xref: /openbmc/linux/drivers/hwmon/lm80.c (revision afb46f79)
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 #define LM96080_REG_CONV_RATE		0x07
64 #define LM96080_REG_MAN_ID		0x3e
65 #define LM96080_REG_DEV_ID		0x3f
66 
67 
68 /*
69  * Conversions. Rounding and limit checking is only done on the TO_REG
70  * variants. Note that you should be a bit careful with which arguments
71  * these macros are called: arguments may be evaluated more than once.
72  * Fixing this is just not worth it.
73  */
74 
75 #define IN_TO_REG(val)		(clamp_val(((val) + 5) / 10, 0, 255))
76 #define IN_FROM_REG(val)	((val) * 10)
77 
78 static inline unsigned char FAN_TO_REG(unsigned rpm, unsigned div)
79 {
80 	if (rpm == 0)
81 		return 255;
82 	rpm = clamp_val(rpm, 1, 1000000);
83 	return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
84 }
85 
86 #define FAN_FROM_REG(val, div)	((val) == 0 ? -1 : \
87 				(val) == 255 ? 0 : 1350000/((div) * (val)))
88 
89 static inline long TEMP_FROM_REG(u16 temp)
90 {
91 	long res;
92 
93 	temp >>= 4;
94 	if (temp < 0x0800)
95 		res = 625 * (long) temp;
96 	else
97 		res = ((long) temp - 0x01000) * 625;
98 
99 	return res / 10;
100 }
101 
102 #define TEMP_LIMIT_FROM_REG(val)	(((val) > 0x80 ? \
103 	(val) - 0x100 : (val)) * 1000)
104 
105 #define TEMP_LIMIT_TO_REG(val)		clamp_val((val) < 0 ? \
106 	((val) - 500) / 1000 : ((val) + 500) / 1000, 0, 255)
107 
108 #define DIV_FROM_REG(val)		(1 << (val))
109 
110 /*
111  * Client data (each client gets its own)
112  */
113 
114 struct lm80_data {
115 	struct i2c_client *client;
116 	struct mutex update_lock;
117 	char error;		/* !=0 if error occurred during last update */
118 	char valid;		/* !=0 if following fields are valid */
119 	unsigned long last_updated;	/* In jiffies */
120 
121 	u8 in[7];		/* Register value */
122 	u8 in_max[7];		/* Register value */
123 	u8 in_min[7];		/* Register value */
124 	u8 fan[2];		/* Register value */
125 	u8 fan_min[2];		/* Register value */
126 	u8 fan_div[2];		/* Register encoding, shifted right */
127 	u16 temp;		/* Register values, shifted right */
128 	u8 temp_hot_max;	/* Register value */
129 	u8 temp_hot_hyst;	/* Register value */
130 	u8 temp_os_max;		/* Register value */
131 	u8 temp_os_hyst;	/* Register value */
132 	u16 alarms;		/* Register encoding, combined */
133 };
134 
135 /*
136  * Functions declaration
137  */
138 
139 static int lm80_probe(struct i2c_client *client,
140 		      const struct i2c_device_id *id);
141 static int lm80_detect(struct i2c_client *client, struct i2c_board_info *info);
142 static void lm80_init_client(struct i2c_client *client);
143 static struct lm80_data *lm80_update_device(struct device *dev);
144 static int lm80_read_value(struct i2c_client *client, u8 reg);
145 static int lm80_write_value(struct i2c_client *client, u8 reg, u8 value);
146 
147 /*
148  * Driver data (common to all clients)
149  */
150 
151 static const struct i2c_device_id lm80_id[] = {
152 	{ "lm80", 0 },
153 	{ "lm96080", 1 },
154 	{ }
155 };
156 MODULE_DEVICE_TABLE(i2c, lm80_id);
157 
158 static struct i2c_driver lm80_driver = {
159 	.class		= I2C_CLASS_HWMON,
160 	.driver = {
161 		.name	= "lm80",
162 	},
163 	.probe		= lm80_probe,
164 	.id_table	= lm80_id,
165 	.detect		= lm80_detect,
166 	.address_list	= normal_i2c,
167 };
168 
169 /*
170  * Sysfs stuff
171  */
172 
173 #define show_in(suffix, value) \
174 static ssize_t show_in_##suffix(struct device *dev, \
175 	struct device_attribute *attr, char *buf) \
176 { \
177 	int nr = to_sensor_dev_attr(attr)->index; \
178 	struct lm80_data *data = lm80_update_device(dev); \
179 	if (IS_ERR(data)) \
180 		return PTR_ERR(data); \
181 	return sprintf(buf, "%d\n", IN_FROM_REG(data->value[nr])); \
182 }
183 show_in(min, in_min)
184 show_in(max, in_max)
185 show_in(input, in)
186 
187 #define set_in(suffix, value, reg) \
188 static ssize_t set_in_##suffix(struct device *dev, \
189 	struct device_attribute *attr, const char *buf, size_t count) \
190 { \
191 	int nr = to_sensor_dev_attr(attr)->index; \
192 	struct lm80_data *data = dev_get_drvdata(dev); \
193 	struct i2c_client *client = data->client; \
194 	long val; \
195 	int err = kstrtol(buf, 10, &val); \
196 	if (err < 0) \
197 		return err; \
198 \
199 	mutex_lock(&data->update_lock);\
200 	data->value[nr] = IN_TO_REG(val); \
201 	lm80_write_value(client, reg(nr), data->value[nr]); \
202 	mutex_unlock(&data->update_lock);\
203 	return count; \
204 }
205 set_in(min, in_min, LM80_REG_IN_MIN)
206 set_in(max, in_max, LM80_REG_IN_MAX)
207 
208 #define show_fan(suffix, value) \
209 static ssize_t show_fan_##suffix(struct device *dev, \
210 	struct device_attribute *attr, char *buf) \
211 { \
212 	int nr = to_sensor_dev_attr(attr)->index; \
213 	struct lm80_data *data = lm80_update_device(dev); \
214 	if (IS_ERR(data)) \
215 		return PTR_ERR(data); \
216 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->value[nr], \
217 		       DIV_FROM_REG(data->fan_div[nr]))); \
218 }
219 show_fan(min, fan_min)
220 show_fan(input, fan)
221 
222 static ssize_t show_fan_div(struct device *dev, struct device_attribute *attr,
223 	char *buf)
224 {
225 	int nr = to_sensor_dev_attr(attr)->index;
226 	struct lm80_data *data = lm80_update_device(dev);
227 	if (IS_ERR(data))
228 		return PTR_ERR(data);
229 	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]));
230 }
231 
232 static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr,
233 	const char *buf, size_t count)
234 {
235 	int nr = to_sensor_dev_attr(attr)->index;
236 	struct lm80_data *data = dev_get_drvdata(dev);
237 	struct i2c_client *client = data->client;
238 	unsigned long val;
239 	int err = kstrtoul(buf, 10, &val);
240 	if (err < 0)
241 		return err;
242 
243 	mutex_lock(&data->update_lock);
244 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
245 	lm80_write_value(client, LM80_REG_FAN_MIN(nr + 1), data->fan_min[nr]);
246 	mutex_unlock(&data->update_lock);
247 	return count;
248 }
249 
250 /*
251  * Note: we save and restore the fan minimum here, because its value is
252  * determined in part by the fan divisor.  This follows the principle of
253  * least surprise; the user doesn't expect the fan minimum to change just
254  * because the divisor changed.
255  */
256 static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
257 	const char *buf, size_t count)
258 {
259 	int nr = to_sensor_dev_attr(attr)->index;
260 	struct lm80_data *data = dev_get_drvdata(dev);
261 	struct i2c_client *client = data->client;
262 	unsigned long min, val;
263 	u8 reg;
264 	int err = kstrtoul(buf, 10, &val);
265 	if (err < 0)
266 		return err;
267 
268 	/* Save fan_min */
269 	mutex_lock(&data->update_lock);
270 	min = FAN_FROM_REG(data->fan_min[nr],
271 			   DIV_FROM_REG(data->fan_div[nr]));
272 
273 	switch (val) {
274 	case 1:
275 		data->fan_div[nr] = 0;
276 		break;
277 	case 2:
278 		data->fan_div[nr] = 1;
279 		break;
280 	case 4:
281 		data->fan_div[nr] = 2;
282 		break;
283 	case 8:
284 		data->fan_div[nr] = 3;
285 		break;
286 	default:
287 		dev_err(dev,
288 			"fan_div value %ld not supported. Choose one of 1, 2, 4 or 8!\n",
289 			val);
290 		mutex_unlock(&data->update_lock);
291 		return -EINVAL;
292 	}
293 
294 	reg = (lm80_read_value(client, LM80_REG_FANDIV) & ~(3 << (2 * (nr + 1))))
295 	    | (data->fan_div[nr] << (2 * (nr + 1)));
296 	lm80_write_value(client, LM80_REG_FANDIV, reg);
297 
298 	/* Restore fan_min */
299 	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
300 	lm80_write_value(client, LM80_REG_FAN_MIN(nr + 1), data->fan_min[nr]);
301 	mutex_unlock(&data->update_lock);
302 
303 	return count;
304 }
305 
306 static ssize_t show_temp_input1(struct device *dev,
307 	struct device_attribute *attr, char *buf)
308 {
309 	struct lm80_data *data = lm80_update_device(dev);
310 	if (IS_ERR(data))
311 		return PTR_ERR(data);
312 	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp));
313 }
314 
315 #define show_temp(suffix, value) \
316 static ssize_t show_temp_##suffix(struct device *dev, \
317 	struct device_attribute *attr, char *buf) \
318 { \
319 	struct lm80_data *data = lm80_update_device(dev); \
320 	if (IS_ERR(data)) \
321 		return PTR_ERR(data); \
322 	return sprintf(buf, "%d\n", TEMP_LIMIT_FROM_REG(data->value)); \
323 }
324 show_temp(hot_max, temp_hot_max);
325 show_temp(hot_hyst, temp_hot_hyst);
326 show_temp(os_max, temp_os_max);
327 show_temp(os_hyst, temp_os_hyst);
328 
329 #define set_temp(suffix, value, reg) \
330 static ssize_t set_temp_##suffix(struct device *dev, \
331 	struct device_attribute *attr, const char *buf, size_t count) \
332 { \
333 	struct lm80_data *data = dev_get_drvdata(dev); \
334 	struct i2c_client *client = data->client; \
335 	long val; \
336 	int err = kstrtol(buf, 10, &val); \
337 	if (err < 0) \
338 		return err; \
339 \
340 	mutex_lock(&data->update_lock); \
341 	data->value = TEMP_LIMIT_TO_REG(val); \
342 	lm80_write_value(client, reg, data->value); \
343 	mutex_unlock(&data->update_lock); \
344 	return count; \
345 }
346 set_temp(hot_max, temp_hot_max, LM80_REG_TEMP_HOT_MAX);
347 set_temp(hot_hyst, temp_hot_hyst, LM80_REG_TEMP_HOT_HYST);
348 set_temp(os_max, temp_os_max, LM80_REG_TEMP_OS_MAX);
349 set_temp(os_hyst, temp_os_hyst, LM80_REG_TEMP_OS_HYST);
350 
351 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
352 			   char *buf)
353 {
354 	struct lm80_data *data = lm80_update_device(dev);
355 	if (IS_ERR(data))
356 		return PTR_ERR(data);
357 	return sprintf(buf, "%u\n", data->alarms);
358 }
359 
360 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
361 			  char *buf)
362 {
363 	int bitnr = to_sensor_dev_attr(attr)->index;
364 	struct lm80_data *data = lm80_update_device(dev);
365 	if (IS_ERR(data))
366 		return PTR_ERR(data);
367 	return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
368 }
369 
370 static SENSOR_DEVICE_ATTR(in0_min, S_IWUSR | S_IRUGO,
371 		show_in_min, set_in_min, 0);
372 static SENSOR_DEVICE_ATTR(in1_min, S_IWUSR | S_IRUGO,
373 		show_in_min, set_in_min, 1);
374 static SENSOR_DEVICE_ATTR(in2_min, S_IWUSR | S_IRUGO,
375 		show_in_min, set_in_min, 2);
376 static SENSOR_DEVICE_ATTR(in3_min, S_IWUSR | S_IRUGO,
377 		show_in_min, set_in_min, 3);
378 static SENSOR_DEVICE_ATTR(in4_min, S_IWUSR | S_IRUGO,
379 		show_in_min, set_in_min, 4);
380 static SENSOR_DEVICE_ATTR(in5_min, S_IWUSR | S_IRUGO,
381 		show_in_min, set_in_min, 5);
382 static SENSOR_DEVICE_ATTR(in6_min, S_IWUSR | S_IRUGO,
383 		show_in_min, set_in_min, 6);
384 static SENSOR_DEVICE_ATTR(in0_max, S_IWUSR | S_IRUGO,
385 		show_in_max, set_in_max, 0);
386 static SENSOR_DEVICE_ATTR(in1_max, S_IWUSR | S_IRUGO,
387 		show_in_max, set_in_max, 1);
388 static SENSOR_DEVICE_ATTR(in2_max, S_IWUSR | S_IRUGO,
389 		show_in_max, set_in_max, 2);
390 static SENSOR_DEVICE_ATTR(in3_max, S_IWUSR | S_IRUGO,
391 		show_in_max, set_in_max, 3);
392 static SENSOR_DEVICE_ATTR(in4_max, S_IWUSR | S_IRUGO,
393 		show_in_max, set_in_max, 4);
394 static SENSOR_DEVICE_ATTR(in5_max, S_IWUSR | S_IRUGO,
395 		show_in_max, set_in_max, 5);
396 static SENSOR_DEVICE_ATTR(in6_max, S_IWUSR | S_IRUGO,
397 		show_in_max, set_in_max, 6);
398 static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, show_in_input, NULL, 0);
399 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_in_input, NULL, 1);
400 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_in_input, NULL, 2);
401 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_in_input, NULL, 3);
402 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_in_input, NULL, 4);
403 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, show_in_input, NULL, 5);
404 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, show_in_input, NULL, 6);
405 static SENSOR_DEVICE_ATTR(fan1_min, S_IWUSR | S_IRUGO,
406 		show_fan_min, set_fan_min, 0);
407 static SENSOR_DEVICE_ATTR(fan2_min, S_IWUSR | S_IRUGO,
408 		show_fan_min, set_fan_min, 1);
409 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan_input, NULL, 0);
410 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan_input, NULL, 1);
411 static SENSOR_DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO,
412 		show_fan_div, set_fan_div, 0);
413 static SENSOR_DEVICE_ATTR(fan2_div, S_IWUSR | S_IRUGO,
414 		show_fan_div, set_fan_div, 1);
415 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
416 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_hot_max,
417 	set_temp_hot_max);
418 static DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_hot_hyst,
419 	set_temp_hot_hyst);
420 static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp_os_max,
421 	set_temp_os_max);
422 static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_os_hyst,
423 	set_temp_os_hyst);
424 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
425 static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 0);
426 static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 1);
427 static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, show_alarm, NULL, 2);
428 static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, show_alarm, NULL, 3);
429 static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, show_alarm, NULL, 4);
430 static SENSOR_DEVICE_ATTR(in5_alarm, S_IRUGO, show_alarm, NULL, 5);
431 static SENSOR_DEVICE_ATTR(in6_alarm, S_IRUGO, show_alarm, NULL, 6);
432 static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_alarm, NULL, 10);
433 static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_alarm, NULL, 11);
434 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 8);
435 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 13);
436 
437 /*
438  * Real code
439  */
440 
441 static struct attribute *lm80_attrs[] = {
442 	&sensor_dev_attr_in0_min.dev_attr.attr,
443 	&sensor_dev_attr_in1_min.dev_attr.attr,
444 	&sensor_dev_attr_in2_min.dev_attr.attr,
445 	&sensor_dev_attr_in3_min.dev_attr.attr,
446 	&sensor_dev_attr_in4_min.dev_attr.attr,
447 	&sensor_dev_attr_in5_min.dev_attr.attr,
448 	&sensor_dev_attr_in6_min.dev_attr.attr,
449 	&sensor_dev_attr_in0_max.dev_attr.attr,
450 	&sensor_dev_attr_in1_max.dev_attr.attr,
451 	&sensor_dev_attr_in2_max.dev_attr.attr,
452 	&sensor_dev_attr_in3_max.dev_attr.attr,
453 	&sensor_dev_attr_in4_max.dev_attr.attr,
454 	&sensor_dev_attr_in5_max.dev_attr.attr,
455 	&sensor_dev_attr_in6_max.dev_attr.attr,
456 	&sensor_dev_attr_in0_input.dev_attr.attr,
457 	&sensor_dev_attr_in1_input.dev_attr.attr,
458 	&sensor_dev_attr_in2_input.dev_attr.attr,
459 	&sensor_dev_attr_in3_input.dev_attr.attr,
460 	&sensor_dev_attr_in4_input.dev_attr.attr,
461 	&sensor_dev_attr_in5_input.dev_attr.attr,
462 	&sensor_dev_attr_in6_input.dev_attr.attr,
463 	&sensor_dev_attr_fan1_min.dev_attr.attr,
464 	&sensor_dev_attr_fan2_min.dev_attr.attr,
465 	&sensor_dev_attr_fan1_input.dev_attr.attr,
466 	&sensor_dev_attr_fan2_input.dev_attr.attr,
467 	&sensor_dev_attr_fan1_div.dev_attr.attr,
468 	&sensor_dev_attr_fan2_div.dev_attr.attr,
469 	&dev_attr_temp1_input.attr,
470 	&dev_attr_temp1_max.attr,
471 	&dev_attr_temp1_max_hyst.attr,
472 	&dev_attr_temp1_crit.attr,
473 	&dev_attr_temp1_crit_hyst.attr,
474 	&dev_attr_alarms.attr,
475 	&sensor_dev_attr_in0_alarm.dev_attr.attr,
476 	&sensor_dev_attr_in1_alarm.dev_attr.attr,
477 	&sensor_dev_attr_in2_alarm.dev_attr.attr,
478 	&sensor_dev_attr_in3_alarm.dev_attr.attr,
479 	&sensor_dev_attr_in4_alarm.dev_attr.attr,
480 	&sensor_dev_attr_in5_alarm.dev_attr.attr,
481 	&sensor_dev_attr_in6_alarm.dev_attr.attr,
482 	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
483 	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
484 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
485 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
486 	NULL
487 };
488 ATTRIBUTE_GROUPS(lm80);
489 
490 /* Return 0 if detection is successful, -ENODEV otherwise */
491 static int lm80_detect(struct i2c_client *client, struct i2c_board_info *info)
492 {
493 	struct i2c_adapter *adapter = client->adapter;
494 	int i, cur, man_id, dev_id;
495 	const char *name = NULL;
496 
497 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
498 		return -ENODEV;
499 
500 	/* First check for unused bits, common to both chip types */
501 	if ((lm80_read_value(client, LM80_REG_ALARM2) & 0xc0)
502 	 || (lm80_read_value(client, LM80_REG_CONFIG) & 0x80))
503 		return -ENODEV;
504 
505 	/*
506 	 * The LM96080 has manufacturer and stepping/die rev registers so we
507 	 * can just check that. The LM80 does not have such registers so we
508 	 * have to use a more expensive trick.
509 	 */
510 	man_id = lm80_read_value(client, LM96080_REG_MAN_ID);
511 	dev_id = lm80_read_value(client, LM96080_REG_DEV_ID);
512 	if (man_id == 0x01 && dev_id == 0x08) {
513 		/* Check more unused bits for confirmation */
514 		if (lm80_read_value(client, LM96080_REG_CONV_RATE) & 0xfe)
515 			return -ENODEV;
516 
517 		name = "lm96080";
518 	} else {
519 		/* Check 6-bit addressing */
520 		for (i = 0x2a; i <= 0x3d; i++) {
521 			cur = i2c_smbus_read_byte_data(client, i);
522 			if ((i2c_smbus_read_byte_data(client, i + 0x40) != cur)
523 			 || (i2c_smbus_read_byte_data(client, i + 0x80) != cur)
524 			 || (i2c_smbus_read_byte_data(client, i + 0xc0) != cur))
525 				return -ENODEV;
526 		}
527 
528 		name = "lm80";
529 	}
530 
531 	strlcpy(info->type, name, I2C_NAME_SIZE);
532 
533 	return 0;
534 }
535 
536 static int lm80_probe(struct i2c_client *client,
537 		      const struct i2c_device_id *id)
538 {
539 	struct device *dev = &client->dev;
540 	struct device *hwmon_dev;
541 	struct lm80_data *data;
542 
543 	data = devm_kzalloc(dev, sizeof(struct lm80_data), GFP_KERNEL);
544 	if (!data)
545 		return -ENOMEM;
546 
547 	data->client = client;
548 	mutex_init(&data->update_lock);
549 
550 	/* Initialize the LM80 chip */
551 	lm80_init_client(client);
552 
553 	/* A few vars need to be filled upon startup */
554 	data->fan_min[0] = lm80_read_value(client, LM80_REG_FAN_MIN(1));
555 	data->fan_min[1] = lm80_read_value(client, LM80_REG_FAN_MIN(2));
556 
557 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
558 							   data, lm80_groups);
559 
560 	return PTR_ERR_OR_ZERO(hwmon_dev);
561 }
562 
563 static int lm80_read_value(struct i2c_client *client, u8 reg)
564 {
565 	return i2c_smbus_read_byte_data(client, reg);
566 }
567 
568 static int lm80_write_value(struct i2c_client *client, u8 reg, u8 value)
569 {
570 	return i2c_smbus_write_byte_data(client, reg, value);
571 }
572 
573 /* Called when we have found a new LM80. */
574 static void lm80_init_client(struct i2c_client *client)
575 {
576 	/*
577 	 * Reset all except Watchdog values and last conversion values
578 	 * This sets fan-divs to 2, among others. This makes most other
579 	 * initializations unnecessary
580 	 */
581 	lm80_write_value(client, LM80_REG_CONFIG, 0x80);
582 	/* Set 11-bit temperature resolution */
583 	lm80_write_value(client, LM80_REG_RES, 0x08);
584 
585 	/* Start monitoring */
586 	lm80_write_value(client, LM80_REG_CONFIG, 0x01);
587 }
588 
589 static struct lm80_data *lm80_update_device(struct device *dev)
590 {
591 	struct lm80_data *data = dev_get_drvdata(dev);
592 	struct i2c_client *client = data->client;
593 	int i;
594 	int rv;
595 	int prev_rv;
596 	struct lm80_data *ret = data;
597 
598 	mutex_lock(&data->update_lock);
599 
600 	if (data->error)
601 		lm80_init_client(client);
602 
603 	if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
604 		dev_dbg(dev, "Starting lm80 update\n");
605 		for (i = 0; i <= 6; i++) {
606 			rv = lm80_read_value(client, LM80_REG_IN(i));
607 			if (rv < 0)
608 				goto abort;
609 			data->in[i] = rv;
610 
611 			rv = lm80_read_value(client, LM80_REG_IN_MIN(i));
612 			if (rv < 0)
613 				goto abort;
614 			data->in_min[i] = rv;
615 
616 			rv = lm80_read_value(client, LM80_REG_IN_MAX(i));
617 			if (rv < 0)
618 				goto abort;
619 			data->in_max[i] = rv;
620 		}
621 
622 		rv = lm80_read_value(client, LM80_REG_FAN1);
623 		if (rv < 0)
624 			goto abort;
625 		data->fan[0] = rv;
626 
627 		rv = lm80_read_value(client, LM80_REG_FAN_MIN(1));
628 		if (rv < 0)
629 			goto abort;
630 		data->fan_min[0] = rv;
631 
632 		rv = lm80_read_value(client, LM80_REG_FAN2);
633 		if (rv < 0)
634 			goto abort;
635 		data->fan[1] = rv;
636 
637 		rv = lm80_read_value(client, LM80_REG_FAN_MIN(2));
638 		if (rv < 0)
639 			goto abort;
640 		data->fan_min[1] = rv;
641 
642 		prev_rv = rv = lm80_read_value(client, LM80_REG_TEMP);
643 		if (rv < 0)
644 			goto abort;
645 		rv = lm80_read_value(client, LM80_REG_RES);
646 		if (rv < 0)
647 			goto abort;
648 		data->temp = (prev_rv << 8) | (rv & 0xf0);
649 
650 		rv = lm80_read_value(client, LM80_REG_TEMP_OS_MAX);
651 		if (rv < 0)
652 			goto abort;
653 		data->temp_os_max = rv;
654 
655 		rv = lm80_read_value(client, LM80_REG_TEMP_OS_HYST);
656 		if (rv < 0)
657 			goto abort;
658 		data->temp_os_hyst = rv;
659 
660 		rv = lm80_read_value(client, LM80_REG_TEMP_HOT_MAX);
661 		if (rv < 0)
662 			goto abort;
663 		data->temp_hot_max = rv;
664 
665 		rv = lm80_read_value(client, LM80_REG_TEMP_HOT_HYST);
666 		if (rv < 0)
667 			goto abort;
668 		data->temp_hot_hyst = rv;
669 
670 		rv = lm80_read_value(client, LM80_REG_FANDIV);
671 		if (rv < 0)
672 			goto abort;
673 		data->fan_div[0] = (rv >> 2) & 0x03;
674 		data->fan_div[1] = (rv >> 4) & 0x03;
675 
676 		prev_rv = rv = lm80_read_value(client, LM80_REG_ALARM1);
677 		if (rv < 0)
678 			goto abort;
679 		rv = lm80_read_value(client, LM80_REG_ALARM2);
680 		if (rv < 0)
681 			goto abort;
682 		data->alarms = prev_rv + (rv << 8);
683 
684 		data->last_updated = jiffies;
685 		data->valid = 1;
686 		data->error = 0;
687 	}
688 	goto done;
689 
690 abort:
691 	ret = ERR_PTR(rv);
692 	data->valid = 0;
693 	data->error = 1;
694 
695 done:
696 	mutex_unlock(&data->update_lock);
697 
698 	return ret;
699 }
700 
701 module_i2c_driver(lm80_driver);
702 
703 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
704 	"Philip Edelbrock <phil@netroedge.com>");
705 MODULE_DESCRIPTION("LM80 driver");
706 MODULE_LICENSE("GPL");
707