xref: /linux/drivers/hwmon/lm90.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
3  *          monitoring
4  * Copyright (C) 2003-2010  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. We use the device address to detect MAX6659, which will result
32  * in a detection as max6657 if it is on address 0x4c. The extra address
33  * and features of the MAX6659 are only supported if the chip is configured
34  * explicitly as max6659, or if its address is not 0x4c.
35  * These chips lack the remote temperature offset feature.
36  *
37  * This driver also supports the MAX6646, MAX6647, MAX6648, MAX6649 and
38  * MAX6692 chips made by Maxim.  These are again similar to the LM86,
39  * but they use unsigned temperature values and can report temperatures
40  * from 0 to 145 degrees.
41  *
42  * This driver also supports the MAX6680 and MAX6681, two other sensor
43  * chips made by Maxim. These are quite similar to the other Maxim
44  * chips. The MAX6680 and MAX6681 only differ in the pinout so they can
45  * be treated identically.
46  *
47  * This driver also supports the MAX6695 and MAX6696, two other sensor
48  * chips made by Maxim. These are also quite similar to other Maxim
49  * chips, but support three temperature sensors instead of two. MAX6695
50  * and MAX6696 only differ in the pinout so they can be treated identically.
51  *
52  * This driver also supports ADT7461 and ADT7461A from Analog Devices as well as
53  * NCT1008 from ON Semiconductor. The chips are supported in both compatibility
54  * and extended mode. They are mostly compatible with LM90 except for a data
55  * format difference for the temperature value registers.
56  *
57  * This driver also supports the SA56004 from Philips. This device is
58  * pin-compatible with the LM86, the ED/EDP parts are also address-compatible.
59  *
60  * Since the LM90 was the first chipset supported by this driver, most
61  * comments will refer to this chipset, but are actually general and
62  * concern all supported chipsets, unless mentioned otherwise.
63  *
64  * This program is free software; you can redistribute it and/or modify
65  * it under the terms of the GNU General Public License as published by
66  * the Free Software Foundation; either version 2 of the License, or
67  * (at your option) any later version.
68  *
69  * This program is distributed in the hope that it will be useful,
70  * but WITHOUT ANY WARRANTY; without even the implied warranty of
71  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
72  * GNU General Public License for more details.
73  *
74  * You should have received a copy of the GNU General Public License
75  * along with this program; if not, write to the Free Software
76  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
77  */
78 
79 #include <linux/module.h>
80 #include <linux/init.h>
81 #include <linux/slab.h>
82 #include <linux/jiffies.h>
83 #include <linux/i2c.h>
84 #include <linux/hwmon-sysfs.h>
85 #include <linux/hwmon.h>
86 #include <linux/err.h>
87 #include <linux/mutex.h>
88 #include <linux/sysfs.h>
89 
90 /*
91  * Addresses to scan
92  * Address is fully defined internally and cannot be changed except for
93  * MAX6659, MAX6680 and MAX6681.
94  * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, ADT7461A, MAX6649,
95  * MAX6657, MAX6658, NCT1008 and W83L771 have address 0x4c.
96  * ADM1032-2, ADT7461-2, ADT7461A-2, LM89-1, LM99-1, MAX6646, and NCT1008D
97  * have address 0x4d.
98  * MAX6647 has address 0x4e.
99  * MAX6659 can have address 0x4c, 0x4d or 0x4e.
100  * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
101  * 0x4c, 0x4d or 0x4e.
102  * SA56004 can have address 0x48 through 0x4F.
103  */
104 
105 static const unsigned short normal_i2c[] = {
106 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x48, 0x49, 0x4a, 0x4b, 0x4c,
107 	0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
108 
109 enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
110 	max6646, w83l771, max6696, sa56004 };
111 
112 /*
113  * The LM90 registers
114  */
115 
116 #define LM90_REG_R_MAN_ID		0xFE
117 #define LM90_REG_R_CHIP_ID		0xFF
118 #define LM90_REG_R_CONFIG1		0x03
119 #define LM90_REG_W_CONFIG1		0x09
120 #define LM90_REG_R_CONFIG2		0xBF
121 #define LM90_REG_W_CONFIG2		0xBF
122 #define LM90_REG_R_CONVRATE		0x04
123 #define LM90_REG_W_CONVRATE		0x0A
124 #define LM90_REG_R_STATUS		0x02
125 #define LM90_REG_R_LOCAL_TEMP		0x00
126 #define LM90_REG_R_LOCAL_HIGH		0x05
127 #define LM90_REG_W_LOCAL_HIGH		0x0B
128 #define LM90_REG_R_LOCAL_LOW		0x06
129 #define LM90_REG_W_LOCAL_LOW		0x0C
130 #define LM90_REG_R_LOCAL_CRIT		0x20
131 #define LM90_REG_W_LOCAL_CRIT		0x20
132 #define LM90_REG_R_REMOTE_TEMPH		0x01
133 #define LM90_REG_R_REMOTE_TEMPL		0x10
134 #define LM90_REG_R_REMOTE_OFFSH		0x11
135 #define LM90_REG_W_REMOTE_OFFSH		0x11
136 #define LM90_REG_R_REMOTE_OFFSL		0x12
137 #define LM90_REG_W_REMOTE_OFFSL		0x12
138 #define LM90_REG_R_REMOTE_HIGHH		0x07
139 #define LM90_REG_W_REMOTE_HIGHH		0x0D
140 #define LM90_REG_R_REMOTE_HIGHL		0x13
141 #define LM90_REG_W_REMOTE_HIGHL		0x13
142 #define LM90_REG_R_REMOTE_LOWH		0x08
143 #define LM90_REG_W_REMOTE_LOWH		0x0E
144 #define LM90_REG_R_REMOTE_LOWL		0x14
145 #define LM90_REG_W_REMOTE_LOWL		0x14
146 #define LM90_REG_R_REMOTE_CRIT		0x19
147 #define LM90_REG_W_REMOTE_CRIT		0x19
148 #define LM90_REG_R_TCRIT_HYST		0x21
149 #define LM90_REG_W_TCRIT_HYST		0x21
150 
151 /* MAX6646/6647/6649/6657/6658/6659/6695/6696 registers */
152 
153 #define MAX6657_REG_R_LOCAL_TEMPL	0x11
154 #define MAX6696_REG_R_STATUS2		0x12
155 #define MAX6659_REG_R_REMOTE_EMERG	0x16
156 #define MAX6659_REG_W_REMOTE_EMERG	0x16
157 #define MAX6659_REG_R_LOCAL_EMERG	0x17
158 #define MAX6659_REG_W_LOCAL_EMERG	0x17
159 
160 /*  SA56004 registers */
161 
162 #define SA56004_REG_R_LOCAL_TEMPL 0x22
163 
164 #define LM90_DEF_CONVRATE_RVAL	6	/* Def conversion rate register value */
165 #define LM90_MAX_CONVRATE_MS	16000	/* Maximum conversion rate in ms */
166 
167 /*
168  * Device flags
169  */
170 #define LM90_FLAG_ADT7461_EXT	(1 << 0) /* ADT7461 extended mode	*/
171 /* Device features */
172 #define LM90_HAVE_OFFSET	(1 << 1) /* temperature offset register	*/
173 #define LM90_HAVE_REM_LIMIT_EXT	(1 << 3) /* extended remote limit	*/
174 #define LM90_HAVE_EMERGENCY	(1 << 4) /* 3rd upper (emergency) limit	*/
175 #define LM90_HAVE_EMERGENCY_ALARM (1 << 5)/* emergency alarm		*/
176 #define LM90_HAVE_TEMP3		(1 << 6) /* 3rd temperature sensor	*/
177 #define LM90_HAVE_BROKEN_ALERT	(1 << 7) /* Broken alert		*/
178 
179 /*
180  * Driver data (common to all clients)
181  */
182 
183 static const struct i2c_device_id lm90_id[] = {
184 	{ "adm1032", adm1032 },
185 	{ "adt7461", adt7461 },
186 	{ "adt7461a", adt7461 },
187 	{ "lm90", lm90 },
188 	{ "lm86", lm86 },
189 	{ "lm89", lm86 },
190 	{ "lm99", lm99 },
191 	{ "max6646", max6646 },
192 	{ "max6647", max6646 },
193 	{ "max6649", max6646 },
194 	{ "max6657", max6657 },
195 	{ "max6658", max6657 },
196 	{ "max6659", max6659 },
197 	{ "max6680", max6680 },
198 	{ "max6681", max6680 },
199 	{ "max6695", max6696 },
200 	{ "max6696", max6696 },
201 	{ "nct1008", adt7461 },
202 	{ "w83l771", w83l771 },
203 	{ "sa56004", sa56004 },
204 	{ }
205 };
206 MODULE_DEVICE_TABLE(i2c, lm90_id);
207 
208 /*
209  * chip type specific parameters
210  */
211 struct lm90_params {
212 	u32 flags;		/* Capabilities */
213 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
214 				/* Upper 8 bits for max6695/96 */
215 	u8 max_convrate;	/* Maximum conversion rate register value */
216 	u8 reg_local_ext;	/* Extended local temp register (optional) */
217 };
218 
219 static const struct lm90_params lm90_params[] = {
220 	[adm1032] = {
221 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
222 		  | LM90_HAVE_BROKEN_ALERT,
223 		.alert_alarms = 0x7c,
224 		.max_convrate = 10,
225 	},
226 	[adt7461] = {
227 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
228 		  | LM90_HAVE_BROKEN_ALERT,
229 		.alert_alarms = 0x7c,
230 		.max_convrate = 10,
231 	},
232 	[lm86] = {
233 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
234 		.alert_alarms = 0x7b,
235 		.max_convrate = 9,
236 	},
237 	[lm90] = {
238 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
239 		.alert_alarms = 0x7b,
240 		.max_convrate = 9,
241 	},
242 	[lm99] = {
243 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
244 		.alert_alarms = 0x7b,
245 		.max_convrate = 9,
246 	},
247 	[max6646] = {
248 		.alert_alarms = 0x7c,
249 		.max_convrate = 6,
250 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
251 	},
252 	[max6657] = {
253 		.alert_alarms = 0x7c,
254 		.max_convrate = 8,
255 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
256 	},
257 	[max6659] = {
258 		.flags = LM90_HAVE_EMERGENCY,
259 		.alert_alarms = 0x7c,
260 		.max_convrate = 8,
261 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
262 	},
263 	[max6680] = {
264 		.flags = LM90_HAVE_OFFSET,
265 		.alert_alarms = 0x7c,
266 		.max_convrate = 7,
267 	},
268 	[max6696] = {
269 		.flags = LM90_HAVE_EMERGENCY
270 		  | LM90_HAVE_EMERGENCY_ALARM | LM90_HAVE_TEMP3,
271 		.alert_alarms = 0x187c,
272 		.max_convrate = 6,
273 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
274 	},
275 	[w83l771] = {
276 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
277 		.alert_alarms = 0x7c,
278 		.max_convrate = 8,
279 	},
280 	[sa56004] = {
281 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
282 		.alert_alarms = 0x7b,
283 		.max_convrate = 9,
284 		.reg_local_ext = SA56004_REG_R_LOCAL_TEMPL,
285 	},
286 };
287 
288 /*
289  * Client data (each client gets its own)
290  */
291 
292 struct lm90_data {
293 	struct device *hwmon_dev;
294 	struct mutex update_lock;
295 	char valid; /* zero until following fields are valid */
296 	unsigned long last_updated; /* in jiffies */
297 	int kind;
298 	u32 flags;
299 
300 	int update_interval;	/* in milliseconds */
301 
302 	u8 config_orig;		/* Original configuration register value */
303 	u8 convrate_orig;	/* Original conversion rate register value */
304 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
305 				/* Upper 8 bits for max6695/96 */
306 	u8 max_convrate;	/* Maximum conversion rate */
307 	u8 reg_local_ext;	/* local extension register offset */
308 
309 	/* registers values */
310 	s8 temp8[8];	/* 0: local low limit
311 			   1: local high limit
312 			   2: local critical limit
313 			   3: remote critical limit
314 			   4: local emergency limit (max6659 and max6695/96)
315 			   5: remote emergency limit (max6659 and max6695/96)
316 			   6: remote 2 critical limit (max6695/96 only)
317 			   7: remote 2 emergency limit (max6695/96 only) */
318 	s16 temp11[8];	/* 0: remote input
319 			   1: remote low limit
320 			   2: remote high limit
321 			   3: remote offset (except max6646, max6657/58/59,
322 					     and max6695/96)
323 			   4: local input
324 			   5: remote 2 input (max6695/96 only)
325 			   6: remote 2 low limit (max6695/96 only)
326 			   7: remote 2 high limit (ma6695/96 only) */
327 	u8 temp_hyst;
328 	u16 alarms; /* bitvector (upper 8 bits for max6695/96) */
329 };
330 
331 /*
332  * Support functions
333  */
334 
335 /*
336  * The ADM1032 supports PEC but not on write byte transactions, so we need
337  * to explicitly ask for a transaction without PEC.
338  */
339 static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value)
340 {
341 	return i2c_smbus_xfer(client->adapter, client->addr,
342 			      client->flags & ~I2C_CLIENT_PEC,
343 			      I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
344 }
345 
346 /*
347  * It is assumed that client->update_lock is held (unless we are in
348  * detection or initialization steps). This matters when PEC is enabled,
349  * because we don't want the address pointer to change between the write
350  * byte and the read byte transactions.
351  */
352 static int lm90_read_reg(struct i2c_client *client, u8 reg, u8 *value)
353 {
354 	int err;
355 
356 	if (client->flags & I2C_CLIENT_PEC) {
357 		err = adm1032_write_byte(client, reg);
358 		if (err >= 0)
359 			err = i2c_smbus_read_byte(client);
360 	} else
361 		err = i2c_smbus_read_byte_data(client, reg);
362 
363 	if (err < 0) {
364 		dev_warn(&client->dev, "Register %#02x read failed (%d)\n",
365 			 reg, err);
366 		return err;
367 	}
368 	*value = err;
369 
370 	return 0;
371 }
372 
373 static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl, u16 *value)
374 {
375 	int err;
376 	u8 oldh, newh, l;
377 
378 	/*
379 	 * There is a trick here. We have to read two registers to have the
380 	 * sensor temperature, but we have to beware a conversion could occur
381 	 * between the readings. The datasheet says we should either use
382 	 * the one-shot conversion register, which we don't want to do
383 	 * (disables hardware monitoring) or monitor the busy bit, which is
384 	 * impossible (we can't read the values and monitor that bit at the
385 	 * exact same time). So the solution used here is to read the high
386 	 * byte once, then the low byte, then the high byte again. If the new
387 	 * high byte matches the old one, then we have a valid reading. Else
388 	 * we have to read the low byte again, and now we believe we have a
389 	 * correct reading.
390 	 */
391 	if ((err = lm90_read_reg(client, regh, &oldh))
392 	 || (err = lm90_read_reg(client, regl, &l))
393 	 || (err = lm90_read_reg(client, regh, &newh)))
394 		return err;
395 	if (oldh != newh) {
396 		err = lm90_read_reg(client, regl, &l);
397 		if (err)
398 			return err;
399 	}
400 	*value = (newh << 8) | l;
401 
402 	return 0;
403 }
404 
405 /*
406  * client->update_lock must be held when calling this function (unless we are
407  * in detection or initialization steps), and while a remote channel other
408  * than channel 0 is selected. Also, calling code must make sure to re-select
409  * external channel 0 before releasing the lock. This is necessary because
410  * various registers have different meanings as a result of selecting a
411  * non-default remote channel.
412  */
413 static inline void lm90_select_remote_channel(struct i2c_client *client,
414 					      struct lm90_data *data,
415 					      int channel)
416 {
417 	u8 config;
418 
419 	if (data->kind == max6696) {
420 		lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
421 		config &= ~0x08;
422 		if (channel)
423 			config |= 0x08;
424 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
425 					  config);
426 	}
427 }
428 
429 /*
430  * Set conversion rate.
431  * client->update_lock must be held when calling this function (unless we are
432  * in detection or initialization steps).
433  */
434 static void lm90_set_convrate(struct i2c_client *client, struct lm90_data *data,
435 			      unsigned int interval)
436 {
437 	int i;
438 	unsigned int update_interval;
439 
440 	/* Shift calculations to avoid rounding errors */
441 	interval <<= 6;
442 
443 	/* find the nearest update rate */
444 	for (i = 0, update_interval = LM90_MAX_CONVRATE_MS << 6;
445 	     i < data->max_convrate; i++, update_interval >>= 1)
446 		if (interval >= update_interval * 3 / 4)
447 			break;
448 
449 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, i);
450 	data->update_interval = DIV_ROUND_CLOSEST(update_interval, 64);
451 }
452 
453 static struct lm90_data *lm90_update_device(struct device *dev)
454 {
455 	struct i2c_client *client = to_i2c_client(dev);
456 	struct lm90_data *data = i2c_get_clientdata(client);
457 	unsigned long next_update;
458 
459 	mutex_lock(&data->update_lock);
460 
461 	next_update = data->last_updated
462 	  + msecs_to_jiffies(data->update_interval) + 1;
463 	if (time_after(jiffies, next_update) || !data->valid) {
464 		u8 h, l;
465 		u8 alarms;
466 
467 		dev_dbg(&client->dev, "Updating lm90 data.\n");
468 		lm90_read_reg(client, LM90_REG_R_LOCAL_LOW, &data->temp8[0]);
469 		lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH, &data->temp8[1]);
470 		lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT, &data->temp8[2]);
471 		lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[3]);
472 		lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
473 
474 		if (data->reg_local_ext) {
475 			lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
476 				    data->reg_local_ext,
477 				    &data->temp11[4]);
478 		} else {
479 			if (lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP,
480 					  &h) == 0)
481 				data->temp11[4] = h << 8;
482 		}
483 		lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
484 			    LM90_REG_R_REMOTE_TEMPL, &data->temp11[0]);
485 
486 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h) == 0) {
487 			data->temp11[1] = h << 8;
488 			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
489 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL,
490 					  &l) == 0)
491 				data->temp11[1] |= l;
492 		}
493 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h) == 0) {
494 			data->temp11[2] = h << 8;
495 			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
496 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL,
497 					  &l) == 0)
498 				data->temp11[2] |= l;
499 		}
500 
501 		if (data->flags & LM90_HAVE_OFFSET) {
502 			if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
503 					  &h) == 0
504 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,
505 					  &l) == 0)
506 				data->temp11[3] = (h << 8) | l;
507 		}
508 		if (data->flags & LM90_HAVE_EMERGENCY) {
509 			lm90_read_reg(client, MAX6659_REG_R_LOCAL_EMERG,
510 				      &data->temp8[4]);
511 			lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
512 				      &data->temp8[5]);
513 		}
514 		lm90_read_reg(client, LM90_REG_R_STATUS, &alarms);
515 		data->alarms = alarms;	/* save as 16 bit value */
516 
517 		if (data->kind == max6696) {
518 			lm90_select_remote_channel(client, data, 1);
519 			lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT,
520 				      &data->temp8[6]);
521 			lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
522 				      &data->temp8[7]);
523 			lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
524 				    LM90_REG_R_REMOTE_TEMPL, &data->temp11[5]);
525 			if (!lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h))
526 				data->temp11[6] = h << 8;
527 			if (!lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h))
528 				data->temp11[7] = h << 8;
529 			lm90_select_remote_channel(client, data, 0);
530 
531 			if (!lm90_read_reg(client, MAX6696_REG_R_STATUS2,
532 					   &alarms))
533 				data->alarms |= alarms << 8;
534 		}
535 
536 		/* Re-enable ALERT# output if it was originally enabled and
537 		 * relevant alarms are all clear */
538 		if ((data->config_orig & 0x80) == 0
539 		 && (data->alarms & data->alert_alarms) == 0) {
540 			u8 config;
541 
542 			lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
543 			if (config & 0x80) {
544 				dev_dbg(&client->dev, "Re-enabling ALERT#\n");
545 				i2c_smbus_write_byte_data(client,
546 							  LM90_REG_W_CONFIG1,
547 							  config & ~0x80);
548 			}
549 		}
550 
551 		data->last_updated = jiffies;
552 		data->valid = 1;
553 	}
554 
555 	mutex_unlock(&data->update_lock);
556 
557 	return data;
558 }
559 
560 /*
561  * Conversions
562  * For local temperatures and limits, critical limits and the hysteresis
563  * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
564  * For remote temperatures and limits, it uses signed 11-bit values with
565  * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.  Some
566  * Maxim chips use unsigned values.
567  */
568 
569 static inline int temp_from_s8(s8 val)
570 {
571 	return val * 1000;
572 }
573 
574 static inline int temp_from_u8(u8 val)
575 {
576 	return val * 1000;
577 }
578 
579 static inline int temp_from_s16(s16 val)
580 {
581 	return val / 32 * 125;
582 }
583 
584 static inline int temp_from_u16(u16 val)
585 {
586 	return val / 32 * 125;
587 }
588 
589 static s8 temp_to_s8(long val)
590 {
591 	if (val <= -128000)
592 		return -128;
593 	if (val >= 127000)
594 		return 127;
595 	if (val < 0)
596 		return (val - 500) / 1000;
597 	return (val + 500) / 1000;
598 }
599 
600 static u8 temp_to_u8(long val)
601 {
602 	if (val <= 0)
603 		return 0;
604 	if (val >= 255000)
605 		return 255;
606 	return (val + 500) / 1000;
607 }
608 
609 static s16 temp_to_s16(long val)
610 {
611 	if (val <= -128000)
612 		return 0x8000;
613 	if (val >= 127875)
614 		return 0x7FE0;
615 	if (val < 0)
616 		return (val - 62) / 125 * 32;
617 	return (val + 62) / 125 * 32;
618 }
619 
620 static u8 hyst_to_reg(long val)
621 {
622 	if (val <= 0)
623 		return 0;
624 	if (val >= 30500)
625 		return 31;
626 	return (val + 500) / 1000;
627 }
628 
629 /*
630  * ADT7461 in compatibility mode is almost identical to LM90 except that
631  * attempts to write values that are outside the range 0 < temp < 127 are
632  * treated as the boundary value.
633  *
634  * ADT7461 in "extended mode" operation uses unsigned integers offset by
635  * 64 (e.g., 0 -> -64 degC).  The range is restricted to -64..191 degC.
636  */
637 static inline int temp_from_u8_adt7461(struct lm90_data *data, u8 val)
638 {
639 	if (data->flags & LM90_FLAG_ADT7461_EXT)
640 		return (val - 64) * 1000;
641 	else
642 		return temp_from_s8(val);
643 }
644 
645 static inline int temp_from_u16_adt7461(struct lm90_data *data, u16 val)
646 {
647 	if (data->flags & LM90_FLAG_ADT7461_EXT)
648 		return (val - 0x4000) / 64 * 250;
649 	else
650 		return temp_from_s16(val);
651 }
652 
653 static u8 temp_to_u8_adt7461(struct lm90_data *data, long val)
654 {
655 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
656 		if (val <= -64000)
657 			return 0;
658 		if (val >= 191000)
659 			return 0xFF;
660 		return (val + 500 + 64000) / 1000;
661 	} else {
662 		if (val <= 0)
663 			return 0;
664 		if (val >= 127000)
665 			return 127;
666 		return (val + 500) / 1000;
667 	}
668 }
669 
670 static u16 temp_to_u16_adt7461(struct lm90_data *data, long val)
671 {
672 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
673 		if (val <= -64000)
674 			return 0;
675 		if (val >= 191750)
676 			return 0xFFC0;
677 		return (val + 64000 + 125) / 250 * 64;
678 	} else {
679 		if (val <= 0)
680 			return 0;
681 		if (val >= 127750)
682 			return 0x7FC0;
683 		return (val + 125) / 250 * 64;
684 	}
685 }
686 
687 /*
688  * Sysfs stuff
689  */
690 
691 static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
692 			  char *buf)
693 {
694 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
695 	struct lm90_data *data = lm90_update_device(dev);
696 	int temp;
697 
698 	if (data->kind == adt7461)
699 		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
700 	else if (data->kind == max6646)
701 		temp = temp_from_u8(data->temp8[attr->index]);
702 	else
703 		temp = temp_from_s8(data->temp8[attr->index]);
704 
705 	/* +16 degrees offset for temp2 for the LM99 */
706 	if (data->kind == lm99 && attr->index == 3)
707 		temp += 16000;
708 
709 	return sprintf(buf, "%d\n", temp);
710 }
711 
712 static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
713 			 const char *buf, size_t count)
714 {
715 	static const u8 reg[8] = {
716 		LM90_REG_W_LOCAL_LOW,
717 		LM90_REG_W_LOCAL_HIGH,
718 		LM90_REG_W_LOCAL_CRIT,
719 		LM90_REG_W_REMOTE_CRIT,
720 		MAX6659_REG_W_LOCAL_EMERG,
721 		MAX6659_REG_W_REMOTE_EMERG,
722 		LM90_REG_W_REMOTE_CRIT,
723 		MAX6659_REG_W_REMOTE_EMERG,
724 	};
725 
726 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
727 	struct i2c_client *client = to_i2c_client(dev);
728 	struct lm90_data *data = i2c_get_clientdata(client);
729 	int nr = attr->index;
730 	long val;
731 	int err;
732 
733 	err = strict_strtol(buf, 10, &val);
734 	if (err < 0)
735 		return err;
736 
737 	/* +16 degrees offset for temp2 for the LM99 */
738 	if (data->kind == lm99 && attr->index == 3)
739 		val -= 16000;
740 
741 	mutex_lock(&data->update_lock);
742 	if (data->kind == adt7461)
743 		data->temp8[nr] = temp_to_u8_adt7461(data, val);
744 	else if (data->kind == max6646)
745 		data->temp8[nr] = temp_to_u8(val);
746 	else
747 		data->temp8[nr] = temp_to_s8(val);
748 
749 	lm90_select_remote_channel(client, data, nr >= 6);
750 	i2c_smbus_write_byte_data(client, reg[nr], data->temp8[nr]);
751 	lm90_select_remote_channel(client, data, 0);
752 
753 	mutex_unlock(&data->update_lock);
754 	return count;
755 }
756 
757 static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
758 			   char *buf)
759 {
760 	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
761 	struct lm90_data *data = lm90_update_device(dev);
762 	int temp;
763 
764 	if (data->kind == adt7461)
765 		temp = temp_from_u16_adt7461(data, data->temp11[attr->index]);
766 	else if (data->kind == max6646)
767 		temp = temp_from_u16(data->temp11[attr->index]);
768 	else
769 		temp = temp_from_s16(data->temp11[attr->index]);
770 
771 	/* +16 degrees offset for temp2 for the LM99 */
772 	if (data->kind == lm99 &&  attr->index <= 2)
773 		temp += 16000;
774 
775 	return sprintf(buf, "%d\n", temp);
776 }
777 
778 static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
779 			  const char *buf, size_t count)
780 {
781 	struct {
782 		u8 high;
783 		u8 low;
784 		int channel;
785 	} reg[5] = {
786 		{ LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL, 0 },
787 		{ LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 0 },
788 		{ LM90_REG_W_REMOTE_OFFSH, LM90_REG_W_REMOTE_OFFSL, 0 },
789 		{ LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL, 1 },
790 		{ LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 1 }
791 	};
792 
793 	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
794 	struct i2c_client *client = to_i2c_client(dev);
795 	struct lm90_data *data = i2c_get_clientdata(client);
796 	int nr = attr->nr;
797 	int index = attr->index;
798 	long val;
799 	int err;
800 
801 	err = strict_strtol(buf, 10, &val);
802 	if (err < 0)
803 		return err;
804 
805 	/* +16 degrees offset for temp2 for the LM99 */
806 	if (data->kind == lm99 && index <= 2)
807 		val -= 16000;
808 
809 	mutex_lock(&data->update_lock);
810 	if (data->kind == adt7461)
811 		data->temp11[index] = temp_to_u16_adt7461(data, val);
812 	else if (data->kind == max6646)
813 		data->temp11[index] = temp_to_u8(val) << 8;
814 	else if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
815 		data->temp11[index] = temp_to_s16(val);
816 	else
817 		data->temp11[index] = temp_to_s8(val) << 8;
818 
819 	lm90_select_remote_channel(client, data, reg[nr].channel);
820 	i2c_smbus_write_byte_data(client, reg[nr].high,
821 				  data->temp11[index] >> 8);
822 	if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
823 		i2c_smbus_write_byte_data(client, reg[nr].low,
824 					  data->temp11[index] & 0xff);
825 	lm90_select_remote_channel(client, data, 0);
826 
827 	mutex_unlock(&data->update_lock);
828 	return count;
829 }
830 
831 static ssize_t show_temphyst(struct device *dev,
832 			     struct device_attribute *devattr,
833 			     char *buf)
834 {
835 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
836 	struct lm90_data *data = lm90_update_device(dev);
837 	int temp;
838 
839 	if (data->kind == adt7461)
840 		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
841 	else if (data->kind == max6646)
842 		temp = temp_from_u8(data->temp8[attr->index]);
843 	else
844 		temp = temp_from_s8(data->temp8[attr->index]);
845 
846 	/* +16 degrees offset for temp2 for the LM99 */
847 	if (data->kind == lm99 && attr->index == 3)
848 		temp += 16000;
849 
850 	return sprintf(buf, "%d\n", temp - temp_from_s8(data->temp_hyst));
851 }
852 
853 static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
854 			    const char *buf, size_t count)
855 {
856 	struct i2c_client *client = to_i2c_client(dev);
857 	struct lm90_data *data = i2c_get_clientdata(client);
858 	long val;
859 	int err;
860 	int temp;
861 
862 	err = strict_strtol(buf, 10, &val);
863 	if (err < 0)
864 		return err;
865 
866 	mutex_lock(&data->update_lock);
867 	if (data->kind == adt7461)
868 		temp = temp_from_u8_adt7461(data, data->temp8[2]);
869 	else if (data->kind == max6646)
870 		temp = temp_from_u8(data->temp8[2]);
871 	else
872 		temp = temp_from_s8(data->temp8[2]);
873 
874 	data->temp_hyst = hyst_to_reg(temp - val);
875 	i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
876 				  data->temp_hyst);
877 	mutex_unlock(&data->update_lock);
878 	return count;
879 }
880 
881 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
882 			   char *buf)
883 {
884 	struct lm90_data *data = lm90_update_device(dev);
885 	return sprintf(buf, "%d\n", data->alarms);
886 }
887 
888 static ssize_t show_alarm(struct device *dev, struct device_attribute
889 			  *devattr, char *buf)
890 {
891 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
892 	struct lm90_data *data = lm90_update_device(dev);
893 	int bitnr = attr->index;
894 
895 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
896 }
897 
898 static ssize_t show_update_interval(struct device *dev,
899 				    struct device_attribute *attr, char *buf)
900 {
901 	struct lm90_data *data = dev_get_drvdata(dev);
902 
903 	return sprintf(buf, "%u\n", data->update_interval);
904 }
905 
906 static ssize_t set_update_interval(struct device *dev,
907 				   struct device_attribute *attr,
908 				   const char *buf, size_t count)
909 {
910 	struct i2c_client *client = to_i2c_client(dev);
911 	struct lm90_data *data = i2c_get_clientdata(client);
912 	unsigned long val;
913 	int err;
914 
915 	err = strict_strtoul(buf, 10, &val);
916 	if (err)
917 		return err;
918 
919 	mutex_lock(&data->update_lock);
920 	lm90_set_convrate(client, data, val);
921 	mutex_unlock(&data->update_lock);
922 
923 	return count;
924 }
925 
926 static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp11, NULL, 0, 4);
927 static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp11, NULL, 0, 0);
928 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
929 	set_temp8, 0);
930 static SENSOR_DEVICE_ATTR_2(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
931 	set_temp11, 0, 1);
932 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
933 	set_temp8, 1);
934 static SENSOR_DEVICE_ATTR_2(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
935 	set_temp11, 1, 2);
936 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
937 	set_temp8, 2);
938 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
939 	set_temp8, 3);
940 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
941 	set_temphyst, 2);
942 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 3);
943 static SENSOR_DEVICE_ATTR_2(temp2_offset, S_IWUSR | S_IRUGO, show_temp11,
944 	set_temp11, 2, 3);
945 
946 /* Individual alarm files */
947 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
948 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
949 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
950 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
951 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
952 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 5);
953 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
954 /* Raw alarm file for compatibility */
955 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
956 
957 static DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR, show_update_interval,
958 		   set_update_interval);
959 
960 static struct attribute *lm90_attributes[] = {
961 	&sensor_dev_attr_temp1_input.dev_attr.attr,
962 	&sensor_dev_attr_temp2_input.dev_attr.attr,
963 	&sensor_dev_attr_temp1_min.dev_attr.attr,
964 	&sensor_dev_attr_temp2_min.dev_attr.attr,
965 	&sensor_dev_attr_temp1_max.dev_attr.attr,
966 	&sensor_dev_attr_temp2_max.dev_attr.attr,
967 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
968 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
969 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
970 	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
971 
972 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
973 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
974 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
975 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
976 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
977 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
978 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
979 	&dev_attr_alarms.attr,
980 	&dev_attr_update_interval.attr,
981 	NULL
982 };
983 
984 static const struct attribute_group lm90_group = {
985 	.attrs = lm90_attributes,
986 };
987 
988 /*
989  * Additional attributes for devices with emergency sensors
990  */
991 static SENSOR_DEVICE_ATTR(temp1_emergency, S_IWUSR | S_IRUGO, show_temp8,
992 	set_temp8, 4);
993 static SENSOR_DEVICE_ATTR(temp2_emergency, S_IWUSR | S_IRUGO, show_temp8,
994 	set_temp8, 5);
995 static SENSOR_DEVICE_ATTR(temp1_emergency_hyst, S_IRUGO, show_temphyst,
996 			  NULL, 4);
997 static SENSOR_DEVICE_ATTR(temp2_emergency_hyst, S_IRUGO, show_temphyst,
998 			  NULL, 5);
999 
1000 static struct attribute *lm90_emergency_attributes[] = {
1001 	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
1002 	&sensor_dev_attr_temp2_emergency.dev_attr.attr,
1003 	&sensor_dev_attr_temp1_emergency_hyst.dev_attr.attr,
1004 	&sensor_dev_attr_temp2_emergency_hyst.dev_attr.attr,
1005 	NULL
1006 };
1007 
1008 static const struct attribute_group lm90_emergency_group = {
1009 	.attrs = lm90_emergency_attributes,
1010 };
1011 
1012 static SENSOR_DEVICE_ATTR(temp1_emergency_alarm, S_IRUGO, show_alarm, NULL, 15);
1013 static SENSOR_DEVICE_ATTR(temp2_emergency_alarm, S_IRUGO, show_alarm, NULL, 13);
1014 
1015 static struct attribute *lm90_emergency_alarm_attributes[] = {
1016 	&sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
1017 	&sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
1018 	NULL
1019 };
1020 
1021 static const struct attribute_group lm90_emergency_alarm_group = {
1022 	.attrs = lm90_emergency_alarm_attributes,
1023 };
1024 
1025 /*
1026  * Additional attributes for devices with 3 temperature sensors
1027  */
1028 static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp11, NULL, 0, 5);
1029 static SENSOR_DEVICE_ATTR_2(temp3_min, S_IWUSR | S_IRUGO, show_temp11,
1030 	set_temp11, 3, 6);
1031 static SENSOR_DEVICE_ATTR_2(temp3_max, S_IWUSR | S_IRUGO, show_temp11,
1032 	set_temp11, 4, 7);
1033 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp8,
1034 	set_temp8, 6);
1035 static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO, show_temphyst, NULL, 6);
1036 static SENSOR_DEVICE_ATTR(temp3_emergency, S_IWUSR | S_IRUGO, show_temp8,
1037 	set_temp8, 7);
1038 static SENSOR_DEVICE_ATTR(temp3_emergency_hyst, S_IRUGO, show_temphyst,
1039 			  NULL, 7);
1040 
1041 static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
1042 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 10);
1043 static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_alarm, NULL, 11);
1044 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 12);
1045 static SENSOR_DEVICE_ATTR(temp3_emergency_alarm, S_IRUGO, show_alarm, NULL, 14);
1046 
1047 static struct attribute *lm90_temp3_attributes[] = {
1048 	&sensor_dev_attr_temp3_input.dev_attr.attr,
1049 	&sensor_dev_attr_temp3_min.dev_attr.attr,
1050 	&sensor_dev_attr_temp3_max.dev_attr.attr,
1051 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
1052 	&sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
1053 	&sensor_dev_attr_temp3_emergency.dev_attr.attr,
1054 	&sensor_dev_attr_temp3_emergency_hyst.dev_attr.attr,
1055 
1056 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
1057 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
1058 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
1059 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
1060 	&sensor_dev_attr_temp3_emergency_alarm.dev_attr.attr,
1061 	NULL
1062 };
1063 
1064 static const struct attribute_group lm90_temp3_group = {
1065 	.attrs = lm90_temp3_attributes,
1066 };
1067 
1068 /* pec used for ADM1032 only */
1069 static ssize_t show_pec(struct device *dev, struct device_attribute *dummy,
1070 			char *buf)
1071 {
1072 	struct i2c_client *client = to_i2c_client(dev);
1073 	return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
1074 }
1075 
1076 static ssize_t set_pec(struct device *dev, struct device_attribute *dummy,
1077 		       const char *buf, size_t count)
1078 {
1079 	struct i2c_client *client = to_i2c_client(dev);
1080 	long val;
1081 	int err;
1082 
1083 	err = strict_strtol(buf, 10, &val);
1084 	if (err < 0)
1085 		return err;
1086 
1087 	switch (val) {
1088 	case 0:
1089 		client->flags &= ~I2C_CLIENT_PEC;
1090 		break;
1091 	case 1:
1092 		client->flags |= I2C_CLIENT_PEC;
1093 		break;
1094 	default:
1095 		return -EINVAL;
1096 	}
1097 
1098 	return count;
1099 }
1100 
1101 static DEVICE_ATTR(pec, S_IWUSR | S_IRUGO, show_pec, set_pec);
1102 
1103 /*
1104  * Real code
1105  */
1106 
1107 /* Return 0 if detection is successful, -ENODEV otherwise */
1108 static int lm90_detect(struct i2c_client *new_client,
1109 		       struct i2c_board_info *info)
1110 {
1111 	struct i2c_adapter *adapter = new_client->adapter;
1112 	int address = new_client->addr;
1113 	const char *name = NULL;
1114 	int man_id, chip_id, reg_config1, reg_config2, reg_convrate;
1115 
1116 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
1117 		return -ENODEV;
1118 
1119 	/* detection and identification */
1120 	if ((man_id = i2c_smbus_read_byte_data(new_client,
1121 						LM90_REG_R_MAN_ID)) < 0
1122 	 || (chip_id = i2c_smbus_read_byte_data(new_client,
1123 						LM90_REG_R_CHIP_ID)) < 0
1124 	 || (reg_config1 = i2c_smbus_read_byte_data(new_client,
1125 						LM90_REG_R_CONFIG1)) < 0
1126 	 || (reg_convrate = i2c_smbus_read_byte_data(new_client,
1127 						LM90_REG_R_CONVRATE)) < 0)
1128 		return -ENODEV;
1129 
1130 	if (man_id == 0x01 || man_id == 0x5C || man_id == 0x41) {
1131 		reg_config2 = i2c_smbus_read_byte_data(new_client,
1132 						LM90_REG_R_CONFIG2);
1133 		if (reg_config2 < 0)
1134 			return -ENODEV;
1135 	} else
1136 		reg_config2 = 0;	/* Make compiler happy */
1137 
1138 	if ((address == 0x4C || address == 0x4D)
1139 	 && man_id == 0x01) { /* National Semiconductor */
1140 		if ((reg_config1 & 0x2A) == 0x00
1141 		 && (reg_config2 & 0xF8) == 0x00
1142 		 && reg_convrate <= 0x09) {
1143 			if (address == 0x4C
1144 			 && (chip_id & 0xF0) == 0x20) { /* LM90 */
1145 				name = "lm90";
1146 			} else
1147 			if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
1148 				name = "lm99";
1149 				dev_info(&adapter->dev,
1150 					 "Assuming LM99 chip at 0x%02x\n",
1151 					 address);
1152 				dev_info(&adapter->dev,
1153 					 "If it is an LM89, instantiate it "
1154 					 "with the new_device sysfs "
1155 					 "interface\n");
1156 			} else
1157 			if (address == 0x4C
1158 			 && (chip_id & 0xF0) == 0x10) { /* LM86 */
1159 				name = "lm86";
1160 			}
1161 		}
1162 	} else
1163 	if ((address == 0x4C || address == 0x4D)
1164 	 && man_id == 0x41) { /* Analog Devices */
1165 		if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
1166 		 && (reg_config1 & 0x3F) == 0x00
1167 		 && reg_convrate <= 0x0A) {
1168 			name = "adm1032";
1169 			/* The ADM1032 supports PEC, but only if combined
1170 			   transactions are not used. */
1171 			if (i2c_check_functionality(adapter,
1172 						    I2C_FUNC_SMBUS_BYTE))
1173 				info->flags |= I2C_CLIENT_PEC;
1174 		} else
1175 		if (chip_id == 0x51 /* ADT7461 */
1176 		 && (reg_config1 & 0x1B) == 0x00
1177 		 && reg_convrate <= 0x0A) {
1178 			name = "adt7461";
1179 		} else
1180 		if (chip_id == 0x57 /* ADT7461A, NCT1008 */
1181 		 && (reg_config1 & 0x1B) == 0x00
1182 		 && reg_convrate <= 0x0A) {
1183 			name = "adt7461a";
1184 		}
1185 	} else
1186 	if (man_id == 0x4D) { /* Maxim */
1187 		int reg_emerg, reg_emerg2, reg_status2;
1188 
1189 		/*
1190 		 * We read MAX6659_REG_R_REMOTE_EMERG twice, and re-read
1191 		 * LM90_REG_R_MAN_ID in between. If MAX6659_REG_R_REMOTE_EMERG
1192 		 * exists, both readings will reflect the same value. Otherwise,
1193 		 * the readings will be different.
1194 		 */
1195 		if ((reg_emerg = i2c_smbus_read_byte_data(new_client,
1196 						MAX6659_REG_R_REMOTE_EMERG)) < 0
1197 		 || i2c_smbus_read_byte_data(new_client, LM90_REG_R_MAN_ID) < 0
1198 		 || (reg_emerg2 = i2c_smbus_read_byte_data(new_client,
1199 						MAX6659_REG_R_REMOTE_EMERG)) < 0
1200 		 || (reg_status2 = i2c_smbus_read_byte_data(new_client,
1201 						MAX6696_REG_R_STATUS2)) < 0)
1202 			return -ENODEV;
1203 
1204 		/*
1205 		 * The MAX6657, MAX6658 and MAX6659 do NOT have a chip_id
1206 		 * register. Reading from that address will return the last
1207 		 * read value, which in our case is those of the man_id
1208 		 * register. Likewise, the config1 register seems to lack a
1209 		 * low nibble, so the value will be those of the previous
1210 		 * read, so in our case those of the man_id register.
1211 		 * MAX6659 has a third set of upper temperature limit registers.
1212 		 * Those registers also return values on MAX6657 and MAX6658,
1213 		 * thus the only way to detect MAX6659 is by its address.
1214 		 * For this reason it will be mis-detected as MAX6657 if its
1215 		 * address is 0x4C.
1216 		 */
1217 		if (chip_id == man_id
1218 		 && (address == 0x4C || address == 0x4D || address == 0x4E)
1219 		 && (reg_config1 & 0x1F) == (man_id & 0x0F)
1220 		 && reg_convrate <= 0x09) {
1221 			if (address == 0x4C)
1222 				name = "max6657";
1223 			else
1224 				name = "max6659";
1225 		} else
1226 		/*
1227 		 * Even though MAX6695 and MAX6696 do not have a chip ID
1228 		 * register, reading it returns 0x01. Bit 4 of the config1
1229 		 * register is unused and should return zero when read. Bit 0 of
1230 		 * the status2 register is unused and should return zero when
1231 		 * read.
1232 		 *
1233 		 * MAX6695 and MAX6696 have an additional set of temperature
1234 		 * limit registers. We can detect those chips by checking if
1235 		 * one of those registers exists.
1236 		 */
1237 		if (chip_id == 0x01
1238 		 && (reg_config1 & 0x10) == 0x00
1239 		 && (reg_status2 & 0x01) == 0x00
1240 		 && reg_emerg == reg_emerg2
1241 		 && reg_convrate <= 0x07) {
1242 			name = "max6696";
1243 		} else
1244 		/*
1245 		 * The chip_id register of the MAX6680 and MAX6681 holds the
1246 		 * revision of the chip. The lowest bit of the config1 register
1247 		 * is unused and should return zero when read, so should the
1248 		 * second to last bit of config1 (software reset).
1249 		 */
1250 		if (chip_id == 0x01
1251 		 && (reg_config1 & 0x03) == 0x00
1252 		 && reg_convrate <= 0x07) {
1253 			name = "max6680";
1254 		} else
1255 		/*
1256 		 * The chip_id register of the MAX6646/6647/6649 holds the
1257 		 * revision of the chip. The lowest 6 bits of the config1
1258 		 * register are unused and should return zero when read.
1259 		 */
1260 		if (chip_id == 0x59
1261 		 && (reg_config1 & 0x3f) == 0x00
1262 		 && reg_convrate <= 0x07) {
1263 			name = "max6646";
1264 		}
1265 	} else
1266 	if (address == 0x4C
1267 	 && man_id == 0x5C) { /* Winbond/Nuvoton */
1268 		if ((reg_config1 & 0x2A) == 0x00
1269 		 && (reg_config2 & 0xF8) == 0x00) {
1270 			if (chip_id == 0x01 /* W83L771W/G */
1271 			 && reg_convrate <= 0x09) {
1272 				name = "w83l771";
1273 			} else
1274 			if ((chip_id & 0xFE) == 0x10 /* W83L771AWG/ASG */
1275 			 && reg_convrate <= 0x08) {
1276 				name = "w83l771";
1277 			}
1278 		}
1279 	} else
1280 	if (address >= 0x48 && address <= 0x4F
1281 	 && man_id == 0xA1) { /*  NXP Semiconductor/Philips */
1282 		if (chip_id == 0x00
1283 		 && (reg_config1 & 0x2A) == 0x00
1284 		 && (reg_config2 & 0xFE) == 0x00
1285 		 && reg_convrate <= 0x09) {
1286 			name = "sa56004";
1287 		}
1288 	}
1289 
1290 	if (!name) { /* identification failed */
1291 		dev_dbg(&adapter->dev,
1292 			"Unsupported chip at 0x%02x (man_id=0x%02X, "
1293 			"chip_id=0x%02X)\n", address, man_id, chip_id);
1294 		return -ENODEV;
1295 	}
1296 
1297 	strlcpy(info->type, name, I2C_NAME_SIZE);
1298 
1299 	return 0;
1300 }
1301 
1302 static void lm90_remove_files(struct i2c_client *client, struct lm90_data *data)
1303 {
1304 	if (data->flags & LM90_HAVE_TEMP3)
1305 		sysfs_remove_group(&client->dev.kobj, &lm90_temp3_group);
1306 	if (data->flags & LM90_HAVE_EMERGENCY_ALARM)
1307 		sysfs_remove_group(&client->dev.kobj,
1308 				   &lm90_emergency_alarm_group);
1309 	if (data->flags & LM90_HAVE_EMERGENCY)
1310 		sysfs_remove_group(&client->dev.kobj,
1311 				   &lm90_emergency_group);
1312 	if (data->flags & LM90_HAVE_OFFSET)
1313 		device_remove_file(&client->dev,
1314 				   &sensor_dev_attr_temp2_offset.dev_attr);
1315 	device_remove_file(&client->dev, &dev_attr_pec);
1316 	sysfs_remove_group(&client->dev.kobj, &lm90_group);
1317 }
1318 
1319 static void lm90_init_client(struct i2c_client *client)
1320 {
1321 	u8 config, convrate;
1322 	struct lm90_data *data = i2c_get_clientdata(client);
1323 
1324 	if (lm90_read_reg(client, LM90_REG_R_CONVRATE, &convrate) < 0) {
1325 		dev_warn(&client->dev, "Failed to read convrate register!\n");
1326 		convrate = LM90_DEF_CONVRATE_RVAL;
1327 	}
1328 	data->convrate_orig = convrate;
1329 
1330 	/*
1331 	 * Start the conversions.
1332 	 */
1333 	lm90_set_convrate(client, data, 500);	/* 500ms; 2Hz conversion rate */
1334 	if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) {
1335 		dev_warn(&client->dev, "Initialization failed!\n");
1336 		return;
1337 	}
1338 	data->config_orig = config;
1339 
1340 	/* Check Temperature Range Select */
1341 	if (data->kind == adt7461) {
1342 		if (config & 0x04)
1343 			data->flags |= LM90_FLAG_ADT7461_EXT;
1344 	}
1345 
1346 	/*
1347 	 * Put MAX6680/MAX8881 into extended resolution (bit 0x10,
1348 	 * 0.125 degree resolution) and range (0x08, extend range
1349 	 * to -64 degree) mode for the remote temperature sensor.
1350 	 */
1351 	if (data->kind == max6680)
1352 		config |= 0x18;
1353 
1354 	/*
1355 	 * Select external channel 0 for max6695/96
1356 	 */
1357 	if (data->kind == max6696)
1358 		config &= ~0x08;
1359 
1360 	config &= 0xBF;	/* run */
1361 	if (config != data->config_orig) /* Only write if changed */
1362 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config);
1363 }
1364 
1365 static int lm90_probe(struct i2c_client *new_client,
1366 		      const struct i2c_device_id *id)
1367 {
1368 	struct i2c_adapter *adapter = to_i2c_adapter(new_client->dev.parent);
1369 	struct lm90_data *data;
1370 	int err;
1371 
1372 	data = kzalloc(sizeof(struct lm90_data), GFP_KERNEL);
1373 	if (!data) {
1374 		err = -ENOMEM;
1375 		goto exit;
1376 	}
1377 	i2c_set_clientdata(new_client, data);
1378 	mutex_init(&data->update_lock);
1379 
1380 	/* Set the device type */
1381 	data->kind = id->driver_data;
1382 	if (data->kind == adm1032) {
1383 		if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
1384 			new_client->flags &= ~I2C_CLIENT_PEC;
1385 	}
1386 
1387 	/* Different devices have different alarm bits triggering the
1388 	 * ALERT# output */
1389 	data->alert_alarms = lm90_params[data->kind].alert_alarms;
1390 
1391 	/* Set chip capabilities */
1392 	data->flags = lm90_params[data->kind].flags;
1393 	data->reg_local_ext = lm90_params[data->kind].reg_local_ext;
1394 
1395 	/* Set maximum conversion rate */
1396 	data->max_convrate = lm90_params[data->kind].max_convrate;
1397 
1398 	/* Initialize the LM90 chip */
1399 	lm90_init_client(new_client);
1400 
1401 	/* Register sysfs hooks */
1402 	err = sysfs_create_group(&new_client->dev.kobj, &lm90_group);
1403 	if (err)
1404 		goto exit_free;
1405 	if (new_client->flags & I2C_CLIENT_PEC) {
1406 		err = device_create_file(&new_client->dev, &dev_attr_pec);
1407 		if (err)
1408 			goto exit_remove_files;
1409 	}
1410 	if (data->flags & LM90_HAVE_OFFSET) {
1411 		err = device_create_file(&new_client->dev,
1412 					&sensor_dev_attr_temp2_offset.dev_attr);
1413 		if (err)
1414 			goto exit_remove_files;
1415 	}
1416 	if (data->flags & LM90_HAVE_EMERGENCY) {
1417 		err = sysfs_create_group(&new_client->dev.kobj,
1418 					 &lm90_emergency_group);
1419 		if (err)
1420 			goto exit_remove_files;
1421 	}
1422 	if (data->flags & LM90_HAVE_EMERGENCY_ALARM) {
1423 		err = sysfs_create_group(&new_client->dev.kobj,
1424 					 &lm90_emergency_alarm_group);
1425 		if (err)
1426 			goto exit_remove_files;
1427 	}
1428 	if (data->flags & LM90_HAVE_TEMP3) {
1429 		err = sysfs_create_group(&new_client->dev.kobj,
1430 					 &lm90_temp3_group);
1431 		if (err)
1432 			goto exit_remove_files;
1433 	}
1434 
1435 	data->hwmon_dev = hwmon_device_register(&new_client->dev);
1436 	if (IS_ERR(data->hwmon_dev)) {
1437 		err = PTR_ERR(data->hwmon_dev);
1438 		goto exit_remove_files;
1439 	}
1440 
1441 	return 0;
1442 
1443 exit_remove_files:
1444 	lm90_remove_files(new_client, data);
1445 exit_free:
1446 	kfree(data);
1447 exit:
1448 	return err;
1449 }
1450 
1451 static int lm90_remove(struct i2c_client *client)
1452 {
1453 	struct lm90_data *data = i2c_get_clientdata(client);
1454 
1455 	hwmon_device_unregister(data->hwmon_dev);
1456 	lm90_remove_files(client, data);
1457 
1458 	/* Restore initial configuration */
1459 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
1460 				  data->convrate_orig);
1461 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
1462 				  data->config_orig);
1463 
1464 	kfree(data);
1465 	return 0;
1466 }
1467 
1468 static void lm90_alert(struct i2c_client *client, unsigned int flag)
1469 {
1470 	struct lm90_data *data = i2c_get_clientdata(client);
1471 	u8 config, alarms, alarms2 = 0;
1472 
1473 	lm90_read_reg(client, LM90_REG_R_STATUS, &alarms);
1474 
1475 	if (data->kind == max6696)
1476 		lm90_read_reg(client, MAX6696_REG_R_STATUS2, &alarms2);
1477 
1478 	if ((alarms & 0x7f) == 0 && (alarms2 & 0xfe) == 0) {
1479 		dev_info(&client->dev, "Everything OK\n");
1480 	} else {
1481 		if (alarms & 0x61)
1482 			dev_warn(&client->dev,
1483 				 "temp%d out of range, please check!\n", 1);
1484 		if (alarms & 0x1a)
1485 			dev_warn(&client->dev,
1486 				 "temp%d out of range, please check!\n", 2);
1487 		if (alarms & 0x04)
1488 			dev_warn(&client->dev,
1489 				 "temp%d diode open, please check!\n", 2);
1490 
1491 		if (alarms2 & 0x18)
1492 			dev_warn(&client->dev,
1493 				 "temp%d out of range, please check!\n", 3);
1494 
1495 		/* Disable ALERT# output, because these chips don't implement
1496 		  SMBus alert correctly; they should only hold the alert line
1497 		  low briefly. */
1498 		if ((data->flags & LM90_HAVE_BROKEN_ALERT)
1499 		 && (alarms & data->alert_alarms)) {
1500 			dev_dbg(&client->dev, "Disabling ALERT#\n");
1501 			lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
1502 			i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
1503 						  config | 0x80);
1504 		}
1505 	}
1506 }
1507 
1508 static struct i2c_driver lm90_driver = {
1509 	.class		= I2C_CLASS_HWMON,
1510 	.driver = {
1511 		.name	= "lm90",
1512 	},
1513 	.probe		= lm90_probe,
1514 	.remove		= lm90_remove,
1515 	.alert		= lm90_alert,
1516 	.id_table	= lm90_id,
1517 	.detect		= lm90_detect,
1518 	.address_list	= normal_i2c,
1519 };
1520 
1521 static int __init sensors_lm90_init(void)
1522 {
1523 	return i2c_add_driver(&lm90_driver);
1524 }
1525 
1526 static void __exit sensors_lm90_exit(void)
1527 {
1528 	i2c_del_driver(&lm90_driver);
1529 }
1530 
1531 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
1532 MODULE_DESCRIPTION("LM90/ADM1032 driver");
1533 MODULE_LICENSE("GPL");
1534 
1535 module_init(sensors_lm90_init);
1536 module_exit(sensors_lm90_exit);
1537