xref: /openbmc/linux/drivers/hwmon/lm80.c (revision 87c2ce3b)
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/err.h>
31 
32 /* Addresses to scan */
33 static unsigned short normal_i2c[] = { 0x28, 0x29, 0x2a, 0x2b, 0x2c,
34 					0x2d, 0x2e, 0x2f, I2C_CLIENT_END };
35 
36 /* Insmod parameters */
37 I2C_CLIENT_INSMOD_1(lm80);
38 
39 /* Many LM80 constants specified below */
40 
41 /* The LM80 registers */
42 #define LM80_REG_IN_MAX(nr)		(0x2a + (nr) * 2)
43 #define LM80_REG_IN_MIN(nr)		(0x2b + (nr) * 2)
44 #define LM80_REG_IN(nr)			(0x20 + (nr))
45 
46 #define LM80_REG_FAN1			0x28
47 #define LM80_REG_FAN2			0x29
48 #define LM80_REG_FAN_MIN(nr)		(0x3b + (nr))
49 
50 #define LM80_REG_TEMP			0x27
51 #define LM80_REG_TEMP_HOT_MAX		0x38
52 #define LM80_REG_TEMP_HOT_HYST		0x39
53 #define LM80_REG_TEMP_OS_MAX		0x3a
54 #define LM80_REG_TEMP_OS_HYST		0x3b
55 
56 #define LM80_REG_CONFIG			0x00
57 #define LM80_REG_ALARM1			0x01
58 #define LM80_REG_ALARM2			0x02
59 #define LM80_REG_MASK1			0x03
60 #define LM80_REG_MASK2			0x04
61 #define LM80_REG_FANDIV			0x05
62 #define LM80_REG_RES			0x06
63 
64 
65 /* Conversions. Rounding and limit checking is only done on the TO_REG
66    variants. Note that you should be a bit careful with which arguments
67    these macros are called: arguments may be evaluated more than once.
68    Fixing this is just not worth it. */
69 
70 #define IN_TO_REG(val)		(SENSORS_LIMIT(((val)+5)/10,0,255))
71 #define IN_FROM_REG(val)	((val)*10)
72 
73 static inline unsigned char FAN_TO_REG(unsigned rpm, unsigned div)
74 {
75 	if (rpm == 0)
76 		return 255;
77 	rpm = SENSORS_LIMIT(rpm, 1, 1000000);
78 	return SENSORS_LIMIT((1350000 + rpm*div / 2) / (rpm*div), 1, 254);
79 }
80 
81 #define FAN_FROM_REG(val,div)	((val)==0?-1:\
82 				(val)==255?0:1350000/((div)*(val)))
83 
84 static inline long TEMP_FROM_REG(u16 temp)
85 {
86 	long res;
87 
88 	temp >>= 4;
89 	if (temp < 0x0800)
90 		res = 625 * (long) temp;
91 	else
92 		res = ((long) temp - 0x01000) * 625;
93 
94 	return res / 10;
95 }
96 
97 #define TEMP_LIMIT_FROM_REG(val)	(((val)>0x80?(val)-0x100:(val))*1000)
98 
99 #define TEMP_LIMIT_TO_REG(val)		SENSORS_LIMIT((val)<0?\
100 					((val)-500)/1000:((val)+500)/1000,0,255)
101 
102 #define DIV_FROM_REG(val)		(1 << (val))
103 
104 /*
105  * Client data (each client gets its own)
106  */
107 
108 struct lm80_data {
109 	struct i2c_client client;
110 	struct class_device *class_dev;
111 	struct semaphore update_lock;
112 	char valid;		/* !=0 if following fields are valid */
113 	unsigned long last_updated;	/* In jiffies */
114 
115 	u8 in[7];		/* Register value */
116 	u8 in_max[7];		/* Register value */
117 	u8 in_min[7];		/* Register value */
118 	u8 fan[2];		/* Register value */
119 	u8 fan_min[2];		/* Register value */
120 	u8 fan_div[2];		/* Register encoding, shifted right */
121 	u16 temp;		/* Register values, shifted right */
122 	u8 temp_hot_max;	/* Register value */
123 	u8 temp_hot_hyst;	/* Register value */
124 	u8 temp_os_max;		/* Register value */
125 	u8 temp_os_hyst;	/* Register value */
126 	u16 alarms;		/* Register encoding, combined */
127 };
128 
129 /*
130  * Functions declaration
131  */
132 
133 static int lm80_attach_adapter(struct i2c_adapter *adapter);
134 static int lm80_detect(struct i2c_adapter *adapter, int address, int kind);
135 static void lm80_init_client(struct i2c_client *client);
136 static int lm80_detach_client(struct i2c_client *client);
137 static struct lm80_data *lm80_update_device(struct device *dev);
138 static int lm80_read_value(struct i2c_client *client, u8 reg);
139 static int lm80_write_value(struct i2c_client *client, u8 reg, u8 value);
140 
141 /*
142  * Driver data (common to all clients)
143  */
144 
145 static struct i2c_driver lm80_driver = {
146 	.driver = {
147 		.name	= "lm80",
148 	},
149 	.id		= I2C_DRIVERID_LM80,
150 	.attach_adapter	= lm80_attach_adapter,
151 	.detach_client	= lm80_detach_client,
152 };
153 
154 /*
155  * Sysfs stuff
156  */
157 
158 #define show_in(suffix, value) \
159 static ssize_t show_in_##suffix(struct device *dev, struct device_attribute *attr, char *buf) \
160 { \
161 	struct lm80_data *data = lm80_update_device(dev); \
162 	return sprintf(buf, "%d\n", IN_FROM_REG(data->value)); \
163 }
164 show_in(min0, in_min[0]);
165 show_in(min1, in_min[1]);
166 show_in(min2, in_min[2]);
167 show_in(min3, in_min[3]);
168 show_in(min4, in_min[4]);
169 show_in(min5, in_min[5]);
170 show_in(min6, in_min[6]);
171 show_in(max0, in_max[0]);
172 show_in(max1, in_max[1]);
173 show_in(max2, in_max[2]);
174 show_in(max3, in_max[3]);
175 show_in(max4, in_max[4]);
176 show_in(max5, in_max[5]);
177 show_in(max6, in_max[6]);
178 show_in(input0, in[0]);
179 show_in(input1, in[1]);
180 show_in(input2, in[2]);
181 show_in(input3, in[3]);
182 show_in(input4, in[4]);
183 show_in(input5, in[5]);
184 show_in(input6, in[6]);
185 
186 #define set_in(suffix, value, reg) \
187 static ssize_t set_in_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \
188 	size_t count) \
189 { \
190 	struct i2c_client *client = to_i2c_client(dev); \
191 	struct lm80_data *data = i2c_get_clientdata(client); \
192 	long val = simple_strtol(buf, NULL, 10); \
193  \
194 	down(&data->update_lock);\
195 	data->value = IN_TO_REG(val); \
196 	lm80_write_value(client, reg, data->value); \
197 	up(&data->update_lock);\
198 	return count; \
199 }
200 set_in(min0, in_min[0], LM80_REG_IN_MIN(0));
201 set_in(min1, in_min[1], LM80_REG_IN_MIN(1));
202 set_in(min2, in_min[2], LM80_REG_IN_MIN(2));
203 set_in(min3, in_min[3], LM80_REG_IN_MIN(3));
204 set_in(min4, in_min[4], LM80_REG_IN_MIN(4));
205 set_in(min5, in_min[5], LM80_REG_IN_MIN(5));
206 set_in(min6, in_min[6], LM80_REG_IN_MIN(6));
207 set_in(max0, in_max[0], LM80_REG_IN_MAX(0));
208 set_in(max1, in_max[1], LM80_REG_IN_MAX(1));
209 set_in(max2, in_max[2], LM80_REG_IN_MAX(2));
210 set_in(max3, in_max[3], LM80_REG_IN_MAX(3));
211 set_in(max4, in_max[4], LM80_REG_IN_MAX(4));
212 set_in(max5, in_max[5], LM80_REG_IN_MAX(5));
213 set_in(max6, in_max[6], LM80_REG_IN_MAX(6));
214 
215 #define show_fan(suffix, value, div) \
216 static ssize_t show_fan_##suffix(struct device *dev, struct device_attribute *attr, char *buf) \
217 { \
218 	struct lm80_data *data = lm80_update_device(dev); \
219 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->value, \
220 		       DIV_FROM_REG(data->div))); \
221 }
222 show_fan(min1, fan_min[0], fan_div[0]);
223 show_fan(min2, fan_min[1], fan_div[1]);
224 show_fan(input1, fan[0], fan_div[0]);
225 show_fan(input2, fan[1], fan_div[1]);
226 
227 #define show_fan_div(suffix, value) \
228 static ssize_t show_fan_div##suffix(struct device *dev, struct device_attribute *attr, char *buf) \
229 { \
230 	struct lm80_data *data = lm80_update_device(dev); \
231 	return sprintf(buf, "%d\n", DIV_FROM_REG(data->value)); \
232 }
233 show_fan_div(1, fan_div[0]);
234 show_fan_div(2, fan_div[1]);
235 
236 #define set_fan(suffix, value, reg, div) \
237 static ssize_t set_fan_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \
238 	size_t count) \
239 { \
240 	struct i2c_client *client = to_i2c_client(dev); \
241 	struct lm80_data *data = i2c_get_clientdata(client); \
242 	long val = simple_strtoul(buf, NULL, 10); \
243  \
244 	down(&data->update_lock);\
245 	data->value = FAN_TO_REG(val, DIV_FROM_REG(data->div)); \
246 	lm80_write_value(client, reg, data->value); \
247 	up(&data->update_lock);\
248 	return count; \
249 }
250 set_fan(min1, fan_min[0], LM80_REG_FAN_MIN(1), fan_div[0]);
251 set_fan(min2, fan_min[1], LM80_REG_FAN_MIN(2), fan_div[1]);
252 
253 /* Note: we save and restore the fan minimum here, because its value is
254    determined in part by the fan divisor.  This follows the principle of
255    least suprise; the user doesn't expect the fan minimum to change just
256    because the divisor changed. */
257 static ssize_t set_fan_div(struct device *dev, const char *buf,
258 	size_t count, int nr)
259 {
260 	struct i2c_client *client = to_i2c_client(dev);
261 	struct lm80_data *data = i2c_get_clientdata(client);
262 	unsigned long min, val = simple_strtoul(buf, NULL, 10);
263 	u8 reg;
264 
265 	/* Save fan_min */
266 	down(&data->update_lock);
267 	min = FAN_FROM_REG(data->fan_min[nr],
268 			   DIV_FROM_REG(data->fan_div[nr]));
269 
270 	switch (val) {
271 	case 1: data->fan_div[nr] = 0; break;
272 	case 2: data->fan_div[nr] = 1; break;
273 	case 4: data->fan_div[nr] = 2; break;
274 	case 8: data->fan_div[nr] = 3; break;
275 	default:
276 		dev_err(&client->dev, "fan_div value %ld not "
277 			"supported. Choose one of 1, 2, 4 or 8!\n", val);
278 		up(&data->update_lock);
279 		return -EINVAL;
280 	}
281 
282 	reg = (lm80_read_value(client, LM80_REG_FANDIV) & ~(3 << (2 * (nr + 1))))
283 	    | (data->fan_div[nr] << (2 * (nr + 1)));
284 	lm80_write_value(client, LM80_REG_FANDIV, reg);
285 
286 	/* Restore fan_min */
287 	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
288 	lm80_write_value(client, LM80_REG_FAN_MIN(nr + 1), data->fan_min[nr]);
289 	up(&data->update_lock);
290 
291 	return count;
292 }
293 
294 #define set_fan_div(number) \
295 static ssize_t set_fan_div##number(struct device *dev, struct device_attribute *attr, const char *buf, \
296 	size_t count) \
297 { \
298 	return set_fan_div(dev, buf, count, number - 1); \
299 }
300 set_fan_div(1);
301 set_fan_div(2);
302 
303 static ssize_t show_temp_input1(struct device *dev, struct device_attribute *attr, char *buf)
304 {
305 	struct lm80_data *data = lm80_update_device(dev);
306 	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp));
307 }
308 
309 #define show_temp(suffix, value) \
310 static ssize_t show_temp_##suffix(struct device *dev, struct device_attribute *attr, char *buf) \
311 { \
312 	struct lm80_data *data = lm80_update_device(dev); \
313 	return sprintf(buf, "%d\n", TEMP_LIMIT_FROM_REG(data->value)); \
314 }
315 show_temp(hot_max, temp_hot_max);
316 show_temp(hot_hyst, temp_hot_hyst);
317 show_temp(os_max, temp_os_max);
318 show_temp(os_hyst, temp_os_hyst);
319 
320 #define set_temp(suffix, value, reg) \
321 static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \
322 	size_t count) \
323 { \
324 	struct i2c_client *client = to_i2c_client(dev); \
325 	struct lm80_data *data = i2c_get_clientdata(client); \
326 	long val = simple_strtoul(buf, NULL, 10); \
327  \
328 	down(&data->update_lock); \
329 	data->value = TEMP_LIMIT_TO_REG(val); \
330 	lm80_write_value(client, reg, data->value); \
331 	up(&data->update_lock); \
332 	return count; \
333 }
334 set_temp(hot_max, temp_hot_max, LM80_REG_TEMP_HOT_MAX);
335 set_temp(hot_hyst, temp_hot_hyst, LM80_REG_TEMP_HOT_HYST);
336 set_temp(os_max, temp_os_max, LM80_REG_TEMP_OS_MAX);
337 set_temp(os_hyst, temp_os_hyst, LM80_REG_TEMP_OS_HYST);
338 
339 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
340 {
341 	struct lm80_data *data = lm80_update_device(dev);
342 	return sprintf(buf, "%u\n", data->alarms);
343 }
344 
345 static DEVICE_ATTR(in0_min, S_IWUSR | S_IRUGO, show_in_min0, set_in_min0);
346 static DEVICE_ATTR(in1_min, S_IWUSR | S_IRUGO, show_in_min1, set_in_min1);
347 static DEVICE_ATTR(in2_min, S_IWUSR | S_IRUGO, show_in_min2, set_in_min2);
348 static DEVICE_ATTR(in3_min, S_IWUSR | S_IRUGO, show_in_min3, set_in_min3);
349 static DEVICE_ATTR(in4_min, S_IWUSR | S_IRUGO, show_in_min4, set_in_min4);
350 static DEVICE_ATTR(in5_min, S_IWUSR | S_IRUGO, show_in_min5, set_in_min5);
351 static DEVICE_ATTR(in6_min, S_IWUSR | S_IRUGO, show_in_min6, set_in_min6);
352 static DEVICE_ATTR(in0_max, S_IWUSR | S_IRUGO, show_in_max0, set_in_max0);
353 static DEVICE_ATTR(in1_max, S_IWUSR | S_IRUGO, show_in_max1, set_in_max1);
354 static DEVICE_ATTR(in2_max, S_IWUSR | S_IRUGO, show_in_max2, set_in_max2);
355 static DEVICE_ATTR(in3_max, S_IWUSR | S_IRUGO, show_in_max3, set_in_max3);
356 static DEVICE_ATTR(in4_max, S_IWUSR | S_IRUGO, show_in_max4, set_in_max4);
357 static DEVICE_ATTR(in5_max, S_IWUSR | S_IRUGO, show_in_max5, set_in_max5);
358 static DEVICE_ATTR(in6_max, S_IWUSR | S_IRUGO, show_in_max6, set_in_max6);
359 static DEVICE_ATTR(in0_input, S_IRUGO, show_in_input0, NULL);
360 static DEVICE_ATTR(in1_input, S_IRUGO, show_in_input1, NULL);
361 static DEVICE_ATTR(in2_input, S_IRUGO, show_in_input2, NULL);
362 static DEVICE_ATTR(in3_input, S_IRUGO, show_in_input3, NULL);
363 static DEVICE_ATTR(in4_input, S_IRUGO, show_in_input4, NULL);
364 static DEVICE_ATTR(in5_input, S_IRUGO, show_in_input5, NULL);
365 static DEVICE_ATTR(in6_input, S_IRUGO, show_in_input6, NULL);
366 static DEVICE_ATTR(fan1_min, S_IWUSR | S_IRUGO, show_fan_min1,
367     set_fan_min1);
368 static DEVICE_ATTR(fan2_min, S_IWUSR | S_IRUGO, show_fan_min2,
369     set_fan_min2);
370 static DEVICE_ATTR(fan1_input, S_IRUGO, show_fan_input1, NULL);
371 static DEVICE_ATTR(fan2_input, S_IRUGO, show_fan_input2, NULL);
372 static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, show_fan_div1, set_fan_div1);
373 static DEVICE_ATTR(fan2_div, S_IWUSR | S_IRUGO, show_fan_div2, set_fan_div2);
374 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
375 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_hot_max,
376     set_temp_hot_max);
377 static DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_hot_hyst,
378     set_temp_hot_hyst);
379 static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp_os_max,
380     set_temp_os_max);
381 static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_os_hyst,
382     set_temp_os_hyst);
383 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
384 
385 /*
386  * Real code
387  */
388 
389 static int lm80_attach_adapter(struct i2c_adapter *adapter)
390 {
391 	if (!(adapter->class & I2C_CLASS_HWMON))
392 		return 0;
393 	return i2c_probe(adapter, &addr_data, lm80_detect);
394 }
395 
396 static int lm80_detect(struct i2c_adapter *adapter, int address, int kind)
397 {
398 	int i, cur;
399 	struct i2c_client *new_client;
400 	struct lm80_data *data;
401 	int err = 0;
402 	const char *name;
403 
404 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
405 		goto exit;
406 
407 	/* OK. For now, we presume we have a valid client. We now create the
408 	   client structure, even though we cannot fill it completely yet.
409 	   But it allows us to access lm80_{read,write}_value. */
410 	if (!(data = kzalloc(sizeof(struct lm80_data), GFP_KERNEL))) {
411 		err = -ENOMEM;
412 		goto exit;
413 	}
414 
415 	new_client = &data->client;
416 	i2c_set_clientdata(new_client, data);
417 	new_client->addr = address;
418 	new_client->adapter = adapter;
419 	new_client->driver = &lm80_driver;
420 	new_client->flags = 0;
421 
422 	/* Now, we do the remaining detection. It is lousy. */
423 	if (lm80_read_value(new_client, LM80_REG_ALARM2) & 0xc0)
424 		goto error_free;
425 	for (i = 0x2a; i <= 0x3d; i++) {
426 		cur = i2c_smbus_read_byte_data(new_client, i);
427 		if ((i2c_smbus_read_byte_data(new_client, i + 0x40) != cur)
428 		 || (i2c_smbus_read_byte_data(new_client, i + 0x80) != cur)
429 		 || (i2c_smbus_read_byte_data(new_client, i + 0xc0) != cur))
430 		    goto error_free;
431 	}
432 
433 	/* Determine the chip type - only one kind supported! */
434 	kind = lm80;
435 	name = "lm80";
436 
437 	/* Fill in the remaining client fields and put it into the global list */
438 	strlcpy(new_client->name, name, I2C_NAME_SIZE);
439 	data->valid = 0;
440 	init_MUTEX(&data->update_lock);
441 
442 	/* Tell the I2C layer a new client has arrived */
443 	if ((err = i2c_attach_client(new_client)))
444 		goto error_free;
445 
446 	/* Initialize the LM80 chip */
447 	lm80_init_client(new_client);
448 
449 	/* A few vars need to be filled upon startup */
450 	data->fan_min[0] = lm80_read_value(new_client, LM80_REG_FAN_MIN(1));
451 	data->fan_min[1] = lm80_read_value(new_client, LM80_REG_FAN_MIN(2));
452 
453 	/* Register sysfs hooks */
454 	data->class_dev = hwmon_device_register(&new_client->dev);
455 	if (IS_ERR(data->class_dev)) {
456 		err = PTR_ERR(data->class_dev);
457 		goto error_detach;
458 	}
459 
460 	device_create_file(&new_client->dev, &dev_attr_in0_min);
461 	device_create_file(&new_client->dev, &dev_attr_in1_min);
462 	device_create_file(&new_client->dev, &dev_attr_in2_min);
463 	device_create_file(&new_client->dev, &dev_attr_in3_min);
464 	device_create_file(&new_client->dev, &dev_attr_in4_min);
465 	device_create_file(&new_client->dev, &dev_attr_in5_min);
466 	device_create_file(&new_client->dev, &dev_attr_in6_min);
467 	device_create_file(&new_client->dev, &dev_attr_in0_max);
468 	device_create_file(&new_client->dev, &dev_attr_in1_max);
469 	device_create_file(&new_client->dev, &dev_attr_in2_max);
470 	device_create_file(&new_client->dev, &dev_attr_in3_max);
471 	device_create_file(&new_client->dev, &dev_attr_in4_max);
472 	device_create_file(&new_client->dev, &dev_attr_in5_max);
473 	device_create_file(&new_client->dev, &dev_attr_in6_max);
474 	device_create_file(&new_client->dev, &dev_attr_in0_input);
475 	device_create_file(&new_client->dev, &dev_attr_in1_input);
476 	device_create_file(&new_client->dev, &dev_attr_in2_input);
477 	device_create_file(&new_client->dev, &dev_attr_in3_input);
478 	device_create_file(&new_client->dev, &dev_attr_in4_input);
479 	device_create_file(&new_client->dev, &dev_attr_in5_input);
480 	device_create_file(&new_client->dev, &dev_attr_in6_input);
481 	device_create_file(&new_client->dev, &dev_attr_fan1_min);
482 	device_create_file(&new_client->dev, &dev_attr_fan2_min);
483 	device_create_file(&new_client->dev, &dev_attr_fan1_input);
484 	device_create_file(&new_client->dev, &dev_attr_fan2_input);
485 	device_create_file(&new_client->dev, &dev_attr_fan1_div);
486 	device_create_file(&new_client->dev, &dev_attr_fan2_div);
487 	device_create_file(&new_client->dev, &dev_attr_temp1_input);
488 	device_create_file(&new_client->dev, &dev_attr_temp1_max);
489 	device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst);
490 	device_create_file(&new_client->dev, &dev_attr_temp1_crit);
491 	device_create_file(&new_client->dev, &dev_attr_temp1_crit_hyst);
492 	device_create_file(&new_client->dev, &dev_attr_alarms);
493 
494 	return 0;
495 
496 error_detach:
497 	i2c_detach_client(new_client);
498 error_free:
499 	kfree(data);
500 exit:
501 	return err;
502 }
503 
504 static int lm80_detach_client(struct i2c_client *client)
505 {
506 	struct lm80_data *data = i2c_get_clientdata(client);
507 	int err;
508 
509 	hwmon_device_unregister(data->class_dev);
510 
511 	if ((err = i2c_detach_client(client)))
512 		return err;
513 
514 	kfree(data);
515 	return 0;
516 }
517 
518 static int lm80_read_value(struct i2c_client *client, u8 reg)
519 {
520 	return i2c_smbus_read_byte_data(client, reg);
521 }
522 
523 static int lm80_write_value(struct i2c_client *client, u8 reg, u8 value)
524 {
525 	return i2c_smbus_write_byte_data(client, reg, value);
526 }
527 
528 /* Called when we have found a new LM80. */
529 static void lm80_init_client(struct i2c_client *client)
530 {
531 	/* Reset all except Watchdog values and last conversion values
532 	   This sets fan-divs to 2, among others. This makes most other
533 	   initializations unnecessary */
534 	lm80_write_value(client, LM80_REG_CONFIG, 0x80);
535 	/* Set 11-bit temperature resolution */
536 	lm80_write_value(client, LM80_REG_RES, 0x08);
537 
538 	/* Start monitoring */
539 	lm80_write_value(client, LM80_REG_CONFIG, 0x01);
540 }
541 
542 static struct lm80_data *lm80_update_device(struct device *dev)
543 {
544 	struct i2c_client *client = to_i2c_client(dev);
545 	struct lm80_data *data = i2c_get_clientdata(client);
546 	int i;
547 
548 	down(&data->update_lock);
549 
550 	if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
551 		dev_dbg(&client->dev, "Starting lm80 update\n");
552 		for (i = 0; i <= 6; i++) {
553 			data->in[i] =
554 			    lm80_read_value(client, LM80_REG_IN(i));
555 			data->in_min[i] =
556 			    lm80_read_value(client, LM80_REG_IN_MIN(i));
557 			data->in_max[i] =
558 			    lm80_read_value(client, LM80_REG_IN_MAX(i));
559 		}
560 		data->fan[0] = lm80_read_value(client, LM80_REG_FAN1);
561 		data->fan_min[0] =
562 		    lm80_read_value(client, LM80_REG_FAN_MIN(1));
563 		data->fan[1] = lm80_read_value(client, LM80_REG_FAN2);
564 		data->fan_min[1] =
565 		    lm80_read_value(client, LM80_REG_FAN_MIN(2));
566 
567 		data->temp =
568 		    (lm80_read_value(client, LM80_REG_TEMP) << 8) |
569 		    (lm80_read_value(client, LM80_REG_RES) & 0xf0);
570 		data->temp_os_max =
571 		    lm80_read_value(client, LM80_REG_TEMP_OS_MAX);
572 		data->temp_os_hyst =
573 		    lm80_read_value(client, LM80_REG_TEMP_OS_HYST);
574 		data->temp_hot_max =
575 		    lm80_read_value(client, LM80_REG_TEMP_HOT_MAX);
576 		data->temp_hot_hyst =
577 		    lm80_read_value(client, LM80_REG_TEMP_HOT_HYST);
578 
579 		i = lm80_read_value(client, LM80_REG_FANDIV);
580 		data->fan_div[0] = (i >> 2) & 0x03;
581 		data->fan_div[1] = (i >> 4) & 0x03;
582 		data->alarms = lm80_read_value(client, LM80_REG_ALARM1) +
583 		    (lm80_read_value(client, LM80_REG_ALARM2) << 8);
584 		data->last_updated = jiffies;
585 		data->valid = 1;
586 	}
587 
588 	up(&data->update_lock);
589 
590 	return data;
591 }
592 
593 static int __init sensors_lm80_init(void)
594 {
595 	return i2c_add_driver(&lm80_driver);
596 }
597 
598 static void __exit sensors_lm80_exit(void)
599 {
600 	i2c_del_driver(&lm80_driver);
601 }
602 
603 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
604 	"Philip Edelbrock <phil@netroedge.com>");
605 MODULE_DESCRIPTION("LM80 driver");
606 MODULE_LICENSE("GPL");
607 
608 module_init(sensors_lm80_init);
609 module_exit(sensors_lm80_exit);
610