xref: /openbmc/linux/drivers/hwmon/w83l786ng.c (revision 405db98b)
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-vid.h>
20 #include <linux/hwmon-sysfs.h>
21 #include <linux/err.h>
22 #include <linux/mutex.h>
23 #include <linux/jiffies.h>
24 
25 /* Addresses to scan */
26 static const unsigned short normal_i2c[] = { 0x2e, 0x2f, I2C_CLIENT_END };
27 
28 /* Insmod parameters */
29 
30 static bool reset;
31 module_param(reset, bool, 0);
32 MODULE_PARM_DESC(reset, "Set to 1 to reset chip, not recommended");
33 
34 #define W83L786NG_REG_IN_MIN(nr)	(0x2C + (nr) * 2)
35 #define W83L786NG_REG_IN_MAX(nr)	(0x2B + (nr) * 2)
36 #define W83L786NG_REG_IN(nr)		((nr) + 0x20)
37 
38 #define W83L786NG_REG_FAN(nr)		((nr) + 0x28)
39 #define W83L786NG_REG_FAN_MIN(nr)	((nr) + 0x3B)
40 
41 #define W83L786NG_REG_CONFIG		0x40
42 #define W83L786NG_REG_ALARM1		0x41
43 #define W83L786NG_REG_ALARM2		0x42
44 #define W83L786NG_REG_GPIO_EN		0x47
45 #define W83L786NG_REG_MAN_ID2		0x4C
46 #define W83L786NG_REG_MAN_ID1		0x4D
47 #define W83L786NG_REG_CHIP_ID		0x4E
48 
49 #define W83L786NG_REG_DIODE		0x53
50 #define W83L786NG_REG_FAN_DIV		0x54
51 #define W83L786NG_REG_FAN_CFG		0x80
52 
53 #define W83L786NG_REG_TOLERANCE		0x8D
54 
55 static const u8 W83L786NG_REG_TEMP[2][3] = {
56 	{ 0x25,		/* TEMP 0 in DataSheet */
57 	  0x35,		/* TEMP 0 Over in DataSheet */
58 	  0x36 },	/* TEMP 0 Hyst in DataSheet */
59 	{ 0x26,		/* TEMP 1 in DataSheet */
60 	  0x37,		/* TEMP 1 Over in DataSheet */
61 	  0x38 }	/* TEMP 1 Hyst in DataSheet */
62 };
63 
64 static const u8 W83L786NG_PWM_MODE_SHIFT[] = {6, 7};
65 static const u8 W83L786NG_PWM_ENABLE_SHIFT[] = {2, 4};
66 
67 /* FAN Duty Cycle, be used to control */
68 static const u8 W83L786NG_REG_PWM[] = {0x81, 0x87};
69 
70 
71 static inline u8
72 FAN_TO_REG(long rpm, int div)
73 {
74 	if (rpm == 0)
75 		return 255;
76 	rpm = clamp_val(rpm, 1, 1000000);
77 	return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
78 }
79 
80 #define FAN_FROM_REG(val, div)	((val) == 0   ? -1 : \
81 				((val) == 255 ? 0 : \
82 				1350000 / ((val) * (div))))
83 
84 /* for temp */
85 #define TEMP_TO_REG(val)	(clamp_val(((val) < 0 ? (val) + 0x100 * 1000 \
86 						      : (val)) / 1000, 0, 0xff))
87 #define TEMP_FROM_REG(val)	(((val) & 0x80 ? \
88 				  (val) - 0x100 : (val)) * 1000)
89 
90 /*
91  * The analog voltage inputs have 8mV LSB. Since the sysfs output is
92  * in mV as would be measured on the chip input pin, need to just
93  * multiply/divide by 8 to translate from/to register values.
94  */
95 #define IN_TO_REG(val)		(clamp_val((((val) + 4) / 8), 0, 255))
96 #define IN_FROM_REG(val)	((val) * 8)
97 
98 #define DIV_FROM_REG(val)	(1 << (val))
99 
100 static inline u8
101 DIV_TO_REG(long val)
102 {
103 	int i;
104 	val = clamp_val(val, 1, 128) >> 1;
105 	for (i = 0; i < 7; i++) {
106 		if (val == 0)
107 			break;
108 		val >>= 1;
109 	}
110 	return (u8)i;
111 }
112 
113 struct w83l786ng_data {
114 	struct i2c_client *client;
115 	struct mutex update_lock;
116 	bool valid;			/* true if following fields are valid */
117 	unsigned long last_updated;	/* In jiffies */
118 	unsigned long last_nonvolatile;	/* In jiffies, last time we update the
119 					 * nonvolatile registers */
120 
121 	u8 in[3];
122 	u8 in_max[3];
123 	u8 in_min[3];
124 	u8 fan[2];
125 	u8 fan_div[2];
126 	u8 fan_min[2];
127 	u8 temp_type[2];
128 	u8 temp[2][3];
129 	u8 pwm[2];
130 	u8 pwm_mode[2];	/* 0->DC variable voltage
131 			 * 1->PWM variable duty cycle */
132 
133 	u8 pwm_enable[2]; /* 1->manual
134 			   * 2->thermal cruise (also called SmartFan I) */
135 	u8 tolerance[2];
136 };
137 
138 static u8
139 w83l786ng_read_value(struct i2c_client *client, u8 reg)
140 {
141 	return i2c_smbus_read_byte_data(client, reg);
142 }
143 
144 static int
145 w83l786ng_write_value(struct i2c_client *client, u8 reg, u8 value)
146 {
147 	return i2c_smbus_write_byte_data(client, reg, value);
148 }
149 
150 static struct w83l786ng_data *w83l786ng_update_device(struct device *dev)
151 {
152 	struct w83l786ng_data *data = dev_get_drvdata(dev);
153 	struct i2c_client *client = data->client;
154 	int i, j;
155 	u8 reg_tmp, pwmcfg;
156 
157 	mutex_lock(&data->update_lock);
158 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
159 	    || !data->valid) {
160 		dev_dbg(&client->dev, "Updating w83l786ng data.\n");
161 
162 		/* Update the voltages measured value and limits */
163 		for (i = 0; i < 3; i++) {
164 			data->in[i] = w83l786ng_read_value(client,
165 			    W83L786NG_REG_IN(i));
166 			data->in_min[i] = w83l786ng_read_value(client,
167 			    W83L786NG_REG_IN_MIN(i));
168 			data->in_max[i] = w83l786ng_read_value(client,
169 			    W83L786NG_REG_IN_MAX(i));
170 		}
171 
172 		/* Update the fan counts and limits */
173 		for (i = 0; i < 2; i++) {
174 			data->fan[i] = w83l786ng_read_value(client,
175 			    W83L786NG_REG_FAN(i));
176 			data->fan_min[i] = w83l786ng_read_value(client,
177 			    W83L786NG_REG_FAN_MIN(i));
178 		}
179 
180 		/* Update the fan divisor */
181 		reg_tmp = w83l786ng_read_value(client, W83L786NG_REG_FAN_DIV);
182 		data->fan_div[0] = reg_tmp & 0x07;
183 		data->fan_div[1] = (reg_tmp >> 4) & 0x07;
184 
185 		pwmcfg = w83l786ng_read_value(client, W83L786NG_REG_FAN_CFG);
186 		for (i = 0; i < 2; i++) {
187 			data->pwm_mode[i] =
188 			    ((pwmcfg >> W83L786NG_PWM_MODE_SHIFT[i]) & 1)
189 			    ? 0 : 1;
190 			data->pwm_enable[i] =
191 			    ((pwmcfg >> W83L786NG_PWM_ENABLE_SHIFT[i]) & 3) + 1;
192 			data->pwm[i] =
193 			    (w83l786ng_read_value(client, W83L786NG_REG_PWM[i])
194 			     & 0x0f) * 0x11;
195 		}
196 
197 
198 		/* Update the temperature sensors */
199 		for (i = 0; i < 2; i++) {
200 			for (j = 0; j < 3; j++) {
201 				data->temp[i][j] = w83l786ng_read_value(client,
202 				    W83L786NG_REG_TEMP[i][j]);
203 			}
204 		}
205 
206 		/* Update Smart Fan I/II tolerance */
207 		reg_tmp = w83l786ng_read_value(client, W83L786NG_REG_TOLERANCE);
208 		data->tolerance[0] = reg_tmp & 0x0f;
209 		data->tolerance[1] = (reg_tmp >> 4) & 0x0f;
210 
211 		data->last_updated = jiffies;
212 		data->valid = true;
213 
214 	}
215 
216 	mutex_unlock(&data->update_lock);
217 
218 	return data;
219 }
220 
221 /* following are the sysfs callback functions */
222 #define show_in_reg(reg) \
223 static ssize_t \
224 show_##reg(struct device *dev, struct device_attribute *attr, \
225 	   char *buf) \
226 { \
227 	int nr = to_sensor_dev_attr(attr)->index; \
228 	struct w83l786ng_data *data = w83l786ng_update_device(dev); \
229 	return sprintf(buf, "%d\n", IN_FROM_REG(data->reg[nr])); \
230 }
231 
232 show_in_reg(in)
233 show_in_reg(in_min)
234 show_in_reg(in_max)
235 
236 #define store_in_reg(REG, reg) \
237 static ssize_t \
238 store_in_##reg(struct device *dev, struct device_attribute *attr, \
239 	       const char *buf, size_t count) \
240 { \
241 	int nr = to_sensor_dev_attr(attr)->index; \
242 	struct w83l786ng_data *data = dev_get_drvdata(dev); \
243 	struct i2c_client *client = data->client; \
244 	unsigned long val; \
245 	int err = kstrtoul(buf, 10, &val); \
246 	if (err) \
247 		return err; \
248 	mutex_lock(&data->update_lock); \
249 	data->in_##reg[nr] = IN_TO_REG(val); \
250 	w83l786ng_write_value(client, W83L786NG_REG_IN_##REG(nr), \
251 			      data->in_##reg[nr]); \
252 	mutex_unlock(&data->update_lock); \
253 	return count; \
254 }
255 
256 store_in_reg(MIN, min)
257 store_in_reg(MAX, max)
258 
259 static struct sensor_device_attribute sda_in_input[] = {
260 	SENSOR_ATTR(in0_input, S_IRUGO, show_in, NULL, 0),
261 	SENSOR_ATTR(in1_input, S_IRUGO, show_in, NULL, 1),
262 	SENSOR_ATTR(in2_input, S_IRUGO, show_in, NULL, 2),
263 };
264 
265 static struct sensor_device_attribute sda_in_min[] = {
266 	SENSOR_ATTR(in0_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 0),
267 	SENSOR_ATTR(in1_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 1),
268 	SENSOR_ATTR(in2_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 2),
269 };
270 
271 static struct sensor_device_attribute sda_in_max[] = {
272 	SENSOR_ATTR(in0_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 0),
273 	SENSOR_ATTR(in1_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 1),
274 	SENSOR_ATTR(in2_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 2),
275 };
276 
277 #define show_fan_reg(reg) \
278 static ssize_t show_##reg(struct device *dev, struct device_attribute *attr, \
279 			  char *buf) \
280 { \
281 	int nr = to_sensor_dev_attr(attr)->index; \
282 	struct w83l786ng_data *data = w83l786ng_update_device(dev); \
283 	return sprintf(buf, "%d\n", \
284 		FAN_FROM_REG(data->reg[nr], DIV_FROM_REG(data->fan_div[nr]))); \
285 }
286 
287 show_fan_reg(fan);
288 show_fan_reg(fan_min);
289 
290 static ssize_t
291 store_fan_min(struct device *dev, struct device_attribute *attr,
292 	      const char *buf, size_t count)
293 {
294 	int nr = to_sensor_dev_attr(attr)->index;
295 	struct w83l786ng_data *data = dev_get_drvdata(dev);
296 	struct i2c_client *client = data->client;
297 	unsigned long val;
298 	int err;
299 
300 	err = kstrtoul(buf, 10, &val);
301 	if (err)
302 		return err;
303 
304 	mutex_lock(&data->update_lock);
305 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
306 	w83l786ng_write_value(client, W83L786NG_REG_FAN_MIN(nr),
307 			      data->fan_min[nr]);
308 	mutex_unlock(&data->update_lock);
309 
310 	return count;
311 }
312 
313 static ssize_t
314 show_fan_div(struct device *dev, struct device_attribute *attr,
315 	     char *buf)
316 {
317 	int nr = to_sensor_dev_attr(attr)->index;
318 	struct w83l786ng_data *data = w83l786ng_update_device(dev);
319 	return sprintf(buf, "%u\n", DIV_FROM_REG(data->fan_div[nr]));
320 }
321 
322 /*
323  * Note: we save and restore the fan minimum here, because its value is
324  * determined in part by the fan divisor.  This follows the principle of
325  * least surprise; the user doesn't expect the fan minimum to change just
326  * because the divisor changed.
327  */
328 static ssize_t
329 store_fan_div(struct device *dev, struct device_attribute *attr,
330 	      const char *buf, size_t count)
331 {
332 	int nr = to_sensor_dev_attr(attr)->index;
333 	struct w83l786ng_data *data = dev_get_drvdata(dev);
334 	struct i2c_client *client = data->client;
335 
336 	unsigned long min;
337 	u8 tmp_fan_div;
338 	u8 fan_div_reg;
339 	u8 keep_mask = 0;
340 	u8 new_shift = 0;
341 
342 	unsigned long val;
343 	int err;
344 
345 	err = kstrtoul(buf, 10, &val);
346 	if (err)
347 		return err;
348 
349 	/* Save fan_min */
350 	mutex_lock(&data->update_lock);
351 	min = FAN_FROM_REG(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr]));
352 
353 	data->fan_div[nr] = DIV_TO_REG(val);
354 
355 	switch (nr) {
356 	case 0:
357 		keep_mask = 0xf8;
358 		new_shift = 0;
359 		break;
360 	case 1:
361 		keep_mask = 0x8f;
362 		new_shift = 4;
363 		break;
364 	}
365 
366 	fan_div_reg = w83l786ng_read_value(client, W83L786NG_REG_FAN_DIV)
367 					   & keep_mask;
368 
369 	tmp_fan_div = (data->fan_div[nr] << new_shift) & ~keep_mask;
370 
371 	w83l786ng_write_value(client, W83L786NG_REG_FAN_DIV,
372 			      fan_div_reg | tmp_fan_div);
373 
374 	/* Restore fan_min */
375 	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
376 	w83l786ng_write_value(client, W83L786NG_REG_FAN_MIN(nr),
377 			      data->fan_min[nr]);
378 	mutex_unlock(&data->update_lock);
379 
380 	return count;
381 }
382 
383 static struct sensor_device_attribute sda_fan_input[] = {
384 	SENSOR_ATTR(fan1_input, S_IRUGO, show_fan, NULL, 0),
385 	SENSOR_ATTR(fan2_input, S_IRUGO, show_fan, NULL, 1),
386 };
387 
388 static struct sensor_device_attribute sda_fan_min[] = {
389 	SENSOR_ATTR(fan1_min, S_IWUSR | S_IRUGO, show_fan_min,
390 		    store_fan_min, 0),
391 	SENSOR_ATTR(fan2_min, S_IWUSR | S_IRUGO, show_fan_min,
392 		    store_fan_min, 1),
393 };
394 
395 static struct sensor_device_attribute sda_fan_div[] = {
396 	SENSOR_ATTR(fan1_div, S_IWUSR | S_IRUGO, show_fan_div,
397 		    store_fan_div, 0),
398 	SENSOR_ATTR(fan2_div, S_IWUSR | S_IRUGO, show_fan_div,
399 		    store_fan_div, 1),
400 };
401 
402 
403 /* read/write the temperature, includes measured value and limits */
404 
405 static ssize_t
406 show_temp(struct device *dev, struct device_attribute *attr, char *buf)
407 {
408 	struct sensor_device_attribute_2 *sensor_attr =
409 	    to_sensor_dev_attr_2(attr);
410 	int nr = sensor_attr->nr;
411 	int index = sensor_attr->index;
412 	struct w83l786ng_data *data = w83l786ng_update_device(dev);
413 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[nr][index]));
414 }
415 
416 static ssize_t
417 store_temp(struct device *dev, struct device_attribute *attr,
418 	   const char *buf, size_t count)
419 {
420 	struct sensor_device_attribute_2 *sensor_attr =
421 	    to_sensor_dev_attr_2(attr);
422 	int nr = sensor_attr->nr;
423 	int index = sensor_attr->index;
424 	struct w83l786ng_data *data = dev_get_drvdata(dev);
425 	struct i2c_client *client = data->client;
426 	long val;
427 	int err;
428 
429 	err = kstrtol(buf, 10, &val);
430 	if (err)
431 		return err;
432 
433 	mutex_lock(&data->update_lock);
434 	data->temp[nr][index] = TEMP_TO_REG(val);
435 	w83l786ng_write_value(client, W83L786NG_REG_TEMP[nr][index],
436 			      data->temp[nr][index]);
437 	mutex_unlock(&data->update_lock);
438 
439 	return count;
440 }
441 
442 static struct sensor_device_attribute_2 sda_temp_input[] = {
443 	SENSOR_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0, 0),
444 	SENSOR_ATTR_2(temp2_input, S_IRUGO, show_temp, NULL, 1, 0),
445 };
446 
447 static struct sensor_device_attribute_2 sda_temp_max[] = {
448 	SENSOR_ATTR_2(temp1_max, S_IRUGO | S_IWUSR,
449 		      show_temp, store_temp, 0, 1),
450 	SENSOR_ATTR_2(temp2_max, S_IRUGO | S_IWUSR,
451 		      show_temp, store_temp, 1, 1),
452 };
453 
454 static struct sensor_device_attribute_2 sda_temp_max_hyst[] = {
455 	SENSOR_ATTR_2(temp1_max_hyst, S_IRUGO | S_IWUSR,
456 		      show_temp, store_temp, 0, 2),
457 	SENSOR_ATTR_2(temp2_max_hyst, S_IRUGO | S_IWUSR,
458 		      show_temp, store_temp, 1, 2),
459 };
460 
461 #define show_pwm_reg(reg) \
462 static ssize_t show_##reg(struct device *dev, struct device_attribute *attr, \
463 			  char *buf) \
464 { \
465 	struct w83l786ng_data *data = w83l786ng_update_device(dev); \
466 	int nr = to_sensor_dev_attr(attr)->index; \
467 	return sprintf(buf, "%d\n", data->reg[nr]); \
468 }
469 
470 show_pwm_reg(pwm_mode)
471 show_pwm_reg(pwm_enable)
472 show_pwm_reg(pwm)
473 
474 static ssize_t
475 store_pwm_mode(struct device *dev, struct device_attribute *attr,
476 	       const char *buf, size_t count)
477 {
478 	int nr = to_sensor_dev_attr(attr)->index;
479 	struct w83l786ng_data *data = dev_get_drvdata(dev);
480 	struct i2c_client *client = data->client;
481 	u8 reg;
482 	unsigned long val;
483 	int err;
484 
485 	err = kstrtoul(buf, 10, &val);
486 	if (err)
487 		return err;
488 
489 	if (val > 1)
490 		return -EINVAL;
491 	mutex_lock(&data->update_lock);
492 	data->pwm_mode[nr] = val;
493 	reg = w83l786ng_read_value(client, W83L786NG_REG_FAN_CFG);
494 	reg &= ~(1 << W83L786NG_PWM_MODE_SHIFT[nr]);
495 	if (!val)
496 		reg |= 1 << W83L786NG_PWM_MODE_SHIFT[nr];
497 	w83l786ng_write_value(client, W83L786NG_REG_FAN_CFG, reg);
498 	mutex_unlock(&data->update_lock);
499 	return count;
500 }
501 
502 static ssize_t
503 store_pwm(struct device *dev, struct device_attribute *attr,
504 	  const char *buf, size_t count)
505 {
506 	int nr = to_sensor_dev_attr(attr)->index;
507 	struct w83l786ng_data *data = dev_get_drvdata(dev);
508 	struct i2c_client *client = data->client;
509 	unsigned long val;
510 	int err;
511 
512 	err = kstrtoul(buf, 10, &val);
513 	if (err)
514 		return err;
515 	val = clamp_val(val, 0, 255);
516 	val = DIV_ROUND_CLOSEST(val, 0x11);
517 
518 	mutex_lock(&data->update_lock);
519 	data->pwm[nr] = val * 0x11;
520 	val |= w83l786ng_read_value(client, W83L786NG_REG_PWM[nr]) & 0xf0;
521 	w83l786ng_write_value(client, W83L786NG_REG_PWM[nr], val);
522 	mutex_unlock(&data->update_lock);
523 	return count;
524 }
525 
526 static ssize_t
527 store_pwm_enable(struct device *dev, struct device_attribute *attr,
528 		 const char *buf, size_t count)
529 {
530 	int nr = to_sensor_dev_attr(attr)->index;
531 	struct w83l786ng_data *data = dev_get_drvdata(dev);
532 	struct i2c_client *client = data->client;
533 	u8 reg;
534 	unsigned long val;
535 	int err;
536 
537 	err = kstrtoul(buf, 10, &val);
538 	if (err)
539 		return err;
540 
541 	if (!val || val > 2)  /* only modes 1 and 2 are supported */
542 		return -EINVAL;
543 
544 	mutex_lock(&data->update_lock);
545 	reg = w83l786ng_read_value(client, W83L786NG_REG_FAN_CFG);
546 	data->pwm_enable[nr] = val;
547 	reg &= ~(0x03 << W83L786NG_PWM_ENABLE_SHIFT[nr]);
548 	reg |= (val - 1) << W83L786NG_PWM_ENABLE_SHIFT[nr];
549 	w83l786ng_write_value(client, W83L786NG_REG_FAN_CFG, reg);
550 	mutex_unlock(&data->update_lock);
551 	return count;
552 }
553 
554 static struct sensor_device_attribute sda_pwm[] = {
555 	SENSOR_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 0),
556 	SENSOR_ATTR(pwm2, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 1),
557 };
558 
559 static struct sensor_device_attribute sda_pwm_mode[] = {
560 	SENSOR_ATTR(pwm1_mode, S_IWUSR | S_IRUGO, show_pwm_mode,
561 		    store_pwm_mode, 0),
562 	SENSOR_ATTR(pwm2_mode, S_IWUSR | S_IRUGO, show_pwm_mode,
563 		    store_pwm_mode, 1),
564 };
565 
566 static struct sensor_device_attribute sda_pwm_enable[] = {
567 	SENSOR_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, show_pwm_enable,
568 		    store_pwm_enable, 0),
569 	SENSOR_ATTR(pwm2_enable, S_IWUSR | S_IRUGO, show_pwm_enable,
570 		    store_pwm_enable, 1),
571 };
572 
573 /* For Smart Fan I/Thermal Cruise and Smart Fan II */
574 static ssize_t
575 show_tolerance(struct device *dev, struct device_attribute *attr, char *buf)
576 {
577 	int nr = to_sensor_dev_attr(attr)->index;
578 	struct w83l786ng_data *data = w83l786ng_update_device(dev);
579 	return sprintf(buf, "%ld\n", (long)data->tolerance[nr]);
580 }
581 
582 static ssize_t
583 store_tolerance(struct device *dev, struct device_attribute *attr,
584 		const char *buf, size_t count)
585 {
586 	int nr = to_sensor_dev_attr(attr)->index;
587 	struct w83l786ng_data *data = dev_get_drvdata(dev);
588 	struct i2c_client *client = data->client;
589 	u8 tol_tmp, tol_mask;
590 	unsigned long val;
591 	int err;
592 
593 	err = kstrtoul(buf, 10, &val);
594 	if (err)
595 		return err;
596 
597 	mutex_lock(&data->update_lock);
598 	tol_mask = w83l786ng_read_value(client,
599 	    W83L786NG_REG_TOLERANCE) & ((nr == 1) ? 0x0f : 0xf0);
600 	tol_tmp = clamp_val(val, 0, 15);
601 	tol_tmp &= 0x0f;
602 	data->tolerance[nr] = tol_tmp;
603 	if (nr == 1)
604 		tol_tmp <<= 4;
605 
606 	w83l786ng_write_value(client, W83L786NG_REG_TOLERANCE,
607 			      tol_mask | tol_tmp);
608 	mutex_unlock(&data->update_lock);
609 	return count;
610 }
611 
612 static struct sensor_device_attribute sda_tolerance[] = {
613 	SENSOR_ATTR(pwm1_tolerance, S_IWUSR | S_IRUGO,
614 		    show_tolerance, store_tolerance, 0),
615 	SENSOR_ATTR(pwm2_tolerance, S_IWUSR | S_IRUGO,
616 		    show_tolerance, store_tolerance, 1),
617 };
618 
619 
620 #define IN_UNIT_ATTRS(X)	\
621 	&sda_in_input[X].dev_attr.attr,		\
622 	&sda_in_min[X].dev_attr.attr,		\
623 	&sda_in_max[X].dev_attr.attr
624 
625 #define FAN_UNIT_ATTRS(X)	\
626 	&sda_fan_input[X].dev_attr.attr,	\
627 	&sda_fan_min[X].dev_attr.attr,		\
628 	&sda_fan_div[X].dev_attr.attr
629 
630 #define TEMP_UNIT_ATTRS(X)	\
631 	&sda_temp_input[X].dev_attr.attr,	\
632 	&sda_temp_max[X].dev_attr.attr,		\
633 	&sda_temp_max_hyst[X].dev_attr.attr
634 
635 #define PWM_UNIT_ATTRS(X)	\
636 	&sda_pwm[X].dev_attr.attr,		\
637 	&sda_pwm_mode[X].dev_attr.attr,		\
638 	&sda_pwm_enable[X].dev_attr.attr
639 
640 #define TOLERANCE_UNIT_ATTRS(X)	\
641 	&sda_tolerance[X].dev_attr.attr
642 
643 static struct attribute *w83l786ng_attrs[] = {
644 	IN_UNIT_ATTRS(0),
645 	IN_UNIT_ATTRS(1),
646 	IN_UNIT_ATTRS(2),
647 	FAN_UNIT_ATTRS(0),
648 	FAN_UNIT_ATTRS(1),
649 	TEMP_UNIT_ATTRS(0),
650 	TEMP_UNIT_ATTRS(1),
651 	PWM_UNIT_ATTRS(0),
652 	PWM_UNIT_ATTRS(1),
653 	TOLERANCE_UNIT_ATTRS(0),
654 	TOLERANCE_UNIT_ATTRS(1),
655 	NULL
656 };
657 
658 ATTRIBUTE_GROUPS(w83l786ng);
659 
660 static int
661 w83l786ng_detect(struct i2c_client *client, struct i2c_board_info *info)
662 {
663 	struct i2c_adapter *adapter = client->adapter;
664 	u16 man_id;
665 	u8 chip_id;
666 
667 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
668 		return -ENODEV;
669 
670 	/* Detection */
671 	if ((w83l786ng_read_value(client, W83L786NG_REG_CONFIG) & 0x80)) {
672 		dev_dbg(&adapter->dev, "W83L786NG detection failed at 0x%02x\n",
673 			client->addr);
674 		return -ENODEV;
675 	}
676 
677 	/* Identification */
678 	man_id = (w83l786ng_read_value(client, W83L786NG_REG_MAN_ID1) << 8) +
679 		 w83l786ng_read_value(client, W83L786NG_REG_MAN_ID2);
680 	chip_id = w83l786ng_read_value(client, W83L786NG_REG_CHIP_ID);
681 
682 	if (man_id != 0x5CA3 ||		/* Winbond */
683 	    chip_id != 0x80) {		/* W83L786NG */
684 		dev_dbg(&adapter->dev,
685 			"Unsupported chip (man_id=0x%04X, chip_id=0x%02X)\n",
686 			man_id, chip_id);
687 		return -ENODEV;
688 	}
689 
690 	strlcpy(info->type, "w83l786ng", I2C_NAME_SIZE);
691 
692 	return 0;
693 }
694 
695 static void w83l786ng_init_client(struct i2c_client *client)
696 {
697 	u8 tmp;
698 
699 	if (reset)
700 		w83l786ng_write_value(client, W83L786NG_REG_CONFIG, 0x80);
701 
702 	/* Start monitoring */
703 	tmp = w83l786ng_read_value(client, W83L786NG_REG_CONFIG);
704 	if (!(tmp & 0x01))
705 		w83l786ng_write_value(client, W83L786NG_REG_CONFIG, tmp | 0x01);
706 }
707 
708 static int
709 w83l786ng_probe(struct i2c_client *client)
710 {
711 	struct device *dev = &client->dev;
712 	struct w83l786ng_data *data;
713 	struct device *hwmon_dev;
714 	int i;
715 	u8 reg_tmp;
716 
717 	data = devm_kzalloc(dev, sizeof(struct w83l786ng_data), GFP_KERNEL);
718 	if (!data)
719 		return -ENOMEM;
720 
721 	data->client = client;
722 	mutex_init(&data->update_lock);
723 
724 	/* Initialize the chip */
725 	w83l786ng_init_client(client);
726 
727 	/* A few vars need to be filled upon startup */
728 	for (i = 0; i < 2; i++) {
729 		data->fan_min[i] = w83l786ng_read_value(client,
730 		    W83L786NG_REG_FAN_MIN(i));
731 	}
732 
733 	/* Update the fan divisor */
734 	reg_tmp = w83l786ng_read_value(client, W83L786NG_REG_FAN_DIV);
735 	data->fan_div[0] = reg_tmp & 0x07;
736 	data->fan_div[1] = (reg_tmp >> 4) & 0x07;
737 
738 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
739 							   data,
740 							   w83l786ng_groups);
741 	return PTR_ERR_OR_ZERO(hwmon_dev);
742 }
743 
744 static const struct i2c_device_id w83l786ng_id[] = {
745 	{ "w83l786ng", 0 },
746 	{ }
747 };
748 MODULE_DEVICE_TABLE(i2c, w83l786ng_id);
749 
750 static struct i2c_driver w83l786ng_driver = {
751 	.class		= I2C_CLASS_HWMON,
752 	.driver = {
753 		   .name = "w83l786ng",
754 	},
755 	.probe_new	= w83l786ng_probe,
756 	.id_table	= w83l786ng_id,
757 	.detect		= w83l786ng_detect,
758 	.address_list	= normal_i2c,
759 };
760 
761 module_i2c_driver(w83l786ng_driver);
762 
763 MODULE_AUTHOR("Kevin Lo");
764 MODULE_DESCRIPTION("w83l786ng driver");
765 MODULE_LICENSE("GPL");
766