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