xref: /openbmc/linux/drivers/hwmon/asus-ec-sensors.c (revision 09e02c8e632a1717e6ffaf352cfeb2840bc861d2)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * HWMON driver for ASUS motherboards that publish some sensor values
4  * via the embedded controller registers.
5  *
6  * Copyright (C) 2021 Eugene Shalygin <eugene.shalygin@gmail.com>
7 
8  * EC provides:
9  * - Chipset temperature
10  * - CPU temperature
11  * - Motherboard temperature
12  * - T_Sensor temperature
13  * - VRM temperature
14  * - Water In temperature
15  * - Water Out temperature
16  * - CPU Optional fan RPM
17  * - Chipset fan RPM
18  * - VRM Heat Sink fan RPM
19  * - Water Flow fan RPM
20  * - CPU current
21  * - CPU core voltage
22  */
23 
24 #include <linux/acpi.h>
25 #include <linux/bitops.h>
26 #include <linux/dev_printk.h>
27 #include <linux/dmi.h>
28 #include <linux/hwmon.h>
29 #include <linux/init.h>
30 #include <linux/jiffies.h>
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/platform_device.h>
34 #include <linux/sort.h>
35 #include <linux/units.h>
36 
37 #include <asm/unaligned.h>
38 
39 static char *mutex_path_override;
40 
41 /* Writing to this EC register switches EC bank */
42 #define ASUS_EC_BANK_REGISTER	0xff
43 #define SENSOR_LABEL_LEN	16
44 
45 /*
46  * Arbitrary set max. allowed bank number. Required for sorting banks and
47  * currently is overkill with just 2 banks used at max, but for the sake
48  * of alignment let's set it to a higher value.
49  */
50 #define ASUS_EC_MAX_BANK	3
51 
52 #define ACPI_LOCK_DELAY_MS	500
53 
54 /* ACPI mutex for locking access to the EC for the firmware */
55 #define ASUS_HW_ACCESS_MUTEX_ASMX	"\\AMW0.ASMX"
56 
57 #define MAX_IDENTICAL_BOARD_VARIATIONS	2
58 
59 /* Moniker for the ACPI global lock (':' is not allowed in ASL identifiers) */
60 #define ACPI_GLOBAL_LOCK_PSEUDO_PATH	":GLOBAL_LOCK"
61 
62 typedef union {
63 	u32 value;
64 	struct {
65 		u8 index;
66 		u8 bank;
67 		u8 size;
68 		u8 dummy;
69 	} components;
70 } sensor_address;
71 
72 #define MAKE_SENSOR_ADDRESS(size, bank, index) {                               \
73 		.value = (size << 16) + (bank << 8) + index                    \
74 	}
75 
76 static u32 hwmon_attributes[hwmon_max] = {
77 	[hwmon_chip] = HWMON_C_REGISTER_TZ,
78 	[hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL,
79 	[hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL,
80 	[hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL,
81 	[hwmon_fan] = HWMON_F_INPUT | HWMON_F_LABEL,
82 };
83 
84 struct ec_sensor_info {
85 	char label[SENSOR_LABEL_LEN];
86 	enum hwmon_sensor_types type;
87 	sensor_address addr;
88 };
89 
90 #define EC_SENSOR(sensor_label, sensor_type, size, bank, index) {              \
91 		.label = sensor_label, .type = sensor_type,                    \
92 		.addr = MAKE_SENSOR_ADDRESS(size, bank, index),                \
93 	}
94 
95 enum ec_sensors {
96 	/* chipset temperature [℃] */
97 	ec_sensor_temp_chipset,
98 	/* CPU temperature [℃] */
99 	ec_sensor_temp_cpu,
100 	/* motherboard temperature [℃] */
101 	ec_sensor_temp_mb,
102 	/* "T_Sensor" temperature sensor reading [℃] */
103 	ec_sensor_temp_t_sensor,
104 	/* VRM temperature [℃] */
105 	ec_sensor_temp_vrm,
106 	/* CPU Core voltage [mV] */
107 	ec_sensor_in_cpu_core,
108 	/* CPU_Opt fan [RPM] */
109 	ec_sensor_fan_cpu_opt,
110 	/* VRM heat sink fan [RPM] */
111 	ec_sensor_fan_vrm_hs,
112 	/* Chipset fan [RPM] */
113 	ec_sensor_fan_chipset,
114 	/* Water flow sensor reading [RPM] */
115 	ec_sensor_fan_water_flow,
116 	/* CPU current [A] */
117 	ec_sensor_curr_cpu,
118 	/* "Water_In" temperature sensor reading [℃] */
119 	ec_sensor_temp_water_in,
120 	/* "Water_Out" temperature sensor reading [℃] */
121 	ec_sensor_temp_water_out,
122 };
123 
124 #define SENSOR_TEMP_CHIPSET BIT(ec_sensor_temp_chipset)
125 #define SENSOR_TEMP_CPU BIT(ec_sensor_temp_cpu)
126 #define SENSOR_TEMP_MB BIT(ec_sensor_temp_mb)
127 #define SENSOR_TEMP_T_SENSOR BIT(ec_sensor_temp_t_sensor)
128 #define SENSOR_TEMP_VRM BIT(ec_sensor_temp_vrm)
129 #define SENSOR_IN_CPU_CORE BIT(ec_sensor_in_cpu_core)
130 #define SENSOR_FAN_CPU_OPT BIT(ec_sensor_fan_cpu_opt)
131 #define SENSOR_FAN_VRM_HS BIT(ec_sensor_fan_vrm_hs)
132 #define SENSOR_FAN_CHIPSET BIT(ec_sensor_fan_chipset)
133 #define SENSOR_FAN_WATER_FLOW BIT(ec_sensor_fan_water_flow)
134 #define SENSOR_CURR_CPU BIT(ec_sensor_curr_cpu)
135 #define SENSOR_TEMP_WATER_IN BIT(ec_sensor_temp_water_in)
136 #define SENSOR_TEMP_WATER_OUT BIT(ec_sensor_temp_water_out)
137 
138 enum board_family {
139 	family_unknown,
140 	family_amd_400_series,
141 	family_amd_500_series,
142 };
143 
144 /* All the known sensors for ASUS EC controllers */
145 static const struct ec_sensor_info sensors_family_amd_400[] = {
146 	[ec_sensor_temp_chipset] =
147 		EC_SENSOR("Chipset", hwmon_temp, 1, 0x00, 0x3a),
148 	[ec_sensor_temp_cpu] =
149 		EC_SENSOR("CPU", hwmon_temp, 1, 0x00, 0x3b),
150 	[ec_sensor_temp_mb] =
151 		EC_SENSOR("Motherboard", hwmon_temp, 1, 0x00, 0x3c),
152 	[ec_sensor_temp_t_sensor] =
153 		EC_SENSOR("T_Sensor", hwmon_temp, 1, 0x00, 0x3d),
154 	[ec_sensor_temp_vrm] =
155 		EC_SENSOR("VRM", hwmon_temp, 1, 0x00, 0x3e),
156 	[ec_sensor_in_cpu_core] =
157 		EC_SENSOR("CPU Core", hwmon_in, 2, 0x00, 0xa2),
158 	[ec_sensor_fan_cpu_opt] =
159 		EC_SENSOR("CPU_Opt", hwmon_fan, 2, 0x00, 0xbc),
160 	[ec_sensor_fan_vrm_hs] =
161 		EC_SENSOR("VRM HS", hwmon_fan, 2, 0x00, 0xb2),
162 	[ec_sensor_fan_chipset] =
163 		/* no chipset fans in this generation */
164 		EC_SENSOR("Chipset", hwmon_fan, 0, 0x00, 0x00),
165 	[ec_sensor_fan_water_flow] =
166 		EC_SENSOR("Water_Flow", hwmon_fan, 2, 0x00, 0xb4),
167 	[ec_sensor_curr_cpu] =
168 		EC_SENSOR("CPU", hwmon_curr, 1, 0x00, 0xf4),
169 	[ec_sensor_temp_water_in] =
170 		EC_SENSOR("Water_In", hwmon_temp, 1, 0x01, 0x0d),
171 	[ec_sensor_temp_water_out] =
172 		EC_SENSOR("Water_Out", hwmon_temp, 1, 0x01, 0x0b),
173 };
174 
175 static const struct ec_sensor_info sensors_family_amd_500[] = {
176 	[ec_sensor_temp_chipset] =
177 		EC_SENSOR("Chipset", hwmon_temp, 1, 0x00, 0x3a),
178 	[ec_sensor_temp_cpu] = EC_SENSOR("CPU", hwmon_temp, 1, 0x00, 0x3b),
179 	[ec_sensor_temp_mb] =
180 		EC_SENSOR("Motherboard", hwmon_temp, 1, 0x00, 0x3c),
181 	[ec_sensor_temp_t_sensor] =
182 		EC_SENSOR("T_Sensor", hwmon_temp, 1, 0x00, 0x3d),
183 	[ec_sensor_temp_vrm] = EC_SENSOR("VRM", hwmon_temp, 1, 0x00, 0x3e),
184 	[ec_sensor_in_cpu_core] =
185 		EC_SENSOR("CPU Core", hwmon_in, 2, 0x00, 0xa2),
186 	[ec_sensor_fan_cpu_opt] =
187 		EC_SENSOR("CPU_Opt", hwmon_fan, 2, 0x00, 0xb0),
188 	[ec_sensor_fan_vrm_hs] = EC_SENSOR("VRM HS", hwmon_fan, 2, 0x00, 0xb2),
189 	[ec_sensor_fan_chipset] =
190 		EC_SENSOR("Chipset", hwmon_fan, 2, 0x00, 0xb4),
191 	[ec_sensor_fan_water_flow] =
192 		EC_SENSOR("Water_Flow", hwmon_fan, 2, 0x00, 0xbc),
193 	[ec_sensor_curr_cpu] = EC_SENSOR("CPU", hwmon_curr, 1, 0x00, 0xf4),
194 	[ec_sensor_temp_water_in] =
195 		EC_SENSOR("Water_In", hwmon_temp, 1, 0x01, 0x00),
196 	[ec_sensor_temp_water_out] =
197 		EC_SENSOR("Water_Out", hwmon_temp, 1, 0x01, 0x01),
198 };
199 
200 /* Shortcuts for common combinations */
201 #define SENSOR_SET_TEMP_CHIPSET_CPU_MB                                         \
202 	(SENSOR_TEMP_CHIPSET | SENSOR_TEMP_CPU | SENSOR_TEMP_MB)
203 #define SENSOR_SET_TEMP_WATER (SENSOR_TEMP_WATER_IN | SENSOR_TEMP_WATER_OUT)
204 
205 struct ec_board_info {
206 	const char *board_names[MAX_IDENTICAL_BOARD_VARIATIONS];
207 	unsigned long sensors;
208 	/*
209 	 * Defines which mutex to use for guarding access to the state and the
210 	 * hardware. Can be either a full path to an AML mutex or the
211 	 * pseudo-path ACPI_GLOBAL_LOCK_PSEUDO_PATH to use the global ACPI lock,
212 	 * or left empty to use a regular mutex object, in which case access to
213 	 * the hardware is not guarded.
214 	 */
215 	const char *mutex_path;
216 	enum board_family family;
217 };
218 
219 static const struct ec_board_info board_info[] = {
220 	{
221 		.board_names = {"PRIME X470-PRO"},
222 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
223 			SENSOR_TEMP_T_SENSOR | SENSOR_TEMP_VRM |
224 			SENSOR_FAN_CPU_OPT |
225 			SENSOR_CURR_CPU | SENSOR_IN_CPU_CORE,
226 		.mutex_path = ACPI_GLOBAL_LOCK_PSEUDO_PATH,
227 		.family = family_amd_400_series,
228 	},
229 	{
230 		.board_names = {"PRIME X570-PRO"},
231 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB | SENSOR_TEMP_VRM |
232 			SENSOR_TEMP_T_SENSOR | SENSOR_FAN_CHIPSET,
233 		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
234 		.family = family_amd_500_series,
235 	},
236 	{
237 		.board_names = {"ProArt X570-CREATOR WIFI"},
238 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB | SENSOR_TEMP_VRM |
239 			SENSOR_TEMP_T_SENSOR | SENSOR_FAN_CPU_OPT |
240 			SENSOR_CURR_CPU | SENSOR_IN_CPU_CORE,
241 	},
242 	{
243 		.board_names = {"Pro WS X570-ACE"},
244 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB | SENSOR_TEMP_VRM |
245 			SENSOR_TEMP_T_SENSOR | SENSOR_FAN_CHIPSET |
246 			SENSOR_CURR_CPU | SENSOR_IN_CPU_CORE,
247 		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
248 		.family = family_amd_500_series,
249 	},
250 	{
251 		.board_names = {"ROG CROSSHAIR VIII DARK HERO"},
252 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
253 			SENSOR_TEMP_T_SENSOR |
254 			SENSOR_TEMP_VRM | SENSOR_SET_TEMP_WATER |
255 			SENSOR_FAN_CPU_OPT | SENSOR_FAN_WATER_FLOW |
256 			SENSOR_CURR_CPU | SENSOR_IN_CPU_CORE,
257 		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
258 		.family = family_amd_500_series,
259 	},
260 	{
261 		.board_names = {"ROG CROSSHAIR VIII FORMULA"},
262 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
263 			SENSOR_TEMP_T_SENSOR | SENSOR_TEMP_VRM |
264 			SENSOR_FAN_CPU_OPT | SENSOR_FAN_CHIPSET |
265 			SENSOR_CURR_CPU | SENSOR_IN_CPU_CORE,
266 		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
267 		.family = family_amd_500_series,
268 	},
269 	{
270 		.board_names = {
271 			"ROG CROSSHAIR VIII HERO",
272 			"ROG CROSSHAIR VIII HERO (WI-FI)",
273 		},
274 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
275 			SENSOR_TEMP_T_SENSOR |
276 			SENSOR_TEMP_VRM | SENSOR_SET_TEMP_WATER |
277 			SENSOR_FAN_CPU_OPT | SENSOR_FAN_CHIPSET |
278 			SENSOR_FAN_WATER_FLOW | SENSOR_CURR_CPU |
279 			SENSOR_IN_CPU_CORE,
280 		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
281 		.family = family_amd_500_series,
282 	},
283 	{
284 		.board_names = {"ROG CROSSHAIR VIII IMPACT"},
285 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
286 			SENSOR_TEMP_T_SENSOR | SENSOR_TEMP_VRM |
287 			SENSOR_FAN_CHIPSET | SENSOR_CURR_CPU |
288 			SENSOR_IN_CPU_CORE,
289 		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
290 		.family = family_amd_500_series,
291 	},
292 	{
293 		.board_names = {"ROG STRIX B550-E GAMING"},
294 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
295 			SENSOR_TEMP_T_SENSOR | SENSOR_TEMP_VRM |
296 			SENSOR_FAN_CPU_OPT,
297 		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
298 		.family = family_amd_500_series,
299 	},
300 	{
301 		.board_names = {"ROG STRIX B550-I GAMING"},
302 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
303 			SENSOR_TEMP_T_SENSOR | SENSOR_TEMP_VRM |
304 			SENSOR_FAN_VRM_HS | SENSOR_CURR_CPU |
305 			SENSOR_IN_CPU_CORE,
306 		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
307 		.family = family_amd_500_series,
308 	},
309 	{
310 		.board_names = {"ROG STRIX X570-E GAMING"},
311 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
312 			SENSOR_TEMP_T_SENSOR | SENSOR_TEMP_VRM |
313 			SENSOR_FAN_CHIPSET | SENSOR_CURR_CPU |
314 			SENSOR_IN_CPU_CORE,
315 		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
316 		.family = family_amd_500_series,
317 	},
318 	{
319 		.board_names = {"ROG STRIX X570-E GAMING WIFI II"},
320 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
321 			SENSOR_TEMP_T_SENSOR | SENSOR_CURR_CPU |
322 			SENSOR_IN_CPU_CORE,
323 		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
324 		.family = family_amd_500_series,
325 	},
326 	{
327 		.board_names = {"ROG STRIX X570-F GAMING"},
328 		.sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
329 			SENSOR_TEMP_T_SENSOR | SENSOR_FAN_CHIPSET,
330 		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
331 		.family = family_amd_500_series,
332 	},
333 	{
334 		.board_names = {"ROG STRIX X570-I GAMING"},
335 		.sensors = SENSOR_TEMP_T_SENSOR | SENSOR_FAN_VRM_HS |
336 			SENSOR_FAN_CHIPSET | SENSOR_CURR_CPU |
337 			SENSOR_IN_CPU_CORE,
338 		.mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
339 		.family = family_amd_500_series,
340 	},
341 	{}
342 };
343 
344 struct ec_sensor {
345 	unsigned int info_index;
346 	s32 cached_value;
347 };
348 
349 struct lock_data {
350 	union {
351 		acpi_handle aml;
352 		/* global lock handle */
353 		u32 glk;
354 	} mutex;
355 	bool (*lock)(struct lock_data *data);
356 	bool (*unlock)(struct lock_data *data);
357 };
358 
359 /*
360  * The next function pairs implement options for locking access to the
361  * state and the EC
362  */
363 static bool lock_via_acpi_mutex(struct lock_data *data)
364 {
365 	/*
366 	 * ASUS DSDT does not specify that access to the EC has to be guarded,
367 	 * but firmware does access it via ACPI
368 	 */
369 	return ACPI_SUCCESS(acpi_acquire_mutex(data->mutex.aml,
370 					       NULL, ACPI_LOCK_DELAY_MS));
371 }
372 
373 static bool unlock_acpi_mutex(struct lock_data *data)
374 {
375 	return ACPI_SUCCESS(acpi_release_mutex(data->mutex.aml, NULL));
376 }
377 
378 static bool lock_via_global_acpi_lock(struct lock_data *data)
379 {
380 	return ACPI_SUCCESS(acpi_acquire_global_lock(ACPI_LOCK_DELAY_MS,
381 						     &data->mutex.glk));
382 }
383 
384 static bool unlock_global_acpi_lock(struct lock_data *data)
385 {
386 	return ACPI_SUCCESS(acpi_release_global_lock(data->mutex.glk));
387 }
388 
389 struct ec_sensors_data {
390 	const struct ec_board_info *board_info;
391 	const struct ec_sensor_info *sensors_info;
392 	struct ec_sensor *sensors;
393 	/* EC registers to read from */
394 	u16 *registers;
395 	u8 *read_buffer;
396 	/* sorted list of unique register banks */
397 	u8 banks[ASUS_EC_MAX_BANK + 1];
398 	/* in jiffies */
399 	unsigned long last_updated;
400 	struct lock_data lock_data;
401 	/* number of board EC sensors */
402 	u8 nr_sensors;
403 	/*
404 	 * number of EC registers to read
405 	 * (sensor might span more than 1 register)
406 	 */
407 	u8 nr_registers;
408 	/* number of unique register banks */
409 	u8 nr_banks;
410 };
411 
412 static u8 register_bank(u16 reg)
413 {
414 	return reg >> 8;
415 }
416 
417 static u8 register_index(u16 reg)
418 {
419 	return reg & 0x00ff;
420 }
421 
422 static bool is_sensor_data_signed(const struct ec_sensor_info *si)
423 {
424 	/*
425 	 * guessed from WMI functions in DSDT code for boards
426 	 * of the X470 generation
427 	 */
428 	return si->type == hwmon_temp;
429 }
430 
431 static const struct ec_sensor_info *
432 get_sensor_info(const struct ec_sensors_data *state, int index)
433 {
434 	return state->sensors_info + state->sensors[index].info_index;
435 }
436 
437 static int find_ec_sensor_index(const struct ec_sensors_data *ec,
438 				enum hwmon_sensor_types type, int channel)
439 {
440 	unsigned int i;
441 
442 	for (i = 0; i < ec->nr_sensors; i++) {
443 		if (get_sensor_info(ec, i)->type == type) {
444 			if (channel == 0)
445 				return i;
446 			channel--;
447 		}
448 	}
449 	return -ENOENT;
450 }
451 
452 static int __init bank_compare(const void *a, const void *b)
453 {
454 	return *((const s8 *)a) - *((const s8 *)b);
455 }
456 
457 static void __init setup_sensor_data(struct ec_sensors_data *ec)
458 {
459 	struct ec_sensor *s = ec->sensors;
460 	bool bank_found;
461 	int i, j;
462 	u8 bank;
463 
464 	ec->nr_banks = 0;
465 	ec->nr_registers = 0;
466 
467 	for_each_set_bit(i, &ec->board_info->sensors,
468 			 BITS_PER_TYPE(ec->board_info->sensors)) {
469 		s->info_index = i;
470 		s->cached_value = 0;
471 		ec->nr_registers +=
472 			ec->sensors_info[s->info_index].addr.components.size;
473 		bank_found = false;
474 		bank = ec->sensors_info[s->info_index].addr.components.bank;
475 		for (j = 0; j < ec->nr_banks; j++) {
476 			if (ec->banks[j] == bank) {
477 				bank_found = true;
478 				break;
479 			}
480 		}
481 		if (!bank_found) {
482 			ec->banks[ec->nr_banks++] = bank;
483 		}
484 		s++;
485 	}
486 	sort(ec->banks, ec->nr_banks, 1, bank_compare, NULL);
487 }
488 
489 static void __init fill_ec_registers(struct ec_sensors_data *ec)
490 {
491 	const struct ec_sensor_info *si;
492 	unsigned int i, j, register_idx = 0;
493 
494 	for (i = 0; i < ec->nr_sensors; ++i) {
495 		si = get_sensor_info(ec, i);
496 		for (j = 0; j < si->addr.components.size; ++j, ++register_idx) {
497 			ec->registers[register_idx] =
498 				(si->addr.components.bank << 8) +
499 				si->addr.components.index + j;
500 		}
501 	}
502 }
503 
504 static int __init setup_lock_data(struct device *dev)
505 {
506 	const char *mutex_path;
507 	int status;
508 	struct ec_sensors_data *state = dev_get_drvdata(dev);
509 
510 	mutex_path = mutex_path_override ?
511 		mutex_path_override : state->board_info->mutex_path;
512 
513 	if (!mutex_path || !strlen(mutex_path)) {
514 		dev_err(dev, "Hardware access guard mutex name is empty");
515 		return -EINVAL;
516 	}
517 	if (!strcmp(mutex_path, ACPI_GLOBAL_LOCK_PSEUDO_PATH)) {
518 		state->lock_data.mutex.glk = 0;
519 		state->lock_data.lock = lock_via_global_acpi_lock;
520 		state->lock_data.unlock = unlock_global_acpi_lock;
521 	} else {
522 		status = acpi_get_handle(NULL, (acpi_string)mutex_path,
523 					 &state->lock_data.mutex.aml);
524 		if (ACPI_FAILURE(status)) {
525 			dev_err(dev,
526 				"Failed to get hardware access guard AML mutex '%s': error %d",
527 				mutex_path, status);
528 			return -ENOENT;
529 		}
530 		state->lock_data.lock = lock_via_acpi_mutex;
531 		state->lock_data.unlock = unlock_acpi_mutex;
532 	}
533 	return 0;
534 }
535 
536 static int asus_ec_bank_switch(u8 bank, u8 *old)
537 {
538 	int status = 0;
539 
540 	if (old) {
541 		status = ec_read(ASUS_EC_BANK_REGISTER, old);
542 	}
543 	if (status || (old && (*old == bank)))
544 		return status;
545 	return ec_write(ASUS_EC_BANK_REGISTER, bank);
546 }
547 
548 static int asus_ec_block_read(const struct device *dev,
549 			      struct ec_sensors_data *ec)
550 {
551 	int ireg, ibank, status;
552 	u8 bank, reg_bank, prev_bank;
553 
554 	bank = 0;
555 	status = asus_ec_bank_switch(bank, &prev_bank);
556 	if (status) {
557 		dev_warn(dev, "EC bank switch failed");
558 		return status;
559 	}
560 
561 	if (prev_bank) {
562 		/* oops... somebody else is working with the EC too */
563 		dev_warn(dev,
564 			"Concurrent access to the ACPI EC detected.\nRace condition possible.");
565 	}
566 
567 	/* read registers minimizing bank switches. */
568 	for (ibank = 0; ibank < ec->nr_banks; ibank++) {
569 		if (bank != ec->banks[ibank]) {
570 			bank = ec->banks[ibank];
571 			if (asus_ec_bank_switch(bank, NULL)) {
572 				dev_warn(dev, "EC bank switch to %d failed",
573 					 bank);
574 				break;
575 			}
576 		}
577 		for (ireg = 0; ireg < ec->nr_registers; ireg++) {
578 			reg_bank = register_bank(ec->registers[ireg]);
579 			if (reg_bank < bank) {
580 				continue;
581 			}
582 			ec_read(register_index(ec->registers[ireg]),
583 				ec->read_buffer + ireg);
584 		}
585 	}
586 
587 	status = asus_ec_bank_switch(prev_bank, NULL);
588 	return status;
589 }
590 
591 static inline s32 get_sensor_value(const struct ec_sensor_info *si, u8 *data)
592 {
593 	if (is_sensor_data_signed(si)) {
594 		switch (si->addr.components.size) {
595 		case 1:
596 			return (s8)*data;
597 		case 2:
598 			return (s16)get_unaligned_be16(data);
599 		case 4:
600 			return (s32)get_unaligned_be32(data);
601 		default:
602 			return 0;
603 		}
604 	} else {
605 		switch (si->addr.components.size) {
606 		case 1:
607 			return *data;
608 		case 2:
609 			return get_unaligned_be16(data);
610 		case 4:
611 			return get_unaligned_be32(data);
612 		default:
613 			return 0;
614 		}
615 	}
616 }
617 
618 static void update_sensor_values(struct ec_sensors_data *ec, u8 *data)
619 {
620 	const struct ec_sensor_info *si;
621 	struct ec_sensor *s, *sensor_end;
622 
623 	sensor_end = ec->sensors + ec->nr_sensors;
624 	for (s = ec->sensors; s != sensor_end; s++) {
625 		si = ec->sensors_info + s->info_index;
626 		s->cached_value = get_sensor_value(si, data);
627 		data += si->addr.components.size;
628 	}
629 }
630 
631 static int update_ec_sensors(const struct device *dev,
632 			     struct ec_sensors_data *ec)
633 {
634 	int status;
635 
636 	if (!ec->lock_data.lock(&ec->lock_data)) {
637 		dev_warn(dev, "Failed to acquire mutex");
638 		return -EBUSY;
639 	}
640 
641 	status = asus_ec_block_read(dev, ec);
642 
643 	if (!status) {
644 		update_sensor_values(ec, ec->read_buffer);
645 	}
646 
647 	if (!ec->lock_data.unlock(&ec->lock_data))
648 		dev_err(dev, "Failed to release mutex");
649 
650 	return status;
651 }
652 
653 static long scale_sensor_value(s32 value, int data_type)
654 {
655 	switch (data_type) {
656 	case hwmon_curr:
657 	case hwmon_temp:
658 		return value * MILLI;
659 	default:
660 		return value;
661 	}
662 }
663 
664 static int get_cached_value_or_update(const struct device *dev,
665 				      int sensor_index,
666 				      struct ec_sensors_data *state, s32 *value)
667 {
668 	if (time_after(jiffies, state->last_updated + HZ)) {
669 		if (update_ec_sensors(dev, state)) {
670 			dev_err(dev, "update_ec_sensors() failure\n");
671 			return -EIO;
672 		}
673 
674 		state->last_updated = jiffies;
675 	}
676 
677 	*value = state->sensors[sensor_index].cached_value;
678 	return 0;
679 }
680 
681 /*
682  * Now follow the functions that implement the hwmon interface
683  */
684 
685 static int asus_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
686 			      u32 attr, int channel, long *val)
687 {
688 	int ret;
689 	s32 value = 0;
690 
691 	struct ec_sensors_data *state = dev_get_drvdata(dev);
692 	int sidx = find_ec_sensor_index(state, type, channel);
693 
694 	if (sidx < 0) {
695 		return sidx;
696 	}
697 
698 	ret = get_cached_value_or_update(dev, sidx, state, &value);
699 	if (!ret) {
700 		*val = scale_sensor_value(value,
701 					  get_sensor_info(state, sidx)->type);
702 	}
703 
704 	return ret;
705 }
706 
707 static int asus_ec_hwmon_read_string(struct device *dev,
708 				     enum hwmon_sensor_types type, u32 attr,
709 				     int channel, const char **str)
710 {
711 	struct ec_sensors_data *state = dev_get_drvdata(dev);
712 	int sensor_index = find_ec_sensor_index(state, type, channel);
713 	*str = get_sensor_info(state, sensor_index)->label;
714 
715 	return 0;
716 }
717 
718 static umode_t asus_ec_hwmon_is_visible(const void *drvdata,
719 					enum hwmon_sensor_types type, u32 attr,
720 					int channel)
721 {
722 	const struct ec_sensors_data *state = drvdata;
723 
724 	return find_ec_sensor_index(state, type, channel) >= 0 ? S_IRUGO : 0;
725 }
726 
727 static int __init
728 asus_ec_hwmon_add_chan_info(struct hwmon_channel_info *asus_ec_hwmon_chan,
729 			     struct device *dev, int num,
730 			     enum hwmon_sensor_types type, u32 config)
731 {
732 	int i;
733 	u32 *cfg = devm_kcalloc(dev, num + 1, sizeof(*cfg), GFP_KERNEL);
734 
735 	if (!cfg)
736 		return -ENOMEM;
737 
738 	asus_ec_hwmon_chan->type = type;
739 	asus_ec_hwmon_chan->config = cfg;
740 	for (i = 0; i < num; i++, cfg++)
741 		*cfg = config;
742 
743 	return 0;
744 }
745 
746 static const struct hwmon_ops asus_ec_hwmon_ops = {
747 	.is_visible = asus_ec_hwmon_is_visible,
748 	.read = asus_ec_hwmon_read,
749 	.read_string = asus_ec_hwmon_read_string,
750 };
751 
752 static struct hwmon_chip_info asus_ec_chip_info = {
753 	.ops = &asus_ec_hwmon_ops,
754 };
755 
756 static const struct ec_board_info * __init get_board_info(void)
757 {
758 	const char *dmi_board_vendor = dmi_get_system_info(DMI_BOARD_VENDOR);
759 	const char *dmi_board_name = dmi_get_system_info(DMI_BOARD_NAME);
760 	const struct ec_board_info *board;
761 
762 	if (!dmi_board_vendor || !dmi_board_name ||
763 	    strcasecmp(dmi_board_vendor, "ASUSTeK COMPUTER INC."))
764 		return NULL;
765 
766 	for (board = board_info; board->sensors; board++) {
767 		if (match_string(board->board_names,
768 				 MAX_IDENTICAL_BOARD_VARIATIONS,
769 				 dmi_board_name) >= 0)
770 			return board;
771 	}
772 
773 	return NULL;
774 }
775 
776 static int __init asus_ec_probe(struct platform_device *pdev)
777 {
778 	const struct hwmon_channel_info **ptr_asus_ec_ci;
779 	int nr_count[hwmon_max] = { 0 }, nr_types = 0;
780 	struct hwmon_channel_info *asus_ec_hwmon_chan;
781 	const struct ec_board_info *pboard_info;
782 	const struct hwmon_chip_info *chip_info;
783 	struct device *dev = &pdev->dev;
784 	struct ec_sensors_data *ec_data;
785 	const struct ec_sensor_info *si;
786 	enum hwmon_sensor_types type;
787 	struct device *hwdev;
788 	unsigned int i;
789 	int status;
790 
791 	pboard_info = get_board_info();
792 	if (!pboard_info)
793 		return -ENODEV;
794 
795 	ec_data = devm_kzalloc(dev, sizeof(struct ec_sensors_data),
796 			       GFP_KERNEL);
797 	if (!ec_data)
798 		return -ENOMEM;
799 
800 	dev_set_drvdata(dev, ec_data);
801 	ec_data->board_info = pboard_info;
802 
803 	switch (ec_data->board_info->family) {
804 	case family_amd_400_series:
805 		ec_data->sensors_info = sensors_family_amd_400;
806 		break;
807 	case family_amd_500_series:
808 		ec_data->sensors_info = sensors_family_amd_500;
809 		break;
810 	default:
811 		dev_err(dev, "Unknown board family: %d",
812 			ec_data->board_info->family);
813 		return -EINVAL;
814 	}
815 
816 	ec_data->nr_sensors = hweight_long(ec_data->board_info->sensors);
817 	ec_data->sensors = devm_kcalloc(dev, ec_data->nr_sensors,
818 					sizeof(struct ec_sensor), GFP_KERNEL);
819 
820 	status = setup_lock_data(dev);
821 	if (status) {
822 		dev_err(dev, "Failed to setup state/EC locking: %d", status);
823 		return status;
824 	}
825 
826 	setup_sensor_data(ec_data);
827 	ec_data->registers = devm_kcalloc(dev, ec_data->nr_registers,
828 					  sizeof(u16), GFP_KERNEL);
829 	ec_data->read_buffer = devm_kcalloc(dev, ec_data->nr_registers,
830 					    sizeof(u8), GFP_KERNEL);
831 
832 	if (!ec_data->registers || !ec_data->read_buffer)
833 		return -ENOMEM;
834 
835 	fill_ec_registers(ec_data);
836 
837 	for (i = 0; i < ec_data->nr_sensors; ++i) {
838 		si = get_sensor_info(ec_data, i);
839 		if (!nr_count[si->type])
840 			++nr_types;
841 		++nr_count[si->type];
842 	}
843 
844 	if (nr_count[hwmon_temp])
845 		nr_count[hwmon_chip]++, nr_types++;
846 
847 	asus_ec_hwmon_chan = devm_kcalloc(
848 		dev, nr_types, sizeof(*asus_ec_hwmon_chan), GFP_KERNEL);
849 	if (!asus_ec_hwmon_chan)
850 		return -ENOMEM;
851 
852 	ptr_asus_ec_ci = devm_kcalloc(dev, nr_types + 1,
853 				       sizeof(*ptr_asus_ec_ci), GFP_KERNEL);
854 	if (!ptr_asus_ec_ci)
855 		return -ENOMEM;
856 
857 	asus_ec_chip_info.info = ptr_asus_ec_ci;
858 	chip_info = &asus_ec_chip_info;
859 
860 	for (type = 0; type < hwmon_max; ++type) {
861 		if (!nr_count[type])
862 			continue;
863 
864 		asus_ec_hwmon_add_chan_info(asus_ec_hwmon_chan, dev,
865 					     nr_count[type], type,
866 					     hwmon_attributes[type]);
867 		*ptr_asus_ec_ci++ = asus_ec_hwmon_chan++;
868 	}
869 
870 	dev_info(dev, "board has %d EC sensors that span %d registers",
871 		 ec_data->nr_sensors, ec_data->nr_registers);
872 
873 	hwdev = devm_hwmon_device_register_with_info(dev, "asusec",
874 						     ec_data, chip_info, NULL);
875 
876 	return PTR_ERR_OR_ZERO(hwdev);
877 }
878 
879 
880 static const struct acpi_device_id acpi_ec_ids[] = {
881 	/* Embedded Controller Device */
882 	{ "PNP0C09", 0 },
883 	{}
884 };
885 
886 static struct platform_driver asus_ec_sensors_platform_driver = {
887 	.driver = {
888 		.name	= "asus-ec-sensors",
889 		.acpi_match_table = acpi_ec_ids,
890 	},
891 };
892 
893 MODULE_DEVICE_TABLE(acpi, acpi_ec_ids);
894 /*
895  * we use module_platform_driver_probe() rather than module_platform_driver()
896  * because the probe function (and its dependants) are marked with __init, which
897  * means we can't put it into the .probe member of the platform_driver struct
898  * above, and we can't mark the asus_ec_sensors_platform_driver object as __init
899  * because the object is referenced from the module exit code.
900  */
901 module_platform_driver_probe(asus_ec_sensors_platform_driver, asus_ec_probe);
902 
903 module_param_named(mutex_path, mutex_path_override, charp, 0);
904 MODULE_PARM_DESC(mutex_path,
905 		 "Override ACPI mutex path used to guard access to hardware");
906 
907 MODULE_AUTHOR("Eugene Shalygin <eugene.shalygin@gmail.com>");
908 MODULE_DESCRIPTION(
909 	"HWMON driver for sensors accessible via ACPI EC in ASUS motherboards");
910 MODULE_LICENSE("GPL");
911