xref: /openbmc/linux/drivers/hwmon/adt7411.c (revision e2c75e76)
1 /*
2  *  Driver for the ADT7411 (I2C/SPI 8 channel 10 bit ADC & temperature-sensor)
3  *
4  *  Copyright (C) 2008, 2010 Pengutronix
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License version 2 as
8  *  published by the Free Software Foundation.
9  *
10  *  TODO: SPI, use power-down mode for suspend?, interrupt handling?
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/err.h>
17 #include <linux/mutex.h>
18 #include <linux/jiffies.h>
19 #include <linux/i2c.h>
20 #include <linux/hwmon.h>
21 #include <linux/hwmon-sysfs.h>
22 #include <linux/slab.h>
23 
24 #define ADT7411_REG_STAT_1			0x00
25 #define ADT7411_STAT_1_INT_TEMP_HIGH		BIT(0)
26 #define ADT7411_STAT_1_INT_TEMP_LOW		BIT(1)
27 #define ADT7411_STAT_1_EXT_TEMP_HIGH_AIN1	BIT(2)
28 #define ADT7411_STAT_1_EXT_TEMP_LOW		BIT(3)
29 #define ADT7411_STAT_1_EXT_TEMP_FAULT		BIT(4)
30 #define ADT7411_STAT_1_AIN2			BIT(5)
31 #define ADT7411_STAT_1_AIN3			BIT(6)
32 #define ADT7411_STAT_1_AIN4			BIT(7)
33 #define ADT7411_REG_STAT_2			0x01
34 #define ADT7411_STAT_2_AIN5			BIT(0)
35 #define ADT7411_STAT_2_AIN6			BIT(1)
36 #define ADT7411_STAT_2_AIN7			BIT(2)
37 #define ADT7411_STAT_2_AIN8			BIT(3)
38 #define ADT7411_STAT_2_VDD			BIT(4)
39 #define ADT7411_REG_INT_TEMP_VDD_LSB		0x03
40 #define ADT7411_REG_EXT_TEMP_AIN14_LSB		0x04
41 #define ADT7411_REG_VDD_MSB			0x06
42 #define ADT7411_REG_INT_TEMP_MSB		0x07
43 #define ADT7411_REG_EXT_TEMP_AIN1_MSB		0x08
44 
45 #define ADT7411_REG_CFG1			0x18
46 #define ADT7411_CFG1_START_MONITOR		BIT(0)
47 #define ADT7411_CFG1_RESERVED_BIT1		BIT(1)
48 #define ADT7411_CFG1_EXT_TDM			BIT(2)
49 #define ADT7411_CFG1_RESERVED_BIT3		BIT(3)
50 
51 #define ADT7411_REG_CFG2			0x19
52 #define ADT7411_CFG2_DISABLE_AVG		BIT(5)
53 
54 #define ADT7411_REG_CFG3			0x1a
55 #define ADT7411_CFG3_ADC_CLK_225		BIT(0)
56 #define ADT7411_CFG3_RESERVED_BIT1		BIT(1)
57 #define ADT7411_CFG3_RESERVED_BIT2		BIT(2)
58 #define ADT7411_CFG3_RESERVED_BIT3		BIT(3)
59 #define ADT7411_CFG3_REF_VDD			BIT(4)
60 
61 #define ADT7411_REG_VDD_HIGH			0x23
62 #define ADT7411_REG_VDD_LOW			0x24
63 #define ADT7411_REG_TEMP_HIGH(nr)		(0x25 + 2 * (nr))
64 #define ADT7411_REG_TEMP_LOW(nr)		(0x26 + 2 * (nr))
65 #define ADT7411_REG_IN_HIGH(nr)		((nr) > 1 \
66 						  ? 0x2b + 2 * ((nr)-2) \
67 						  : 0x27)
68 #define ADT7411_REG_IN_LOW(nr)			((nr) > 1 \
69 						  ? 0x2c + 2 * ((nr)-2) \
70 						  : 0x28)
71 
72 #define ADT7411_REG_DEVICE_ID			0x4d
73 #define ADT7411_REG_MANUFACTURER_ID		0x4e
74 
75 #define ADT7411_DEVICE_ID			0x2
76 #define ADT7411_MANUFACTURER_ID			0x41
77 
78 static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };
79 
80 static const u8 adt7411_in_alarm_reg[] = {
81 	ADT7411_REG_STAT_2,
82 	ADT7411_REG_STAT_1,
83 	ADT7411_REG_STAT_1,
84 	ADT7411_REG_STAT_1,
85 	ADT7411_REG_STAT_1,
86 	ADT7411_REG_STAT_2,
87 	ADT7411_REG_STAT_2,
88 	ADT7411_REG_STAT_2,
89 	ADT7411_REG_STAT_2,
90 };
91 
92 static const u8 adt7411_in_alarm_bits[] = {
93 	ADT7411_STAT_2_VDD,
94 	ADT7411_STAT_1_EXT_TEMP_HIGH_AIN1,
95 	ADT7411_STAT_1_AIN2,
96 	ADT7411_STAT_1_AIN3,
97 	ADT7411_STAT_1_AIN4,
98 	ADT7411_STAT_2_AIN5,
99 	ADT7411_STAT_2_AIN6,
100 	ADT7411_STAT_2_AIN7,
101 	ADT7411_STAT_2_AIN8,
102 };
103 
104 struct adt7411_data {
105 	struct mutex device_lock;	/* for "atomic" device accesses */
106 	struct mutex update_lock;
107 	unsigned long next_update;
108 	long vref_cached;
109 	struct i2c_client *client;
110 	bool use_ext_temp;
111 };
112 
113 /*
114  * When reading a register containing (up to 4) lsb, all associated
115  * msb-registers get locked by the hardware. After _one_ of those msb is read,
116  * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
117  * is protected here with a mutex, too.
118  */
119 static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
120 				u8 msb_reg, u8 lsb_shift)
121 {
122 	struct adt7411_data *data = i2c_get_clientdata(client);
123 	int val, tmp;
124 
125 	mutex_lock(&data->device_lock);
126 
127 	val = i2c_smbus_read_byte_data(client, lsb_reg);
128 	if (val < 0)
129 		goto exit_unlock;
130 
131 	tmp = (val >> lsb_shift) & 3;
132 	val = i2c_smbus_read_byte_data(client, msb_reg);
133 
134 	if (val >= 0)
135 		val = (val << 2) | tmp;
136 
137  exit_unlock:
138 	mutex_unlock(&data->device_lock);
139 
140 	return val;
141 }
142 
143 static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
144 				bool flag)
145 {
146 	struct adt7411_data *data = i2c_get_clientdata(client);
147 	int ret, val;
148 
149 	mutex_lock(&data->device_lock);
150 
151 	ret = i2c_smbus_read_byte_data(client, reg);
152 	if (ret < 0)
153 		goto exit_unlock;
154 
155 	if (flag)
156 		val = ret | bit;
157 	else
158 		val = ret & ~bit;
159 
160 	ret = i2c_smbus_write_byte_data(client, reg, val);
161 
162  exit_unlock:
163 	mutex_unlock(&data->device_lock);
164 	return ret;
165 }
166 
167 static ssize_t adt7411_show_bit(struct device *dev,
168 				struct device_attribute *attr, char *buf)
169 {
170 	struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
171 	struct adt7411_data *data = dev_get_drvdata(dev);
172 	struct i2c_client *client = data->client;
173 	int ret = i2c_smbus_read_byte_data(client, attr2->index);
174 
175 	return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
176 }
177 
178 static ssize_t adt7411_set_bit(struct device *dev,
179 			       struct device_attribute *attr, const char *buf,
180 			       size_t count)
181 {
182 	struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
183 	struct adt7411_data *data = dev_get_drvdata(dev);
184 	struct i2c_client *client = data->client;
185 	int ret;
186 	unsigned long flag;
187 
188 	ret = kstrtoul(buf, 0, &flag);
189 	if (ret || flag > 1)
190 		return -EINVAL;
191 
192 	ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
193 
194 	/* force update */
195 	mutex_lock(&data->update_lock);
196 	data->next_update = jiffies;
197 	mutex_unlock(&data->update_lock);
198 
199 	return ret < 0 ? ret : count;
200 }
201 
202 #define ADT7411_BIT_ATTR(__name, __reg, __bit) \
203 	SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
204 	adt7411_set_bit, __bit, __reg)
205 
206 static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
207 static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
208 static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);
209 
210 static struct attribute *adt7411_attrs[] = {
211 	&sensor_dev_attr_no_average.dev_attr.attr,
212 	&sensor_dev_attr_fast_sampling.dev_attr.attr,
213 	&sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
214 	NULL
215 };
216 ATTRIBUTE_GROUPS(adt7411);
217 
218 static int adt7411_read_in_alarm(struct device *dev, int channel, long *val)
219 {
220 	struct adt7411_data *data = dev_get_drvdata(dev);
221 	struct i2c_client *client = data->client;
222 	int ret;
223 
224 	ret = i2c_smbus_read_byte_data(client, adt7411_in_alarm_reg[channel]);
225 	if (ret < 0)
226 		return ret;
227 	*val = !!(ret & adt7411_in_alarm_bits[channel]);
228 	return 0;
229 }
230 
231 static int adt7411_read_in_vdd(struct device *dev, u32 attr, long *val)
232 {
233 	struct adt7411_data *data = dev_get_drvdata(dev);
234 	struct i2c_client *client = data->client;
235 	int ret;
236 
237 	switch (attr) {
238 	case hwmon_in_input:
239 		ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
240 					  ADT7411_REG_VDD_MSB, 2);
241 		if (ret < 0)
242 			return ret;
243 		*val = ret * 7000 / 1024;
244 		return 0;
245 	case hwmon_in_min:
246 		ret = i2c_smbus_read_byte_data(client, ADT7411_REG_VDD_LOW);
247 		if (ret < 0)
248 			return ret;
249 		*val = ret * 7000 / 256;
250 		return 0;
251 	case hwmon_in_max:
252 		ret = i2c_smbus_read_byte_data(client, ADT7411_REG_VDD_HIGH);
253 		if (ret < 0)
254 			return ret;
255 		*val = ret * 7000 / 256;
256 		return 0;
257 	case hwmon_in_alarm:
258 		return adt7411_read_in_alarm(dev, 0, val);
259 	default:
260 		return -EOPNOTSUPP;
261 	}
262 }
263 
264 static int adt7411_update_vref(struct device *dev)
265 {
266 	struct adt7411_data *data = dev_get_drvdata(dev);
267 	struct i2c_client *client = data->client;
268 	int val;
269 
270 	if (time_after_eq(jiffies, data->next_update)) {
271 		val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
272 		if (val < 0)
273 			return val;
274 
275 		if (val & ADT7411_CFG3_REF_VDD) {
276 			val = adt7411_read_in_vdd(dev, hwmon_in_input,
277 						  &data->vref_cached);
278 			if (val < 0)
279 				return val;
280 		} else {
281 			data->vref_cached = 2250;
282 		}
283 
284 		data->next_update = jiffies + HZ;
285 	}
286 
287 	return 0;
288 }
289 
290 static int adt7411_read_in_chan(struct device *dev, u32 attr, int channel,
291 				long *val)
292 {
293 	struct adt7411_data *data = dev_get_drvdata(dev);
294 	struct i2c_client *client = data->client;
295 
296 	int ret;
297 	int reg, lsb_reg, lsb_shift;
298 	int nr = channel - 1;
299 
300 	mutex_lock(&data->update_lock);
301 	ret = adt7411_update_vref(dev);
302 	if (ret < 0)
303 		goto exit_unlock;
304 
305 	switch (attr) {
306 	case hwmon_in_input:
307 		lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
308 		lsb_shift = 2 * (nr & 0x03);
309 		ret = adt7411_read_10_bit(client, lsb_reg,
310 					  ADT7411_REG_EXT_TEMP_AIN1_MSB + nr,
311 					  lsb_shift);
312 		if (ret < 0)
313 			goto exit_unlock;
314 		*val = ret * data->vref_cached / 1024;
315 		ret = 0;
316 		break;
317 	case hwmon_in_min:
318 	case hwmon_in_max:
319 		reg = (attr == hwmon_in_min)
320 			? ADT7411_REG_IN_LOW(channel)
321 			: ADT7411_REG_IN_HIGH(channel);
322 		ret = i2c_smbus_read_byte_data(client, reg);
323 		if (ret < 0)
324 			goto exit_unlock;
325 		*val = ret * data->vref_cached / 256;
326 		ret = 0;
327 		break;
328 	case hwmon_in_alarm:
329 		ret = adt7411_read_in_alarm(dev, channel, val);
330 		break;
331 	default:
332 		ret = -EOPNOTSUPP;
333 		break;
334 	}
335  exit_unlock:
336 	mutex_unlock(&data->update_lock);
337 	return ret;
338 }
339 
340 static int adt7411_read_in(struct device *dev, u32 attr, int channel,
341 			   long *val)
342 {
343 	if (channel == 0)
344 		return adt7411_read_in_vdd(dev, attr, val);
345 	else
346 		return adt7411_read_in_chan(dev, attr, channel, val);
347 }
348 
349 
350 static int adt7411_read_temp_alarm(struct device *dev, u32 attr, int channel,
351 				   long *val)
352 {
353 	struct adt7411_data *data = dev_get_drvdata(dev);
354 	struct i2c_client *client = data->client;
355 	int ret, bit;
356 
357 	ret = i2c_smbus_read_byte_data(client, ADT7411_REG_STAT_1);
358 	if (ret < 0)
359 		return ret;
360 
361 	switch (attr) {
362 	case hwmon_temp_min_alarm:
363 		bit = channel ? ADT7411_STAT_1_EXT_TEMP_LOW
364 			      : ADT7411_STAT_1_INT_TEMP_LOW;
365 		break;
366 	case hwmon_temp_max_alarm:
367 		bit = channel ? ADT7411_STAT_1_EXT_TEMP_HIGH_AIN1
368 			      : ADT7411_STAT_1_INT_TEMP_HIGH;
369 		break;
370 	case hwmon_temp_fault:
371 		bit = ADT7411_STAT_1_EXT_TEMP_FAULT;
372 		break;
373 	default:
374 		return -EOPNOTSUPP;
375 	}
376 
377 	*val = !!(ret & bit);
378 	return 0;
379 }
380 
381 static int adt7411_read_temp(struct device *dev, u32 attr, int channel,
382 			     long *val)
383 {
384 	struct adt7411_data *data = dev_get_drvdata(dev);
385 	struct i2c_client *client = data->client;
386 	int ret, reg, regl, regh;
387 
388 	switch (attr) {
389 	case hwmon_temp_input:
390 		regl = channel ? ADT7411_REG_EXT_TEMP_AIN14_LSB :
391 				 ADT7411_REG_INT_TEMP_VDD_LSB;
392 		regh = channel ? ADT7411_REG_EXT_TEMP_AIN1_MSB :
393 				 ADT7411_REG_INT_TEMP_MSB;
394 		ret = adt7411_read_10_bit(client, regl, regh, 0);
395 		if (ret < 0)
396 			return ret;
397 		ret = ret & 0x200 ? ret - 0x400 : ret; /* 10 bit signed */
398 		*val = ret * 250;
399 		return 0;
400 	case hwmon_temp_min:
401 	case hwmon_temp_max:
402 		reg = (attr == hwmon_temp_min)
403 			? ADT7411_REG_TEMP_LOW(channel)
404 			: ADT7411_REG_TEMP_HIGH(channel);
405 		ret = i2c_smbus_read_byte_data(client, reg);
406 		if (ret < 0)
407 			return ret;
408 		ret = ret & 0x80 ? ret - 0x100 : ret; /* 8 bit signed */
409 		*val = ret * 1000;
410 		return 0;
411 	case hwmon_temp_min_alarm:
412 	case hwmon_temp_max_alarm:
413 	case hwmon_temp_fault:
414 		return adt7411_read_temp_alarm(dev, attr, channel, val);
415 	default:
416 		return -EOPNOTSUPP;
417 	}
418 }
419 
420 static int adt7411_read(struct device *dev, enum hwmon_sensor_types type,
421 			u32 attr, int channel, long *val)
422 {
423 	switch (type) {
424 	case hwmon_in:
425 		return adt7411_read_in(dev, attr, channel, val);
426 	case hwmon_temp:
427 		return adt7411_read_temp(dev, attr, channel, val);
428 	default:
429 		return -EOPNOTSUPP;
430 	}
431 }
432 
433 static int adt7411_write_in_vdd(struct device *dev, u32 attr, long val)
434 {
435 	struct adt7411_data *data = dev_get_drvdata(dev);
436 	struct i2c_client *client = data->client;
437 	int reg;
438 
439 	val = clamp_val(val, 0, 255 * 7000 / 256);
440 	val = DIV_ROUND_CLOSEST(val * 256, 7000);
441 
442 	switch (attr) {
443 	case hwmon_in_min:
444 		reg = ADT7411_REG_VDD_LOW;
445 		break;
446 	case hwmon_in_max:
447 		reg = ADT7411_REG_VDD_HIGH;
448 		break;
449 	default:
450 		return -EOPNOTSUPP;
451 	}
452 
453 	return i2c_smbus_write_byte_data(client, reg, val);
454 }
455 
456 static int adt7411_write_in_chan(struct device *dev, u32 attr, int channel,
457 				 long val)
458 {
459 	struct adt7411_data *data = dev_get_drvdata(dev);
460 	struct i2c_client *client = data->client;
461 	int ret, reg;
462 
463 	mutex_lock(&data->update_lock);
464 	ret = adt7411_update_vref(dev);
465 	if (ret < 0)
466 		goto exit_unlock;
467 	val = clamp_val(val, 0, 255 * data->vref_cached / 256);
468 	val = DIV_ROUND_CLOSEST(val * 256, data->vref_cached);
469 
470 	switch (attr) {
471 	case hwmon_in_min:
472 		reg = ADT7411_REG_IN_LOW(channel);
473 		break;
474 	case hwmon_in_max:
475 		reg = ADT7411_REG_IN_HIGH(channel);
476 		break;
477 	default:
478 		ret = -EOPNOTSUPP;
479 		goto exit_unlock;
480 	}
481 
482 	ret = i2c_smbus_write_byte_data(client, reg, val);
483  exit_unlock:
484 	mutex_unlock(&data->update_lock);
485 	return ret;
486 }
487 
488 static int adt7411_write_in(struct device *dev, u32 attr, int channel,
489 			    long val)
490 {
491 	if (channel == 0)
492 		return adt7411_write_in_vdd(dev, attr, val);
493 	else
494 		return adt7411_write_in_chan(dev, attr, channel, val);
495 }
496 
497 static int adt7411_write_temp(struct device *dev, u32 attr, int channel,
498 			      long val)
499 {
500 	struct adt7411_data *data = dev_get_drvdata(dev);
501 	struct i2c_client *client = data->client;
502 	int reg;
503 
504 	val = clamp_val(val, -128000, 127000);
505 	val = DIV_ROUND_CLOSEST(val, 1000);
506 
507 	switch (attr) {
508 	case hwmon_temp_min:
509 		reg = ADT7411_REG_TEMP_LOW(channel);
510 		break;
511 	case hwmon_temp_max:
512 		reg = ADT7411_REG_TEMP_HIGH(channel);
513 		break;
514 	default:
515 		return -EOPNOTSUPP;
516 	}
517 
518 	return i2c_smbus_write_byte_data(client, reg, val);
519 }
520 
521 static int adt7411_write(struct device *dev, enum hwmon_sensor_types type,
522 			 u32 attr, int channel, long val)
523 {
524 	switch (type) {
525 	case hwmon_in:
526 		return adt7411_write_in(dev, attr, channel, val);
527 	case hwmon_temp:
528 		return adt7411_write_temp(dev, attr, channel, val);
529 	default:
530 		return -EOPNOTSUPP;
531 	}
532 }
533 
534 static umode_t adt7411_is_visible(const void *_data,
535 				  enum hwmon_sensor_types type,
536 				  u32 attr, int channel)
537 {
538 	const struct adt7411_data *data = _data;
539 	bool visible;
540 
541 	switch (type) {
542 	case hwmon_in:
543 		visible = channel == 0 || channel >= 3 || !data->use_ext_temp;
544 		switch (attr) {
545 		case hwmon_in_input:
546 		case hwmon_in_alarm:
547 			return visible ? S_IRUGO : 0;
548 		case hwmon_in_min:
549 		case hwmon_in_max:
550 			return visible ? S_IRUGO | S_IWUSR : 0;
551 		}
552 		break;
553 	case hwmon_temp:
554 		visible = channel == 0 || data->use_ext_temp;
555 		switch (attr) {
556 		case hwmon_temp_input:
557 		case hwmon_temp_min_alarm:
558 		case hwmon_temp_max_alarm:
559 		case hwmon_temp_fault:
560 			return visible ? S_IRUGO : 0;
561 		case hwmon_temp_min:
562 		case hwmon_temp_max:
563 			return visible ? S_IRUGO | S_IWUSR : 0;
564 		}
565 		break;
566 	default:
567 		break;
568 	}
569 	return 0;
570 }
571 
572 static int adt7411_detect(struct i2c_client *client,
573 			  struct i2c_board_info *info)
574 {
575 	int val;
576 
577 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
578 		return -ENODEV;
579 
580 	val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
581 	if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
582 		dev_dbg(&client->dev,
583 			"Wrong manufacturer ID. Got %d, expected %d\n",
584 			val, ADT7411_MANUFACTURER_ID);
585 		return -ENODEV;
586 	}
587 
588 	val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
589 	if (val < 0 || val != ADT7411_DEVICE_ID) {
590 		dev_dbg(&client->dev,
591 			"Wrong device ID. Got %d, expected %d\n",
592 			val, ADT7411_DEVICE_ID);
593 		return -ENODEV;
594 	}
595 
596 	strlcpy(info->type, "adt7411", I2C_NAME_SIZE);
597 
598 	return 0;
599 }
600 
601 static int adt7411_init_device(struct adt7411_data *data)
602 {
603 	int ret;
604 	u8 val;
605 
606 	ret = i2c_smbus_read_byte_data(data->client, ADT7411_REG_CFG3);
607 	if (ret < 0)
608 		return ret;
609 
610 	/*
611 	 * We must only write zero to bit 1 and bit 2 and only one to bit 3
612 	 * according to the datasheet.
613 	 */
614 	val = ret;
615 	val &= ~(ADT7411_CFG3_RESERVED_BIT1 | ADT7411_CFG3_RESERVED_BIT2);
616 	val |= ADT7411_CFG3_RESERVED_BIT3;
617 
618 	ret = i2c_smbus_write_byte_data(data->client, ADT7411_REG_CFG3, val);
619 	if (ret < 0)
620 		return ret;
621 
622 	ret = i2c_smbus_read_byte_data(data->client, ADT7411_REG_CFG1);
623 	if (ret < 0)
624 		return ret;
625 
626 	data->use_ext_temp = ret & ADT7411_CFG1_EXT_TDM;
627 
628 	/*
629 	 * We must only write zero to bit 1 and only one to bit 3 according to
630 	 * the datasheet.
631 	 */
632 	val = ret;
633 	val &= ~ADT7411_CFG1_RESERVED_BIT1;
634 	val |= ADT7411_CFG1_RESERVED_BIT3;
635 
636 	/* enable monitoring */
637 	val |= ADT7411_CFG1_START_MONITOR;
638 
639 	return i2c_smbus_write_byte_data(data->client, ADT7411_REG_CFG1, val);
640 }
641 
642 static const u32 adt7411_in_config[] = {
643 	HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
644 	HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
645 	HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
646 	HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
647 	HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
648 	HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
649 	HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
650 	HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
651 	HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
652 	0
653 };
654 
655 static const struct hwmon_channel_info adt7411_in = {
656 	.type = hwmon_in,
657 	.config = adt7411_in_config,
658 };
659 
660 static const u32 adt7411_temp_config[] = {
661 	HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MIN_ALARM |
662 		HWMON_T_MAX | HWMON_T_MAX_ALARM,
663 	HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MIN_ALARM |
664 		HWMON_T_MAX | HWMON_T_MAX_ALARM | HWMON_T_FAULT,
665 	0
666 };
667 
668 static const struct hwmon_channel_info adt7411_temp = {
669 	.type = hwmon_temp,
670 	.config = adt7411_temp_config,
671 };
672 
673 static const struct hwmon_channel_info *adt7411_info[] = {
674 	&adt7411_in,
675 	&adt7411_temp,
676 	NULL
677 };
678 
679 static const struct hwmon_ops adt7411_hwmon_ops = {
680 	.is_visible = adt7411_is_visible,
681 	.read = adt7411_read,
682 	.write = adt7411_write,
683 };
684 
685 static const struct hwmon_chip_info adt7411_chip_info = {
686 	.ops = &adt7411_hwmon_ops,
687 	.info = adt7411_info,
688 };
689 
690 static int adt7411_probe(struct i2c_client *client,
691 				   const struct i2c_device_id *id)
692 {
693 	struct device *dev = &client->dev;
694 	struct adt7411_data *data;
695 	struct device *hwmon_dev;
696 	int ret;
697 
698 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
699 	if (!data)
700 		return -ENOMEM;
701 
702 	i2c_set_clientdata(client, data);
703 	data->client = client;
704 	mutex_init(&data->device_lock);
705 	mutex_init(&data->update_lock);
706 
707 	ret = adt7411_init_device(data);
708 	if (ret < 0)
709 		return ret;
710 
711 	/* force update on first occasion */
712 	data->next_update = jiffies;
713 
714 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
715 							 data,
716 							 &adt7411_chip_info,
717 							 adt7411_groups);
718 	return PTR_ERR_OR_ZERO(hwmon_dev);
719 }
720 
721 static const struct i2c_device_id adt7411_id[] = {
722 	{ "adt7411", 0 },
723 	{ }
724 };
725 MODULE_DEVICE_TABLE(i2c, adt7411_id);
726 
727 static struct i2c_driver adt7411_driver = {
728 	.driver		= {
729 		.name		= "adt7411",
730 	},
731 	.probe  = adt7411_probe,
732 	.id_table = adt7411_id,
733 	.detect = adt7411_detect,
734 	.address_list = normal_i2c,
735 	.class = I2C_CLASS_HWMON,
736 };
737 
738 module_i2c_driver(adt7411_driver);
739 
740 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
741 	"Wolfram Sang <w.sang@pengutronix.de>");
742 MODULE_DESCRIPTION("ADT7411 driver");
743 MODULE_LICENSE("GPL v2");
744