xref: /linux/drivers/hwmon/emc2305.c (revision b4ada0618eed0fbd1b1630f73deb048c592b06a1)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Hardware monitoring driver for EMC2305 fan controller
4  *
5  * Copyright (C) 2022 Nvidia Technologies Ltd.
6  */
7 
8 #include <linux/err.h>
9 #include <linux/hwmon.h>
10 #include <linux/i2c.h>
11 #include <linux/module.h>
12 #include <linux/platform_data/emc2305.h>
13 #include <linux/thermal.h>
14 #include <linux/pwm.h>
15 #include <linux/of_device.h>
16 #include <linux/util_macros.h>
17 
18 #define EMC2305_REG_DRIVE_FAIL_STATUS	0x27
19 #define EMC2305_REG_VENDOR		0xfe
20 #define EMC2305_FAN_MAX			0xff
21 #define EMC2305_FAN_MIN			0x00
22 #define EMC2305_FAN_MAX_STATE		10
23 #define EMC2305_DEVICE			0x34
24 #define EMC2305_VENDOR			0x5d
25 #define EMC2305_REG_PRODUCT_ID		0xfd
26 #define EMC2305_TACH_REGS_UNUSE_BITS	3
27 #define EMC2305_TACH_CNT_MULTIPLIER	0x02
28 #define EMC2305_TACH_RANGE_MIN		480
29 #define EMC2305_DEFAULT_OUTPUT		0x0
30 #define EMC2305_DEFAULT_POLARITY	0x0
31 #define EMC2305_REG_POLARITY		0x2a
32 #define EMC2305_REG_DRIVE_PWM_OUT	0x2b
33 #define EMC2305_OPEN_DRAIN		0x0
34 #define EMC2305_PUSH_PULL		0x1
35 
36 #define EMC2305_PWM_DUTY2STATE(duty, max_state, pwm_max) \
37 	DIV_ROUND_CLOSEST((duty) * (max_state), (pwm_max))
38 #define EMC2305_PWM_STATE2DUTY(state, max_state, pwm_max) \
39 	DIV_ROUND_CLOSEST((state) * (pwm_max), (max_state))
40 
41 /*
42  * Factor by equations [2] and [3] from data sheet; valid for fans where the number of edges
43  * equal (poles * 2 + 1).
44  */
45 #define EMC2305_RPM_FACTOR		3932160
46 
47 #define EMC2305_REG_FAN_DRIVE(n)	(0x30 + 0x10 * (n))
48 #define EMC2305_REG_FAN_MIN_DRIVE(n)	(0x38 + 0x10 * (n))
49 #define EMC2305_REG_FAN_TACH(n)		(0x3e + 0x10 * (n))
50 
51 /* Supported base PWM frequencies */
52 static const unsigned int base_freq_table[] = { 2441, 4882, 19530, 26000 };
53 
54 enum emc230x_product_id {
55 	EMC2305 = 0x34,
56 	EMC2303 = 0x35,
57 	EMC2302 = 0x36,
58 	EMC2301 = 0x37,
59 };
60 
61 static const struct i2c_device_id emc2305_ids[] = {
62 	{ "emc2305" },
63 	{ "emc2303" },
64 	{ "emc2302" },
65 	{ "emc2301" },
66 	{ }
67 };
68 MODULE_DEVICE_TABLE(i2c, emc2305_ids);
69 
70 /**
71  * struct emc2305_cdev_data - device-specific cooling device state
72  * @cdev: cooling device
73  * @cur_state: cooling current state
74  * @last_hwmon_state: last cooling state updated by hwmon subsystem
75  * @last_thermal_state: last cooling state updated by thermal subsystem
76  *
77  * The 'last_hwmon_state' and 'last_thermal_state' fields are provided to support fan low limit
78  * speed feature. The purpose of this feature is to provides ability to limit fan speed
79  * according to some system wise considerations, like absence of some replaceable units (PSU or
80  * line cards), high system ambient temperature, unreliable transceivers temperature sensing or
81  * some other factors which indirectly impacts system's airflow
82  * Fan low limit feature is supported through 'hwmon' interface: 'hwmon' 'pwm' attribute is
83  * used for setting low limit for fan speed in case 'thermal' subsystem is configured in
84  * kernel. In this case setting fan speed through 'hwmon' will never let the 'thermal'
85  * subsystem to select a lower duty cycle than the duty cycle selected with the 'pwm'
86  * attribute.
87  * From other side, fan speed is to be updated in hardware through 'pwm' only in case the
88  * requested fan speed is above last speed set by 'thermal' subsystem, otherwise requested fan
89  * speed will be just stored with no PWM update.
90  */
91 struct emc2305_cdev_data {
92 	struct thermal_cooling_device *cdev;
93 	unsigned int cur_state;
94 	unsigned long last_hwmon_state;
95 	unsigned long last_thermal_state;
96 };
97 
98 /**
99  * struct emc2305_data - device-specific data
100  * @client: i2c client
101  * @hwmon_dev: hwmon device
102  * @max_state: maximum cooling state of the cooling device
103  * @pwm_num: number of PWM channels
104  * @pwm_output_mask: PWM output mask
105  * @pwm_polarity_mask: PWM polarity mask
106  * @pwm_separate: separate PWM settings for every channel
107  * @pwm_min: array of minimum PWM per channel
108  * @pwm_freq: array of PWM frequency per channel
109  * @cdev_data: array of cooling devices data
110  */
111 struct emc2305_data {
112 	struct i2c_client *client;
113 	struct device *hwmon_dev;
114 	u8 max_state;
115 	u8 pwm_num;
116 	u8 pwm_output_mask;
117 	u8 pwm_polarity_mask;
118 	bool pwm_separate;
119 	u8 pwm_min[EMC2305_PWM_MAX];
120 	u16 pwm_freq[EMC2305_PWM_MAX];
121 	struct emc2305_cdev_data cdev_data[EMC2305_PWM_MAX];
122 };
123 
124 static char *emc2305_fan_name[] = {
125 	"emc2305_fan",
126 	"emc2305_fan1",
127 	"emc2305_fan2",
128 	"emc2305_fan3",
129 	"emc2305_fan4",
130 	"emc2305_fan5",
131 };
132 
133 static int emc2305_get_max_channel(const struct emc2305_data *data)
134 {
135 	return data->pwm_num;
136 }
137 
138 static int emc2305_get_cdev_idx(struct thermal_cooling_device *cdev)
139 {
140 	struct emc2305_data *data = cdev->devdata;
141 	size_t len = strlen(cdev->type);
142 	int ret;
143 
144 	if (len <= 0)
145 		return -EINVAL;
146 
147 	/*
148 	 * Returns index of cooling device 0..4 in case of separate PWM setting.
149 	 * Zero index is used in case of one common PWM setting.
150 	 * If the mode is not set as pwm_separate, all PWMs are to be bound
151 	 * to the common thermal zone and should work at the same speed
152 	 * to perform cooling for the same thermal junction.
153 	 * Otherwise, return specific channel that will be used in bound
154 	 * related PWM to the thermal zone.
155 	 */
156 	if (!data->pwm_separate)
157 		return 0;
158 
159 	ret = cdev->type[len - 1];
160 	switch (ret) {
161 	case '1' ... '5':
162 		return ret - '1';
163 	default:
164 		break;
165 	}
166 	return -EINVAL;
167 }
168 
169 static int emc2305_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state)
170 {
171 	int cdev_idx;
172 	struct emc2305_data *data = cdev->devdata;
173 
174 	cdev_idx = emc2305_get_cdev_idx(cdev);
175 	if (cdev_idx < 0)
176 		return cdev_idx;
177 
178 	*state = data->cdev_data[cdev_idx].cur_state;
179 	return 0;
180 }
181 
182 static int emc2305_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state)
183 {
184 	struct emc2305_data *data = cdev->devdata;
185 	*state = data->max_state;
186 	return 0;
187 }
188 
189 static int __emc2305_set_cur_state(struct emc2305_data *data, int cdev_idx, unsigned long state)
190 {
191 	int ret;
192 	struct i2c_client *client = data->client;
193 	u8 val, i;
194 
195 	state = max_t(unsigned long, state, data->cdev_data[cdev_idx].last_hwmon_state);
196 
197 	val = EMC2305_PWM_STATE2DUTY(state, data->max_state, EMC2305_FAN_MAX);
198 
199 	data->cdev_data[cdev_idx].cur_state = state;
200 	if (data->pwm_separate) {
201 		ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(cdev_idx), val);
202 		if (ret < 0)
203 			return ret;
204 	} else {
205 		/*
206 		 * Set the same PWM value in all channels
207 		 * if common PWM channel is used.
208 		 */
209 		for (i = 0; i < data->pwm_num; i++) {
210 			ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(i), val);
211 			if (ret < 0)
212 				return ret;
213 		}
214 	}
215 
216 	return 0;
217 }
218 
219 static int emc2305_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
220 {
221 	int cdev_idx, ret;
222 	struct emc2305_data *data = cdev->devdata;
223 
224 	if (state > data->max_state)
225 		return -EINVAL;
226 
227 	cdev_idx =  emc2305_get_cdev_idx(cdev);
228 	if (cdev_idx < 0)
229 		return cdev_idx;
230 
231 	/* Save thermal state. */
232 	data->cdev_data[cdev_idx].last_thermal_state = state;
233 	ret = __emc2305_set_cur_state(data, cdev_idx, state);
234 	if (ret < 0)
235 		return ret;
236 
237 	return 0;
238 }
239 
240 static const struct thermal_cooling_device_ops emc2305_cooling_ops = {
241 	.get_max_state = emc2305_get_max_state,
242 	.get_cur_state = emc2305_get_cur_state,
243 	.set_cur_state = emc2305_set_cur_state,
244 };
245 
246 static int emc2305_show_fault(struct device *dev, int channel)
247 {
248 	struct emc2305_data *data = dev_get_drvdata(dev);
249 	struct i2c_client *client = data->client;
250 	int status_reg;
251 
252 	status_reg = i2c_smbus_read_byte_data(client, EMC2305_REG_DRIVE_FAIL_STATUS);
253 	if (status_reg < 0)
254 		return status_reg;
255 
256 	return status_reg & (1 << channel) ? 1 : 0;
257 }
258 
259 static int emc2305_show_fan(struct device *dev, int channel)
260 {
261 	struct emc2305_data *data = dev_get_drvdata(dev);
262 	struct i2c_client *client = data->client;
263 	int ret;
264 
265 	ret = i2c_smbus_read_word_swapped(client, EMC2305_REG_FAN_TACH(channel));
266 	if (ret <= 0)
267 		return ret;
268 
269 	ret = ret >> EMC2305_TACH_REGS_UNUSE_BITS;
270 	ret = EMC2305_RPM_FACTOR / ret;
271 	if (ret <= EMC2305_TACH_RANGE_MIN)
272 		return 0;
273 
274 	return ret * EMC2305_TACH_CNT_MULTIPLIER;
275 }
276 
277 static int emc2305_show_pwm(struct device *dev, int channel)
278 {
279 	struct emc2305_data *data = dev_get_drvdata(dev);
280 	struct i2c_client *client = data->client;
281 
282 	return i2c_smbus_read_byte_data(client, EMC2305_REG_FAN_DRIVE(channel));
283 }
284 
285 static int emc2305_set_pwm(struct device *dev, long val, int channel)
286 {
287 	struct emc2305_data *data = dev_get_drvdata(dev);
288 	struct i2c_client *client = data->client;
289 	int ret;
290 
291 	if (val < data->pwm_min[channel] || val > EMC2305_FAN_MAX)
292 		return -EINVAL;
293 
294 	ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(channel), val);
295 	if (ret < 0)
296 		return ret;
297 	data->cdev_data[channel].cur_state = EMC2305_PWM_DUTY2STATE(val, data->max_state,
298 								    EMC2305_FAN_MAX);
299 	return 0;
300 }
301 
302 static int emc2305_set_single_tz(struct device *dev, struct device_node *fan_node, int idx)
303 {
304 	struct emc2305_data *data = dev_get_drvdata(dev);
305 	long pwm;
306 	int i, cdev_idx, ret;
307 
308 	cdev_idx = (idx) ? idx - 1 : 0;
309 	pwm = data->pwm_min[cdev_idx];
310 
311 	data->cdev_data[cdev_idx].cdev =
312 		devm_thermal_of_cooling_device_register(dev, fan_node,
313 							emc2305_fan_name[idx], data,
314 							&emc2305_cooling_ops);
315 
316 	if (IS_ERR(data->cdev_data[cdev_idx].cdev)) {
317 		dev_err(dev, "Failed to register cooling device %s\n", emc2305_fan_name[idx]);
318 		return PTR_ERR(data->cdev_data[cdev_idx].cdev);
319 	}
320 
321 	if (data->cdev_data[cdev_idx].cur_state > 0)
322 		/* Update pwm when temperature is above trips */
323 		pwm = EMC2305_PWM_STATE2DUTY(data->cdev_data[cdev_idx].cur_state,
324 					     data->max_state, EMC2305_FAN_MAX);
325 
326 	/* Set minimal PWM speed. */
327 	if (data->pwm_separate) {
328 		ret = emc2305_set_pwm(dev, pwm, cdev_idx);
329 		if (ret < 0)
330 			return ret;
331 	} else {
332 		for (i = 0; i < data->pwm_num; i++) {
333 			ret = emc2305_set_pwm(dev, pwm, i);
334 			if (ret < 0)
335 				return ret;
336 		}
337 	}
338 	data->cdev_data[cdev_idx].cur_state =
339 		EMC2305_PWM_DUTY2STATE(pwm, data->max_state,
340 				       EMC2305_FAN_MAX);
341 	data->cdev_data[cdev_idx].last_hwmon_state =
342 		EMC2305_PWM_DUTY2STATE(pwm, data->max_state,
343 				       EMC2305_FAN_MAX);
344 	return 0;
345 }
346 
347 static int emc2305_set_tz(struct device *dev)
348 {
349 	struct emc2305_data *data = dev_get_drvdata(dev);
350 	int i, ret;
351 
352 	if (!data->pwm_separate)
353 		return emc2305_set_single_tz(dev, dev->of_node, 0);
354 
355 	for (i = 0; i < data->pwm_num; i++) {
356 		ret = emc2305_set_single_tz(dev, dev->of_node, i + 1);
357 		if (ret)
358 			return ret;
359 	}
360 	return 0;
361 }
362 
363 static umode_t
364 emc2305_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel)
365 {
366 	int max_channel = emc2305_get_max_channel(data);
367 
368 	/* Don't show channels which are not physically connected. */
369 	if (channel >= max_channel)
370 		return 0;
371 	switch (type) {
372 	case hwmon_fan:
373 		switch (attr) {
374 		case hwmon_fan_input:
375 			return 0444;
376 		case hwmon_fan_fault:
377 			return 0444;
378 		default:
379 			break;
380 		}
381 		break;
382 	case hwmon_pwm:
383 		switch (attr) {
384 		case hwmon_pwm_input:
385 			return 0644;
386 		default:
387 			break;
388 		}
389 		break;
390 	default:
391 		break;
392 	}
393 
394 	return 0;
395 };
396 
397 static int
398 emc2305_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long val)
399 {
400 	struct emc2305_data *data = dev_get_drvdata(dev);
401 	int cdev_idx;
402 
403 	switch (type) {
404 	case hwmon_pwm:
405 		switch (attr) {
406 		case hwmon_pwm_input:
407 			/* If thermal is configured - handle PWM limit setting. */
408 			if (IS_REACHABLE(CONFIG_THERMAL)) {
409 				if (data->pwm_separate)
410 					cdev_idx = channel;
411 				else
412 					cdev_idx = 0;
413 				data->cdev_data[cdev_idx].last_hwmon_state =
414 					EMC2305_PWM_DUTY2STATE(val, data->max_state,
415 							       EMC2305_FAN_MAX);
416 				/*
417 				 * Update PWM only in case requested state is not less than the
418 				 * last thermal state.
419 				 */
420 				if (data->cdev_data[cdev_idx].last_hwmon_state >=
421 				    data->cdev_data[cdev_idx].last_thermal_state)
422 					return __emc2305_set_cur_state(data, cdev_idx,
423 							data->cdev_data[cdev_idx].last_hwmon_state);
424 				return 0;
425 			}
426 			return emc2305_set_pwm(dev, val, channel);
427 		default:
428 			break;
429 		}
430 		break;
431 	default:
432 		break;
433 	}
434 
435 	return -EOPNOTSUPP;
436 };
437 
438 static int
439 emc2305_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val)
440 {
441 	int ret;
442 
443 	switch (type) {
444 	case hwmon_fan:
445 		switch (attr) {
446 		case hwmon_fan_input:
447 			ret = emc2305_show_fan(dev, channel);
448 			if (ret < 0)
449 				return ret;
450 			*val = ret;
451 			return 0;
452 		case hwmon_fan_fault:
453 			ret = emc2305_show_fault(dev, channel);
454 			if (ret < 0)
455 				return ret;
456 			*val = ret;
457 			return 0;
458 		default:
459 			break;
460 		}
461 		break;
462 	case hwmon_pwm:
463 		switch (attr) {
464 		case hwmon_pwm_input:
465 			ret = emc2305_show_pwm(dev, channel);
466 			if (ret < 0)
467 				return ret;
468 			*val = ret;
469 			return 0;
470 		default:
471 			break;
472 		}
473 		break;
474 	default:
475 		break;
476 	}
477 
478 	return -EOPNOTSUPP;
479 };
480 
481 static const struct hwmon_ops emc2305_ops = {
482 	.is_visible = emc2305_is_visible,
483 	.read = emc2305_read,
484 	.write = emc2305_write,
485 };
486 
487 static const struct hwmon_channel_info * const emc2305_info[] = {
488 	HWMON_CHANNEL_INFO(fan,
489 			   HWMON_F_INPUT | HWMON_F_FAULT,
490 			   HWMON_F_INPUT | HWMON_F_FAULT,
491 			   HWMON_F_INPUT | HWMON_F_FAULT,
492 			   HWMON_F_INPUT | HWMON_F_FAULT,
493 			   HWMON_F_INPUT | HWMON_F_FAULT),
494 	HWMON_CHANNEL_INFO(pwm,
495 			   HWMON_PWM_INPUT,
496 			   HWMON_PWM_INPUT,
497 			   HWMON_PWM_INPUT,
498 			   HWMON_PWM_INPUT,
499 			   HWMON_PWM_INPUT),
500 	NULL
501 };
502 
503 static const struct hwmon_chip_info emc2305_chip_info = {
504 	.ops = &emc2305_ops,
505 	.info = emc2305_info,
506 };
507 
508 static int emc2305_identify(struct device *dev)
509 {
510 	struct i2c_client *client = to_i2c_client(dev);
511 	struct emc2305_data *data = i2c_get_clientdata(client);
512 	int ret;
513 
514 	ret = i2c_smbus_read_byte_data(client, EMC2305_REG_PRODUCT_ID);
515 	if (ret < 0)
516 		return ret;
517 
518 	switch (ret) {
519 	case EMC2305:
520 		data->pwm_num = 5;
521 		break;
522 	case EMC2303:
523 		data->pwm_num = 3;
524 		break;
525 	case EMC2302:
526 		data->pwm_num = 2;
527 		break;
528 	case EMC2301:
529 		data->pwm_num = 1;
530 		break;
531 	default:
532 		return -ENODEV;
533 	}
534 
535 	return 0;
536 }
537 
538 static int emc2305_of_parse_pwm_child(struct device *dev,
539 				      struct device_node *child,
540 				      struct emc2305_data *data)
541 {	u32 ch;
542 	int ret;
543 	struct of_phandle_args args;
544 
545 	ret = of_property_read_u32(child, "reg", &ch);
546 	if (ret) {
547 		dev_err(dev, "missing reg property of %pOFn\n", child);
548 		return ret;
549 	}
550 
551 	ret = of_parse_phandle_with_args(child, "pwms", "#pwm-cells", 0, &args);
552 
553 	if (ret)
554 		return ret;
555 
556 	if (args.args_count > 0) {
557 		data->pwm_freq[ch] = find_closest(args.args[0], base_freq_table,
558 						  ARRAY_SIZE(base_freq_table));
559 	} else {
560 		data->pwm_freq[ch] = base_freq_table[3];
561 	}
562 
563 	if (args.args_count > 1) {
564 		if (args.args[1] == PWM_POLARITY_NORMAL || args.args[1] == PWM_POLARITY_INVERSED)
565 			data->pwm_polarity_mask |= args.args[1] << ch;
566 		else
567 			dev_err(dev, "Wrong PWM polarity config provided: %d\n", args.args[0]);
568 	} else {
569 		data->pwm_polarity_mask |= PWM_POLARITY_NORMAL << ch;
570 	}
571 
572 	if (args.args_count > 2) {
573 		if (args.args[2] == EMC2305_PUSH_PULL || args.args[2] <= EMC2305_OPEN_DRAIN)
574 			data->pwm_output_mask |= args.args[2] << ch;
575 		else
576 			dev_err(dev, "Wrong PWM output config provided: %d\n", args.args[1]);
577 	} else {
578 		data->pwm_output_mask |= EMC2305_OPEN_DRAIN << ch;
579 	}
580 
581 	return 0;
582 }
583 
584 static int emc2305_probe_childs_from_dt(struct device *dev)
585 {
586 	struct emc2305_data *data = dev_get_drvdata(dev);
587 	struct device_node *child;
588 	int ret, count = 0;
589 
590 	data->pwm_output_mask = 0x0;
591 	data->pwm_polarity_mask = 0x0;
592 
593 	for_each_child_of_node(dev->of_node, child) {
594 		if (of_property_present(child, "reg")) {
595 			ret = emc2305_of_parse_pwm_child(dev, child, data);
596 			if (ret) {
597 				of_node_put(child);
598 				continue;
599 			}
600 			count++;
601 		}
602 	}
603 	return count;
604 }
605 
606 static int emc2305_probe(struct i2c_client *client)
607 {
608 	struct i2c_adapter *adapter = client->adapter;
609 	struct device *dev = &client->dev;
610 	struct device_node *child;
611 	struct emc2305_data *data;
612 	struct emc2305_platform_data *pdata;
613 	int vendor;
614 	int ret;
615 	int i;
616 	int pwm_childs;
617 
618 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
619 		return -ENODEV;
620 
621 	vendor = i2c_smbus_read_byte_data(client, EMC2305_REG_VENDOR);
622 	if (vendor != EMC2305_VENDOR)
623 		return -ENODEV;
624 
625 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
626 	if (!data)
627 		return -ENOMEM;
628 
629 	i2c_set_clientdata(client, data);
630 	data->client = client;
631 
632 	ret = emc2305_identify(dev);
633 	if (ret)
634 		return ret;
635 
636 	pwm_childs = emc2305_probe_childs_from_dt(dev);
637 
638 	pdata = dev_get_platdata(&client->dev);
639 
640 	if (!pwm_childs) {
641 		if (pdata) {
642 			if (!pdata->max_state || pdata->max_state > EMC2305_FAN_MAX_STATE)
643 				return -EINVAL;
644 			data->max_state = pdata->max_state;
645 			/*
646 			 * Validate a number of active PWM channels. Note that
647 			 * configured number can be less than the actual maximum
648 			 * supported by the device.
649 			 */
650 			if (!pdata->pwm_num || pdata->pwm_num > EMC2305_PWM_MAX)
651 				return -EINVAL;
652 			data->pwm_num = pdata->pwm_num;
653 			data->pwm_output_mask = pdata->pwm_output_mask;
654 			data->pwm_polarity_mask = pdata->pwm_polarity_mask;
655 			data->pwm_separate = pdata->pwm_separate;
656 			for (i = 0; i < EMC2305_PWM_MAX; i++) {
657 				data->pwm_min[i] = pdata->pwm_min[i];
658 				data->pwm_freq[i] = pdata->pwm_freq[i];
659 			}
660 		} else {
661 			data->max_state = EMC2305_FAN_MAX_STATE;
662 			data->pwm_separate = false;
663 			data->pwm_output_mask = EMC2305_DEFAULT_OUTPUT;
664 			data->pwm_polarity_mask = EMC2305_DEFAULT_POLARITY;
665 			for (i = 0; i < EMC2305_PWM_MAX; i++) {
666 				data->pwm_min[i] = EMC2305_FAN_MIN;
667 				data->pwm_freq[i] = base_freq_table[3];
668 			}
669 		}
670 	} else {
671 		data->max_state = EMC2305_FAN_MAX_STATE;
672 		data->pwm_separate = false;
673 		for (i = 0; i < EMC2305_PWM_MAX; i++)
674 			data->pwm_min[i] = EMC2305_FAN_MIN;
675 	}
676 
677 	data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "emc2305", data,
678 							       &emc2305_chip_info, NULL);
679 	if (IS_ERR(data->hwmon_dev))
680 		return PTR_ERR(data->hwmon_dev);
681 
682 	if (IS_REACHABLE(CONFIG_THERMAL)) {
683 		/* Parse and check for the available PWM child nodes */
684 		if (pwm_childs > 0) {
685 			i = 0;
686 			for_each_child_of_node(dev->of_node, child) {
687 				ret = emc2305_set_single_tz(dev, child, i);
688 				if (ret != 0)
689 					return ret;
690 				i++;
691 			}
692 		} else {
693 			ret = emc2305_set_tz(dev);
694 			if (ret != 0)
695 				return ret;
696 		}
697 	}
698 
699 	ret = i2c_smbus_write_byte_data(client, EMC2305_REG_DRIVE_PWM_OUT,
700 					data->pwm_output_mask);
701 	if (ret < 0)
702 		dev_err(dev, "Failed to configure pwm output, using default\n");
703 
704 	ret = i2c_smbus_write_byte_data(client, EMC2305_REG_POLARITY,
705 					data->pwm_polarity_mask);
706 	if (ret < 0)
707 		dev_err(dev, "Failed to configure pwm polarity, using default\n");
708 
709 	for (i = 0; i < data->pwm_num; i++) {
710 		ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_MIN_DRIVE(i),
711 						data->pwm_min[i]);
712 		if (ret < 0)
713 			return ret;
714 	}
715 
716 	return 0;
717 }
718 
719 static const struct of_device_id of_emc2305_match_table[] = {
720 	{ .compatible = "microchip,emc2305", },
721 	{},
722 };
723 MODULE_DEVICE_TABLE(of, of_emc2305_match_table);
724 
725 static struct i2c_driver emc2305_driver = {
726 	.driver = {
727 		.name = "emc2305",
728 		.of_match_table = of_emc2305_match_table,
729 	},
730 	.probe = emc2305_probe,
731 	.id_table = emc2305_ids,
732 };
733 
734 module_i2c_driver(emc2305_driver);
735 
736 MODULE_AUTHOR("Nvidia");
737 MODULE_DESCRIPTION("Microchip EMC2305 fan controller driver");
738 MODULE_LICENSE("GPL");
739