xref: /openbmc/linux/drivers/hwmon/lm80.c (revision a09d2831)
1 /*
2  * lm80.c - From lm_sensors, Linux kernel modules for hardware
3  * monitoring
4  * Copyright (C) 1998, 1999  Frodo Looijaard <frodol@dds.nl>
5  * and Philip Edelbrock <phil@netroedge.com>
6  *
7  * Ported to Linux 2.6 by Tiago Sousa <mirage@kaotik.org>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22  */
23 
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/jiffies.h>
28 #include <linux/i2c.h>
29 #include <linux/hwmon.h>
30 #include <linux/hwmon-sysfs.h>
31 #include <linux/err.h>
32 #include <linux/mutex.h>
33 
34 /* Addresses to scan */
35 static const unsigned short normal_i2c[] = { 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d,
36 						0x2e, 0x2f, I2C_CLIENT_END };
37 
38 /* Many LM80 constants specified below */
39 
40 /* The LM80 registers */
41 #define LM80_REG_IN_MAX(nr)		(0x2a + (nr) * 2)
42 #define LM80_REG_IN_MIN(nr)		(0x2b + (nr) * 2)
43 #define LM80_REG_IN(nr)			(0x20 + (nr))
44 
45 #define LM80_REG_FAN1			0x28
46 #define LM80_REG_FAN2			0x29
47 #define LM80_REG_FAN_MIN(nr)		(0x3b + (nr))
48 
49 #define LM80_REG_TEMP			0x27
50 #define LM80_REG_TEMP_HOT_MAX		0x38
51 #define LM80_REG_TEMP_HOT_HYST		0x39
52 #define LM80_REG_TEMP_OS_MAX		0x3a
53 #define LM80_REG_TEMP_OS_HYST		0x3b
54 
55 #define LM80_REG_CONFIG			0x00
56 #define LM80_REG_ALARM1			0x01
57 #define LM80_REG_ALARM2			0x02
58 #define LM80_REG_MASK1			0x03
59 #define LM80_REG_MASK2			0x04
60 #define LM80_REG_FANDIV			0x05
61 #define LM80_REG_RES			0x06
62 
63 
64 /* Conversions. Rounding and limit checking is only done on the TO_REG
65    variants. Note that you should be a bit careful with which arguments
66    these macros are called: arguments may be evaluated more than once.
67    Fixing this is just not worth it. */
68 
69 #define IN_TO_REG(val)		(SENSORS_LIMIT(((val)+5)/10,0,255))
70 #define IN_FROM_REG(val)	((val)*10)
71 
72 static inline unsigned char FAN_TO_REG(unsigned rpm, unsigned div)
73 {
74 	if (rpm == 0)
75 		return 255;
76 	rpm = SENSORS_LIMIT(rpm, 1, 1000000);
77 	return SENSORS_LIMIT((1350000 + rpm*div / 2) / (rpm*div), 1, 254);
78 }
79 
80 #define FAN_FROM_REG(val,div)	((val)==0?-1:\
81 				(val)==255?0:1350000/((div)*(val)))
82 
83 static inline long TEMP_FROM_REG(u16 temp)
84 {
85 	long res;
86 
87 	temp >>= 4;
88 	if (temp < 0x0800)
89 		res = 625 * (long) temp;
90 	else
91 		res = ((long) temp - 0x01000) * 625;
92 
93 	return res / 10;
94 }
95 
96 #define TEMP_LIMIT_FROM_REG(val)	(((val)>0x80?(val)-0x100:(val))*1000)
97 
98 #define TEMP_LIMIT_TO_REG(val)		SENSORS_LIMIT((val)<0?\
99 					((val)-500)/1000:((val)+500)/1000,0,255)
100 
101 #define DIV_FROM_REG(val)		(1 << (val))
102 
103 /*
104  * Client data (each client gets its own)
105  */
106 
107 struct lm80_data {
108 	struct device *hwmon_dev;
109 	struct mutex update_lock;
110 	char valid;		/* !=0 if following fields are valid */
111 	unsigned long last_updated;	/* In jiffies */
112 
113 	u8 in[7];		/* Register value */
114 	u8 in_max[7];		/* Register value */
115 	u8 in_min[7];		/* Register value */
116 	u8 fan[2];		/* Register value */
117 	u8 fan_min[2];		/* Register value */
118 	u8 fan_div[2];		/* Register encoding, shifted right */
119 	u16 temp;		/* Register values, shifted right */
120 	u8 temp_hot_max;	/* Register value */
121 	u8 temp_hot_hyst;	/* Register value */
122 	u8 temp_os_max;		/* Register value */
123 	u8 temp_os_hyst;	/* Register value */
124 	u16 alarms;		/* Register encoding, combined */
125 };
126 
127 /*
128  * Functions declaration
129  */
130 
131 static int lm80_probe(struct i2c_client *client,
132 		      const struct i2c_device_id *id);
133 static int lm80_detect(struct i2c_client *client, struct i2c_board_info *info);
134 static void lm80_init_client(struct i2c_client *client);
135 static int lm80_remove(struct i2c_client *client);
136 static struct lm80_data *lm80_update_device(struct device *dev);
137 static int lm80_read_value(struct i2c_client *client, u8 reg);
138 static int lm80_write_value(struct i2c_client *client, u8 reg, u8 value);
139 
140 /*
141  * Driver data (common to all clients)
142  */
143 
144 static const struct i2c_device_id lm80_id[] = {
145 	{ "lm80", 0 },
146 	{ }
147 };
148 MODULE_DEVICE_TABLE(i2c, lm80_id);
149 
150 static struct i2c_driver lm80_driver = {
151 	.class		= I2C_CLASS_HWMON,
152 	.driver = {
153 		.name	= "lm80",
154 	},
155 	.probe		= lm80_probe,
156 	.remove		= lm80_remove,
157 	.id_table	= lm80_id,
158 	.detect		= lm80_detect,
159 	.address_list	= normal_i2c,
160 };
161 
162 /*
163  * Sysfs stuff
164  */
165 
166 #define show_in(suffix, value) \
167 static ssize_t show_in_##suffix(struct device *dev, struct device_attribute *attr, char *buf) \
168 { \
169 	int nr = to_sensor_dev_attr(attr)->index; \
170 	struct lm80_data *data = lm80_update_device(dev); \
171 	return sprintf(buf, "%d\n", IN_FROM_REG(data->value[nr])); \
172 }
173 show_in(min, in_min)
174 show_in(max, in_max)
175 show_in(input, in)
176 
177 #define set_in(suffix, value, reg) \
178 static ssize_t set_in_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \
179 	size_t count) \
180 { \
181 	int nr = to_sensor_dev_attr(attr)->index; \
182 	struct i2c_client *client = to_i2c_client(dev); \
183 	struct lm80_data *data = i2c_get_clientdata(client); \
184 	long val = simple_strtol(buf, NULL, 10); \
185  \
186 	mutex_lock(&data->update_lock);\
187 	data->value[nr] = IN_TO_REG(val); \
188 	lm80_write_value(client, reg(nr), data->value[nr]); \
189 	mutex_unlock(&data->update_lock);\
190 	return count; \
191 }
192 set_in(min, in_min, LM80_REG_IN_MIN)
193 set_in(max, in_max, LM80_REG_IN_MAX)
194 
195 #define show_fan(suffix, value) \
196 static ssize_t show_fan_##suffix(struct device *dev, struct device_attribute *attr, char *buf) \
197 { \
198 	int nr = to_sensor_dev_attr(attr)->index; \
199 	struct lm80_data *data = lm80_update_device(dev); \
200 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->value[nr], \
201 		       DIV_FROM_REG(data->fan_div[nr]))); \
202 }
203 show_fan(min, fan_min)
204 show_fan(input, fan)
205 
206 static ssize_t show_fan_div(struct device *dev, struct device_attribute *attr,
207 	char *buf)
208 {
209 	int nr = to_sensor_dev_attr(attr)->index;
210 	struct lm80_data *data = lm80_update_device(dev);
211 	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]));
212 }
213 
214 static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr,
215 	const char *buf, size_t count)
216 {
217 	int nr = to_sensor_dev_attr(attr)->index;
218 	struct i2c_client *client = to_i2c_client(dev);
219 	struct lm80_data *data = i2c_get_clientdata(client);
220 	long val = simple_strtoul(buf, NULL, 10);
221 
222 	mutex_lock(&data->update_lock);
223 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
224 	lm80_write_value(client, LM80_REG_FAN_MIN(nr + 1), data->fan_min[nr]);
225 	mutex_unlock(&data->update_lock);
226 	return count;
227 }
228 
229 /* Note: we save and restore the fan minimum here, because its value is
230    determined in part by the fan divisor.  This follows the principle of
231    least surprise; the user doesn't expect the fan minimum to change just
232    because the divisor changed. */
233 static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
234 	const char *buf, size_t count)
235 {
236 	int nr = to_sensor_dev_attr(attr)->index;
237 	struct i2c_client *client = to_i2c_client(dev);
238 	struct lm80_data *data = i2c_get_clientdata(client);
239 	unsigned long min, val = simple_strtoul(buf, NULL, 10);
240 	u8 reg;
241 
242 	/* Save fan_min */
243 	mutex_lock(&data->update_lock);
244 	min = FAN_FROM_REG(data->fan_min[nr],
245 			   DIV_FROM_REG(data->fan_div[nr]));
246 
247 	switch (val) {
248 	case 1: data->fan_div[nr] = 0; break;
249 	case 2: data->fan_div[nr] = 1; break;
250 	case 4: data->fan_div[nr] = 2; break;
251 	case 8: data->fan_div[nr] = 3; break;
252 	default:
253 		dev_err(&client->dev, "fan_div value %ld not "
254 			"supported. Choose one of 1, 2, 4 or 8!\n", val);
255 		mutex_unlock(&data->update_lock);
256 		return -EINVAL;
257 	}
258 
259 	reg = (lm80_read_value(client, LM80_REG_FANDIV) & ~(3 << (2 * (nr + 1))))
260 	    | (data->fan_div[nr] << (2 * (nr + 1)));
261 	lm80_write_value(client, LM80_REG_FANDIV, reg);
262 
263 	/* Restore fan_min */
264 	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
265 	lm80_write_value(client, LM80_REG_FAN_MIN(nr + 1), data->fan_min[nr]);
266 	mutex_unlock(&data->update_lock);
267 
268 	return count;
269 }
270 
271 static ssize_t show_temp_input1(struct device *dev, struct device_attribute *attr, char *buf)
272 {
273 	struct lm80_data *data = lm80_update_device(dev);
274 	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp));
275 }
276 
277 #define show_temp(suffix, value) \
278 static ssize_t show_temp_##suffix(struct device *dev, struct device_attribute *attr, char *buf) \
279 { \
280 	struct lm80_data *data = lm80_update_device(dev); \
281 	return sprintf(buf, "%d\n", TEMP_LIMIT_FROM_REG(data->value)); \
282 }
283 show_temp(hot_max, temp_hot_max);
284 show_temp(hot_hyst, temp_hot_hyst);
285 show_temp(os_max, temp_os_max);
286 show_temp(os_hyst, temp_os_hyst);
287 
288 #define set_temp(suffix, value, reg) \
289 static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \
290 	size_t count) \
291 { \
292 	struct i2c_client *client = to_i2c_client(dev); \
293 	struct lm80_data *data = i2c_get_clientdata(client); \
294 	long val = simple_strtoul(buf, NULL, 10); \
295  \
296 	mutex_lock(&data->update_lock); \
297 	data->value = TEMP_LIMIT_TO_REG(val); \
298 	lm80_write_value(client, reg, data->value); \
299 	mutex_unlock(&data->update_lock); \
300 	return count; \
301 }
302 set_temp(hot_max, temp_hot_max, LM80_REG_TEMP_HOT_MAX);
303 set_temp(hot_hyst, temp_hot_hyst, LM80_REG_TEMP_HOT_HYST);
304 set_temp(os_max, temp_os_max, LM80_REG_TEMP_OS_MAX);
305 set_temp(os_hyst, temp_os_hyst, LM80_REG_TEMP_OS_HYST);
306 
307 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
308 			   char *buf)
309 {
310 	struct lm80_data *data = lm80_update_device(dev);
311 	return sprintf(buf, "%u\n", data->alarms);
312 }
313 
314 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
315 			  char *buf)
316 {
317 	int bitnr = to_sensor_dev_attr(attr)->index;
318 	struct lm80_data *data = lm80_update_device(dev);
319 	return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
320 }
321 
322 static SENSOR_DEVICE_ATTR(in0_min, S_IWUSR | S_IRUGO,
323 		show_in_min, set_in_min, 0);
324 static SENSOR_DEVICE_ATTR(in1_min, S_IWUSR | S_IRUGO,
325 		show_in_min, set_in_min, 1);
326 static SENSOR_DEVICE_ATTR(in2_min, S_IWUSR | S_IRUGO,
327 		show_in_min, set_in_min, 2);
328 static SENSOR_DEVICE_ATTR(in3_min, S_IWUSR | S_IRUGO,
329 		show_in_min, set_in_min, 3);
330 static SENSOR_DEVICE_ATTR(in4_min, S_IWUSR | S_IRUGO,
331 		show_in_min, set_in_min, 4);
332 static SENSOR_DEVICE_ATTR(in5_min, S_IWUSR | S_IRUGO,
333 		show_in_min, set_in_min, 5);
334 static SENSOR_DEVICE_ATTR(in6_min, S_IWUSR | S_IRUGO,
335 		show_in_min, set_in_min, 6);
336 static SENSOR_DEVICE_ATTR(in0_max, S_IWUSR | S_IRUGO,
337 		show_in_max, set_in_max, 0);
338 static SENSOR_DEVICE_ATTR(in1_max, S_IWUSR | S_IRUGO,
339 		show_in_max, set_in_max, 1);
340 static SENSOR_DEVICE_ATTR(in2_max, S_IWUSR | S_IRUGO,
341 		show_in_max, set_in_max, 2);
342 static SENSOR_DEVICE_ATTR(in3_max, S_IWUSR | S_IRUGO,
343 		show_in_max, set_in_max, 3);
344 static SENSOR_DEVICE_ATTR(in4_max, S_IWUSR | S_IRUGO,
345 		show_in_max, set_in_max, 4);
346 static SENSOR_DEVICE_ATTR(in5_max, S_IWUSR | S_IRUGO,
347 		show_in_max, set_in_max, 5);
348 static SENSOR_DEVICE_ATTR(in6_max, S_IWUSR | S_IRUGO,
349 		show_in_max, set_in_max, 6);
350 static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, show_in_input, NULL, 0);
351 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_in_input, NULL, 1);
352 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_in_input, NULL, 2);
353 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_in_input, NULL, 3);
354 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_in_input, NULL, 4);
355 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, show_in_input, NULL, 5);
356 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, show_in_input, NULL, 6);
357 static SENSOR_DEVICE_ATTR(fan1_min, S_IWUSR | S_IRUGO,
358 		show_fan_min, set_fan_min, 0);
359 static SENSOR_DEVICE_ATTR(fan2_min, S_IWUSR | S_IRUGO,
360 		show_fan_min, set_fan_min, 1);
361 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan_input, NULL, 0);
362 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan_input, NULL, 1);
363 static SENSOR_DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO,
364 		show_fan_div, set_fan_div, 0);
365 static SENSOR_DEVICE_ATTR(fan2_div, S_IWUSR | S_IRUGO,
366 		show_fan_div, set_fan_div, 1);
367 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
368 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_hot_max,
369     set_temp_hot_max);
370 static DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_hot_hyst,
371     set_temp_hot_hyst);
372 static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp_os_max,
373     set_temp_os_max);
374 static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_os_hyst,
375     set_temp_os_hyst);
376 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
377 static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 0);
378 static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 1);
379 static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, show_alarm, NULL, 2);
380 static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, show_alarm, NULL, 3);
381 static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, show_alarm, NULL, 4);
382 static SENSOR_DEVICE_ATTR(in5_alarm, S_IRUGO, show_alarm, NULL, 5);
383 static SENSOR_DEVICE_ATTR(in6_alarm, S_IRUGO, show_alarm, NULL, 6);
384 static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_alarm, NULL, 10);
385 static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_alarm, NULL, 11);
386 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 8);
387 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 13);
388 
389 /*
390  * Real code
391  */
392 
393 static struct attribute *lm80_attributes[] = {
394 	&sensor_dev_attr_in0_min.dev_attr.attr,
395 	&sensor_dev_attr_in1_min.dev_attr.attr,
396 	&sensor_dev_attr_in2_min.dev_attr.attr,
397 	&sensor_dev_attr_in3_min.dev_attr.attr,
398 	&sensor_dev_attr_in4_min.dev_attr.attr,
399 	&sensor_dev_attr_in5_min.dev_attr.attr,
400 	&sensor_dev_attr_in6_min.dev_attr.attr,
401 	&sensor_dev_attr_in0_max.dev_attr.attr,
402 	&sensor_dev_attr_in1_max.dev_attr.attr,
403 	&sensor_dev_attr_in2_max.dev_attr.attr,
404 	&sensor_dev_attr_in3_max.dev_attr.attr,
405 	&sensor_dev_attr_in4_max.dev_attr.attr,
406 	&sensor_dev_attr_in5_max.dev_attr.attr,
407 	&sensor_dev_attr_in6_max.dev_attr.attr,
408 	&sensor_dev_attr_in0_input.dev_attr.attr,
409 	&sensor_dev_attr_in1_input.dev_attr.attr,
410 	&sensor_dev_attr_in2_input.dev_attr.attr,
411 	&sensor_dev_attr_in3_input.dev_attr.attr,
412 	&sensor_dev_attr_in4_input.dev_attr.attr,
413 	&sensor_dev_attr_in5_input.dev_attr.attr,
414 	&sensor_dev_attr_in6_input.dev_attr.attr,
415 	&sensor_dev_attr_fan1_min.dev_attr.attr,
416 	&sensor_dev_attr_fan2_min.dev_attr.attr,
417 	&sensor_dev_attr_fan1_input.dev_attr.attr,
418 	&sensor_dev_attr_fan2_input.dev_attr.attr,
419 	&sensor_dev_attr_fan1_div.dev_attr.attr,
420 	&sensor_dev_attr_fan2_div.dev_attr.attr,
421 	&dev_attr_temp1_input.attr,
422 	&dev_attr_temp1_max.attr,
423 	&dev_attr_temp1_max_hyst.attr,
424 	&dev_attr_temp1_crit.attr,
425 	&dev_attr_temp1_crit_hyst.attr,
426 	&dev_attr_alarms.attr,
427 	&sensor_dev_attr_in0_alarm.dev_attr.attr,
428 	&sensor_dev_attr_in1_alarm.dev_attr.attr,
429 	&sensor_dev_attr_in2_alarm.dev_attr.attr,
430 	&sensor_dev_attr_in3_alarm.dev_attr.attr,
431 	&sensor_dev_attr_in4_alarm.dev_attr.attr,
432 	&sensor_dev_attr_in5_alarm.dev_attr.attr,
433 	&sensor_dev_attr_in6_alarm.dev_attr.attr,
434 	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
435 	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
436 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
437 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
438 	NULL
439 };
440 
441 static const struct attribute_group lm80_group = {
442 	.attrs = lm80_attributes,
443 };
444 
445 /* Return 0 if detection is successful, -ENODEV otherwise */
446 static int lm80_detect(struct i2c_client *client, struct i2c_board_info *info)
447 {
448 	struct i2c_adapter *adapter = client->adapter;
449 	int i, cur;
450 
451 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
452 		return -ENODEV;
453 
454 	/* Now, we do the remaining detection. It is lousy. */
455 	if (lm80_read_value(client, LM80_REG_ALARM2) & 0xc0)
456 		return -ENODEV;
457 	for (i = 0x2a; i <= 0x3d; i++) {
458 		cur = i2c_smbus_read_byte_data(client, i);
459 		if ((i2c_smbus_read_byte_data(client, i + 0x40) != cur)
460 		 || (i2c_smbus_read_byte_data(client, i + 0x80) != cur)
461 		 || (i2c_smbus_read_byte_data(client, i + 0xc0) != cur))
462 		    return -ENODEV;
463 	}
464 
465 	strlcpy(info->type, "lm80", I2C_NAME_SIZE);
466 
467 	return 0;
468 }
469 
470 static int lm80_probe(struct i2c_client *client,
471 		      const struct i2c_device_id *id)
472 {
473 	struct lm80_data *data;
474 	int err;
475 
476 	data = kzalloc(sizeof(struct lm80_data), GFP_KERNEL);
477 	if (!data) {
478 		err = -ENOMEM;
479 		goto exit;
480 	}
481 
482 	i2c_set_clientdata(client, data);
483 	mutex_init(&data->update_lock);
484 
485 	/* Initialize the LM80 chip */
486 	lm80_init_client(client);
487 
488 	/* A few vars need to be filled upon startup */
489 	data->fan_min[0] = lm80_read_value(client, LM80_REG_FAN_MIN(1));
490 	data->fan_min[1] = lm80_read_value(client, LM80_REG_FAN_MIN(2));
491 
492 	/* Register sysfs hooks */
493 	if ((err = sysfs_create_group(&client->dev.kobj, &lm80_group)))
494 		goto error_free;
495 
496 	data->hwmon_dev = hwmon_device_register(&client->dev);
497 	if (IS_ERR(data->hwmon_dev)) {
498 		err = PTR_ERR(data->hwmon_dev);
499 		goto error_remove;
500 	}
501 
502 	return 0;
503 
504 error_remove:
505 	sysfs_remove_group(&client->dev.kobj, &lm80_group);
506 error_free:
507 	kfree(data);
508 exit:
509 	return err;
510 }
511 
512 static int lm80_remove(struct i2c_client *client)
513 {
514 	struct lm80_data *data = i2c_get_clientdata(client);
515 
516 	hwmon_device_unregister(data->hwmon_dev);
517 	sysfs_remove_group(&client->dev.kobj, &lm80_group);
518 
519 	kfree(data);
520 	return 0;
521 }
522 
523 static int lm80_read_value(struct i2c_client *client, u8 reg)
524 {
525 	return i2c_smbus_read_byte_data(client, reg);
526 }
527 
528 static int lm80_write_value(struct i2c_client *client, u8 reg, u8 value)
529 {
530 	return i2c_smbus_write_byte_data(client, reg, value);
531 }
532 
533 /* Called when we have found a new LM80. */
534 static void lm80_init_client(struct i2c_client *client)
535 {
536 	/* Reset all except Watchdog values and last conversion values
537 	   This sets fan-divs to 2, among others. This makes most other
538 	   initializations unnecessary */
539 	lm80_write_value(client, LM80_REG_CONFIG, 0x80);
540 	/* Set 11-bit temperature resolution */
541 	lm80_write_value(client, LM80_REG_RES, 0x08);
542 
543 	/* Start monitoring */
544 	lm80_write_value(client, LM80_REG_CONFIG, 0x01);
545 }
546 
547 static struct lm80_data *lm80_update_device(struct device *dev)
548 {
549 	struct i2c_client *client = to_i2c_client(dev);
550 	struct lm80_data *data = i2c_get_clientdata(client);
551 	int i;
552 
553 	mutex_lock(&data->update_lock);
554 
555 	if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
556 		dev_dbg(&client->dev, "Starting lm80 update\n");
557 		for (i = 0; i <= 6; i++) {
558 			data->in[i] =
559 			    lm80_read_value(client, LM80_REG_IN(i));
560 			data->in_min[i] =
561 			    lm80_read_value(client, LM80_REG_IN_MIN(i));
562 			data->in_max[i] =
563 			    lm80_read_value(client, LM80_REG_IN_MAX(i));
564 		}
565 		data->fan[0] = lm80_read_value(client, LM80_REG_FAN1);
566 		data->fan_min[0] =
567 		    lm80_read_value(client, LM80_REG_FAN_MIN(1));
568 		data->fan[1] = lm80_read_value(client, LM80_REG_FAN2);
569 		data->fan_min[1] =
570 		    lm80_read_value(client, LM80_REG_FAN_MIN(2));
571 
572 		data->temp =
573 		    (lm80_read_value(client, LM80_REG_TEMP) << 8) |
574 		    (lm80_read_value(client, LM80_REG_RES) & 0xf0);
575 		data->temp_os_max =
576 		    lm80_read_value(client, LM80_REG_TEMP_OS_MAX);
577 		data->temp_os_hyst =
578 		    lm80_read_value(client, LM80_REG_TEMP_OS_HYST);
579 		data->temp_hot_max =
580 		    lm80_read_value(client, LM80_REG_TEMP_HOT_MAX);
581 		data->temp_hot_hyst =
582 		    lm80_read_value(client, LM80_REG_TEMP_HOT_HYST);
583 
584 		i = lm80_read_value(client, LM80_REG_FANDIV);
585 		data->fan_div[0] = (i >> 2) & 0x03;
586 		data->fan_div[1] = (i >> 4) & 0x03;
587 		data->alarms = lm80_read_value(client, LM80_REG_ALARM1) +
588 		    (lm80_read_value(client, LM80_REG_ALARM2) << 8);
589 		data->last_updated = jiffies;
590 		data->valid = 1;
591 	}
592 
593 	mutex_unlock(&data->update_lock);
594 
595 	return data;
596 }
597 
598 static int __init sensors_lm80_init(void)
599 {
600 	return i2c_add_driver(&lm80_driver);
601 }
602 
603 static void __exit sensors_lm80_exit(void)
604 {
605 	i2c_del_driver(&lm80_driver);
606 }
607 
608 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
609 	"Philip Edelbrock <phil@netroedge.com>");
610 MODULE_DESCRIPTION("LM80 driver");
611 MODULE_LICENSE("GPL");
612 
613 module_init(sensors_lm80_init);
614 module_exit(sensors_lm80_exit);
615