xref: /linux/drivers/hwmon/w83l786ng.c (revision d26270061ae66b915138af7cd73ca6f8b85e6b44)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * w83l786ng.c - Linux kernel driver for hardware monitoring
4  * Copyright (c) 2007 Kevin Lo <kevlo@kevlo.org>
5  */
6 
7 /*
8  * Supports following chips:
9  *
10  * Chip		#vin	#fanin	#pwm	#temp	wchipid	vendid	i2c	ISA
11  * w83l786ng	3	2	2	2	0x7b	0x5ca3	yes	no
12  */
13 
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/i2c.h>
18 #include <linux/hwmon.h>
19 #include <linux/hwmon-sysfs.h>
20 #include <linux/err.h>
21 #include <linux/mutex.h>
22 #include <linux/jiffies.h>
23 
24 /* Addresses to scan */
25 static const unsigned short normal_i2c[] = { 0x2e, 0x2f, I2C_CLIENT_END };
26 
27 /* Insmod parameters */
28 
29 static bool reset;
30 module_param(reset, bool, 0);
31 MODULE_PARM_DESC(reset, "Set to 1 to reset chip, not recommended");
32 
33 #define W83L786NG_REG_IN_MIN(nr)	(0x2C + (nr) * 2)
34 #define W83L786NG_REG_IN_MAX(nr)	(0x2B + (nr) * 2)
35 #define W83L786NG_REG_IN(nr)		((nr) + 0x20)
36 
37 #define W83L786NG_REG_FAN(nr)		((nr) + 0x28)
38 #define W83L786NG_REG_FAN_MIN(nr)	((nr) + 0x3B)
39 
40 #define W83L786NG_REG_CONFIG		0x40
41 #define W83L786NG_REG_ALARM1		0x41
42 #define W83L786NG_REG_ALARM2		0x42
43 #define W83L786NG_REG_GPIO_EN		0x47
44 #define W83L786NG_REG_MAN_ID2		0x4C
45 #define W83L786NG_REG_MAN_ID1		0x4D
46 #define W83L786NG_REG_CHIP_ID		0x4E
47 
48 #define W83L786NG_REG_DIODE		0x53
49 #define W83L786NG_REG_FAN_DIV		0x54
50 #define W83L786NG_REG_FAN_CFG		0x80
51 
52 #define W83L786NG_REG_TOLERANCE		0x8D
53 
54 static const u8 W83L786NG_REG_TEMP[2][3] = {
55 	{ 0x25,		/* TEMP 0 in DataSheet */
56 	  0x35,		/* TEMP 0 Over in DataSheet */
57 	  0x36 },	/* TEMP 0 Hyst in DataSheet */
58 	{ 0x26,		/* TEMP 1 in DataSheet */
59 	  0x37,		/* TEMP 1 Over in DataSheet */
60 	  0x38 }	/* TEMP 1 Hyst in DataSheet */
61 };
62 
63 static const u8 W83L786NG_PWM_MODE_SHIFT[] = {6, 7};
64 static const u8 W83L786NG_PWM_ENABLE_SHIFT[] = {2, 4};
65 
66 /* FAN Duty Cycle, be used to control */
67 static const u8 W83L786NG_REG_PWM[] = {0x81, 0x87};
68 
69 
70 static inline u8
71 FAN_TO_REG(long rpm, int div)
72 {
73 	if (rpm == 0)
74 		return 255;
75 	rpm = clamp_val(rpm, 1, 1000000);
76 	return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
77 }
78 
79 #define FAN_FROM_REG(val, div)	((val) == 0   ? -1 : \
80 				((val) == 255 ? 0 : \
81 				1350000 / ((val) * (div))))
82 
83 /* for temp */
84 #define TEMP_TO_REG(val)	(clamp_val(((val) < 0 ? (val) + 0x100 * 1000 \
85 						      : (val)) / 1000, 0, 0xff))
86 #define TEMP_FROM_REG(val)	(((val) & 0x80 ? \
87 				  (val) - 0x100 : (val)) * 1000)
88 
89 /*
90  * The analog voltage inputs have 8mV LSB. Since the sysfs output is
91  * in mV as would be measured on the chip input pin, need to just
92  * multiply/divide by 8 to translate from/to register values.
93  */
94 #define IN_TO_REG(val)		(clamp_val((((val) + 4) / 8), 0, 255))
95 #define IN_FROM_REG(val)	((val) * 8)
96 
97 #define DIV_FROM_REG(val)	(1 << (val))
98 
99 static inline u8
100 DIV_TO_REG(long val)
101 {
102 	int i;
103 	val = clamp_val(val, 1, 128) >> 1;
104 	for (i = 0; i < 7; i++) {
105 		if (val == 0)
106 			break;
107 		val >>= 1;
108 	}
109 	return (u8)i;
110 }
111 
112 struct w83l786ng_data {
113 	struct i2c_client *client;
114 	struct mutex update_lock;
115 	bool valid;			/* true if following fields are valid */
116 	unsigned long last_updated;	/* In jiffies */
117 	unsigned long last_nonvolatile;	/* In jiffies, last time we update the
118 					 * nonvolatile registers */
119 
120 	u8 in[3];
121 	u8 in_max[3];
122 	u8 in_min[3];
123 	u8 fan[2];
124 	u8 fan_div[2];
125 	u8 fan_min[2];
126 	u8 temp_type[2];
127 	u8 temp[2][3];
128 	u8 pwm[2];
129 	u8 pwm_mode[2];	/* 0->DC variable voltage
130 			 * 1->PWM variable duty cycle */
131 
132 	u8 pwm_enable[2]; /* 1->manual
133 			   * 2->thermal cruise (also called SmartFan I) */
134 	u8 tolerance[2];
135 };
136 
137 static u8
138 w83l786ng_read_value(struct i2c_client *client, u8 reg)
139 {
140 	return i2c_smbus_read_byte_data(client, reg);
141 }
142 
143 static int
144 w83l786ng_write_value(struct i2c_client *client, u8 reg, u8 value)
145 {
146 	return i2c_smbus_write_byte_data(client, reg, value);
147 }
148 
149 static struct w83l786ng_data *w83l786ng_update_device(struct device *dev)
150 {
151 	struct w83l786ng_data *data = dev_get_drvdata(dev);
152 	struct i2c_client *client = data->client;
153 	int i, j;
154 	u8 reg_tmp, pwmcfg;
155 
156 	mutex_lock(&data->update_lock);
157 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
158 	    || !data->valid) {
159 		dev_dbg(&client->dev, "Updating w83l786ng data.\n");
160 
161 		/* Update the voltages measured value and limits */
162 		for (i = 0; i < 3; i++) {
163 			data->in[i] = w83l786ng_read_value(client,
164 			    W83L786NG_REG_IN(i));
165 			data->in_min[i] = w83l786ng_read_value(client,
166 			    W83L786NG_REG_IN_MIN(i));
167 			data->in_max[i] = w83l786ng_read_value(client,
168 			    W83L786NG_REG_IN_MAX(i));
169 		}
170 
171 		/* Update the fan counts and limits */
172 		for (i = 0; i < 2; i++) {
173 			data->fan[i] = w83l786ng_read_value(client,
174 			    W83L786NG_REG_FAN(i));
175 			data->fan_min[i] = w83l786ng_read_value(client,
176 			    W83L786NG_REG_FAN_MIN(i));
177 		}
178 
179 		/* Update the fan divisor */
180 		reg_tmp = w83l786ng_read_value(client, W83L786NG_REG_FAN_DIV);
181 		data->fan_div[0] = reg_tmp & 0x07;
182 		data->fan_div[1] = (reg_tmp >> 4) & 0x07;
183 
184 		pwmcfg = w83l786ng_read_value(client, W83L786NG_REG_FAN_CFG);
185 		for (i = 0; i < 2; i++) {
186 			data->pwm_mode[i] =
187 			    ((pwmcfg >> W83L786NG_PWM_MODE_SHIFT[i]) & 1)
188 			    ? 0 : 1;
189 			data->pwm_enable[i] =
190 			    ((pwmcfg >> W83L786NG_PWM_ENABLE_SHIFT[i]) & 3) + 1;
191 			data->pwm[i] =
192 			    (w83l786ng_read_value(client, W83L786NG_REG_PWM[i])
193 			     & 0x0f) * 0x11;
194 		}
195 
196 
197 		/* Update the temperature sensors */
198 		for (i = 0; i < 2; i++) {
199 			for (j = 0; j < 3; j++) {
200 				data->temp[i][j] = w83l786ng_read_value(client,
201 				    W83L786NG_REG_TEMP[i][j]);
202 			}
203 		}
204 
205 		/* Update Smart Fan I/II tolerance */
206 		reg_tmp = w83l786ng_read_value(client, W83L786NG_REG_TOLERANCE);
207 		data->tolerance[0] = reg_tmp & 0x0f;
208 		data->tolerance[1] = (reg_tmp >> 4) & 0x0f;
209 
210 		data->last_updated = jiffies;
211 		data->valid = true;
212 
213 	}
214 
215 	mutex_unlock(&data->update_lock);
216 
217 	return data;
218 }
219 
220 /* following are the sysfs callback functions */
221 #define show_in_reg(reg) \
222 static ssize_t \
223 show_##reg(struct device *dev, struct device_attribute *attr, \
224 	   char *buf) \
225 { \
226 	int nr = to_sensor_dev_attr(attr)->index; \
227 	struct w83l786ng_data *data = w83l786ng_update_device(dev); \
228 	return sprintf(buf, "%d\n", IN_FROM_REG(data->reg[nr])); \
229 }
230 
231 show_in_reg(in)
232 show_in_reg(in_min)
233 show_in_reg(in_max)
234 
235 #define store_in_reg(REG, reg) \
236 static ssize_t \
237 store_in_##reg(struct device *dev, struct device_attribute *attr, \
238 	       const char *buf, size_t count) \
239 { \
240 	int nr = to_sensor_dev_attr(attr)->index; \
241 	struct w83l786ng_data *data = dev_get_drvdata(dev); \
242 	struct i2c_client *client = data->client; \
243 	unsigned long val; \
244 	int err = kstrtoul(buf, 10, &val); \
245 	if (err) \
246 		return err; \
247 	mutex_lock(&data->update_lock); \
248 	data->in_##reg[nr] = IN_TO_REG(val); \
249 	w83l786ng_write_value(client, W83L786NG_REG_IN_##REG(nr), \
250 			      data->in_##reg[nr]); \
251 	mutex_unlock(&data->update_lock); \
252 	return count; \
253 }
254 
255 store_in_reg(MIN, min)
256 store_in_reg(MAX, max)
257 
258 static struct sensor_device_attribute sda_in_input[] = {
259 	SENSOR_ATTR(in0_input, S_IRUGO, show_in, NULL, 0),
260 	SENSOR_ATTR(in1_input, S_IRUGO, show_in, NULL, 1),
261 	SENSOR_ATTR(in2_input, S_IRUGO, show_in, NULL, 2),
262 };
263 
264 static struct sensor_device_attribute sda_in_min[] = {
265 	SENSOR_ATTR(in0_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 0),
266 	SENSOR_ATTR(in1_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 1),
267 	SENSOR_ATTR(in2_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 2),
268 };
269 
270 static struct sensor_device_attribute sda_in_max[] = {
271 	SENSOR_ATTR(in0_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 0),
272 	SENSOR_ATTR(in1_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 1),
273 	SENSOR_ATTR(in2_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 2),
274 };
275 
276 #define show_fan_reg(reg) \
277 static ssize_t show_##reg(struct device *dev, struct device_attribute *attr, \
278 			  char *buf) \
279 { \
280 	int nr = to_sensor_dev_attr(attr)->index; \
281 	struct w83l786ng_data *data = w83l786ng_update_device(dev); \
282 	return sprintf(buf, "%d\n", \
283 		FAN_FROM_REG(data->reg[nr], DIV_FROM_REG(data->fan_div[nr]))); \
284 }
285 
286 show_fan_reg(fan);
287 show_fan_reg(fan_min);
288 
289 static ssize_t
290 store_fan_min(struct device *dev, struct device_attribute *attr,
291 	      const char *buf, size_t count)
292 {
293 	int nr = to_sensor_dev_attr(attr)->index;
294 	struct w83l786ng_data *data = dev_get_drvdata(dev);
295 	struct i2c_client *client = data->client;
296 	unsigned long val;
297 	int err;
298 
299 	err = kstrtoul(buf, 10, &val);
300 	if (err)
301 		return err;
302 
303 	mutex_lock(&data->update_lock);
304 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
305 	w83l786ng_write_value(client, W83L786NG_REG_FAN_MIN(nr),
306 			      data->fan_min[nr]);
307 	mutex_unlock(&data->update_lock);
308 
309 	return count;
310 }
311 
312 static ssize_t
313 show_fan_div(struct device *dev, struct device_attribute *attr,
314 	     char *buf)
315 {
316 	int nr = to_sensor_dev_attr(attr)->index;
317 	struct w83l786ng_data *data = w83l786ng_update_device(dev);
318 	return sprintf(buf, "%u\n", DIV_FROM_REG(data->fan_div[nr]));
319 }
320 
321 /*
322  * Note: we save and restore the fan minimum here, because its value is
323  * determined in part by the fan divisor.  This follows the principle of
324  * least surprise; the user doesn't expect the fan minimum to change just
325  * because the divisor changed.
326  */
327 static ssize_t
328 store_fan_div(struct device *dev, struct device_attribute *attr,
329 	      const char *buf, size_t count)
330 {
331 	int nr = to_sensor_dev_attr(attr)->index;
332 	struct w83l786ng_data *data = dev_get_drvdata(dev);
333 	struct i2c_client *client = data->client;
334 
335 	unsigned long min;
336 	u8 tmp_fan_div;
337 	u8 fan_div_reg;
338 	u8 keep_mask = 0;
339 	u8 new_shift = 0;
340 
341 	unsigned long val;
342 	int err;
343 
344 	err = kstrtoul(buf, 10, &val);
345 	if (err)
346 		return err;
347 
348 	/* Save fan_min */
349 	mutex_lock(&data->update_lock);
350 	min = FAN_FROM_REG(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr]));
351 
352 	data->fan_div[nr] = DIV_TO_REG(val);
353 
354 	switch (nr) {
355 	case 0:
356 		keep_mask = 0xf8;
357 		new_shift = 0;
358 		break;
359 	case 1:
360 		keep_mask = 0x8f;
361 		new_shift = 4;
362 		break;
363 	}
364 
365 	fan_div_reg = w83l786ng_read_value(client, W83L786NG_REG_FAN_DIV)
366 					   & keep_mask;
367 
368 	tmp_fan_div = (data->fan_div[nr] << new_shift) & ~keep_mask;
369 
370 	w83l786ng_write_value(client, W83L786NG_REG_FAN_DIV,
371 			      fan_div_reg | tmp_fan_div);
372 
373 	/* Restore fan_min */
374 	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
375 	w83l786ng_write_value(client, W83L786NG_REG_FAN_MIN(nr),
376 			      data->fan_min[nr]);
377 	mutex_unlock(&data->update_lock);
378 
379 	return count;
380 }
381 
382 static struct sensor_device_attribute sda_fan_input[] = {
383 	SENSOR_ATTR(fan1_input, S_IRUGO, show_fan, NULL, 0),
384 	SENSOR_ATTR(fan2_input, S_IRUGO, show_fan, NULL, 1),
385 };
386 
387 static struct sensor_device_attribute sda_fan_min[] = {
388 	SENSOR_ATTR(fan1_min, S_IWUSR | S_IRUGO, show_fan_min,
389 		    store_fan_min, 0),
390 	SENSOR_ATTR(fan2_min, S_IWUSR | S_IRUGO, show_fan_min,
391 		    store_fan_min, 1),
392 };
393 
394 static struct sensor_device_attribute sda_fan_div[] = {
395 	SENSOR_ATTR(fan1_div, S_IWUSR | S_IRUGO, show_fan_div,
396 		    store_fan_div, 0),
397 	SENSOR_ATTR(fan2_div, S_IWUSR | S_IRUGO, show_fan_div,
398 		    store_fan_div, 1),
399 };
400 
401 
402 /* read/write the temperature, includes measured value and limits */
403 
404 static ssize_t
405 show_temp(struct device *dev, struct device_attribute *attr, char *buf)
406 {
407 	struct sensor_device_attribute_2 *sensor_attr =
408 	    to_sensor_dev_attr_2(attr);
409 	int nr = sensor_attr->nr;
410 	int index = sensor_attr->index;
411 	struct w83l786ng_data *data = w83l786ng_update_device(dev);
412 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[nr][index]));
413 }
414 
415 static ssize_t
416 store_temp(struct device *dev, struct device_attribute *attr,
417 	   const char *buf, size_t count)
418 {
419 	struct sensor_device_attribute_2 *sensor_attr =
420 	    to_sensor_dev_attr_2(attr);
421 	int nr = sensor_attr->nr;
422 	int index = sensor_attr->index;
423 	struct w83l786ng_data *data = dev_get_drvdata(dev);
424 	struct i2c_client *client = data->client;
425 	long val;
426 	int err;
427 
428 	err = kstrtol(buf, 10, &val);
429 	if (err)
430 		return err;
431 
432 	mutex_lock(&data->update_lock);
433 	data->temp[nr][index] = TEMP_TO_REG(val);
434 	w83l786ng_write_value(client, W83L786NG_REG_TEMP[nr][index],
435 			      data->temp[nr][index]);
436 	mutex_unlock(&data->update_lock);
437 
438 	return count;
439 }
440 
441 static struct sensor_device_attribute_2 sda_temp_input[] = {
442 	SENSOR_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0, 0),
443 	SENSOR_ATTR_2(temp2_input, S_IRUGO, show_temp, NULL, 1, 0),
444 };
445 
446 static struct sensor_device_attribute_2 sda_temp_max[] = {
447 	SENSOR_ATTR_2(temp1_max, S_IRUGO | S_IWUSR,
448 		      show_temp, store_temp, 0, 1),
449 	SENSOR_ATTR_2(temp2_max, S_IRUGO | S_IWUSR,
450 		      show_temp, store_temp, 1, 1),
451 };
452 
453 static struct sensor_device_attribute_2 sda_temp_max_hyst[] = {
454 	SENSOR_ATTR_2(temp1_max_hyst, S_IRUGO | S_IWUSR,
455 		      show_temp, store_temp, 0, 2),
456 	SENSOR_ATTR_2(temp2_max_hyst, S_IRUGO | S_IWUSR,
457 		      show_temp, store_temp, 1, 2),
458 };
459 
460 #define show_pwm_reg(reg) \
461 static ssize_t show_##reg(struct device *dev, struct device_attribute *attr, \
462 			  char *buf) \
463 { \
464 	struct w83l786ng_data *data = w83l786ng_update_device(dev); \
465 	int nr = to_sensor_dev_attr(attr)->index; \
466 	return sprintf(buf, "%d\n", data->reg[nr]); \
467 }
468 
469 show_pwm_reg(pwm_mode)
470 show_pwm_reg(pwm_enable)
471 show_pwm_reg(pwm)
472 
473 static ssize_t
474 store_pwm_mode(struct device *dev, struct device_attribute *attr,
475 	       const char *buf, size_t count)
476 {
477 	int nr = to_sensor_dev_attr(attr)->index;
478 	struct w83l786ng_data *data = dev_get_drvdata(dev);
479 	struct i2c_client *client = data->client;
480 	u8 reg;
481 	unsigned long val;
482 	int err;
483 
484 	err = kstrtoul(buf, 10, &val);
485 	if (err)
486 		return err;
487 
488 	if (val > 1)
489 		return -EINVAL;
490 	mutex_lock(&data->update_lock);
491 	data->pwm_mode[nr] = val;
492 	reg = w83l786ng_read_value(client, W83L786NG_REG_FAN_CFG);
493 	reg &= ~(1 << W83L786NG_PWM_MODE_SHIFT[nr]);
494 	if (!val)
495 		reg |= 1 << W83L786NG_PWM_MODE_SHIFT[nr];
496 	w83l786ng_write_value(client, W83L786NG_REG_FAN_CFG, reg);
497 	mutex_unlock(&data->update_lock);
498 	return count;
499 }
500 
501 static ssize_t
502 store_pwm(struct device *dev, struct device_attribute *attr,
503 	  const char *buf, size_t count)
504 {
505 	int nr = to_sensor_dev_attr(attr)->index;
506 	struct w83l786ng_data *data = dev_get_drvdata(dev);
507 	struct i2c_client *client = data->client;
508 	unsigned long val;
509 	int err;
510 
511 	err = kstrtoul(buf, 10, &val);
512 	if (err)
513 		return err;
514 	val = clamp_val(val, 0, 255);
515 	val = DIV_ROUND_CLOSEST(val, 0x11);
516 
517 	mutex_lock(&data->update_lock);
518 	data->pwm[nr] = val * 0x11;
519 	val |= w83l786ng_read_value(client, W83L786NG_REG_PWM[nr]) & 0xf0;
520 	w83l786ng_write_value(client, W83L786NG_REG_PWM[nr], val);
521 	mutex_unlock(&data->update_lock);
522 	return count;
523 }
524 
525 static ssize_t
526 store_pwm_enable(struct device *dev, struct device_attribute *attr,
527 		 const char *buf, size_t count)
528 {
529 	int nr = to_sensor_dev_attr(attr)->index;
530 	struct w83l786ng_data *data = dev_get_drvdata(dev);
531 	struct i2c_client *client = data->client;
532 	u8 reg;
533 	unsigned long val;
534 	int err;
535 
536 	err = kstrtoul(buf, 10, &val);
537 	if (err)
538 		return err;
539 
540 	if (!val || val > 2)  /* only modes 1 and 2 are supported */
541 		return -EINVAL;
542 
543 	mutex_lock(&data->update_lock);
544 	reg = w83l786ng_read_value(client, W83L786NG_REG_FAN_CFG);
545 	data->pwm_enable[nr] = val;
546 	reg &= ~(0x03 << W83L786NG_PWM_ENABLE_SHIFT[nr]);
547 	reg |= (val - 1) << W83L786NG_PWM_ENABLE_SHIFT[nr];
548 	w83l786ng_write_value(client, W83L786NG_REG_FAN_CFG, reg);
549 	mutex_unlock(&data->update_lock);
550 	return count;
551 }
552 
553 static struct sensor_device_attribute sda_pwm[] = {
554 	SENSOR_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 0),
555 	SENSOR_ATTR(pwm2, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 1),
556 };
557 
558 static struct sensor_device_attribute sda_pwm_mode[] = {
559 	SENSOR_ATTR(pwm1_mode, S_IWUSR | S_IRUGO, show_pwm_mode,
560 		    store_pwm_mode, 0),
561 	SENSOR_ATTR(pwm2_mode, S_IWUSR | S_IRUGO, show_pwm_mode,
562 		    store_pwm_mode, 1),
563 };
564 
565 static struct sensor_device_attribute sda_pwm_enable[] = {
566 	SENSOR_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, show_pwm_enable,
567 		    store_pwm_enable, 0),
568 	SENSOR_ATTR(pwm2_enable, S_IWUSR | S_IRUGO, show_pwm_enable,
569 		    store_pwm_enable, 1),
570 };
571 
572 /* For Smart Fan I/Thermal Cruise and Smart Fan II */
573 static ssize_t
574 show_tolerance(struct device *dev, struct device_attribute *attr, char *buf)
575 {
576 	int nr = to_sensor_dev_attr(attr)->index;
577 	struct w83l786ng_data *data = w83l786ng_update_device(dev);
578 	return sprintf(buf, "%ld\n", (long)data->tolerance[nr]);
579 }
580 
581 static ssize_t
582 store_tolerance(struct device *dev, struct device_attribute *attr,
583 		const char *buf, size_t count)
584 {
585 	int nr = to_sensor_dev_attr(attr)->index;
586 	struct w83l786ng_data *data = dev_get_drvdata(dev);
587 	struct i2c_client *client = data->client;
588 	u8 tol_tmp, tol_mask;
589 	unsigned long val;
590 	int err;
591 
592 	err = kstrtoul(buf, 10, &val);
593 	if (err)
594 		return err;
595 
596 	mutex_lock(&data->update_lock);
597 	tol_mask = w83l786ng_read_value(client,
598 	    W83L786NG_REG_TOLERANCE) & ((nr == 1) ? 0x0f : 0xf0);
599 	tol_tmp = clamp_val(val, 0, 15);
600 	tol_tmp &= 0x0f;
601 	data->tolerance[nr] = tol_tmp;
602 	if (nr == 1)
603 		tol_tmp <<= 4;
604 
605 	w83l786ng_write_value(client, W83L786NG_REG_TOLERANCE,
606 			      tol_mask | tol_tmp);
607 	mutex_unlock(&data->update_lock);
608 	return count;
609 }
610 
611 static struct sensor_device_attribute sda_tolerance[] = {
612 	SENSOR_ATTR(pwm1_tolerance, S_IWUSR | S_IRUGO,
613 		    show_tolerance, store_tolerance, 0),
614 	SENSOR_ATTR(pwm2_tolerance, S_IWUSR | S_IRUGO,
615 		    show_tolerance, store_tolerance, 1),
616 };
617 
618 
619 #define IN_UNIT_ATTRS(X)	\
620 	&sda_in_input[X].dev_attr.attr,		\
621 	&sda_in_min[X].dev_attr.attr,		\
622 	&sda_in_max[X].dev_attr.attr
623 
624 #define FAN_UNIT_ATTRS(X)	\
625 	&sda_fan_input[X].dev_attr.attr,	\
626 	&sda_fan_min[X].dev_attr.attr,		\
627 	&sda_fan_div[X].dev_attr.attr
628 
629 #define TEMP_UNIT_ATTRS(X)	\
630 	&sda_temp_input[X].dev_attr.attr,	\
631 	&sda_temp_max[X].dev_attr.attr,		\
632 	&sda_temp_max_hyst[X].dev_attr.attr
633 
634 #define PWM_UNIT_ATTRS(X)	\
635 	&sda_pwm[X].dev_attr.attr,		\
636 	&sda_pwm_mode[X].dev_attr.attr,		\
637 	&sda_pwm_enable[X].dev_attr.attr
638 
639 #define TOLERANCE_UNIT_ATTRS(X)	\
640 	&sda_tolerance[X].dev_attr.attr
641 
642 static struct attribute *w83l786ng_attrs[] = {
643 	IN_UNIT_ATTRS(0),
644 	IN_UNIT_ATTRS(1),
645 	IN_UNIT_ATTRS(2),
646 	FAN_UNIT_ATTRS(0),
647 	FAN_UNIT_ATTRS(1),
648 	TEMP_UNIT_ATTRS(0),
649 	TEMP_UNIT_ATTRS(1),
650 	PWM_UNIT_ATTRS(0),
651 	PWM_UNIT_ATTRS(1),
652 	TOLERANCE_UNIT_ATTRS(0),
653 	TOLERANCE_UNIT_ATTRS(1),
654 	NULL
655 };
656 
657 ATTRIBUTE_GROUPS(w83l786ng);
658 
659 static int
660 w83l786ng_detect(struct i2c_client *client, struct i2c_board_info *info)
661 {
662 	struct i2c_adapter *adapter = client->adapter;
663 	u16 man_id;
664 	u8 chip_id;
665 
666 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
667 		return -ENODEV;
668 
669 	/* Detection */
670 	if ((w83l786ng_read_value(client, W83L786NG_REG_CONFIG) & 0x80)) {
671 		dev_dbg(&adapter->dev, "W83L786NG detection failed at 0x%02x\n",
672 			client->addr);
673 		return -ENODEV;
674 	}
675 
676 	/* Identification */
677 	man_id = (w83l786ng_read_value(client, W83L786NG_REG_MAN_ID1) << 8) +
678 		 w83l786ng_read_value(client, W83L786NG_REG_MAN_ID2);
679 	chip_id = w83l786ng_read_value(client, W83L786NG_REG_CHIP_ID);
680 
681 	if (man_id != 0x5CA3 ||		/* Winbond */
682 	    chip_id != 0x80) {		/* W83L786NG */
683 		dev_dbg(&adapter->dev,
684 			"Unsupported chip (man_id=0x%04X, chip_id=0x%02X)\n",
685 			man_id, chip_id);
686 		return -ENODEV;
687 	}
688 
689 	strscpy(info->type, "w83l786ng", I2C_NAME_SIZE);
690 
691 	return 0;
692 }
693 
694 static void w83l786ng_init_client(struct i2c_client *client)
695 {
696 	u8 tmp;
697 
698 	if (reset)
699 		w83l786ng_write_value(client, W83L786NG_REG_CONFIG, 0x80);
700 
701 	/* Start monitoring */
702 	tmp = w83l786ng_read_value(client, W83L786NG_REG_CONFIG);
703 	if (!(tmp & 0x01))
704 		w83l786ng_write_value(client, W83L786NG_REG_CONFIG, tmp | 0x01);
705 }
706 
707 static int
708 w83l786ng_probe(struct i2c_client *client)
709 {
710 	struct device *dev = &client->dev;
711 	struct w83l786ng_data *data;
712 	struct device *hwmon_dev;
713 	int i;
714 	u8 reg_tmp;
715 
716 	data = devm_kzalloc(dev, sizeof(struct w83l786ng_data), GFP_KERNEL);
717 	if (!data)
718 		return -ENOMEM;
719 
720 	data->client = client;
721 	mutex_init(&data->update_lock);
722 
723 	/* Initialize the chip */
724 	w83l786ng_init_client(client);
725 
726 	/* A few vars need to be filled upon startup */
727 	for (i = 0; i < 2; i++) {
728 		data->fan_min[i] = w83l786ng_read_value(client,
729 		    W83L786NG_REG_FAN_MIN(i));
730 	}
731 
732 	/* Update the fan divisor */
733 	reg_tmp = w83l786ng_read_value(client, W83L786NG_REG_FAN_DIV);
734 	data->fan_div[0] = reg_tmp & 0x07;
735 	data->fan_div[1] = (reg_tmp >> 4) & 0x07;
736 
737 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
738 							   data,
739 							   w83l786ng_groups);
740 	return PTR_ERR_OR_ZERO(hwmon_dev);
741 }
742 
743 static const struct i2c_device_id w83l786ng_id[] = {
744 	{ "w83l786ng", 0 },
745 	{ }
746 };
747 MODULE_DEVICE_TABLE(i2c, w83l786ng_id);
748 
749 static struct i2c_driver w83l786ng_driver = {
750 	.class		= I2C_CLASS_HWMON,
751 	.driver = {
752 		   .name = "w83l786ng",
753 	},
754 	.probe		= w83l786ng_probe,
755 	.id_table	= w83l786ng_id,
756 	.detect		= w83l786ng_detect,
757 	.address_list	= normal_i2c,
758 };
759 
760 module_i2c_driver(w83l786ng_driver);
761 
762 MODULE_AUTHOR("Kevin Lo");
763 MODULE_DESCRIPTION("w83l786ng driver");
764 MODULE_LICENSE("GPL");
765