of possible states
571  * @out_is_new: out pointer to whether this is a "new" variant object
572  *
573  * Returns 0 on success, or a negative error code on error.
574  */
575 static int check_numeric_sensor_wobj(const union acpi_object *wobj,
576 				     u8 *out_size, bool *out_is_new)
577 {
578 	acpi_object_type type = wobj->type;
579 	int prop = HP_WMI_PROPERTY_NAME;
580 	acpi_object_type valid_type;
581 	union acpi_object *elements;
582 	u32 elem_count;
583 	int last_prop;
584 	bool is_new;
585 	u8 count;
586 	u32 j;
587 	u32 i;
588 
589 	if (type != ACPI_TYPE_PACKAGE)
590 		return -EINVAL;
591 
592 	/*
593 	 * elements is a variable-length array of ACPI objects, one for
594 	 * each property of the WMI object instance, except that the
595 	 * strings in PossibleStates[] are flattened into this array
596 	 * as if each individual string were a property by itself.
597 	 */
598 	elements = wobj->package.elements;
599 
600 	elem_count = wobj->package.count;
601 	if (elem_count <= HP_WMI_PROPERTY_SIZE ||
602 	    elem_count > HP_WMI_MAX_PROPERTIES)
603 		return -EINVAL;
604 
605 	type = elements[HP_WMI_PROPERTY_SIZE].type;
606 	switch (type) {
607 	case ACPI_TYPE_INTEGER:
608 		is_new = true;
609 		last_prop = HP_WMI_PROPERTY_RATE_UNITS;
610 		break;
611 
612 	case ACPI_TYPE_STRING:
613 		is_new = false;
614 		last_prop = HP_WMI_PROPERTY_CURRENT_READING;
615 		break;
616 
617 	default:
618 		return -EINVAL;
619 	}
620 
621 	/*
622 	 * In general, the count of PossibleStates[] must be > 0.
623 	 * Also, the old variant lacks the Size property, so we may need to
624 	 * reduce the value of last_prop by 1 when doing arithmetic with it.
625 	 */
626 	if (elem_count < last_prop - !is_new + 1)
627 		return -EINVAL;
628 
629 	count = elem_count - (last_prop - !is_new);
630 
631 	for (i = 0; i < elem_count && prop <= last_prop; i++, prop++) {
632 		type = elements[i].type;
633 		valid_type = hp_wmi_property_map[prop];
634 		if (type != valid_type)
635 			return -EINVAL;
636 
637 		switch (prop) {
638 		case HP_WMI_PROPERTY_OPERATIONAL_STATUS:
639 			/* Old variant: CurrentState follows OperationalStatus. */
640 			if (!is_new)
641 				prop = HP_WMI_PROPERTY_CURRENT_STATE - 1;
642 			break;
643 
644 		case HP_WMI_PROPERTY_SIZE:
645 			/* New variant: Size == count of PossibleStates[]. */
646 			if (count != elements[i].integer.value)
647 				return -EINVAL;
648 			break;
649 
650 		case HP_WMI_PROPERTY_POSSIBLE_STATES:
651 			/* PossibleStates[0] has already been type-checked. */
652 			for (j = 0; i + 1 < elem_count && j + 1 < count; j++) {
653 				type = elements[++i].type;
654 				if (type != valid_type)
655 					return -EINVAL;
656 			}
657 
658 			/* Old variant: BaseUnits follows PossibleStates[]. */
659 			if (!is_new)
660 				prop = HP_WMI_PROPERTY_BASE_UNITS - 1;
661 			break;
662 
663 		case HP_WMI_PROPERTY_CURRENT_STATE:
664 			/* Old variant: PossibleStates[] follows CurrentState. */
665 			if (!is_new)
666 				prop = HP_WMI_PROPERTY_POSSIBLE_STATES - 1;
667 			break;
668 		}
669 	}
670 
671 	if (prop != last_prop + 1)
672 		return -EINVAL;
673 
674 	*out_size = count;
675 	*out_is_new = is_new;
676 
677 	return 0;
678 }
679 
680 static int
681 numeric_sensor_is_connected(const struct hp_wmi_numeric_sensor *nsensor)
682 {
683 	u32 operational_status = nsensor->operational_status;
684 
685 	return operational_status != HP_WMI_STATUS_NO_CONTACT;
686 }
687 
688 static int numeric_sensor_has_fault(const struct hp_wmi_numeric_sensor *nsensor)
689 {
690 	u32 operational_status = nsensor->operational_status;
691 
692 	switch (operational_status) {
693 	case HP_WMI_STATUS_DEGRADED:
694 	case HP_WMI_STATUS_STRESSED:		/* e.g. Overload, overtemp. */
695 	case HP_WMI_STATUS_PREDICTIVE_FAILURE:	/* e.g. Fan removed. */
696 	case HP_WMI_STATUS_ERROR:
697 	case HP_WMI_STATUS_NON_RECOVERABLE_ERROR:
698 	case HP_WMI_STATUS_NO_CONTACT:
699 	case HP_WMI_STATUS_LOST_COMMUNICATION:
700 	case HP_WMI_STATUS_ABORTED:
701 	case HP_WMI_STATUS_SUPPORTING_ENTITY_IN_ERROR:
702 
703 	/* Assume combination by addition; bitwise OR doesn't make sense. */
704 	case HP_WMI_STATUS_COMPLETED + HP_WMI_STATUS_DEGRADED:
705 	case HP_WMI_STATUS_COMPLETED + HP_WMI_STATUS_ERROR:
706 		return true;
707 	}
708 
709 	return false;
710 }
711 
712 /* scale_numeric_sensor - scale sensor reading for hwmon */
713 static long scale_numeric_sensor(const struct hp_wmi_numeric_sensor *nsensor)
714 {
715 	u32 current_reading = nsensor->current_reading;
716 	s32 unit_modifier = nsensor->unit_modifier;
717 	u32 sensor_type = nsensor->sensor_type;
718 	u32 base_units = nsensor->base_units;
719 	s32 target_modifier;
720 	long val;
721 
722 	/* Fan readings are in RPM units; others are in milliunits. */
723 	target_modifier = sensor_type == HP_WMI_TYPE_AIR_FLOW ? 0 : -3;
724 
725 	val = current_reading;
726 
727 	for (; unit_modifier < target_modifier; unit_modifier++)
728 		val = DIV_ROUND_CLOSEST(val, 10);
729 
730 	for (; unit_modifier > target_modifier; unit_modifier--) {
731 		if (val > LONG_MAX / 10) {
732 			val = LONG_MAX;
733 			break;
734 		}
735 		val *= 10;
736 	}
737 
738 	if (sensor_type == HP_WMI_TYPE_TEMPERATURE) {
739 		switch (base_units) {
740 		case HP_WMI_UNITS_DEGREES_F:
741 			val -= MILLI * 32;
742 			val = val <= LONG_MAX / 5 ?
743 				      DIV_ROUND_CLOSEST(val * 5, 9) :
744 				      DIV_ROUND_CLOSEST(val, 9) * 5;
745 			break;
746 
747 		case HP_WMI_UNITS_DEGREES_K:
748 			val = milli_kelvin_to_millicelsius(val);
749 			break;
750 		}
751 	}
752 
753 	return val;
754 }
755 
756 /*
757  * classify_numeric_sensor - classify a numeric sensor
758  * @nsensor: pointer to numeric sensor struct
759  *
760  * Returns an enum hp_wmi_type value on success,
761  * or a negative value if the sensor type is unsupported.
762  */
763 static int classify_numeric_sensor(const struct hp_wmi_numeric_sensor *nsensor)
764 {
765 	u32 sensor_type = nsensor->sensor_type;
766 	u32 base_units = nsensor->base_units;
767 	const char *name = nsensor->name;
768 
769 	switch (sensor_type) {
770 	case HP_WMI_TYPE_TEMPERATURE:
771 		/*
772 		 * Some systems have sensors named "X Thermal Index" in "Other"
773 		 * units. Tested CPU sensor examples were found to be in °C,
774 		 * albeit perhaps "differently" accurate; e.g. readings were
775 		 * reliably -6°C vs. coretemp on a HP Compaq Elite 8300, and
776 		 * +8°C on an EliteOne G1 800. But this is still within the
777 		 * realm of plausibility for cheaply implemented motherboard
778 		 * sensors, and chassis readings were about as expected.
779 		 */
780 		if ((base_units == HP_WMI_UNITS_OTHER &&
781 		     strstr(name, HP_WMI_PATTERN_TEMP_SENSOR)) ||
782 		    base_units == HP_WMI_UNITS_DEGREES_C ||
783 		    base_units == HP_WMI_UNITS_DEGREES_F ||
784 		    base_units == HP_WMI_UNITS_DEGREES_K)
785 			return HP_WMI_TYPE_TEMPERATURE;
786 		break;
787 
788 	case HP_WMI_TYPE_VOLTAGE:
789 		if (base_units == HP_WMI_UNITS_VOLTS)
790 			return HP_WMI_TYPE_VOLTAGE;
791 		break;
792 
793 	case HP_WMI_TYPE_CURRENT:
794 		if (base_units == HP_WMI_UNITS_AMPS)
795 			return HP_WMI_TYPE_CURRENT;
796 		break;
797 
798 	case HP_WMI_TYPE_AIR_FLOW:
799 		/*
800 		 * Strangely, HP considers fan RPM sensor type to be
801 		 * "Air Flow" instead of the more intuitive "Tachometer".
802 		 */
803 		if (base_units == HP_WMI_UNITS_RPM)
804 			return HP_WMI_TYPE_AIR_FLOW;
805 		break;
806 	}
807 
808 	return -EINVAL;
809 }
810 
811 static int
812 populate_numeric_sensor_from_wobj(struct device *dev,
813 				  struct hp_wmi_numeric_sensor *nsensor,
814 				  union acpi_object *wobj, bool *out_is_new)
815 {
816 	int last_prop = HP_WMI_PROPERTY_RATE_UNITS;
817 	int prop = HP_WMI_PROPERTY_NAME;
818 	const char **possible_states;
819 	union acpi_object *element;
820 	acpi_object_type type;
821 	char *string;
822 	bool is_new;
823 	u32 value;
824 	u8 size;
825 	int err;
826 
827 	err = check_numeric_sensor_wobj(wobj, &size, &is_new);
828 	if (err)
829 		return err;
830 
831 	possible_states = devm_kcalloc(dev, size, sizeof(*possible_states),
832 				       GFP_KERNEL);
833 	if (!possible_states)
834 		return -ENOMEM;
835 
836 	element = wobj->package.elements;
837 	nsensor->possible_states = possible_states;
838 	nsensor->size = size;
839 
840 	if (!is_new)
841 		last_prop = HP_WMI_PROPERTY_CURRENT_READING;
842 
843 	for (; prop <= last_prop; prop++) {
844 		type = hp_wmi_property_map[prop];
845 
846 		err = extract_acpi_value(dev, element, type, &value, &string);
847 		if (err)
848 			return err;
849 
850 		element++;
851 
852 		switch (prop) {
853 		case HP_WMI_PROPERTY_NAME:
854 			nsensor->name = string;
855 			break;
856 
857 		case HP_WMI_PROPERTY_DESCRIPTION:
858 			nsensor->description = string;
859 			break;
860 
861 		case HP_WMI_PROPERTY_SENSOR_TYPE:
862 			if (value > HP_WMI_TYPE_AIR_FLOW)
863 				return -EINVAL;
864 
865 			nsensor->sensor_type = value;
866 			break;
867 
868 		case HP_WMI_PROPERTY_OTHER_SENSOR_TYPE:
869 			nsensor->other_sensor_type = string;
870 			break;
871 
872 		case HP_WMI_PROPERTY_OPERATIONAL_STATUS:
873 			nsensor->operational_status = value;
874 
875 			/* Old variant: CurrentState follows OperationalStatus. */
876 			if (!is_new)
877 				prop = HP_WMI_PROPERTY_CURRENT_STATE - 1;
878 			break;
879 
880 		case HP_WMI_PROPERTY_SIZE:
881 			break;			/* Already set. */
882 
883 		case HP_WMI_PROPERTY_POSSIBLE_STATES:
884 			*possible_states++ = string;
885 			if (--size)
886 				prop--;
887 
888 			/* Old variant: BaseUnits follows PossibleStates[]. */
889 			if (!is_new && !size)
890 				prop = HP_WMI_PROPERTY_BASE_UNITS - 1;
891 			break;
892 
893 		case HP_WMI_PROPERTY_CURRENT_STATE:
894 			nsensor->current_state = string;
895 
896 			/* Old variant: PossibleStates[] follows CurrentState. */
897 			if (!is_new)
898 				prop = HP_WMI_PROPERTY_POSSIBLE_STATES - 1;
899 			break;
900 
901 		case HP_WMI_PROPERTY_BASE_UNITS:
902 			nsensor->base_units = value;
903 			break;
904 
905 		case HP_WMI_PROPERTY_UNIT_MODIFIER:
906 			/* UnitModifier is signed. */
907 			nsensor->unit_modifier = (s32)value;
908 			break;
909 
910 		case HP_WMI_PROPERTY_CURRENT_READING:
911 			nsensor->current_reading = value;
912 			break;
913 
914 		case HP_WMI_PROPERTY_RATE_UNITS:
915 			nsensor->rate_units = value;
916 			break;
917 
918 		default:
919 			return -EINVAL;
920 		}
921 	}
922 
923 	*out_is_new = is_new;
924 
925 	return 0;
926 }
927 
928 /* update_numeric_sensor_from_wobj - update fungible sensor properties */
929 static void
930 update_numeric_sensor_from_wobj(struct device *dev,
931 				struct hp_wmi_numeric_sensor *nsensor,
932 				const union acpi_object *wobj)
933 {
934 	const union acpi_object *elements;
935 	const union acpi_object *element;
936 	const char *new_string;
937 	char *trimmed;
938 	char *string;
939 	bool is_new;
940 	int offset;
941 	u8 size;
942 	int err;
943 
944 	err = check_numeric_sensor_wobj(wobj, &size, &is_new);
945 	if (err)
946 		return;
947 
948 	elements = wobj->package.elements;
949 
950 	element = &elements[HP_WMI_PROPERTY_OPERATIONAL_STATUS];
951 	nsensor->operational_status = element->integer.value;
952 
953 	/*
954 	 * In general, an index offset is needed after PossibleStates[0].
955 	 * On a new variant, CurrentState is after PossibleStates[]. This is
956 	 * not the case on an old variant, but we still need to offset the
957 	 * read because CurrentState is where Size would be on a new variant.
958 	 */
959 	offset = is_new ? size - 1 : -2;
960 
961 	element = &elements[HP_WMI_PROPERTY_CURRENT_STATE + offset];
962 	string = element->type == ACPI_TYPE_BUFFER ?
963 		convert_raw_wmi_string(element->buffer.pointer) :
964 		element->string.pointer;
965 
966 	if (string) {
967 		trimmed = strim(string);
968 		if (strcmp(trimmed, nsensor->current_state)) {
969 			new_string = hp_wmi_strdup(dev, trimmed);
970 			if (new_string) {
971 				devm_kfree(dev, nsensor->current_state);
972 				nsensor->current_state = new_string;
973 			}
974 		}
975 		if (element->type == ACPI_TYPE_BUFFER)
976 			kfree(string);
977 	}
978 
979 	/* Old variant: -2 (not -1) because it lacks the Size property. */
980 	if (!is_new)
981 		offset = (int)size - 2;	/* size is > 0, i.e. may be 1. */
982 
983 	element = &elements[HP_WMI_PROPERTY_UNIT_MODIFIER + offset];
984 	nsensor->unit_modifier = (s32)element->integer.value;
985 
986 	element = &elements[HP_WMI_PROPERTY_CURRENT_READING + offset];
987 	nsensor->current_reading = element->integer.value;
988 }
989 
990 /*
991  * check_platform_events_wobj - validate a HPBIOS_PlatformEvents instance
992  * @wobj: pointer to WMI object instance to check
993  *
994  * Returns 0 on success, or a negative error code on error.
995  */
996 static int check_platform_events_wobj(const union acpi_object *wobj)
997 {
998 	return check_wobj(wobj, hp_wmi_platform_events_property_map,
999 			  HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_STATUS);
1000 }
1001 
1002 static int
1003 populate_platform_events_from_wobj(struct device *dev,
1004 				   struct hp_wmi_platform_events *pevents,
1005 				   union acpi_object *wobj)
1006 {
1007 	int last_prop = HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_STATUS;
1008 	int prop = HP_WMI_PLATFORM_EVENTS_PROPERTY_NAME;
1009 	union acpi_object *element;
1010 	acpi_object_type type;
1011 	char *string;
1012 	u32 value;
1013 	int err;
1014 
1015 	err = check_platform_events_wobj(wobj);
1016 	if (err)
1017 		return err;
1018 
1019 	element = wobj->package.elements;
1020 
1021 	for (; prop <= last_prop; prop++, element++) {
1022 		type = hp_wmi_platform_events_property_map[prop];
1023 
1024 		err = extract_acpi_value(dev, element, type, &value, &string);
1025 		if (err)
1026 			return err;
1027 
1028 		switch (prop) {
1029 		case HP_WMI_PLATFORM_EVENTS_PROPERTY_NAME:
1030 			pevents->name = string;
1031 			break;
1032 
1033 		case HP_WMI_PLATFORM_EVENTS_PROPERTY_DESCRIPTION:
1034 			pevents->description = string;
1035 			break;
1036 
1037 		case HP_WMI_PLATFORM_EVENTS_PROPERTY_SOURCE_NAMESPACE:
1038 			if (strcasecmp(HP_WMI_EVENT_NAMESPACE, string))
1039 				return -EINVAL;
1040 
1041 			pevents->source_namespace = string;
1042 			break;
1043 
1044 		case HP_WMI_PLATFORM_EVENTS_PROPERTY_SOURCE_CLASS:
1045 			if (strcasecmp(HP_WMI_EVENT_CLASS, string))
1046 				return -EINVAL;
1047 
1048 			pevents->source_class = string;
1049 			break;
1050 
1051 		case HP_WMI_PLATFORM_EVENTS_PROPERTY_CATEGORY:
1052 			pevents->category = value;
1053 			break;
1054 
1055 		case HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_SEVERITY:
1056 			pevents->possible_severity = value;
1057 			break;
1058 
1059 		case HP_WMI_PLATFORM_EVENTS_PROPERTY_POSSIBLE_STATUS:
1060 			pevents->possible_status = value;
1061 			break;
1062 
1063 		default:
1064 			return -EINVAL;
1065 		}
1066 	}
1067 
1068 	return 0;
1069 }
1070 
1071 /*
1072  * check_event_wobj - validate a HPBIOS_BIOSEvent instance
1073  * @wobj: pointer to WMI object instance to check
1074  *
1075  * Returns 0 on success, or a negative error code on error.
1076  */
1077 static int check_event_wobj(const union acpi_object *wobj)
1078 {
1079 	return check_wobj(wobj, hp_wmi_event_property_map,
1080 			  HP_WMI_EVENT_PROPERTY_STATUS);
1081 }
1082 
1083 static int populate_event_from_wobj(struct device *dev,
1084 				    struct hp_wmi_event *event,
1085 				    union acpi_object *wobj)
1086 {
1087 	int prop = HP_WMI_EVENT_PROPERTY_NAME;
1088 	union acpi_object *element;
1089 	acpi_object_type type;
1090 	char *string;
1091 	u32 value;
1092 	int err;
1093 
1094 	err = check_event_wobj(wobj);
1095 	if (err)
1096 		return err;
1097 
1098 	element = wobj->package.elements;
1099 
1100 	for (; prop <= HP_WMI_EVENT_PROPERTY_CATEGORY; prop++, element++) {
1101 		type = hp_wmi_event_property_map[prop];
1102 
1103 		err = extract_acpi_value(dev, element, type, &value, &string);
1104 		if (err)
1105 			return err;
1106 
1107 		switch (prop) {
1108 		case HP_WMI_EVENT_PROPERTY_NAME:
1109 			event->name = string;
1110 			break;
1111 
1112 		case HP_WMI_EVENT_PROPERTY_DESCRIPTION:
1113 			event->description = string;
1114 			break;
1115 
1116 		case HP_WMI_EVENT_PROPERTY_CATEGORY:
1117 			event->category = value;
1118 			break;
1119 
1120 		default:
1121 			return -EINVAL;
1122 		}
1123 	}
1124 
1125 	return 0;
1126 }
1127 
1128 /*
1129  * classify_event - classify an event
1130  * @name: event name
1131  * @category: event category
1132  *
1133  * Classify instances of both HPBIOS_PlatformEvents and HPBIOS_BIOSEvent from
1134  * property values. Recognition criteria are based on multiple ACPI dumps [3].
1135  *
1136  * Returns an enum hp_wmi_type value on success,
1137  * or a negative value if the event type is unsupported.
1138  */
1139 static int classify_event(const char *event_name, u32 category)
1140 {
1141 	if (category != HP_WMI_CATEGORY_SENSOR)
1142 		return -EINVAL;
1143 
1144 	/* Fan events have Name "X Stall". */
1145 	if (strstr(event_name, HP_WMI_PATTERN_FAN_ALARM))
1146 		return HP_WMI_TYPE_AIR_FLOW;
1147 
1148 	/* Intrusion events have Name "Hood Intrusion". */
1149 	if (!strcmp(event_name, HP_WMI_PATTERN_INTRUSION_ALARM))
1150 		return HP_WMI_TYPE_INTRUSION;
1151 
1152 	/*
1153 	 * Temperature events have Name either "Thermal Caution" or
1154 	 * "Thermal Critical". Deal only with "Thermal Critical" events.
1155 	 *
1156 	 * "Thermal Caution" events have Status "Stressed", informing us that
1157 	 * the OperationalStatus of the related sensor has become "Stressed".
1158 	 * However, this is already a fault condition that will clear itself
1159 	 * when the sensor recovers, so we have no further interest in them.
1160 	 */
1161 	if (!strcmp(event_name, HP_WMI_PATTERN_TEMP_ALARM))
1162 		return HP_WMI_TYPE_TEMPERATURE;
1163 
1164 	return -EINVAL;
1165 }
1166 
1167 /*
1168  * interpret_info - interpret sensor for hwmon
1169  * @info: pointer to sensor info struct
1170  *
1171  * Should be called after the numeric sensor member has been updated.
1172  */
1173 static void interpret_info(struct hp_wmi_info *info)
1174 {
1175 	const struct hp_wmi_numeric_sensor *nsensor = &info->nsensor;
1176 
1177 	info->cached_val = scale_numeric_sensor(nsensor);
1178 	info->last_updated = jiffies;
1179 }
1180 
1181 /*
1182  * hp_wmi_update_info - poll WMI to update sensor info
1183  * @state: pointer to driver state
1184  * @info: pointer to sensor info struct
1185  *
1186  * Returns 0 on success, or a negative error code on error.
1187  */
1188 static int hp_wmi_update_info(struct hp_wmi_sensors *state,
1189 			      struct hp_wmi_info *info)
1190 {
1191 	struct hp_wmi_numeric_sensor *nsensor = &info->nsensor;
1192 	struct device *dev = &state->wdev->dev;
1193 	const union acpi_object *wobj;
1194 	u8 instance = info->instance;
1195 	int ret = 0;
1196 
1197 	if (time_after(jiffies, info->last_updated + HZ)) {
1198 		mutex_lock(&state->lock);
1199 
1200 		wobj = hp_wmi_get_wobj(HP_WMI_NUMERIC_SENSOR_GUID, instance);
1201 		if (!wobj) {
1202 			ret = -EIO;
1203 			goto out_unlock;
1204 		}
1205 
1206 		update_numeric_sensor_from_wobj(dev, nsensor, wobj);
1207 
1208 		interpret_info(info);
1209 
1210 		kfree(wobj);
1211 
1212 out_unlock:
1213 		mutex_unlock(&state->lock);
1214 	}
1215 
1216 	return ret;
1217 }
1218 
1219 static int basic_string_show(struct seq_file *seqf, void *ignored)
1220 {
1221 	const char *str = seqf->private;
1222 
1223 	seq_printf(seqf, "%s\n", str);
1224 
1225 	return 0;
1226 }
1227 DEFINE_SHOW_ATTRIBUTE(basic_string);
1228 
1229 static int fungible_show(struct seq_file *seqf, enum hp_wmi_property prop)
1230 {
1231 	struct hp_wmi_numeric_sensor *nsensor;
1232 	struct hp_wmi_sensors *state;
1233 	struct hp_wmi_info *info;
1234 	int err;
1235 
1236 	info = seqf->private;
1237 	state = info->state;
1238 	nsensor = &info->nsensor;
1239 
1240 	err = hp_wmi_update_info(state, info);
1241 	if (err)
1242 		return err;
1243 
1244 	switch (prop) {
1245 	case HP_WMI_PROPERTY_OPERATIONAL_STATUS:
1246 		seq_printf(seqf, "%u\n", nsensor->operational_status);
1247 		break;
1248 
1249 	case HP_WMI_PROPERTY_CURRENT_STATE:
1250 		seq_printf(seqf, "%s\n", nsensor->current_state);
1251 		break;
1252 
1253 	case HP_WMI_PROPERTY_UNIT_MODIFIER:
1254 		seq_printf(seqf, "%d\n", nsensor->unit_modifier);
1255 		break;
1256 
1257 	case HP_WMI_PROPERTY_CURRENT_READING:
1258 		seq_printf(seqf, "%u\n", nsensor->current_reading);
1259 		break;
1260 
1261 	default:
1262 		return -EOPNOTSUPP;
1263 	}
1264 
1265 	return 0;
1266 }
1267 
1268 static int operational_status_show(struct seq_file *seqf, void *ignored)
1269 {
1270 	return fungible_show(seqf, HP_WMI_PROPERTY_OPERATIONAL_STATUS);
1271 }
1272 DEFINE_SHOW_ATTRIBUTE(operational_status);
1273 
1274 static int current_state_show(struct seq_file *seqf, void *ignored)
1275 {
1276 	return fungible_show(seqf, HP_WMI_PROPERTY_CURRENT_STATE);
1277 }
1278 DEFINE_SHOW_ATTRIBUTE(current_state);
1279 
1280 static int possible_states_show(struct seq_file *seqf, void *ignored)
1281 {
1282 	struct hp_wmi_numeric_sensor *nsensor = seqf->private;
1283 	u8 i;
1284 
1285 	for (i = 0; i < nsensor->size; i++)
1286 		seq_printf(seqf, "%s%s", i ? "," : "",
1287 			   nsensor->possible_states[i]);
1288 
1289 	seq_puts(seqf, "\n");
1290 
1291 	return 0;
1292 }
1293 DEFINE_SHOW_ATTRIBUTE(possible_states);
1294 
1295 static int unit_modifier_show(struct seq_file *seqf, void *ignored)
1296 {
1297 	return fungible_show(seqf, HP_WMI_PROPERTY_UNIT_MODIFIER);
1298 }
1299 DEFINE_SHOW_ATTRIBUTE(unit_modifier);
1300 
1301 static int current_reading_show(struct seq_file *seqf, void *ignored)
1302 {
1303 	return fungible_show(seqf, HP_WMI_PROPERTY_CURRENT_READING);
1304 }
1305 DEFINE_SHOW_ATTRIBUTE(current_reading);
1306 
1307 /* hp_wmi_devm_debugfs_remove - devm callback for debugfs cleanup */
1308 static void hp_wmi_devm_debugfs_remove(void *res)
1309 {
1310 	debugfs_remove_recursive(res);
1311 }
1312 
1313 /* hp_wmi_debugfs_init - create and populate debugfs directory tree */
1314 static void hp_wmi_debugfs_init(struct device *dev, struct hp_wmi_info *info,
1315 				struct hp_wmi_platform_events *pevents,
1316 				u8 icount, u8 pcount, bool is_new)
1317 {
1318 	struct hp_wmi_numeric_sensor *nsensor;
1319 	char buf[HP_WMI_MAX_STR_SIZE];
1320 	struct dentry *debugfs;
1321 	struct dentry *entries;
1322 	struct dentry *dir;
1323 	int err;
1324 	u8 i;
1325 
1326 	/* dev_name() gives a not-very-friendly GUID for WMI devices. */
1327 	scnprintf(buf, sizeof(buf), "hp-wmi-sensors-%u", dev->id);
1328 
1329 	debugfs = debugfs_create_dir(buf, NULL);
1330 	if (IS_ERR(debugfs))
1331 		return;
1332 
1333 	err = devm_add_action_or_reset(dev, hp_wmi_devm_debugfs_remove,
1334 				       debugfs);
1335 	if (err)
1336 		return;
1337 
1338 	entries = debugfs_create_dir("sensor", debugfs);
1339 
1340 	for (i = 0; i < icount; i++, info++) {
1341 		nsensor = &info->nsensor;
1342 
1343 		scnprintf(buf, sizeof(buf), "%u", i);
1344 		dir = debugfs_create_dir(buf, entries);
1345 
1346 		debugfs_create_file("name", 0444, dir,
1347 				    (void *)nsensor->name,
1348 				    &basic_string_fops);
1349 
1350 		debugfs_create_file("description", 0444, dir,
1351 				    (void *)nsensor->description,
1352 				    &basic_string_fops);
1353 
1354 		debugfs_create_u32("sensor_type", 0444, dir,
1355 				   &nsensor->sensor_type);
1356 
1357 		debugfs_create_file("other_sensor_type", 0444, dir,
1358 				    (void *)nsensor->other_sensor_type,
1359 				    &basic_string_fops);
1360 
1361 		debugfs_create_file("operational_status", 0444, dir,
1362 				    info, &operational_status_fops);
1363 
1364 		debugfs_create_file("possible_states", 0444, dir,
1365 				    nsensor, &possible_states_fops);
1366 
1367 		debugfs_create_file("current_state", 0444, dir,
1368 				    info, &current_state_fops);
1369 
1370 		debugfs_create_u32("base_units", 0444, dir,
1371 				   &nsensor->base_units);
1372 
1373 		debugfs_create_file("unit_modifier", 0444, dir,
1374 				    info, &unit_modifier_fops);
1375 
1376 		debugfs_create_file("current_reading", 0444, dir,
1377 				    info, &current_reading_fops);
1378 
1379 		if (is_new)
1380 			debugfs_create_u32("rate_units", 0444, dir,
1381 					   &nsensor->rate_units);
1382 	}
1383 
1384 	if (!pcount)
1385 		return;
1386 
1387 	entries = debugfs_create_dir("platform_events", debugfs);
1388 
1389 	for (i = 0; i < pcount; i++, pevents++) {
1390 		scnprintf(buf, sizeof(buf), "%u", i);
1391 		dir = debugfs_create_dir(buf, entries);
1392 
1393 		debugfs_create_file("name", 0444, dir,
1394 				    (void *)pevents->name,
1395 				    &basic_string_fops);
1396 
1397 		debugfs_create_file("description", 0444, dir,
1398 				    (void *)pevents->description,
1399 				    &basic_string_fops);
1400 
1401 		debugfs_create_file("source_namespace", 0444, dir,
1402 				    (void *)pevents->source_namespace,
1403 				    &basic_string_fops);
1404 
1405 		debugfs_create_file("source_class", 0444, dir,
1406 				    (void *)pevents->source_class,
1407 				    &basic_string_fops);
1408 
1409 		debugfs_create_u32("category", 0444, dir,
1410 				   &pevents->category);
1411 
1412 		debugfs_create_u32("possible_severity", 0444, dir,
1413 				   &pevents->possible_severity);
1414 
1415 		debugfs_create_u32("possible_status", 0444, dir,
1416 				   &pevents->possible_status);
1417 	}
1418 }
1419 
1420 static umode_t hp_wmi_hwmon_is_visible(const void *drvdata,
1421 				       enum hwmon_sensor_types type,
1422 				       u32 attr, int channel)
1423 {
1424 	const struct hp_wmi_sensors *state = drvdata;
1425 	const struct hp_wmi_info *info;
1426 
1427 	if (type == hwmon_intrusion)
1428 		return state->has_intrusion ? 0644 : 0;
1429 
1430 	if (!state->info_map[type] || !state->info_map[type][channel])
1431 		return 0;
1432 
1433 	info = state->info_map[type][channel];
1434 
1435 	if ((type == hwmon_temp && attr == hwmon_temp_alarm) ||
1436 	    (type == hwmon_fan  && attr == hwmon_fan_alarm))
1437 		return info->has_alarm ? 0444 : 0;
1438 
1439 	return 0444;
1440 }
1441 
1442 static int hp_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
1443 			     u32 attr, int channel, long *out_val)
1444 {
1445 	struct hp_wmi_sensors *state = dev_get_drvdata(dev);
1446 	const struct hp_wmi_numeric_sensor *nsensor;
1447 	struct hp_wmi_info *info;
1448 	int err;
1449 
1450 	if (type == hwmon_intrusion) {
1451 		*out_val = state->intrusion ? 1 : 0;
1452 
1453 		return 0;
1454 	}
1455 
1456 	info = state->info_map[type][channel];
1457 
1458 	if ((type == hwmon_temp && attr == hwmon_temp_alarm) ||
1459 	    (type == hwmon_fan  && attr == hwmon_fan_alarm)) {
1460 		*out_val = info->alarm ? 1 : 0;
1461 		info->alarm = false;
1462 
1463 		return 0;
1464 	}
1465 
1466 	nsensor = &info->nsensor;
1467 
1468 	err = hp_wmi_update_info(state, info);
1469 	if (err)
1470 		return err;
1471 
1472 	if ((type == hwmon_temp && attr == hwmon_temp_fault) ||
1473 	    (type == hwmon_fan  && attr == hwmon_fan_fault))
1474 		*out_val = numeric_sensor_has_fault(nsensor);
1475 	else
1476 		*out_val = info->cached_val;
1477 
1478 	return 0;
1479 }
1480 
1481 static int hp_wmi_hwmon_read_string(struct device *dev,
1482 				    enum hwmon_sensor_types type, u32 attr,
1483 				    int channel, const char **out_str)
1484 {
1485 	const struct hp_wmi_sensors *state = dev_get_drvdata(dev);
1486 	const struct hp_wmi_info *info;
1487 
1488 	info = state->info_map[type][channel];
1489 	*out_str = info->nsensor.name;
1490 
1491 	return 0;
1492 }
1493 
1494 static int hp_wmi_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
1495 			      u32 attr, int channel, long val)
1496 {
1497 	struct hp_wmi_sensors *state = dev_get_drvdata(dev);
1498 
1499 	if (val)
1500 		return -EINVAL;
1501 
1502 	mutex_lock(&state->lock);
1503 
1504 	state->intrusion = false;
1505 
1506 	mutex_unlock(&state->lock);
1507 
1508 	return 0;
1509 }
1510 
1511 static const struct hwmon_ops hp_wmi_hwmon_ops = {
1512 	.is_visible  = hp_wmi_hwmon_is_visible,
1513 	.read	     = hp_wmi_hwmon_read,
1514 	.read_string = hp_wmi_hwmon_read_string,
1515 	.write	     = hp_wmi_hwmon_write,
1516 };
1517 
1518 static struct hwmon_chip_info hp_wmi_chip_info = {
1519 	.ops         = &hp_wmi_hwmon_ops,
1520 	.info        = NULL,
1521 };
1522 
1523 static struct hp_wmi_info *match_fan_event(struct hp_wmi_sensors *state,
1524 					   const char *event_description)
1525 {
1526 	struct hp_wmi_info **ptr_info = state->info_map[hwmon_fan];
1527 	u8 fan_count = state->channel_count[hwmon_fan];
1528 	struct hp_wmi_info *info;
1529 	const char *name;
1530 	u8 i;
1531 
1532 	/* Fan event has Description "X Speed". Sensor has Name "X[ Speed]". */
1533 
1534 	for (i = 0; i < fan_count; i++, ptr_info++) {
1535 		info = *ptr_info;
1536 		name = info->nsensor.name;
1537 
1538 		if (strstr(event_description, name))
1539 			return info;
1540 	}
1541 
1542 	return NULL;
1543 }
1544 
1545 static u8 match_temp_events(struct hp_wmi_sensors *state,
1546 			    const char *event_description,
1547 			    struct hp_wmi_info *temp_info[])
1548 {
1549 	struct hp_wmi_info **ptr_info = state->info_map[hwmon_temp];
1550 	u8 temp_count = state->channel_count[hwmon_temp];
1551 	struct hp_wmi_info *info;
1552 	const char *name;
1553 	u8 count = 0;
1554 	bool is_cpu;
1555 	bool is_sys;
1556 	u8 i;
1557 
1558 	/* Description is either "CPU Thermal Index" or "Chassis Thermal Index". */
1559 
1560 	is_cpu = !strcmp(event_description, HP_WMI_PATTERN_CPU_TEMP);
1561 	is_sys = !strcmp(event_description, HP_WMI_PATTERN_SYS_TEMP);
1562 	if (!is_cpu && !is_sys)
1563 		return 0;
1564 
1565 	/*
1566 	 * CPU event: Match one sensor with Name either "CPU Thermal Index" or
1567 	 * "CPU Temperature", or multiple with Name(s) "CPU[#] Temperature".
1568 	 *
1569 	 * Chassis event: Match one sensor with Name either
1570 	 * "Chassis Thermal Index" or "System Ambient Temperature".
1571 	 */
1572 
1573 	for (i = 0; i < temp_count; i++, ptr_info++) {
1574 		info = *ptr_info;
1575 		name = info->nsensor.name;
1576 
1577 		if ((is_cpu && (!strcmp(name, HP_WMI_PATTERN_CPU_TEMP) ||
1578 				!strcmp(name, HP_WMI_PATTERN_CPU_TEMP2))) ||
1579 		    (is_sys && (!strcmp(name, HP_WMI_PATTERN_SYS_TEMP) ||
1580 				!strcmp(name, HP_WMI_PATTERN_SYS_TEMP2)))) {
1581 			temp_info[0] = info;
1582 			return 1;
1583 		}
1584 
1585 		if (is_cpu && (strstr(name, HP_WMI_PATTERN_CPU) &&
1586 			       strstr(name, HP_WMI_PATTERN_TEMP)))
1587 			temp_info[count++] = info;
1588 	}
1589 
1590 	return count;
1591 }
1592 
1593 /* hp_wmi_devm_debugfs_remove - devm callback for WMI event handler removal */
1594 static void hp_wmi_devm_notify_remove(void *ignored)
1595 {
1596 	wmi_remove_notify_handler(HP_WMI_EVENT_GUID);
1597 }
1598 
1599 /* hp_wmi_notify - WMI event notification handler */
1600 static void hp_wmi_notify(u32 value, void *context)
1601 {
1602 	struct hp_wmi_info *temp_info[HP_WMI_MAX_INSTANCES] = {};
1603 	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
1604 	struct hp_wmi_sensors *state = context;
1605 	struct device *dev = &state->wdev->dev;
1606 	struct hp_wmi_event event = {};
1607 	struct hp_wmi_info *fan_info;
1608 	union acpi_object *wobj;
1609 	acpi_status err;
1610 	int event_type;
1611 	u8 count;
1612 
1613 	/*
1614 	 * The following warning may occur in the kernel log:
1615 	 *
1616 	 *   ACPI Warning: \_SB.WMID._WED: Return type mismatch -
1617 	 *     found Package, expected Integer/String/Buffer
1618 	 *
1619 	 * After using [4] to decode BMOF blobs found in [3], careless copying
1620 	 * of BIOS code seems the most likely explanation for this warning.
1621 	 * HP_WMI_EVENT_GUID refers to \\.\root\WMI\HPBIOS_BIOSEvent on
1622 	 * business-class systems, but it refers to \\.\root\WMI\hpqBEvnt on
1623 	 * non-business-class systems. Per the existing hp-wmi driver, it
1624 	 * looks like an instance of hpqBEvnt delivered as event data may
1625 	 * indeed take the form of a raw ACPI_BUFFER on non-business-class
1626 	 * systems ("may" because ASL shows some BIOSes do strange things).
1627 	 *
1628 	 * In any case, we can ignore this warning, because we always validate
1629 	 * the event data to ensure it is an ACPI_PACKAGE containing a
1630 	 * HPBIOS_BIOSEvent instance.
1631 	 */
1632 
1633 	mutex_lock(&state->lock);
1634 
1635 	err = wmi_get_event_data(value, &out);
1636 	if (ACPI_FAILURE(err))
1637 		goto out_unlock;
1638 
1639 	wobj = out.pointer;
1640 	if (!wobj)
1641 		goto out_unlock;
1642 
1643 	err = populate_event_from_wobj(dev, &event, wobj);
1644 	if (err) {
1645 		dev_warn(dev, "Bad event data (ACPI type %d)\n", wobj->type);
1646 		goto out_free_wobj;
1647 	}
1648 
1649 	event_type = classify_event(event.name, event.category);
1650 	switch (event_type) {
1651 	case HP_WMI_TYPE_AIR_FLOW:
1652 		fan_info = match_fan_event(state, event.description);
1653 		if (fan_info)
1654 			fan_info->alarm = true;
1655 		break;
1656 
1657 	case HP_WMI_TYPE_INTRUSION:
1658 		state->intrusion = true;
1659 		break;
1660 
1661 	case HP_WMI_TYPE_TEMPERATURE:
1662 		count = match_temp_events(state, event.description, temp_info);
1663 		while (count)
1664 			temp_info[--count]->alarm = true;
1665 		break;
1666 
1667 	default:
1668 		break;
1669 	}
1670 
1671 out_free_wobj:
1672 	kfree(wobj);
1673 
1674 	devm_kfree(dev, event.name);
1675 	devm_kfree(dev, event.description);
1676 
1677 out_unlock:
1678 	mutex_unlock(&state->lock);
1679 }
1680 
1681 static int init_platform_events(struct device *dev,
1682 				struct hp_wmi_platform_events **out_pevents,
1683 				u8 *out_pcount)
1684 {
1685 	struct hp_wmi_platform_events *pevents_arr;
1686 	struct hp_wmi_platform_events *pevents;
1687 	union acpi_object *wobj;
1688 	u8 count;
1689 	int err;
1690 	u8 i;
1691 
1692 	count = hp_wmi_wobj_instance_count(HP_WMI_PLATFORM_EVENTS_GUID);
1693 	if (!count) {
1694 		*out_pcount = 0;
1695 
1696 		dev_dbg(dev, "No platform events\n");
1697 
1698 		return 0;
1699 	}
1700 
1701 	pevents_arr = devm_kcalloc(dev, count, sizeof(*pevents), GFP_KERNEL);
1702 	if (!pevents_arr)
1703 		return -ENOMEM;
1704 
1705 	for (i = 0, pevents = pevents_arr; i < count; i++, pevents++) {
1706 		wobj = hp_wmi_get_wobj(HP_WMI_PLATFORM_EVENTS_GUID, i);
1707 		if (!wobj)
1708 			return -EIO;
1709 
1710 		err = populate_platform_events_from_wobj(dev, pevents, wobj);
1711 
1712 		kfree(wobj);
1713 
1714 		if (err)
1715 			return err;
1716 	}
1717 
1718 	*out_pevents = pevents_arr;
1719 	*out_pcount = count;
1720 
1721 	dev_dbg(dev, "Found %u platform events\n", count);
1722 
1723 	return 0;
1724 }
1725 
1726 static int init_numeric_sensors(struct hp_wmi_sensors *state,
1727 				struct hp_wmi_info *connected[],
1728 				struct hp_wmi_info **out_info,
1729 				u8 *out_icount, u8 *out_count,
1730 				bool *out_is_new)
1731 {
1732 	struct hp_wmi_info ***info_map = state->info_map;
1733 	u8 *channel_count = state->channel_count;
1734 	struct device *dev = &state->wdev->dev;
1735 	struct hp_wmi_numeric_sensor *nsensor;
1736 	u8 channel_index[hwmon_max] = {};
1737 	enum hwmon_sensor_types type;
1738 	struct hp_wmi_info *info_arr;
1739 	struct hp_wmi_info *info;
1740 	union acpi_object *wobj;
1741 	u8 count = 0;
1742 	bool is_new;
1743 	u8 icount;
1744 	int wtype;
1745 	int err;
1746 	u8 c;
1747 	u8 i;
1748 
1749 	icount = hp_wmi_wobj_instance_count(HP_WMI_NUMERIC_SENSOR_GUID);
1750 	if (!icount)
1751 		return -ENODATA;
1752 
1753 	info_arr = devm_kcalloc(dev, icount, sizeof(*info), GFP_KERNEL);
1754 	if (!info_arr)
1755 		return -ENOMEM;
1756 
1757 	for (i = 0, info = info_arr; i < icount; i++, info++) {
1758 		wobj = hp_wmi_get_wobj(HP_WMI_NUMERIC_SENSOR_GUID, i);
1759 		if (!wobj)
1760 			return -EIO;
1761 
1762 		info->instance = i;
1763 		info->state = state;
1764 		nsensor = &info->nsensor;
1765 
1766 		err = populate_numeric_sensor_from_wobj(dev, nsensor, wobj,
1767 							&is_new);
1768 
1769 		kfree(wobj);
1770 
1771 		if (err)
1772 			return err;
1773 
1774 		if (!numeric_sensor_is_connected(nsensor))
1775 			continue;
1776 
1777 		wtype = classify_numeric_sensor(nsensor);
1778 		if (wtype < 0)
1779 			continue;
1780 
1781 		type = hp_wmi_hwmon_type_map[wtype];
1782 
1783 		channel_count[type]++;
1784 
1785 		info->type = type;
1786 
1787 		interpret_info(info);
1788 
1789 		connected[count++] = info;
1790 	}
1791 
1792 	dev_dbg(dev, "Found %u sensors (%u connected)\n", i, count);
1793 
1794 	for (i = 0; i < count; i++) {
1795 		info = connected[i];
1796 		type = info->type;
1797 		c = channel_index[type]++;
1798 
1799 		if (!info_map[type]) {
1800 			info_map[type] = devm_kcalloc(dev, channel_count[type],
1801 						      sizeof(*info_map),
1802 						      GFP_KERNEL);
1803 			if (!info_map[type])
1804 				return -ENOMEM;
1805 		}
1806 
1807 		info_map[type][c] = info;
1808 	}
1809 
1810 	*out_info = info_arr;
1811 	*out_icount = icount;
1812 	*out_count = count;
1813 	*out_is_new = is_new;
1814 
1815 	return 0;
1816 }
1817 
1818 static bool find_event_attributes(struct hp_wmi_sensors *state,
1819 				  struct hp_wmi_platform_events *pevents,
1820 				  u8 pevents_count)
1821 {
1822 	/*
1823 	 * The existence of this HPBIOS_PlatformEvents instance:
1824 	 *
1825 	 *   {
1826 	 *     Name = "Rear Chassis Fan0 Stall";
1827 	 *     Description = "Rear Chassis Fan0 Speed";
1828 	 *     Category = 3;           // "Sensor"
1829 	 *     PossibleSeverity = 25;  // "Critical Failure"
1830 	 *     PossibleStatus = 5;     // "Predictive Failure"
1831 	 *     [...]
1832 	 *   }
1833 	 *
1834 	 * means that this HPBIOS_BIOSEvent instance may occur:
1835 	 *
1836 	 *   {
1837 	 *     Name = "Rear Chassis Fan0 Stall";
1838 	 *     Description = "Rear Chassis Fan0 Speed";
1839 	 *     Category = 3;           // "Sensor"
1840 	 *     Severity = 25;          // "Critical Failure"
1841 	 *     Status = 5;             // "Predictive Failure"
1842 	 *   }
1843 	 *
1844 	 * After the event occurs (e.g. because the fan was unplugged),
1845 	 * polling the related HPBIOS_BIOSNumericSensor instance gives:
1846 	 *
1847 	 *   {
1848 	 *      Name = "Rear Chassis Fan0";
1849 	 *      Description = "Reports rear chassis fan0 speed";
1850 	 *      OperationalStatus = 5; // "Predictive Failure", was 3 ("OK")
1851 	 *      CurrentReading = 0;
1852 	 *      [...]
1853 	 *   }
1854 	 *
1855 	 * In this example, the hwmon fan channel for "Rear Chassis Fan0"
1856 	 * should support the alarm flag and have it be set if the related
1857 	 * HPBIOS_BIOSEvent instance occurs.
1858 	 *
1859 	 * In addition to fan events, temperature (CPU/chassis) and intrusion
1860 	 * events are relevant to hwmon [2]. Note that much information in [2]
1861 	 * is unreliable; it is referenced in addition to ACPI dumps [3] merely
1862 	 * to support the conclusion that sensor and event names/descriptions
1863 	 * are systematic enough to allow this driver to match them.
1864 	 *
1865 	 * Complications and limitations:
1866 	 *
1867 	 * - Strings are freeform and may vary, cf. sensor Name "CPU0 Fan"
1868 	 *   on a Z420 vs. "CPU Fan Speed" on an EliteOne 800 G1.
1869 	 * - Leading/trailing whitespace is a rare but real possibility [3].
1870 	 * - The HPBIOS_PlatformEvents object may not exist or its instances
1871 	 *   may show that the system only has e.g. BIOS setting-related
1872 	 *   events (cf. the ProBook 4540s and ProBook 470 G0 [3]).
1873 	 */
1874 
1875 	struct hp_wmi_info *temp_info[HP_WMI_MAX_INSTANCES] = {};
1876 	const char *event_description;
1877 	struct hp_wmi_info *fan_info;
1878 	bool has_events = false;
1879 	const char *event_name;
1880 	u32 event_category;
1881 	int event_type;
1882 	u8 count;
1883 	u8 i;
1884 
1885 	for (i = 0; i < pevents_count; i++, pevents++) {
1886 		event_name = pevents->name;
1887 		event_description = pevents->description;
1888 		event_category = pevents->category;
1889 
1890 		event_type = classify_event(event_name, event_category);
1891 		switch (event_type) {
1892 		case HP_WMI_TYPE_AIR_FLOW:
1893 			fan_info = match_fan_event(state, event_description);
1894 			if (!fan_info)
1895 				break;
1896 
1897 			fan_info->has_alarm = true;
1898 			has_events = true;
1899 			break;
1900 
1901 		case HP_WMI_TYPE_INTRUSION:
1902 			state->has_intrusion = true;
1903 			has_events = true;
1904 			break;
1905 
1906 		case HP_WMI_TYPE_TEMPERATURE:
1907 			count = match_temp_events(state, event_description,
1908 						  temp_info);
1909 			if (!count)
1910 				break;
1911 
1912 			while (count)
1913 				temp_info[--count]->has_alarm = true;
1914 			has_events = true;
1915 			break;
1916 
1917 		default:
1918 			break;
1919 		}
1920 	}
1921 
1922 	return has_events;
1923 }
1924 
1925 static int make_chip_info(struct hp_wmi_sensors *state, bool has_events)
1926 {
1927 	const struct hwmon_channel_info **ptr_channel_info;
1928 	struct hp_wmi_info ***info_map = state->info_map;
1929 	u8 *channel_count = state->channel_count;
1930 	struct hwmon_channel_info *channel_info;
1931 	struct device *dev = &state->wdev->dev;
1932 	enum hwmon_sensor_types type;
1933 	u8 type_count = 0;
1934 	u32 *config;
1935 	u32 attr;
1936 	u8 count;
1937 	u8 i;
1938 
1939 	if (channel_count[hwmon_temp])
1940 		channel_count[hwmon_chip] = 1;
1941 
1942 	if (has_events && state->has_intrusion)
1943 		channel_count[hwmon_intrusion] = 1;
1944 
1945 	for (type = hwmon_chip; type < hwmon_max; type++)
1946 		if (channel_count[type])
1947 			type_count++;
1948 
1949 	channel_info = devm_kcalloc(dev, type_count,
1950 				    sizeof(*channel_info), GFP_KERNEL);
1951 	if (!channel_info)
1952 		return -ENOMEM;
1953 
1954 	ptr_channel_info = devm_kcalloc(dev, type_count + 1,
1955 					sizeof(*ptr_channel_info), GFP_KERNEL);
1956 	if (!ptr_channel_info)
1957 		return -ENOMEM;
1958 
1959 	hp_wmi_chip_info.info = ptr_channel_info;
1960 
1961 	for (type = hwmon_chip; type < hwmon_max; type++) {
1962 		count = channel_count[type];
1963 		if (!count)
1964 			continue;
1965 
1966 		config = devm_kcalloc(dev, count + 1,
1967 				      sizeof(*config), GFP_KERNEL);
1968 		if (!config)
1969 			return -ENOMEM;
1970 
1971 		attr = hp_wmi_hwmon_attributes[type];
1972 		channel_info->type = type;
1973 		channel_info->config = config;
1974 		memset32(config, attr, count);
1975 
1976 		*ptr_channel_info++ = channel_info++;
1977 
1978 		if (!has_events || (type != hwmon_temp && type != hwmon_fan))
1979 			continue;
1980 
1981 		attr = type == hwmon_temp ? HWMON_T_ALARM : HWMON_F_ALARM;
1982 
1983 		for (i = 0; i < count; i++)
1984 			if (info_map[type][i]->has_alarm)
1985 				config[i] |= attr;
1986 	}
1987 
1988 	return 0;
1989 }
1990 
1991 static bool add_event_handler(struct hp_wmi_sensors *state)
1992 {
1993 	struct device *dev = &state->wdev->dev;
1994 	int err;
1995 
1996 	err = wmi_install_notify_handler(HP_WMI_EVENT_GUID,
1997 					 hp_wmi_notify, state);
1998 	if (err) {
1999 		dev_info(dev, "Failed to subscribe to WMI event\n");
2000 		return false;
2001 	}
2002 
2003 	err = devm_add_action_or_reset(dev, hp_wmi_devm_notify_remove, NULL);
2004 	if (err)
2005 		return false;
2006 
2007 	return true;
2008 }
2009 
2010 static int hp_wmi_sensors_init(struct hp_wmi_sensors *state)
2011 {
2012 	struct hp_wmi_info *connected[HP_WMI_MAX_INSTANCES];
2013 	struct hp_wmi_platform_events *pevents = NULL;
2014 	struct device *dev = &state->wdev->dev;
2015 	struct hp_wmi_info *info;
2016 	struct device *hwdev;
2017 	bool has_events;
2018 	bool is_new;
2019 	u8 icount;
2020 	u8 pcount;
2021 	u8 count;
2022 	int err;
2023 
2024 	err = init_platform_events(dev, &pevents, &pcount);
2025 	if (err)
2026 		return err;
2027 
2028 	err = init_numeric_sensors(state, connected, &info,
2029 				   &icount, &count, &is_new);
2030 	if (err)
2031 		return err;
2032 
2033 	if (IS_ENABLED(CONFIG_DEBUG_FS))
2034 		hp_wmi_debugfs_init(dev, info, pevents, icount, pcount, is_new);
2035 
2036 	if (!count)
2037 		return 0;	/* No connected sensors; debugfs only. */
2038 
2039 	has_events = find_event_attributes(state, pevents, pcount);
2040 
2041 	/* Survive failure to install WMI event handler. */
2042 	if (has_events && !add_event_handler(state))
2043 		has_events = false;
2044 
2045 	err = make_chip_info(state, has_events);
2046 	if (err)
2047 		return err;
2048 
2049 	hwdev = devm_hwmon_device_register_with_info(dev, "hp_wmi_sensors",
2050 						     state, &hp_wmi_chip_info,
2051 						     NULL);
2052 	return PTR_ERR_OR_ZERO(hwdev);
2053 }
2054 
2055 static int hp_wmi_sensors_probe(struct wmi_device *wdev, const void *context)
2056 {
2057 	struct device *dev = &wdev->dev;
2058 	struct hp_wmi_sensors *state;
2059 
2060 	state = devm_kzalloc(dev, sizeof(*state), GFP_KERNEL);
2061 	if (!state)
2062 		return -ENOMEM;
2063 
2064 	state->wdev = wdev;
2065 
2066 	mutex_init(&state->lock);
2067 
2068 	dev_set_drvdata(dev, state);
2069 
2070 	return hp_wmi_sensors_init(state);
2071 }
2072 
2073 static const struct wmi_device_id hp_wmi_sensors_id_table[] = {
2074 	{ HP_WMI_NUMERIC_SENSOR_GUID, NULL },
2075 	{},
2076 };
2077 
2078 static struct wmi_driver hp_wmi_sensors_driver = {
2079 	.driver   = { .name = "hp-wmi-sensors" },
2080 	.id_table = hp_wmi_sensors_id_table,
2081 	.probe    = hp_wmi_sensors_probe,
2082 };
2083 module_wmi_driver(hp_wmi_sensors_driver);
2084 
2085 MODULE_AUTHOR("James Seo <james@equiv.tech>");
2086 MODULE_DESCRIPTION("HP WMI Sensors driver");
2087 MODULE_LICENSE("GPL");
2088