xref: /linux/drivers/hwmon/lm90.c (revision 63307d015b91e626c97bb82e88054af3d0b74643)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
4  *          monitoring
5  * Copyright (C) 2003-2010  Jean Delvare <jdelvare@suse.de>
6  *
7  * Based on the lm83 driver. The LM90 is a sensor chip made by National
8  * Semiconductor. It reports up to two temperatures (its own plus up to
9  * one external one) with a 0.125 deg resolution (1 deg for local
10  * temperature) and a 3-4 deg accuracy.
11  *
12  * This driver also supports the LM89 and LM99, two other sensor chips
13  * made by National Semiconductor. Both have an increased remote
14  * temperature measurement accuracy (1 degree), and the LM99
15  * additionally shifts remote temperatures (measured and limits) by 16
16  * degrees, which allows for higher temperatures measurement.
17  * Note that there is no way to differentiate between both chips.
18  * When device is auto-detected, the driver will assume an LM99.
19  *
20  * This driver also supports the LM86, another sensor chip made by
21  * National Semiconductor. It is exactly similar to the LM90 except it
22  * has a higher accuracy.
23  *
24  * This driver also supports the ADM1032, a sensor chip made by Analog
25  * Devices. That chip is similar to the LM90, with a few differences
26  * that are not handled by this driver. Among others, it has a higher
27  * accuracy than the LM90, much like the LM86 does.
28  *
29  * This driver also supports the MAX6657, MAX6658 and MAX6659 sensor
30  * chips made by Maxim. These chips are similar to the LM86.
31  * Note that there is no easy way to differentiate between the three
32  * variants. We use the device address to detect MAX6659, which will result
33  * in a detection as max6657 if it is on address 0x4c. The extra address
34  * and features of the MAX6659 are only supported if the chip is configured
35  * explicitly as max6659, or if its address is not 0x4c.
36  * These chips lack the remote temperature offset feature.
37  *
38  * This driver also supports the MAX6646, MAX6647, MAX6648, MAX6649 and
39  * MAX6692 chips made by Maxim.  These are again similar to the LM86,
40  * but they use unsigned temperature values and can report temperatures
41  * from 0 to 145 degrees.
42  *
43  * This driver also supports the MAX6680 and MAX6681, two other sensor
44  * chips made by Maxim. These are quite similar to the other Maxim
45  * chips. The MAX6680 and MAX6681 only differ in the pinout so they can
46  * be treated identically.
47  *
48  * This driver also supports the MAX6695 and MAX6696, two other sensor
49  * chips made by Maxim. These are also quite similar to other Maxim
50  * chips, but support three temperature sensors instead of two. MAX6695
51  * and MAX6696 only differ in the pinout so they can be treated identically.
52  *
53  * This driver also supports ADT7461 and ADT7461A from Analog Devices as well as
54  * NCT1008 from ON Semiconductor. The chips are supported in both compatibility
55  * and extended mode. They are mostly compatible with LM90 except for a data
56  * format difference for the temperature value registers.
57  *
58  * This driver also supports the SA56004 from Philips. This device is
59  * pin-compatible with the LM86, the ED/EDP parts are also address-compatible.
60  *
61  * This driver also supports the G781 from GMT. This device is compatible
62  * with the ADM1032.
63  *
64  * This driver also supports TMP451 from Texas Instruments. This device is
65  * supported in both compatibility and extended mode. It's mostly compatible
66  * with ADT7461 except for local temperature low byte register and max
67  * conversion rate.
68  *
69  * Since the LM90 was the first chipset supported by this driver, most
70  * comments will refer to this chipset, but are actually general and
71  * concern all supported chipsets, unless mentioned otherwise.
72  */
73 
74 #include <linux/module.h>
75 #include <linux/init.h>
76 #include <linux/slab.h>
77 #include <linux/jiffies.h>
78 #include <linux/i2c.h>
79 #include <linux/hwmon.h>
80 #include <linux/err.h>
81 #include <linux/mutex.h>
82 #include <linux/of_device.h>
83 #include <linux/sysfs.h>
84 #include <linux/interrupt.h>
85 #include <linux/regulator/consumer.h>
86 
87 /*
88  * Addresses to scan
89  * Address is fully defined internally and cannot be changed except for
90  * MAX6659, MAX6680 and MAX6681.
91  * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, ADT7461A, MAX6649,
92  * MAX6657, MAX6658, NCT1008 and W83L771 have address 0x4c.
93  * ADM1032-2, ADT7461-2, ADT7461A-2, LM89-1, LM99-1, MAX6646, and NCT1008D
94  * have address 0x4d.
95  * MAX6647 has address 0x4e.
96  * MAX6659 can have address 0x4c, 0x4d or 0x4e.
97  * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
98  * 0x4c, 0x4d or 0x4e.
99  * SA56004 can have address 0x48 through 0x4F.
100  */
101 
102 static const unsigned short normal_i2c[] = {
103 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x48, 0x49, 0x4a, 0x4b, 0x4c,
104 	0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
105 
106 enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
107 	max6646, w83l771, max6696, sa56004, g781, tmp451 };
108 
109 /*
110  * The LM90 registers
111  */
112 
113 #define LM90_REG_R_MAN_ID		0xFE
114 #define LM90_REG_R_CHIP_ID		0xFF
115 #define LM90_REG_R_CONFIG1		0x03
116 #define LM90_REG_W_CONFIG1		0x09
117 #define LM90_REG_R_CONFIG2		0xBF
118 #define LM90_REG_W_CONFIG2		0xBF
119 #define LM90_REG_R_CONVRATE		0x04
120 #define LM90_REG_W_CONVRATE		0x0A
121 #define LM90_REG_R_STATUS		0x02
122 #define LM90_REG_R_LOCAL_TEMP		0x00
123 #define LM90_REG_R_LOCAL_HIGH		0x05
124 #define LM90_REG_W_LOCAL_HIGH		0x0B
125 #define LM90_REG_R_LOCAL_LOW		0x06
126 #define LM90_REG_W_LOCAL_LOW		0x0C
127 #define LM90_REG_R_LOCAL_CRIT		0x20
128 #define LM90_REG_W_LOCAL_CRIT		0x20
129 #define LM90_REG_R_REMOTE_TEMPH		0x01
130 #define LM90_REG_R_REMOTE_TEMPL		0x10
131 #define LM90_REG_R_REMOTE_OFFSH		0x11
132 #define LM90_REG_W_REMOTE_OFFSH		0x11
133 #define LM90_REG_R_REMOTE_OFFSL		0x12
134 #define LM90_REG_W_REMOTE_OFFSL		0x12
135 #define LM90_REG_R_REMOTE_HIGHH		0x07
136 #define LM90_REG_W_REMOTE_HIGHH		0x0D
137 #define LM90_REG_R_REMOTE_HIGHL		0x13
138 #define LM90_REG_W_REMOTE_HIGHL		0x13
139 #define LM90_REG_R_REMOTE_LOWH		0x08
140 #define LM90_REG_W_REMOTE_LOWH		0x0E
141 #define LM90_REG_R_REMOTE_LOWL		0x14
142 #define LM90_REG_W_REMOTE_LOWL		0x14
143 #define LM90_REG_R_REMOTE_CRIT		0x19
144 #define LM90_REG_W_REMOTE_CRIT		0x19
145 #define LM90_REG_R_TCRIT_HYST		0x21
146 #define LM90_REG_W_TCRIT_HYST		0x21
147 
148 /* MAX6646/6647/6649/6657/6658/6659/6695/6696 registers */
149 
150 #define MAX6657_REG_R_LOCAL_TEMPL	0x11
151 #define MAX6696_REG_R_STATUS2		0x12
152 #define MAX6659_REG_R_REMOTE_EMERG	0x16
153 #define MAX6659_REG_W_REMOTE_EMERG	0x16
154 #define MAX6659_REG_R_LOCAL_EMERG	0x17
155 #define MAX6659_REG_W_LOCAL_EMERG	0x17
156 
157 /*  SA56004 registers */
158 
159 #define SA56004_REG_R_LOCAL_TEMPL 0x22
160 
161 #define LM90_MAX_CONVRATE_MS	16000	/* Maximum conversion rate in ms */
162 
163 /* TMP451 registers */
164 #define TMP451_REG_R_LOCAL_TEMPL	0x15
165 
166 /*
167  * Device flags
168  */
169 #define LM90_FLAG_ADT7461_EXT	(1 << 0) /* ADT7461 extended mode	*/
170 /* Device features */
171 #define LM90_HAVE_OFFSET	(1 << 1) /* temperature offset register	*/
172 #define LM90_HAVE_REM_LIMIT_EXT	(1 << 3) /* extended remote limit	*/
173 #define LM90_HAVE_EMERGENCY	(1 << 4) /* 3rd upper (emergency) limit	*/
174 #define LM90_HAVE_EMERGENCY_ALARM (1 << 5)/* emergency alarm		*/
175 #define LM90_HAVE_TEMP3		(1 << 6) /* 3rd temperature sensor	*/
176 #define LM90_HAVE_BROKEN_ALERT	(1 << 7) /* Broken alert		*/
177 
178 /* LM90 status */
179 #define LM90_STATUS_LTHRM	(1 << 0) /* local THERM limit tripped */
180 #define LM90_STATUS_RTHRM	(1 << 1) /* remote THERM limit tripped */
181 #define LM90_STATUS_ROPEN	(1 << 2) /* remote is an open circuit */
182 #define LM90_STATUS_RLOW	(1 << 3) /* remote low temp limit tripped */
183 #define LM90_STATUS_RHIGH	(1 << 4) /* remote high temp limit tripped */
184 #define LM90_STATUS_LLOW	(1 << 5) /* local low temp limit tripped */
185 #define LM90_STATUS_LHIGH	(1 << 6) /* local high temp limit tripped */
186 
187 #define MAX6696_STATUS2_R2THRM	(1 << 1) /* remote2 THERM limit tripped */
188 #define MAX6696_STATUS2_R2OPEN	(1 << 2) /* remote2 is an open circuit */
189 #define MAX6696_STATUS2_R2LOW	(1 << 3) /* remote2 low temp limit tripped */
190 #define MAX6696_STATUS2_R2HIGH	(1 << 4) /* remote2 high temp limit tripped */
191 #define MAX6696_STATUS2_ROT2	(1 << 5) /* remote emergency limit tripped */
192 #define MAX6696_STATUS2_R2OT2	(1 << 6) /* remote2 emergency limit tripped */
193 #define MAX6696_STATUS2_LOT2	(1 << 7) /* local emergency limit tripped */
194 
195 /*
196  * Driver data (common to all clients)
197  */
198 
199 static const struct i2c_device_id lm90_id[] = {
200 	{ "adm1032", adm1032 },
201 	{ "adt7461", adt7461 },
202 	{ "adt7461a", adt7461 },
203 	{ "g781", g781 },
204 	{ "lm90", lm90 },
205 	{ "lm86", lm86 },
206 	{ "lm89", lm86 },
207 	{ "lm99", lm99 },
208 	{ "max6646", max6646 },
209 	{ "max6647", max6646 },
210 	{ "max6649", max6646 },
211 	{ "max6657", max6657 },
212 	{ "max6658", max6657 },
213 	{ "max6659", max6659 },
214 	{ "max6680", max6680 },
215 	{ "max6681", max6680 },
216 	{ "max6695", max6696 },
217 	{ "max6696", max6696 },
218 	{ "nct1008", adt7461 },
219 	{ "w83l771", w83l771 },
220 	{ "sa56004", sa56004 },
221 	{ "tmp451", tmp451 },
222 	{ }
223 };
224 MODULE_DEVICE_TABLE(i2c, lm90_id);
225 
226 static const struct of_device_id __maybe_unused lm90_of_match[] = {
227 	{
228 		.compatible = "adi,adm1032",
229 		.data = (void *)adm1032
230 	},
231 	{
232 		.compatible = "adi,adt7461",
233 		.data = (void *)adt7461
234 	},
235 	{
236 		.compatible = "adi,adt7461a",
237 		.data = (void *)adt7461
238 	},
239 	{
240 		.compatible = "gmt,g781",
241 		.data = (void *)g781
242 	},
243 	{
244 		.compatible = "national,lm90",
245 		.data = (void *)lm90
246 	},
247 	{
248 		.compatible = "national,lm86",
249 		.data = (void *)lm86
250 	},
251 	{
252 		.compatible = "national,lm89",
253 		.data = (void *)lm86
254 	},
255 	{
256 		.compatible = "national,lm99",
257 		.data = (void *)lm99
258 	},
259 	{
260 		.compatible = "dallas,max6646",
261 		.data = (void *)max6646
262 	},
263 	{
264 		.compatible = "dallas,max6647",
265 		.data = (void *)max6646
266 	},
267 	{
268 		.compatible = "dallas,max6649",
269 		.data = (void *)max6646
270 	},
271 	{
272 		.compatible = "dallas,max6657",
273 		.data = (void *)max6657
274 	},
275 	{
276 		.compatible = "dallas,max6658",
277 		.data = (void *)max6657
278 	},
279 	{
280 		.compatible = "dallas,max6659",
281 		.data = (void *)max6659
282 	},
283 	{
284 		.compatible = "dallas,max6680",
285 		.data = (void *)max6680
286 	},
287 	{
288 		.compatible = "dallas,max6681",
289 		.data = (void *)max6680
290 	},
291 	{
292 		.compatible = "dallas,max6695",
293 		.data = (void *)max6696
294 	},
295 	{
296 		.compatible = "dallas,max6696",
297 		.data = (void *)max6696
298 	},
299 	{
300 		.compatible = "onnn,nct1008",
301 		.data = (void *)adt7461
302 	},
303 	{
304 		.compatible = "winbond,w83l771",
305 		.data = (void *)w83l771
306 	},
307 	{
308 		.compatible = "nxp,sa56004",
309 		.data = (void *)sa56004
310 	},
311 	{
312 		.compatible = "ti,tmp451",
313 		.data = (void *)tmp451
314 	},
315 	{ },
316 };
317 MODULE_DEVICE_TABLE(of, lm90_of_match);
318 
319 /*
320  * chip type specific parameters
321  */
322 struct lm90_params {
323 	u32 flags;		/* Capabilities */
324 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
325 				/* Upper 8 bits for max6695/96 */
326 	u8 max_convrate;	/* Maximum conversion rate register value */
327 	u8 reg_local_ext;	/* Extended local temp register (optional) */
328 };
329 
330 static const struct lm90_params lm90_params[] = {
331 	[adm1032] = {
332 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
333 		  | LM90_HAVE_BROKEN_ALERT,
334 		.alert_alarms = 0x7c,
335 		.max_convrate = 10,
336 	},
337 	[adt7461] = {
338 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
339 		  | LM90_HAVE_BROKEN_ALERT,
340 		.alert_alarms = 0x7c,
341 		.max_convrate = 10,
342 	},
343 	[g781] = {
344 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
345 		  | LM90_HAVE_BROKEN_ALERT,
346 		.alert_alarms = 0x7c,
347 		.max_convrate = 8,
348 	},
349 	[lm86] = {
350 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
351 		.alert_alarms = 0x7b,
352 		.max_convrate = 9,
353 	},
354 	[lm90] = {
355 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
356 		.alert_alarms = 0x7b,
357 		.max_convrate = 9,
358 	},
359 	[lm99] = {
360 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
361 		.alert_alarms = 0x7b,
362 		.max_convrate = 9,
363 	},
364 	[max6646] = {
365 		.alert_alarms = 0x7c,
366 		.max_convrate = 6,
367 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
368 	},
369 	[max6657] = {
370 		.alert_alarms = 0x7c,
371 		.max_convrate = 8,
372 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
373 	},
374 	[max6659] = {
375 		.flags = LM90_HAVE_EMERGENCY,
376 		.alert_alarms = 0x7c,
377 		.max_convrate = 8,
378 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
379 	},
380 	[max6680] = {
381 		.flags = LM90_HAVE_OFFSET,
382 		.alert_alarms = 0x7c,
383 		.max_convrate = 7,
384 	},
385 	[max6696] = {
386 		.flags = LM90_HAVE_EMERGENCY
387 		  | LM90_HAVE_EMERGENCY_ALARM | LM90_HAVE_TEMP3,
388 		.alert_alarms = 0x1c7c,
389 		.max_convrate = 6,
390 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
391 	},
392 	[w83l771] = {
393 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
394 		.alert_alarms = 0x7c,
395 		.max_convrate = 8,
396 	},
397 	[sa56004] = {
398 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
399 		.alert_alarms = 0x7b,
400 		.max_convrate = 9,
401 		.reg_local_ext = SA56004_REG_R_LOCAL_TEMPL,
402 	},
403 	[tmp451] = {
404 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
405 		  | LM90_HAVE_BROKEN_ALERT,
406 		.alert_alarms = 0x7c,
407 		.max_convrate = 9,
408 		.reg_local_ext = TMP451_REG_R_LOCAL_TEMPL,
409 	},
410 };
411 
412 /*
413  * TEMP8 register index
414  */
415 enum lm90_temp8_reg_index {
416 	LOCAL_LOW = 0,
417 	LOCAL_HIGH,
418 	LOCAL_CRIT,
419 	REMOTE_CRIT,
420 	LOCAL_EMERG,	/* max6659 and max6695/96 */
421 	REMOTE_EMERG,	/* max6659 and max6695/96 */
422 	REMOTE2_CRIT,	/* max6695/96 only */
423 	REMOTE2_EMERG,	/* max6695/96 only */
424 	TEMP8_REG_NUM
425 };
426 
427 /*
428  * TEMP11 register index
429  */
430 enum lm90_temp11_reg_index {
431 	REMOTE_TEMP = 0,
432 	REMOTE_LOW,
433 	REMOTE_HIGH,
434 	REMOTE_OFFSET,	/* except max6646, max6657/58/59, and max6695/96 */
435 	LOCAL_TEMP,
436 	REMOTE2_TEMP,	/* max6695/96 only */
437 	REMOTE2_LOW,	/* max6695/96 only */
438 	REMOTE2_HIGH,	/* max6695/96 only */
439 	TEMP11_REG_NUM
440 };
441 
442 /*
443  * Client data (each client gets its own)
444  */
445 
446 struct lm90_data {
447 	struct i2c_client *client;
448 	u32 channel_config[4];
449 	struct hwmon_channel_info temp_info;
450 	const struct hwmon_channel_info *info[3];
451 	struct hwmon_chip_info chip;
452 	struct mutex update_lock;
453 	bool valid;		/* true if register values are valid */
454 	unsigned long last_updated; /* in jiffies */
455 	int kind;
456 	u32 flags;
457 
458 	unsigned int update_interval; /* in milliseconds */
459 
460 	u8 config_orig;		/* Original configuration register value */
461 	u8 convrate_orig;	/* Original conversion rate register value */
462 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
463 				/* Upper 8 bits for max6695/96 */
464 	u8 max_convrate;	/* Maximum conversion rate */
465 	u8 reg_local_ext;	/* local extension register offset */
466 
467 	/* registers values */
468 	s8 temp8[TEMP8_REG_NUM];
469 	s16 temp11[TEMP11_REG_NUM];
470 	u8 temp_hyst;
471 	u16 alarms; /* bitvector (upper 8 bits for max6695/96) */
472 };
473 
474 /*
475  * Support functions
476  */
477 
478 /*
479  * The ADM1032 supports PEC but not on write byte transactions, so we need
480  * to explicitly ask for a transaction without PEC.
481  */
482 static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value)
483 {
484 	return i2c_smbus_xfer(client->adapter, client->addr,
485 			      client->flags & ~I2C_CLIENT_PEC,
486 			      I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
487 }
488 
489 /*
490  * It is assumed that client->update_lock is held (unless we are in
491  * detection or initialization steps). This matters when PEC is enabled,
492  * because we don't want the address pointer to change between the write
493  * byte and the read byte transactions.
494  */
495 static int lm90_read_reg(struct i2c_client *client, u8 reg)
496 {
497 	int err;
498 
499 	if (client->flags & I2C_CLIENT_PEC) {
500 		err = adm1032_write_byte(client, reg);
501 		if (err >= 0)
502 			err = i2c_smbus_read_byte(client);
503 	} else
504 		err = i2c_smbus_read_byte_data(client, reg);
505 
506 	return err;
507 }
508 
509 static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl)
510 {
511 	int oldh, newh, l;
512 
513 	/*
514 	 * There is a trick here. We have to read two registers to have the
515 	 * sensor temperature, but we have to beware a conversion could occur
516 	 * between the readings. The datasheet says we should either use
517 	 * the one-shot conversion register, which we don't want to do
518 	 * (disables hardware monitoring) or monitor the busy bit, which is
519 	 * impossible (we can't read the values and monitor that bit at the
520 	 * exact same time). So the solution used here is to read the high
521 	 * byte once, then the low byte, then the high byte again. If the new
522 	 * high byte matches the old one, then we have a valid reading. Else
523 	 * we have to read the low byte again, and now we believe we have a
524 	 * correct reading.
525 	 */
526 	oldh = lm90_read_reg(client, regh);
527 	if (oldh < 0)
528 		return oldh;
529 	l = lm90_read_reg(client, regl);
530 	if (l < 0)
531 		return l;
532 	newh = lm90_read_reg(client, regh);
533 	if (newh < 0)
534 		return newh;
535 	if (oldh != newh) {
536 		l = lm90_read_reg(client, regl);
537 		if (l < 0)
538 			return l;
539 	}
540 	return (newh << 8) | l;
541 }
542 
543 /*
544  * client->update_lock must be held when calling this function (unless we are
545  * in detection or initialization steps), and while a remote channel other
546  * than channel 0 is selected. Also, calling code must make sure to re-select
547  * external channel 0 before releasing the lock. This is necessary because
548  * various registers have different meanings as a result of selecting a
549  * non-default remote channel.
550  */
551 static inline int lm90_select_remote_channel(struct i2c_client *client,
552 					     struct lm90_data *data,
553 					     int channel)
554 {
555 	int config;
556 
557 	if (data->kind == max6696) {
558 		config = lm90_read_reg(client, LM90_REG_R_CONFIG1);
559 		if (config < 0)
560 			return config;
561 		config &= ~0x08;
562 		if (channel)
563 			config |= 0x08;
564 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
565 					  config);
566 	}
567 	return 0;
568 }
569 
570 /*
571  * Set conversion rate.
572  * client->update_lock must be held when calling this function (unless we are
573  * in detection or initialization steps).
574  */
575 static int lm90_set_convrate(struct i2c_client *client, struct lm90_data *data,
576 			     unsigned int interval)
577 {
578 	unsigned int update_interval;
579 	int i, err;
580 
581 	/* Shift calculations to avoid rounding errors */
582 	interval <<= 6;
583 
584 	/* find the nearest update rate */
585 	for (i = 0, update_interval = LM90_MAX_CONVRATE_MS << 6;
586 	     i < data->max_convrate; i++, update_interval >>= 1)
587 		if (interval >= update_interval * 3 / 4)
588 			break;
589 
590 	err = i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, i);
591 	data->update_interval = DIV_ROUND_CLOSEST(update_interval, 64);
592 	return err;
593 }
594 
595 static int lm90_update_limits(struct device *dev)
596 {
597 	struct lm90_data *data = dev_get_drvdata(dev);
598 	struct i2c_client *client = data->client;
599 	int val;
600 
601 	val = lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT);
602 	if (val < 0)
603 		return val;
604 	data->temp8[LOCAL_CRIT] = val;
605 
606 	val = lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT);
607 	if (val < 0)
608 		return val;
609 	data->temp8[REMOTE_CRIT] = val;
610 
611 	val = lm90_read_reg(client, LM90_REG_R_TCRIT_HYST);
612 	if (val < 0)
613 		return val;
614 	data->temp_hyst = val;
615 
616 	val = lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH);
617 	if (val < 0)
618 		return val;
619 	data->temp11[REMOTE_LOW] = val << 8;
620 
621 	if (data->flags & LM90_HAVE_REM_LIMIT_EXT) {
622 		val = lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL);
623 		if (val < 0)
624 			return val;
625 		data->temp11[REMOTE_LOW] |= val;
626 	}
627 
628 	val = lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH);
629 	if (val < 0)
630 		return val;
631 	data->temp11[REMOTE_HIGH] = val << 8;
632 
633 	if (data->flags & LM90_HAVE_REM_LIMIT_EXT) {
634 		val = lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL);
635 		if (val < 0)
636 			return val;
637 		data->temp11[REMOTE_HIGH] |= val;
638 	}
639 
640 	if (data->flags & LM90_HAVE_OFFSET) {
641 		val = lm90_read16(client, LM90_REG_R_REMOTE_OFFSH,
642 				  LM90_REG_R_REMOTE_OFFSL);
643 		if (val < 0)
644 			return val;
645 		data->temp11[REMOTE_OFFSET] = val;
646 	}
647 
648 	if (data->flags & LM90_HAVE_EMERGENCY) {
649 		val = lm90_read_reg(client, MAX6659_REG_R_LOCAL_EMERG);
650 		if (val < 0)
651 			return val;
652 		data->temp8[LOCAL_EMERG] = val;
653 
654 		val = lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG);
655 		if (val < 0)
656 			return val;
657 		data->temp8[REMOTE_EMERG] = val;
658 	}
659 
660 	if (data->kind == max6696) {
661 		val = lm90_select_remote_channel(client, data, 1);
662 		if (val < 0)
663 			return val;
664 
665 		val = lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT);
666 		if (val < 0)
667 			return val;
668 		data->temp8[REMOTE2_CRIT] = val;
669 
670 		val = lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG);
671 		if (val < 0)
672 			return val;
673 		data->temp8[REMOTE2_EMERG] = val;
674 
675 		val = lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH);
676 		if (val < 0)
677 			return val;
678 		data->temp11[REMOTE2_LOW] = val << 8;
679 
680 		val = lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH);
681 		if (val < 0)
682 			return val;
683 		data->temp11[REMOTE2_HIGH] = val << 8;
684 
685 		lm90_select_remote_channel(client, data, 0);
686 	}
687 
688 	return 0;
689 }
690 
691 static int lm90_update_device(struct device *dev)
692 {
693 	struct lm90_data *data = dev_get_drvdata(dev);
694 	struct i2c_client *client = data->client;
695 	unsigned long next_update;
696 	int val;
697 
698 	if (!data->valid) {
699 		val = lm90_update_limits(dev);
700 		if (val < 0)
701 			return val;
702 	}
703 
704 	next_update = data->last_updated +
705 		      msecs_to_jiffies(data->update_interval);
706 	if (time_after(jiffies, next_update) || !data->valid) {
707 		dev_dbg(&client->dev, "Updating lm90 data.\n");
708 
709 		data->valid = false;
710 
711 		val = lm90_read_reg(client, LM90_REG_R_LOCAL_LOW);
712 		if (val < 0)
713 			return val;
714 		data->temp8[LOCAL_LOW] = val;
715 
716 		val = lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH);
717 		if (val < 0)
718 			return val;
719 		data->temp8[LOCAL_HIGH] = val;
720 
721 		if (data->reg_local_ext) {
722 			val = lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
723 					  data->reg_local_ext);
724 			if (val < 0)
725 				return val;
726 			data->temp11[LOCAL_TEMP] = val;
727 		} else {
728 			val = lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP);
729 			if (val < 0)
730 				return val;
731 			data->temp11[LOCAL_TEMP] = val << 8;
732 		}
733 		val = lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
734 				  LM90_REG_R_REMOTE_TEMPL);
735 		if (val < 0)
736 			return val;
737 		data->temp11[REMOTE_TEMP] = val;
738 
739 		val = lm90_read_reg(client, LM90_REG_R_STATUS);
740 		if (val < 0)
741 			return val;
742 		data->alarms = val;	/* lower 8 bit of alarms */
743 
744 		if (data->kind == max6696) {
745 			val = lm90_select_remote_channel(client, data, 1);
746 			if (val < 0)
747 				return val;
748 
749 			val = lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
750 					  LM90_REG_R_REMOTE_TEMPL);
751 			if (val < 0) {
752 				lm90_select_remote_channel(client, data, 0);
753 				return val;
754 			}
755 			data->temp11[REMOTE2_TEMP] = val;
756 
757 			lm90_select_remote_channel(client, data, 0);
758 
759 			val = lm90_read_reg(client, MAX6696_REG_R_STATUS2);
760 			if (val < 0)
761 				return val;
762 			data->alarms |= val << 8;
763 		}
764 
765 		/*
766 		 * Re-enable ALERT# output if it was originally enabled and
767 		 * relevant alarms are all clear
768 		 */
769 		if (!(data->config_orig & 0x80) &&
770 		    !(data->alarms & data->alert_alarms)) {
771 			val = lm90_read_reg(client, LM90_REG_R_CONFIG1);
772 			if (val < 0)
773 				return val;
774 
775 			if (val & 0x80) {
776 				dev_dbg(&client->dev, "Re-enabling ALERT#\n");
777 				i2c_smbus_write_byte_data(client,
778 							  LM90_REG_W_CONFIG1,
779 							  val & ~0x80);
780 			}
781 		}
782 
783 		data->last_updated = jiffies;
784 		data->valid = true;
785 	}
786 
787 	return 0;
788 }
789 
790 /*
791  * Conversions
792  * For local temperatures and limits, critical limits and the hysteresis
793  * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
794  * For remote temperatures and limits, it uses signed 11-bit values with
795  * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.  Some
796  * Maxim chips use unsigned values.
797  */
798 
799 static inline int temp_from_s8(s8 val)
800 {
801 	return val * 1000;
802 }
803 
804 static inline int temp_from_u8(u8 val)
805 {
806 	return val * 1000;
807 }
808 
809 static inline int temp_from_s16(s16 val)
810 {
811 	return val / 32 * 125;
812 }
813 
814 static inline int temp_from_u16(u16 val)
815 {
816 	return val / 32 * 125;
817 }
818 
819 static s8 temp_to_s8(long val)
820 {
821 	if (val <= -128000)
822 		return -128;
823 	if (val >= 127000)
824 		return 127;
825 	if (val < 0)
826 		return (val - 500) / 1000;
827 	return (val + 500) / 1000;
828 }
829 
830 static u8 temp_to_u8(long val)
831 {
832 	if (val <= 0)
833 		return 0;
834 	if (val >= 255000)
835 		return 255;
836 	return (val + 500) / 1000;
837 }
838 
839 static s16 temp_to_s16(long val)
840 {
841 	if (val <= -128000)
842 		return 0x8000;
843 	if (val >= 127875)
844 		return 0x7FE0;
845 	if (val < 0)
846 		return (val - 62) / 125 * 32;
847 	return (val + 62) / 125 * 32;
848 }
849 
850 static u8 hyst_to_reg(long val)
851 {
852 	if (val <= 0)
853 		return 0;
854 	if (val >= 30500)
855 		return 31;
856 	return (val + 500) / 1000;
857 }
858 
859 /*
860  * ADT7461 in compatibility mode is almost identical to LM90 except that
861  * attempts to write values that are outside the range 0 < temp < 127 are
862  * treated as the boundary value.
863  *
864  * ADT7461 in "extended mode" operation uses unsigned integers offset by
865  * 64 (e.g., 0 -> -64 degC).  The range is restricted to -64..191 degC.
866  */
867 static inline int temp_from_u8_adt7461(struct lm90_data *data, u8 val)
868 {
869 	if (data->flags & LM90_FLAG_ADT7461_EXT)
870 		return (val - 64) * 1000;
871 	return temp_from_s8(val);
872 }
873 
874 static inline int temp_from_u16_adt7461(struct lm90_data *data, u16 val)
875 {
876 	if (data->flags & LM90_FLAG_ADT7461_EXT)
877 		return (val - 0x4000) / 64 * 250;
878 	return temp_from_s16(val);
879 }
880 
881 static u8 temp_to_u8_adt7461(struct lm90_data *data, long val)
882 {
883 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
884 		if (val <= -64000)
885 			return 0;
886 		if (val >= 191000)
887 			return 0xFF;
888 		return (val + 500 + 64000) / 1000;
889 	}
890 	if (val <= 0)
891 		return 0;
892 	if (val >= 127000)
893 		return 127;
894 	return (val + 500) / 1000;
895 }
896 
897 static u16 temp_to_u16_adt7461(struct lm90_data *data, long val)
898 {
899 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
900 		if (val <= -64000)
901 			return 0;
902 		if (val >= 191750)
903 			return 0xFFC0;
904 		return (val + 64000 + 125) / 250 * 64;
905 	}
906 	if (val <= 0)
907 		return 0;
908 	if (val >= 127750)
909 		return 0x7FC0;
910 	return (val + 125) / 250 * 64;
911 }
912 
913 /* pec used for ADM1032 only */
914 static ssize_t pec_show(struct device *dev, struct device_attribute *dummy,
915 			char *buf)
916 {
917 	struct i2c_client *client = to_i2c_client(dev);
918 
919 	return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
920 }
921 
922 static ssize_t pec_store(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 	long val;
927 	int err;
928 
929 	err = kstrtol(buf, 10, &val);
930 	if (err < 0)
931 		return err;
932 
933 	switch (val) {
934 	case 0:
935 		client->flags &= ~I2C_CLIENT_PEC;
936 		break;
937 	case 1:
938 		client->flags |= I2C_CLIENT_PEC;
939 		break;
940 	default:
941 		return -EINVAL;
942 	}
943 
944 	return count;
945 }
946 
947 static DEVICE_ATTR_RW(pec);
948 
949 static int lm90_get_temp11(struct lm90_data *data, int index)
950 {
951 	s16 temp11 = data->temp11[index];
952 	int temp;
953 
954 	if (data->kind == adt7461 || data->kind == tmp451)
955 		temp = temp_from_u16_adt7461(data, temp11);
956 	else if (data->kind == max6646)
957 		temp = temp_from_u16(temp11);
958 	else
959 		temp = temp_from_s16(temp11);
960 
961 	/* +16 degrees offset for temp2 for the LM99 */
962 	if (data->kind == lm99 && index <= 2)
963 		temp += 16000;
964 
965 	return temp;
966 }
967 
968 static int lm90_set_temp11(struct lm90_data *data, int index, long val)
969 {
970 	static struct reg {
971 		u8 high;
972 		u8 low;
973 	} reg[] = {
974 	[REMOTE_LOW] = { LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL },
975 	[REMOTE_HIGH] = { LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL },
976 	[REMOTE_OFFSET] = { LM90_REG_W_REMOTE_OFFSH, LM90_REG_W_REMOTE_OFFSL },
977 	[REMOTE2_LOW] = { LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL },
978 	[REMOTE2_HIGH] = { LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL }
979 	};
980 	struct i2c_client *client = data->client;
981 	struct reg *regp = &reg[index];
982 	int err;
983 
984 	/* +16 degrees offset for temp2 for the LM99 */
985 	if (data->kind == lm99 && index <= 2)
986 		val -= 16000;
987 
988 	if (data->kind == adt7461 || data->kind == tmp451)
989 		data->temp11[index] = temp_to_u16_adt7461(data, val);
990 	else if (data->kind == max6646)
991 		data->temp11[index] = temp_to_u8(val) << 8;
992 	else if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
993 		data->temp11[index] = temp_to_s16(val);
994 	else
995 		data->temp11[index] = temp_to_s8(val) << 8;
996 
997 	lm90_select_remote_channel(client, data, index >= 3);
998 	err = i2c_smbus_write_byte_data(client, regp->high,
999 				  data->temp11[index] >> 8);
1000 	if (err < 0)
1001 		return err;
1002 	if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
1003 		err = i2c_smbus_write_byte_data(client, regp->low,
1004 						data->temp11[index] & 0xff);
1005 
1006 	lm90_select_remote_channel(client, data, 0);
1007 	return err;
1008 }
1009 
1010 static int lm90_get_temp8(struct lm90_data *data, int index)
1011 {
1012 	s8 temp8 = data->temp8[index];
1013 	int temp;
1014 
1015 	if (data->kind == adt7461 || data->kind == tmp451)
1016 		temp = temp_from_u8_adt7461(data, temp8);
1017 	else if (data->kind == max6646)
1018 		temp = temp_from_u8(temp8);
1019 	else
1020 		temp = temp_from_s8(temp8);
1021 
1022 	/* +16 degrees offset for temp2 for the LM99 */
1023 	if (data->kind == lm99 && index == 3)
1024 		temp += 16000;
1025 
1026 	return temp;
1027 }
1028 
1029 static int lm90_set_temp8(struct lm90_data *data, int index, long val)
1030 {
1031 	static const u8 reg[TEMP8_REG_NUM] = {
1032 		LM90_REG_W_LOCAL_LOW,
1033 		LM90_REG_W_LOCAL_HIGH,
1034 		LM90_REG_W_LOCAL_CRIT,
1035 		LM90_REG_W_REMOTE_CRIT,
1036 		MAX6659_REG_W_LOCAL_EMERG,
1037 		MAX6659_REG_W_REMOTE_EMERG,
1038 		LM90_REG_W_REMOTE_CRIT,
1039 		MAX6659_REG_W_REMOTE_EMERG,
1040 	};
1041 	struct i2c_client *client = data->client;
1042 	int err;
1043 
1044 	/* +16 degrees offset for temp2 for the LM99 */
1045 	if (data->kind == lm99 && index == 3)
1046 		val -= 16000;
1047 
1048 	if (data->kind == adt7461 || data->kind == tmp451)
1049 		data->temp8[index] = temp_to_u8_adt7461(data, val);
1050 	else if (data->kind == max6646)
1051 		data->temp8[index] = temp_to_u8(val);
1052 	else
1053 		data->temp8[index] = temp_to_s8(val);
1054 
1055 	lm90_select_remote_channel(client, data, index >= 6);
1056 	err = i2c_smbus_write_byte_data(client, reg[index], data->temp8[index]);
1057 	lm90_select_remote_channel(client, data, 0);
1058 
1059 	return err;
1060 }
1061 
1062 static int lm90_get_temphyst(struct lm90_data *data, int index)
1063 {
1064 	int temp;
1065 
1066 	if (data->kind == adt7461 || data->kind == tmp451)
1067 		temp = temp_from_u8_adt7461(data, data->temp8[index]);
1068 	else if (data->kind == max6646)
1069 		temp = temp_from_u8(data->temp8[index]);
1070 	else
1071 		temp = temp_from_s8(data->temp8[index]);
1072 
1073 	/* +16 degrees offset for temp2 for the LM99 */
1074 	if (data->kind == lm99 && index == 3)
1075 		temp += 16000;
1076 
1077 	return temp - temp_from_s8(data->temp_hyst);
1078 }
1079 
1080 static int lm90_set_temphyst(struct lm90_data *data, long val)
1081 {
1082 	struct i2c_client *client = data->client;
1083 	int temp;
1084 	int err;
1085 
1086 	if (data->kind == adt7461 || data->kind == tmp451)
1087 		temp = temp_from_u8_adt7461(data, data->temp8[LOCAL_CRIT]);
1088 	else if (data->kind == max6646)
1089 		temp = temp_from_u8(data->temp8[LOCAL_CRIT]);
1090 	else
1091 		temp = temp_from_s8(data->temp8[LOCAL_CRIT]);
1092 
1093 	data->temp_hyst = hyst_to_reg(temp - val);
1094 	err = i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
1095 					data->temp_hyst);
1096 	return err;
1097 }
1098 
1099 static const u8 lm90_temp_index[3] = {
1100 	LOCAL_TEMP, REMOTE_TEMP, REMOTE2_TEMP
1101 };
1102 
1103 static const u8 lm90_temp_min_index[3] = {
1104 	LOCAL_LOW, REMOTE_LOW, REMOTE2_LOW
1105 };
1106 
1107 static const u8 lm90_temp_max_index[3] = {
1108 	LOCAL_HIGH, REMOTE_HIGH, REMOTE2_HIGH
1109 };
1110 
1111 static const u8 lm90_temp_crit_index[3] = {
1112 	LOCAL_CRIT, REMOTE_CRIT, REMOTE2_CRIT
1113 };
1114 
1115 static const u8 lm90_temp_emerg_index[3] = {
1116 	LOCAL_EMERG, REMOTE_EMERG, REMOTE2_EMERG
1117 };
1118 
1119 static const u8 lm90_min_alarm_bits[3] = { 5, 3, 11 };
1120 static const u8 lm90_max_alarm_bits[3] = { 6, 4, 12 };
1121 static const u8 lm90_crit_alarm_bits[3] = { 0, 1, 9 };
1122 static const u8 lm90_emergency_alarm_bits[3] = { 15, 13, 14 };
1123 static const u8 lm90_fault_bits[3] = { 0, 2, 10 };
1124 
1125 static int lm90_temp_read(struct device *dev, u32 attr, int channel, long *val)
1126 {
1127 	struct lm90_data *data = dev_get_drvdata(dev);
1128 	int err;
1129 
1130 	mutex_lock(&data->update_lock);
1131 	err = lm90_update_device(dev);
1132 	mutex_unlock(&data->update_lock);
1133 	if (err)
1134 		return err;
1135 
1136 	switch (attr) {
1137 	case hwmon_temp_input:
1138 		*val = lm90_get_temp11(data, lm90_temp_index[channel]);
1139 		break;
1140 	case hwmon_temp_min_alarm:
1141 		*val = (data->alarms >> lm90_min_alarm_bits[channel]) & 1;
1142 		break;
1143 	case hwmon_temp_max_alarm:
1144 		*val = (data->alarms >> lm90_max_alarm_bits[channel]) & 1;
1145 		break;
1146 	case hwmon_temp_crit_alarm:
1147 		*val = (data->alarms >> lm90_crit_alarm_bits[channel]) & 1;
1148 		break;
1149 	case hwmon_temp_emergency_alarm:
1150 		*val = (data->alarms >> lm90_emergency_alarm_bits[channel]) & 1;
1151 		break;
1152 	case hwmon_temp_fault:
1153 		*val = (data->alarms >> lm90_fault_bits[channel]) & 1;
1154 		break;
1155 	case hwmon_temp_min:
1156 		if (channel == 0)
1157 			*val = lm90_get_temp8(data,
1158 					      lm90_temp_min_index[channel]);
1159 		else
1160 			*val = lm90_get_temp11(data,
1161 					       lm90_temp_min_index[channel]);
1162 		break;
1163 	case hwmon_temp_max:
1164 		if (channel == 0)
1165 			*val = lm90_get_temp8(data,
1166 					      lm90_temp_max_index[channel]);
1167 		else
1168 			*val = lm90_get_temp11(data,
1169 					       lm90_temp_max_index[channel]);
1170 		break;
1171 	case hwmon_temp_crit:
1172 		*val = lm90_get_temp8(data, lm90_temp_crit_index[channel]);
1173 		break;
1174 	case hwmon_temp_crit_hyst:
1175 		*val = lm90_get_temphyst(data, lm90_temp_crit_index[channel]);
1176 		break;
1177 	case hwmon_temp_emergency:
1178 		*val = lm90_get_temp8(data, lm90_temp_emerg_index[channel]);
1179 		break;
1180 	case hwmon_temp_emergency_hyst:
1181 		*val = lm90_get_temphyst(data, lm90_temp_emerg_index[channel]);
1182 		break;
1183 	case hwmon_temp_offset:
1184 		*val = lm90_get_temp11(data, REMOTE_OFFSET);
1185 		break;
1186 	default:
1187 		return -EOPNOTSUPP;
1188 	}
1189 	return 0;
1190 }
1191 
1192 static int lm90_temp_write(struct device *dev, u32 attr, int channel, long val)
1193 {
1194 	struct lm90_data *data = dev_get_drvdata(dev);
1195 	int err;
1196 
1197 	mutex_lock(&data->update_lock);
1198 
1199 	err = lm90_update_device(dev);
1200 	if (err)
1201 		goto error;
1202 
1203 	switch (attr) {
1204 	case hwmon_temp_min:
1205 		if (channel == 0)
1206 			err = lm90_set_temp8(data,
1207 					      lm90_temp_min_index[channel],
1208 					      val);
1209 		else
1210 			err = lm90_set_temp11(data,
1211 					      lm90_temp_min_index[channel],
1212 					      val);
1213 		break;
1214 	case hwmon_temp_max:
1215 		if (channel == 0)
1216 			err = lm90_set_temp8(data,
1217 					     lm90_temp_max_index[channel],
1218 					     val);
1219 		else
1220 			err = lm90_set_temp11(data,
1221 					      lm90_temp_max_index[channel],
1222 					      val);
1223 		break;
1224 	case hwmon_temp_crit:
1225 		err = lm90_set_temp8(data, lm90_temp_crit_index[channel], val);
1226 		break;
1227 	case hwmon_temp_crit_hyst:
1228 		err = lm90_set_temphyst(data, val);
1229 		break;
1230 	case hwmon_temp_emergency:
1231 		err = lm90_set_temp8(data, lm90_temp_emerg_index[channel], val);
1232 		break;
1233 	case hwmon_temp_offset:
1234 		err = lm90_set_temp11(data, REMOTE_OFFSET, val);
1235 		break;
1236 	default:
1237 		err = -EOPNOTSUPP;
1238 		break;
1239 	}
1240 error:
1241 	mutex_unlock(&data->update_lock);
1242 
1243 	return err;
1244 }
1245 
1246 static umode_t lm90_temp_is_visible(const void *data, u32 attr, int channel)
1247 {
1248 	switch (attr) {
1249 	case hwmon_temp_input:
1250 	case hwmon_temp_min_alarm:
1251 	case hwmon_temp_max_alarm:
1252 	case hwmon_temp_crit_alarm:
1253 	case hwmon_temp_emergency_alarm:
1254 	case hwmon_temp_emergency_hyst:
1255 	case hwmon_temp_fault:
1256 		return 0444;
1257 	case hwmon_temp_min:
1258 	case hwmon_temp_max:
1259 	case hwmon_temp_crit:
1260 	case hwmon_temp_emergency:
1261 	case hwmon_temp_offset:
1262 		return 0644;
1263 	case hwmon_temp_crit_hyst:
1264 		if (channel == 0)
1265 			return 0644;
1266 		return 0444;
1267 	default:
1268 		return 0;
1269 	}
1270 }
1271 
1272 static int lm90_chip_read(struct device *dev, u32 attr, int channel, long *val)
1273 {
1274 	struct lm90_data *data = dev_get_drvdata(dev);
1275 	int err;
1276 
1277 	mutex_lock(&data->update_lock);
1278 	err = lm90_update_device(dev);
1279 	mutex_unlock(&data->update_lock);
1280 	if (err)
1281 		return err;
1282 
1283 	switch (attr) {
1284 	case hwmon_chip_update_interval:
1285 		*val = data->update_interval;
1286 		break;
1287 	case hwmon_chip_alarms:
1288 		*val = data->alarms;
1289 		break;
1290 	default:
1291 		return -EOPNOTSUPP;
1292 	}
1293 
1294 	return 0;
1295 }
1296 
1297 static int lm90_chip_write(struct device *dev, u32 attr, int channel, long val)
1298 {
1299 	struct lm90_data *data = dev_get_drvdata(dev);
1300 	struct i2c_client *client = data->client;
1301 	int err;
1302 
1303 	mutex_lock(&data->update_lock);
1304 
1305 	err = lm90_update_device(dev);
1306 	if (err)
1307 		goto error;
1308 
1309 	switch (attr) {
1310 	case hwmon_chip_update_interval:
1311 		err = lm90_set_convrate(client, data,
1312 					clamp_val(val, 0, 100000));
1313 		break;
1314 	default:
1315 		err = -EOPNOTSUPP;
1316 		break;
1317 	}
1318 error:
1319 	mutex_unlock(&data->update_lock);
1320 
1321 	return err;
1322 }
1323 
1324 static umode_t lm90_chip_is_visible(const void *data, u32 attr, int channel)
1325 {
1326 	switch (attr) {
1327 	case hwmon_chip_update_interval:
1328 		return 0644;
1329 	case hwmon_chip_alarms:
1330 		return 0444;
1331 	default:
1332 		return 0;
1333 	}
1334 }
1335 
1336 static int lm90_read(struct device *dev, enum hwmon_sensor_types type,
1337 		     u32 attr, int channel, long *val)
1338 {
1339 	switch (type) {
1340 	case hwmon_chip:
1341 		return lm90_chip_read(dev, attr, channel, val);
1342 	case hwmon_temp:
1343 		return lm90_temp_read(dev, attr, channel, val);
1344 	default:
1345 		return -EOPNOTSUPP;
1346 	}
1347 }
1348 
1349 static int lm90_write(struct device *dev, enum hwmon_sensor_types type,
1350 		      u32 attr, int channel, long val)
1351 {
1352 	switch (type) {
1353 	case hwmon_chip:
1354 		return lm90_chip_write(dev, attr, channel, val);
1355 	case hwmon_temp:
1356 		return lm90_temp_write(dev, attr, channel, val);
1357 	default:
1358 		return -EOPNOTSUPP;
1359 	}
1360 }
1361 
1362 static umode_t lm90_is_visible(const void *data, enum hwmon_sensor_types type,
1363 			       u32 attr, int channel)
1364 {
1365 	switch (type) {
1366 	case hwmon_chip:
1367 		return lm90_chip_is_visible(data, attr, channel);
1368 	case hwmon_temp:
1369 		return lm90_temp_is_visible(data, attr, channel);
1370 	default:
1371 		return 0;
1372 	}
1373 }
1374 
1375 /* Return 0 if detection is successful, -ENODEV otherwise */
1376 static int lm90_detect(struct i2c_client *client,
1377 		       struct i2c_board_info *info)
1378 {
1379 	struct i2c_adapter *adapter = client->adapter;
1380 	int address = client->addr;
1381 	const char *name = NULL;
1382 	int man_id, chip_id, config1, config2, convrate;
1383 
1384 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
1385 		return -ENODEV;
1386 
1387 	/* detection and identification */
1388 	man_id = i2c_smbus_read_byte_data(client, LM90_REG_R_MAN_ID);
1389 	chip_id = i2c_smbus_read_byte_data(client, LM90_REG_R_CHIP_ID);
1390 	config1 = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG1);
1391 	convrate = i2c_smbus_read_byte_data(client, LM90_REG_R_CONVRATE);
1392 	if (man_id < 0 || chip_id < 0 || config1 < 0 || convrate < 0)
1393 		return -ENODEV;
1394 
1395 	if (man_id == 0x01 || man_id == 0x5C || man_id == 0x41) {
1396 		config2 = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG2);
1397 		if (config2 < 0)
1398 			return -ENODEV;
1399 	} else
1400 		config2 = 0;		/* Make compiler happy */
1401 
1402 	if ((address == 0x4C || address == 0x4D)
1403 	 && man_id == 0x01) { /* National Semiconductor */
1404 		if ((config1 & 0x2A) == 0x00
1405 		 && (config2 & 0xF8) == 0x00
1406 		 && convrate <= 0x09) {
1407 			if (address == 0x4C
1408 			 && (chip_id & 0xF0) == 0x20) { /* LM90 */
1409 				name = "lm90";
1410 			} else
1411 			if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
1412 				name = "lm99";
1413 				dev_info(&adapter->dev,
1414 					 "Assuming LM99 chip at 0x%02x\n",
1415 					 address);
1416 				dev_info(&adapter->dev,
1417 					 "If it is an LM89, instantiate it "
1418 					 "with the new_device sysfs "
1419 					 "interface\n");
1420 			} else
1421 			if (address == 0x4C
1422 			 && (chip_id & 0xF0) == 0x10) { /* LM86 */
1423 				name = "lm86";
1424 			}
1425 		}
1426 	} else
1427 	if ((address == 0x4C || address == 0x4D)
1428 	 && man_id == 0x41) { /* Analog Devices */
1429 		if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
1430 		 && (config1 & 0x3F) == 0x00
1431 		 && convrate <= 0x0A) {
1432 			name = "adm1032";
1433 			/*
1434 			 * The ADM1032 supports PEC, but only if combined
1435 			 * transactions are not used.
1436 			 */
1437 			if (i2c_check_functionality(adapter,
1438 						    I2C_FUNC_SMBUS_BYTE))
1439 				info->flags |= I2C_CLIENT_PEC;
1440 		} else
1441 		if (chip_id == 0x51 /* ADT7461 */
1442 		 && (config1 & 0x1B) == 0x00
1443 		 && convrate <= 0x0A) {
1444 			name = "adt7461";
1445 		} else
1446 		if (chip_id == 0x57 /* ADT7461A, NCT1008 */
1447 		 && (config1 & 0x1B) == 0x00
1448 		 && convrate <= 0x0A) {
1449 			name = "adt7461a";
1450 		}
1451 	} else
1452 	if (man_id == 0x4D) { /* Maxim */
1453 		int emerg, emerg2, status2;
1454 
1455 		/*
1456 		 * We read MAX6659_REG_R_REMOTE_EMERG twice, and re-read
1457 		 * LM90_REG_R_MAN_ID in between. If MAX6659_REG_R_REMOTE_EMERG
1458 		 * exists, both readings will reflect the same value. Otherwise,
1459 		 * the readings will be different.
1460 		 */
1461 		emerg = i2c_smbus_read_byte_data(client,
1462 						 MAX6659_REG_R_REMOTE_EMERG);
1463 		man_id = i2c_smbus_read_byte_data(client,
1464 						  LM90_REG_R_MAN_ID);
1465 		emerg2 = i2c_smbus_read_byte_data(client,
1466 						  MAX6659_REG_R_REMOTE_EMERG);
1467 		status2 = i2c_smbus_read_byte_data(client,
1468 						   MAX6696_REG_R_STATUS2);
1469 		if (emerg < 0 || man_id < 0 || emerg2 < 0 || status2 < 0)
1470 			return -ENODEV;
1471 
1472 		/*
1473 		 * The MAX6657, MAX6658 and MAX6659 do NOT have a chip_id
1474 		 * register. Reading from that address will return the last
1475 		 * read value, which in our case is those of the man_id
1476 		 * register. Likewise, the config1 register seems to lack a
1477 		 * low nibble, so the value will be those of the previous
1478 		 * read, so in our case those of the man_id register.
1479 		 * MAX6659 has a third set of upper temperature limit registers.
1480 		 * Those registers also return values on MAX6657 and MAX6658,
1481 		 * thus the only way to detect MAX6659 is by its address.
1482 		 * For this reason it will be mis-detected as MAX6657 if its
1483 		 * address is 0x4C.
1484 		 */
1485 		if (chip_id == man_id
1486 		 && (address == 0x4C || address == 0x4D || address == 0x4E)
1487 		 && (config1 & 0x1F) == (man_id & 0x0F)
1488 		 && convrate <= 0x09) {
1489 			if (address == 0x4C)
1490 				name = "max6657";
1491 			else
1492 				name = "max6659";
1493 		} else
1494 		/*
1495 		 * Even though MAX6695 and MAX6696 do not have a chip ID
1496 		 * register, reading it returns 0x01. Bit 4 of the config1
1497 		 * register is unused and should return zero when read. Bit 0 of
1498 		 * the status2 register is unused and should return zero when
1499 		 * read.
1500 		 *
1501 		 * MAX6695 and MAX6696 have an additional set of temperature
1502 		 * limit registers. We can detect those chips by checking if
1503 		 * one of those registers exists.
1504 		 */
1505 		if (chip_id == 0x01
1506 		 && (config1 & 0x10) == 0x00
1507 		 && (status2 & 0x01) == 0x00
1508 		 && emerg == emerg2
1509 		 && convrate <= 0x07) {
1510 			name = "max6696";
1511 		} else
1512 		/*
1513 		 * The chip_id register of the MAX6680 and MAX6681 holds the
1514 		 * revision of the chip. The lowest bit of the config1 register
1515 		 * is unused and should return zero when read, so should the
1516 		 * second to last bit of config1 (software reset).
1517 		 */
1518 		if (chip_id == 0x01
1519 		 && (config1 & 0x03) == 0x00
1520 		 && convrate <= 0x07) {
1521 			name = "max6680";
1522 		} else
1523 		/*
1524 		 * The chip_id register of the MAX6646/6647/6649 holds the
1525 		 * revision of the chip. The lowest 6 bits of the config1
1526 		 * register are unused and should return zero when read.
1527 		 */
1528 		if (chip_id == 0x59
1529 		 && (config1 & 0x3f) == 0x00
1530 		 && convrate <= 0x07) {
1531 			name = "max6646";
1532 		}
1533 	} else
1534 	if (address == 0x4C
1535 	 && man_id == 0x5C) { /* Winbond/Nuvoton */
1536 		if ((config1 & 0x2A) == 0x00
1537 		 && (config2 & 0xF8) == 0x00) {
1538 			if (chip_id == 0x01 /* W83L771W/G */
1539 			 && convrate <= 0x09) {
1540 				name = "w83l771";
1541 			} else
1542 			if ((chip_id & 0xFE) == 0x10 /* W83L771AWG/ASG */
1543 			 && convrate <= 0x08) {
1544 				name = "w83l771";
1545 			}
1546 		}
1547 	} else
1548 	if (address >= 0x48 && address <= 0x4F
1549 	 && man_id == 0xA1) { /*  NXP Semiconductor/Philips */
1550 		if (chip_id == 0x00
1551 		 && (config1 & 0x2A) == 0x00
1552 		 && (config2 & 0xFE) == 0x00
1553 		 && convrate <= 0x09) {
1554 			name = "sa56004";
1555 		}
1556 	} else
1557 	if ((address == 0x4C || address == 0x4D)
1558 	 && man_id == 0x47) { /* GMT */
1559 		if (chip_id == 0x01 /* G781 */
1560 		 && (config1 & 0x3F) == 0x00
1561 		 && convrate <= 0x08)
1562 			name = "g781";
1563 	} else
1564 	if (address == 0x4C
1565 	 && man_id == 0x55) { /* Texas Instruments */
1566 		int local_ext;
1567 
1568 		local_ext = i2c_smbus_read_byte_data(client,
1569 						     TMP451_REG_R_LOCAL_TEMPL);
1570 
1571 		if (chip_id == 0x00 /* TMP451 */
1572 		 && (config1 & 0x1B) == 0x00
1573 		 && convrate <= 0x09
1574 		 && (local_ext & 0x0F) == 0x00)
1575 			name = "tmp451";
1576 	}
1577 
1578 	if (!name) { /* identification failed */
1579 		dev_dbg(&adapter->dev,
1580 			"Unsupported chip at 0x%02x (man_id=0x%02X, "
1581 			"chip_id=0x%02X)\n", address, man_id, chip_id);
1582 		return -ENODEV;
1583 	}
1584 
1585 	strlcpy(info->type, name, I2C_NAME_SIZE);
1586 
1587 	return 0;
1588 }
1589 
1590 static void lm90_restore_conf(void *_data)
1591 {
1592 	struct lm90_data *data = _data;
1593 	struct i2c_client *client = data->client;
1594 
1595 	/* Restore initial configuration */
1596 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
1597 				  data->convrate_orig);
1598 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
1599 				  data->config_orig);
1600 }
1601 
1602 static int lm90_init_client(struct i2c_client *client, struct lm90_data *data)
1603 {
1604 	int config, convrate;
1605 
1606 	convrate = lm90_read_reg(client, LM90_REG_R_CONVRATE);
1607 	if (convrate < 0)
1608 		return convrate;
1609 	data->convrate_orig = convrate;
1610 
1611 	/*
1612 	 * Start the conversions.
1613 	 */
1614 	lm90_set_convrate(client, data, 500);	/* 500ms; 2Hz conversion rate */
1615 	config = lm90_read_reg(client, LM90_REG_R_CONFIG1);
1616 	if (config < 0)
1617 		return config;
1618 	data->config_orig = config;
1619 
1620 	/* Check Temperature Range Select */
1621 	if (data->kind == adt7461 || data->kind == tmp451) {
1622 		if (config & 0x04)
1623 			data->flags |= LM90_FLAG_ADT7461_EXT;
1624 	}
1625 
1626 	/*
1627 	 * Put MAX6680/MAX8881 into extended resolution (bit 0x10,
1628 	 * 0.125 degree resolution) and range (0x08, extend range
1629 	 * to -64 degree) mode for the remote temperature sensor.
1630 	 */
1631 	if (data->kind == max6680)
1632 		config |= 0x18;
1633 
1634 	/*
1635 	 * Select external channel 0 for max6695/96
1636 	 */
1637 	if (data->kind == max6696)
1638 		config &= ~0x08;
1639 
1640 	config &= 0xBF;	/* run */
1641 	if (config != data->config_orig) /* Only write if changed */
1642 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config);
1643 
1644 	return devm_add_action_or_reset(&client->dev, lm90_restore_conf, data);
1645 }
1646 
1647 static bool lm90_is_tripped(struct i2c_client *client, u16 *status)
1648 {
1649 	struct lm90_data *data = i2c_get_clientdata(client);
1650 	int st, st2 = 0;
1651 
1652 	st = lm90_read_reg(client, LM90_REG_R_STATUS);
1653 	if (st < 0)
1654 		return false;
1655 
1656 	if (data->kind == max6696) {
1657 		st2 = lm90_read_reg(client, MAX6696_REG_R_STATUS2);
1658 		if (st2 < 0)
1659 			return false;
1660 	}
1661 
1662 	*status = st | (st2 << 8);
1663 
1664 	if ((st & 0x7f) == 0 && (st2 & 0xfe) == 0)
1665 		return false;
1666 
1667 	if ((st & (LM90_STATUS_LLOW | LM90_STATUS_LHIGH | LM90_STATUS_LTHRM)) ||
1668 	    (st2 & MAX6696_STATUS2_LOT2))
1669 		dev_warn(&client->dev,
1670 			 "temp%d out of range, please check!\n", 1);
1671 	if ((st & (LM90_STATUS_RLOW | LM90_STATUS_RHIGH | LM90_STATUS_RTHRM)) ||
1672 	    (st2 & MAX6696_STATUS2_ROT2))
1673 		dev_warn(&client->dev,
1674 			 "temp%d out of range, please check!\n", 2);
1675 	if (st & LM90_STATUS_ROPEN)
1676 		dev_warn(&client->dev,
1677 			 "temp%d diode open, please check!\n", 2);
1678 	if (st2 & (MAX6696_STATUS2_R2LOW | MAX6696_STATUS2_R2HIGH |
1679 		   MAX6696_STATUS2_R2THRM | MAX6696_STATUS2_R2OT2))
1680 		dev_warn(&client->dev,
1681 			 "temp%d out of range, please check!\n", 3);
1682 	if (st2 & MAX6696_STATUS2_R2OPEN)
1683 		dev_warn(&client->dev,
1684 			 "temp%d diode open, please check!\n", 3);
1685 
1686 	return true;
1687 }
1688 
1689 static irqreturn_t lm90_irq_thread(int irq, void *dev_id)
1690 {
1691 	struct i2c_client *client = dev_id;
1692 	u16 status;
1693 
1694 	if (lm90_is_tripped(client, &status))
1695 		return IRQ_HANDLED;
1696 	else
1697 		return IRQ_NONE;
1698 }
1699 
1700 static void lm90_remove_pec(void *dev)
1701 {
1702 	device_remove_file(dev, &dev_attr_pec);
1703 }
1704 
1705 static void lm90_regulator_disable(void *regulator)
1706 {
1707 	regulator_disable(regulator);
1708 }
1709 
1710 
1711 static const struct hwmon_ops lm90_ops = {
1712 	.is_visible = lm90_is_visible,
1713 	.read = lm90_read,
1714 	.write = lm90_write,
1715 };
1716 
1717 static int lm90_probe(struct i2c_client *client,
1718 		      const struct i2c_device_id *id)
1719 {
1720 	struct device *dev = &client->dev;
1721 	struct i2c_adapter *adapter = to_i2c_adapter(dev->parent);
1722 	struct hwmon_channel_info *info;
1723 	struct regulator *regulator;
1724 	struct device *hwmon_dev;
1725 	struct lm90_data *data;
1726 	int err;
1727 
1728 	regulator = devm_regulator_get(dev, "vcc");
1729 	if (IS_ERR(regulator))
1730 		return PTR_ERR(regulator);
1731 
1732 	err = regulator_enable(regulator);
1733 	if (err < 0) {
1734 		dev_err(dev, "Failed to enable regulator: %d\n", err);
1735 		return err;
1736 	}
1737 
1738 	err = devm_add_action_or_reset(dev, lm90_regulator_disable, regulator);
1739 	if (err)
1740 		return err;
1741 
1742 	data = devm_kzalloc(dev, sizeof(struct lm90_data), GFP_KERNEL);
1743 	if (!data)
1744 		return -ENOMEM;
1745 
1746 	data->client = client;
1747 	i2c_set_clientdata(client, data);
1748 	mutex_init(&data->update_lock);
1749 
1750 	/* Set the device type */
1751 	if (client->dev.of_node)
1752 		data->kind = (enum chips)of_device_get_match_data(&client->dev);
1753 	else
1754 		data->kind = id->driver_data;
1755 	if (data->kind == adm1032) {
1756 		if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
1757 			client->flags &= ~I2C_CLIENT_PEC;
1758 	}
1759 
1760 	/*
1761 	 * Different devices have different alarm bits triggering the
1762 	 * ALERT# output
1763 	 */
1764 	data->alert_alarms = lm90_params[data->kind].alert_alarms;
1765 
1766 	/* Set chip capabilities */
1767 	data->flags = lm90_params[data->kind].flags;
1768 
1769 	data->chip.ops = &lm90_ops;
1770 	data->chip.info = data->info;
1771 
1772 	data->info[0] = HWMON_CHANNEL_INFO(chip,
1773 		HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL | HWMON_C_ALARMS);
1774 	data->info[1] = &data->temp_info;
1775 
1776 	info = &data->temp_info;
1777 	info->type = hwmon_temp;
1778 	info->config = data->channel_config;
1779 
1780 	data->channel_config[0] = HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
1781 		HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
1782 		HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM;
1783 	data->channel_config[1] = HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
1784 		HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
1785 		HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT;
1786 
1787 	if (data->flags & LM90_HAVE_OFFSET)
1788 		data->channel_config[1] |= HWMON_T_OFFSET;
1789 
1790 	if (data->flags & LM90_HAVE_EMERGENCY) {
1791 		data->channel_config[0] |= HWMON_T_EMERGENCY |
1792 			HWMON_T_EMERGENCY_HYST;
1793 		data->channel_config[1] |= HWMON_T_EMERGENCY |
1794 			HWMON_T_EMERGENCY_HYST;
1795 	}
1796 
1797 	if (data->flags & LM90_HAVE_EMERGENCY_ALARM) {
1798 		data->channel_config[0] |= HWMON_T_EMERGENCY_ALARM;
1799 		data->channel_config[1] |= HWMON_T_EMERGENCY_ALARM;
1800 	}
1801 
1802 	if (data->flags & LM90_HAVE_TEMP3) {
1803 		data->channel_config[2] = HWMON_T_INPUT |
1804 			HWMON_T_MIN | HWMON_T_MAX |
1805 			HWMON_T_CRIT | HWMON_T_CRIT_HYST |
1806 			HWMON_T_EMERGENCY | HWMON_T_EMERGENCY_HYST |
1807 			HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
1808 			HWMON_T_CRIT_ALARM | HWMON_T_EMERGENCY_ALARM |
1809 			HWMON_T_FAULT;
1810 	}
1811 
1812 	data->reg_local_ext = lm90_params[data->kind].reg_local_ext;
1813 
1814 	/* Set maximum conversion rate */
1815 	data->max_convrate = lm90_params[data->kind].max_convrate;
1816 
1817 	/* Initialize the LM90 chip */
1818 	err = lm90_init_client(client, data);
1819 	if (err < 0) {
1820 		dev_err(dev, "Failed to initialize device\n");
1821 		return err;
1822 	}
1823 
1824 	/*
1825 	 * The 'pec' attribute is attached to the i2c device and thus created
1826 	 * separately.
1827 	 */
1828 	if (client->flags & I2C_CLIENT_PEC) {
1829 		err = device_create_file(dev, &dev_attr_pec);
1830 		if (err)
1831 			return err;
1832 		err = devm_add_action_or_reset(dev, lm90_remove_pec, dev);
1833 		if (err)
1834 			return err;
1835 	}
1836 
1837 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
1838 							 data, &data->chip,
1839 							 NULL);
1840 	if (IS_ERR(hwmon_dev))
1841 		return PTR_ERR(hwmon_dev);
1842 
1843 	if (client->irq) {
1844 		dev_dbg(dev, "IRQ: %d\n", client->irq);
1845 		err = devm_request_threaded_irq(dev, client->irq,
1846 						NULL, lm90_irq_thread,
1847 						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
1848 						"lm90", client);
1849 		if (err < 0) {
1850 			dev_err(dev, "cannot request IRQ %d\n", client->irq);
1851 			return err;
1852 		}
1853 	}
1854 
1855 	return 0;
1856 }
1857 
1858 static void lm90_alert(struct i2c_client *client, enum i2c_alert_protocol type,
1859 		       unsigned int flag)
1860 {
1861 	u16 alarms;
1862 
1863 	if (type != I2C_PROTOCOL_SMBUS_ALERT)
1864 		return;
1865 
1866 	if (lm90_is_tripped(client, &alarms)) {
1867 		/*
1868 		 * Disable ALERT# output, because these chips don't implement
1869 		 * SMBus alert correctly; they should only hold the alert line
1870 		 * low briefly.
1871 		 */
1872 		struct lm90_data *data = i2c_get_clientdata(client);
1873 
1874 		if ((data->flags & LM90_HAVE_BROKEN_ALERT) &&
1875 		    (alarms & data->alert_alarms)) {
1876 			int config;
1877 
1878 			dev_dbg(&client->dev, "Disabling ALERT#\n");
1879 			config = lm90_read_reg(client, LM90_REG_R_CONFIG1);
1880 			if (config >= 0)
1881 				i2c_smbus_write_byte_data(client,
1882 							  LM90_REG_W_CONFIG1,
1883 							  config | 0x80);
1884 		}
1885 	} else {
1886 		dev_info(&client->dev, "Everything OK\n");
1887 	}
1888 }
1889 
1890 static struct i2c_driver lm90_driver = {
1891 	.class		= I2C_CLASS_HWMON,
1892 	.driver = {
1893 		.name	= "lm90",
1894 		.of_match_table = of_match_ptr(lm90_of_match),
1895 	},
1896 	.probe		= lm90_probe,
1897 	.alert		= lm90_alert,
1898 	.id_table	= lm90_id,
1899 	.detect		= lm90_detect,
1900 	.address_list	= normal_i2c,
1901 };
1902 
1903 module_i2c_driver(lm90_driver);
1904 
1905 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
1906 MODULE_DESCRIPTION("LM90/ADM1032 driver");
1907 MODULE_LICENSE("GPL");
1908