xref: /linux/drivers/hwmon/cros_ec_hwmon.c (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  ChromeOS EC driver for hwmon
4  *
5  *  Copyright (C) 2024 Thomas Weißschuh <linux@weissschuh.net>
6  */
7 
8 #include <linux/cleanup.h>
9 #include <linux/device.h>
10 #include <linux/hwmon.h>
11 #include <linux/math.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/platform_data/cros_ec_commands.h>
15 #include <linux/platform_data/cros_ec_proto.h>
16 #include <linux/thermal.h>
17 #include <linux/types.h>
18 #include <linux/units.h>
19 
20 #define DRV_NAME	"cros-ec-hwmon"
21 
22 #define CROS_EC_HWMON_PWM_GET_FAN_DUTY_CMD_VERSION	0
23 #define CROS_EC_HWMON_PWM_SET_FAN_DUTY_CMD_VERSION	1
24 #define CROS_EC_HWMON_THERMAL_AUTO_FAN_CTRL_CMD_VERSION	2
25 
26 struct cros_ec_hwmon_priv {
27 	struct cros_ec_device *cros_ec;
28 	struct device *hwmon_dev;
29 	const char *temp_sensor_names[EC_TEMP_SENSOR_ENTRIES + EC_TEMP_SENSOR_B_ENTRIES];
30 	u8 usable_fans;
31 	bool fan_control_supported;
32 	bool temp_threshold_supported;
33 	u8 manual_fans; /* bits to indicate whether the fan is set to manual */
34 	u8 manual_fan_pwm[EC_FAN_SPEED_ENTRIES];
35 };
36 
37 struct cros_ec_hwmon_cooling_priv {
38 	struct cros_ec_hwmon_priv *hwmon_priv;
39 	u8 index;
40 };
41 
42 static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index, u16 *speed)
43 {
44 	int ret;
45 	__le16 __speed;
46 
47 	ret = cros_ec_cmd_readmem(cros_ec, EC_MEMMAP_FAN + index * 2, 2, &__speed);
48 	if (ret < 0)
49 		return ret;
50 
51 	*speed = le16_to_cpu(__speed);
52 	return 0;
53 }
54 
55 static int cros_ec_hwmon_read_pwm_value(struct cros_ec_device *cros_ec, u8 index, u8 *pwm_value)
56 {
57 	struct ec_params_pwm_get_fan_duty req = {
58 		.fan_idx = index,
59 	};
60 	struct ec_response_pwm_get_fan_duty resp;
61 	int ret;
62 
63 	ret = cros_ec_cmd(cros_ec, CROS_EC_HWMON_PWM_GET_FAN_DUTY_CMD_VERSION,
64 			  EC_CMD_PWM_GET_FAN_DUTY, &req, sizeof(req), &resp, sizeof(resp));
65 	if (ret < 0)
66 		return ret;
67 
68 	*pwm_value = (u8)DIV_ROUND_CLOSEST(le32_to_cpu(resp.percent) * 255, 100);
69 	return 0;
70 }
71 
72 static int cros_ec_hwmon_read_pwm_enable(struct cros_ec_device *cros_ec, u8 index,
73 					 u8 *control_method)
74 {
75 	struct ec_params_auto_fan_ctrl_v2 req = {
76 		.cmd = EC_AUTO_FAN_CONTROL_CMD_GET,
77 		.fan_idx = index,
78 	};
79 	struct ec_response_auto_fan_control resp;
80 	int ret;
81 
82 	ret = cros_ec_cmd(cros_ec, CROS_EC_HWMON_THERMAL_AUTO_FAN_CTRL_CMD_VERSION,
83 			  EC_CMD_THERMAL_AUTO_FAN_CTRL, &req, sizeof(req), &resp, sizeof(resp));
84 	if (ret < 0)
85 		return ret;
86 
87 	*control_method = resp.is_auto ? 2 : 1;
88 	return 0;
89 }
90 
91 static int cros_ec_hwmon_read_fan_target(struct cros_ec_device *cros_ec, u16 *speed)
92 {
93 	struct ec_response_pwm_get_fan_rpm resp;
94 	int ret;
95 
96 	ret = cros_ec_cmd(cros_ec, 0, EC_CMD_PWM_GET_FAN_TARGET_RPM,
97 			  NULL, 0, &resp, sizeof(resp));
98 	if (ret < 0)
99 		return ret;
100 
101 	*speed = resp.rpm;
102 	return 0;
103 }
104 
105 static int cros_ec_hwmon_read_temp(struct cros_ec_device *cros_ec, u8 index, u8 *temp)
106 {
107 	unsigned int offset;
108 	int ret;
109 
110 	if (index < EC_TEMP_SENSOR_ENTRIES)
111 		offset = EC_MEMMAP_TEMP_SENSOR + index;
112 	else
113 		offset = EC_MEMMAP_TEMP_SENSOR_B + index - EC_TEMP_SENSOR_ENTRIES;
114 
115 	ret = cros_ec_cmd_readmem(cros_ec, offset, 1, temp);
116 	if (ret < 0)
117 		return ret;
118 	return 0;
119 }
120 
121 static int cros_ec_hwmon_read_temp_threshold(struct cros_ec_device *cros_ec, u8 index,
122 					     enum ec_temp_thresholds threshold, u32 *temp)
123 {
124 	struct ec_params_thermal_get_threshold_v1 req = {};
125 	struct ec_thermal_config resp;
126 	int ret;
127 
128 	req.sensor_num = index;
129 	ret = cros_ec_cmd(cros_ec, 1, EC_CMD_THERMAL_GET_THRESHOLD,
130 			  &req, sizeof(req), &resp, sizeof(resp));
131 	if (ret < 0)
132 		return ret;
133 
134 	*temp = resp.temp_host[threshold];
135 	return 0;
136 }
137 
138 static bool cros_ec_hwmon_is_error_fan(u16 speed)
139 {
140 	return speed == EC_FAN_SPEED_NOT_PRESENT || speed == EC_FAN_SPEED_STALLED;
141 }
142 
143 static bool cros_ec_hwmon_is_error_temp(u8 temp)
144 {
145 	return temp == EC_TEMP_SENSOR_NOT_PRESENT     ||
146 	       temp == EC_TEMP_SENSOR_ERROR           ||
147 	       temp == EC_TEMP_SENSOR_NOT_POWERED     ||
148 	       temp == EC_TEMP_SENSOR_NOT_CALIBRATED;
149 }
150 
151 /* This differs slightly from the variant in units.h to avoid rounding inconsistencies. */
152 #define CROS_EC_HWMON_ABSOLUTE_ZERO_MILLICELSIUS (-273000)
153 
154 static long cros_ec_hwmon_kelvin_to_millicelsius(long t)
155 {
156 	return t * MILLIDEGREE_PER_DEGREE + CROS_EC_HWMON_ABSOLUTE_ZERO_MILLICELSIUS;
157 }
158 
159 static long cros_ec_hwmon_temp_to_millicelsius(u8 temp)
160 {
161 	return cros_ec_hwmon_kelvin_to_millicelsius((((long)temp) + EC_TEMP_SENSOR_OFFSET));
162 }
163 
164 static bool cros_ec_hwmon_attr_is_temp_threshold(u32 attr)
165 {
166 	return attr == hwmon_temp_max ||
167 	       attr == hwmon_temp_crit ||
168 	       attr == hwmon_temp_emergency;
169 }
170 
171 static enum ec_temp_thresholds cros_ec_hwmon_attr_to_thres(u32 attr)
172 {
173 	if (attr == hwmon_temp_max)
174 		return EC_TEMP_THRESH_WARN;
175 	else if (attr == hwmon_temp_crit)
176 		return EC_TEMP_THRESH_HIGH;
177 	return EC_TEMP_THRESH_HALT;	/* attr == hwmon_temp_emergency */
178 }
179 
180 static int cros_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
181 			      u32 attr, int channel, long *val)
182 {
183 	struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev);
184 	int ret = -EOPNOTSUPP;
185 	u8 control_method;
186 	u32 threshold;
187 	u8 pwm_value;
188 	u16 speed;
189 	u8 temp;
190 
191 	if (type == hwmon_fan) {
192 		if (attr == hwmon_fan_input) {
193 			ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, channel, &speed);
194 			if (ret == 0) {
195 				if (cros_ec_hwmon_is_error_fan(speed))
196 					ret = -ENODATA;
197 				else
198 					*val = speed;
199 			}
200 		} else if (attr == hwmon_fan_fault) {
201 			ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, channel, &speed);
202 			if (ret == 0)
203 				*val = cros_ec_hwmon_is_error_fan(speed);
204 
205 		} else if (attr == hwmon_fan_target) {
206 			ret = cros_ec_hwmon_read_fan_target(priv->cros_ec, &speed);
207 			if (ret == 0)
208 				*val = speed;
209 		}
210 	} else if (type == hwmon_pwm) {
211 		if (attr == hwmon_pwm_enable) {
212 			ret = cros_ec_hwmon_read_pwm_enable(priv->cros_ec, channel,
213 							    &control_method);
214 			if (ret == 0)
215 				*val = control_method;
216 		} else if (attr == hwmon_pwm_input) {
217 			ret = cros_ec_hwmon_read_pwm_value(priv->cros_ec, channel, &pwm_value);
218 			if (ret == 0)
219 				*val = pwm_value;
220 		}
221 	} else if (type == hwmon_temp) {
222 		if (attr == hwmon_temp_input) {
223 			ret = cros_ec_hwmon_read_temp(priv->cros_ec, channel, &temp);
224 			if (ret == 0) {
225 				if (cros_ec_hwmon_is_error_temp(temp))
226 					ret = -ENODATA;
227 				else
228 					*val = cros_ec_hwmon_temp_to_millicelsius(temp);
229 			}
230 		} else if (attr == hwmon_temp_fault) {
231 			ret = cros_ec_hwmon_read_temp(priv->cros_ec, channel, &temp);
232 			if (ret == 0)
233 				*val = cros_ec_hwmon_is_error_temp(temp);
234 
235 		} else if (cros_ec_hwmon_attr_is_temp_threshold(attr)) {
236 			ret = cros_ec_hwmon_read_temp_threshold(priv->cros_ec, channel,
237 								cros_ec_hwmon_attr_to_thres(attr),
238 								&threshold);
239 			if (ret == 0) {
240 				/* Limit to sensible, non-overflowing values. */
241 				if (threshold > 255 + 273)
242 					*val = 255000;
243 				else
244 					*val = cros_ec_hwmon_kelvin_to_millicelsius(threshold);
245 			}
246 		}
247 	}
248 
249 	return ret;
250 }
251 
252 static int cros_ec_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
253 				     u32 attr, int channel, const char **str)
254 {
255 	struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev);
256 
257 	if (type == hwmon_temp && attr == hwmon_temp_label) {
258 		*str = priv->temp_sensor_names[channel];
259 		return 0;
260 	}
261 
262 	return -EOPNOTSUPP;
263 }
264 
265 static int cros_ec_hwmon_set_fan_pwm_val(struct cros_ec_device *cros_ec, u8 index, u8 val)
266 {
267 	struct ec_params_pwm_set_fan_duty_v1 req = {
268 		.fan_idx = index,
269 		.percent = DIV_ROUND_CLOSEST((uint32_t)val * 100, 255),
270 	};
271 	int ret;
272 
273 	ret = cros_ec_cmd(cros_ec, CROS_EC_HWMON_PWM_SET_FAN_DUTY_CMD_VERSION,
274 			  EC_CMD_PWM_SET_FAN_DUTY, &req, sizeof(req), NULL, 0);
275 	if (ret < 0)
276 		return ret;
277 	return 0;
278 }
279 
280 static int cros_ec_hwmon_write_pwm_input(struct cros_ec_device *cros_ec, u8 index, u8 val)
281 {
282 	u8 control_method;
283 	int ret;
284 
285 	ret = cros_ec_hwmon_read_pwm_enable(cros_ec, index, &control_method);
286 	if (ret)
287 		return ret;
288 	if (control_method != 1)
289 		return -EOPNOTSUPP;
290 
291 	return cros_ec_hwmon_set_fan_pwm_val(cros_ec, index, val);
292 }
293 
294 static int cros_ec_hwmon_write_pwm_enable(struct cros_ec_device *cros_ec, u8 index, u8 val)
295 {
296 	struct ec_params_auto_fan_ctrl_v2 req = {
297 		.fan_idx = index,
298 		.cmd = EC_AUTO_FAN_CONTROL_CMD_SET,
299 	};
300 	int ret;
301 
302 	/* No CrOS EC supports no fan speed control */
303 	if (val == 0)
304 		return -EOPNOTSUPP;
305 
306 	req.set_auto = (val != 1) ? true : false;
307 	ret = cros_ec_cmd(cros_ec, CROS_EC_HWMON_THERMAL_AUTO_FAN_CTRL_CMD_VERSION,
308 			  EC_CMD_THERMAL_AUTO_FAN_CTRL, &req, sizeof(req), NULL, 0);
309 	if (ret < 0)
310 		return ret;
311 	return 0;
312 }
313 
314 static int cros_ec_hwmon_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
315 			       int channel, long val)
316 {
317 	struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev);
318 
319 	if (type == hwmon_pwm) {
320 		switch (attr) {
321 		case hwmon_pwm_input:
322 			return cros_ec_hwmon_write_pwm_input(priv->cros_ec, channel, val);
323 		case hwmon_pwm_enable:
324 			return cros_ec_hwmon_write_pwm_enable(priv->cros_ec, channel, val);
325 		default:
326 			return -EOPNOTSUPP;
327 		}
328 	}
329 
330 	return -EOPNOTSUPP;
331 }
332 
333 static umode_t cros_ec_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
334 					u32 attr, int channel)
335 {
336 	const struct cros_ec_hwmon_priv *priv = data;
337 	u16 speed;
338 
339 	if (type == hwmon_fan) {
340 		if (attr == hwmon_fan_target &&
341 		    cros_ec_hwmon_read_fan_target(priv->cros_ec, &speed) == -EOPNOTSUPP)
342 			return 0;
343 
344 		if (priv->usable_fans & BIT(channel))
345 			return 0444;
346 	} else if (type == hwmon_pwm) {
347 		if (priv->fan_control_supported && priv->usable_fans & BIT(channel))
348 			return 0644;
349 	} else if (type == hwmon_temp) {
350 		if (priv->temp_sensor_names[channel]) {
351 			if (cros_ec_hwmon_attr_is_temp_threshold(attr)) {
352 				if (priv->temp_threshold_supported)
353 					return 0444;
354 			} else {
355 				return 0444;
356 			}
357 		}
358 	}
359 
360 	return 0;
361 }
362 
363 static const struct hwmon_channel_info * const cros_ec_hwmon_info[] = {
364 	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
365 	HWMON_CHANNEL_INFO(fan,
366 			   HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_TARGET,
367 			   HWMON_F_INPUT | HWMON_F_FAULT,
368 			   HWMON_F_INPUT | HWMON_F_FAULT,
369 			   HWMON_F_INPUT | HWMON_F_FAULT),
370 	HWMON_CHANNEL_INFO(pwm,
371 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
372 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
373 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
374 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
375 #define CROS_EC_HWMON_TEMP_PARAMS (HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL | \
376 				   HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_EMERGENCY)
377 	HWMON_CHANNEL_INFO(temp,
378 			   CROS_EC_HWMON_TEMP_PARAMS,
379 			   CROS_EC_HWMON_TEMP_PARAMS,
380 			   CROS_EC_HWMON_TEMP_PARAMS,
381 			   CROS_EC_HWMON_TEMP_PARAMS,
382 			   CROS_EC_HWMON_TEMP_PARAMS,
383 			   CROS_EC_HWMON_TEMP_PARAMS,
384 			   CROS_EC_HWMON_TEMP_PARAMS,
385 			   CROS_EC_HWMON_TEMP_PARAMS,
386 			   CROS_EC_HWMON_TEMP_PARAMS,
387 			   CROS_EC_HWMON_TEMP_PARAMS,
388 			   CROS_EC_HWMON_TEMP_PARAMS,
389 			   CROS_EC_HWMON_TEMP_PARAMS,
390 			   CROS_EC_HWMON_TEMP_PARAMS,
391 			   CROS_EC_HWMON_TEMP_PARAMS,
392 			   CROS_EC_HWMON_TEMP_PARAMS,
393 			   CROS_EC_HWMON_TEMP_PARAMS,
394 			   CROS_EC_HWMON_TEMP_PARAMS,
395 			   CROS_EC_HWMON_TEMP_PARAMS,
396 			   CROS_EC_HWMON_TEMP_PARAMS,
397 			   CROS_EC_HWMON_TEMP_PARAMS,
398 			   CROS_EC_HWMON_TEMP_PARAMS,
399 			   CROS_EC_HWMON_TEMP_PARAMS,
400 			   CROS_EC_HWMON_TEMP_PARAMS,
401 			   CROS_EC_HWMON_TEMP_PARAMS),
402 	NULL
403 };
404 
405 static int cros_ec_hwmon_cooling_get_max_state(struct thermal_cooling_device *cdev,
406 					       unsigned long *val)
407 {
408 	*val = 255;
409 	return 0;
410 }
411 
412 static int cros_ec_hwmon_cooling_get_cur_state(struct thermal_cooling_device *cdev,
413 					       unsigned long *val)
414 {
415 	const struct cros_ec_hwmon_cooling_priv *priv = cdev->devdata;
416 	u8 read_val;
417 	int ret;
418 
419 	guard(hwmon_lock)(priv->hwmon_priv->hwmon_dev);
420 
421 	ret = cros_ec_hwmon_read_pwm_value(priv->hwmon_priv->cros_ec, priv->index, &read_val);
422 	if (ret)
423 		return ret;
424 
425 	*val = read_val;
426 	return 0;
427 }
428 
429 static int cros_ec_hwmon_cooling_set_cur_state(struct thermal_cooling_device *cdev,
430 					       unsigned long val)
431 {
432 	const struct cros_ec_hwmon_cooling_priv *priv = cdev->devdata;
433 
434 	guard(hwmon_lock)(priv->hwmon_priv->hwmon_dev);
435 
436 	return cros_ec_hwmon_write_pwm_input(priv->hwmon_priv->cros_ec, priv->index, val);
437 }
438 
439 static const struct thermal_cooling_device_ops cros_ec_thermal_cooling_ops = {
440 	.get_max_state = cros_ec_hwmon_cooling_get_max_state,
441 	.get_cur_state = cros_ec_hwmon_cooling_get_cur_state,
442 	.set_cur_state = cros_ec_hwmon_cooling_set_cur_state,
443 };
444 
445 static const struct hwmon_ops cros_ec_hwmon_ops = {
446 	.read = cros_ec_hwmon_read,
447 	.read_string = cros_ec_hwmon_read_string,
448 	.write = cros_ec_hwmon_write,
449 	.is_visible = cros_ec_hwmon_is_visible,
450 };
451 
452 static const struct hwmon_chip_info cros_ec_hwmon_chip_info = {
453 	.ops = &cros_ec_hwmon_ops,
454 	.info = cros_ec_hwmon_info,
455 };
456 
457 static void cros_ec_hwmon_probe_temp_sensors(struct device *dev, struct cros_ec_hwmon_priv *priv,
458 					     u8 thermal_version)
459 {
460 	struct ec_params_temp_sensor_get_info req = {};
461 	struct ec_response_temp_sensor_get_info resp;
462 	size_t candidates, i, sensor_name_size;
463 	int ret;
464 	u8 temp;
465 
466 	if (thermal_version < 2)
467 		candidates = EC_TEMP_SENSOR_ENTRIES;
468 	else
469 		candidates = ARRAY_SIZE(priv->temp_sensor_names);
470 
471 	for (i = 0; i < candidates; i++) {
472 		if (cros_ec_hwmon_read_temp(priv->cros_ec, i, &temp) < 0)
473 			continue;
474 
475 		if (temp == EC_TEMP_SENSOR_NOT_PRESENT)
476 			continue;
477 
478 		req.id = i;
479 		ret = cros_ec_cmd(priv->cros_ec, 0, EC_CMD_TEMP_SENSOR_GET_INFO,
480 				  &req, sizeof(req), &resp, sizeof(resp));
481 		if (ret < 0)
482 			continue;
483 
484 		sensor_name_size = strnlen(resp.sensor_name, sizeof(resp.sensor_name));
485 		priv->temp_sensor_names[i] = devm_kasprintf(dev, GFP_KERNEL, "%.*s",
486 							    (int)sensor_name_size,
487 							    resp.sensor_name);
488 	}
489 }
490 
491 static void cros_ec_hwmon_probe_fans(struct cros_ec_hwmon_priv *priv)
492 {
493 	u16 speed;
494 	size_t i;
495 	int ret;
496 
497 	for (i = 0; i < EC_FAN_SPEED_ENTRIES; i++) {
498 		ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, i, &speed);
499 		if (ret == 0 && speed != EC_FAN_SPEED_NOT_PRESENT)
500 			priv->usable_fans |= BIT(i);
501 	}
502 }
503 
504 static inline bool is_cros_ec_cmd_available(struct cros_ec_device *cros_ec,
505 					    u16 cmd, u8 version)
506 {
507 	int ret;
508 
509 	ret = cros_ec_get_cmd_versions(cros_ec, cmd);
510 	return ret >= 0 && (ret & EC_VER_MASK(version));
511 }
512 
513 static bool cros_ec_hwmon_probe_fan_control_supported(struct cros_ec_device *cros_ec)
514 {
515 	return is_cros_ec_cmd_available(cros_ec, EC_CMD_PWM_GET_FAN_DUTY,
516 					CROS_EC_HWMON_PWM_GET_FAN_DUTY_CMD_VERSION) &&
517 	       is_cros_ec_cmd_available(cros_ec, EC_CMD_PWM_SET_FAN_DUTY,
518 					CROS_EC_HWMON_PWM_SET_FAN_DUTY_CMD_VERSION) &&
519 	       is_cros_ec_cmd_available(cros_ec, EC_CMD_THERMAL_AUTO_FAN_CTRL,
520 					CROS_EC_HWMON_THERMAL_AUTO_FAN_CTRL_CMD_VERSION);
521 }
522 
523 static void cros_ec_hwmon_register_fan_cooling_devices(struct device *dev,
524 						       struct cros_ec_hwmon_priv *priv)
525 {
526 	struct cros_ec_hwmon_cooling_priv *cpriv;
527 	struct thermal_cooling_device *cdev;
528 	const char *type;
529 	size_t i;
530 
531 	if (!IS_ENABLED(CONFIG_THERMAL))
532 		return;
533 
534 	if (!priv->fan_control_supported)
535 		return;
536 
537 	for (i = 0; i < EC_FAN_SPEED_ENTRIES; i++) {
538 		if (!(priv->usable_fans & BIT(i)))
539 			continue;
540 
541 		cpriv = devm_kzalloc(dev, sizeof(*cpriv), GFP_KERNEL);
542 		if (!cpriv)
543 			continue;
544 
545 		type = devm_kasprintf(dev, GFP_KERNEL, "%s-fan%zu", dev_name(dev), i);
546 		if (!type) {
547 			dev_warn(dev, "no memory to compose cooling device type for fan %zu\n", i);
548 			continue;
549 		}
550 
551 		cpriv->hwmon_priv = priv;
552 		cpriv->index = i;
553 		cdev = devm_thermal_cooling_device_register(dev, type, cpriv,
554 							    &cros_ec_thermal_cooling_ops);
555 		if (IS_ERR(cdev)) {
556 			dev_warn(dev, "failed to register fan %zu as a cooling device: %pe\n", i,
557 				 cdev);
558 			continue;
559 		}
560 	}
561 }
562 
563 static int cros_ec_hwmon_probe(struct platform_device *pdev)
564 {
565 	struct device *dev = &pdev->dev;
566 	struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
567 	struct cros_ec_device *cros_ec = ec_dev->ec_dev;
568 	struct cros_ec_hwmon_priv *priv;
569 	u8 thermal_version;
570 	int ret;
571 
572 	ret = cros_ec_cmd_readmem(cros_ec, EC_MEMMAP_THERMAL_VERSION, 1, &thermal_version);
573 	if (ret < 0)
574 		return ret;
575 
576 	/* Covers both fan and temp sensors */
577 	if (thermal_version == 0)
578 		return -ENODEV;
579 
580 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
581 	if (!priv)
582 		return -ENOMEM;
583 
584 	priv->cros_ec = cros_ec;
585 
586 	cros_ec_hwmon_probe_temp_sensors(dev, priv, thermal_version);
587 	cros_ec_hwmon_probe_fans(priv);
588 	priv->fan_control_supported = cros_ec_hwmon_probe_fan_control_supported(priv->cros_ec);
589 	priv->temp_threshold_supported = is_cros_ec_cmd_available(priv->cros_ec,
590 								  EC_CMD_THERMAL_GET_THRESHOLD, 1);
591 
592 	priv->hwmon_dev = devm_hwmon_device_register_with_info(dev, "cros_ec", priv,
593 							       &cros_ec_hwmon_chip_info, NULL);
594 	if (IS_ERR(priv->hwmon_dev))
595 		return PTR_ERR(priv->hwmon_dev);
596 
597 	cros_ec_hwmon_register_fan_cooling_devices(dev, priv);
598 
599 	platform_set_drvdata(pdev, priv);
600 
601 	return 0;
602 }
603 
604 static int cros_ec_hwmon_suspend(struct platform_device *pdev, pm_message_t state)
605 {
606 	struct cros_ec_hwmon_priv *priv = platform_get_drvdata(pdev);
607 	u8 control_method;
608 	size_t i;
609 	int ret;
610 
611 	if (!priv->fan_control_supported)
612 		return 0;
613 
614 	/* EC sets fan control to auto after suspended, store settings before suspending. */
615 	for (i = 0; i < EC_FAN_SPEED_ENTRIES; i++) {
616 		if (!(priv->usable_fans & BIT(i)))
617 			continue;
618 
619 		ret = cros_ec_hwmon_read_pwm_enable(priv->cros_ec, i, &control_method);
620 		if (ret) {
621 			dev_warn(&pdev->dev, "failed to get mode setting for fan %zu: %d\n", i,
622 				 ret);
623 			continue;
624 		}
625 
626 		if (control_method != 1) {
627 			priv->manual_fans &= ~BIT(i);
628 			continue;
629 		} else {
630 			priv->manual_fans |= BIT(i);
631 		}
632 
633 		ret = cros_ec_hwmon_read_pwm_value(priv->cros_ec, i, &priv->manual_fan_pwm[i]);
634 		/*
635 		 * If storing the value failed, invalidate the stored mode value by setting it
636 		 * to auto control. EC will automatically switch to auto mode for that fan after
637 		 * suspended.
638 		 */
639 		if (ret) {
640 			dev_warn(&pdev->dev, "failed to get PWM setting for fan %zu: %pe\n", i,
641 				 ERR_PTR(ret));
642 			priv->manual_fans &= ~BIT(i);
643 			continue;
644 		}
645 	}
646 
647 	return 0;
648 }
649 
650 static int cros_ec_hwmon_resume(struct platform_device *pdev)
651 {
652 	const struct cros_ec_hwmon_priv *priv = platform_get_drvdata(pdev);
653 	size_t i;
654 	int ret;
655 
656 	if (!priv->fan_control_supported)
657 		return 0;
658 
659 	/* EC sets fan control to auto after suspend, restore to settings before suspend. */
660 	for (i = 0; i < EC_FAN_SPEED_ENTRIES; i++) {
661 		if (!(priv->manual_fans & BIT(i)))
662 			continue;
663 
664 		/*
665 		 * Setting fan PWM value to EC will change the mode to manual for that fan in EC as
666 		 * well, so we do not need to issue a separate fan mode to manual call.
667 		 */
668 		ret = cros_ec_hwmon_set_fan_pwm_val(priv->cros_ec, i, priv->manual_fan_pwm[i]);
669 		if (ret)
670 			dev_warn(&pdev->dev, "failed to restore settings for fan %zu: %pe\n", i,
671 				 ERR_PTR(ret));
672 	}
673 
674 	return 0;
675 }
676 
677 static const struct platform_device_id cros_ec_hwmon_id[] = {
678 	{ .name = DRV_NAME },
679 	{ }
680 };
681 MODULE_DEVICE_TABLE(platform, cros_ec_hwmon_id);
682 
683 static struct platform_driver cros_ec_hwmon_driver = {
684 	.driver.name	= DRV_NAME,
685 	.probe		= cros_ec_hwmon_probe,
686 	.suspend	= pm_ptr(cros_ec_hwmon_suspend),
687 	.resume		= pm_ptr(cros_ec_hwmon_resume),
688 	.id_table	= cros_ec_hwmon_id,
689 };
690 module_platform_driver(cros_ec_hwmon_driver);
691 
692 MODULE_DESCRIPTION("ChromeOS EC Hardware Monitoring Driver");
693 MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net");
694 MODULE_LICENSE("GPL");
695