xref: /openbmc/linux/drivers/hwmon/lm80.c (revision 93dc544c)
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 /* Insmod parameters */
39 I2C_CLIENT_INSMOD_1(lm80);
40 
41 /* Many LM80 constants specified below */
42 
43 /* The LM80 registers */
44 #define LM80_REG_IN_MAX(nr)		(0x2a + (nr) * 2)
45 #define LM80_REG_IN_MIN(nr)		(0x2b + (nr) * 2)
46 #define LM80_REG_IN(nr)			(0x20 + (nr))
47 
48 #define LM80_REG_FAN1			0x28
49 #define LM80_REG_FAN2			0x29
50 #define LM80_REG_FAN_MIN(nr)		(0x3b + (nr))
51 
52 #define LM80_REG_TEMP			0x27
53 #define LM80_REG_TEMP_HOT_MAX		0x38
54 #define LM80_REG_TEMP_HOT_HYST		0x39
55 #define LM80_REG_TEMP_OS_MAX		0x3a
56 #define LM80_REG_TEMP_OS_HYST		0x3b
57 
58 #define LM80_REG_CONFIG			0x00
59 #define LM80_REG_ALARM1			0x01
60 #define LM80_REG_ALARM2			0x02
61 #define LM80_REG_MASK1			0x03
62 #define LM80_REG_MASK2			0x04
63 #define LM80_REG_FANDIV			0x05
64 #define LM80_REG_RES			0x06
65 
66 
67 /* Conversions. Rounding and limit checking is only done on the TO_REG
68    variants. Note that you should be a bit careful with which arguments
69    these macros are called: arguments may be evaluated more than once.
70    Fixing this is just not worth it. */
71 
72 #define IN_TO_REG(val)		(SENSORS_LIMIT(((val)+5)/10,0,255))
73 #define IN_FROM_REG(val)	((val)*10)
74 
75 static inline unsigned char FAN_TO_REG(unsigned rpm, unsigned div)
76 {
77 	if (rpm == 0)
78 		return 255;
79 	rpm = SENSORS_LIMIT(rpm, 1, 1000000);
80 	return SENSORS_LIMIT((1350000 + rpm*div / 2) / (rpm*div), 1, 254);
81 }
82 
83 #define FAN_FROM_REG(val,div)	((val)==0?-1:\
84 				(val)==255?0:1350000/((div)*(val)))
85 
86 static inline long TEMP_FROM_REG(u16 temp)
87 {
88 	long res;
89 
90 	temp >>= 4;
91 	if (temp < 0x0800)
92 		res = 625 * (long) temp;
93 	else
94 		res = ((long) temp - 0x01000) * 625;
95 
96 	return res / 10;
97 }
98 
99 #define TEMP_LIMIT_FROM_REG(val)	(((val)>0x80?(val)-0x100:(val))*1000)
100 
101 #define TEMP_LIMIT_TO_REG(val)		SENSORS_LIMIT((val)<0?\
102 					((val)-500)/1000:((val)+500)/1000,0,255)
103 
104 #define DIV_FROM_REG(val)		(1 << (val))
105 
106 /*
107  * Client data (each client gets its own)
108  */
109 
110 struct lm80_data {
111 	struct device *hwmon_dev;
112 	struct mutex update_lock;
113 	char valid;		/* !=0 if following fields are valid */
114 	unsigned long last_updated;	/* In jiffies */
115 
116 	u8 in[7];		/* Register value */
117 	u8 in_max[7];		/* Register value */
118 	u8 in_min[7];		/* Register value */
119 	u8 fan[2];		/* Register value */
120 	u8 fan_min[2];		/* Register value */
121 	u8 fan_div[2];		/* Register encoding, shifted right */
122 	u16 temp;		/* Register values, shifted right */
123 	u8 temp_hot_max;	/* Register value */
124 	u8 temp_hot_hyst;	/* Register value */
125 	u8 temp_os_max;		/* Register value */
126 	u8 temp_os_hyst;	/* Register value */
127 	u16 alarms;		/* Register encoding, combined */
128 };
129 
130 /*
131  * Functions declaration
132  */
133 
134 static int lm80_probe(struct i2c_client *client,
135 		      const struct i2c_device_id *id);
136 static int lm80_detect(struct i2c_client *client, int kind,
137 		       struct i2c_board_info *info);
138 static void lm80_init_client(struct i2c_client *client);
139 static int lm80_remove(struct i2c_client *client);
140 static struct lm80_data *lm80_update_device(struct device *dev);
141 static int lm80_read_value(struct i2c_client *client, u8 reg);
142 static int lm80_write_value(struct i2c_client *client, u8 reg, u8 value);
143 
144 /*
145  * Driver data (common to all clients)
146  */
147 
148 static const struct i2c_device_id lm80_id[] = {
149 	{ "lm80", lm80 },
150 	{ }
151 };
152 MODULE_DEVICE_TABLE(i2c, lm80_id);
153 
154 static struct i2c_driver lm80_driver = {
155 	.class		= I2C_CLASS_HWMON,
156 	.driver = {
157 		.name	= "lm80",
158 	},
159 	.probe		= lm80_probe,
160 	.remove		= lm80_remove,
161 	.id_table	= lm80_id,
162 	.detect		= lm80_detect,
163 	.address_data	= &addr_data,
164 };
165 
166 /*
167  * Sysfs stuff
168  */
169 
170 #define show_in(suffix, value) \
171 static ssize_t show_in_##suffix(struct device *dev, struct device_attribute *attr, char *buf) \
172 { \
173 	int nr = to_sensor_dev_attr(attr)->index; \
174 	struct lm80_data *data = lm80_update_device(dev); \
175 	return sprintf(buf, "%d\n", IN_FROM_REG(data->value[nr])); \
176 }
177 show_in(min, in_min)
178 show_in(max, in_max)
179 show_in(input, in)
180 
181 #define set_in(suffix, value, reg) \
182 static ssize_t set_in_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \
183 	size_t count) \
184 { \
185 	int nr = to_sensor_dev_attr(attr)->index; \
186 	struct i2c_client *client = to_i2c_client(dev); \
187 	struct lm80_data *data = i2c_get_clientdata(client); \
188 	long val = simple_strtol(buf, NULL, 10); \
189  \
190 	mutex_lock(&data->update_lock);\
191 	data->value[nr] = IN_TO_REG(val); \
192 	lm80_write_value(client, reg(nr), data->value[nr]); \
193 	mutex_unlock(&data->update_lock);\
194 	return count; \
195 }
196 set_in(min, in_min, LM80_REG_IN_MIN)
197 set_in(max, in_max, LM80_REG_IN_MAX)
198 
199 #define show_fan(suffix, value) \
200 static ssize_t show_fan_##suffix(struct device *dev, struct device_attribute *attr, char *buf) \
201 { \
202 	int nr = to_sensor_dev_attr(attr)->index; \
203 	struct lm80_data *data = lm80_update_device(dev); \
204 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->value[nr], \
205 		       DIV_FROM_REG(data->fan_div[nr]))); \
206 }
207 show_fan(min, fan_min)
208 show_fan(input, fan)
209 
210 static ssize_t show_fan_div(struct device *dev, struct device_attribute *attr,
211 	char *buf)
212 {
213 	int nr = to_sensor_dev_attr(attr)->index;
214 	struct lm80_data *data = lm80_update_device(dev);
215 	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]));
216 }
217 
218 static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr,
219 	const char *buf, size_t count)
220 {
221 	int nr = to_sensor_dev_attr(attr)->index;
222 	struct i2c_client *client = to_i2c_client(dev);
223 	struct lm80_data *data = i2c_get_clientdata(client);
224 	long val = simple_strtoul(buf, NULL, 10);
225 
226 	mutex_lock(&data->update_lock);
227 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
228 	lm80_write_value(client, LM80_REG_FAN_MIN(nr + 1), data->fan_min[nr]);
229 	mutex_unlock(&data->update_lock);
230 	return count;
231 }
232 
233 /* Note: we save and restore the fan minimum here, because its value is
234    determined in part by the fan divisor.  This follows the principle of
235    least surprise; the user doesn't expect the fan minimum to change just
236    because the divisor changed. */
237 static ssize_t set_fan_div(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 i2c_client *client = to_i2c_client(dev);
242 	struct lm80_data *data = i2c_get_clientdata(client);
243 	unsigned long min, val = simple_strtoul(buf, NULL, 10);
244 	u8 reg;
245 
246 	/* Save fan_min */
247 	mutex_lock(&data->update_lock);
248 	min = FAN_FROM_REG(data->fan_min[nr],
249 			   DIV_FROM_REG(data->fan_div[nr]));
250 
251 	switch (val) {
252 	case 1: data->fan_div[nr] = 0; break;
253 	case 2: data->fan_div[nr] = 1; break;
254 	case 4: data->fan_div[nr] = 2; break;
255 	case 8: data->fan_div[nr] = 3; break;
256 	default:
257 		dev_err(&client->dev, "fan_div value %ld not "
258 			"supported. Choose one of 1, 2, 4 or 8!\n", val);
259 		mutex_unlock(&data->update_lock);
260 		return -EINVAL;
261 	}
262 
263 	reg = (lm80_read_value(client, LM80_REG_FANDIV) & ~(3 << (2 * (nr + 1))))
264 	    | (data->fan_div[nr] << (2 * (nr + 1)));
265 	lm80_write_value(client, LM80_REG_FANDIV, reg);
266 
267 	/* Restore fan_min */
268 	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
269 	lm80_write_value(client, LM80_REG_FAN_MIN(nr + 1), data->fan_min[nr]);
270 	mutex_unlock(&data->update_lock);
271 
272 	return count;
273 }
274 
275 static ssize_t show_temp_input1(struct device *dev, struct device_attribute *attr, char *buf)
276 {
277 	struct lm80_data *data = lm80_update_device(dev);
278 	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp));
279 }
280 
281 #define show_temp(suffix, value) \
282 static ssize_t show_temp_##suffix(struct device *dev, struct device_attribute *attr, char *buf) \
283 { \
284 	struct lm80_data *data = lm80_update_device(dev); \
285 	return sprintf(buf, "%d\n", TEMP_LIMIT_FROM_REG(data->value)); \
286 }
287 show_temp(hot_max, temp_hot_max);
288 show_temp(hot_hyst, temp_hot_hyst);
289 show_temp(os_max, temp_os_max);
290 show_temp(os_hyst, temp_os_hyst);
291 
292 #define set_temp(suffix, value, reg) \
293 static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \
294 	size_t count) \
295 { \
296 	struct i2c_client *client = to_i2c_client(dev); \
297 	struct lm80_data *data = i2c_get_clientdata(client); \
298 	long val = simple_strtoul(buf, NULL, 10); \
299  \
300 	mutex_lock(&data->update_lock); \
301 	data->value = TEMP_LIMIT_TO_REG(val); \
302 	lm80_write_value(client, reg, data->value); \
303 	mutex_unlock(&data->update_lock); \
304 	return count; \
305 }
306 set_temp(hot_max, temp_hot_max, LM80_REG_TEMP_HOT_MAX);
307 set_temp(hot_hyst, temp_hot_hyst, LM80_REG_TEMP_HOT_HYST);
308 set_temp(os_max, temp_os_max, LM80_REG_TEMP_OS_MAX);
309 set_temp(os_hyst, temp_os_hyst, LM80_REG_TEMP_OS_HYST);
310 
311 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
312 			   char *buf)
313 {
314 	struct lm80_data *data = lm80_update_device(dev);
315 	return sprintf(buf, "%u\n", data->alarms);
316 }
317 
318 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
319 			  char *buf)
320 {
321 	int bitnr = to_sensor_dev_attr(attr)->index;
322 	struct lm80_data *data = lm80_update_device(dev);
323 	return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
324 }
325 
326 static SENSOR_DEVICE_ATTR(in0_min, S_IWUSR | S_IRUGO,
327 		show_in_min, set_in_min, 0);
328 static SENSOR_DEVICE_ATTR(in1_min, S_IWUSR | S_IRUGO,
329 		show_in_min, set_in_min, 1);
330 static SENSOR_DEVICE_ATTR(in2_min, S_IWUSR | S_IRUGO,
331 		show_in_min, set_in_min, 2);
332 static SENSOR_DEVICE_ATTR(in3_min, S_IWUSR | S_IRUGO,
333 		show_in_min, set_in_min, 3);
334 static SENSOR_DEVICE_ATTR(in4_min, S_IWUSR | S_IRUGO,
335 		show_in_min, set_in_min, 4);
336 static SENSOR_DEVICE_ATTR(in5_min, S_IWUSR | S_IRUGO,
337 		show_in_min, set_in_min, 5);
338 static SENSOR_DEVICE_ATTR(in6_min, S_IWUSR | S_IRUGO,
339 		show_in_min, set_in_min, 6);
340 static SENSOR_DEVICE_ATTR(in0_max, S_IWUSR | S_IRUGO,
341 		show_in_max, set_in_max, 0);
342 static SENSOR_DEVICE_ATTR(in1_max, S_IWUSR | S_IRUGO,
343 		show_in_max, set_in_max, 1);
344 static SENSOR_DEVICE_ATTR(in2_max, S_IWUSR | S_IRUGO,
345 		show_in_max, set_in_max, 2);
346 static SENSOR_DEVICE_ATTR(in3_max, S_IWUSR | S_IRUGO,
347 		show_in_max, set_in_max, 3);
348 static SENSOR_DEVICE_ATTR(in4_max, S_IWUSR | S_IRUGO,
349 		show_in_max, set_in_max, 4);
350 static SENSOR_DEVICE_ATTR(in5_max, S_IWUSR | S_IRUGO,
351 		show_in_max, set_in_max, 5);
352 static SENSOR_DEVICE_ATTR(in6_max, S_IWUSR | S_IRUGO,
353 		show_in_max, set_in_max, 6);
354 static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, show_in_input, NULL, 0);
355 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_in_input, NULL, 1);
356 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_in_input, NULL, 2);
357 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_in_input, NULL, 3);
358 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_in_input, NULL, 4);
359 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, show_in_input, NULL, 5);
360 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, show_in_input, NULL, 6);
361 static SENSOR_DEVICE_ATTR(fan1_min, S_IWUSR | S_IRUGO,
362 		show_fan_min, set_fan_min, 0);
363 static SENSOR_DEVICE_ATTR(fan2_min, S_IWUSR | S_IRUGO,
364 		show_fan_min, set_fan_min, 1);
365 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan_input, NULL, 0);
366 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan_input, NULL, 1);
367 static SENSOR_DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO,
368 		show_fan_div, set_fan_div, 0);
369 static SENSOR_DEVICE_ATTR(fan2_div, S_IWUSR | S_IRUGO,
370 		show_fan_div, set_fan_div, 1);
371 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
372 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_hot_max,
373     set_temp_hot_max);
374 static DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_hot_hyst,
375     set_temp_hot_hyst);
376 static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp_os_max,
377     set_temp_os_max);
378 static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_os_hyst,
379     set_temp_os_hyst);
380 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
381 static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 0);
382 static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 1);
383 static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, show_alarm, NULL, 2);
384 static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, show_alarm, NULL, 3);
385 static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, show_alarm, NULL, 4);
386 static SENSOR_DEVICE_ATTR(in5_alarm, S_IRUGO, show_alarm, NULL, 5);
387 static SENSOR_DEVICE_ATTR(in6_alarm, S_IRUGO, show_alarm, NULL, 6);
388 static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_alarm, NULL, 10);
389 static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_alarm, NULL, 11);
390 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 8);
391 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 13);
392 
393 /*
394  * Real code
395  */
396 
397 static struct attribute *lm80_attributes[] = {
398 	&sensor_dev_attr_in0_min.dev_attr.attr,
399 	&sensor_dev_attr_in1_min.dev_attr.attr,
400 	&sensor_dev_attr_in2_min.dev_attr.attr,
401 	&sensor_dev_attr_in3_min.dev_attr.attr,
402 	&sensor_dev_attr_in4_min.dev_attr.attr,
403 	&sensor_dev_attr_in5_min.dev_attr.attr,
404 	&sensor_dev_attr_in6_min.dev_attr.attr,
405 	&sensor_dev_attr_in0_max.dev_attr.attr,
406 	&sensor_dev_attr_in1_max.dev_attr.attr,
407 	&sensor_dev_attr_in2_max.dev_attr.attr,
408 	&sensor_dev_attr_in3_max.dev_attr.attr,
409 	&sensor_dev_attr_in4_max.dev_attr.attr,
410 	&sensor_dev_attr_in5_max.dev_attr.attr,
411 	&sensor_dev_attr_in6_max.dev_attr.attr,
412 	&sensor_dev_attr_in0_input.dev_attr.attr,
413 	&sensor_dev_attr_in1_input.dev_attr.attr,
414 	&sensor_dev_attr_in2_input.dev_attr.attr,
415 	&sensor_dev_attr_in3_input.dev_attr.attr,
416 	&sensor_dev_attr_in4_input.dev_attr.attr,
417 	&sensor_dev_attr_in5_input.dev_attr.attr,
418 	&sensor_dev_attr_in6_input.dev_attr.attr,
419 	&sensor_dev_attr_fan1_min.dev_attr.attr,
420 	&sensor_dev_attr_fan2_min.dev_attr.attr,
421 	&sensor_dev_attr_fan1_input.dev_attr.attr,
422 	&sensor_dev_attr_fan2_input.dev_attr.attr,
423 	&sensor_dev_attr_fan1_div.dev_attr.attr,
424 	&sensor_dev_attr_fan2_div.dev_attr.attr,
425 	&dev_attr_temp1_input.attr,
426 	&dev_attr_temp1_max.attr,
427 	&dev_attr_temp1_max_hyst.attr,
428 	&dev_attr_temp1_crit.attr,
429 	&dev_attr_temp1_crit_hyst.attr,
430 	&dev_attr_alarms.attr,
431 	&sensor_dev_attr_in0_alarm.dev_attr.attr,
432 	&sensor_dev_attr_in1_alarm.dev_attr.attr,
433 	&sensor_dev_attr_in2_alarm.dev_attr.attr,
434 	&sensor_dev_attr_in3_alarm.dev_attr.attr,
435 	&sensor_dev_attr_in4_alarm.dev_attr.attr,
436 	&sensor_dev_attr_in5_alarm.dev_attr.attr,
437 	&sensor_dev_attr_in6_alarm.dev_attr.attr,
438 	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
439 	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
440 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
441 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
442 	NULL
443 };
444 
445 static const struct attribute_group lm80_group = {
446 	.attrs = lm80_attributes,
447 };
448 
449 /* Return 0 if detection is successful, -ENODEV otherwise */
450 static int lm80_detect(struct i2c_client *client, int kind,
451 		       struct i2c_board_info *info)
452 {
453 	struct i2c_adapter *adapter = client->adapter;
454 	int i, cur;
455 
456 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
457 		return -ENODEV;
458 
459 	/* Now, we do the remaining detection. It is lousy. */
460 	if (lm80_read_value(client, LM80_REG_ALARM2) & 0xc0)
461 		return -ENODEV;
462 	for (i = 0x2a; i <= 0x3d; i++) {
463 		cur = i2c_smbus_read_byte_data(client, i);
464 		if ((i2c_smbus_read_byte_data(client, i + 0x40) != cur)
465 		 || (i2c_smbus_read_byte_data(client, i + 0x80) != cur)
466 		 || (i2c_smbus_read_byte_data(client, i + 0xc0) != cur))
467 		    return -ENODEV;
468 	}
469 
470 	strlcpy(info->type, "lm80", I2C_NAME_SIZE);
471 
472 	return 0;
473 }
474 
475 static int lm80_probe(struct i2c_client *client,
476 		      const struct i2c_device_id *id)
477 {
478 	struct lm80_data *data;
479 	int err;
480 
481 	data = kzalloc(sizeof(struct lm80_data), GFP_KERNEL);
482 	if (!data) {
483 		err = -ENOMEM;
484 		goto exit;
485 	}
486 
487 	i2c_set_clientdata(client, data);
488 	mutex_init(&data->update_lock);
489 
490 	/* Initialize the LM80 chip */
491 	lm80_init_client(client);
492 
493 	/* A few vars need to be filled upon startup */
494 	data->fan_min[0] = lm80_read_value(client, LM80_REG_FAN_MIN(1));
495 	data->fan_min[1] = lm80_read_value(client, LM80_REG_FAN_MIN(2));
496 
497 	/* Register sysfs hooks */
498 	if ((err = sysfs_create_group(&client->dev.kobj, &lm80_group)))
499 		goto error_free;
500 
501 	data->hwmon_dev = hwmon_device_register(&client->dev);
502 	if (IS_ERR(data->hwmon_dev)) {
503 		err = PTR_ERR(data->hwmon_dev);
504 		goto error_remove;
505 	}
506 
507 	return 0;
508 
509 error_remove:
510 	sysfs_remove_group(&client->dev.kobj, &lm80_group);
511 error_free:
512 	kfree(data);
513 exit:
514 	return err;
515 }
516 
517 static int lm80_remove(struct i2c_client *client)
518 {
519 	struct lm80_data *data = i2c_get_clientdata(client);
520 
521 	hwmon_device_unregister(data->hwmon_dev);
522 	sysfs_remove_group(&client->dev.kobj, &lm80_group);
523 
524 	kfree(data);
525 	return 0;
526 }
527 
528 static int lm80_read_value(struct i2c_client *client, u8 reg)
529 {
530 	return i2c_smbus_read_byte_data(client, reg);
531 }
532 
533 static int lm80_write_value(struct i2c_client *client, u8 reg, u8 value)
534 {
535 	return i2c_smbus_write_byte_data(client, reg, value);
536 }
537 
538 /* Called when we have found a new LM80. */
539 static void lm80_init_client(struct i2c_client *client)
540 {
541 	/* Reset all except Watchdog values and last conversion values
542 	   This sets fan-divs to 2, among others. This makes most other
543 	   initializations unnecessary */
544 	lm80_write_value(client, LM80_REG_CONFIG, 0x80);
545 	/* Set 11-bit temperature resolution */
546 	lm80_write_value(client, LM80_REG_RES, 0x08);
547 
548 	/* Start monitoring */
549 	lm80_write_value(client, LM80_REG_CONFIG, 0x01);
550 }
551 
552 static struct lm80_data *lm80_update_device(struct device *dev)
553 {
554 	struct i2c_client *client = to_i2c_client(dev);
555 	struct lm80_data *data = i2c_get_clientdata(client);
556 	int i;
557 
558 	mutex_lock(&data->update_lock);
559 
560 	if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
561 		dev_dbg(&client->dev, "Starting lm80 update\n");
562 		for (i = 0; i <= 6; i++) {
563 			data->in[i] =
564 			    lm80_read_value(client, LM80_REG_IN(i));
565 			data->in_min[i] =
566 			    lm80_read_value(client, LM80_REG_IN_MIN(i));
567 			data->in_max[i] =
568 			    lm80_read_value(client, LM80_REG_IN_MAX(i));
569 		}
570 		data->fan[0] = lm80_read_value(client, LM80_REG_FAN1);
571 		data->fan_min[0] =
572 		    lm80_read_value(client, LM80_REG_FAN_MIN(1));
573 		data->fan[1] = lm80_read_value(client, LM80_REG_FAN2);
574 		data->fan_min[1] =
575 		    lm80_read_value(client, LM80_REG_FAN_MIN(2));
576 
577 		data->temp =
578 		    (lm80_read_value(client, LM80_REG_TEMP) << 8) |
579 		    (lm80_read_value(client, LM80_REG_RES) & 0xf0);
580 		data->temp_os_max =
581 		    lm80_read_value(client, LM80_REG_TEMP_OS_MAX);
582 		data->temp_os_hyst =
583 		    lm80_read_value(client, LM80_REG_TEMP_OS_HYST);
584 		data->temp_hot_max =
585 		    lm80_read_value(client, LM80_REG_TEMP_HOT_MAX);
586 		data->temp_hot_hyst =
587 		    lm80_read_value(client, LM80_REG_TEMP_HOT_HYST);
588 
589 		i = lm80_read_value(client, LM80_REG_FANDIV);
590 		data->fan_div[0] = (i >> 2) & 0x03;
591 		data->fan_div[1] = (i >> 4) & 0x03;
592 		data->alarms = lm80_read_value(client, LM80_REG_ALARM1) +
593 		    (lm80_read_value(client, LM80_REG_ALARM2) << 8);
594 		data->last_updated = jiffies;
595 		data->valid = 1;
596 	}
597 
598 	mutex_unlock(&data->update_lock);
599 
600 	return data;
601 }
602 
603 static int __init sensors_lm80_init(void)
604 {
605 	return i2c_add_driver(&lm80_driver);
606 }
607 
608 static void __exit sensors_lm80_exit(void)
609 {
610 	i2c_del_driver(&lm80_driver);
611 }
612 
613 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
614 	"Philip Edelbrock <phil@netroedge.com>");
615 MODULE_DESCRIPTION("LM80 driver");
616 MODULE_LICENSE("GPL");
617 
618 module_init(sensors_lm80_init);
619 module_exit(sensors_lm80_exit);
620