xref: /linux/drivers/hwmon/max31790.c (revision 8c749ce93ee69e789e46b3be98de9e0cbfcf8ed8)
1 /*
2  * max31790.c - Part of lm_sensors, Linux kernel modules for hardware
3  *             monitoring.
4  *
5  * (C) 2015 by Il Han <corone.il.han@gmail.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  */
17 
18 #include <linux/err.h>
19 #include <linux/hwmon.h>
20 #include <linux/hwmon-sysfs.h>
21 #include <linux/i2c.h>
22 #include <linux/init.h>
23 #include <linux/jiffies.h>
24 #include <linux/module.h>
25 #include <linux/slab.h>
26 
27 /* MAX31790 registers */
28 #define MAX31790_REG_GLOBAL_CONFIG	0x00
29 #define MAX31790_REG_FAN_CONFIG(ch)	(0x02 + (ch))
30 #define MAX31790_REG_FAN_DYNAMICS(ch)	(0x08 + (ch))
31 #define MAX31790_REG_FAN_FAULT_STATUS2	0x10
32 #define MAX31790_REG_FAN_FAULT_STATUS1	0x11
33 #define MAX31790_REG_TACH_COUNT(ch)	(0x18 + (ch) * 2)
34 #define MAX31790_REG_PWM_DUTY_CYCLE(ch)	(0x30 + (ch) * 2)
35 #define MAX31790_REG_PWMOUT(ch)		(0x40 + (ch) * 2)
36 #define MAX31790_REG_TARGET_COUNT(ch)	(0x50 + (ch) * 2)
37 
38 /* Fan Config register bits */
39 #define MAX31790_FAN_CFG_RPM_MODE	0x80
40 #define MAX31790_FAN_CFG_TACH_INPUT_EN	0x08
41 #define MAX31790_FAN_CFG_TACH_INPUT	0x01
42 
43 /* Fan Dynamics register bits */
44 #define MAX31790_FAN_DYN_SR_SHIFT	5
45 #define MAX31790_FAN_DYN_SR_MASK	0xE0
46 #define SR_FROM_REG(reg)		(((reg) & MAX31790_FAN_DYN_SR_MASK) \
47 					 >> MAX31790_FAN_DYN_SR_SHIFT)
48 
49 #define FAN_RPM_MIN			120
50 #define FAN_RPM_MAX			7864320
51 
52 #define RPM_FROM_REG(reg, sr)		(((reg) >> 4) ? \
53 					 ((60 * (sr) * 8192) / ((reg) >> 4)) : \
54 					 FAN_RPM_MAX)
55 #define RPM_TO_REG(rpm, sr)		((60 * (sr) * 8192) / ((rpm) * 2))
56 
57 #define NR_CHANNEL			6
58 
59 /*
60  * Client data (each client gets its own)
61  */
62 struct max31790_data {
63 	struct i2c_client *client;
64 	struct mutex update_lock;
65 	bool valid; /* zero until following fields are valid */
66 	unsigned long last_updated; /* in jiffies */
67 
68 	/* register values */
69 	u8 fan_config[NR_CHANNEL];
70 	u8 fan_dynamics[NR_CHANNEL];
71 	u16 fault_status;
72 	u16 tach[NR_CHANNEL * 2];
73 	u16 pwm[NR_CHANNEL];
74 	u16 target_count[NR_CHANNEL];
75 };
76 
77 static struct max31790_data *max31790_update_device(struct device *dev)
78 {
79 	struct max31790_data *data = dev_get_drvdata(dev);
80 	struct i2c_client *client = data->client;
81 	struct max31790_data *ret = data;
82 	int i;
83 	int rv;
84 
85 	mutex_lock(&data->update_lock);
86 
87 	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
88 		rv = i2c_smbus_read_byte_data(client,
89 				MAX31790_REG_FAN_FAULT_STATUS1);
90 		if (rv < 0)
91 			goto abort;
92 		data->fault_status = rv & 0x3F;
93 
94 		rv = i2c_smbus_read_byte_data(client,
95 				MAX31790_REG_FAN_FAULT_STATUS2);
96 		if (rv < 0)
97 			goto abort;
98 		data->fault_status |= (rv & 0x3F) << 6;
99 
100 		for (i = 0; i < NR_CHANNEL; i++) {
101 			rv = i2c_smbus_read_word_swapped(client,
102 					MAX31790_REG_TACH_COUNT(i));
103 			if (rv < 0)
104 				goto abort;
105 			data->tach[i] = rv;
106 
107 			if (data->fan_config[i]
108 			    & MAX31790_FAN_CFG_TACH_INPUT) {
109 				rv = i2c_smbus_read_word_swapped(client,
110 					MAX31790_REG_TACH_COUNT(NR_CHANNEL
111 								+ i));
112 				if (rv < 0)
113 					goto abort;
114 				data->tach[NR_CHANNEL + i] = rv;
115 			} else {
116 				rv = i2c_smbus_read_word_swapped(client,
117 						MAX31790_REG_PWMOUT(i));
118 				if (rv < 0)
119 					goto abort;
120 				data->pwm[i] = rv;
121 
122 				rv = i2c_smbus_read_word_swapped(client,
123 						MAX31790_REG_TARGET_COUNT(i));
124 				if (rv < 0)
125 					goto abort;
126 				data->target_count[i] = rv;
127 			}
128 		}
129 
130 		data->last_updated = jiffies;
131 		data->valid = true;
132 	}
133 	goto done;
134 
135 abort:
136 	data->valid = false;
137 	ret = ERR_PTR(rv);
138 
139 done:
140 	mutex_unlock(&data->update_lock);
141 
142 	return ret;
143 }
144 
145 static const u8 tach_period[8] = { 1, 2, 4, 8, 16, 32, 32, 32 };
146 
147 static u8 get_tach_period(u8 fan_dynamics)
148 {
149 	return tach_period[SR_FROM_REG(fan_dynamics)];
150 }
151 
152 static u8 bits_for_tach_period(int rpm)
153 {
154 	u8 bits;
155 
156 	if (rpm < 500)
157 		bits = 0x0;
158 	else if (rpm < 1000)
159 		bits = 0x1;
160 	else if (rpm < 2000)
161 		bits = 0x2;
162 	else if (rpm < 4000)
163 		bits = 0x3;
164 	else if (rpm < 8000)
165 		bits = 0x4;
166 	else
167 		bits = 0x5;
168 
169 	return bits;
170 }
171 
172 static ssize_t get_fan(struct device *dev,
173 		       struct device_attribute *devattr, char *buf)
174 {
175 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
176 	struct max31790_data *data = max31790_update_device(dev);
177 	int sr, rpm;
178 
179 	if (IS_ERR(data))
180 		return PTR_ERR(data);
181 
182 	sr = get_tach_period(data->fan_dynamics[attr->index]);
183 	rpm = RPM_FROM_REG(data->tach[attr->index], sr);
184 
185 	return sprintf(buf, "%d\n", rpm);
186 }
187 
188 static ssize_t get_fan_target(struct device *dev,
189 			      struct device_attribute *devattr, char *buf)
190 {
191 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
192 	struct max31790_data *data = max31790_update_device(dev);
193 	int sr, rpm;
194 
195 	if (IS_ERR(data))
196 		return PTR_ERR(data);
197 
198 	sr = get_tach_period(data->fan_dynamics[attr->index]);
199 	rpm = RPM_FROM_REG(data->target_count[attr->index], sr);
200 
201 	return sprintf(buf, "%d\n", rpm);
202 }
203 
204 static ssize_t set_fan_target(struct device *dev,
205 			      struct device_attribute *devattr,
206 			      const char *buf, size_t count)
207 {
208 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
209 	struct max31790_data *data = dev_get_drvdata(dev);
210 	struct i2c_client *client = data->client;
211 	u8 bits;
212 	int sr;
213 	int target_count;
214 	unsigned long rpm;
215 	int err;
216 
217 	err = kstrtoul(buf, 10, &rpm);
218 	if (err)
219 		return err;
220 
221 	mutex_lock(&data->update_lock);
222 
223 	rpm = clamp_val(rpm, FAN_RPM_MIN, FAN_RPM_MAX);
224 	bits = bits_for_tach_period(rpm);
225 	data->fan_dynamics[attr->index] =
226 			((data->fan_dynamics[attr->index]
227 			  & ~MAX31790_FAN_DYN_SR_MASK)
228 			 | (bits << MAX31790_FAN_DYN_SR_SHIFT));
229 	err = i2c_smbus_write_byte_data(client,
230 			MAX31790_REG_FAN_DYNAMICS(attr->index),
231 			data->fan_dynamics[attr->index]);
232 
233 	if (err < 0) {
234 		mutex_unlock(&data->update_lock);
235 		return err;
236 	}
237 
238 	sr = get_tach_period(data->fan_dynamics[attr->index]);
239 	target_count = RPM_TO_REG(rpm, sr);
240 	target_count = clamp_val(target_count, 0x1, 0x7FF);
241 
242 	data->target_count[attr->index] = target_count << 5;
243 
244 	err = i2c_smbus_write_word_swapped(client,
245 			MAX31790_REG_TARGET_COUNT(attr->index),
246 			data->target_count[attr->index]);
247 
248 	mutex_unlock(&data->update_lock);
249 
250 	if (err < 0)
251 		return err;
252 
253 	return count;
254 }
255 
256 static ssize_t get_pwm(struct device *dev,
257 		       struct device_attribute *devattr, char *buf)
258 {
259 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
260 	struct max31790_data *data = max31790_update_device(dev);
261 	int pwm;
262 
263 	if (IS_ERR(data))
264 		return PTR_ERR(data);
265 
266 	pwm = data->pwm[attr->index] >> 8;
267 
268 	return sprintf(buf, "%d\n", pwm);
269 }
270 
271 static ssize_t set_pwm(struct device *dev,
272 		       struct device_attribute *devattr,
273 		       const char *buf, size_t count)
274 {
275 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
276 	struct max31790_data *data = dev_get_drvdata(dev);
277 	struct i2c_client *client = data->client;
278 	unsigned long pwm;
279 	int err;
280 
281 	err = kstrtoul(buf, 10, &pwm);
282 	if (err)
283 		return err;
284 
285 	if (pwm > 255)
286 		return -EINVAL;
287 
288 	mutex_lock(&data->update_lock);
289 
290 	data->pwm[attr->index] = pwm << 8;
291 	err = i2c_smbus_write_word_swapped(client,
292 			MAX31790_REG_PWMOUT(attr->index),
293 			data->pwm[attr->index]);
294 
295 	mutex_unlock(&data->update_lock);
296 
297 	if (err < 0)
298 		return err;
299 
300 	return count;
301 }
302 
303 static ssize_t get_pwm_enable(struct device *dev,
304 			      struct device_attribute *devattr, char *buf)
305 {
306 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
307 	struct max31790_data *data = max31790_update_device(dev);
308 	int mode;
309 
310 	if (IS_ERR(data))
311 		return PTR_ERR(data);
312 
313 	if (data->fan_config[attr->index] & MAX31790_FAN_CFG_RPM_MODE)
314 		mode = 2;
315 	else if (data->fan_config[attr->index] & MAX31790_FAN_CFG_TACH_INPUT_EN)
316 		mode = 1;
317 	else
318 		mode = 0;
319 
320 	return sprintf(buf, "%d\n", mode);
321 }
322 
323 static ssize_t set_pwm_enable(struct device *dev,
324 			      struct device_attribute *devattr,
325 			      const char *buf, size_t count)
326 {
327 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
328 	struct max31790_data *data = dev_get_drvdata(dev);
329 	struct i2c_client *client = data->client;
330 	unsigned long mode;
331 	int err;
332 
333 	err = kstrtoul(buf, 10, &mode);
334 	if (err)
335 		return err;
336 
337 	switch (mode) {
338 	case 0:
339 		data->fan_config[attr->index] =
340 			data->fan_config[attr->index]
341 			& ~(MAX31790_FAN_CFG_TACH_INPUT_EN
342 			    | MAX31790_FAN_CFG_RPM_MODE);
343 		break;
344 	case 1:
345 		data->fan_config[attr->index] =
346 			(data->fan_config[attr->index]
347 			 | MAX31790_FAN_CFG_TACH_INPUT_EN)
348 			& ~MAX31790_FAN_CFG_RPM_MODE;
349 		break;
350 	case 2:
351 		data->fan_config[attr->index] =
352 			data->fan_config[attr->index]
353 			| MAX31790_FAN_CFG_TACH_INPUT_EN
354 			| MAX31790_FAN_CFG_RPM_MODE;
355 		break;
356 	default:
357 		return -EINVAL;
358 	}
359 
360 	mutex_lock(&data->update_lock);
361 
362 	err = i2c_smbus_write_byte_data(client,
363 			MAX31790_REG_FAN_CONFIG(attr->index),
364 			data->fan_config[attr->index]);
365 
366 	mutex_unlock(&data->update_lock);
367 
368 	if (err < 0)
369 		return err;
370 
371 	return count;
372 }
373 
374 static ssize_t get_fan_fault(struct device *dev,
375 			     struct device_attribute *devattr, char *buf)
376 {
377 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
378 	struct max31790_data *data = max31790_update_device(dev);
379 	int fault;
380 
381 	if (IS_ERR(data))
382 		return PTR_ERR(data);
383 
384 	fault = !!(data->fault_status & (1 << attr->index));
385 
386 	return sprintf(buf, "%d\n", fault);
387 }
388 
389 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, 0);
390 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, get_fan, NULL, 1);
391 static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, get_fan, NULL, 2);
392 static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, get_fan, NULL, 3);
393 static SENSOR_DEVICE_ATTR(fan5_input, S_IRUGO, get_fan, NULL, 4);
394 static SENSOR_DEVICE_ATTR(fan6_input, S_IRUGO, get_fan, NULL, 5);
395 
396 static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, get_fan_fault, NULL, 0);
397 static SENSOR_DEVICE_ATTR(fan2_fault, S_IRUGO, get_fan_fault, NULL, 1);
398 static SENSOR_DEVICE_ATTR(fan3_fault, S_IRUGO, get_fan_fault, NULL, 2);
399 static SENSOR_DEVICE_ATTR(fan4_fault, S_IRUGO, get_fan_fault, NULL, 3);
400 static SENSOR_DEVICE_ATTR(fan5_fault, S_IRUGO, get_fan_fault, NULL, 4);
401 static SENSOR_DEVICE_ATTR(fan6_fault, S_IRUGO, get_fan_fault, NULL, 5);
402 
403 static SENSOR_DEVICE_ATTR(fan7_input, S_IRUGO, get_fan, NULL, 6);
404 static SENSOR_DEVICE_ATTR(fan8_input, S_IRUGO, get_fan, NULL, 7);
405 static SENSOR_DEVICE_ATTR(fan9_input, S_IRUGO, get_fan, NULL, 8);
406 static SENSOR_DEVICE_ATTR(fan10_input, S_IRUGO, get_fan, NULL, 9);
407 static SENSOR_DEVICE_ATTR(fan11_input, S_IRUGO, get_fan, NULL, 10);
408 static SENSOR_DEVICE_ATTR(fan12_input, S_IRUGO, get_fan, NULL, 11);
409 
410 static SENSOR_DEVICE_ATTR(fan7_fault, S_IRUGO, get_fan_fault, NULL, 6);
411 static SENSOR_DEVICE_ATTR(fan8_fault, S_IRUGO, get_fan_fault, NULL, 7);
412 static SENSOR_DEVICE_ATTR(fan9_fault, S_IRUGO, get_fan_fault, NULL, 8);
413 static SENSOR_DEVICE_ATTR(fan10_fault, S_IRUGO, get_fan_fault, NULL, 9);
414 static SENSOR_DEVICE_ATTR(fan11_fault, S_IRUGO, get_fan_fault, NULL, 10);
415 static SENSOR_DEVICE_ATTR(fan12_fault, S_IRUGO, get_fan_fault, NULL, 11);
416 
417 static SENSOR_DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO,
418 		get_fan_target, set_fan_target, 0);
419 static SENSOR_DEVICE_ATTR(fan2_target, S_IWUSR | S_IRUGO,
420 		get_fan_target, set_fan_target, 1);
421 static SENSOR_DEVICE_ATTR(fan3_target, S_IWUSR | S_IRUGO,
422 		get_fan_target, set_fan_target, 2);
423 static SENSOR_DEVICE_ATTR(fan4_target, S_IWUSR | S_IRUGO,
424 		get_fan_target, set_fan_target, 3);
425 static SENSOR_DEVICE_ATTR(fan5_target, S_IWUSR | S_IRUGO,
426 		get_fan_target, set_fan_target, 4);
427 static SENSOR_DEVICE_ATTR(fan6_target, S_IWUSR | S_IRUGO,
428 		get_fan_target, set_fan_target, 5);
429 
430 static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 0);
431 static SENSOR_DEVICE_ATTR(pwm2, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 1);
432 static SENSOR_DEVICE_ATTR(pwm3, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 2);
433 static SENSOR_DEVICE_ATTR(pwm4, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 3);
434 static SENSOR_DEVICE_ATTR(pwm5, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 4);
435 static SENSOR_DEVICE_ATTR(pwm6, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 5);
436 
437 static SENSOR_DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO,
438 		get_pwm_enable, set_pwm_enable, 0);
439 static SENSOR_DEVICE_ATTR(pwm2_enable, S_IWUSR | S_IRUGO,
440 		get_pwm_enable, set_pwm_enable, 1);
441 static SENSOR_DEVICE_ATTR(pwm3_enable, S_IWUSR | S_IRUGO,
442 		get_pwm_enable, set_pwm_enable, 2);
443 static SENSOR_DEVICE_ATTR(pwm4_enable, S_IWUSR | S_IRUGO,
444 		get_pwm_enable, set_pwm_enable, 3);
445 static SENSOR_DEVICE_ATTR(pwm5_enable, S_IWUSR | S_IRUGO,
446 		get_pwm_enable, set_pwm_enable, 4);
447 static SENSOR_DEVICE_ATTR(pwm6_enable, S_IWUSR | S_IRUGO,
448 		get_pwm_enable, set_pwm_enable, 5);
449 
450 static struct attribute *max31790_attrs[] = {
451 	&sensor_dev_attr_fan1_input.dev_attr.attr,
452 	&sensor_dev_attr_fan2_input.dev_attr.attr,
453 	&sensor_dev_attr_fan3_input.dev_attr.attr,
454 	&sensor_dev_attr_fan4_input.dev_attr.attr,
455 	&sensor_dev_attr_fan5_input.dev_attr.attr,
456 	&sensor_dev_attr_fan6_input.dev_attr.attr,
457 
458 	&sensor_dev_attr_fan1_fault.dev_attr.attr,
459 	&sensor_dev_attr_fan2_fault.dev_attr.attr,
460 	&sensor_dev_attr_fan3_fault.dev_attr.attr,
461 	&sensor_dev_attr_fan4_fault.dev_attr.attr,
462 	&sensor_dev_attr_fan5_fault.dev_attr.attr,
463 	&sensor_dev_attr_fan6_fault.dev_attr.attr,
464 
465 	&sensor_dev_attr_fan7_input.dev_attr.attr,
466 	&sensor_dev_attr_fan8_input.dev_attr.attr,
467 	&sensor_dev_attr_fan9_input.dev_attr.attr,
468 	&sensor_dev_attr_fan10_input.dev_attr.attr,
469 	&sensor_dev_attr_fan11_input.dev_attr.attr,
470 	&sensor_dev_attr_fan12_input.dev_attr.attr,
471 
472 	&sensor_dev_attr_fan7_fault.dev_attr.attr,
473 	&sensor_dev_attr_fan8_fault.dev_attr.attr,
474 	&sensor_dev_attr_fan9_fault.dev_attr.attr,
475 	&sensor_dev_attr_fan10_fault.dev_attr.attr,
476 	&sensor_dev_attr_fan11_fault.dev_attr.attr,
477 	&sensor_dev_attr_fan12_fault.dev_attr.attr,
478 
479 	&sensor_dev_attr_fan1_target.dev_attr.attr,
480 	&sensor_dev_attr_fan2_target.dev_attr.attr,
481 	&sensor_dev_attr_fan3_target.dev_attr.attr,
482 	&sensor_dev_attr_fan4_target.dev_attr.attr,
483 	&sensor_dev_attr_fan5_target.dev_attr.attr,
484 	&sensor_dev_attr_fan6_target.dev_attr.attr,
485 
486 	&sensor_dev_attr_pwm1.dev_attr.attr,
487 	&sensor_dev_attr_pwm2.dev_attr.attr,
488 	&sensor_dev_attr_pwm3.dev_attr.attr,
489 	&sensor_dev_attr_pwm4.dev_attr.attr,
490 	&sensor_dev_attr_pwm5.dev_attr.attr,
491 	&sensor_dev_attr_pwm6.dev_attr.attr,
492 
493 	&sensor_dev_attr_pwm1_enable.dev_attr.attr,
494 	&sensor_dev_attr_pwm2_enable.dev_attr.attr,
495 	&sensor_dev_attr_pwm3_enable.dev_attr.attr,
496 	&sensor_dev_attr_pwm4_enable.dev_attr.attr,
497 	&sensor_dev_attr_pwm5_enable.dev_attr.attr,
498 	&sensor_dev_attr_pwm6_enable.dev_attr.attr,
499 	NULL
500 };
501 
502 static umode_t max31790_attrs_visible(struct kobject *kobj,
503 				     struct attribute *a, int n)
504 {
505 	struct device *dev = container_of(kobj, struct device, kobj);
506 	struct max31790_data *data = dev_get_drvdata(dev);
507 	struct device_attribute *devattr =
508 			container_of(a, struct device_attribute, attr);
509 	int index = to_sensor_dev_attr(devattr)->index % NR_CHANNEL;
510 	u8 fan_config;
511 
512 	fan_config = data->fan_config[index];
513 
514 	if (n >= NR_CHANNEL * 2 && n < NR_CHANNEL * 4 &&
515 	    !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
516 		return 0;
517 	if (n >= NR_CHANNEL * 4 && (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
518 		return 0;
519 
520 	return a->mode;
521 }
522 
523 static const struct attribute_group max31790_group = {
524 	.attrs = max31790_attrs,
525 	.is_visible = max31790_attrs_visible,
526 };
527 __ATTRIBUTE_GROUPS(max31790);
528 
529 static int max31790_init_client(struct i2c_client *client,
530 				struct max31790_data *data)
531 {
532 	int i, rv;
533 
534 	for (i = 0; i < NR_CHANNEL; i++) {
535 		rv = i2c_smbus_read_byte_data(client,
536 				MAX31790_REG_FAN_CONFIG(i));
537 		if (rv < 0)
538 			return rv;
539 		data->fan_config[i] = rv;
540 
541 		rv = i2c_smbus_read_byte_data(client,
542 				MAX31790_REG_FAN_DYNAMICS(i));
543 		if (rv < 0)
544 			return rv;
545 		data->fan_dynamics[i] = rv;
546 	}
547 
548 	return 0;
549 }
550 
551 static int max31790_probe(struct i2c_client *client,
552 			  const struct i2c_device_id *id)
553 {
554 	struct i2c_adapter *adapter = client->adapter;
555 	struct device *dev = &client->dev;
556 	struct max31790_data *data;
557 	struct device *hwmon_dev;
558 	int err;
559 
560 	if (!i2c_check_functionality(adapter,
561 			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
562 		return -ENODEV;
563 
564 	data = devm_kzalloc(dev, sizeof(struct max31790_data), GFP_KERNEL);
565 	if (!data)
566 		return -ENOMEM;
567 
568 	data->client = client;
569 	mutex_init(&data->update_lock);
570 
571 	/*
572 	 * Initialize the max31790 chip
573 	 */
574 	err = max31790_init_client(client, data);
575 	if (err)
576 		return err;
577 
578 	hwmon_dev = devm_hwmon_device_register_with_groups(dev,
579 			client->name, data, max31790_groups);
580 
581 	return PTR_ERR_OR_ZERO(hwmon_dev);
582 }
583 
584 static const struct i2c_device_id max31790_id[] = {
585 	{ "max31790", 0 },
586 	{ }
587 };
588 MODULE_DEVICE_TABLE(i2c, max31790_id);
589 
590 static struct i2c_driver max31790_driver = {
591 	.class		= I2C_CLASS_HWMON,
592 	.probe		= max31790_probe,
593 	.driver = {
594 		.name	= "max31790",
595 	},
596 	.id_table	= max31790_id,
597 };
598 
599 module_i2c_driver(max31790_driver);
600 
601 MODULE_AUTHOR("Il Han <corone.il.han@gmail.com>");
602 MODULE_DESCRIPTION("MAX31790 sensor driver");
603 MODULE_LICENSE("GPL");
604