xref: /openbmc/linux/drivers/hwmon/lm90.c (revision 7fe2f639)
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  * Since the LM90 was the first chipset supported by this driver, most
58  * comments will refer to this chipset, but are actually general and
59  * concern all supported chipsets, unless mentioned otherwise.
60  *
61  * This program is free software; you can redistribute it and/or modify
62  * it under the terms of the GNU General Public License as published by
63  * the Free Software Foundation; either version 2 of the License, or
64  * (at your option) any later version.
65  *
66  * This program is distributed in the hope that it will be useful,
67  * but WITHOUT ANY WARRANTY; without even the implied warranty of
68  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
69  * GNU General Public License for more details.
70  *
71  * You should have received a copy of the GNU General Public License
72  * along with this program; if not, write to the Free Software
73  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
74  */
75 
76 #include <linux/module.h>
77 #include <linux/init.h>
78 #include <linux/slab.h>
79 #include <linux/jiffies.h>
80 #include <linux/i2c.h>
81 #include <linux/hwmon-sysfs.h>
82 #include <linux/hwmon.h>
83 #include <linux/err.h>
84 #include <linux/mutex.h>
85 #include <linux/sysfs.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  */
100 
101 static const unsigned short normal_i2c[] = {
102 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
103 
104 enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
105 	max6646, w83l771, max6696 };
106 
107 /*
108  * The LM90 registers
109  */
110 
111 #define LM90_REG_R_MAN_ID		0xFE
112 #define LM90_REG_R_CHIP_ID		0xFF
113 #define LM90_REG_R_CONFIG1		0x03
114 #define LM90_REG_W_CONFIG1		0x09
115 #define LM90_REG_R_CONFIG2		0xBF
116 #define LM90_REG_W_CONFIG2		0xBF
117 #define LM90_REG_R_CONVRATE		0x04
118 #define LM90_REG_W_CONVRATE		0x0A
119 #define LM90_REG_R_STATUS		0x02
120 #define LM90_REG_R_LOCAL_TEMP		0x00
121 #define LM90_REG_R_LOCAL_HIGH		0x05
122 #define LM90_REG_W_LOCAL_HIGH		0x0B
123 #define LM90_REG_R_LOCAL_LOW		0x06
124 #define LM90_REG_W_LOCAL_LOW		0x0C
125 #define LM90_REG_R_LOCAL_CRIT		0x20
126 #define LM90_REG_W_LOCAL_CRIT		0x20
127 #define LM90_REG_R_REMOTE_TEMPH		0x01
128 #define LM90_REG_R_REMOTE_TEMPL		0x10
129 #define LM90_REG_R_REMOTE_OFFSH		0x11
130 #define LM90_REG_W_REMOTE_OFFSH		0x11
131 #define LM90_REG_R_REMOTE_OFFSL		0x12
132 #define LM90_REG_W_REMOTE_OFFSL		0x12
133 #define LM90_REG_R_REMOTE_HIGHH		0x07
134 #define LM90_REG_W_REMOTE_HIGHH		0x0D
135 #define LM90_REG_R_REMOTE_HIGHL		0x13
136 #define LM90_REG_W_REMOTE_HIGHL		0x13
137 #define LM90_REG_R_REMOTE_LOWH		0x08
138 #define LM90_REG_W_REMOTE_LOWH		0x0E
139 #define LM90_REG_R_REMOTE_LOWL		0x14
140 #define LM90_REG_W_REMOTE_LOWL		0x14
141 #define LM90_REG_R_REMOTE_CRIT		0x19
142 #define LM90_REG_W_REMOTE_CRIT		0x19
143 #define LM90_REG_R_TCRIT_HYST		0x21
144 #define LM90_REG_W_TCRIT_HYST		0x21
145 
146 /* MAX6646/6647/6649/6657/6658/6659/6695/6696 registers */
147 
148 #define MAX6657_REG_R_LOCAL_TEMPL	0x11
149 #define MAX6696_REG_R_STATUS2		0x12
150 #define MAX6659_REG_R_REMOTE_EMERG	0x16
151 #define MAX6659_REG_W_REMOTE_EMERG	0x16
152 #define MAX6659_REG_R_LOCAL_EMERG	0x17
153 #define MAX6659_REG_W_LOCAL_EMERG	0x17
154 
155 #define LM90_DEF_CONVRATE_RVAL	6	/* Def conversion rate register value */
156 #define LM90_MAX_CONVRATE_MS	16000	/* Maximum conversion rate in ms */
157 
158 /*
159  * Device flags
160  */
161 #define LM90_FLAG_ADT7461_EXT	(1 << 0) /* ADT7461 extended mode	*/
162 /* Device features */
163 #define LM90_HAVE_OFFSET	(1 << 1) /* temperature offset register	*/
164 #define LM90_HAVE_LOCAL_EXT	(1 << 2) /* extended local temperature	*/
165 #define LM90_HAVE_REM_LIMIT_EXT	(1 << 3) /* extended remote limit	*/
166 #define LM90_HAVE_EMERGENCY	(1 << 4) /* 3rd upper (emergency) limit	*/
167 #define LM90_HAVE_EMERGENCY_ALARM (1 << 5)/* emergency alarm		*/
168 #define LM90_HAVE_TEMP3		(1 << 6) /* 3rd temperature sensor	*/
169 #define LM90_HAVE_BROKEN_ALERT	(1 << 7) /* Broken alert		*/
170 
171 /*
172  * Driver data (common to all clients)
173  */
174 
175 static const struct i2c_device_id lm90_id[] = {
176 	{ "adm1032", adm1032 },
177 	{ "adt7461", adt7461 },
178 	{ "adt7461a", adt7461 },
179 	{ "lm90", lm90 },
180 	{ "lm86", lm86 },
181 	{ "lm89", lm86 },
182 	{ "lm99", lm99 },
183 	{ "max6646", max6646 },
184 	{ "max6647", max6646 },
185 	{ "max6649", max6646 },
186 	{ "max6657", max6657 },
187 	{ "max6658", max6657 },
188 	{ "max6659", max6659 },
189 	{ "max6680", max6680 },
190 	{ "max6681", max6680 },
191 	{ "max6695", max6696 },
192 	{ "max6696", max6696 },
193 	{ "nct1008", adt7461 },
194 	{ "w83l771", w83l771 },
195 	{ }
196 };
197 MODULE_DEVICE_TABLE(i2c, lm90_id);
198 
199 /*
200  * chip type specific parameters
201  */
202 struct lm90_params {
203 	u32 flags;		/* Capabilities */
204 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
205 				/* Upper 8 bits for max6695/96 */
206 	u8 max_convrate;	/* Maximum conversion rate register value */
207 };
208 
209 static const struct lm90_params lm90_params[] = {
210 	[adm1032] = {
211 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
212 		  | LM90_HAVE_BROKEN_ALERT,
213 		.alert_alarms = 0x7c,
214 		.max_convrate = 10,
215 	},
216 	[adt7461] = {
217 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
218 		  | LM90_HAVE_BROKEN_ALERT,
219 		.alert_alarms = 0x7c,
220 		.max_convrate = 10,
221 	},
222 	[lm86] = {
223 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
224 		.alert_alarms = 0x7b,
225 		.max_convrate = 9,
226 	},
227 	[lm90] = {
228 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
229 		.alert_alarms = 0x7b,
230 		.max_convrate = 9,
231 	},
232 	[lm99] = {
233 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
234 		.alert_alarms = 0x7b,
235 		.max_convrate = 9,
236 	},
237 	[max6646] = {
238 		.flags = LM90_HAVE_LOCAL_EXT,
239 		.alert_alarms = 0x7c,
240 		.max_convrate = 6,
241 	},
242 	[max6657] = {
243 		.flags = LM90_HAVE_LOCAL_EXT,
244 		.alert_alarms = 0x7c,
245 		.max_convrate = 8,
246 	},
247 	[max6659] = {
248 		.flags = LM90_HAVE_LOCAL_EXT | LM90_HAVE_EMERGENCY,
249 		.alert_alarms = 0x7c,
250 		.max_convrate = 8,
251 	},
252 	[max6680] = {
253 		.flags = LM90_HAVE_OFFSET,
254 		.alert_alarms = 0x7c,
255 		.max_convrate = 7,
256 	},
257 	[max6696] = {
258 		.flags = LM90_HAVE_LOCAL_EXT | LM90_HAVE_EMERGENCY
259 		  | LM90_HAVE_EMERGENCY_ALARM | LM90_HAVE_TEMP3,
260 		.alert_alarms = 0x187c,
261 		.max_convrate = 6,
262 	},
263 	[w83l771] = {
264 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
265 		.alert_alarms = 0x7c,
266 		.max_convrate = 8,
267 	},
268 };
269 
270 /*
271  * Client data (each client gets its own)
272  */
273 
274 struct lm90_data {
275 	struct device *hwmon_dev;
276 	struct mutex update_lock;
277 	char valid; /* zero until following fields are valid */
278 	unsigned long last_updated; /* in jiffies */
279 	int kind;
280 	u32 flags;
281 
282 	int update_interval;	/* in milliseconds */
283 
284 	u8 config_orig;		/* Original configuration register value */
285 	u8 convrate_orig;	/* Original conversion rate register value */
286 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
287 				/* Upper 8 bits for max6695/96 */
288 	u8 max_convrate;	/* Maximum conversion rate */
289 
290 	/* registers values */
291 	s8 temp8[8];	/* 0: local low limit
292 			   1: local high limit
293 			   2: local critical limit
294 			   3: remote critical limit
295 			   4: local emergency limit (max6659 and max6695/96)
296 			   5: remote emergency limit (max6659 and max6695/96)
297 			   6: remote 2 critical limit (max6695/96 only)
298 			   7: remote 2 emergency limit (max6695/96 only) */
299 	s16 temp11[8];	/* 0: remote input
300 			   1: remote low limit
301 			   2: remote high limit
302 			   3: remote offset (except max6646, max6657/58/59,
303 					     and max6695/96)
304 			   4: local input
305 			   5: remote 2 input (max6695/96 only)
306 			   6: remote 2 low limit (max6695/96 only)
307 			   7: remote 2 high limit (ma6695/96 only) */
308 	u8 temp_hyst;
309 	u16 alarms; /* bitvector (upper 8 bits for max6695/96) */
310 };
311 
312 /*
313  * Support functions
314  */
315 
316 /*
317  * The ADM1032 supports PEC but not on write byte transactions, so we need
318  * to explicitly ask for a transaction without PEC.
319  */
320 static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value)
321 {
322 	return i2c_smbus_xfer(client->adapter, client->addr,
323 			      client->flags & ~I2C_CLIENT_PEC,
324 			      I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
325 }
326 
327 /*
328  * It is assumed that client->update_lock is held (unless we are in
329  * detection or initialization steps). This matters when PEC is enabled,
330  * because we don't want the address pointer to change between the write
331  * byte and the read byte transactions.
332  */
333 static int lm90_read_reg(struct i2c_client *client, u8 reg, u8 *value)
334 {
335 	int err;
336 
337 	if (client->flags & I2C_CLIENT_PEC) {
338 		err = adm1032_write_byte(client, reg);
339 		if (err >= 0)
340 			err = i2c_smbus_read_byte(client);
341 	} else
342 		err = i2c_smbus_read_byte_data(client, reg);
343 
344 	if (err < 0) {
345 		dev_warn(&client->dev, "Register %#02x read failed (%d)\n",
346 			 reg, err);
347 		return err;
348 	}
349 	*value = err;
350 
351 	return 0;
352 }
353 
354 static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl, u16 *value)
355 {
356 	int err;
357 	u8 oldh, newh, l;
358 
359 	/*
360 	 * There is a trick here. We have to read two registers to have the
361 	 * sensor temperature, but we have to beware a conversion could occur
362 	 * between the readings. The datasheet says we should either use
363 	 * the one-shot conversion register, which we don't want to do
364 	 * (disables hardware monitoring) or monitor the busy bit, which is
365 	 * impossible (we can't read the values and monitor that bit at the
366 	 * exact same time). So the solution used here is to read the high
367 	 * byte once, then the low byte, then the high byte again. If the new
368 	 * high byte matches the old one, then we have a valid reading. Else
369 	 * we have to read the low byte again, and now we believe we have a
370 	 * correct reading.
371 	 */
372 	if ((err = lm90_read_reg(client, regh, &oldh))
373 	 || (err = lm90_read_reg(client, regl, &l))
374 	 || (err = lm90_read_reg(client, regh, &newh)))
375 		return err;
376 	if (oldh != newh) {
377 		err = lm90_read_reg(client, regl, &l);
378 		if (err)
379 			return err;
380 	}
381 	*value = (newh << 8) | l;
382 
383 	return 0;
384 }
385 
386 /*
387  * client->update_lock must be held when calling this function (unless we are
388  * in detection or initialization steps), and while a remote channel other
389  * than channel 0 is selected. Also, calling code must make sure to re-select
390  * external channel 0 before releasing the lock. This is necessary because
391  * various registers have different meanings as a result of selecting a
392  * non-default remote channel.
393  */
394 static inline void lm90_select_remote_channel(struct i2c_client *client,
395 					      struct lm90_data *data,
396 					      int channel)
397 {
398 	u8 config;
399 
400 	if (data->kind == max6696) {
401 		lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
402 		config &= ~0x08;
403 		if (channel)
404 			config |= 0x08;
405 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
406 					  config);
407 	}
408 }
409 
410 /*
411  * Set conversion rate.
412  * client->update_lock must be held when calling this function (unless we are
413  * in detection or initialization steps).
414  */
415 static void lm90_set_convrate(struct i2c_client *client, struct lm90_data *data,
416 			      unsigned int interval)
417 {
418 	int i;
419 	unsigned int update_interval;
420 
421 	/* Shift calculations to avoid rounding errors */
422 	interval <<= 6;
423 
424 	/* find the nearest update rate */
425 	for (i = 0, update_interval = LM90_MAX_CONVRATE_MS << 6;
426 	     i < data->max_convrate; i++, update_interval >>= 1)
427 		if (interval >= update_interval * 3 / 4)
428 			break;
429 
430 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, i);
431 	data->update_interval = DIV_ROUND_CLOSEST(update_interval, 64);
432 }
433 
434 static struct lm90_data *lm90_update_device(struct device *dev)
435 {
436 	struct i2c_client *client = to_i2c_client(dev);
437 	struct lm90_data *data = i2c_get_clientdata(client);
438 	unsigned long next_update;
439 
440 	mutex_lock(&data->update_lock);
441 
442 	next_update = data->last_updated
443 	  + msecs_to_jiffies(data->update_interval) + 1;
444 	if (time_after(jiffies, next_update) || !data->valid) {
445 		u8 h, l;
446 		u8 alarms;
447 
448 		dev_dbg(&client->dev, "Updating lm90 data.\n");
449 		lm90_read_reg(client, LM90_REG_R_LOCAL_LOW, &data->temp8[0]);
450 		lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH, &data->temp8[1]);
451 		lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT, &data->temp8[2]);
452 		lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[3]);
453 		lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
454 
455 		if (data->flags & LM90_HAVE_LOCAL_EXT) {
456 			lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
457 				    MAX6657_REG_R_LOCAL_TEMPL,
458 				    &data->temp11[4]);
459 		} else {
460 			if (lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP,
461 					  &h) == 0)
462 				data->temp11[4] = h << 8;
463 		}
464 		lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
465 			    LM90_REG_R_REMOTE_TEMPL, &data->temp11[0]);
466 
467 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h) == 0) {
468 			data->temp11[1] = h << 8;
469 			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
470 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL,
471 					  &l) == 0)
472 				data->temp11[1] |= l;
473 		}
474 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h) == 0) {
475 			data->temp11[2] = h << 8;
476 			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
477 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL,
478 					  &l) == 0)
479 				data->temp11[2] |= l;
480 		}
481 
482 		if (data->flags & LM90_HAVE_OFFSET) {
483 			if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
484 					  &h) == 0
485 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,
486 					  &l) == 0)
487 				data->temp11[3] = (h << 8) | l;
488 		}
489 		if (data->flags & LM90_HAVE_EMERGENCY) {
490 			lm90_read_reg(client, MAX6659_REG_R_LOCAL_EMERG,
491 				      &data->temp8[4]);
492 			lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
493 				      &data->temp8[5]);
494 		}
495 		lm90_read_reg(client, LM90_REG_R_STATUS, &alarms);
496 		data->alarms = alarms;	/* save as 16 bit value */
497 
498 		if (data->kind == max6696) {
499 			lm90_select_remote_channel(client, data, 1);
500 			lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT,
501 				      &data->temp8[6]);
502 			lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
503 				      &data->temp8[7]);
504 			lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
505 				    LM90_REG_R_REMOTE_TEMPL, &data->temp11[5]);
506 			if (!lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h))
507 				data->temp11[6] = h << 8;
508 			if (!lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h))
509 				data->temp11[7] = h << 8;
510 			lm90_select_remote_channel(client, data, 0);
511 
512 			if (!lm90_read_reg(client, MAX6696_REG_R_STATUS2,
513 					   &alarms))
514 				data->alarms |= alarms << 8;
515 		}
516 
517 		/* Re-enable ALERT# output if it was originally enabled and
518 		 * relevant alarms are all clear */
519 		if ((data->config_orig & 0x80) == 0
520 		 && (data->alarms & data->alert_alarms) == 0) {
521 			u8 config;
522 
523 			lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
524 			if (config & 0x80) {
525 				dev_dbg(&client->dev, "Re-enabling ALERT#\n");
526 				i2c_smbus_write_byte_data(client,
527 							  LM90_REG_W_CONFIG1,
528 							  config & ~0x80);
529 			}
530 		}
531 
532 		data->last_updated = jiffies;
533 		data->valid = 1;
534 	}
535 
536 	mutex_unlock(&data->update_lock);
537 
538 	return data;
539 }
540 
541 /*
542  * Conversions
543  * For local temperatures and limits, critical limits and the hysteresis
544  * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
545  * For remote temperatures and limits, it uses signed 11-bit values with
546  * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.  Some
547  * Maxim chips use unsigned values.
548  */
549 
550 static inline int temp_from_s8(s8 val)
551 {
552 	return val * 1000;
553 }
554 
555 static inline int temp_from_u8(u8 val)
556 {
557 	return val * 1000;
558 }
559 
560 static inline int temp_from_s16(s16 val)
561 {
562 	return val / 32 * 125;
563 }
564 
565 static inline int temp_from_u16(u16 val)
566 {
567 	return val / 32 * 125;
568 }
569 
570 static s8 temp_to_s8(long val)
571 {
572 	if (val <= -128000)
573 		return -128;
574 	if (val >= 127000)
575 		return 127;
576 	if (val < 0)
577 		return (val - 500) / 1000;
578 	return (val + 500) / 1000;
579 }
580 
581 static u8 temp_to_u8(long val)
582 {
583 	if (val <= 0)
584 		return 0;
585 	if (val >= 255000)
586 		return 255;
587 	return (val + 500) / 1000;
588 }
589 
590 static s16 temp_to_s16(long val)
591 {
592 	if (val <= -128000)
593 		return 0x8000;
594 	if (val >= 127875)
595 		return 0x7FE0;
596 	if (val < 0)
597 		return (val - 62) / 125 * 32;
598 	return (val + 62) / 125 * 32;
599 }
600 
601 static u8 hyst_to_reg(long val)
602 {
603 	if (val <= 0)
604 		return 0;
605 	if (val >= 30500)
606 		return 31;
607 	return (val + 500) / 1000;
608 }
609 
610 /*
611  * ADT7461 in compatibility mode is almost identical to LM90 except that
612  * attempts to write values that are outside the range 0 < temp < 127 are
613  * treated as the boundary value.
614  *
615  * ADT7461 in "extended mode" operation uses unsigned integers offset by
616  * 64 (e.g., 0 -> -64 degC).  The range is restricted to -64..191 degC.
617  */
618 static inline int temp_from_u8_adt7461(struct lm90_data *data, u8 val)
619 {
620 	if (data->flags & LM90_FLAG_ADT7461_EXT)
621 		return (val - 64) * 1000;
622 	else
623 		return temp_from_s8(val);
624 }
625 
626 static inline int temp_from_u16_adt7461(struct lm90_data *data, u16 val)
627 {
628 	if (data->flags & LM90_FLAG_ADT7461_EXT)
629 		return (val - 0x4000) / 64 * 250;
630 	else
631 		return temp_from_s16(val);
632 }
633 
634 static u8 temp_to_u8_adt7461(struct lm90_data *data, long val)
635 {
636 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
637 		if (val <= -64000)
638 			return 0;
639 		if (val >= 191000)
640 			return 0xFF;
641 		return (val + 500 + 64000) / 1000;
642 	} else {
643 		if (val <= 0)
644 			return 0;
645 		if (val >= 127000)
646 			return 127;
647 		return (val + 500) / 1000;
648 	}
649 }
650 
651 static u16 temp_to_u16_adt7461(struct lm90_data *data, long val)
652 {
653 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
654 		if (val <= -64000)
655 			return 0;
656 		if (val >= 191750)
657 			return 0xFFC0;
658 		return (val + 64000 + 125) / 250 * 64;
659 	} else {
660 		if (val <= 0)
661 			return 0;
662 		if (val >= 127750)
663 			return 0x7FC0;
664 		return (val + 125) / 250 * 64;
665 	}
666 }
667 
668 /*
669  * Sysfs stuff
670  */
671 
672 static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
673 			  char *buf)
674 {
675 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
676 	struct lm90_data *data = lm90_update_device(dev);
677 	int temp;
678 
679 	if (data->kind == adt7461)
680 		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
681 	else if (data->kind == max6646)
682 		temp = temp_from_u8(data->temp8[attr->index]);
683 	else
684 		temp = temp_from_s8(data->temp8[attr->index]);
685 
686 	/* +16 degrees offset for temp2 for the LM99 */
687 	if (data->kind == lm99 && attr->index == 3)
688 		temp += 16000;
689 
690 	return sprintf(buf, "%d\n", temp);
691 }
692 
693 static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
694 			 const char *buf, size_t count)
695 {
696 	static const u8 reg[8] = {
697 		LM90_REG_W_LOCAL_LOW,
698 		LM90_REG_W_LOCAL_HIGH,
699 		LM90_REG_W_LOCAL_CRIT,
700 		LM90_REG_W_REMOTE_CRIT,
701 		MAX6659_REG_W_LOCAL_EMERG,
702 		MAX6659_REG_W_REMOTE_EMERG,
703 		LM90_REG_W_REMOTE_CRIT,
704 		MAX6659_REG_W_REMOTE_EMERG,
705 	};
706 
707 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
708 	struct i2c_client *client = to_i2c_client(dev);
709 	struct lm90_data *data = i2c_get_clientdata(client);
710 	int nr = attr->index;
711 	long val;
712 	int err;
713 
714 	err = strict_strtol(buf, 10, &val);
715 	if (err < 0)
716 		return err;
717 
718 	/* +16 degrees offset for temp2 for the LM99 */
719 	if (data->kind == lm99 && attr->index == 3)
720 		val -= 16000;
721 
722 	mutex_lock(&data->update_lock);
723 	if (data->kind == adt7461)
724 		data->temp8[nr] = temp_to_u8_adt7461(data, val);
725 	else if (data->kind == max6646)
726 		data->temp8[nr] = temp_to_u8(val);
727 	else
728 		data->temp8[nr] = temp_to_s8(val);
729 
730 	lm90_select_remote_channel(client, data, nr >= 6);
731 	i2c_smbus_write_byte_data(client, reg[nr], data->temp8[nr]);
732 	lm90_select_remote_channel(client, data, 0);
733 
734 	mutex_unlock(&data->update_lock);
735 	return count;
736 }
737 
738 static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
739 			   char *buf)
740 {
741 	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
742 	struct lm90_data *data = lm90_update_device(dev);
743 	int temp;
744 
745 	if (data->kind == adt7461)
746 		temp = temp_from_u16_adt7461(data, data->temp11[attr->index]);
747 	else if (data->kind == max6646)
748 		temp = temp_from_u16(data->temp11[attr->index]);
749 	else
750 		temp = temp_from_s16(data->temp11[attr->index]);
751 
752 	/* +16 degrees offset for temp2 for the LM99 */
753 	if (data->kind == lm99 &&  attr->index <= 2)
754 		temp += 16000;
755 
756 	return sprintf(buf, "%d\n", temp);
757 }
758 
759 static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
760 			  const char *buf, size_t count)
761 {
762 	struct {
763 		u8 high;
764 		u8 low;
765 		int channel;
766 	} reg[5] = {
767 		{ LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL, 0 },
768 		{ LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 0 },
769 		{ LM90_REG_W_REMOTE_OFFSH, LM90_REG_W_REMOTE_OFFSL, 0 },
770 		{ LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL, 1 },
771 		{ LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 1 }
772 	};
773 
774 	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
775 	struct i2c_client *client = to_i2c_client(dev);
776 	struct lm90_data *data = i2c_get_clientdata(client);
777 	int nr = attr->nr;
778 	int index = attr->index;
779 	long val;
780 	int err;
781 
782 	err = strict_strtol(buf, 10, &val);
783 	if (err < 0)
784 		return err;
785 
786 	/* +16 degrees offset for temp2 for the LM99 */
787 	if (data->kind == lm99 && index <= 2)
788 		val -= 16000;
789 
790 	mutex_lock(&data->update_lock);
791 	if (data->kind == adt7461)
792 		data->temp11[index] = temp_to_u16_adt7461(data, val);
793 	else if (data->kind == max6646)
794 		data->temp11[index] = temp_to_u8(val) << 8;
795 	else if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
796 		data->temp11[index] = temp_to_s16(val);
797 	else
798 		data->temp11[index] = temp_to_s8(val) << 8;
799 
800 	lm90_select_remote_channel(client, data, reg[nr].channel);
801 	i2c_smbus_write_byte_data(client, reg[nr].high,
802 				  data->temp11[index] >> 8);
803 	if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
804 		i2c_smbus_write_byte_data(client, reg[nr].low,
805 					  data->temp11[index] & 0xff);
806 	lm90_select_remote_channel(client, data, 0);
807 
808 	mutex_unlock(&data->update_lock);
809 	return count;
810 }
811 
812 static ssize_t show_temphyst(struct device *dev,
813 			     struct device_attribute *devattr,
814 			     char *buf)
815 {
816 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
817 	struct lm90_data *data = lm90_update_device(dev);
818 	int temp;
819 
820 	if (data->kind == adt7461)
821 		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
822 	else if (data->kind == max6646)
823 		temp = temp_from_u8(data->temp8[attr->index]);
824 	else
825 		temp = temp_from_s8(data->temp8[attr->index]);
826 
827 	/* +16 degrees offset for temp2 for the LM99 */
828 	if (data->kind == lm99 && attr->index == 3)
829 		temp += 16000;
830 
831 	return sprintf(buf, "%d\n", temp - temp_from_s8(data->temp_hyst));
832 }
833 
834 static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
835 			    const char *buf, size_t count)
836 {
837 	struct i2c_client *client = to_i2c_client(dev);
838 	struct lm90_data *data = i2c_get_clientdata(client);
839 	long val;
840 	int err;
841 	int temp;
842 
843 	err = strict_strtol(buf, 10, &val);
844 	if (err < 0)
845 		return err;
846 
847 	mutex_lock(&data->update_lock);
848 	if (data->kind == adt7461)
849 		temp = temp_from_u8_adt7461(data, data->temp8[2]);
850 	else if (data->kind == max6646)
851 		temp = temp_from_u8(data->temp8[2]);
852 	else
853 		temp = temp_from_s8(data->temp8[2]);
854 
855 	data->temp_hyst = hyst_to_reg(temp - val);
856 	i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
857 				  data->temp_hyst);
858 	mutex_unlock(&data->update_lock);
859 	return count;
860 }
861 
862 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
863 			   char *buf)
864 {
865 	struct lm90_data *data = lm90_update_device(dev);
866 	return sprintf(buf, "%d\n", data->alarms);
867 }
868 
869 static ssize_t show_alarm(struct device *dev, struct device_attribute
870 			  *devattr, char *buf)
871 {
872 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
873 	struct lm90_data *data = lm90_update_device(dev);
874 	int bitnr = attr->index;
875 
876 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
877 }
878 
879 static ssize_t show_update_interval(struct device *dev,
880 				    struct device_attribute *attr, char *buf)
881 {
882 	struct lm90_data *data = dev_get_drvdata(dev);
883 
884 	return sprintf(buf, "%u\n", data->update_interval);
885 }
886 
887 static ssize_t set_update_interval(struct device *dev,
888 				   struct device_attribute *attr,
889 				   const char *buf, size_t count)
890 {
891 	struct i2c_client *client = to_i2c_client(dev);
892 	struct lm90_data *data = i2c_get_clientdata(client);
893 	unsigned long val;
894 	int err;
895 
896 	err = strict_strtoul(buf, 10, &val);
897 	if (err)
898 		return err;
899 
900 	mutex_lock(&data->update_lock);
901 	lm90_set_convrate(client, data, val);
902 	mutex_unlock(&data->update_lock);
903 
904 	return count;
905 }
906 
907 static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp11, NULL, 0, 4);
908 static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp11, NULL, 0, 0);
909 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
910 	set_temp8, 0);
911 static SENSOR_DEVICE_ATTR_2(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
912 	set_temp11, 0, 1);
913 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
914 	set_temp8, 1);
915 static SENSOR_DEVICE_ATTR_2(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
916 	set_temp11, 1, 2);
917 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
918 	set_temp8, 2);
919 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
920 	set_temp8, 3);
921 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
922 	set_temphyst, 2);
923 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 3);
924 static SENSOR_DEVICE_ATTR_2(temp2_offset, S_IWUSR | S_IRUGO, show_temp11,
925 	set_temp11, 2, 3);
926 
927 /* Individual alarm files */
928 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
929 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
930 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
931 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
932 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
933 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 5);
934 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
935 /* Raw alarm file for compatibility */
936 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
937 
938 static DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR, show_update_interval,
939 		   set_update_interval);
940 
941 static struct attribute *lm90_attributes[] = {
942 	&sensor_dev_attr_temp1_input.dev_attr.attr,
943 	&sensor_dev_attr_temp2_input.dev_attr.attr,
944 	&sensor_dev_attr_temp1_min.dev_attr.attr,
945 	&sensor_dev_attr_temp2_min.dev_attr.attr,
946 	&sensor_dev_attr_temp1_max.dev_attr.attr,
947 	&sensor_dev_attr_temp2_max.dev_attr.attr,
948 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
949 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
950 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
951 	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
952 
953 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
954 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
955 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
956 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
957 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
958 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
959 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
960 	&dev_attr_alarms.attr,
961 	&dev_attr_update_interval.attr,
962 	NULL
963 };
964 
965 static const struct attribute_group lm90_group = {
966 	.attrs = lm90_attributes,
967 };
968 
969 /*
970  * Additional attributes for devices with emergency sensors
971  */
972 static SENSOR_DEVICE_ATTR(temp1_emergency, S_IWUSR | S_IRUGO, show_temp8,
973 	set_temp8, 4);
974 static SENSOR_DEVICE_ATTR(temp2_emergency, S_IWUSR | S_IRUGO, show_temp8,
975 	set_temp8, 5);
976 static SENSOR_DEVICE_ATTR(temp1_emergency_hyst, S_IRUGO, show_temphyst,
977 			  NULL, 4);
978 static SENSOR_DEVICE_ATTR(temp2_emergency_hyst, S_IRUGO, show_temphyst,
979 			  NULL, 5);
980 
981 static struct attribute *lm90_emergency_attributes[] = {
982 	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
983 	&sensor_dev_attr_temp2_emergency.dev_attr.attr,
984 	&sensor_dev_attr_temp1_emergency_hyst.dev_attr.attr,
985 	&sensor_dev_attr_temp2_emergency_hyst.dev_attr.attr,
986 	NULL
987 };
988 
989 static const struct attribute_group lm90_emergency_group = {
990 	.attrs = lm90_emergency_attributes,
991 };
992 
993 static SENSOR_DEVICE_ATTR(temp1_emergency_alarm, S_IRUGO, show_alarm, NULL, 15);
994 static SENSOR_DEVICE_ATTR(temp2_emergency_alarm, S_IRUGO, show_alarm, NULL, 13);
995 
996 static struct attribute *lm90_emergency_alarm_attributes[] = {
997 	&sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
998 	&sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
999 	NULL
1000 };
1001 
1002 static const struct attribute_group lm90_emergency_alarm_group = {
1003 	.attrs = lm90_emergency_alarm_attributes,
1004 };
1005 
1006 /*
1007  * Additional attributes for devices with 3 temperature sensors
1008  */
1009 static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp11, NULL, 0, 5);
1010 static SENSOR_DEVICE_ATTR_2(temp3_min, S_IWUSR | S_IRUGO, show_temp11,
1011 	set_temp11, 3, 6);
1012 static SENSOR_DEVICE_ATTR_2(temp3_max, S_IWUSR | S_IRUGO, show_temp11,
1013 	set_temp11, 4, 7);
1014 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp8,
1015 	set_temp8, 6);
1016 static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO, show_temphyst, NULL, 6);
1017 static SENSOR_DEVICE_ATTR(temp3_emergency, S_IWUSR | S_IRUGO, show_temp8,
1018 	set_temp8, 7);
1019 static SENSOR_DEVICE_ATTR(temp3_emergency_hyst, S_IRUGO, show_temphyst,
1020 			  NULL, 7);
1021 
1022 static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
1023 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 10);
1024 static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_alarm, NULL, 11);
1025 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 12);
1026 static SENSOR_DEVICE_ATTR(temp3_emergency_alarm, S_IRUGO, show_alarm, NULL, 14);
1027 
1028 static struct attribute *lm90_temp3_attributes[] = {
1029 	&sensor_dev_attr_temp3_input.dev_attr.attr,
1030 	&sensor_dev_attr_temp3_min.dev_attr.attr,
1031 	&sensor_dev_attr_temp3_max.dev_attr.attr,
1032 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
1033 	&sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
1034 	&sensor_dev_attr_temp3_emergency.dev_attr.attr,
1035 	&sensor_dev_attr_temp3_emergency_hyst.dev_attr.attr,
1036 
1037 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
1038 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
1039 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
1040 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
1041 	&sensor_dev_attr_temp3_emergency_alarm.dev_attr.attr,
1042 	NULL
1043 };
1044 
1045 static const struct attribute_group lm90_temp3_group = {
1046 	.attrs = lm90_temp3_attributes,
1047 };
1048 
1049 /* pec used for ADM1032 only */
1050 static ssize_t show_pec(struct device *dev, struct device_attribute *dummy,
1051 			char *buf)
1052 {
1053 	struct i2c_client *client = to_i2c_client(dev);
1054 	return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
1055 }
1056 
1057 static ssize_t set_pec(struct device *dev, struct device_attribute *dummy,
1058 		       const char *buf, size_t count)
1059 {
1060 	struct i2c_client *client = to_i2c_client(dev);
1061 	long val;
1062 	int err;
1063 
1064 	err = strict_strtol(buf, 10, &val);
1065 	if (err < 0)
1066 		return err;
1067 
1068 	switch (val) {
1069 	case 0:
1070 		client->flags &= ~I2C_CLIENT_PEC;
1071 		break;
1072 	case 1:
1073 		client->flags |= I2C_CLIENT_PEC;
1074 		break;
1075 	default:
1076 		return -EINVAL;
1077 	}
1078 
1079 	return count;
1080 }
1081 
1082 static DEVICE_ATTR(pec, S_IWUSR | S_IRUGO, show_pec, set_pec);
1083 
1084 /*
1085  * Real code
1086  */
1087 
1088 /* Return 0 if detection is successful, -ENODEV otherwise */
1089 static int lm90_detect(struct i2c_client *new_client,
1090 		       struct i2c_board_info *info)
1091 {
1092 	struct i2c_adapter *adapter = new_client->adapter;
1093 	int address = new_client->addr;
1094 	const char *name = NULL;
1095 	int man_id, chip_id, reg_config1, reg_convrate;
1096 
1097 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
1098 		return -ENODEV;
1099 
1100 	/* detection and identification */
1101 	if ((man_id = i2c_smbus_read_byte_data(new_client,
1102 						LM90_REG_R_MAN_ID)) < 0
1103 	 || (chip_id = i2c_smbus_read_byte_data(new_client,
1104 						LM90_REG_R_CHIP_ID)) < 0
1105 	 || (reg_config1 = i2c_smbus_read_byte_data(new_client,
1106 						LM90_REG_R_CONFIG1)) < 0
1107 	 || (reg_convrate = i2c_smbus_read_byte_data(new_client,
1108 						LM90_REG_R_CONVRATE)) < 0)
1109 		return -ENODEV;
1110 
1111 	if ((address == 0x4C || address == 0x4D)
1112 	 && man_id == 0x01) { /* National Semiconductor */
1113 		int reg_config2;
1114 
1115 		reg_config2 = i2c_smbus_read_byte_data(new_client,
1116 						LM90_REG_R_CONFIG2);
1117 		if (reg_config2 < 0)
1118 			return -ENODEV;
1119 
1120 		if ((reg_config1 & 0x2A) == 0x00
1121 		 && (reg_config2 & 0xF8) == 0x00
1122 		 && reg_convrate <= 0x09) {
1123 			if (address == 0x4C
1124 			 && (chip_id & 0xF0) == 0x20) { /* LM90 */
1125 				name = "lm90";
1126 			} else
1127 			if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
1128 				name = "lm99";
1129 				dev_info(&adapter->dev,
1130 					 "Assuming LM99 chip at 0x%02x\n",
1131 					 address);
1132 				dev_info(&adapter->dev,
1133 					 "If it is an LM89, instantiate it "
1134 					 "with the new_device sysfs "
1135 					 "interface\n");
1136 			} else
1137 			if (address == 0x4C
1138 			 && (chip_id & 0xF0) == 0x10) { /* LM86 */
1139 				name = "lm86";
1140 			}
1141 		}
1142 	} else
1143 	if ((address == 0x4C || address == 0x4D)
1144 	 && man_id == 0x41) { /* Analog Devices */
1145 		if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
1146 		 && (reg_config1 & 0x3F) == 0x00
1147 		 && reg_convrate <= 0x0A) {
1148 			name = "adm1032";
1149 			/* The ADM1032 supports PEC, but only if combined
1150 			   transactions are not used. */
1151 			if (i2c_check_functionality(adapter,
1152 						    I2C_FUNC_SMBUS_BYTE))
1153 				info->flags |= I2C_CLIENT_PEC;
1154 		} else
1155 		if (chip_id == 0x51 /* ADT7461 */
1156 		 && (reg_config1 & 0x1B) == 0x00
1157 		 && reg_convrate <= 0x0A) {
1158 			name = "adt7461";
1159 		} else
1160 		if (chip_id == 0x57 /* ADT7461A, NCT1008 */
1161 		 && (reg_config1 & 0x1B) == 0x00
1162 		 && reg_convrate <= 0x0A) {
1163 			name = "adt7461a";
1164 		}
1165 	} else
1166 	if (man_id == 0x4D) { /* Maxim */
1167 		int reg_emerg, reg_emerg2, reg_status2;
1168 
1169 		/*
1170 		 * We read MAX6659_REG_R_REMOTE_EMERG twice, and re-read
1171 		 * LM90_REG_R_MAN_ID in between. If MAX6659_REG_R_REMOTE_EMERG
1172 		 * exists, both readings will reflect the same value. Otherwise,
1173 		 * the readings will be different.
1174 		 */
1175 		if ((reg_emerg = i2c_smbus_read_byte_data(new_client,
1176 						MAX6659_REG_R_REMOTE_EMERG)) < 0
1177 		 || i2c_smbus_read_byte_data(new_client, LM90_REG_R_MAN_ID) < 0
1178 		 || (reg_emerg2 = i2c_smbus_read_byte_data(new_client,
1179 						MAX6659_REG_R_REMOTE_EMERG)) < 0
1180 		 || (reg_status2 = i2c_smbus_read_byte_data(new_client,
1181 						MAX6696_REG_R_STATUS2)) < 0)
1182 			return -ENODEV;
1183 
1184 		/*
1185 		 * The MAX6657, MAX6658 and MAX6659 do NOT have a chip_id
1186 		 * register. Reading from that address will return the last
1187 		 * read value, which in our case is those of the man_id
1188 		 * register. Likewise, the config1 register seems to lack a
1189 		 * low nibble, so the value will be those of the previous
1190 		 * read, so in our case those of the man_id register.
1191 		 * MAX6659 has a third set of upper temperature limit registers.
1192 		 * Those registers also return values on MAX6657 and MAX6658,
1193 		 * thus the only way to detect MAX6659 is by its address.
1194 		 * For this reason it will be mis-detected as MAX6657 if its
1195 		 * address is 0x4C.
1196 		 */
1197 		if (chip_id == man_id
1198 		 && (address == 0x4C || address == 0x4D || address == 0x4E)
1199 		 && (reg_config1 & 0x1F) == (man_id & 0x0F)
1200 		 && reg_convrate <= 0x09) {
1201 			if (address == 0x4C)
1202 				name = "max6657";
1203 			else
1204 				name = "max6659";
1205 		} else
1206 		/*
1207 		 * Even though MAX6695 and MAX6696 do not have a chip ID
1208 		 * register, reading it returns 0x01. Bit 4 of the config1
1209 		 * register is unused and should return zero when read. Bit 0 of
1210 		 * the status2 register is unused and should return zero when
1211 		 * read.
1212 		 *
1213 		 * MAX6695 and MAX6696 have an additional set of temperature
1214 		 * limit registers. We can detect those chips by checking if
1215 		 * one of those registers exists.
1216 		 */
1217 		if (chip_id == 0x01
1218 		 && (reg_config1 & 0x10) == 0x00
1219 		 && (reg_status2 & 0x01) == 0x00
1220 		 && reg_emerg == reg_emerg2
1221 		 && reg_convrate <= 0x07) {
1222 			name = "max6696";
1223 		} else
1224 		/*
1225 		 * The chip_id register of the MAX6680 and MAX6681 holds the
1226 		 * revision of the chip. The lowest bit of the config1 register
1227 		 * is unused and should return zero when read, so should the
1228 		 * second to last bit of config1 (software reset).
1229 		 */
1230 		if (chip_id == 0x01
1231 		 && (reg_config1 & 0x03) == 0x00
1232 		 && reg_convrate <= 0x07) {
1233 			name = "max6680";
1234 		} else
1235 		/*
1236 		 * The chip_id register of the MAX6646/6647/6649 holds the
1237 		 * revision of the chip. The lowest 6 bits of the config1
1238 		 * register are unused and should return zero when read.
1239 		 */
1240 		if (chip_id == 0x59
1241 		 && (reg_config1 & 0x3f) == 0x00
1242 		 && reg_convrate <= 0x07) {
1243 			name = "max6646";
1244 		}
1245 	} else
1246 	if (address == 0x4C
1247 	 && man_id == 0x5C) { /* Winbond/Nuvoton */
1248 		int reg_config2;
1249 
1250 		reg_config2 = i2c_smbus_read_byte_data(new_client,
1251 						LM90_REG_R_CONFIG2);
1252 		if (reg_config2 < 0)
1253 			return -ENODEV;
1254 
1255 		if ((reg_config1 & 0x2A) == 0x00
1256 		 && (reg_config2 & 0xF8) == 0x00) {
1257 			if (chip_id == 0x01 /* W83L771W/G */
1258 			 && reg_convrate <= 0x09) {
1259 				name = "w83l771";
1260 			} else
1261 			if ((chip_id & 0xFE) == 0x10 /* W83L771AWG/ASG */
1262 			 && reg_convrate <= 0x08) {
1263 				name = "w83l771";
1264 			}
1265 		}
1266 	}
1267 
1268 	if (!name) { /* identification failed */
1269 		dev_dbg(&adapter->dev,
1270 			"Unsupported chip at 0x%02x (man_id=0x%02X, "
1271 			"chip_id=0x%02X)\n", address, man_id, chip_id);
1272 		return -ENODEV;
1273 	}
1274 
1275 	strlcpy(info->type, name, I2C_NAME_SIZE);
1276 
1277 	return 0;
1278 }
1279 
1280 static void lm90_remove_files(struct i2c_client *client, struct lm90_data *data)
1281 {
1282 	if (data->flags & LM90_HAVE_TEMP3)
1283 		sysfs_remove_group(&client->dev.kobj, &lm90_temp3_group);
1284 	if (data->flags & LM90_HAVE_EMERGENCY_ALARM)
1285 		sysfs_remove_group(&client->dev.kobj,
1286 				   &lm90_emergency_alarm_group);
1287 	if (data->flags & LM90_HAVE_EMERGENCY)
1288 		sysfs_remove_group(&client->dev.kobj,
1289 				   &lm90_emergency_group);
1290 	if (data->flags & LM90_HAVE_OFFSET)
1291 		device_remove_file(&client->dev,
1292 				   &sensor_dev_attr_temp2_offset.dev_attr);
1293 	device_remove_file(&client->dev, &dev_attr_pec);
1294 	sysfs_remove_group(&client->dev.kobj, &lm90_group);
1295 }
1296 
1297 static void lm90_init_client(struct i2c_client *client)
1298 {
1299 	u8 config, convrate;
1300 	struct lm90_data *data = i2c_get_clientdata(client);
1301 
1302 	if (lm90_read_reg(client, LM90_REG_R_CONVRATE, &convrate) < 0) {
1303 		dev_warn(&client->dev, "Failed to read convrate register!\n");
1304 		convrate = LM90_DEF_CONVRATE_RVAL;
1305 	}
1306 	data->convrate_orig = convrate;
1307 
1308 	/*
1309 	 * Start the conversions.
1310 	 */
1311 	lm90_set_convrate(client, data, 500);	/* 500ms; 2Hz conversion rate */
1312 	if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) {
1313 		dev_warn(&client->dev, "Initialization failed!\n");
1314 		return;
1315 	}
1316 	data->config_orig = config;
1317 
1318 	/* Check Temperature Range Select */
1319 	if (data->kind == adt7461) {
1320 		if (config & 0x04)
1321 			data->flags |= LM90_FLAG_ADT7461_EXT;
1322 	}
1323 
1324 	/*
1325 	 * Put MAX6680/MAX8881 into extended resolution (bit 0x10,
1326 	 * 0.125 degree resolution) and range (0x08, extend range
1327 	 * to -64 degree) mode for the remote temperature sensor.
1328 	 */
1329 	if (data->kind == max6680)
1330 		config |= 0x18;
1331 
1332 	/*
1333 	 * Select external channel 0 for max6695/96
1334 	 */
1335 	if (data->kind == max6696)
1336 		config &= ~0x08;
1337 
1338 	config &= 0xBF;	/* run */
1339 	if (config != data->config_orig) /* Only write if changed */
1340 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config);
1341 }
1342 
1343 static int lm90_probe(struct i2c_client *new_client,
1344 		      const struct i2c_device_id *id)
1345 {
1346 	struct i2c_adapter *adapter = to_i2c_adapter(new_client->dev.parent);
1347 	struct lm90_data *data;
1348 	int err;
1349 
1350 	data = kzalloc(sizeof(struct lm90_data), GFP_KERNEL);
1351 	if (!data) {
1352 		err = -ENOMEM;
1353 		goto exit;
1354 	}
1355 	i2c_set_clientdata(new_client, data);
1356 	mutex_init(&data->update_lock);
1357 
1358 	/* Set the device type */
1359 	data->kind = id->driver_data;
1360 	if (data->kind == adm1032) {
1361 		if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
1362 			new_client->flags &= ~I2C_CLIENT_PEC;
1363 	}
1364 
1365 	/* Different devices have different alarm bits triggering the
1366 	 * ALERT# output */
1367 	data->alert_alarms = lm90_params[data->kind].alert_alarms;
1368 
1369 	/* Set chip capabilities */
1370 	data->flags = lm90_params[data->kind].flags;
1371 
1372 	/* Set maximum conversion rate */
1373 	data->max_convrate = lm90_params[data->kind].max_convrate;
1374 
1375 	/* Initialize the LM90 chip */
1376 	lm90_init_client(new_client);
1377 
1378 	/* Register sysfs hooks */
1379 	err = sysfs_create_group(&new_client->dev.kobj, &lm90_group);
1380 	if (err)
1381 		goto exit_free;
1382 	if (new_client->flags & I2C_CLIENT_PEC) {
1383 		err = device_create_file(&new_client->dev, &dev_attr_pec);
1384 		if (err)
1385 			goto exit_remove_files;
1386 	}
1387 	if (data->flags & LM90_HAVE_OFFSET) {
1388 		err = device_create_file(&new_client->dev,
1389 					&sensor_dev_attr_temp2_offset.dev_attr);
1390 		if (err)
1391 			goto exit_remove_files;
1392 	}
1393 	if (data->flags & LM90_HAVE_EMERGENCY) {
1394 		err = sysfs_create_group(&new_client->dev.kobj,
1395 					 &lm90_emergency_group);
1396 		if (err)
1397 			goto exit_remove_files;
1398 	}
1399 	if (data->flags & LM90_HAVE_EMERGENCY_ALARM) {
1400 		err = sysfs_create_group(&new_client->dev.kobj,
1401 					 &lm90_emergency_alarm_group);
1402 		if (err)
1403 			goto exit_remove_files;
1404 	}
1405 	if (data->flags & LM90_HAVE_TEMP3) {
1406 		err = sysfs_create_group(&new_client->dev.kobj,
1407 					 &lm90_temp3_group);
1408 		if (err)
1409 			goto exit_remove_files;
1410 	}
1411 
1412 	data->hwmon_dev = hwmon_device_register(&new_client->dev);
1413 	if (IS_ERR(data->hwmon_dev)) {
1414 		err = PTR_ERR(data->hwmon_dev);
1415 		goto exit_remove_files;
1416 	}
1417 
1418 	return 0;
1419 
1420 exit_remove_files:
1421 	lm90_remove_files(new_client, data);
1422 exit_free:
1423 	kfree(data);
1424 exit:
1425 	return err;
1426 }
1427 
1428 static int lm90_remove(struct i2c_client *client)
1429 {
1430 	struct lm90_data *data = i2c_get_clientdata(client);
1431 
1432 	hwmon_device_unregister(data->hwmon_dev);
1433 	lm90_remove_files(client, data);
1434 
1435 	/* Restore initial configuration */
1436 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
1437 				  data->convrate_orig);
1438 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
1439 				  data->config_orig);
1440 
1441 	kfree(data);
1442 	return 0;
1443 }
1444 
1445 static void lm90_alert(struct i2c_client *client, unsigned int flag)
1446 {
1447 	struct lm90_data *data = i2c_get_clientdata(client);
1448 	u8 config, alarms, alarms2 = 0;
1449 
1450 	lm90_read_reg(client, LM90_REG_R_STATUS, &alarms);
1451 
1452 	if (data->kind == max6696)
1453 		lm90_read_reg(client, MAX6696_REG_R_STATUS2, &alarms2);
1454 
1455 	if ((alarms & 0x7f) == 0 && (alarms2 & 0xfe) == 0) {
1456 		dev_info(&client->dev, "Everything OK\n");
1457 	} else {
1458 		if (alarms & 0x61)
1459 			dev_warn(&client->dev,
1460 				 "temp%d out of range, please check!\n", 1);
1461 		if (alarms & 0x1a)
1462 			dev_warn(&client->dev,
1463 				 "temp%d out of range, please check!\n", 2);
1464 		if (alarms & 0x04)
1465 			dev_warn(&client->dev,
1466 				 "temp%d diode open, please check!\n", 2);
1467 
1468 		if (alarms2 & 0x18)
1469 			dev_warn(&client->dev,
1470 				 "temp%d out of range, please check!\n", 3);
1471 
1472 		/* Disable ALERT# output, because these chips don't implement
1473 		  SMBus alert correctly; they should only hold the alert line
1474 		  low briefly. */
1475 		if ((data->flags & LM90_HAVE_BROKEN_ALERT)
1476 		 && (alarms & data->alert_alarms)) {
1477 			dev_dbg(&client->dev, "Disabling ALERT#\n");
1478 			lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
1479 			i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
1480 						  config | 0x80);
1481 		}
1482 	}
1483 }
1484 
1485 static struct i2c_driver lm90_driver = {
1486 	.class		= I2C_CLASS_HWMON,
1487 	.driver = {
1488 		.name	= "lm90",
1489 	},
1490 	.probe		= lm90_probe,
1491 	.remove		= lm90_remove,
1492 	.alert		= lm90_alert,
1493 	.id_table	= lm90_id,
1494 	.detect		= lm90_detect,
1495 	.address_list	= normal_i2c,
1496 };
1497 
1498 static int __init sensors_lm90_init(void)
1499 {
1500 	return i2c_add_driver(&lm90_driver);
1501 }
1502 
1503 static void __exit sensors_lm90_exit(void)
1504 {
1505 	i2c_del_driver(&lm90_driver);
1506 }
1507 
1508 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
1509 MODULE_DESCRIPTION("LM90/ADM1032 driver");
1510 MODULE_LICENSE("GPL");
1511 
1512 module_init(sensors_lm90_init);
1513 module_exit(sensors_lm90_exit);
1514