xref: /openbmc/linux/drivers/hwmon/lm90.c (revision bc000245)
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  * This driver also supports the G781 from GMT. This device is compatible
61  * with the ADM1032.
62  *
63  * This driver also supports TMP451 from Texas Instruments. This device is
64  * supported in both compatibility and extended mode. It's mostly compatible
65  * with ADT7461 except for local temperature low byte register and max
66  * conversion rate.
67  *
68  * Since the LM90 was the first chipset supported by this driver, most
69  * comments will refer to this chipset, but are actually general and
70  * concern all supported chipsets, unless mentioned otherwise.
71  *
72  * This program is free software; you can redistribute it and/or modify
73  * it under the terms of the GNU General Public License as published by
74  * the Free Software Foundation; either version 2 of the License, or
75  * (at your option) any later version.
76  *
77  * This program is distributed in the hope that it will be useful,
78  * but WITHOUT ANY WARRANTY; without even the implied warranty of
79  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
80  * GNU General Public License for more details.
81  *
82  * You should have received a copy of the GNU General Public License
83  * along with this program; if not, write to the Free Software
84  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
85  */
86 
87 #include <linux/module.h>
88 #include <linux/init.h>
89 #include <linux/slab.h>
90 #include <linux/jiffies.h>
91 #include <linux/i2c.h>
92 #include <linux/hwmon-sysfs.h>
93 #include <linux/hwmon.h>
94 #include <linux/err.h>
95 #include <linux/mutex.h>
96 #include <linux/sysfs.h>
97 #include <linux/interrupt.h>
98 #include <linux/regulator/consumer.h>
99 
100 /*
101  * Addresses to scan
102  * Address is fully defined internally and cannot be changed except for
103  * MAX6659, MAX6680 and MAX6681.
104  * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, ADT7461A, MAX6649,
105  * MAX6657, MAX6658, NCT1008 and W83L771 have address 0x4c.
106  * ADM1032-2, ADT7461-2, ADT7461A-2, LM89-1, LM99-1, MAX6646, and NCT1008D
107  * have address 0x4d.
108  * MAX6647 has address 0x4e.
109  * MAX6659 can have address 0x4c, 0x4d or 0x4e.
110  * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
111  * 0x4c, 0x4d or 0x4e.
112  * SA56004 can have address 0x48 through 0x4F.
113  */
114 
115 static const unsigned short normal_i2c[] = {
116 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x48, 0x49, 0x4a, 0x4b, 0x4c,
117 	0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
118 
119 enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
120 	max6646, w83l771, max6696, sa56004, g781, tmp451 };
121 
122 /*
123  * The LM90 registers
124  */
125 
126 #define LM90_REG_R_MAN_ID		0xFE
127 #define LM90_REG_R_CHIP_ID		0xFF
128 #define LM90_REG_R_CONFIG1		0x03
129 #define LM90_REG_W_CONFIG1		0x09
130 #define LM90_REG_R_CONFIG2		0xBF
131 #define LM90_REG_W_CONFIG2		0xBF
132 #define LM90_REG_R_CONVRATE		0x04
133 #define LM90_REG_W_CONVRATE		0x0A
134 #define LM90_REG_R_STATUS		0x02
135 #define LM90_REG_R_LOCAL_TEMP		0x00
136 #define LM90_REG_R_LOCAL_HIGH		0x05
137 #define LM90_REG_W_LOCAL_HIGH		0x0B
138 #define LM90_REG_R_LOCAL_LOW		0x06
139 #define LM90_REG_W_LOCAL_LOW		0x0C
140 #define LM90_REG_R_LOCAL_CRIT		0x20
141 #define LM90_REG_W_LOCAL_CRIT		0x20
142 #define LM90_REG_R_REMOTE_TEMPH		0x01
143 #define LM90_REG_R_REMOTE_TEMPL		0x10
144 #define LM90_REG_R_REMOTE_OFFSH		0x11
145 #define LM90_REG_W_REMOTE_OFFSH		0x11
146 #define LM90_REG_R_REMOTE_OFFSL		0x12
147 #define LM90_REG_W_REMOTE_OFFSL		0x12
148 #define LM90_REG_R_REMOTE_HIGHH		0x07
149 #define LM90_REG_W_REMOTE_HIGHH		0x0D
150 #define LM90_REG_R_REMOTE_HIGHL		0x13
151 #define LM90_REG_W_REMOTE_HIGHL		0x13
152 #define LM90_REG_R_REMOTE_LOWH		0x08
153 #define LM90_REG_W_REMOTE_LOWH		0x0E
154 #define LM90_REG_R_REMOTE_LOWL		0x14
155 #define LM90_REG_W_REMOTE_LOWL		0x14
156 #define LM90_REG_R_REMOTE_CRIT		0x19
157 #define LM90_REG_W_REMOTE_CRIT		0x19
158 #define LM90_REG_R_TCRIT_HYST		0x21
159 #define LM90_REG_W_TCRIT_HYST		0x21
160 
161 /* MAX6646/6647/6649/6657/6658/6659/6695/6696 registers */
162 
163 #define MAX6657_REG_R_LOCAL_TEMPL	0x11
164 #define MAX6696_REG_R_STATUS2		0x12
165 #define MAX6659_REG_R_REMOTE_EMERG	0x16
166 #define MAX6659_REG_W_REMOTE_EMERG	0x16
167 #define MAX6659_REG_R_LOCAL_EMERG	0x17
168 #define MAX6659_REG_W_LOCAL_EMERG	0x17
169 
170 /*  SA56004 registers */
171 
172 #define SA56004_REG_R_LOCAL_TEMPL 0x22
173 
174 #define LM90_DEF_CONVRATE_RVAL	6	/* Def conversion rate register value */
175 #define LM90_MAX_CONVRATE_MS	16000	/* Maximum conversion rate in ms */
176 
177 /* TMP451 registers */
178 #define TMP451_REG_R_LOCAL_TEMPL	0x15
179 
180 /*
181  * Device flags
182  */
183 #define LM90_FLAG_ADT7461_EXT	(1 << 0) /* ADT7461 extended mode	*/
184 /* Device features */
185 #define LM90_HAVE_OFFSET	(1 << 1) /* temperature offset register	*/
186 #define LM90_HAVE_REM_LIMIT_EXT	(1 << 3) /* extended remote limit	*/
187 #define LM90_HAVE_EMERGENCY	(1 << 4) /* 3rd upper (emergency) limit	*/
188 #define LM90_HAVE_EMERGENCY_ALARM (1 << 5)/* emergency alarm		*/
189 #define LM90_HAVE_TEMP3		(1 << 6) /* 3rd temperature sensor	*/
190 #define LM90_HAVE_BROKEN_ALERT	(1 << 7) /* Broken alert		*/
191 
192 /* LM90 status */
193 #define LM90_STATUS_LTHRM	(1 << 0) /* local THERM limit tripped */
194 #define LM90_STATUS_RTHRM	(1 << 1) /* remote THERM limit tripped */
195 #define LM90_STATUS_ROPEN	(1 << 2) /* remote is an open circuit */
196 #define LM90_STATUS_RLOW	(1 << 3) /* remote low temp limit tripped */
197 #define LM90_STATUS_RHIGH	(1 << 4) /* remote high temp limit tripped */
198 #define LM90_STATUS_LLOW	(1 << 5) /* local low temp limit tripped */
199 #define LM90_STATUS_LHIGH	(1 << 6) /* local high temp limit tripped */
200 
201 #define MAX6696_STATUS2_R2THRM	(1 << 1) /* remote2 THERM limit tripped */
202 #define MAX6696_STATUS2_R2OPEN	(1 << 2) /* remote2 is an open circuit */
203 #define MAX6696_STATUS2_R2LOW	(1 << 3) /* remote2 low temp limit tripped */
204 #define MAX6696_STATUS2_R2HIGH	(1 << 4) /* remote2 high temp limit tripped */
205 #define MAX6696_STATUS2_ROT2	(1 << 5) /* remote emergency limit tripped */
206 #define MAX6696_STATUS2_R2OT2	(1 << 6) /* remote2 emergency limit tripped */
207 #define MAX6696_STATUS2_LOT2	(1 << 7) /* local emergency limit tripped */
208 
209 /*
210  * Driver data (common to all clients)
211  */
212 
213 static const struct i2c_device_id lm90_id[] = {
214 	{ "adm1032", adm1032 },
215 	{ "adt7461", adt7461 },
216 	{ "adt7461a", adt7461 },
217 	{ "g781", g781 },
218 	{ "lm90", lm90 },
219 	{ "lm86", lm86 },
220 	{ "lm89", lm86 },
221 	{ "lm99", lm99 },
222 	{ "max6646", max6646 },
223 	{ "max6647", max6646 },
224 	{ "max6649", max6646 },
225 	{ "max6657", max6657 },
226 	{ "max6658", max6657 },
227 	{ "max6659", max6659 },
228 	{ "max6680", max6680 },
229 	{ "max6681", max6680 },
230 	{ "max6695", max6696 },
231 	{ "max6696", max6696 },
232 	{ "nct1008", adt7461 },
233 	{ "w83l771", w83l771 },
234 	{ "sa56004", sa56004 },
235 	{ "tmp451", tmp451 },
236 	{ }
237 };
238 MODULE_DEVICE_TABLE(i2c, lm90_id);
239 
240 /*
241  * chip type specific parameters
242  */
243 struct lm90_params {
244 	u32 flags;		/* Capabilities */
245 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
246 				/* Upper 8 bits for max6695/96 */
247 	u8 max_convrate;	/* Maximum conversion rate register value */
248 	u8 reg_local_ext;	/* Extended local temp register (optional) */
249 };
250 
251 static const struct lm90_params lm90_params[] = {
252 	[adm1032] = {
253 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
254 		  | LM90_HAVE_BROKEN_ALERT,
255 		.alert_alarms = 0x7c,
256 		.max_convrate = 10,
257 	},
258 	[adt7461] = {
259 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
260 		  | LM90_HAVE_BROKEN_ALERT,
261 		.alert_alarms = 0x7c,
262 		.max_convrate = 10,
263 	},
264 	[g781] = {
265 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
266 		  | LM90_HAVE_BROKEN_ALERT,
267 		.alert_alarms = 0x7c,
268 		.max_convrate = 8,
269 	},
270 	[lm86] = {
271 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
272 		.alert_alarms = 0x7b,
273 		.max_convrate = 9,
274 	},
275 	[lm90] = {
276 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
277 		.alert_alarms = 0x7b,
278 		.max_convrate = 9,
279 	},
280 	[lm99] = {
281 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
282 		.alert_alarms = 0x7b,
283 		.max_convrate = 9,
284 	},
285 	[max6646] = {
286 		.alert_alarms = 0x7c,
287 		.max_convrate = 6,
288 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
289 	},
290 	[max6657] = {
291 		.alert_alarms = 0x7c,
292 		.max_convrate = 8,
293 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
294 	},
295 	[max6659] = {
296 		.flags = LM90_HAVE_EMERGENCY,
297 		.alert_alarms = 0x7c,
298 		.max_convrate = 8,
299 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
300 	},
301 	[max6680] = {
302 		.flags = LM90_HAVE_OFFSET,
303 		.alert_alarms = 0x7c,
304 		.max_convrate = 7,
305 	},
306 	[max6696] = {
307 		.flags = LM90_HAVE_EMERGENCY
308 		  | LM90_HAVE_EMERGENCY_ALARM | LM90_HAVE_TEMP3,
309 		.alert_alarms = 0x1c7c,
310 		.max_convrate = 6,
311 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
312 	},
313 	[w83l771] = {
314 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
315 		.alert_alarms = 0x7c,
316 		.max_convrate = 8,
317 	},
318 	[sa56004] = {
319 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
320 		.alert_alarms = 0x7b,
321 		.max_convrate = 9,
322 		.reg_local_ext = SA56004_REG_R_LOCAL_TEMPL,
323 	},
324 	[tmp451] = {
325 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
326 		  | LM90_HAVE_BROKEN_ALERT,
327 		.alert_alarms = 0x7c,
328 		.max_convrate = 9,
329 		.reg_local_ext = TMP451_REG_R_LOCAL_TEMPL,
330 	}
331 };
332 
333 /*
334  * TEMP8 register index
335  */
336 enum lm90_temp8_reg_index {
337 	LOCAL_LOW = 0,
338 	LOCAL_HIGH,
339 	LOCAL_CRIT,
340 	REMOTE_CRIT,
341 	LOCAL_EMERG,	/* max6659 and max6695/96 */
342 	REMOTE_EMERG,	/* max6659 and max6695/96 */
343 	REMOTE2_CRIT,	/* max6695/96 only */
344 	REMOTE2_EMERG,	/* max6695/96 only */
345 	TEMP8_REG_NUM
346 };
347 
348 /*
349  * TEMP11 register index
350  */
351 enum lm90_temp11_reg_index {
352 	REMOTE_TEMP = 0,
353 	REMOTE_LOW,
354 	REMOTE_HIGH,
355 	REMOTE_OFFSET,	/* except max6646, max6657/58/59, and max6695/96 */
356 	LOCAL_TEMP,
357 	REMOTE2_TEMP,	/* max6695/96 only */
358 	REMOTE2_LOW,	/* max6695/96 only */
359 	REMOTE2_HIGH,	/* max6695/96 only */
360 	TEMP11_REG_NUM
361 };
362 
363 /*
364  * Client data (each client gets its own)
365  */
366 
367 struct lm90_data {
368 	struct device *hwmon_dev;
369 	struct mutex update_lock;
370 	struct regulator *regulator;
371 	char valid; /* zero until following fields are valid */
372 	unsigned long last_updated; /* in jiffies */
373 	int kind;
374 	u32 flags;
375 
376 	int update_interval;	/* in milliseconds */
377 
378 	u8 config_orig;		/* Original configuration register value */
379 	u8 convrate_orig;	/* Original conversion rate register value */
380 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
381 				/* Upper 8 bits for max6695/96 */
382 	u8 max_convrate;	/* Maximum conversion rate */
383 	u8 reg_local_ext;	/* local extension register offset */
384 
385 	/* registers values */
386 	s8 temp8[TEMP8_REG_NUM];
387 	s16 temp11[TEMP11_REG_NUM];
388 	u8 temp_hyst;
389 	u16 alarms; /* bitvector (upper 8 bits for max6695/96) */
390 };
391 
392 /*
393  * Support functions
394  */
395 
396 /*
397  * The ADM1032 supports PEC but not on write byte transactions, so we need
398  * to explicitly ask for a transaction without PEC.
399  */
400 static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value)
401 {
402 	return i2c_smbus_xfer(client->adapter, client->addr,
403 			      client->flags & ~I2C_CLIENT_PEC,
404 			      I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
405 }
406 
407 /*
408  * It is assumed that client->update_lock is held (unless we are in
409  * detection or initialization steps). This matters when PEC is enabled,
410  * because we don't want the address pointer to change between the write
411  * byte and the read byte transactions.
412  */
413 static int lm90_read_reg(struct i2c_client *client, u8 reg, u8 *value)
414 {
415 	int err;
416 
417 	if (client->flags & I2C_CLIENT_PEC) {
418 		err = adm1032_write_byte(client, reg);
419 		if (err >= 0)
420 			err = i2c_smbus_read_byte(client);
421 	} else
422 		err = i2c_smbus_read_byte_data(client, reg);
423 
424 	if (err < 0) {
425 		dev_warn(&client->dev, "Register %#02x read failed (%d)\n",
426 			 reg, err);
427 		return err;
428 	}
429 	*value = err;
430 
431 	return 0;
432 }
433 
434 static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl, u16 *value)
435 {
436 	int err;
437 	u8 oldh, newh, l;
438 
439 	/*
440 	 * There is a trick here. We have to read two registers to have the
441 	 * sensor temperature, but we have to beware a conversion could occur
442 	 * between the readings. The datasheet says we should either use
443 	 * the one-shot conversion register, which we don't want to do
444 	 * (disables hardware monitoring) or monitor the busy bit, which is
445 	 * impossible (we can't read the values and monitor that bit at the
446 	 * exact same time). So the solution used here is to read the high
447 	 * byte once, then the low byte, then the high byte again. If the new
448 	 * high byte matches the old one, then we have a valid reading. Else
449 	 * we have to read the low byte again, and now we believe we have a
450 	 * correct reading.
451 	 */
452 	if ((err = lm90_read_reg(client, regh, &oldh))
453 	 || (err = lm90_read_reg(client, regl, &l))
454 	 || (err = lm90_read_reg(client, regh, &newh)))
455 		return err;
456 	if (oldh != newh) {
457 		err = lm90_read_reg(client, regl, &l);
458 		if (err)
459 			return err;
460 	}
461 	*value = (newh << 8) | l;
462 
463 	return 0;
464 }
465 
466 /*
467  * client->update_lock must be held when calling this function (unless we are
468  * in detection or initialization steps), and while a remote channel other
469  * than channel 0 is selected. Also, calling code must make sure to re-select
470  * external channel 0 before releasing the lock. This is necessary because
471  * various registers have different meanings as a result of selecting a
472  * non-default remote channel.
473  */
474 static inline void lm90_select_remote_channel(struct i2c_client *client,
475 					      struct lm90_data *data,
476 					      int channel)
477 {
478 	u8 config;
479 
480 	if (data->kind == max6696) {
481 		lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
482 		config &= ~0x08;
483 		if (channel)
484 			config |= 0x08;
485 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
486 					  config);
487 	}
488 }
489 
490 /*
491  * Set conversion rate.
492  * client->update_lock must be held when calling this function (unless we are
493  * in detection or initialization steps).
494  */
495 static void lm90_set_convrate(struct i2c_client *client, struct lm90_data *data,
496 			      unsigned int interval)
497 {
498 	int i;
499 	unsigned int update_interval;
500 
501 	/* Shift calculations to avoid rounding errors */
502 	interval <<= 6;
503 
504 	/* find the nearest update rate */
505 	for (i = 0, update_interval = LM90_MAX_CONVRATE_MS << 6;
506 	     i < data->max_convrate; i++, update_interval >>= 1)
507 		if (interval >= update_interval * 3 / 4)
508 			break;
509 
510 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, i);
511 	data->update_interval = DIV_ROUND_CLOSEST(update_interval, 64);
512 }
513 
514 static struct lm90_data *lm90_update_device(struct device *dev)
515 {
516 	struct i2c_client *client = to_i2c_client(dev);
517 	struct lm90_data *data = i2c_get_clientdata(client);
518 	unsigned long next_update;
519 
520 	mutex_lock(&data->update_lock);
521 
522 	next_update = data->last_updated +
523 		      msecs_to_jiffies(data->update_interval);
524 	if (time_after(jiffies, next_update) || !data->valid) {
525 		u8 h, l;
526 		u8 alarms;
527 
528 		dev_dbg(&client->dev, "Updating lm90 data.\n");
529 		lm90_read_reg(client, LM90_REG_R_LOCAL_LOW,
530 			      &data->temp8[LOCAL_LOW]);
531 		lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH,
532 			      &data->temp8[LOCAL_HIGH]);
533 		lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT,
534 			      &data->temp8[LOCAL_CRIT]);
535 		lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT,
536 			      &data->temp8[REMOTE_CRIT]);
537 		lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
538 
539 		if (data->reg_local_ext) {
540 			lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
541 				    data->reg_local_ext,
542 				    &data->temp11[LOCAL_TEMP]);
543 		} else {
544 			if (lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP,
545 					  &h) == 0)
546 				data->temp11[LOCAL_TEMP] = h << 8;
547 		}
548 		lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
549 			    LM90_REG_R_REMOTE_TEMPL,
550 			    &data->temp11[REMOTE_TEMP]);
551 
552 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h) == 0) {
553 			data->temp11[REMOTE_LOW] = h << 8;
554 			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
555 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL,
556 					  &l) == 0)
557 				data->temp11[REMOTE_LOW] |= l;
558 		}
559 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h) == 0) {
560 			data->temp11[REMOTE_HIGH] = h << 8;
561 			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
562 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL,
563 					  &l) == 0)
564 				data->temp11[REMOTE_HIGH] |= l;
565 		}
566 
567 		if (data->flags & LM90_HAVE_OFFSET) {
568 			if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
569 					  &h) == 0
570 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,
571 					  &l) == 0)
572 				data->temp11[REMOTE_OFFSET] = (h << 8) | l;
573 		}
574 		if (data->flags & LM90_HAVE_EMERGENCY) {
575 			lm90_read_reg(client, MAX6659_REG_R_LOCAL_EMERG,
576 				      &data->temp8[LOCAL_EMERG]);
577 			lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
578 				      &data->temp8[REMOTE_EMERG]);
579 		}
580 		lm90_read_reg(client, LM90_REG_R_STATUS, &alarms);
581 		data->alarms = alarms;	/* save as 16 bit value */
582 
583 		if (data->kind == max6696) {
584 			lm90_select_remote_channel(client, data, 1);
585 			lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT,
586 				      &data->temp8[REMOTE2_CRIT]);
587 			lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
588 				      &data->temp8[REMOTE2_EMERG]);
589 			lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
590 				    LM90_REG_R_REMOTE_TEMPL,
591 				    &data->temp11[REMOTE2_TEMP]);
592 			if (!lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h))
593 				data->temp11[REMOTE2_LOW] = h << 8;
594 			if (!lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h))
595 				data->temp11[REMOTE2_HIGH] = h << 8;
596 			lm90_select_remote_channel(client, data, 0);
597 
598 			if (!lm90_read_reg(client, MAX6696_REG_R_STATUS2,
599 					   &alarms))
600 				data->alarms |= alarms << 8;
601 		}
602 
603 		/*
604 		 * Re-enable ALERT# output if it was originally enabled and
605 		 * relevant alarms are all clear
606 		 */
607 		if ((data->config_orig & 0x80) == 0
608 		 && (data->alarms & data->alert_alarms) == 0) {
609 			u8 config;
610 
611 			lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
612 			if (config & 0x80) {
613 				dev_dbg(&client->dev, "Re-enabling ALERT#\n");
614 				i2c_smbus_write_byte_data(client,
615 							  LM90_REG_W_CONFIG1,
616 							  config & ~0x80);
617 			}
618 		}
619 
620 		data->last_updated = jiffies;
621 		data->valid = 1;
622 	}
623 
624 	mutex_unlock(&data->update_lock);
625 
626 	return data;
627 }
628 
629 /*
630  * Conversions
631  * For local temperatures and limits, critical limits and the hysteresis
632  * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
633  * For remote temperatures and limits, it uses signed 11-bit values with
634  * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.  Some
635  * Maxim chips use unsigned values.
636  */
637 
638 static inline int temp_from_s8(s8 val)
639 {
640 	return val * 1000;
641 }
642 
643 static inline int temp_from_u8(u8 val)
644 {
645 	return val * 1000;
646 }
647 
648 static inline int temp_from_s16(s16 val)
649 {
650 	return val / 32 * 125;
651 }
652 
653 static inline int temp_from_u16(u16 val)
654 {
655 	return val / 32 * 125;
656 }
657 
658 static s8 temp_to_s8(long val)
659 {
660 	if (val <= -128000)
661 		return -128;
662 	if (val >= 127000)
663 		return 127;
664 	if (val < 0)
665 		return (val - 500) / 1000;
666 	return (val + 500) / 1000;
667 }
668 
669 static u8 temp_to_u8(long val)
670 {
671 	if (val <= 0)
672 		return 0;
673 	if (val >= 255000)
674 		return 255;
675 	return (val + 500) / 1000;
676 }
677 
678 static s16 temp_to_s16(long val)
679 {
680 	if (val <= -128000)
681 		return 0x8000;
682 	if (val >= 127875)
683 		return 0x7FE0;
684 	if (val < 0)
685 		return (val - 62) / 125 * 32;
686 	return (val + 62) / 125 * 32;
687 }
688 
689 static u8 hyst_to_reg(long val)
690 {
691 	if (val <= 0)
692 		return 0;
693 	if (val >= 30500)
694 		return 31;
695 	return (val + 500) / 1000;
696 }
697 
698 /*
699  * ADT7461 in compatibility mode is almost identical to LM90 except that
700  * attempts to write values that are outside the range 0 < temp < 127 are
701  * treated as the boundary value.
702  *
703  * ADT7461 in "extended mode" operation uses unsigned integers offset by
704  * 64 (e.g., 0 -> -64 degC).  The range is restricted to -64..191 degC.
705  */
706 static inline int temp_from_u8_adt7461(struct lm90_data *data, u8 val)
707 {
708 	if (data->flags & LM90_FLAG_ADT7461_EXT)
709 		return (val - 64) * 1000;
710 	else
711 		return temp_from_s8(val);
712 }
713 
714 static inline int temp_from_u16_adt7461(struct lm90_data *data, u16 val)
715 {
716 	if (data->flags & LM90_FLAG_ADT7461_EXT)
717 		return (val - 0x4000) / 64 * 250;
718 	else
719 		return temp_from_s16(val);
720 }
721 
722 static u8 temp_to_u8_adt7461(struct lm90_data *data, long val)
723 {
724 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
725 		if (val <= -64000)
726 			return 0;
727 		if (val >= 191000)
728 			return 0xFF;
729 		return (val + 500 + 64000) / 1000;
730 	} else {
731 		if (val <= 0)
732 			return 0;
733 		if (val >= 127000)
734 			return 127;
735 		return (val + 500) / 1000;
736 	}
737 }
738 
739 static u16 temp_to_u16_adt7461(struct lm90_data *data, long val)
740 {
741 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
742 		if (val <= -64000)
743 			return 0;
744 		if (val >= 191750)
745 			return 0xFFC0;
746 		return (val + 64000 + 125) / 250 * 64;
747 	} else {
748 		if (val <= 0)
749 			return 0;
750 		if (val >= 127750)
751 			return 0x7FC0;
752 		return (val + 125) / 250 * 64;
753 	}
754 }
755 
756 /*
757  * Sysfs stuff
758  */
759 
760 static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
761 			  char *buf)
762 {
763 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
764 	struct lm90_data *data = lm90_update_device(dev);
765 	int temp;
766 
767 	if (data->kind == adt7461 || data->kind == tmp451)
768 		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
769 	else if (data->kind == max6646)
770 		temp = temp_from_u8(data->temp8[attr->index]);
771 	else
772 		temp = temp_from_s8(data->temp8[attr->index]);
773 
774 	/* +16 degrees offset for temp2 for the LM99 */
775 	if (data->kind == lm99 && attr->index == 3)
776 		temp += 16000;
777 
778 	return sprintf(buf, "%d\n", temp);
779 }
780 
781 static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
782 			 const char *buf, size_t count)
783 {
784 	static const u8 reg[TEMP8_REG_NUM] = {
785 		LM90_REG_W_LOCAL_LOW,
786 		LM90_REG_W_LOCAL_HIGH,
787 		LM90_REG_W_LOCAL_CRIT,
788 		LM90_REG_W_REMOTE_CRIT,
789 		MAX6659_REG_W_LOCAL_EMERG,
790 		MAX6659_REG_W_REMOTE_EMERG,
791 		LM90_REG_W_REMOTE_CRIT,
792 		MAX6659_REG_W_REMOTE_EMERG,
793 	};
794 
795 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
796 	struct i2c_client *client = to_i2c_client(dev);
797 	struct lm90_data *data = i2c_get_clientdata(client);
798 	int nr = attr->index;
799 	long val;
800 	int err;
801 
802 	err = kstrtol(buf, 10, &val);
803 	if (err < 0)
804 		return err;
805 
806 	/* +16 degrees offset for temp2 for the LM99 */
807 	if (data->kind == lm99 && attr->index == 3)
808 		val -= 16000;
809 
810 	mutex_lock(&data->update_lock);
811 	if (data->kind == adt7461 || data->kind == tmp451)
812 		data->temp8[nr] = temp_to_u8_adt7461(data, val);
813 	else if (data->kind == max6646)
814 		data->temp8[nr] = temp_to_u8(val);
815 	else
816 		data->temp8[nr] = temp_to_s8(val);
817 
818 	lm90_select_remote_channel(client, data, nr >= 6);
819 	i2c_smbus_write_byte_data(client, reg[nr], data->temp8[nr]);
820 	lm90_select_remote_channel(client, data, 0);
821 
822 	mutex_unlock(&data->update_lock);
823 	return count;
824 }
825 
826 static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
827 			   char *buf)
828 {
829 	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
830 	struct lm90_data *data = lm90_update_device(dev);
831 	int temp;
832 
833 	if (data->kind == adt7461 || data->kind == tmp451)
834 		temp = temp_from_u16_adt7461(data, data->temp11[attr->index]);
835 	else if (data->kind == max6646)
836 		temp = temp_from_u16(data->temp11[attr->index]);
837 	else
838 		temp = temp_from_s16(data->temp11[attr->index]);
839 
840 	/* +16 degrees offset for temp2 for the LM99 */
841 	if (data->kind == lm99 &&  attr->index <= 2)
842 		temp += 16000;
843 
844 	return sprintf(buf, "%d\n", temp);
845 }
846 
847 static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
848 			  const char *buf, size_t count)
849 {
850 	struct {
851 		u8 high;
852 		u8 low;
853 		int channel;
854 	} reg[5] = {
855 		{ LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL, 0 },
856 		{ LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 0 },
857 		{ LM90_REG_W_REMOTE_OFFSH, LM90_REG_W_REMOTE_OFFSL, 0 },
858 		{ LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL, 1 },
859 		{ LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 1 }
860 	};
861 
862 	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
863 	struct i2c_client *client = to_i2c_client(dev);
864 	struct lm90_data *data = i2c_get_clientdata(client);
865 	int nr = attr->nr;
866 	int index = attr->index;
867 	long val;
868 	int err;
869 
870 	err = kstrtol(buf, 10, &val);
871 	if (err < 0)
872 		return err;
873 
874 	/* +16 degrees offset for temp2 for the LM99 */
875 	if (data->kind == lm99 && index <= 2)
876 		val -= 16000;
877 
878 	mutex_lock(&data->update_lock);
879 	if (data->kind == adt7461 || data->kind == tmp451)
880 		data->temp11[index] = temp_to_u16_adt7461(data, val);
881 	else if (data->kind == max6646)
882 		data->temp11[index] = temp_to_u8(val) << 8;
883 	else if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
884 		data->temp11[index] = temp_to_s16(val);
885 	else
886 		data->temp11[index] = temp_to_s8(val) << 8;
887 
888 	lm90_select_remote_channel(client, data, reg[nr].channel);
889 	i2c_smbus_write_byte_data(client, reg[nr].high,
890 				  data->temp11[index] >> 8);
891 	if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
892 		i2c_smbus_write_byte_data(client, reg[nr].low,
893 					  data->temp11[index] & 0xff);
894 	lm90_select_remote_channel(client, data, 0);
895 
896 	mutex_unlock(&data->update_lock);
897 	return count;
898 }
899 
900 static ssize_t show_temphyst(struct device *dev,
901 			     struct device_attribute *devattr,
902 			     char *buf)
903 {
904 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
905 	struct lm90_data *data = lm90_update_device(dev);
906 	int temp;
907 
908 	if (data->kind == adt7461 || data->kind == tmp451)
909 		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
910 	else if (data->kind == max6646)
911 		temp = temp_from_u8(data->temp8[attr->index]);
912 	else
913 		temp = temp_from_s8(data->temp8[attr->index]);
914 
915 	/* +16 degrees offset for temp2 for the LM99 */
916 	if (data->kind == lm99 && attr->index == 3)
917 		temp += 16000;
918 
919 	return sprintf(buf, "%d\n", temp - temp_from_s8(data->temp_hyst));
920 }
921 
922 static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
923 			    const char *buf, size_t count)
924 {
925 	struct i2c_client *client = to_i2c_client(dev);
926 	struct lm90_data *data = i2c_get_clientdata(client);
927 	long val;
928 	int err;
929 	int temp;
930 
931 	err = kstrtol(buf, 10, &val);
932 	if (err < 0)
933 		return err;
934 
935 	mutex_lock(&data->update_lock);
936 	if (data->kind == adt7461 || data->kind == tmp451)
937 		temp = temp_from_u8_adt7461(data, data->temp8[LOCAL_CRIT]);
938 	else if (data->kind == max6646)
939 		temp = temp_from_u8(data->temp8[LOCAL_CRIT]);
940 	else
941 		temp = temp_from_s8(data->temp8[LOCAL_CRIT]);
942 
943 	data->temp_hyst = hyst_to_reg(temp - val);
944 	i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
945 				  data->temp_hyst);
946 	mutex_unlock(&data->update_lock);
947 	return count;
948 }
949 
950 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
951 			   char *buf)
952 {
953 	struct lm90_data *data = lm90_update_device(dev);
954 	return sprintf(buf, "%d\n", data->alarms);
955 }
956 
957 static ssize_t show_alarm(struct device *dev, struct device_attribute
958 			  *devattr, char *buf)
959 {
960 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
961 	struct lm90_data *data = lm90_update_device(dev);
962 	int bitnr = attr->index;
963 
964 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
965 }
966 
967 static ssize_t show_update_interval(struct device *dev,
968 				    struct device_attribute *attr, char *buf)
969 {
970 	struct lm90_data *data = dev_get_drvdata(dev);
971 
972 	return sprintf(buf, "%u\n", data->update_interval);
973 }
974 
975 static ssize_t set_update_interval(struct device *dev,
976 				   struct device_attribute *attr,
977 				   const char *buf, size_t count)
978 {
979 	struct i2c_client *client = to_i2c_client(dev);
980 	struct lm90_data *data = i2c_get_clientdata(client);
981 	unsigned long val;
982 	int err;
983 
984 	err = kstrtoul(buf, 10, &val);
985 	if (err)
986 		return err;
987 
988 	mutex_lock(&data->update_lock);
989 	lm90_set_convrate(client, data, clamp_val(val, 0, 100000));
990 	mutex_unlock(&data->update_lock);
991 
992 	return count;
993 }
994 
995 static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp11, NULL,
996 	0, LOCAL_TEMP);
997 static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp11, NULL,
998 	0, REMOTE_TEMP);
999 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
1000 	set_temp8, LOCAL_LOW);
1001 static SENSOR_DEVICE_ATTR_2(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
1002 	set_temp11, 0, REMOTE_LOW);
1003 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
1004 	set_temp8, LOCAL_HIGH);
1005 static SENSOR_DEVICE_ATTR_2(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
1006 	set_temp11, 1, REMOTE_HIGH);
1007 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
1008 	set_temp8, LOCAL_CRIT);
1009 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
1010 	set_temp8, REMOTE_CRIT);
1011 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
1012 	set_temphyst, LOCAL_CRIT);
1013 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL,
1014 	REMOTE_CRIT);
1015 static SENSOR_DEVICE_ATTR_2(temp2_offset, S_IWUSR | S_IRUGO, show_temp11,
1016 	set_temp11, 2, REMOTE_OFFSET);
1017 
1018 /* Individual alarm files */
1019 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
1020 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
1021 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
1022 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
1023 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
1024 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 5);
1025 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
1026 /* Raw alarm file for compatibility */
1027 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
1028 
1029 static DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR, show_update_interval,
1030 		   set_update_interval);
1031 
1032 static struct attribute *lm90_attributes[] = {
1033 	&sensor_dev_attr_temp1_input.dev_attr.attr,
1034 	&sensor_dev_attr_temp2_input.dev_attr.attr,
1035 	&sensor_dev_attr_temp1_min.dev_attr.attr,
1036 	&sensor_dev_attr_temp2_min.dev_attr.attr,
1037 	&sensor_dev_attr_temp1_max.dev_attr.attr,
1038 	&sensor_dev_attr_temp2_max.dev_attr.attr,
1039 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
1040 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
1041 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
1042 	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
1043 
1044 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
1045 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
1046 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
1047 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
1048 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
1049 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
1050 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
1051 	&dev_attr_alarms.attr,
1052 	&dev_attr_update_interval.attr,
1053 	NULL
1054 };
1055 
1056 static const struct attribute_group lm90_group = {
1057 	.attrs = lm90_attributes,
1058 };
1059 
1060 /*
1061  * Additional attributes for devices with emergency sensors
1062  */
1063 static SENSOR_DEVICE_ATTR(temp1_emergency, S_IWUSR | S_IRUGO, show_temp8,
1064 	set_temp8, LOCAL_EMERG);
1065 static SENSOR_DEVICE_ATTR(temp2_emergency, S_IWUSR | S_IRUGO, show_temp8,
1066 	set_temp8, REMOTE_EMERG);
1067 static SENSOR_DEVICE_ATTR(temp1_emergency_hyst, S_IRUGO, show_temphyst,
1068 			  NULL, LOCAL_EMERG);
1069 static SENSOR_DEVICE_ATTR(temp2_emergency_hyst, S_IRUGO, show_temphyst,
1070 			  NULL, REMOTE_EMERG);
1071 
1072 static struct attribute *lm90_emergency_attributes[] = {
1073 	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
1074 	&sensor_dev_attr_temp2_emergency.dev_attr.attr,
1075 	&sensor_dev_attr_temp1_emergency_hyst.dev_attr.attr,
1076 	&sensor_dev_attr_temp2_emergency_hyst.dev_attr.attr,
1077 	NULL
1078 };
1079 
1080 static const struct attribute_group lm90_emergency_group = {
1081 	.attrs = lm90_emergency_attributes,
1082 };
1083 
1084 static SENSOR_DEVICE_ATTR(temp1_emergency_alarm, S_IRUGO, show_alarm, NULL, 15);
1085 static SENSOR_DEVICE_ATTR(temp2_emergency_alarm, S_IRUGO, show_alarm, NULL, 13);
1086 
1087 static struct attribute *lm90_emergency_alarm_attributes[] = {
1088 	&sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
1089 	&sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
1090 	NULL
1091 };
1092 
1093 static const struct attribute_group lm90_emergency_alarm_group = {
1094 	.attrs = lm90_emergency_alarm_attributes,
1095 };
1096 
1097 /*
1098  * Additional attributes for devices with 3 temperature sensors
1099  */
1100 static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp11, NULL,
1101 	0, REMOTE2_TEMP);
1102 static SENSOR_DEVICE_ATTR_2(temp3_min, S_IWUSR | S_IRUGO, show_temp11,
1103 	set_temp11, 3, REMOTE2_LOW);
1104 static SENSOR_DEVICE_ATTR_2(temp3_max, S_IWUSR | S_IRUGO, show_temp11,
1105 	set_temp11, 4, REMOTE2_HIGH);
1106 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp8,
1107 	set_temp8, REMOTE2_CRIT);
1108 static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO, show_temphyst, NULL,
1109 	REMOTE2_CRIT);
1110 static SENSOR_DEVICE_ATTR(temp3_emergency, S_IWUSR | S_IRUGO, show_temp8,
1111 	set_temp8, REMOTE2_EMERG);
1112 static SENSOR_DEVICE_ATTR(temp3_emergency_hyst, S_IRUGO, show_temphyst,
1113 			  NULL, REMOTE2_EMERG);
1114 
1115 static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
1116 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 10);
1117 static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_alarm, NULL, 11);
1118 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 12);
1119 static SENSOR_DEVICE_ATTR(temp3_emergency_alarm, S_IRUGO, show_alarm, NULL, 14);
1120 
1121 static struct attribute *lm90_temp3_attributes[] = {
1122 	&sensor_dev_attr_temp3_input.dev_attr.attr,
1123 	&sensor_dev_attr_temp3_min.dev_attr.attr,
1124 	&sensor_dev_attr_temp3_max.dev_attr.attr,
1125 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
1126 	&sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
1127 	&sensor_dev_attr_temp3_emergency.dev_attr.attr,
1128 	&sensor_dev_attr_temp3_emergency_hyst.dev_attr.attr,
1129 
1130 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
1131 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
1132 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
1133 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
1134 	&sensor_dev_attr_temp3_emergency_alarm.dev_attr.attr,
1135 	NULL
1136 };
1137 
1138 static const struct attribute_group lm90_temp3_group = {
1139 	.attrs = lm90_temp3_attributes,
1140 };
1141 
1142 /* pec used for ADM1032 only */
1143 static ssize_t show_pec(struct device *dev, struct device_attribute *dummy,
1144 			char *buf)
1145 {
1146 	struct i2c_client *client = to_i2c_client(dev);
1147 	return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
1148 }
1149 
1150 static ssize_t set_pec(struct device *dev, struct device_attribute *dummy,
1151 		       const char *buf, size_t count)
1152 {
1153 	struct i2c_client *client = to_i2c_client(dev);
1154 	long val;
1155 	int err;
1156 
1157 	err = kstrtol(buf, 10, &val);
1158 	if (err < 0)
1159 		return err;
1160 
1161 	switch (val) {
1162 	case 0:
1163 		client->flags &= ~I2C_CLIENT_PEC;
1164 		break;
1165 	case 1:
1166 		client->flags |= I2C_CLIENT_PEC;
1167 		break;
1168 	default:
1169 		return -EINVAL;
1170 	}
1171 
1172 	return count;
1173 }
1174 
1175 static DEVICE_ATTR(pec, S_IWUSR | S_IRUGO, show_pec, set_pec);
1176 
1177 /*
1178  * Real code
1179  */
1180 
1181 /* Return 0 if detection is successful, -ENODEV otherwise */
1182 static int lm90_detect(struct i2c_client *client,
1183 		       struct i2c_board_info *info)
1184 {
1185 	struct i2c_adapter *adapter = client->adapter;
1186 	int address = client->addr;
1187 	const char *name = NULL;
1188 	int man_id, chip_id, config1, config2, convrate;
1189 
1190 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
1191 		return -ENODEV;
1192 
1193 	/* detection and identification */
1194 	man_id = i2c_smbus_read_byte_data(client, LM90_REG_R_MAN_ID);
1195 	chip_id = i2c_smbus_read_byte_data(client, LM90_REG_R_CHIP_ID);
1196 	config1 = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG1);
1197 	convrate = i2c_smbus_read_byte_data(client, LM90_REG_R_CONVRATE);
1198 	if (man_id < 0 || chip_id < 0 || config1 < 0 || convrate < 0)
1199 		return -ENODEV;
1200 
1201 	if (man_id == 0x01 || man_id == 0x5C || man_id == 0x41) {
1202 		config2 = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG2);
1203 		if (config2 < 0)
1204 			return -ENODEV;
1205 	} else
1206 		config2 = 0;		/* Make compiler happy */
1207 
1208 	if ((address == 0x4C || address == 0x4D)
1209 	 && man_id == 0x01) { /* National Semiconductor */
1210 		if ((config1 & 0x2A) == 0x00
1211 		 && (config2 & 0xF8) == 0x00
1212 		 && convrate <= 0x09) {
1213 			if (address == 0x4C
1214 			 && (chip_id & 0xF0) == 0x20) { /* LM90 */
1215 				name = "lm90";
1216 			} else
1217 			if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
1218 				name = "lm99";
1219 				dev_info(&adapter->dev,
1220 					 "Assuming LM99 chip at 0x%02x\n",
1221 					 address);
1222 				dev_info(&adapter->dev,
1223 					 "If it is an LM89, instantiate it "
1224 					 "with the new_device sysfs "
1225 					 "interface\n");
1226 			} else
1227 			if (address == 0x4C
1228 			 && (chip_id & 0xF0) == 0x10) { /* LM86 */
1229 				name = "lm86";
1230 			}
1231 		}
1232 	} else
1233 	if ((address == 0x4C || address == 0x4D)
1234 	 && man_id == 0x41) { /* Analog Devices */
1235 		if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
1236 		 && (config1 & 0x3F) == 0x00
1237 		 && convrate <= 0x0A) {
1238 			name = "adm1032";
1239 			/*
1240 			 * The ADM1032 supports PEC, but only if combined
1241 			 * transactions are not used.
1242 			 */
1243 			if (i2c_check_functionality(adapter,
1244 						    I2C_FUNC_SMBUS_BYTE))
1245 				info->flags |= I2C_CLIENT_PEC;
1246 		} else
1247 		if (chip_id == 0x51 /* ADT7461 */
1248 		 && (config1 & 0x1B) == 0x00
1249 		 && convrate <= 0x0A) {
1250 			name = "adt7461";
1251 		} else
1252 		if (chip_id == 0x57 /* ADT7461A, NCT1008 */
1253 		 && (config1 & 0x1B) == 0x00
1254 		 && convrate <= 0x0A) {
1255 			name = "adt7461a";
1256 		}
1257 	} else
1258 	if (man_id == 0x4D) { /* Maxim */
1259 		int emerg, emerg2, status2;
1260 
1261 		/*
1262 		 * We read MAX6659_REG_R_REMOTE_EMERG twice, and re-read
1263 		 * LM90_REG_R_MAN_ID in between. If MAX6659_REG_R_REMOTE_EMERG
1264 		 * exists, both readings will reflect the same value. Otherwise,
1265 		 * the readings will be different.
1266 		 */
1267 		emerg = i2c_smbus_read_byte_data(client,
1268 						 MAX6659_REG_R_REMOTE_EMERG);
1269 		man_id = i2c_smbus_read_byte_data(client,
1270 						  LM90_REG_R_MAN_ID);
1271 		emerg2 = i2c_smbus_read_byte_data(client,
1272 						  MAX6659_REG_R_REMOTE_EMERG);
1273 		status2 = i2c_smbus_read_byte_data(client,
1274 						   MAX6696_REG_R_STATUS2);
1275 		if (emerg < 0 || man_id < 0 || emerg2 < 0 || status2 < 0)
1276 			return -ENODEV;
1277 
1278 		/*
1279 		 * The MAX6657, MAX6658 and MAX6659 do NOT have a chip_id
1280 		 * register. Reading from that address will return the last
1281 		 * read value, which in our case is those of the man_id
1282 		 * register. Likewise, the config1 register seems to lack a
1283 		 * low nibble, so the value will be those of the previous
1284 		 * read, so in our case those of the man_id register.
1285 		 * MAX6659 has a third set of upper temperature limit registers.
1286 		 * Those registers also return values on MAX6657 and MAX6658,
1287 		 * thus the only way to detect MAX6659 is by its address.
1288 		 * For this reason it will be mis-detected as MAX6657 if its
1289 		 * address is 0x4C.
1290 		 */
1291 		if (chip_id == man_id
1292 		 && (address == 0x4C || address == 0x4D || address == 0x4E)
1293 		 && (config1 & 0x1F) == (man_id & 0x0F)
1294 		 && convrate <= 0x09) {
1295 			if (address == 0x4C)
1296 				name = "max6657";
1297 			else
1298 				name = "max6659";
1299 		} else
1300 		/*
1301 		 * Even though MAX6695 and MAX6696 do not have a chip ID
1302 		 * register, reading it returns 0x01. Bit 4 of the config1
1303 		 * register is unused and should return zero when read. Bit 0 of
1304 		 * the status2 register is unused and should return zero when
1305 		 * read.
1306 		 *
1307 		 * MAX6695 and MAX6696 have an additional set of temperature
1308 		 * limit registers. We can detect those chips by checking if
1309 		 * one of those registers exists.
1310 		 */
1311 		if (chip_id == 0x01
1312 		 && (config1 & 0x10) == 0x00
1313 		 && (status2 & 0x01) == 0x00
1314 		 && emerg == emerg2
1315 		 && convrate <= 0x07) {
1316 			name = "max6696";
1317 		} else
1318 		/*
1319 		 * The chip_id register of the MAX6680 and MAX6681 holds the
1320 		 * revision of the chip. The lowest bit of the config1 register
1321 		 * is unused and should return zero when read, so should the
1322 		 * second to last bit of config1 (software reset).
1323 		 */
1324 		if (chip_id == 0x01
1325 		 && (config1 & 0x03) == 0x00
1326 		 && convrate <= 0x07) {
1327 			name = "max6680";
1328 		} else
1329 		/*
1330 		 * The chip_id register of the MAX6646/6647/6649 holds the
1331 		 * revision of the chip. The lowest 6 bits of the config1
1332 		 * register are unused and should return zero when read.
1333 		 */
1334 		if (chip_id == 0x59
1335 		 && (config1 & 0x3f) == 0x00
1336 		 && convrate <= 0x07) {
1337 			name = "max6646";
1338 		}
1339 	} else
1340 	if (address == 0x4C
1341 	 && man_id == 0x5C) { /* Winbond/Nuvoton */
1342 		if ((config1 & 0x2A) == 0x00
1343 		 && (config2 & 0xF8) == 0x00) {
1344 			if (chip_id == 0x01 /* W83L771W/G */
1345 			 && convrate <= 0x09) {
1346 				name = "w83l771";
1347 			} else
1348 			if ((chip_id & 0xFE) == 0x10 /* W83L771AWG/ASG */
1349 			 && convrate <= 0x08) {
1350 				name = "w83l771";
1351 			}
1352 		}
1353 	} else
1354 	if (address >= 0x48 && address <= 0x4F
1355 	 && man_id == 0xA1) { /*  NXP Semiconductor/Philips */
1356 		if (chip_id == 0x00
1357 		 && (config1 & 0x2A) == 0x00
1358 		 && (config2 & 0xFE) == 0x00
1359 		 && convrate <= 0x09) {
1360 			name = "sa56004";
1361 		}
1362 	} else
1363 	if ((address == 0x4C || address == 0x4D)
1364 	 && man_id == 0x47) { /* GMT */
1365 		if (chip_id == 0x01 /* G781 */
1366 		 && (config1 & 0x3F) == 0x00
1367 		 && convrate <= 0x08)
1368 			name = "g781";
1369 	} else
1370 	if (address == 0x4C
1371 	 && man_id == 0x55) { /* Texas Instruments */
1372 		int local_ext;
1373 
1374 		local_ext = i2c_smbus_read_byte_data(client,
1375 						     TMP451_REG_R_LOCAL_TEMPL);
1376 
1377 		if (chip_id == 0x00 /* TMP451 */
1378 		 && (config1 & 0x1B) == 0x00
1379 		 && convrate <= 0x09
1380 		 && (local_ext & 0x0F) == 0x00)
1381 			name = "tmp451";
1382 	}
1383 
1384 	if (!name) { /* identification failed */
1385 		dev_dbg(&adapter->dev,
1386 			"Unsupported chip at 0x%02x (man_id=0x%02X, "
1387 			"chip_id=0x%02X)\n", address, man_id, chip_id);
1388 		return -ENODEV;
1389 	}
1390 
1391 	strlcpy(info->type, name, I2C_NAME_SIZE);
1392 
1393 	return 0;
1394 }
1395 
1396 static void lm90_remove_files(struct i2c_client *client, struct lm90_data *data)
1397 {
1398 	struct device *dev = &client->dev;
1399 
1400 	if (data->flags & LM90_HAVE_TEMP3)
1401 		sysfs_remove_group(&dev->kobj, &lm90_temp3_group);
1402 	if (data->flags & LM90_HAVE_EMERGENCY_ALARM)
1403 		sysfs_remove_group(&dev->kobj, &lm90_emergency_alarm_group);
1404 	if (data->flags & LM90_HAVE_EMERGENCY)
1405 		sysfs_remove_group(&dev->kobj, &lm90_emergency_group);
1406 	if (data->flags & LM90_HAVE_OFFSET)
1407 		device_remove_file(dev, &sensor_dev_attr_temp2_offset.dev_attr);
1408 	device_remove_file(dev, &dev_attr_pec);
1409 	sysfs_remove_group(&dev->kobj, &lm90_group);
1410 }
1411 
1412 static void lm90_restore_conf(struct i2c_client *client, struct lm90_data *data)
1413 {
1414 	/* Restore initial configuration */
1415 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
1416 				  data->convrate_orig);
1417 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
1418 				  data->config_orig);
1419 }
1420 
1421 static void lm90_init_client(struct i2c_client *client)
1422 {
1423 	u8 config, convrate;
1424 	struct lm90_data *data = i2c_get_clientdata(client);
1425 
1426 	if (lm90_read_reg(client, LM90_REG_R_CONVRATE, &convrate) < 0) {
1427 		dev_warn(&client->dev, "Failed to read convrate register!\n");
1428 		convrate = LM90_DEF_CONVRATE_RVAL;
1429 	}
1430 	data->convrate_orig = convrate;
1431 
1432 	/*
1433 	 * Start the conversions.
1434 	 */
1435 	lm90_set_convrate(client, data, 500);	/* 500ms; 2Hz conversion rate */
1436 	if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) {
1437 		dev_warn(&client->dev, "Initialization failed!\n");
1438 		return;
1439 	}
1440 	data->config_orig = config;
1441 
1442 	/* Check Temperature Range Select */
1443 	if (data->kind == adt7461 || data->kind == tmp451) {
1444 		if (config & 0x04)
1445 			data->flags |= LM90_FLAG_ADT7461_EXT;
1446 	}
1447 
1448 	/*
1449 	 * Put MAX6680/MAX8881 into extended resolution (bit 0x10,
1450 	 * 0.125 degree resolution) and range (0x08, extend range
1451 	 * to -64 degree) mode for the remote temperature sensor.
1452 	 */
1453 	if (data->kind == max6680)
1454 		config |= 0x18;
1455 
1456 	/*
1457 	 * Select external channel 0 for max6695/96
1458 	 */
1459 	if (data->kind == max6696)
1460 		config &= ~0x08;
1461 
1462 	config &= 0xBF;	/* run */
1463 	if (config != data->config_orig) /* Only write if changed */
1464 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config);
1465 }
1466 
1467 static bool lm90_is_tripped(struct i2c_client *client, u16 *status)
1468 {
1469 	struct lm90_data *data = i2c_get_clientdata(client);
1470 	u8 st, st2 = 0;
1471 
1472 	lm90_read_reg(client, LM90_REG_R_STATUS, &st);
1473 
1474 	if (data->kind == max6696)
1475 		lm90_read_reg(client, MAX6696_REG_R_STATUS2, &st2);
1476 
1477 	*status = st | (st2 << 8);
1478 
1479 	if ((st & 0x7f) == 0 && (st2 & 0xfe) == 0)
1480 		return false;
1481 
1482 	if ((st & (LM90_STATUS_LLOW | LM90_STATUS_LHIGH | LM90_STATUS_LTHRM)) ||
1483 	    (st2 & MAX6696_STATUS2_LOT2))
1484 		dev_warn(&client->dev,
1485 			 "temp%d out of range, please check!\n", 1);
1486 	if ((st & (LM90_STATUS_RLOW | LM90_STATUS_RHIGH | LM90_STATUS_RTHRM)) ||
1487 	    (st2 & MAX6696_STATUS2_ROT2))
1488 		dev_warn(&client->dev,
1489 			 "temp%d out of range, please check!\n", 2);
1490 	if (st & LM90_STATUS_ROPEN)
1491 		dev_warn(&client->dev,
1492 			 "temp%d diode open, please check!\n", 2);
1493 	if (st2 & (MAX6696_STATUS2_R2LOW | MAX6696_STATUS2_R2HIGH |
1494 		   MAX6696_STATUS2_R2THRM | MAX6696_STATUS2_R2OT2))
1495 		dev_warn(&client->dev,
1496 			 "temp%d out of range, please check!\n", 3);
1497 	if (st2 & MAX6696_STATUS2_R2OPEN)
1498 		dev_warn(&client->dev,
1499 			 "temp%d diode open, please check!\n", 3);
1500 
1501 	return true;
1502 }
1503 
1504 static irqreturn_t lm90_irq_thread(int irq, void *dev_id)
1505 {
1506 	struct i2c_client *client = dev_id;
1507 	u16 status;
1508 
1509 	if (lm90_is_tripped(client, &status))
1510 		return IRQ_HANDLED;
1511 	else
1512 		return IRQ_NONE;
1513 }
1514 
1515 static int lm90_probe(struct i2c_client *client,
1516 		      const struct i2c_device_id *id)
1517 {
1518 	struct device *dev = &client->dev;
1519 	struct i2c_adapter *adapter = to_i2c_adapter(dev->parent);
1520 	struct lm90_data *data;
1521 	struct regulator *regulator;
1522 	int err;
1523 
1524 	regulator = devm_regulator_get(dev, "vcc");
1525 	if (IS_ERR(regulator))
1526 		return PTR_ERR(regulator);
1527 
1528 	err = regulator_enable(regulator);
1529 	if (err < 0) {
1530 		dev_err(&client->dev,
1531 			"Failed to enable regulator: %d\n", err);
1532 		return err;
1533 	}
1534 
1535 	data = devm_kzalloc(&client->dev, sizeof(struct lm90_data), GFP_KERNEL);
1536 	if (!data)
1537 		return -ENOMEM;
1538 
1539 	i2c_set_clientdata(client, data);
1540 	mutex_init(&data->update_lock);
1541 
1542 	data->regulator = regulator;
1543 
1544 	/* Set the device type */
1545 	data->kind = id->driver_data;
1546 	if (data->kind == adm1032) {
1547 		if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
1548 			client->flags &= ~I2C_CLIENT_PEC;
1549 	}
1550 
1551 	/*
1552 	 * Different devices have different alarm bits triggering the
1553 	 * ALERT# output
1554 	 */
1555 	data->alert_alarms = lm90_params[data->kind].alert_alarms;
1556 
1557 	/* Set chip capabilities */
1558 	data->flags = lm90_params[data->kind].flags;
1559 	data->reg_local_ext = lm90_params[data->kind].reg_local_ext;
1560 
1561 	/* Set maximum conversion rate */
1562 	data->max_convrate = lm90_params[data->kind].max_convrate;
1563 
1564 	/* Initialize the LM90 chip */
1565 	lm90_init_client(client);
1566 
1567 	/* Register sysfs hooks */
1568 	err = sysfs_create_group(&dev->kobj, &lm90_group);
1569 	if (err)
1570 		goto exit_restore;
1571 	if (client->flags & I2C_CLIENT_PEC) {
1572 		err = device_create_file(dev, &dev_attr_pec);
1573 		if (err)
1574 			goto exit_remove_files;
1575 	}
1576 	if (data->flags & LM90_HAVE_OFFSET) {
1577 		err = device_create_file(dev,
1578 					&sensor_dev_attr_temp2_offset.dev_attr);
1579 		if (err)
1580 			goto exit_remove_files;
1581 	}
1582 	if (data->flags & LM90_HAVE_EMERGENCY) {
1583 		err = sysfs_create_group(&dev->kobj, &lm90_emergency_group);
1584 		if (err)
1585 			goto exit_remove_files;
1586 	}
1587 	if (data->flags & LM90_HAVE_EMERGENCY_ALARM) {
1588 		err = sysfs_create_group(&dev->kobj,
1589 					 &lm90_emergency_alarm_group);
1590 		if (err)
1591 			goto exit_remove_files;
1592 	}
1593 	if (data->flags & LM90_HAVE_TEMP3) {
1594 		err = sysfs_create_group(&dev->kobj, &lm90_temp3_group);
1595 		if (err)
1596 			goto exit_remove_files;
1597 	}
1598 
1599 	data->hwmon_dev = hwmon_device_register(dev);
1600 	if (IS_ERR(data->hwmon_dev)) {
1601 		err = PTR_ERR(data->hwmon_dev);
1602 		goto exit_remove_files;
1603 	}
1604 
1605 	if (client->irq) {
1606 		dev_dbg(dev, "IRQ: %d\n", client->irq);
1607 		err = devm_request_threaded_irq(dev, client->irq,
1608 						NULL, lm90_irq_thread,
1609 						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
1610 						"lm90", client);
1611 		if (err < 0) {
1612 			dev_err(dev, "cannot request IRQ %d\n", client->irq);
1613 			goto exit_unregister;
1614 		}
1615 	}
1616 
1617 	return 0;
1618 
1619 exit_unregister:
1620 	hwmon_device_unregister(data->hwmon_dev);
1621 exit_remove_files:
1622 	lm90_remove_files(client, data);
1623 exit_restore:
1624 	lm90_restore_conf(client, data);
1625 	regulator_disable(data->regulator);
1626 
1627 	return err;
1628 }
1629 
1630 static int lm90_remove(struct i2c_client *client)
1631 {
1632 	struct lm90_data *data = i2c_get_clientdata(client);
1633 
1634 	hwmon_device_unregister(data->hwmon_dev);
1635 	lm90_remove_files(client, data);
1636 	lm90_restore_conf(client, data);
1637 	regulator_disable(data->regulator);
1638 
1639 	return 0;
1640 }
1641 
1642 static void lm90_alert(struct i2c_client *client, unsigned int flag)
1643 {
1644 	u16 alarms;
1645 
1646 	if (lm90_is_tripped(client, &alarms)) {
1647 		/*
1648 		 * Disable ALERT# output, because these chips don't implement
1649 		 * SMBus alert correctly; they should only hold the alert line
1650 		 * low briefly.
1651 		 */
1652 		struct lm90_data *data = i2c_get_clientdata(client);
1653 
1654 		if ((data->flags & LM90_HAVE_BROKEN_ALERT)
1655 		 && (alarms & data->alert_alarms)) {
1656 			u8 config;
1657 			dev_dbg(&client->dev, "Disabling ALERT#\n");
1658 			lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
1659 			i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
1660 						  config | 0x80);
1661 		}
1662 	} else {
1663 		dev_info(&client->dev, "Everything OK\n");
1664 	}
1665 }
1666 
1667 static struct i2c_driver lm90_driver = {
1668 	.class		= I2C_CLASS_HWMON,
1669 	.driver = {
1670 		.name	= "lm90",
1671 	},
1672 	.probe		= lm90_probe,
1673 	.remove		= lm90_remove,
1674 	.alert		= lm90_alert,
1675 	.id_table	= lm90_id,
1676 	.detect		= lm90_detect,
1677 	.address_list	= normal_i2c,
1678 };
1679 
1680 module_i2c_driver(lm90_driver);
1681 
1682 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
1683 MODULE_DESCRIPTION("LM90/ADM1032 driver");
1684 MODULE_LICENSE("GPL");
1685