1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <linux/bitfield.h>
4 #include <linux/bits.h>
5 #include <linux/err.h>
6 #include <linux/hwmon.h>
7 #include <linux/hwmon-sysfs.h>
8 #include <linux/i2c.h>
9 #include <linux/regmap.h>
10 #include <linux/util_macros.h>
11 
12 #define REG_CR1		0x00
13 #define CR1_HYST	BIT(5)
14 #define CR1_DRV		GENMASK(4, 3)
15 #define CR1_TEMP_SRC	GENMASK(1, 0)
16 #define REG_CR2		0x01
17 #define CR2_STBY	BIT(7)
18 #define CR2_ALERTS	BIT(6)
19 #define CR2_DFC		BIT(0)
20 #define REG_CR3		0x02
21 #define REG_PWMR	0x50
22 #define REG_PWMV	0x51
23 #define REG_STATUS	0x5A
24 #define STATUS_ALARM_CRIT(ch)	BIT(2 + 2 * (ch))
25 #define STATUS_ALARM_MAX(ch)	BIT(3 + 2 * (ch))
26 #define STATUS_RDFA		BIT(6)
27 
28 #define REG_TACH(ch)		(0x52 + (ch) * 2)
29 #define REG_TEMP_INPUT(ch)	(0x56 + (ch) * 2)
30 #define REG_TEMP_MAX(ch)	(0x06 + (ch) * 2)
31 #define REG_TEMP_CRIT(ch)	(0x0A + (ch) * 2)
32 
33 #define TEMP11_FROM_REG(reg)	((reg) / 32 * 125)
34 #define TEMP11_TO_REG(val)	(DIV_ROUND_CLOSEST(clamp_val((val), -128000, \
35 							     127875), 125) * 32)
36 
37 #define LUT_SIZE	48
38 
39 #define REG_LUT(index)		(0x20 + (index))
40 
41 struct max31760_state {
42 	struct regmap *regmap;
43 
44 	struct lut_attribute {
45 		char name[24];
46 		struct sensor_device_attribute sda;
47 	} lut[LUT_SIZE];
48 
49 	struct attribute *attrs[LUT_SIZE + 2];
50 	struct attribute_group group;
51 	const struct attribute_group *groups[2];
52 };
53 
max31760_volatile_reg(struct device * dev,unsigned int reg)54 static bool max31760_volatile_reg(struct device *dev, unsigned int reg)
55 {
56 	return reg > 0x50;
57 }
58 
59 static const struct regmap_config regmap_config = {
60 	.reg_bits = 8,
61 	.val_bits = 8,
62 	.max_register = 0x5B,
63 	.cache_type = REGCACHE_RBTREE,
64 	.volatile_reg = max31760_volatile_reg,
65 };
66 
67 static const int max31760_pwm_freq[] = {33, 150, 1500, 25000};
68 
tach_to_rpm(u16 tach)69 static int tach_to_rpm(u16 tach)
70 {
71 	if (tach == 0)
72 		tach = 1;
73 
74 	return 60 * 100000 / tach / 2;
75 }
76 
max31760_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)77 static int max31760_read(struct device *dev, enum hwmon_sensor_types type,
78 			 u32 attr, int channel, long *val)
79 {
80 	struct max31760_state *state = dev_get_drvdata(dev);
81 	unsigned int regval;
82 	unsigned int reg_temp;
83 	s16 temp;
84 	u8 reg[2];
85 	int ret;
86 
87 	switch (type) {
88 	case hwmon_temp:
89 		switch (attr) {
90 		case hwmon_temp_fault:
91 			ret = regmap_read(state->regmap, REG_STATUS, &regval);
92 			if (ret)
93 				return ret;
94 
95 			*val = FIELD_GET(STATUS_RDFA, regval);
96 
97 			return 0;
98 		case hwmon_temp_max_alarm:
99 			ret = regmap_read(state->regmap, REG_STATUS, &regval);
100 			if (ret)
101 				return ret;
102 
103 			if (channel)
104 				*val = FIELD_GET(STATUS_ALARM_MAX(1), regval);
105 			else
106 				*val = FIELD_GET(STATUS_ALARM_MAX(0), regval);
107 
108 			return 0;
109 		case hwmon_temp_crit_alarm:
110 			ret = regmap_read(state->regmap, REG_STATUS, &regval);
111 			if (ret)
112 				return ret;
113 
114 			if (channel)
115 				*val = FIELD_GET(STATUS_ALARM_CRIT(1), regval);
116 			else
117 				*val = FIELD_GET(STATUS_ALARM_CRIT(0), regval);
118 
119 			return 0;
120 		case hwmon_temp_input:
121 			reg_temp = REG_TEMP_INPUT(channel);
122 			break;
123 		case hwmon_temp_max:
124 			reg_temp = REG_TEMP_MAX(channel);
125 			break;
126 		case hwmon_temp_crit:
127 			reg_temp = REG_TEMP_CRIT(channel);
128 			break;
129 		default:
130 			return -EOPNOTSUPP;
131 		}
132 
133 		ret = regmap_bulk_read(state->regmap, reg_temp, reg, 2);
134 		if (ret)
135 			return ret;
136 
137 		temp = (reg[0] << 8) | reg[1];
138 
139 		*val = TEMP11_FROM_REG(temp);
140 
141 		return 0;
142 	case hwmon_fan:
143 		switch (attr) {
144 		case hwmon_fan_input:
145 			ret = regmap_bulk_read(state->regmap, REG_TACH(channel), reg, 2);
146 			if (ret)
147 				return ret;
148 
149 			*val = tach_to_rpm(reg[0] * 256 + reg[1]);
150 
151 			return 0;
152 		case hwmon_fan_fault:
153 			ret = regmap_read(state->regmap, REG_STATUS, &regval);
154 			if (ret)
155 				return ret;
156 
157 			if (channel)
158 				*val = FIELD_GET(BIT(1), regval);
159 			else
160 				*val = FIELD_GET(BIT(0), regval);
161 
162 			return 0;
163 		case hwmon_fan_enable:
164 			ret = regmap_read(state->regmap, REG_CR3, &regval);
165 			if (ret)
166 				return ret;
167 
168 			if (channel)
169 				*val = FIELD_GET(BIT(1), regval);
170 			else
171 				*val = FIELD_GET(BIT(0), regval);
172 
173 			return 0;
174 		default:
175 			return -EOPNOTSUPP;
176 		}
177 	case hwmon_pwm:
178 		switch (attr) {
179 		case hwmon_pwm_input:
180 			ret = regmap_read(state->regmap, REG_PWMV, &regval);
181 			if (ret)
182 				return ret;
183 
184 			*val = regval;
185 
186 			return 0;
187 		case hwmon_pwm_freq:
188 			ret = regmap_read(state->regmap, REG_CR1, &regval);
189 			if (ret)
190 				return ret;
191 
192 			regval = FIELD_GET(CR1_DRV, regval);
193 			if (regval >= ARRAY_SIZE(max31760_pwm_freq))
194 				return -EINVAL;
195 
196 			*val = max31760_pwm_freq[regval];
197 
198 			return 0;
199 		case hwmon_pwm_enable:
200 			ret = regmap_read(state->regmap, REG_CR2, &regval);
201 			if (ret)
202 				return ret;
203 
204 			*val = 2 - FIELD_GET(CR2_DFC, regval);
205 
206 			return 0;
207 		case hwmon_pwm_auto_channels_temp:
208 			ret = regmap_read(state->regmap, REG_CR1, &regval);
209 			if (ret)
210 				return ret;
211 
212 			switch (FIELD_GET(CR1_TEMP_SRC, regval)) {
213 			case 0:
214 				*val = 2;
215 				break;
216 			case 1:
217 				*val = 1;
218 				break;
219 			case 2:
220 			case 3:
221 				*val = 3;
222 				break;
223 			default:
224 				return -EINVAL;
225 			}
226 
227 			return 0;
228 		default:
229 			return -EOPNOTSUPP;
230 		}
231 	default:
232 		return -EOPNOTSUPP;
233 	}
234 }
235 
max31760_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)236 static int max31760_write(struct device *dev, enum hwmon_sensor_types type,
237 			  u32 attr, int channel, long val)
238 {
239 	struct max31760_state *state = dev_get_drvdata(dev);
240 	unsigned int pwm_index;
241 	unsigned int reg_temp;
242 	int temp;
243 	u8 reg_val[2];
244 
245 	switch (type) {
246 	case hwmon_temp:
247 		switch (attr) {
248 		case hwmon_temp_max:
249 			reg_temp = REG_TEMP_MAX(channel);
250 			break;
251 		case hwmon_temp_crit:
252 			reg_temp = REG_TEMP_CRIT(channel);
253 			break;
254 		default:
255 			return -EOPNOTSUPP;
256 		}
257 
258 		temp = TEMP11_TO_REG(val);
259 		reg_val[0] = temp >> 8;
260 		reg_val[1] = temp & 0xFF;
261 
262 		return regmap_bulk_write(state->regmap, reg_temp, reg_val, 2);
263 	case hwmon_fan:
264 		switch (attr) {
265 		case hwmon_fan_enable:
266 			if (val == 0)
267 				return regmap_clear_bits(state->regmap, REG_CR3, BIT(channel));
268 
269 			if (val == 1)
270 				return regmap_set_bits(state->regmap, REG_CR3, BIT(channel));
271 
272 			return -EINVAL;
273 		default:
274 			return -EOPNOTSUPP;
275 		}
276 	case hwmon_pwm:
277 		switch (attr) {
278 		case hwmon_pwm_input:
279 			if (val < 0 || val > 255)
280 				return -EINVAL;
281 
282 			return regmap_write(state->regmap, REG_PWMR, val);
283 		case hwmon_pwm_enable:
284 			if (val == 1)
285 				return regmap_set_bits(state->regmap, REG_CR2, CR2_DFC);
286 
287 			if (val == 2)
288 				return regmap_clear_bits(state->regmap, REG_CR2, CR2_DFC);
289 
290 			return -EINVAL;
291 		case hwmon_pwm_freq:
292 			pwm_index = find_closest(val, max31760_pwm_freq,
293 						 ARRAY_SIZE(max31760_pwm_freq));
294 
295 			return regmap_update_bits(state->regmap,
296 						  REG_CR1, CR1_DRV,
297 						  FIELD_PREP(CR1_DRV, pwm_index));
298 		case hwmon_pwm_auto_channels_temp:
299 			switch (val) {
300 			case 1:
301 				break;
302 			case 2:
303 				val = 0;
304 				break;
305 			case 3:
306 				val = 2;
307 				break;
308 			default:
309 				return -EINVAL;
310 			}
311 
312 			return regmap_update_bits(state->regmap, REG_CR1, CR1_TEMP_SRC, val);
313 		default:
314 			return -EOPNOTSUPP;
315 		}
316 	default:
317 		return -EOPNOTSUPP;
318 	}
319 }
320 
321 static const struct hwmon_channel_info *max31760_info[] = {
322 	HWMON_CHANNEL_INFO(chip,
323 			   HWMON_C_REGISTER_TZ),
324 	HWMON_CHANNEL_INFO(fan,
325 			   HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_ENABLE,
326 			   HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_ENABLE),
327 	HWMON_CHANNEL_INFO(temp,
328 			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_FAULT |
329 			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_LABEL,
330 			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
331 			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_LABEL),
332 	HWMON_CHANNEL_INFO(pwm,
333 			   HWMON_PWM_ENABLE | HWMON_PWM_FREQ | HWMON_PWM_INPUT |
334 			   HWMON_PWM_AUTO_CHANNELS_TEMP),
335 	NULL
336 };
337 
max31760_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)338 static umode_t max31760_is_visible(const void *data,
339 				   enum hwmon_sensor_types type,
340 				   u32 attr, int channel)
341 {
342 	switch (type) {
343 	case hwmon_temp:
344 		switch (attr) {
345 		case hwmon_temp_input:
346 		case hwmon_temp_max_alarm:
347 		case hwmon_temp_crit_alarm:
348 		case hwmon_temp_fault:
349 		case hwmon_temp_label:
350 			return 0444;
351 		case hwmon_temp_max:
352 		case hwmon_temp_crit:
353 			return 0644;
354 		default:
355 			return 0;
356 		}
357 	case hwmon_fan:
358 		switch (attr) {
359 		case hwmon_fan_input:
360 		case hwmon_fan_fault:
361 			return 0444;
362 		case hwmon_fan_enable:
363 			return 0644;
364 		default:
365 			return 0;
366 		}
367 	case hwmon_pwm:
368 		switch (attr) {
369 		case hwmon_pwm_enable:
370 		case hwmon_pwm_input:
371 		case hwmon_pwm_freq:
372 		case hwmon_pwm_auto_channels_temp:
373 			return 0644;
374 		default:
375 			return 0;
376 		}
377 	default:
378 		return 0;
379 	}
380 }
381 
max31760_read_string(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,const char ** str)382 static int max31760_read_string(struct device *dev,
383 				enum hwmon_sensor_types type,
384 				u32 attr, int channel, const char **str)
385 {
386 	switch (type) {
387 	case hwmon_temp:
388 		if (attr != hwmon_temp_label)
389 			return -EOPNOTSUPP;
390 
391 		*str = channel ? "local" : "remote";
392 
393 		return 0;
394 	default:
395 		return -EOPNOTSUPP;
396 	}
397 }
398 
399 static const struct hwmon_ops max31760_hwmon_ops = {
400 	.is_visible = max31760_is_visible,
401 	.read = max31760_read,
402 	.write = max31760_write,
403 	.read_string = max31760_read_string
404 };
405 
406 static const struct hwmon_chip_info max31760_chip_info = {
407 	.ops = &max31760_hwmon_ops,
408 	.info = max31760_info,
409 };
410 
lut_show(struct device * dev,struct device_attribute * devattr,char * buf)411 static ssize_t lut_show(struct device *dev,
412 			struct device_attribute *devattr, char *buf)
413 {
414 	struct sensor_device_attribute *sda = to_sensor_dev_attr(devattr);
415 	struct max31760_state *state = dev_get_drvdata(dev);
416 	int ret;
417 	unsigned int regval;
418 
419 	ret = regmap_read(state->regmap, REG_LUT(sda->index), &regval);
420 	if (ret)
421 		return ret;
422 
423 	return sysfs_emit(buf, "%d\n", regval);
424 }
425 
lut_store(struct device * dev,struct device_attribute * devattr,const char * buf,size_t count)426 static ssize_t lut_store(struct device *dev,
427 			 struct device_attribute *devattr,
428 			 const char *buf, size_t count)
429 {
430 	struct sensor_device_attribute *sda = to_sensor_dev_attr(devattr);
431 	struct max31760_state *state = dev_get_drvdata(dev);
432 	int ret;
433 	u8 pwm;
434 
435 	ret = kstrtou8(buf, 10, &pwm);
436 	if (ret)
437 		return ret;
438 
439 	ret = regmap_write(state->regmap, REG_LUT(sda->index), pwm);
440 	if (ret)
441 		return ret;
442 
443 	return count;
444 }
445 
pwm1_auto_point_temp_hyst_show(struct device * dev,struct device_attribute * attr,char * buf)446 static ssize_t pwm1_auto_point_temp_hyst_show(struct device *dev,
447 					      struct device_attribute *attr,
448 					      char *buf)
449 {
450 	struct max31760_state *state = dev_get_drvdata(dev);
451 	unsigned int regval;
452 	int ret;
453 
454 	ret = regmap_read(state->regmap, REG_CR1, &regval);
455 	if (ret)
456 		return ret;
457 
458 	return sysfs_emit(buf, "%d\n", (1 + (int)FIELD_GET(CR1_HYST, regval)) * 2000);
459 }
460 
pwm1_auto_point_temp_hyst_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)461 static ssize_t pwm1_auto_point_temp_hyst_store(struct device *dev,
462 					       struct device_attribute *attr,
463 					       const char *buf,
464 					       size_t count)
465 {
466 	struct max31760_state *state = dev_get_drvdata(dev);
467 	unsigned int hyst;
468 	int ret;
469 
470 	ret = kstrtou32(buf, 10, &hyst);
471 	if (ret)
472 		return ret;
473 
474 	if (hyst < 3000)
475 		ret = regmap_clear_bits(state->regmap, REG_CR1, CR1_HYST);
476 	else
477 		ret = regmap_set_bits(state->regmap, REG_CR1, CR1_HYST);
478 
479 	if (ret)
480 		return ret;
481 
482 	return count;
483 }
484 
485 static DEVICE_ATTR_RW(pwm1_auto_point_temp_hyst);
486 
max31760_create_lut_nodes(struct max31760_state * state)487 static void max31760_create_lut_nodes(struct max31760_state *state)
488 {
489 	int i;
490 	struct sensor_device_attribute *sda;
491 	struct lut_attribute *lut;
492 
493 	for (i = 0; i < LUT_SIZE; ++i) {
494 		lut = &state->lut[i];
495 		sda = &lut->sda;
496 
497 		snprintf(lut->name, sizeof(lut->name),
498 			 "pwm1_auto_point%d_pwm", i + 1);
499 
500 		sda->dev_attr.attr.mode = 0644;
501 		sda->index = i;
502 		sda->dev_attr.show = lut_show;
503 		sda->dev_attr.store = lut_store;
504 		sda->dev_attr.attr.name = lut->name;
505 
506 		sysfs_attr_init(&sda->dev_attr.attr);
507 
508 		state->attrs[i] = &sda->dev_attr.attr;
509 	}
510 
511 	state->attrs[i] = &dev_attr_pwm1_auto_point_temp_hyst.attr;
512 
513 	state->group.attrs = state->attrs;
514 	state->groups[0] = &state->group;
515 }
516 
max31760_probe(struct i2c_client * client)517 static int max31760_probe(struct i2c_client *client)
518 {
519 	struct device *dev = &client->dev;
520 	struct max31760_state *state;
521 	struct device *hwmon_dev;
522 	int ret;
523 
524 	state = devm_kzalloc(dev, sizeof(*state), GFP_KERNEL);
525 	if (!state)
526 		return -ENOMEM;
527 
528 	state->regmap = devm_regmap_init_i2c(client, &regmap_config);
529 	if (IS_ERR(state->regmap))
530 		return dev_err_probe(dev,
531 				     PTR_ERR(state->regmap),
532 				     "regmap initialization failed\n");
533 
534 	dev_set_drvdata(dev, state);
535 
536 	/* Set alert output to comparator mode */
537 	ret = regmap_set_bits(state->regmap, REG_CR2, CR2_ALERTS);
538 	if (ret)
539 		return dev_err_probe(dev, ret, "cannot write register\n");
540 
541 	max31760_create_lut_nodes(state);
542 
543 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
544 							 state,
545 							 &max31760_chip_info,
546 							 state->groups);
547 
548 	return PTR_ERR_OR_ZERO(hwmon_dev);
549 }
550 
551 static const struct of_device_id max31760_of_match[] = {
552 	{.compatible = "adi,max31760"},
553 	{ }
554 };
555 MODULE_DEVICE_TABLE(of, max31760_of_match);
556 
557 static const struct i2c_device_id max31760_id[] = {
558 	{"max31760"},
559 	{ }
560 };
561 MODULE_DEVICE_TABLE(i2c, max31760_id);
562 
max31760_suspend(struct device * dev)563 static int max31760_suspend(struct device *dev)
564 {
565 	struct max31760_state *state = dev_get_drvdata(dev);
566 
567 	return regmap_set_bits(state->regmap, REG_CR2, CR2_STBY);
568 }
569 
max31760_resume(struct device * dev)570 static int max31760_resume(struct device *dev)
571 {
572 	struct max31760_state *state = dev_get_drvdata(dev);
573 
574 	return regmap_clear_bits(state->regmap, REG_CR2, CR2_STBY);
575 }
576 
577 static DEFINE_SIMPLE_DEV_PM_OPS(max31760_pm_ops, max31760_suspend,
578 				max31760_resume);
579 
580 static struct i2c_driver max31760_driver = {
581 	.class		= I2C_CLASS_HWMON,
582 	.driver = {
583 		.name	= "max31760",
584 		.of_match_table = max31760_of_match,
585 		.pm = pm_ptr(&max31760_pm_ops)
586 	},
587 	.probe_new	= max31760_probe,
588 	.id_table	= max31760_id
589 };
590 module_i2c_driver(max31760_driver);
591 
592 MODULE_AUTHOR("Ibrahim Tilki <Ibrahim.Tilki@analog.com>");
593 MODULE_DESCRIPTION("Analog Devices MAX31760 Fan Speed Controller");
594 MODULE_SOFTDEP("pre: regmap_i2c");
595 MODULE_VERSION("1.0");
596 MODULE_LICENSE("GPL");
597