xref: /openbmc/linux/drivers/hwmon/lm90.c (revision 5104d265)
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  * Since the LM90 was the first chipset supported by this driver, most
64  * comments will refer to this chipset, but are actually general and
65  * concern all supported chipsets, unless mentioned otherwise.
66  *
67  * This program is free software; you can redistribute it and/or modify
68  * it under the terms of the GNU General Public License as published by
69  * the Free Software Foundation; either version 2 of the License, or
70  * (at your option) any later version.
71  *
72  * This program is distributed in the hope that it will be useful,
73  * but WITHOUT ANY WARRANTY; without even the implied warranty of
74  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
75  * GNU General Public License for more details.
76  *
77  * You should have received a copy of the GNU General Public License
78  * along with this program; if not, write to the Free Software
79  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
80  */
81 
82 #include <linux/module.h>
83 #include <linux/init.h>
84 #include <linux/slab.h>
85 #include <linux/jiffies.h>
86 #include <linux/i2c.h>
87 #include <linux/hwmon-sysfs.h>
88 #include <linux/hwmon.h>
89 #include <linux/err.h>
90 #include <linux/mutex.h>
91 #include <linux/sysfs.h>
92 
93 /*
94  * Addresses to scan
95  * Address is fully defined internally and cannot be changed except for
96  * MAX6659, MAX6680 and MAX6681.
97  * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, ADT7461A, MAX6649,
98  * MAX6657, MAX6658, NCT1008 and W83L771 have address 0x4c.
99  * ADM1032-2, ADT7461-2, ADT7461A-2, LM89-1, LM99-1, MAX6646, and NCT1008D
100  * have address 0x4d.
101  * MAX6647 has address 0x4e.
102  * MAX6659 can have address 0x4c, 0x4d or 0x4e.
103  * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
104  * 0x4c, 0x4d or 0x4e.
105  * SA56004 can have address 0x48 through 0x4F.
106  */
107 
108 static const unsigned short normal_i2c[] = {
109 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x48, 0x49, 0x4a, 0x4b, 0x4c,
110 	0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
111 
112 enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
113 	max6646, w83l771, max6696, sa56004, g781 };
114 
115 /*
116  * The LM90 registers
117  */
118 
119 #define LM90_REG_R_MAN_ID		0xFE
120 #define LM90_REG_R_CHIP_ID		0xFF
121 #define LM90_REG_R_CONFIG1		0x03
122 #define LM90_REG_W_CONFIG1		0x09
123 #define LM90_REG_R_CONFIG2		0xBF
124 #define LM90_REG_W_CONFIG2		0xBF
125 #define LM90_REG_R_CONVRATE		0x04
126 #define LM90_REG_W_CONVRATE		0x0A
127 #define LM90_REG_R_STATUS		0x02
128 #define LM90_REG_R_LOCAL_TEMP		0x00
129 #define LM90_REG_R_LOCAL_HIGH		0x05
130 #define LM90_REG_W_LOCAL_HIGH		0x0B
131 #define LM90_REG_R_LOCAL_LOW		0x06
132 #define LM90_REG_W_LOCAL_LOW		0x0C
133 #define LM90_REG_R_LOCAL_CRIT		0x20
134 #define LM90_REG_W_LOCAL_CRIT		0x20
135 #define LM90_REG_R_REMOTE_TEMPH		0x01
136 #define LM90_REG_R_REMOTE_TEMPL		0x10
137 #define LM90_REG_R_REMOTE_OFFSH		0x11
138 #define LM90_REG_W_REMOTE_OFFSH		0x11
139 #define LM90_REG_R_REMOTE_OFFSL		0x12
140 #define LM90_REG_W_REMOTE_OFFSL		0x12
141 #define LM90_REG_R_REMOTE_HIGHH		0x07
142 #define LM90_REG_W_REMOTE_HIGHH		0x0D
143 #define LM90_REG_R_REMOTE_HIGHL		0x13
144 #define LM90_REG_W_REMOTE_HIGHL		0x13
145 #define LM90_REG_R_REMOTE_LOWH		0x08
146 #define LM90_REG_W_REMOTE_LOWH		0x0E
147 #define LM90_REG_R_REMOTE_LOWL		0x14
148 #define LM90_REG_W_REMOTE_LOWL		0x14
149 #define LM90_REG_R_REMOTE_CRIT		0x19
150 #define LM90_REG_W_REMOTE_CRIT		0x19
151 #define LM90_REG_R_TCRIT_HYST		0x21
152 #define LM90_REG_W_TCRIT_HYST		0x21
153 
154 /* MAX6646/6647/6649/6657/6658/6659/6695/6696 registers */
155 
156 #define MAX6657_REG_R_LOCAL_TEMPL	0x11
157 #define MAX6696_REG_R_STATUS2		0x12
158 #define MAX6659_REG_R_REMOTE_EMERG	0x16
159 #define MAX6659_REG_W_REMOTE_EMERG	0x16
160 #define MAX6659_REG_R_LOCAL_EMERG	0x17
161 #define MAX6659_REG_W_LOCAL_EMERG	0x17
162 
163 /*  SA56004 registers */
164 
165 #define SA56004_REG_R_LOCAL_TEMPL 0x22
166 
167 #define LM90_DEF_CONVRATE_RVAL	6	/* Def conversion rate register value */
168 #define LM90_MAX_CONVRATE_MS	16000	/* Maximum conversion rate in ms */
169 
170 /*
171  * Device flags
172  */
173 #define LM90_FLAG_ADT7461_EXT	(1 << 0) /* ADT7461 extended mode	*/
174 /* Device features */
175 #define LM90_HAVE_OFFSET	(1 << 1) /* temperature offset register	*/
176 #define LM90_HAVE_REM_LIMIT_EXT	(1 << 3) /* extended remote limit	*/
177 #define LM90_HAVE_EMERGENCY	(1 << 4) /* 3rd upper (emergency) limit	*/
178 #define LM90_HAVE_EMERGENCY_ALARM (1 << 5)/* emergency alarm		*/
179 #define LM90_HAVE_TEMP3		(1 << 6) /* 3rd temperature sensor	*/
180 #define LM90_HAVE_BROKEN_ALERT	(1 << 7) /* Broken alert		*/
181 
182 /*
183  * Driver data (common to all clients)
184  */
185 
186 static const struct i2c_device_id lm90_id[] = {
187 	{ "adm1032", adm1032 },
188 	{ "adt7461", adt7461 },
189 	{ "adt7461a", adt7461 },
190 	{ "g781", g781 },
191 	{ "lm90", lm90 },
192 	{ "lm86", lm86 },
193 	{ "lm89", lm86 },
194 	{ "lm99", lm99 },
195 	{ "max6646", max6646 },
196 	{ "max6647", max6646 },
197 	{ "max6649", max6646 },
198 	{ "max6657", max6657 },
199 	{ "max6658", max6657 },
200 	{ "max6659", max6659 },
201 	{ "max6680", max6680 },
202 	{ "max6681", max6680 },
203 	{ "max6695", max6696 },
204 	{ "max6696", max6696 },
205 	{ "nct1008", adt7461 },
206 	{ "w83l771", w83l771 },
207 	{ "sa56004", sa56004 },
208 	{ }
209 };
210 MODULE_DEVICE_TABLE(i2c, lm90_id);
211 
212 /*
213  * chip type specific parameters
214  */
215 struct lm90_params {
216 	u32 flags;		/* Capabilities */
217 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
218 				/* Upper 8 bits for max6695/96 */
219 	u8 max_convrate;	/* Maximum conversion rate register value */
220 	u8 reg_local_ext;	/* Extended local temp register (optional) */
221 };
222 
223 static const struct lm90_params lm90_params[] = {
224 	[adm1032] = {
225 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
226 		  | LM90_HAVE_BROKEN_ALERT,
227 		.alert_alarms = 0x7c,
228 		.max_convrate = 10,
229 	},
230 	[adt7461] = {
231 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
232 		  | LM90_HAVE_BROKEN_ALERT,
233 		.alert_alarms = 0x7c,
234 		.max_convrate = 10,
235 	},
236 	[g781] = {
237 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
238 		  | LM90_HAVE_BROKEN_ALERT,
239 		.alert_alarms = 0x7c,
240 		.max_convrate = 8,
241 	},
242 	[lm86] = {
243 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
244 		.alert_alarms = 0x7b,
245 		.max_convrate = 9,
246 	},
247 	[lm90] = {
248 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
249 		.alert_alarms = 0x7b,
250 		.max_convrate = 9,
251 	},
252 	[lm99] = {
253 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
254 		.alert_alarms = 0x7b,
255 		.max_convrate = 9,
256 	},
257 	[max6646] = {
258 		.alert_alarms = 0x7c,
259 		.max_convrate = 6,
260 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
261 	},
262 	[max6657] = {
263 		.alert_alarms = 0x7c,
264 		.max_convrate = 8,
265 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
266 	},
267 	[max6659] = {
268 		.flags = LM90_HAVE_EMERGENCY,
269 		.alert_alarms = 0x7c,
270 		.max_convrate = 8,
271 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
272 	},
273 	[max6680] = {
274 		.flags = LM90_HAVE_OFFSET,
275 		.alert_alarms = 0x7c,
276 		.max_convrate = 7,
277 	},
278 	[max6696] = {
279 		.flags = LM90_HAVE_EMERGENCY
280 		  | LM90_HAVE_EMERGENCY_ALARM | LM90_HAVE_TEMP3,
281 		.alert_alarms = 0x187c,
282 		.max_convrate = 6,
283 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
284 	},
285 	[w83l771] = {
286 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
287 		.alert_alarms = 0x7c,
288 		.max_convrate = 8,
289 	},
290 	[sa56004] = {
291 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
292 		.alert_alarms = 0x7b,
293 		.max_convrate = 9,
294 		.reg_local_ext = SA56004_REG_R_LOCAL_TEMPL,
295 	},
296 };
297 
298 /*
299  * Client data (each client gets its own)
300  */
301 
302 struct lm90_data {
303 	struct device *hwmon_dev;
304 	struct mutex update_lock;
305 	char valid; /* zero until following fields are valid */
306 	unsigned long last_updated; /* in jiffies */
307 	int kind;
308 	u32 flags;
309 
310 	int update_interval;	/* in milliseconds */
311 
312 	u8 config_orig;		/* Original configuration register value */
313 	u8 convrate_orig;	/* Original conversion rate register value */
314 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
315 				/* Upper 8 bits for max6695/96 */
316 	u8 max_convrate;	/* Maximum conversion rate */
317 	u8 reg_local_ext;	/* local extension register offset */
318 
319 	/* registers values */
320 	s8 temp8[8];	/* 0: local low limit
321 			 * 1: local high limit
322 			 * 2: local critical limit
323 			 * 3: remote critical limit
324 			 * 4: local emergency limit (max6659 and max6695/96)
325 			 * 5: remote emergency limit (max6659 and max6695/96)
326 			 * 6: remote 2 critical limit (max6695/96 only)
327 			 * 7: remote 2 emergency limit (max6695/96 only)
328 			 */
329 	s16 temp11[8];	/* 0: remote input
330 			 * 1: remote low limit
331 			 * 2: remote high limit
332 			 * 3: remote offset (except max6646, max6657/58/59,
333 			 *		     and max6695/96)
334 			 * 4: local input
335 			 * 5: remote 2 input (max6695/96 only)
336 			 * 6: remote 2 low limit (max6695/96 only)
337 			 * 7: remote 2 high limit (max6695/96 only)
338 			 */
339 	u8 temp_hyst;
340 	u16 alarms; /* bitvector (upper 8 bits for max6695/96) */
341 };
342 
343 /*
344  * Support functions
345  */
346 
347 /*
348  * The ADM1032 supports PEC but not on write byte transactions, so we need
349  * to explicitly ask for a transaction without PEC.
350  */
351 static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value)
352 {
353 	return i2c_smbus_xfer(client->adapter, client->addr,
354 			      client->flags & ~I2C_CLIENT_PEC,
355 			      I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
356 }
357 
358 /*
359  * It is assumed that client->update_lock is held (unless we are in
360  * detection or initialization steps). This matters when PEC is enabled,
361  * because we don't want the address pointer to change between the write
362  * byte and the read byte transactions.
363  */
364 static int lm90_read_reg(struct i2c_client *client, u8 reg, u8 *value)
365 {
366 	int err;
367 
368 	if (client->flags & I2C_CLIENT_PEC) {
369 		err = adm1032_write_byte(client, reg);
370 		if (err >= 0)
371 			err = i2c_smbus_read_byte(client);
372 	} else
373 		err = i2c_smbus_read_byte_data(client, reg);
374 
375 	if (err < 0) {
376 		dev_warn(&client->dev, "Register %#02x read failed (%d)\n",
377 			 reg, err);
378 		return err;
379 	}
380 	*value = err;
381 
382 	return 0;
383 }
384 
385 static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl, u16 *value)
386 {
387 	int err;
388 	u8 oldh, newh, l;
389 
390 	/*
391 	 * There is a trick here. We have to read two registers to have the
392 	 * sensor temperature, but we have to beware a conversion could occur
393 	 * between the readings. The datasheet says we should either use
394 	 * the one-shot conversion register, which we don't want to do
395 	 * (disables hardware monitoring) or monitor the busy bit, which is
396 	 * impossible (we can't read the values and monitor that bit at the
397 	 * exact same time). So the solution used here is to read the high
398 	 * byte once, then the low byte, then the high byte again. If the new
399 	 * high byte matches the old one, then we have a valid reading. Else
400 	 * we have to read the low byte again, and now we believe we have a
401 	 * correct reading.
402 	 */
403 	if ((err = lm90_read_reg(client, regh, &oldh))
404 	 || (err = lm90_read_reg(client, regl, &l))
405 	 || (err = lm90_read_reg(client, regh, &newh)))
406 		return err;
407 	if (oldh != newh) {
408 		err = lm90_read_reg(client, regl, &l);
409 		if (err)
410 			return err;
411 	}
412 	*value = (newh << 8) | l;
413 
414 	return 0;
415 }
416 
417 /*
418  * client->update_lock must be held when calling this function (unless we are
419  * in detection or initialization steps), and while a remote channel other
420  * than channel 0 is selected. Also, calling code must make sure to re-select
421  * external channel 0 before releasing the lock. This is necessary because
422  * various registers have different meanings as a result of selecting a
423  * non-default remote channel.
424  */
425 static inline void lm90_select_remote_channel(struct i2c_client *client,
426 					      struct lm90_data *data,
427 					      int channel)
428 {
429 	u8 config;
430 
431 	if (data->kind == max6696) {
432 		lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
433 		config &= ~0x08;
434 		if (channel)
435 			config |= 0x08;
436 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
437 					  config);
438 	}
439 }
440 
441 /*
442  * Set conversion rate.
443  * client->update_lock must be held when calling this function (unless we are
444  * in detection or initialization steps).
445  */
446 static void lm90_set_convrate(struct i2c_client *client, struct lm90_data *data,
447 			      unsigned int interval)
448 {
449 	int i;
450 	unsigned int update_interval;
451 
452 	/* Shift calculations to avoid rounding errors */
453 	interval <<= 6;
454 
455 	/* find the nearest update rate */
456 	for (i = 0, update_interval = LM90_MAX_CONVRATE_MS << 6;
457 	     i < data->max_convrate; i++, update_interval >>= 1)
458 		if (interval >= update_interval * 3 / 4)
459 			break;
460 
461 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, i);
462 	data->update_interval = DIV_ROUND_CLOSEST(update_interval, 64);
463 }
464 
465 static struct lm90_data *lm90_update_device(struct device *dev)
466 {
467 	struct i2c_client *client = to_i2c_client(dev);
468 	struct lm90_data *data = i2c_get_clientdata(client);
469 	unsigned long next_update;
470 
471 	mutex_lock(&data->update_lock);
472 
473 	next_update = data->last_updated +
474 		      msecs_to_jiffies(data->update_interval);
475 	if (time_after(jiffies, next_update) || !data->valid) {
476 		u8 h, l;
477 		u8 alarms;
478 
479 		dev_dbg(&client->dev, "Updating lm90 data.\n");
480 		lm90_read_reg(client, LM90_REG_R_LOCAL_LOW, &data->temp8[0]);
481 		lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH, &data->temp8[1]);
482 		lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT, &data->temp8[2]);
483 		lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[3]);
484 		lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
485 
486 		if (data->reg_local_ext) {
487 			lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
488 				    data->reg_local_ext,
489 				    &data->temp11[4]);
490 		} else {
491 			if (lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP,
492 					  &h) == 0)
493 				data->temp11[4] = h << 8;
494 		}
495 		lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
496 			    LM90_REG_R_REMOTE_TEMPL, &data->temp11[0]);
497 
498 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h) == 0) {
499 			data->temp11[1] = h << 8;
500 			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
501 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL,
502 					  &l) == 0)
503 				data->temp11[1] |= l;
504 		}
505 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h) == 0) {
506 			data->temp11[2] = h << 8;
507 			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
508 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL,
509 					  &l) == 0)
510 				data->temp11[2] |= l;
511 		}
512 
513 		if (data->flags & LM90_HAVE_OFFSET) {
514 			if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
515 					  &h) == 0
516 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,
517 					  &l) == 0)
518 				data->temp11[3] = (h << 8) | l;
519 		}
520 		if (data->flags & LM90_HAVE_EMERGENCY) {
521 			lm90_read_reg(client, MAX6659_REG_R_LOCAL_EMERG,
522 				      &data->temp8[4]);
523 			lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
524 				      &data->temp8[5]);
525 		}
526 		lm90_read_reg(client, LM90_REG_R_STATUS, &alarms);
527 		data->alarms = alarms;	/* save as 16 bit value */
528 
529 		if (data->kind == max6696) {
530 			lm90_select_remote_channel(client, data, 1);
531 			lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT,
532 				      &data->temp8[6]);
533 			lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
534 				      &data->temp8[7]);
535 			lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
536 				    LM90_REG_R_REMOTE_TEMPL, &data->temp11[5]);
537 			if (!lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h))
538 				data->temp11[6] = h << 8;
539 			if (!lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h))
540 				data->temp11[7] = h << 8;
541 			lm90_select_remote_channel(client, data, 0);
542 
543 			if (!lm90_read_reg(client, MAX6696_REG_R_STATUS2,
544 					   &alarms))
545 				data->alarms |= alarms << 8;
546 		}
547 
548 		/*
549 		 * Re-enable ALERT# output if it was originally enabled and
550 		 * relevant alarms are all clear
551 		 */
552 		if ((data->config_orig & 0x80) == 0
553 		 && (data->alarms & data->alert_alarms) == 0) {
554 			u8 config;
555 
556 			lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
557 			if (config & 0x80) {
558 				dev_dbg(&client->dev, "Re-enabling ALERT#\n");
559 				i2c_smbus_write_byte_data(client,
560 							  LM90_REG_W_CONFIG1,
561 							  config & ~0x80);
562 			}
563 		}
564 
565 		data->last_updated = jiffies;
566 		data->valid = 1;
567 	}
568 
569 	mutex_unlock(&data->update_lock);
570 
571 	return data;
572 }
573 
574 /*
575  * Conversions
576  * For local temperatures and limits, critical limits and the hysteresis
577  * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
578  * For remote temperatures and limits, it uses signed 11-bit values with
579  * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.  Some
580  * Maxim chips use unsigned values.
581  */
582 
583 static inline int temp_from_s8(s8 val)
584 {
585 	return val * 1000;
586 }
587 
588 static inline int temp_from_u8(u8 val)
589 {
590 	return val * 1000;
591 }
592 
593 static inline int temp_from_s16(s16 val)
594 {
595 	return val / 32 * 125;
596 }
597 
598 static inline int temp_from_u16(u16 val)
599 {
600 	return val / 32 * 125;
601 }
602 
603 static s8 temp_to_s8(long val)
604 {
605 	if (val <= -128000)
606 		return -128;
607 	if (val >= 127000)
608 		return 127;
609 	if (val < 0)
610 		return (val - 500) / 1000;
611 	return (val + 500) / 1000;
612 }
613 
614 static u8 temp_to_u8(long val)
615 {
616 	if (val <= 0)
617 		return 0;
618 	if (val >= 255000)
619 		return 255;
620 	return (val + 500) / 1000;
621 }
622 
623 static s16 temp_to_s16(long val)
624 {
625 	if (val <= -128000)
626 		return 0x8000;
627 	if (val >= 127875)
628 		return 0x7FE0;
629 	if (val < 0)
630 		return (val - 62) / 125 * 32;
631 	return (val + 62) / 125 * 32;
632 }
633 
634 static u8 hyst_to_reg(long val)
635 {
636 	if (val <= 0)
637 		return 0;
638 	if (val >= 30500)
639 		return 31;
640 	return (val + 500) / 1000;
641 }
642 
643 /*
644  * ADT7461 in compatibility mode is almost identical to LM90 except that
645  * attempts to write values that are outside the range 0 < temp < 127 are
646  * treated as the boundary value.
647  *
648  * ADT7461 in "extended mode" operation uses unsigned integers offset by
649  * 64 (e.g., 0 -> -64 degC).  The range is restricted to -64..191 degC.
650  */
651 static inline int temp_from_u8_adt7461(struct lm90_data *data, u8 val)
652 {
653 	if (data->flags & LM90_FLAG_ADT7461_EXT)
654 		return (val - 64) * 1000;
655 	else
656 		return temp_from_s8(val);
657 }
658 
659 static inline int temp_from_u16_adt7461(struct lm90_data *data, u16 val)
660 {
661 	if (data->flags & LM90_FLAG_ADT7461_EXT)
662 		return (val - 0x4000) / 64 * 250;
663 	else
664 		return temp_from_s16(val);
665 }
666 
667 static u8 temp_to_u8_adt7461(struct lm90_data *data, long val)
668 {
669 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
670 		if (val <= -64000)
671 			return 0;
672 		if (val >= 191000)
673 			return 0xFF;
674 		return (val + 500 + 64000) / 1000;
675 	} else {
676 		if (val <= 0)
677 			return 0;
678 		if (val >= 127000)
679 			return 127;
680 		return (val + 500) / 1000;
681 	}
682 }
683 
684 static u16 temp_to_u16_adt7461(struct lm90_data *data, long val)
685 {
686 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
687 		if (val <= -64000)
688 			return 0;
689 		if (val >= 191750)
690 			return 0xFFC0;
691 		return (val + 64000 + 125) / 250 * 64;
692 	} else {
693 		if (val <= 0)
694 			return 0;
695 		if (val >= 127750)
696 			return 0x7FC0;
697 		return (val + 125) / 250 * 64;
698 	}
699 }
700 
701 /*
702  * Sysfs stuff
703  */
704 
705 static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
706 			  char *buf)
707 {
708 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
709 	struct lm90_data *data = lm90_update_device(dev);
710 	int temp;
711 
712 	if (data->kind == adt7461)
713 		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
714 	else if (data->kind == max6646)
715 		temp = temp_from_u8(data->temp8[attr->index]);
716 	else
717 		temp = temp_from_s8(data->temp8[attr->index]);
718 
719 	/* +16 degrees offset for temp2 for the LM99 */
720 	if (data->kind == lm99 && attr->index == 3)
721 		temp += 16000;
722 
723 	return sprintf(buf, "%d\n", temp);
724 }
725 
726 static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
727 			 const char *buf, size_t count)
728 {
729 	static const u8 reg[8] = {
730 		LM90_REG_W_LOCAL_LOW,
731 		LM90_REG_W_LOCAL_HIGH,
732 		LM90_REG_W_LOCAL_CRIT,
733 		LM90_REG_W_REMOTE_CRIT,
734 		MAX6659_REG_W_LOCAL_EMERG,
735 		MAX6659_REG_W_REMOTE_EMERG,
736 		LM90_REG_W_REMOTE_CRIT,
737 		MAX6659_REG_W_REMOTE_EMERG,
738 	};
739 
740 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
741 	struct i2c_client *client = to_i2c_client(dev);
742 	struct lm90_data *data = i2c_get_clientdata(client);
743 	int nr = attr->index;
744 	long val;
745 	int err;
746 
747 	err = kstrtol(buf, 10, &val);
748 	if (err < 0)
749 		return err;
750 
751 	/* +16 degrees offset for temp2 for the LM99 */
752 	if (data->kind == lm99 && attr->index == 3)
753 		val -= 16000;
754 
755 	mutex_lock(&data->update_lock);
756 	if (data->kind == adt7461)
757 		data->temp8[nr] = temp_to_u8_adt7461(data, val);
758 	else if (data->kind == max6646)
759 		data->temp8[nr] = temp_to_u8(val);
760 	else
761 		data->temp8[nr] = temp_to_s8(val);
762 
763 	lm90_select_remote_channel(client, data, nr >= 6);
764 	i2c_smbus_write_byte_data(client, reg[nr], data->temp8[nr]);
765 	lm90_select_remote_channel(client, data, 0);
766 
767 	mutex_unlock(&data->update_lock);
768 	return count;
769 }
770 
771 static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
772 			   char *buf)
773 {
774 	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
775 	struct lm90_data *data = lm90_update_device(dev);
776 	int temp;
777 
778 	if (data->kind == adt7461)
779 		temp = temp_from_u16_adt7461(data, data->temp11[attr->index]);
780 	else if (data->kind == max6646)
781 		temp = temp_from_u16(data->temp11[attr->index]);
782 	else
783 		temp = temp_from_s16(data->temp11[attr->index]);
784 
785 	/* +16 degrees offset for temp2 for the LM99 */
786 	if (data->kind == lm99 &&  attr->index <= 2)
787 		temp += 16000;
788 
789 	return sprintf(buf, "%d\n", temp);
790 }
791 
792 static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
793 			  const char *buf, size_t count)
794 {
795 	struct {
796 		u8 high;
797 		u8 low;
798 		int channel;
799 	} reg[5] = {
800 		{ LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL, 0 },
801 		{ LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 0 },
802 		{ LM90_REG_W_REMOTE_OFFSH, LM90_REG_W_REMOTE_OFFSL, 0 },
803 		{ LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL, 1 },
804 		{ LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 1 }
805 	};
806 
807 	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
808 	struct i2c_client *client = to_i2c_client(dev);
809 	struct lm90_data *data = i2c_get_clientdata(client);
810 	int nr = attr->nr;
811 	int index = attr->index;
812 	long val;
813 	int err;
814 
815 	err = kstrtol(buf, 10, &val);
816 	if (err < 0)
817 		return err;
818 
819 	/* +16 degrees offset for temp2 for the LM99 */
820 	if (data->kind == lm99 && index <= 2)
821 		val -= 16000;
822 
823 	mutex_lock(&data->update_lock);
824 	if (data->kind == adt7461)
825 		data->temp11[index] = temp_to_u16_adt7461(data, val);
826 	else if (data->kind == max6646)
827 		data->temp11[index] = temp_to_u8(val) << 8;
828 	else if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
829 		data->temp11[index] = temp_to_s16(val);
830 	else
831 		data->temp11[index] = temp_to_s8(val) << 8;
832 
833 	lm90_select_remote_channel(client, data, reg[nr].channel);
834 	i2c_smbus_write_byte_data(client, reg[nr].high,
835 				  data->temp11[index] >> 8);
836 	if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
837 		i2c_smbus_write_byte_data(client, reg[nr].low,
838 					  data->temp11[index] & 0xff);
839 	lm90_select_remote_channel(client, data, 0);
840 
841 	mutex_unlock(&data->update_lock);
842 	return count;
843 }
844 
845 static ssize_t show_temphyst(struct device *dev,
846 			     struct device_attribute *devattr,
847 			     char *buf)
848 {
849 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
850 	struct lm90_data *data = lm90_update_device(dev);
851 	int temp;
852 
853 	if (data->kind == adt7461)
854 		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
855 	else if (data->kind == max6646)
856 		temp = temp_from_u8(data->temp8[attr->index]);
857 	else
858 		temp = temp_from_s8(data->temp8[attr->index]);
859 
860 	/* +16 degrees offset for temp2 for the LM99 */
861 	if (data->kind == lm99 && attr->index == 3)
862 		temp += 16000;
863 
864 	return sprintf(buf, "%d\n", temp - temp_from_s8(data->temp_hyst));
865 }
866 
867 static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
868 			    const char *buf, size_t count)
869 {
870 	struct i2c_client *client = to_i2c_client(dev);
871 	struct lm90_data *data = i2c_get_clientdata(client);
872 	long val;
873 	int err;
874 	int temp;
875 
876 	err = kstrtol(buf, 10, &val);
877 	if (err < 0)
878 		return err;
879 
880 	mutex_lock(&data->update_lock);
881 	if (data->kind == adt7461)
882 		temp = temp_from_u8_adt7461(data, data->temp8[2]);
883 	else if (data->kind == max6646)
884 		temp = temp_from_u8(data->temp8[2]);
885 	else
886 		temp = temp_from_s8(data->temp8[2]);
887 
888 	data->temp_hyst = hyst_to_reg(temp - val);
889 	i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
890 				  data->temp_hyst);
891 	mutex_unlock(&data->update_lock);
892 	return count;
893 }
894 
895 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
896 			   char *buf)
897 {
898 	struct lm90_data *data = lm90_update_device(dev);
899 	return sprintf(buf, "%d\n", data->alarms);
900 }
901 
902 static ssize_t show_alarm(struct device *dev, struct device_attribute
903 			  *devattr, char *buf)
904 {
905 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
906 	struct lm90_data *data = lm90_update_device(dev);
907 	int bitnr = attr->index;
908 
909 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
910 }
911 
912 static ssize_t show_update_interval(struct device *dev,
913 				    struct device_attribute *attr, char *buf)
914 {
915 	struct lm90_data *data = dev_get_drvdata(dev);
916 
917 	return sprintf(buf, "%u\n", data->update_interval);
918 }
919 
920 static ssize_t set_update_interval(struct device *dev,
921 				   struct device_attribute *attr,
922 				   const char *buf, size_t count)
923 {
924 	struct i2c_client *client = to_i2c_client(dev);
925 	struct lm90_data *data = i2c_get_clientdata(client);
926 	unsigned long val;
927 	int err;
928 
929 	err = kstrtoul(buf, 10, &val);
930 	if (err)
931 		return err;
932 
933 	mutex_lock(&data->update_lock);
934 	lm90_set_convrate(client, data, clamp_val(val, 0, 100000));
935 	mutex_unlock(&data->update_lock);
936 
937 	return count;
938 }
939 
940 static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp11, NULL, 0, 4);
941 static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp11, NULL, 0, 0);
942 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
943 	set_temp8, 0);
944 static SENSOR_DEVICE_ATTR_2(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
945 	set_temp11, 0, 1);
946 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
947 	set_temp8, 1);
948 static SENSOR_DEVICE_ATTR_2(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
949 	set_temp11, 1, 2);
950 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
951 	set_temp8, 2);
952 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
953 	set_temp8, 3);
954 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
955 	set_temphyst, 2);
956 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 3);
957 static SENSOR_DEVICE_ATTR_2(temp2_offset, S_IWUSR | S_IRUGO, show_temp11,
958 	set_temp11, 2, 3);
959 
960 /* Individual alarm files */
961 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
962 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
963 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
964 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
965 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
966 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 5);
967 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
968 /* Raw alarm file for compatibility */
969 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
970 
971 static DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR, show_update_interval,
972 		   set_update_interval);
973 
974 static struct attribute *lm90_attributes[] = {
975 	&sensor_dev_attr_temp1_input.dev_attr.attr,
976 	&sensor_dev_attr_temp2_input.dev_attr.attr,
977 	&sensor_dev_attr_temp1_min.dev_attr.attr,
978 	&sensor_dev_attr_temp2_min.dev_attr.attr,
979 	&sensor_dev_attr_temp1_max.dev_attr.attr,
980 	&sensor_dev_attr_temp2_max.dev_attr.attr,
981 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
982 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
983 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
984 	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
985 
986 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
987 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
988 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
989 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
990 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
991 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
992 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
993 	&dev_attr_alarms.attr,
994 	&dev_attr_update_interval.attr,
995 	NULL
996 };
997 
998 static const struct attribute_group lm90_group = {
999 	.attrs = lm90_attributes,
1000 };
1001 
1002 /*
1003  * Additional attributes for devices with emergency sensors
1004  */
1005 static SENSOR_DEVICE_ATTR(temp1_emergency, S_IWUSR | S_IRUGO, show_temp8,
1006 	set_temp8, 4);
1007 static SENSOR_DEVICE_ATTR(temp2_emergency, S_IWUSR | S_IRUGO, show_temp8,
1008 	set_temp8, 5);
1009 static SENSOR_DEVICE_ATTR(temp1_emergency_hyst, S_IRUGO, show_temphyst,
1010 			  NULL, 4);
1011 static SENSOR_DEVICE_ATTR(temp2_emergency_hyst, S_IRUGO, show_temphyst,
1012 			  NULL, 5);
1013 
1014 static struct attribute *lm90_emergency_attributes[] = {
1015 	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
1016 	&sensor_dev_attr_temp2_emergency.dev_attr.attr,
1017 	&sensor_dev_attr_temp1_emergency_hyst.dev_attr.attr,
1018 	&sensor_dev_attr_temp2_emergency_hyst.dev_attr.attr,
1019 	NULL
1020 };
1021 
1022 static const struct attribute_group lm90_emergency_group = {
1023 	.attrs = lm90_emergency_attributes,
1024 };
1025 
1026 static SENSOR_DEVICE_ATTR(temp1_emergency_alarm, S_IRUGO, show_alarm, NULL, 15);
1027 static SENSOR_DEVICE_ATTR(temp2_emergency_alarm, S_IRUGO, show_alarm, NULL, 13);
1028 
1029 static struct attribute *lm90_emergency_alarm_attributes[] = {
1030 	&sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
1031 	&sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
1032 	NULL
1033 };
1034 
1035 static const struct attribute_group lm90_emergency_alarm_group = {
1036 	.attrs = lm90_emergency_alarm_attributes,
1037 };
1038 
1039 /*
1040  * Additional attributes for devices with 3 temperature sensors
1041  */
1042 static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp11, NULL, 0, 5);
1043 static SENSOR_DEVICE_ATTR_2(temp3_min, S_IWUSR | S_IRUGO, show_temp11,
1044 	set_temp11, 3, 6);
1045 static SENSOR_DEVICE_ATTR_2(temp3_max, S_IWUSR | S_IRUGO, show_temp11,
1046 	set_temp11, 4, 7);
1047 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp8,
1048 	set_temp8, 6);
1049 static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO, show_temphyst, NULL, 6);
1050 static SENSOR_DEVICE_ATTR(temp3_emergency, S_IWUSR | S_IRUGO, show_temp8,
1051 	set_temp8, 7);
1052 static SENSOR_DEVICE_ATTR(temp3_emergency_hyst, S_IRUGO, show_temphyst,
1053 			  NULL, 7);
1054 
1055 static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
1056 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 10);
1057 static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_alarm, NULL, 11);
1058 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 12);
1059 static SENSOR_DEVICE_ATTR(temp3_emergency_alarm, S_IRUGO, show_alarm, NULL, 14);
1060 
1061 static struct attribute *lm90_temp3_attributes[] = {
1062 	&sensor_dev_attr_temp3_input.dev_attr.attr,
1063 	&sensor_dev_attr_temp3_min.dev_attr.attr,
1064 	&sensor_dev_attr_temp3_max.dev_attr.attr,
1065 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
1066 	&sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
1067 	&sensor_dev_attr_temp3_emergency.dev_attr.attr,
1068 	&sensor_dev_attr_temp3_emergency_hyst.dev_attr.attr,
1069 
1070 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
1071 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
1072 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
1073 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
1074 	&sensor_dev_attr_temp3_emergency_alarm.dev_attr.attr,
1075 	NULL
1076 };
1077 
1078 static const struct attribute_group lm90_temp3_group = {
1079 	.attrs = lm90_temp3_attributes,
1080 };
1081 
1082 /* pec used for ADM1032 only */
1083 static ssize_t show_pec(struct device *dev, struct device_attribute *dummy,
1084 			char *buf)
1085 {
1086 	struct i2c_client *client = to_i2c_client(dev);
1087 	return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
1088 }
1089 
1090 static ssize_t set_pec(struct device *dev, struct device_attribute *dummy,
1091 		       const char *buf, size_t count)
1092 {
1093 	struct i2c_client *client = to_i2c_client(dev);
1094 	long val;
1095 	int err;
1096 
1097 	err = kstrtol(buf, 10, &val);
1098 	if (err < 0)
1099 		return err;
1100 
1101 	switch (val) {
1102 	case 0:
1103 		client->flags &= ~I2C_CLIENT_PEC;
1104 		break;
1105 	case 1:
1106 		client->flags |= I2C_CLIENT_PEC;
1107 		break;
1108 	default:
1109 		return -EINVAL;
1110 	}
1111 
1112 	return count;
1113 }
1114 
1115 static DEVICE_ATTR(pec, S_IWUSR | S_IRUGO, show_pec, set_pec);
1116 
1117 /*
1118  * Real code
1119  */
1120 
1121 /* Return 0 if detection is successful, -ENODEV otherwise */
1122 static int lm90_detect(struct i2c_client *client,
1123 		       struct i2c_board_info *info)
1124 {
1125 	struct i2c_adapter *adapter = client->adapter;
1126 	int address = client->addr;
1127 	const char *name = NULL;
1128 	int man_id, chip_id, config1, config2, convrate;
1129 
1130 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
1131 		return -ENODEV;
1132 
1133 	/* detection and identification */
1134 	man_id = i2c_smbus_read_byte_data(client, LM90_REG_R_MAN_ID);
1135 	chip_id = i2c_smbus_read_byte_data(client, LM90_REG_R_CHIP_ID);
1136 	config1 = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG1);
1137 	convrate = i2c_smbus_read_byte_data(client, LM90_REG_R_CONVRATE);
1138 	if (man_id < 0 || chip_id < 0 || config1 < 0 || convrate < 0)
1139 		return -ENODEV;
1140 
1141 	if (man_id == 0x01 || man_id == 0x5C || man_id == 0x41) {
1142 		config2 = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG2);
1143 		if (config2 < 0)
1144 			return -ENODEV;
1145 	} else
1146 		config2 = 0;		/* Make compiler happy */
1147 
1148 	if ((address == 0x4C || address == 0x4D)
1149 	 && man_id == 0x01) { /* National Semiconductor */
1150 		if ((config1 & 0x2A) == 0x00
1151 		 && (config2 & 0xF8) == 0x00
1152 		 && convrate <= 0x09) {
1153 			if (address == 0x4C
1154 			 && (chip_id & 0xF0) == 0x20) { /* LM90 */
1155 				name = "lm90";
1156 			} else
1157 			if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
1158 				name = "lm99";
1159 				dev_info(&adapter->dev,
1160 					 "Assuming LM99 chip at 0x%02x\n",
1161 					 address);
1162 				dev_info(&adapter->dev,
1163 					 "If it is an LM89, instantiate it "
1164 					 "with the new_device sysfs "
1165 					 "interface\n");
1166 			} else
1167 			if (address == 0x4C
1168 			 && (chip_id & 0xF0) == 0x10) { /* LM86 */
1169 				name = "lm86";
1170 			}
1171 		}
1172 	} else
1173 	if ((address == 0x4C || address == 0x4D)
1174 	 && man_id == 0x41) { /* Analog Devices */
1175 		if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
1176 		 && (config1 & 0x3F) == 0x00
1177 		 && convrate <= 0x0A) {
1178 			name = "adm1032";
1179 			/*
1180 			 * The ADM1032 supports PEC, but only if combined
1181 			 * transactions are not used.
1182 			 */
1183 			if (i2c_check_functionality(adapter,
1184 						    I2C_FUNC_SMBUS_BYTE))
1185 				info->flags |= I2C_CLIENT_PEC;
1186 		} else
1187 		if (chip_id == 0x51 /* ADT7461 */
1188 		 && (config1 & 0x1B) == 0x00
1189 		 && convrate <= 0x0A) {
1190 			name = "adt7461";
1191 		} else
1192 		if (chip_id == 0x57 /* ADT7461A, NCT1008 */
1193 		 && (config1 & 0x1B) == 0x00
1194 		 && convrate <= 0x0A) {
1195 			name = "adt7461a";
1196 		}
1197 	} else
1198 	if (man_id == 0x4D) { /* Maxim */
1199 		int emerg, emerg2, status2;
1200 
1201 		/*
1202 		 * We read MAX6659_REG_R_REMOTE_EMERG twice, and re-read
1203 		 * LM90_REG_R_MAN_ID in between. If MAX6659_REG_R_REMOTE_EMERG
1204 		 * exists, both readings will reflect the same value. Otherwise,
1205 		 * the readings will be different.
1206 		 */
1207 		emerg = i2c_smbus_read_byte_data(client,
1208 						 MAX6659_REG_R_REMOTE_EMERG);
1209 		man_id = i2c_smbus_read_byte_data(client,
1210 						  LM90_REG_R_MAN_ID);
1211 		emerg2 = i2c_smbus_read_byte_data(client,
1212 						  MAX6659_REG_R_REMOTE_EMERG);
1213 		status2 = i2c_smbus_read_byte_data(client,
1214 						   MAX6696_REG_R_STATUS2);
1215 		if (emerg < 0 || man_id < 0 || emerg2 < 0 || status2 < 0)
1216 			return -ENODEV;
1217 
1218 		/*
1219 		 * The MAX6657, MAX6658 and MAX6659 do NOT have a chip_id
1220 		 * register. Reading from that address will return the last
1221 		 * read value, which in our case is those of the man_id
1222 		 * register. Likewise, the config1 register seems to lack a
1223 		 * low nibble, so the value will be those of the previous
1224 		 * read, so in our case those of the man_id register.
1225 		 * MAX6659 has a third set of upper temperature limit registers.
1226 		 * Those registers also return values on MAX6657 and MAX6658,
1227 		 * thus the only way to detect MAX6659 is by its address.
1228 		 * For this reason it will be mis-detected as MAX6657 if its
1229 		 * address is 0x4C.
1230 		 */
1231 		if (chip_id == man_id
1232 		 && (address == 0x4C || address == 0x4D || address == 0x4E)
1233 		 && (config1 & 0x1F) == (man_id & 0x0F)
1234 		 && convrate <= 0x09) {
1235 			if (address == 0x4C)
1236 				name = "max6657";
1237 			else
1238 				name = "max6659";
1239 		} else
1240 		/*
1241 		 * Even though MAX6695 and MAX6696 do not have a chip ID
1242 		 * register, reading it returns 0x01. Bit 4 of the config1
1243 		 * register is unused and should return zero when read. Bit 0 of
1244 		 * the status2 register is unused and should return zero when
1245 		 * read.
1246 		 *
1247 		 * MAX6695 and MAX6696 have an additional set of temperature
1248 		 * limit registers. We can detect those chips by checking if
1249 		 * one of those registers exists.
1250 		 */
1251 		if (chip_id == 0x01
1252 		 && (config1 & 0x10) == 0x00
1253 		 && (status2 & 0x01) == 0x00
1254 		 && emerg == emerg2
1255 		 && convrate <= 0x07) {
1256 			name = "max6696";
1257 		} else
1258 		/*
1259 		 * The chip_id register of the MAX6680 and MAX6681 holds the
1260 		 * revision of the chip. The lowest bit of the config1 register
1261 		 * is unused and should return zero when read, so should the
1262 		 * second to last bit of config1 (software reset).
1263 		 */
1264 		if (chip_id == 0x01
1265 		 && (config1 & 0x03) == 0x00
1266 		 && convrate <= 0x07) {
1267 			name = "max6680";
1268 		} else
1269 		/*
1270 		 * The chip_id register of the MAX6646/6647/6649 holds the
1271 		 * revision of the chip. The lowest 6 bits of the config1
1272 		 * register are unused and should return zero when read.
1273 		 */
1274 		if (chip_id == 0x59
1275 		 && (config1 & 0x3f) == 0x00
1276 		 && convrate <= 0x07) {
1277 			name = "max6646";
1278 		}
1279 	} else
1280 	if (address == 0x4C
1281 	 && man_id == 0x5C) { /* Winbond/Nuvoton */
1282 		if ((config1 & 0x2A) == 0x00
1283 		 && (config2 & 0xF8) == 0x00) {
1284 			if (chip_id == 0x01 /* W83L771W/G */
1285 			 && convrate <= 0x09) {
1286 				name = "w83l771";
1287 			} else
1288 			if ((chip_id & 0xFE) == 0x10 /* W83L771AWG/ASG */
1289 			 && convrate <= 0x08) {
1290 				name = "w83l771";
1291 			}
1292 		}
1293 	} else
1294 	if (address >= 0x48 && address <= 0x4F
1295 	 && man_id == 0xA1) { /*  NXP Semiconductor/Philips */
1296 		if (chip_id == 0x00
1297 		 && (config1 & 0x2A) == 0x00
1298 		 && (config2 & 0xFE) == 0x00
1299 		 && convrate <= 0x09) {
1300 			name = "sa56004";
1301 		}
1302 	} else
1303 	if ((address == 0x4C || address == 0x4D)
1304 	 && man_id == 0x47) { /* GMT */
1305 		if (chip_id == 0x01 /* G781 */
1306 		 && (config1 & 0x3F) == 0x00
1307 		 && convrate <= 0x08)
1308 			name = "g781";
1309 	}
1310 
1311 	if (!name) { /* identification failed */
1312 		dev_dbg(&adapter->dev,
1313 			"Unsupported chip at 0x%02x (man_id=0x%02X, "
1314 			"chip_id=0x%02X)\n", address, man_id, chip_id);
1315 		return -ENODEV;
1316 	}
1317 
1318 	strlcpy(info->type, name, I2C_NAME_SIZE);
1319 
1320 	return 0;
1321 }
1322 
1323 static void lm90_remove_files(struct i2c_client *client, struct lm90_data *data)
1324 {
1325 	struct device *dev = &client->dev;
1326 
1327 	if (data->flags & LM90_HAVE_TEMP3)
1328 		sysfs_remove_group(&dev->kobj, &lm90_temp3_group);
1329 	if (data->flags & LM90_HAVE_EMERGENCY_ALARM)
1330 		sysfs_remove_group(&dev->kobj, &lm90_emergency_alarm_group);
1331 	if (data->flags & LM90_HAVE_EMERGENCY)
1332 		sysfs_remove_group(&dev->kobj, &lm90_emergency_group);
1333 	if (data->flags & LM90_HAVE_OFFSET)
1334 		device_remove_file(dev, &sensor_dev_attr_temp2_offset.dev_attr);
1335 	device_remove_file(dev, &dev_attr_pec);
1336 	sysfs_remove_group(&dev->kobj, &lm90_group);
1337 }
1338 
1339 static void lm90_restore_conf(struct i2c_client *client, struct lm90_data *data)
1340 {
1341 	/* Restore initial configuration */
1342 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
1343 				  data->convrate_orig);
1344 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
1345 				  data->config_orig);
1346 }
1347 
1348 static void lm90_init_client(struct i2c_client *client)
1349 {
1350 	u8 config, convrate;
1351 	struct lm90_data *data = i2c_get_clientdata(client);
1352 
1353 	if (lm90_read_reg(client, LM90_REG_R_CONVRATE, &convrate) < 0) {
1354 		dev_warn(&client->dev, "Failed to read convrate register!\n");
1355 		convrate = LM90_DEF_CONVRATE_RVAL;
1356 	}
1357 	data->convrate_orig = convrate;
1358 
1359 	/*
1360 	 * Start the conversions.
1361 	 */
1362 	lm90_set_convrate(client, data, 500);	/* 500ms; 2Hz conversion rate */
1363 	if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) {
1364 		dev_warn(&client->dev, "Initialization failed!\n");
1365 		return;
1366 	}
1367 	data->config_orig = config;
1368 
1369 	/* Check Temperature Range Select */
1370 	if (data->kind == adt7461) {
1371 		if (config & 0x04)
1372 			data->flags |= LM90_FLAG_ADT7461_EXT;
1373 	}
1374 
1375 	/*
1376 	 * Put MAX6680/MAX8881 into extended resolution (bit 0x10,
1377 	 * 0.125 degree resolution) and range (0x08, extend range
1378 	 * to -64 degree) mode for the remote temperature sensor.
1379 	 */
1380 	if (data->kind == max6680)
1381 		config |= 0x18;
1382 
1383 	/*
1384 	 * Select external channel 0 for max6695/96
1385 	 */
1386 	if (data->kind == max6696)
1387 		config &= ~0x08;
1388 
1389 	config &= 0xBF;	/* run */
1390 	if (config != data->config_orig) /* Only write if changed */
1391 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config);
1392 }
1393 
1394 static int lm90_probe(struct i2c_client *client,
1395 		      const struct i2c_device_id *id)
1396 {
1397 	struct device *dev = &client->dev;
1398 	struct i2c_adapter *adapter = to_i2c_adapter(dev->parent);
1399 	struct lm90_data *data;
1400 	int err;
1401 
1402 	data = devm_kzalloc(&client->dev, sizeof(struct lm90_data), GFP_KERNEL);
1403 	if (!data)
1404 		return -ENOMEM;
1405 
1406 	i2c_set_clientdata(client, data);
1407 	mutex_init(&data->update_lock);
1408 
1409 	/* Set the device type */
1410 	data->kind = id->driver_data;
1411 	if (data->kind == adm1032) {
1412 		if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
1413 			client->flags &= ~I2C_CLIENT_PEC;
1414 	}
1415 
1416 	/*
1417 	 * Different devices have different alarm bits triggering the
1418 	 * ALERT# output
1419 	 */
1420 	data->alert_alarms = lm90_params[data->kind].alert_alarms;
1421 
1422 	/* Set chip capabilities */
1423 	data->flags = lm90_params[data->kind].flags;
1424 	data->reg_local_ext = lm90_params[data->kind].reg_local_ext;
1425 
1426 	/* Set maximum conversion rate */
1427 	data->max_convrate = lm90_params[data->kind].max_convrate;
1428 
1429 	/* Initialize the LM90 chip */
1430 	lm90_init_client(client);
1431 
1432 	/* Register sysfs hooks */
1433 	err = sysfs_create_group(&dev->kobj, &lm90_group);
1434 	if (err)
1435 		goto exit_restore;
1436 	if (client->flags & I2C_CLIENT_PEC) {
1437 		err = device_create_file(dev, &dev_attr_pec);
1438 		if (err)
1439 			goto exit_remove_files;
1440 	}
1441 	if (data->flags & LM90_HAVE_OFFSET) {
1442 		err = device_create_file(dev,
1443 					&sensor_dev_attr_temp2_offset.dev_attr);
1444 		if (err)
1445 			goto exit_remove_files;
1446 	}
1447 	if (data->flags & LM90_HAVE_EMERGENCY) {
1448 		err = sysfs_create_group(&dev->kobj, &lm90_emergency_group);
1449 		if (err)
1450 			goto exit_remove_files;
1451 	}
1452 	if (data->flags & LM90_HAVE_EMERGENCY_ALARM) {
1453 		err = sysfs_create_group(&dev->kobj,
1454 					 &lm90_emergency_alarm_group);
1455 		if (err)
1456 			goto exit_remove_files;
1457 	}
1458 	if (data->flags & LM90_HAVE_TEMP3) {
1459 		err = sysfs_create_group(&dev->kobj, &lm90_temp3_group);
1460 		if (err)
1461 			goto exit_remove_files;
1462 	}
1463 
1464 	data->hwmon_dev = hwmon_device_register(dev);
1465 	if (IS_ERR(data->hwmon_dev)) {
1466 		err = PTR_ERR(data->hwmon_dev);
1467 		goto exit_remove_files;
1468 	}
1469 
1470 	return 0;
1471 
1472 exit_remove_files:
1473 	lm90_remove_files(client, data);
1474 exit_restore:
1475 	lm90_restore_conf(client, data);
1476 	return err;
1477 }
1478 
1479 static int lm90_remove(struct i2c_client *client)
1480 {
1481 	struct lm90_data *data = i2c_get_clientdata(client);
1482 
1483 	hwmon_device_unregister(data->hwmon_dev);
1484 	lm90_remove_files(client, data);
1485 	lm90_restore_conf(client, data);
1486 
1487 	return 0;
1488 }
1489 
1490 static void lm90_alert(struct i2c_client *client, unsigned int flag)
1491 {
1492 	struct lm90_data *data = i2c_get_clientdata(client);
1493 	u8 config, alarms, alarms2 = 0;
1494 
1495 	lm90_read_reg(client, LM90_REG_R_STATUS, &alarms);
1496 
1497 	if (data->kind == max6696)
1498 		lm90_read_reg(client, MAX6696_REG_R_STATUS2, &alarms2);
1499 
1500 	if ((alarms & 0x7f) == 0 && (alarms2 & 0xfe) == 0) {
1501 		dev_info(&client->dev, "Everything OK\n");
1502 	} else {
1503 		if (alarms & 0x61)
1504 			dev_warn(&client->dev,
1505 				 "temp%d out of range, please check!\n", 1);
1506 		if (alarms & 0x1a)
1507 			dev_warn(&client->dev,
1508 				 "temp%d out of range, please check!\n", 2);
1509 		if (alarms & 0x04)
1510 			dev_warn(&client->dev,
1511 				 "temp%d diode open, please check!\n", 2);
1512 
1513 		if (alarms2 & 0x18)
1514 			dev_warn(&client->dev,
1515 				 "temp%d out of range, please check!\n", 3);
1516 
1517 		/*
1518 		 * Disable ALERT# output, because these chips don't implement
1519 		 * SMBus alert correctly; they should only hold the alert line
1520 		 * low briefly.
1521 		 */
1522 		if ((data->flags & LM90_HAVE_BROKEN_ALERT)
1523 		 && (alarms & data->alert_alarms)) {
1524 			dev_dbg(&client->dev, "Disabling ALERT#\n");
1525 			lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
1526 			i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
1527 						  config | 0x80);
1528 		}
1529 	}
1530 }
1531 
1532 static struct i2c_driver lm90_driver = {
1533 	.class		= I2C_CLASS_HWMON,
1534 	.driver = {
1535 		.name	= "lm90",
1536 	},
1537 	.probe		= lm90_probe,
1538 	.remove		= lm90_remove,
1539 	.alert		= lm90_alert,
1540 	.id_table	= lm90_id,
1541 	.detect		= lm90_detect,
1542 	.address_list	= normal_i2c,
1543 };
1544 
1545 module_i2c_driver(lm90_driver);
1546 
1547 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
1548 MODULE_DESCRIPTION("LM90/ADM1032 driver");
1549 MODULE_LICENSE("GPL");
1550