xref: /openbmc/linux/drivers/hwmon/lm90.c (revision 367b8112)
1 /*
2  * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
3  *          monitoring
4  * Copyright (C) 2003-2008  Jean Delvare <khali@linux-fr.org>
5  *
6  * Based on the lm83 driver. The LM90 is a sensor chip made by National
7  * Semiconductor. It reports up to two temperatures (its own plus up to
8  * one external one) with a 0.125 deg resolution (1 deg for local
9  * temperature) and a 3-4 deg accuracy.
10  *
11  * This driver also supports the LM89 and LM99, two other sensor chips
12  * made by National Semiconductor. Both have an increased remote
13  * temperature measurement accuracy (1 degree), and the LM99
14  * additionally shifts remote temperatures (measured and limits) by 16
15  * degrees, which allows for higher temperatures measurement.
16  * Note that there is no way to differentiate between both chips.
17  * When device is auto-detected, the driver will assume an LM99.
18  *
19  * This driver also supports the LM86, another sensor chip made by
20  * National Semiconductor. It is exactly similar to the LM90 except it
21  * has a higher accuracy.
22  *
23  * This driver also supports the ADM1032, a sensor chip made by Analog
24  * Devices. That chip is similar to the LM90, with a few differences
25  * that are not handled by this driver. Among others, it has a higher
26  * accuracy than the LM90, much like the LM86 does.
27  *
28  * This driver also supports the MAX6657, MAX6658 and MAX6659 sensor
29  * chips made by Maxim. These chips are similar to the LM86.
30  * Note that there is no easy way to differentiate between the three
31  * variants. The extra address and features of the MAX6659 are not
32  * supported by this driver. These chips lack the remote temperature
33  * offset feature.
34  *
35  * This driver also supports the MAX6646, MAX6647 and MAX6649 chips
36  * made by Maxim.  These are again similar to the LM86, but they use
37  * unsigned temperature values and can report temperatures from 0 to
38  * 145 degrees.
39  *
40  * This driver also supports the MAX6680 and MAX6681, two other sensor
41  * chips made by Maxim. These are quite similar to the other Maxim
42  * chips. The MAX6680 and MAX6681 only differ in the pinout so they can
43  * be treated identically.
44  *
45  * This driver also supports the ADT7461 chip from Analog Devices.
46  * It's supported in both compatibility and extended mode. It is mostly
47  * compatible with LM90 except for a data format difference for the
48  * temperature value registers.
49  *
50  * Since the LM90 was the first chipset supported by this driver, most
51  * comments will refer to this chipset, but are actually general and
52  * concern all supported chipsets, unless mentioned otherwise.
53  *
54  * This program is free software; you can redistribute it and/or modify
55  * it under the terms of the GNU General Public License as published by
56  * the Free Software Foundation; either version 2 of the License, or
57  * (at your option) any later version.
58  *
59  * This program is distributed in the hope that it will be useful,
60  * but WITHOUT ANY WARRANTY; without even the implied warranty of
61  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
62  * GNU General Public License for more details.
63  *
64  * You should have received a copy of the GNU General Public License
65  * along with this program; if not, write to the Free Software
66  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
67  */
68 
69 #include <linux/module.h>
70 #include <linux/init.h>
71 #include <linux/slab.h>
72 #include <linux/jiffies.h>
73 #include <linux/i2c.h>
74 #include <linux/hwmon-sysfs.h>
75 #include <linux/hwmon.h>
76 #include <linux/err.h>
77 #include <linux/mutex.h>
78 #include <linux/sysfs.h>
79 
80 /*
81  * Addresses to scan
82  * Address is fully defined internally and cannot be changed except for
83  * MAX6659, MAX6680 and MAX6681.
84  * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, MAX6649, MAX6657
85  * and MAX6658 have address 0x4c.
86  * ADM1032-2, ADT7461-2, LM89-1, LM99-1 and MAX6646 have address 0x4d.
87  * MAX6647 has address 0x4e.
88  * MAX6659 can have address 0x4c, 0x4d or 0x4e (unsupported).
89  * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
90  * 0x4c, 0x4d or 0x4e.
91  */
92 
93 static const unsigned short normal_i2c[] = {
94 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
95 
96 /*
97  * Insmod parameters
98  */
99 
100 I2C_CLIENT_INSMOD_8(lm90, adm1032, lm99, lm86, max6657, adt7461, max6680,
101 		    max6646);
102 
103 /*
104  * The LM90 registers
105  */
106 
107 #define LM90_REG_R_MAN_ID		0xFE
108 #define LM90_REG_R_CHIP_ID		0xFF
109 #define LM90_REG_R_CONFIG1		0x03
110 #define LM90_REG_W_CONFIG1		0x09
111 #define LM90_REG_R_CONFIG2		0xBF
112 #define LM90_REG_W_CONFIG2		0xBF
113 #define LM90_REG_R_CONVRATE		0x04
114 #define LM90_REG_W_CONVRATE		0x0A
115 #define LM90_REG_R_STATUS		0x02
116 #define LM90_REG_R_LOCAL_TEMP		0x00
117 #define LM90_REG_R_LOCAL_HIGH		0x05
118 #define LM90_REG_W_LOCAL_HIGH		0x0B
119 #define LM90_REG_R_LOCAL_LOW		0x06
120 #define LM90_REG_W_LOCAL_LOW		0x0C
121 #define LM90_REG_R_LOCAL_CRIT		0x20
122 #define LM90_REG_W_LOCAL_CRIT		0x20
123 #define LM90_REG_R_REMOTE_TEMPH		0x01
124 #define LM90_REG_R_REMOTE_TEMPL		0x10
125 #define LM90_REG_R_REMOTE_OFFSH		0x11
126 #define LM90_REG_W_REMOTE_OFFSH		0x11
127 #define LM90_REG_R_REMOTE_OFFSL		0x12
128 #define LM90_REG_W_REMOTE_OFFSL		0x12
129 #define LM90_REG_R_REMOTE_HIGHH		0x07
130 #define LM90_REG_W_REMOTE_HIGHH		0x0D
131 #define LM90_REG_R_REMOTE_HIGHL		0x13
132 #define LM90_REG_W_REMOTE_HIGHL		0x13
133 #define LM90_REG_R_REMOTE_LOWH		0x08
134 #define LM90_REG_W_REMOTE_LOWH		0x0E
135 #define LM90_REG_R_REMOTE_LOWL		0x14
136 #define LM90_REG_W_REMOTE_LOWL		0x14
137 #define LM90_REG_R_REMOTE_CRIT		0x19
138 #define LM90_REG_W_REMOTE_CRIT		0x19
139 #define LM90_REG_R_TCRIT_HYST		0x21
140 #define LM90_REG_W_TCRIT_HYST		0x21
141 
142 /* MAX6646/6647/6649/6657/6658/6659 registers */
143 
144 #define MAX6657_REG_R_LOCAL_TEMPL	0x11
145 
146 /*
147  * Device flags
148  */
149 #define LM90_FLAG_ADT7461_EXT		0x01	/* ADT7461 extended mode */
150 
151 /*
152  * Functions declaration
153  */
154 
155 static int lm90_detect(struct i2c_client *client, int kind,
156 		       struct i2c_board_info *info);
157 static int lm90_probe(struct i2c_client *client,
158 		      const struct i2c_device_id *id);
159 static void lm90_init_client(struct i2c_client *client);
160 static int lm90_remove(struct i2c_client *client);
161 static struct lm90_data *lm90_update_device(struct device *dev);
162 
163 /*
164  * Driver data (common to all clients)
165  */
166 
167 static const struct i2c_device_id lm90_id[] = {
168 	{ "adm1032", adm1032 },
169 	{ "adt7461", adt7461 },
170 	{ "lm90", lm90 },
171 	{ "lm86", lm86 },
172 	{ "lm89", lm86 },
173 	{ "lm99", lm99 },
174 	{ "max6646", max6646 },
175 	{ "max6647", max6646 },
176 	{ "max6649", max6646 },
177 	{ "max6657", max6657 },
178 	{ "max6658", max6657 },
179 	{ "max6659", max6657 },
180 	{ "max6680", max6680 },
181 	{ "max6681", max6680 },
182 	{ }
183 };
184 MODULE_DEVICE_TABLE(i2c, lm90_id);
185 
186 static struct i2c_driver lm90_driver = {
187 	.class		= I2C_CLASS_HWMON,
188 	.driver = {
189 		.name	= "lm90",
190 	},
191 	.probe		= lm90_probe,
192 	.remove		= lm90_remove,
193 	.id_table	= lm90_id,
194 	.detect		= lm90_detect,
195 	.address_data	= &addr_data,
196 };
197 
198 /*
199  * Client data (each client gets its own)
200  */
201 
202 struct lm90_data {
203 	struct device *hwmon_dev;
204 	struct mutex update_lock;
205 	char valid; /* zero until following fields are valid */
206 	unsigned long last_updated; /* in jiffies */
207 	int kind;
208 	int flags;
209 
210 	/* registers values */
211 	s8 temp8[4];	/* 0: local low limit
212 			   1: local high limit
213 			   2: local critical limit
214 			   3: remote critical limit */
215 	s16 temp11[5];	/* 0: remote input
216 			   1: remote low limit
217 			   2: remote high limit
218 			   3: remote offset (except max6646 and max6657)
219 			   4: local input */
220 	u8 temp_hyst;
221 	u8 alarms; /* bitvector */
222 };
223 
224 /*
225  * Conversions
226  * For local temperatures and limits, critical limits and the hysteresis
227  * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
228  * For remote temperatures and limits, it uses signed 11-bit values with
229  * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.  Some
230  * Maxim chips use unsigned values.
231  */
232 
233 static inline int temp_from_s8(s8 val)
234 {
235 	return val * 1000;
236 }
237 
238 static inline int temp_from_u8(u8 val)
239 {
240 	return val * 1000;
241 }
242 
243 static inline int temp_from_s16(s16 val)
244 {
245 	return val / 32 * 125;
246 }
247 
248 static inline int temp_from_u16(u16 val)
249 {
250 	return val / 32 * 125;
251 }
252 
253 static s8 temp_to_s8(long val)
254 {
255 	if (val <= -128000)
256 		return -128;
257 	if (val >= 127000)
258 		return 127;
259 	if (val < 0)
260 		return (val - 500) / 1000;
261 	return (val + 500) / 1000;
262 }
263 
264 static u8 temp_to_u8(long val)
265 {
266 	if (val <= 0)
267 		return 0;
268 	if (val >= 255000)
269 		return 255;
270 	return (val + 500) / 1000;
271 }
272 
273 static s16 temp_to_s16(long val)
274 {
275 	if (val <= -128000)
276 		return 0x8000;
277 	if (val >= 127875)
278 		return 0x7FE0;
279 	if (val < 0)
280 		return (val - 62) / 125 * 32;
281 	return (val + 62) / 125 * 32;
282 }
283 
284 static u8 hyst_to_reg(long val)
285 {
286 	if (val <= 0)
287 		return 0;
288 	if (val >= 30500)
289 		return 31;
290 	return (val + 500) / 1000;
291 }
292 
293 /*
294  * ADT7461 in compatibility mode is almost identical to LM90 except that
295  * attempts to write values that are outside the range 0 < temp < 127 are
296  * treated as the boundary value.
297  *
298  * ADT7461 in "extended mode" operation uses unsigned integers offset by
299  * 64 (e.g., 0 -> -64 degC).  The range is restricted to -64..191 degC.
300  */
301 static inline int temp_from_u8_adt7461(struct lm90_data *data, u8 val)
302 {
303 	if (data->flags & LM90_FLAG_ADT7461_EXT)
304 		return (val - 64) * 1000;
305 	else
306 		return temp_from_s8(val);
307 }
308 
309 static inline int temp_from_u16_adt7461(struct lm90_data *data, u16 val)
310 {
311 	if (data->flags & LM90_FLAG_ADT7461_EXT)
312 		return (val - 0x4000) / 64 * 250;
313 	else
314 		return temp_from_s16(val);
315 }
316 
317 static u8 temp_to_u8_adt7461(struct lm90_data *data, long val)
318 {
319 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
320 		if (val <= -64000)
321 			return 0;
322 		if (val >= 191000)
323 			return 0xFF;
324 		return (val + 500 + 64000) / 1000;
325 	} else {
326 		if (val <= 0)
327 			return 0;
328 		if (val >= 127000)
329 			return 127;
330 		return (val + 500) / 1000;
331 	}
332 }
333 
334 static u16 temp_to_u16_adt7461(struct lm90_data *data, long val)
335 {
336 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
337 		if (val <= -64000)
338 			return 0;
339 		if (val >= 191750)
340 			return 0xFFC0;
341 		return (val + 64000 + 125) / 250 * 64;
342 	} else {
343 		if (val <= 0)
344 			return 0;
345 		if (val >= 127750)
346 			return 0x7FC0;
347 		return (val + 125) / 250 * 64;
348 	}
349 }
350 
351 /*
352  * Sysfs stuff
353  */
354 
355 static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
356 			  char *buf)
357 {
358 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
359 	struct lm90_data *data = lm90_update_device(dev);
360 	int temp;
361 
362 	if (data->kind == adt7461)
363 		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
364 	else if (data->kind == max6646)
365 		temp = temp_from_u8(data->temp8[attr->index]);
366 	else
367 		temp = temp_from_s8(data->temp8[attr->index]);
368 
369 	/* +16 degrees offset for temp2 for the LM99 */
370 	if (data->kind == lm99 && attr->index == 3)
371 		temp += 16000;
372 
373 	return sprintf(buf, "%d\n", temp);
374 }
375 
376 static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
377 			 const char *buf, size_t count)
378 {
379 	static const u8 reg[4] = {
380 		LM90_REG_W_LOCAL_LOW,
381 		LM90_REG_W_LOCAL_HIGH,
382 		LM90_REG_W_LOCAL_CRIT,
383 		LM90_REG_W_REMOTE_CRIT,
384 	};
385 
386 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
387 	struct i2c_client *client = to_i2c_client(dev);
388 	struct lm90_data *data = i2c_get_clientdata(client);
389 	long val = simple_strtol(buf, NULL, 10);
390 	int nr = attr->index;
391 
392 	/* +16 degrees offset for temp2 for the LM99 */
393 	if (data->kind == lm99 && attr->index == 3)
394 		val -= 16000;
395 
396 	mutex_lock(&data->update_lock);
397 	if (data->kind == adt7461)
398 		data->temp8[nr] = temp_to_u8_adt7461(data, val);
399 	else if (data->kind == max6646)
400 		data->temp8[nr] = temp_to_u8(val);
401 	else
402 		data->temp8[nr] = temp_to_s8(val);
403 	i2c_smbus_write_byte_data(client, reg[nr], data->temp8[nr]);
404 	mutex_unlock(&data->update_lock);
405 	return count;
406 }
407 
408 static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
409 			   char *buf)
410 {
411 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
412 	struct lm90_data *data = lm90_update_device(dev);
413 	int temp;
414 
415 	if (data->kind == adt7461)
416 		temp = temp_from_u16_adt7461(data, data->temp11[attr->index]);
417 	else if (data->kind == max6646)
418 		temp = temp_from_u16(data->temp11[attr->index]);
419 	else
420 		temp = temp_from_s16(data->temp11[attr->index]);
421 
422 	/* +16 degrees offset for temp2 for the LM99 */
423 	if (data->kind == lm99 &&  attr->index <= 2)
424 		temp += 16000;
425 
426 	return sprintf(buf, "%d\n", temp);
427 }
428 
429 static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
430 			  const char *buf, size_t count)
431 {
432 	static const u8 reg[6] = {
433 		LM90_REG_W_REMOTE_LOWH,
434 		LM90_REG_W_REMOTE_LOWL,
435 		LM90_REG_W_REMOTE_HIGHH,
436 		LM90_REG_W_REMOTE_HIGHL,
437 		LM90_REG_W_REMOTE_OFFSH,
438 		LM90_REG_W_REMOTE_OFFSL,
439 	};
440 
441 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
442 	struct i2c_client *client = to_i2c_client(dev);
443 	struct lm90_data *data = i2c_get_clientdata(client);
444 	long val = simple_strtol(buf, NULL, 10);
445 	int nr = attr->index;
446 
447 	/* +16 degrees offset for temp2 for the LM99 */
448 	if (data->kind == lm99 && attr->index <= 2)
449 		val -= 16000;
450 
451 	mutex_lock(&data->update_lock);
452 	if (data->kind == adt7461)
453 		data->temp11[nr] = temp_to_u16_adt7461(data, val);
454 	else if (data->kind == max6657 || data->kind == max6680)
455 		data->temp11[nr] = temp_to_s8(val) << 8;
456 	else if (data->kind == max6646)
457 		data->temp11[nr] = temp_to_u8(val) << 8;
458 	else
459 		data->temp11[nr] = temp_to_s16(val);
460 
461 	i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
462 				  data->temp11[nr] >> 8);
463 	if (data->kind != max6657 && data->kind != max6680
464 	    && data->kind != max6646)
465 		i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
466 					  data->temp11[nr] & 0xff);
467 	mutex_unlock(&data->update_lock);
468 	return count;
469 }
470 
471 static ssize_t show_temphyst(struct device *dev, struct device_attribute *devattr,
472 			     char *buf)
473 {
474 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
475 	struct lm90_data *data = lm90_update_device(dev);
476 	int temp;
477 
478 	if (data->kind == adt7461)
479 		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
480 	else if (data->kind == max6646)
481 		temp = temp_from_u8(data->temp8[attr->index]);
482 	else
483 		temp = temp_from_s8(data->temp8[attr->index]);
484 
485 	/* +16 degrees offset for temp2 for the LM99 */
486 	if (data->kind == lm99 && attr->index == 3)
487 		temp += 16000;
488 
489 	return sprintf(buf, "%d\n", temp - temp_from_s8(data->temp_hyst));
490 }
491 
492 static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
493 			    const char *buf, size_t count)
494 {
495 	struct i2c_client *client = to_i2c_client(dev);
496 	struct lm90_data *data = i2c_get_clientdata(client);
497 	long val = simple_strtol(buf, NULL, 10);
498 	int temp;
499 
500 	mutex_lock(&data->update_lock);
501 	if (data->kind == adt7461)
502 		temp = temp_from_u8_adt7461(data, data->temp8[2]);
503 	else if (data->kind == max6646)
504 		temp = temp_from_u8(data->temp8[2]);
505 	else
506 		temp = temp_from_s8(data->temp8[2]);
507 
508 	data->temp_hyst = hyst_to_reg(temp - val);
509 	i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
510 				  data->temp_hyst);
511 	mutex_unlock(&data->update_lock);
512 	return count;
513 }
514 
515 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
516 			   char *buf)
517 {
518 	struct lm90_data *data = lm90_update_device(dev);
519 	return sprintf(buf, "%d\n", data->alarms);
520 }
521 
522 static ssize_t show_alarm(struct device *dev, struct device_attribute
523 			  *devattr, char *buf)
524 {
525 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
526 	struct lm90_data *data = lm90_update_device(dev);
527 	int bitnr = attr->index;
528 
529 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
530 }
531 
532 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp11, NULL, 4);
533 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp11, NULL, 0);
534 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
535 	set_temp8, 0);
536 static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
537 	set_temp11, 1);
538 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
539 	set_temp8, 1);
540 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
541 	set_temp11, 2);
542 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
543 	set_temp8, 2);
544 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
545 	set_temp8, 3);
546 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
547 	set_temphyst, 2);
548 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 3);
549 static SENSOR_DEVICE_ATTR(temp2_offset, S_IWUSR | S_IRUGO, show_temp11,
550 	set_temp11, 3);
551 
552 /* Individual alarm files */
553 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
554 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
555 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
556 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
557 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
558 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 5);
559 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
560 /* Raw alarm file for compatibility */
561 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
562 
563 static struct attribute *lm90_attributes[] = {
564 	&sensor_dev_attr_temp1_input.dev_attr.attr,
565 	&sensor_dev_attr_temp2_input.dev_attr.attr,
566 	&sensor_dev_attr_temp1_min.dev_attr.attr,
567 	&sensor_dev_attr_temp2_min.dev_attr.attr,
568 	&sensor_dev_attr_temp1_max.dev_attr.attr,
569 	&sensor_dev_attr_temp2_max.dev_attr.attr,
570 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
571 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
572 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
573 	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
574 
575 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
576 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
577 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
578 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
579 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
580 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
581 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
582 	&dev_attr_alarms.attr,
583 	NULL
584 };
585 
586 static const struct attribute_group lm90_group = {
587 	.attrs = lm90_attributes,
588 };
589 
590 /* pec used for ADM1032 only */
591 static ssize_t show_pec(struct device *dev, struct device_attribute *dummy,
592 			char *buf)
593 {
594 	struct i2c_client *client = to_i2c_client(dev);
595 	return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
596 }
597 
598 static ssize_t set_pec(struct device *dev, struct device_attribute *dummy,
599 		       const char *buf, size_t count)
600 {
601 	struct i2c_client *client = to_i2c_client(dev);
602 	long val = simple_strtol(buf, NULL, 10);
603 
604 	switch (val) {
605 	case 0:
606 		client->flags &= ~I2C_CLIENT_PEC;
607 		break;
608 	case 1:
609 		client->flags |= I2C_CLIENT_PEC;
610 		break;
611 	default:
612 		return -EINVAL;
613 	}
614 
615 	return count;
616 }
617 
618 static DEVICE_ATTR(pec, S_IWUSR | S_IRUGO, show_pec, set_pec);
619 
620 /*
621  * Real code
622  */
623 
624 /* The ADM1032 supports PEC but not on write byte transactions, so we need
625    to explicitly ask for a transaction without PEC. */
626 static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value)
627 {
628 	return i2c_smbus_xfer(client->adapter, client->addr,
629 			      client->flags & ~I2C_CLIENT_PEC,
630 			      I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
631 }
632 
633 /* It is assumed that client->update_lock is held (unless we are in
634    detection or initialization steps). This matters when PEC is enabled,
635    because we don't want the address pointer to change between the write
636    byte and the read byte transactions. */
637 static int lm90_read_reg(struct i2c_client* client, u8 reg, u8 *value)
638 {
639 	int err;
640 
641  	if (client->flags & I2C_CLIENT_PEC) {
642  		err = adm1032_write_byte(client, reg);
643  		if (err >= 0)
644  			err = i2c_smbus_read_byte(client);
645  	} else
646  		err = i2c_smbus_read_byte_data(client, reg);
647 
648 	if (err < 0) {
649 		dev_warn(&client->dev, "Register %#02x read failed (%d)\n",
650 			 reg, err);
651 		return err;
652 	}
653 	*value = err;
654 
655 	return 0;
656 }
657 
658 /* Return 0 if detection is successful, -ENODEV otherwise */
659 static int lm90_detect(struct i2c_client *new_client, int kind,
660 		       struct i2c_board_info *info)
661 {
662 	struct i2c_adapter *adapter = new_client->adapter;
663 	int address = new_client->addr;
664 	const char *name = "";
665 
666 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
667 		return -ENODEV;
668 
669 	/*
670 	 * Now we do the remaining detection. A negative kind means that
671 	 * the driver was loaded with no force parameter (default), so we
672 	 * must both detect and identify the chip. A zero kind means that
673 	 * the driver was loaded with the force parameter, the detection
674 	 * step shall be skipped. A positive kind means that the driver
675 	 * was loaded with the force parameter and a given kind of chip is
676 	 * requested, so both the detection and the identification steps
677 	 * are skipped.
678 	 */
679 
680 	/* Default to an LM90 if forced */
681 	if (kind == 0)
682 		kind = lm90;
683 
684 	if (kind < 0) { /* detection and identification */
685 		int man_id, chip_id, reg_config1, reg_convrate;
686 
687 		if ((man_id = i2c_smbus_read_byte_data(new_client,
688 						LM90_REG_R_MAN_ID)) < 0
689 		 || (chip_id = i2c_smbus_read_byte_data(new_client,
690 						LM90_REG_R_CHIP_ID)) < 0
691 		 || (reg_config1 = i2c_smbus_read_byte_data(new_client,
692 						LM90_REG_R_CONFIG1)) < 0
693 		 || (reg_convrate = i2c_smbus_read_byte_data(new_client,
694 						LM90_REG_R_CONVRATE)) < 0)
695 			return -ENODEV;
696 
697 		if ((address == 0x4C || address == 0x4D)
698 		 && man_id == 0x01) { /* National Semiconductor */
699 			int reg_config2;
700 
701 			if ((reg_config2 = i2c_smbus_read_byte_data(new_client,
702 						LM90_REG_R_CONFIG2)) < 0)
703 				return -ENODEV;
704 
705 			if ((reg_config1 & 0x2A) == 0x00
706 			 && (reg_config2 & 0xF8) == 0x00
707 			 && reg_convrate <= 0x09) {
708 				if (address == 0x4C
709 				 && (chip_id & 0xF0) == 0x20) { /* LM90 */
710 					kind = lm90;
711 				} else
712 				if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
713 					kind = lm99;
714 					dev_info(&adapter->dev,
715 						 "Assuming LM99 chip at "
716 						 "0x%02x\n", address);
717 					dev_info(&adapter->dev,
718 						 "If it is an LM89, pass "
719 						 "force_lm86=%d,0x%02x when "
720 						 "loading the lm90 driver\n",
721 						 i2c_adapter_id(adapter),
722 						 address);
723 				} else
724 				if (address == 0x4C
725 				 && (chip_id & 0xF0) == 0x10) { /* LM86 */
726 					kind = lm86;
727 				}
728 			}
729 		} else
730 		if ((address == 0x4C || address == 0x4D)
731 		 && man_id == 0x41) { /* Analog Devices */
732 			if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
733 			 && (reg_config1 & 0x3F) == 0x00
734 			 && reg_convrate <= 0x0A) {
735 				kind = adm1032;
736 			} else
737 			if (chip_id == 0x51 /* ADT7461 */
738 			 && (reg_config1 & 0x1B) == 0x00
739 			 && reg_convrate <= 0x0A) {
740 				kind = adt7461;
741 			}
742 		} else
743 		if (man_id == 0x4D) { /* Maxim */
744 			/*
745 			 * The MAX6657, MAX6658 and MAX6659 do NOT have a
746 			 * chip_id register. Reading from that address will
747 			 * return the last read value, which in our case is
748 			 * those of the man_id register. Likewise, the config1
749 			 * register seems to lack a low nibble, so the value
750 			 * will be those of the previous read, so in our case
751 			 * those of the man_id register.
752 			 */
753 			if (chip_id == man_id
754 			 && (address == 0x4C || address == 0x4D)
755 			 && (reg_config1 & 0x1F) == (man_id & 0x0F)
756 			 && reg_convrate <= 0x09) {
757 			 	kind = max6657;
758 			} else
759 			/* The chip_id register of the MAX6680 and MAX6681
760 			 * holds the revision of the chip.
761 			 * the lowest bit of the config1 register is unused
762 			 * and should return zero when read, so should the
763 			 * second to last bit of config1 (software reset)
764 			 */
765 			if (chip_id == 0x01
766 			 && (reg_config1 & 0x03) == 0x00
767 			 && reg_convrate <= 0x07) {
768 			 	kind = max6680;
769 			} else
770 			/* The chip_id register of the MAX6646/6647/6649
771 			 * holds the revision of the chip.
772 			 * The lowest 6 bits of the config1 register are
773 			 * unused and should return zero when read.
774 			 */
775 			if (chip_id == 0x59
776 			 && (reg_config1 & 0x3f) == 0x00
777 			 && reg_convrate <= 0x07) {
778 				kind = max6646;
779 			}
780 		}
781 
782 		if (kind <= 0) { /* identification failed */
783 			dev_dbg(&adapter->dev,
784 				"Unsupported chip at 0x%02x (man_id=0x%02X, "
785 				"chip_id=0x%02X)\n", address, man_id, chip_id);
786 			return -ENODEV;
787 		}
788 	}
789 
790 	/* Fill the i2c board info */
791 	if (kind == lm90) {
792 		name = "lm90";
793 	} else if (kind == adm1032) {
794 		name = "adm1032";
795 		/* The ADM1032 supports PEC, but only if combined
796 		   transactions are not used. */
797 		if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
798 			info->flags |= I2C_CLIENT_PEC;
799 	} else if (kind == lm99) {
800 		name = "lm99";
801 	} else if (kind == lm86) {
802 		name = "lm86";
803 	} else if (kind == max6657) {
804 		name = "max6657";
805 	} else if (kind == max6680) {
806 		name = "max6680";
807 	} else if (kind == adt7461) {
808 		name = "adt7461";
809 	} else if (kind == max6646) {
810 		name = "max6646";
811 	}
812 	strlcpy(info->type, name, I2C_NAME_SIZE);
813 
814 	return 0;
815 }
816 
817 static int lm90_probe(struct i2c_client *new_client,
818 		      const struct i2c_device_id *id)
819 {
820 	struct i2c_adapter *adapter = to_i2c_adapter(new_client->dev.parent);
821 	struct lm90_data *data;
822 	int err;
823 
824 	data = kzalloc(sizeof(struct lm90_data), GFP_KERNEL);
825 	if (!data) {
826 		err = -ENOMEM;
827 		goto exit;
828 	}
829 	i2c_set_clientdata(new_client, data);
830 	mutex_init(&data->update_lock);
831 
832 	/* Set the device type */
833 	data->kind = id->driver_data;
834 	if (data->kind == adm1032) {
835 		if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
836 			new_client->flags &= ~I2C_CLIENT_PEC;
837 	}
838 
839 	/* Initialize the LM90 chip */
840 	lm90_init_client(new_client);
841 
842 	/* Register sysfs hooks */
843 	if ((err = sysfs_create_group(&new_client->dev.kobj, &lm90_group)))
844 		goto exit_free;
845 	if (new_client->flags & I2C_CLIENT_PEC) {
846 		if ((err = device_create_file(&new_client->dev,
847 					      &dev_attr_pec)))
848 			goto exit_remove_files;
849 	}
850 	if (data->kind != max6657 && data->kind != max6646) {
851 		if ((err = device_create_file(&new_client->dev,
852 				&sensor_dev_attr_temp2_offset.dev_attr)))
853 			goto exit_remove_files;
854 	}
855 
856 	data->hwmon_dev = hwmon_device_register(&new_client->dev);
857 	if (IS_ERR(data->hwmon_dev)) {
858 		err = PTR_ERR(data->hwmon_dev);
859 		goto exit_remove_files;
860 	}
861 
862 	return 0;
863 
864 exit_remove_files:
865 	sysfs_remove_group(&new_client->dev.kobj, &lm90_group);
866 	device_remove_file(&new_client->dev, &dev_attr_pec);
867 exit_free:
868 	kfree(data);
869 exit:
870 	return err;
871 }
872 
873 static void lm90_init_client(struct i2c_client *client)
874 {
875 	u8 config, config_orig;
876 	struct lm90_data *data = i2c_get_clientdata(client);
877 
878 	/*
879 	 * Start the conversions.
880 	 */
881 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
882 				  5); /* 2 Hz */
883 	if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) {
884 		dev_warn(&client->dev, "Initialization failed!\n");
885 		return;
886 	}
887 	config_orig = config;
888 
889 	/* Check Temperature Range Select */
890 	if (data->kind == adt7461) {
891 		if (config & 0x04)
892 			data->flags |= LM90_FLAG_ADT7461_EXT;
893 	}
894 
895 	/*
896 	 * Put MAX6680/MAX8881 into extended resolution (bit 0x10,
897 	 * 0.125 degree resolution) and range (0x08, extend range
898 	 * to -64 degree) mode for the remote temperature sensor.
899 	 */
900 	if (data->kind == max6680) {
901 		config |= 0x18;
902 	}
903 
904 	config &= 0xBF;	/* run */
905 	if (config != config_orig) /* Only write if changed */
906 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config);
907 }
908 
909 static int lm90_remove(struct i2c_client *client)
910 {
911 	struct lm90_data *data = i2c_get_clientdata(client);
912 
913 	hwmon_device_unregister(data->hwmon_dev);
914 	sysfs_remove_group(&client->dev.kobj, &lm90_group);
915 	device_remove_file(&client->dev, &dev_attr_pec);
916 	if (data->kind != max6657 && data->kind != max6646)
917 		device_remove_file(&client->dev,
918 				   &sensor_dev_attr_temp2_offset.dev_attr);
919 
920 	kfree(data);
921 	return 0;
922 }
923 
924 static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl, u16 *value)
925 {
926 	int err;
927 	u8 oldh, newh, l;
928 
929 	/*
930 	 * There is a trick here. We have to read two registers to have the
931 	 * sensor temperature, but we have to beware a conversion could occur
932 	 * inbetween the readings. The datasheet says we should either use
933 	 * the one-shot conversion register, which we don't want to do
934 	 * (disables hardware monitoring) or monitor the busy bit, which is
935 	 * impossible (we can't read the values and monitor that bit at the
936 	 * exact same time). So the solution used here is to read the high
937 	 * byte once, then the low byte, then the high byte again. If the new
938 	 * high byte matches the old one, then we have a valid reading. Else
939 	 * we have to read the low byte again, and now we believe we have a
940 	 * correct reading.
941 	 */
942 	if ((err = lm90_read_reg(client, regh, &oldh))
943 	 || (err = lm90_read_reg(client, regl, &l))
944 	 || (err = lm90_read_reg(client, regh, &newh)))
945 		return err;
946 	if (oldh != newh) {
947 		err = lm90_read_reg(client, regl, &l);
948 		if (err)
949 			return err;
950 	}
951 	*value = (newh << 8) | l;
952 
953 	return 0;
954 }
955 
956 static struct lm90_data *lm90_update_device(struct device *dev)
957 {
958 	struct i2c_client *client = to_i2c_client(dev);
959 	struct lm90_data *data = i2c_get_clientdata(client);
960 
961 	mutex_lock(&data->update_lock);
962 
963 	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
964 		u8 h, l;
965 
966 		dev_dbg(&client->dev, "Updating lm90 data.\n");
967 		lm90_read_reg(client, LM90_REG_R_LOCAL_LOW, &data->temp8[0]);
968 		lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH, &data->temp8[1]);
969 		lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT, &data->temp8[2]);
970 		lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[3]);
971 		lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
972 
973 		if (data->kind == max6657 || data->kind == max6646) {
974 			lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
975 				    MAX6657_REG_R_LOCAL_TEMPL,
976 				    &data->temp11[4]);
977 		} else {
978 			if (lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP,
979 					  &h) == 0)
980 				data->temp11[4] = h << 8;
981 		}
982 		lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
983 			    LM90_REG_R_REMOTE_TEMPL, &data->temp11[0]);
984 
985 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h) == 0) {
986 			data->temp11[1] = h << 8;
987 			if (data->kind != max6657 && data->kind != max6680
988 			 && data->kind != max6646
989 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL,
990 					  &l) == 0)
991 				data->temp11[1] |= l;
992 		}
993 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h) == 0) {
994 			data->temp11[2] = h << 8;
995 			if (data->kind != max6657 && data->kind != max6680
996 			 && data->kind != max6646
997 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL,
998 					  &l) == 0)
999 				data->temp11[2] |= l;
1000 		}
1001 
1002 		if (data->kind != max6657 && data->kind != max6646) {
1003 			if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
1004 					  &h) == 0
1005 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,
1006 					  &l) == 0)
1007 				data->temp11[3] = (h << 8) | l;
1008 		}
1009 		lm90_read_reg(client, LM90_REG_R_STATUS, &data->alarms);
1010 
1011 		data->last_updated = jiffies;
1012 		data->valid = 1;
1013 	}
1014 
1015 	mutex_unlock(&data->update_lock);
1016 
1017 	return data;
1018 }
1019 
1020 static int __init sensors_lm90_init(void)
1021 {
1022 	return i2c_add_driver(&lm90_driver);
1023 }
1024 
1025 static void __exit sensors_lm90_exit(void)
1026 {
1027 	i2c_del_driver(&lm90_driver);
1028 }
1029 
1030 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
1031 MODULE_DESCRIPTION("LM90/ADM1032 driver");
1032 MODULE_LICENSE("GPL");
1033 
1034 module_init(sensors_lm90_init);
1035 module_exit(sensors_lm90_exit);
1036