xref: /openbmc/linux/drivers/hwmon/lm90.c (revision 565d76cb)
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 the ADT7461 chip from Analog Devices.
53  * It's supported in both compatibility and extended mode. It is mostly
54  * compatible with LM90 except for a data format difference for the
55  * 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, MAX6649, MAX6657,
92  * MAX6658 and W83L771 have address 0x4c.
93  * ADM1032-2, ADT7461-2, LM89-1, LM99-1 and MAX6646 have address 0x4d.
94  * MAX6647 has address 0x4e.
95  * MAX6659 can have address 0x4c, 0x4d or 0x4e.
96  * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
97  * 0x4c, 0x4d or 0x4e.
98  */
99 
100 static const unsigned short normal_i2c[] = {
101 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
102 
103 enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
104 	max6646, w83l771, max6696 };
105 
106 /*
107  * The LM90 registers
108  */
109 
110 #define LM90_REG_R_MAN_ID		0xFE
111 #define LM90_REG_R_CHIP_ID		0xFF
112 #define LM90_REG_R_CONFIG1		0x03
113 #define LM90_REG_W_CONFIG1		0x09
114 #define LM90_REG_R_CONFIG2		0xBF
115 #define LM90_REG_W_CONFIG2		0xBF
116 #define LM90_REG_R_CONVRATE		0x04
117 #define LM90_REG_W_CONVRATE		0x0A
118 #define LM90_REG_R_STATUS		0x02
119 #define LM90_REG_R_LOCAL_TEMP		0x00
120 #define LM90_REG_R_LOCAL_HIGH		0x05
121 #define LM90_REG_W_LOCAL_HIGH		0x0B
122 #define LM90_REG_R_LOCAL_LOW		0x06
123 #define LM90_REG_W_LOCAL_LOW		0x0C
124 #define LM90_REG_R_LOCAL_CRIT		0x20
125 #define LM90_REG_W_LOCAL_CRIT		0x20
126 #define LM90_REG_R_REMOTE_TEMPH		0x01
127 #define LM90_REG_R_REMOTE_TEMPL		0x10
128 #define LM90_REG_R_REMOTE_OFFSH		0x11
129 #define LM90_REG_W_REMOTE_OFFSH		0x11
130 #define LM90_REG_R_REMOTE_OFFSL		0x12
131 #define LM90_REG_W_REMOTE_OFFSL		0x12
132 #define LM90_REG_R_REMOTE_HIGHH		0x07
133 #define LM90_REG_W_REMOTE_HIGHH		0x0D
134 #define LM90_REG_R_REMOTE_HIGHL		0x13
135 #define LM90_REG_W_REMOTE_HIGHL		0x13
136 #define LM90_REG_R_REMOTE_LOWH		0x08
137 #define LM90_REG_W_REMOTE_LOWH		0x0E
138 #define LM90_REG_R_REMOTE_LOWL		0x14
139 #define LM90_REG_W_REMOTE_LOWL		0x14
140 #define LM90_REG_R_REMOTE_CRIT		0x19
141 #define LM90_REG_W_REMOTE_CRIT		0x19
142 #define LM90_REG_R_TCRIT_HYST		0x21
143 #define LM90_REG_W_TCRIT_HYST		0x21
144 
145 /* MAX6646/6647/6649/6657/6658/6659/6695/6696 registers */
146 
147 #define MAX6657_REG_R_LOCAL_TEMPL	0x11
148 #define MAX6696_REG_R_STATUS2		0x12
149 #define MAX6659_REG_R_REMOTE_EMERG	0x16
150 #define MAX6659_REG_W_REMOTE_EMERG	0x16
151 #define MAX6659_REG_R_LOCAL_EMERG	0x17
152 #define MAX6659_REG_W_LOCAL_EMERG	0x17
153 
154 #define LM90_DEF_CONVRATE_RVAL	6	/* Def conversion rate register value */
155 #define LM90_MAX_CONVRATE_MS	16000	/* Maximum conversion rate in ms */
156 
157 /*
158  * Device flags
159  */
160 #define LM90_FLAG_ADT7461_EXT	(1 << 0) /* ADT7461 extended mode	*/
161 /* Device features */
162 #define LM90_HAVE_OFFSET	(1 << 1) /* temperature offset register	*/
163 #define LM90_HAVE_LOCAL_EXT	(1 << 2) /* extended local temperature	*/
164 #define LM90_HAVE_REM_LIMIT_EXT	(1 << 3) /* extended remote limit	*/
165 #define LM90_HAVE_EMERGENCY	(1 << 4) /* 3rd upper (emergency) limit	*/
166 #define LM90_HAVE_EMERGENCY_ALARM (1 << 5)/* emergency alarm		*/
167 #define LM90_HAVE_TEMP3		(1 << 6) /* 3rd temperature sensor	*/
168 #define LM90_HAVE_BROKEN_ALERT	(1 << 7) /* Broken alert		*/
169 
170 /*
171  * Driver data (common to all clients)
172  */
173 
174 static const struct i2c_device_id lm90_id[] = {
175 	{ "adm1032", adm1032 },
176 	{ "adt7461", adt7461 },
177 	{ "lm90", lm90 },
178 	{ "lm86", lm86 },
179 	{ "lm89", lm86 },
180 	{ "lm99", lm99 },
181 	{ "max6646", max6646 },
182 	{ "max6647", max6646 },
183 	{ "max6649", max6646 },
184 	{ "max6657", max6657 },
185 	{ "max6658", max6657 },
186 	{ "max6659", max6659 },
187 	{ "max6680", max6680 },
188 	{ "max6681", max6680 },
189 	{ "max6695", max6696 },
190 	{ "max6696", max6696 },
191 	{ "w83l771", w83l771 },
192 	{ }
193 };
194 MODULE_DEVICE_TABLE(i2c, lm90_id);
195 
196 /*
197  * chip type specific parameters
198  */
199 struct lm90_params {
200 	u32 flags;		/* Capabilities */
201 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
202 				/* Upper 8 bits for max6695/96 */
203 	u8 max_convrate;	/* Maximum conversion rate register value */
204 };
205 
206 static const struct lm90_params lm90_params[] = {
207 	[adm1032] = {
208 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
209 		  | LM90_HAVE_BROKEN_ALERT,
210 		.alert_alarms = 0x7c,
211 		.max_convrate = 10,
212 	},
213 	[adt7461] = {
214 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
215 		  | LM90_HAVE_BROKEN_ALERT,
216 		.alert_alarms = 0x7c,
217 		.max_convrate = 10,
218 	},
219 	[lm86] = {
220 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
221 		.alert_alarms = 0x7b,
222 		.max_convrate = 9,
223 	},
224 	[lm90] = {
225 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
226 		.alert_alarms = 0x7b,
227 		.max_convrate = 9,
228 	},
229 	[lm99] = {
230 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
231 		.alert_alarms = 0x7b,
232 		.max_convrate = 9,
233 	},
234 	[max6646] = {
235 		.flags = LM90_HAVE_LOCAL_EXT,
236 		.alert_alarms = 0x7c,
237 		.max_convrate = 6,
238 	},
239 	[max6657] = {
240 		.flags = LM90_HAVE_LOCAL_EXT,
241 		.alert_alarms = 0x7c,
242 		.max_convrate = 8,
243 	},
244 	[max6659] = {
245 		.flags = LM90_HAVE_LOCAL_EXT | LM90_HAVE_EMERGENCY,
246 		.alert_alarms = 0x7c,
247 		.max_convrate = 8,
248 	},
249 	[max6680] = {
250 		.flags = LM90_HAVE_OFFSET,
251 		.alert_alarms = 0x7c,
252 		.max_convrate = 7,
253 	},
254 	[max6696] = {
255 		.flags = LM90_HAVE_LOCAL_EXT | LM90_HAVE_EMERGENCY
256 		  | LM90_HAVE_EMERGENCY_ALARM | LM90_HAVE_TEMP3,
257 		.alert_alarms = 0x187c,
258 		.max_convrate = 6,
259 	},
260 	[w83l771] = {
261 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
262 		.alert_alarms = 0x7c,
263 		.max_convrate = 8,
264 	},
265 };
266 
267 /*
268  * Client data (each client gets its own)
269  */
270 
271 struct lm90_data {
272 	struct device *hwmon_dev;
273 	struct mutex update_lock;
274 	char valid; /* zero until following fields are valid */
275 	unsigned long last_updated; /* in jiffies */
276 	int kind;
277 	u32 flags;
278 
279 	int update_interval;	/* in milliseconds */
280 
281 	u8 config_orig;		/* Original configuration register value */
282 	u8 convrate_orig;	/* Original conversion rate register value */
283 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
284 				/* Upper 8 bits for max6695/96 */
285 	u8 max_convrate;	/* Maximum conversion rate */
286 
287 	/* registers values */
288 	s8 temp8[8];	/* 0: local low limit
289 			   1: local high limit
290 			   2: local critical limit
291 			   3: remote critical limit
292 			   4: local emergency limit (max6659 and max6695/96)
293 			   5: remote emergency limit (max6659 and max6695/96)
294 			   6: remote 2 critical limit (max6695/96 only)
295 			   7: remote 2 emergency limit (max6695/96 only) */
296 	s16 temp11[8];	/* 0: remote input
297 			   1: remote low limit
298 			   2: remote high limit
299 			   3: remote offset (except max6646, max6657/58/59,
300 					     and max6695/96)
301 			   4: local input
302 			   5: remote 2 input (max6695/96 only)
303 			   6: remote 2 low limit (max6695/96 only)
304 			   7: remote 2 high limit (ma6695/96 only) */
305 	u8 temp_hyst;
306 	u16 alarms; /* bitvector (upper 8 bits for max6695/96) */
307 };
308 
309 /*
310  * Support functions
311  */
312 
313 /*
314  * The ADM1032 supports PEC but not on write byte transactions, so we need
315  * to explicitly ask for a transaction without PEC.
316  */
317 static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value)
318 {
319 	return i2c_smbus_xfer(client->adapter, client->addr,
320 			      client->flags & ~I2C_CLIENT_PEC,
321 			      I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
322 }
323 
324 /*
325  * It is assumed that client->update_lock is held (unless we are in
326  * detection or initialization steps). This matters when PEC is enabled,
327  * because we don't want the address pointer to change between the write
328  * byte and the read byte transactions.
329  */
330 static int lm90_read_reg(struct i2c_client *client, u8 reg, u8 *value)
331 {
332 	int err;
333 
334 	if (client->flags & I2C_CLIENT_PEC) {
335 		err = adm1032_write_byte(client, reg);
336 		if (err >= 0)
337 			err = i2c_smbus_read_byte(client);
338 	} else
339 		err = i2c_smbus_read_byte_data(client, reg);
340 
341 	if (err < 0) {
342 		dev_warn(&client->dev, "Register %#02x read failed (%d)\n",
343 			 reg, err);
344 		return err;
345 	}
346 	*value = err;
347 
348 	return 0;
349 }
350 
351 static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl, u16 *value)
352 {
353 	int err;
354 	u8 oldh, newh, l;
355 
356 	/*
357 	 * There is a trick here. We have to read two registers to have the
358 	 * sensor temperature, but we have to beware a conversion could occur
359 	 * inbetween the readings. The datasheet says we should either use
360 	 * the one-shot conversion register, which we don't want to do
361 	 * (disables hardware monitoring) or monitor the busy bit, which is
362 	 * impossible (we can't read the values and monitor that bit at the
363 	 * exact same time). So the solution used here is to read the high
364 	 * byte once, then the low byte, then the high byte again. If the new
365 	 * high byte matches the old one, then we have a valid reading. Else
366 	 * we have to read the low byte again, and now we believe we have a
367 	 * correct reading.
368 	 */
369 	if ((err = lm90_read_reg(client, regh, &oldh))
370 	 || (err = lm90_read_reg(client, regl, &l))
371 	 || (err = lm90_read_reg(client, regh, &newh)))
372 		return err;
373 	if (oldh != newh) {
374 		err = lm90_read_reg(client, regl, &l);
375 		if (err)
376 			return err;
377 	}
378 	*value = (newh << 8) | l;
379 
380 	return 0;
381 }
382 
383 /*
384  * client->update_lock must be held when calling this function (unless we are
385  * in detection or initialization steps), and while a remote channel other
386  * than channel 0 is selected. Also, calling code must make sure to re-select
387  * external channel 0 before releasing the lock. This is necessary because
388  * various registers have different meanings as a result of selecting a
389  * non-default remote channel.
390  */
391 static inline void lm90_select_remote_channel(struct i2c_client *client,
392 					      struct lm90_data *data,
393 					      int channel)
394 {
395 	u8 config;
396 
397 	if (data->kind == max6696) {
398 		lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
399 		config &= ~0x08;
400 		if (channel)
401 			config |= 0x08;
402 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
403 					  config);
404 	}
405 }
406 
407 /*
408  * Set conversion rate.
409  * client->update_lock must be held when calling this function (unless we are
410  * in detection or initialization steps).
411  */
412 static void lm90_set_convrate(struct i2c_client *client, struct lm90_data *data,
413 			      unsigned int interval)
414 {
415 	int i;
416 	unsigned int update_interval;
417 
418 	/* Shift calculations to avoid rounding errors */
419 	interval <<= 6;
420 
421 	/* find the nearest update rate */
422 	for (i = 0, update_interval = LM90_MAX_CONVRATE_MS << 6;
423 	     i < data->max_convrate; i++, update_interval >>= 1)
424 		if (interval >= update_interval * 3 / 4)
425 			break;
426 
427 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, i);
428 	data->update_interval = DIV_ROUND_CLOSEST(update_interval, 64);
429 }
430 
431 static struct lm90_data *lm90_update_device(struct device *dev)
432 {
433 	struct i2c_client *client = to_i2c_client(dev);
434 	struct lm90_data *data = i2c_get_clientdata(client);
435 	unsigned long next_update;
436 
437 	mutex_lock(&data->update_lock);
438 
439 	next_update = data->last_updated
440 	  + msecs_to_jiffies(data->update_interval) + 1;
441 	if (time_after(jiffies, next_update) || !data->valid) {
442 		u8 h, l;
443 		u8 alarms;
444 
445 		dev_dbg(&client->dev, "Updating lm90 data.\n");
446 		lm90_read_reg(client, LM90_REG_R_LOCAL_LOW, &data->temp8[0]);
447 		lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH, &data->temp8[1]);
448 		lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT, &data->temp8[2]);
449 		lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[3]);
450 		lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
451 
452 		if (data->flags & LM90_HAVE_LOCAL_EXT) {
453 			lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
454 				    MAX6657_REG_R_LOCAL_TEMPL,
455 				    &data->temp11[4]);
456 		} else {
457 			if (lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP,
458 					  &h) == 0)
459 				data->temp11[4] = h << 8;
460 		}
461 		lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
462 			    LM90_REG_R_REMOTE_TEMPL, &data->temp11[0]);
463 
464 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h) == 0) {
465 			data->temp11[1] = h << 8;
466 			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
467 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL,
468 					  &l) == 0)
469 				data->temp11[1] |= l;
470 		}
471 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h) == 0) {
472 			data->temp11[2] = h << 8;
473 			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
474 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL,
475 					  &l) == 0)
476 				data->temp11[2] |= l;
477 		}
478 
479 		if (data->flags & LM90_HAVE_OFFSET) {
480 			if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
481 					  &h) == 0
482 			 && lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,
483 					  &l) == 0)
484 				data->temp11[3] = (h << 8) | l;
485 		}
486 		if (data->flags & LM90_HAVE_EMERGENCY) {
487 			lm90_read_reg(client, MAX6659_REG_R_LOCAL_EMERG,
488 				      &data->temp8[4]);
489 			lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
490 				      &data->temp8[5]);
491 		}
492 		lm90_read_reg(client, LM90_REG_R_STATUS, &alarms);
493 		data->alarms = alarms;	/* save as 16 bit value */
494 
495 		if (data->kind == max6696) {
496 			lm90_select_remote_channel(client, data, 1);
497 			lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT,
498 				      &data->temp8[6]);
499 			lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
500 				      &data->temp8[7]);
501 			lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
502 				    LM90_REG_R_REMOTE_TEMPL, &data->temp11[5]);
503 			if (!lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h))
504 				data->temp11[6] = h << 8;
505 			if (!lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h))
506 				data->temp11[7] = h << 8;
507 			lm90_select_remote_channel(client, data, 0);
508 
509 			if (!lm90_read_reg(client, MAX6696_REG_R_STATUS2,
510 					   &alarms))
511 				data->alarms |= alarms << 8;
512 		}
513 
514 		/* Re-enable ALERT# output if it was originally enabled and
515 		 * relevant alarms are all clear */
516 		if ((data->config_orig & 0x80) == 0
517 		 && (data->alarms & data->alert_alarms) == 0) {
518 			u8 config;
519 
520 			lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
521 			if (config & 0x80) {
522 				dev_dbg(&client->dev, "Re-enabling ALERT#\n");
523 				i2c_smbus_write_byte_data(client,
524 							  LM90_REG_W_CONFIG1,
525 							  config & ~0x80);
526 			}
527 		}
528 
529 		data->last_updated = jiffies;
530 		data->valid = 1;
531 	}
532 
533 	mutex_unlock(&data->update_lock);
534 
535 	return data;
536 }
537 
538 /*
539  * Conversions
540  * For local temperatures and limits, critical limits and the hysteresis
541  * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
542  * For remote temperatures and limits, it uses signed 11-bit values with
543  * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.  Some
544  * Maxim chips use unsigned values.
545  */
546 
547 static inline int temp_from_s8(s8 val)
548 {
549 	return val * 1000;
550 }
551 
552 static inline int temp_from_u8(u8 val)
553 {
554 	return val * 1000;
555 }
556 
557 static inline int temp_from_s16(s16 val)
558 {
559 	return val / 32 * 125;
560 }
561 
562 static inline int temp_from_u16(u16 val)
563 {
564 	return val / 32 * 125;
565 }
566 
567 static s8 temp_to_s8(long val)
568 {
569 	if (val <= -128000)
570 		return -128;
571 	if (val >= 127000)
572 		return 127;
573 	if (val < 0)
574 		return (val - 500) / 1000;
575 	return (val + 500) / 1000;
576 }
577 
578 static u8 temp_to_u8(long val)
579 {
580 	if (val <= 0)
581 		return 0;
582 	if (val >= 255000)
583 		return 255;
584 	return (val + 500) / 1000;
585 }
586 
587 static s16 temp_to_s16(long val)
588 {
589 	if (val <= -128000)
590 		return 0x8000;
591 	if (val >= 127875)
592 		return 0x7FE0;
593 	if (val < 0)
594 		return (val - 62) / 125 * 32;
595 	return (val + 62) / 125 * 32;
596 }
597 
598 static u8 hyst_to_reg(long val)
599 {
600 	if (val <= 0)
601 		return 0;
602 	if (val >= 30500)
603 		return 31;
604 	return (val + 500) / 1000;
605 }
606 
607 /*
608  * ADT7461 in compatibility mode is almost identical to LM90 except that
609  * attempts to write values that are outside the range 0 < temp < 127 are
610  * treated as the boundary value.
611  *
612  * ADT7461 in "extended mode" operation uses unsigned integers offset by
613  * 64 (e.g., 0 -> -64 degC).  The range is restricted to -64..191 degC.
614  */
615 static inline int temp_from_u8_adt7461(struct lm90_data *data, u8 val)
616 {
617 	if (data->flags & LM90_FLAG_ADT7461_EXT)
618 		return (val - 64) * 1000;
619 	else
620 		return temp_from_s8(val);
621 }
622 
623 static inline int temp_from_u16_adt7461(struct lm90_data *data, u16 val)
624 {
625 	if (data->flags & LM90_FLAG_ADT7461_EXT)
626 		return (val - 0x4000) / 64 * 250;
627 	else
628 		return temp_from_s16(val);
629 }
630 
631 static u8 temp_to_u8_adt7461(struct lm90_data *data, long val)
632 {
633 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
634 		if (val <= -64000)
635 			return 0;
636 		if (val >= 191000)
637 			return 0xFF;
638 		return (val + 500 + 64000) / 1000;
639 	} else {
640 		if (val <= 0)
641 			return 0;
642 		if (val >= 127000)
643 			return 127;
644 		return (val + 500) / 1000;
645 	}
646 }
647 
648 static u16 temp_to_u16_adt7461(struct lm90_data *data, long val)
649 {
650 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
651 		if (val <= -64000)
652 			return 0;
653 		if (val >= 191750)
654 			return 0xFFC0;
655 		return (val + 64000 + 125) / 250 * 64;
656 	} else {
657 		if (val <= 0)
658 			return 0;
659 		if (val >= 127750)
660 			return 0x7FC0;
661 		return (val + 125) / 250 * 64;
662 	}
663 }
664 
665 /*
666  * Sysfs stuff
667  */
668 
669 static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
670 			  char *buf)
671 {
672 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
673 	struct lm90_data *data = lm90_update_device(dev);
674 	int temp;
675 
676 	if (data->kind == adt7461)
677 		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
678 	else if (data->kind == max6646)
679 		temp = temp_from_u8(data->temp8[attr->index]);
680 	else
681 		temp = temp_from_s8(data->temp8[attr->index]);
682 
683 	/* +16 degrees offset for temp2 for the LM99 */
684 	if (data->kind == lm99 && attr->index == 3)
685 		temp += 16000;
686 
687 	return sprintf(buf, "%d\n", temp);
688 }
689 
690 static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
691 			 const char *buf, size_t count)
692 {
693 	static const u8 reg[8] = {
694 		LM90_REG_W_LOCAL_LOW,
695 		LM90_REG_W_LOCAL_HIGH,
696 		LM90_REG_W_LOCAL_CRIT,
697 		LM90_REG_W_REMOTE_CRIT,
698 		MAX6659_REG_W_LOCAL_EMERG,
699 		MAX6659_REG_W_REMOTE_EMERG,
700 		LM90_REG_W_REMOTE_CRIT,
701 		MAX6659_REG_W_REMOTE_EMERG,
702 	};
703 
704 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
705 	struct i2c_client *client = to_i2c_client(dev);
706 	struct lm90_data *data = i2c_get_clientdata(client);
707 	int nr = attr->index;
708 	long val;
709 	int err;
710 
711 	err = strict_strtol(buf, 10, &val);
712 	if (err < 0)
713 		return err;
714 
715 	/* +16 degrees offset for temp2 for the LM99 */
716 	if (data->kind == lm99 && attr->index == 3)
717 		val -= 16000;
718 
719 	mutex_lock(&data->update_lock);
720 	if (data->kind == adt7461)
721 		data->temp8[nr] = temp_to_u8_adt7461(data, val);
722 	else if (data->kind == max6646)
723 		data->temp8[nr] = temp_to_u8(val);
724 	else
725 		data->temp8[nr] = temp_to_s8(val);
726 
727 	lm90_select_remote_channel(client, data, nr >= 6);
728 	i2c_smbus_write_byte_data(client, reg[nr], data->temp8[nr]);
729 	lm90_select_remote_channel(client, data, 0);
730 
731 	mutex_unlock(&data->update_lock);
732 	return count;
733 }
734 
735 static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
736 			   char *buf)
737 {
738 	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
739 	struct lm90_data *data = lm90_update_device(dev);
740 	int temp;
741 
742 	if (data->kind == adt7461)
743 		temp = temp_from_u16_adt7461(data, data->temp11[attr->index]);
744 	else if (data->kind == max6646)
745 		temp = temp_from_u16(data->temp11[attr->index]);
746 	else
747 		temp = temp_from_s16(data->temp11[attr->index]);
748 
749 	/* +16 degrees offset for temp2 for the LM99 */
750 	if (data->kind == lm99 &&  attr->index <= 2)
751 		temp += 16000;
752 
753 	return sprintf(buf, "%d\n", temp);
754 }
755 
756 static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
757 			  const char *buf, size_t count)
758 {
759 	struct {
760 		u8 high;
761 		u8 low;
762 		int channel;
763 	} reg[5] = {
764 		{ LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL, 0 },
765 		{ LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 0 },
766 		{ LM90_REG_W_REMOTE_OFFSH, LM90_REG_W_REMOTE_OFFSL, 0 },
767 		{ LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL, 1 },
768 		{ LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 1 }
769 	};
770 
771 	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
772 	struct i2c_client *client = to_i2c_client(dev);
773 	struct lm90_data *data = i2c_get_clientdata(client);
774 	int nr = attr->nr;
775 	int index = attr->index;
776 	long val;
777 	int err;
778 
779 	err = strict_strtol(buf, 10, &val);
780 	if (err < 0)
781 		return err;
782 
783 	/* +16 degrees offset for temp2 for the LM99 */
784 	if (data->kind == lm99 && index <= 2)
785 		val -= 16000;
786 
787 	mutex_lock(&data->update_lock);
788 	if (data->kind == adt7461)
789 		data->temp11[index] = temp_to_u16_adt7461(data, val);
790 	else if (data->kind == max6646)
791 		data->temp11[index] = temp_to_u8(val) << 8;
792 	else if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
793 		data->temp11[index] = temp_to_s16(val);
794 	else
795 		data->temp11[index] = temp_to_s8(val) << 8;
796 
797 	lm90_select_remote_channel(client, data, reg[nr].channel);
798 	i2c_smbus_write_byte_data(client, reg[nr].high,
799 				  data->temp11[index] >> 8);
800 	if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
801 		i2c_smbus_write_byte_data(client, reg[nr].low,
802 					  data->temp11[index] & 0xff);
803 	lm90_select_remote_channel(client, data, 0);
804 
805 	mutex_unlock(&data->update_lock);
806 	return count;
807 }
808 
809 static ssize_t show_temphyst(struct device *dev,
810 			     struct device_attribute *devattr,
811 			     char *buf)
812 {
813 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
814 	struct lm90_data *data = lm90_update_device(dev);
815 	int temp;
816 
817 	if (data->kind == adt7461)
818 		temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
819 	else if (data->kind == max6646)
820 		temp = temp_from_u8(data->temp8[attr->index]);
821 	else
822 		temp = temp_from_s8(data->temp8[attr->index]);
823 
824 	/* +16 degrees offset for temp2 for the LM99 */
825 	if (data->kind == lm99 && attr->index == 3)
826 		temp += 16000;
827 
828 	return sprintf(buf, "%d\n", temp - temp_from_s8(data->temp_hyst));
829 }
830 
831 static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
832 			    const char *buf, size_t count)
833 {
834 	struct i2c_client *client = to_i2c_client(dev);
835 	struct lm90_data *data = i2c_get_clientdata(client);
836 	long val;
837 	int err;
838 	int temp;
839 
840 	err = strict_strtol(buf, 10, &val);
841 	if (err < 0)
842 		return err;
843 
844 	mutex_lock(&data->update_lock);
845 	if (data->kind == adt7461)
846 		temp = temp_from_u8_adt7461(data, data->temp8[2]);
847 	else if (data->kind == max6646)
848 		temp = temp_from_u8(data->temp8[2]);
849 	else
850 		temp = temp_from_s8(data->temp8[2]);
851 
852 	data->temp_hyst = hyst_to_reg(temp - val);
853 	i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
854 				  data->temp_hyst);
855 	mutex_unlock(&data->update_lock);
856 	return count;
857 }
858 
859 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
860 			   char *buf)
861 {
862 	struct lm90_data *data = lm90_update_device(dev);
863 	return sprintf(buf, "%d\n", data->alarms);
864 }
865 
866 static ssize_t show_alarm(struct device *dev, struct device_attribute
867 			  *devattr, char *buf)
868 {
869 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
870 	struct lm90_data *data = lm90_update_device(dev);
871 	int bitnr = attr->index;
872 
873 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
874 }
875 
876 static ssize_t show_update_interval(struct device *dev,
877 				    struct device_attribute *attr, char *buf)
878 {
879 	struct lm90_data *data = dev_get_drvdata(dev);
880 
881 	return sprintf(buf, "%u\n", data->update_interval);
882 }
883 
884 static ssize_t set_update_interval(struct device *dev,
885 				   struct device_attribute *attr,
886 				   const char *buf, size_t count)
887 {
888 	struct i2c_client *client = to_i2c_client(dev);
889 	struct lm90_data *data = i2c_get_clientdata(client);
890 	unsigned long val;
891 	int err;
892 
893 	err = strict_strtoul(buf, 10, &val);
894 	if (err)
895 		return err;
896 
897 	mutex_lock(&data->update_lock);
898 	lm90_set_convrate(client, data, val);
899 	mutex_unlock(&data->update_lock);
900 
901 	return count;
902 }
903 
904 static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp11, NULL, 0, 4);
905 static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp11, NULL, 0, 0);
906 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
907 	set_temp8, 0);
908 static SENSOR_DEVICE_ATTR_2(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
909 	set_temp11, 0, 1);
910 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
911 	set_temp8, 1);
912 static SENSOR_DEVICE_ATTR_2(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
913 	set_temp11, 1, 2);
914 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
915 	set_temp8, 2);
916 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
917 	set_temp8, 3);
918 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
919 	set_temphyst, 2);
920 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 3);
921 static SENSOR_DEVICE_ATTR_2(temp2_offset, S_IWUSR | S_IRUGO, show_temp11,
922 	set_temp11, 2, 3);
923 
924 /* Individual alarm files */
925 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
926 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
927 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
928 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
929 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
930 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 5);
931 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
932 /* Raw alarm file for compatibility */
933 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
934 
935 static DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR, show_update_interval,
936 		   set_update_interval);
937 
938 static struct attribute *lm90_attributes[] = {
939 	&sensor_dev_attr_temp1_input.dev_attr.attr,
940 	&sensor_dev_attr_temp2_input.dev_attr.attr,
941 	&sensor_dev_attr_temp1_min.dev_attr.attr,
942 	&sensor_dev_attr_temp2_min.dev_attr.attr,
943 	&sensor_dev_attr_temp1_max.dev_attr.attr,
944 	&sensor_dev_attr_temp2_max.dev_attr.attr,
945 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
946 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
947 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
948 	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
949 
950 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
951 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
952 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
953 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
954 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
955 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
956 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
957 	&dev_attr_alarms.attr,
958 	&dev_attr_update_interval.attr,
959 	NULL
960 };
961 
962 static const struct attribute_group lm90_group = {
963 	.attrs = lm90_attributes,
964 };
965 
966 /*
967  * Additional attributes for devices with emergency sensors
968  */
969 static SENSOR_DEVICE_ATTR(temp1_emergency, S_IWUSR | S_IRUGO, show_temp8,
970 	set_temp8, 4);
971 static SENSOR_DEVICE_ATTR(temp2_emergency, S_IWUSR | S_IRUGO, show_temp8,
972 	set_temp8, 5);
973 static SENSOR_DEVICE_ATTR(temp1_emergency_hyst, S_IRUGO, show_temphyst,
974 			  NULL, 4);
975 static SENSOR_DEVICE_ATTR(temp2_emergency_hyst, S_IRUGO, show_temphyst,
976 			  NULL, 5);
977 
978 static struct attribute *lm90_emergency_attributes[] = {
979 	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
980 	&sensor_dev_attr_temp2_emergency.dev_attr.attr,
981 	&sensor_dev_attr_temp1_emergency_hyst.dev_attr.attr,
982 	&sensor_dev_attr_temp2_emergency_hyst.dev_attr.attr,
983 	NULL
984 };
985 
986 static const struct attribute_group lm90_emergency_group = {
987 	.attrs = lm90_emergency_attributes,
988 };
989 
990 static SENSOR_DEVICE_ATTR(temp1_emergency_alarm, S_IRUGO, show_alarm, NULL, 15);
991 static SENSOR_DEVICE_ATTR(temp2_emergency_alarm, S_IRUGO, show_alarm, NULL, 13);
992 
993 static struct attribute *lm90_emergency_alarm_attributes[] = {
994 	&sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
995 	&sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
996 	NULL
997 };
998 
999 static const struct attribute_group lm90_emergency_alarm_group = {
1000 	.attrs = lm90_emergency_alarm_attributes,
1001 };
1002 
1003 /*
1004  * Additional attributes for devices with 3 temperature sensors
1005  */
1006 static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp11, NULL, 0, 5);
1007 static SENSOR_DEVICE_ATTR_2(temp3_min, S_IWUSR | S_IRUGO, show_temp11,
1008 	set_temp11, 3, 6);
1009 static SENSOR_DEVICE_ATTR_2(temp3_max, S_IWUSR | S_IRUGO, show_temp11,
1010 	set_temp11, 4, 7);
1011 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp8,
1012 	set_temp8, 6);
1013 static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO, show_temphyst, NULL, 6);
1014 static SENSOR_DEVICE_ATTR(temp3_emergency, S_IWUSR | S_IRUGO, show_temp8,
1015 	set_temp8, 7);
1016 static SENSOR_DEVICE_ATTR(temp3_emergency_hyst, S_IRUGO, show_temphyst,
1017 			  NULL, 7);
1018 
1019 static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
1020 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 10);
1021 static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_alarm, NULL, 11);
1022 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 12);
1023 static SENSOR_DEVICE_ATTR(temp3_emergency_alarm, S_IRUGO, show_alarm, NULL, 14);
1024 
1025 static struct attribute *lm90_temp3_attributes[] = {
1026 	&sensor_dev_attr_temp3_input.dev_attr.attr,
1027 	&sensor_dev_attr_temp3_min.dev_attr.attr,
1028 	&sensor_dev_attr_temp3_max.dev_attr.attr,
1029 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
1030 	&sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
1031 	&sensor_dev_attr_temp3_emergency.dev_attr.attr,
1032 	&sensor_dev_attr_temp3_emergency_hyst.dev_attr.attr,
1033 
1034 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
1035 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
1036 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
1037 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
1038 	&sensor_dev_attr_temp3_emergency_alarm.dev_attr.attr,
1039 	NULL
1040 };
1041 
1042 static const struct attribute_group lm90_temp3_group = {
1043 	.attrs = lm90_temp3_attributes,
1044 };
1045 
1046 /* pec used for ADM1032 only */
1047 static ssize_t show_pec(struct device *dev, struct device_attribute *dummy,
1048 			char *buf)
1049 {
1050 	struct i2c_client *client = to_i2c_client(dev);
1051 	return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
1052 }
1053 
1054 static ssize_t set_pec(struct device *dev, struct device_attribute *dummy,
1055 		       const char *buf, size_t count)
1056 {
1057 	struct i2c_client *client = to_i2c_client(dev);
1058 	long val;
1059 	int err;
1060 
1061 	err = strict_strtol(buf, 10, &val);
1062 	if (err < 0)
1063 		return err;
1064 
1065 	switch (val) {
1066 	case 0:
1067 		client->flags &= ~I2C_CLIENT_PEC;
1068 		break;
1069 	case 1:
1070 		client->flags |= I2C_CLIENT_PEC;
1071 		break;
1072 	default:
1073 		return -EINVAL;
1074 	}
1075 
1076 	return count;
1077 }
1078 
1079 static DEVICE_ATTR(pec, S_IWUSR | S_IRUGO, show_pec, set_pec);
1080 
1081 /*
1082  * Real code
1083  */
1084 
1085 /* Return 0 if detection is successful, -ENODEV otherwise */
1086 static int lm90_detect(struct i2c_client *new_client,
1087 		       struct i2c_board_info *info)
1088 {
1089 	struct i2c_adapter *adapter = new_client->adapter;
1090 	int address = new_client->addr;
1091 	const char *name = NULL;
1092 	int man_id, chip_id, reg_config1, reg_convrate;
1093 
1094 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
1095 		return -ENODEV;
1096 
1097 	/* detection and identification */
1098 	if ((man_id = i2c_smbus_read_byte_data(new_client,
1099 						LM90_REG_R_MAN_ID)) < 0
1100 	 || (chip_id = i2c_smbus_read_byte_data(new_client,
1101 						LM90_REG_R_CHIP_ID)) < 0
1102 	 || (reg_config1 = i2c_smbus_read_byte_data(new_client,
1103 						LM90_REG_R_CONFIG1)) < 0
1104 	 || (reg_convrate = i2c_smbus_read_byte_data(new_client,
1105 						LM90_REG_R_CONVRATE)) < 0)
1106 		return -ENODEV;
1107 
1108 	if ((address == 0x4C || address == 0x4D)
1109 	 && man_id == 0x01) { /* National Semiconductor */
1110 		int reg_config2;
1111 
1112 		reg_config2 = i2c_smbus_read_byte_data(new_client,
1113 						LM90_REG_R_CONFIG2);
1114 		if (reg_config2 < 0)
1115 			return -ENODEV;
1116 
1117 		if ((reg_config1 & 0x2A) == 0x00
1118 		 && (reg_config2 & 0xF8) == 0x00
1119 		 && reg_convrate <= 0x09) {
1120 			if (address == 0x4C
1121 			 && (chip_id & 0xF0) == 0x20) { /* LM90 */
1122 				name = "lm90";
1123 			} else
1124 			if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
1125 				name = "lm99";
1126 				dev_info(&adapter->dev,
1127 					 "Assuming LM99 chip at 0x%02x\n",
1128 					 address);
1129 				dev_info(&adapter->dev,
1130 					 "If it is an LM89, instantiate it "
1131 					 "with the new_device sysfs "
1132 					 "interface\n");
1133 			} else
1134 			if (address == 0x4C
1135 			 && (chip_id & 0xF0) == 0x10) { /* LM86 */
1136 				name = "lm86";
1137 			}
1138 		}
1139 	} else
1140 	if ((address == 0x4C || address == 0x4D)
1141 	 && man_id == 0x41) { /* Analog Devices */
1142 		if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
1143 		 && (reg_config1 & 0x3F) == 0x00
1144 		 && reg_convrate <= 0x0A) {
1145 			name = "adm1032";
1146 			/* The ADM1032 supports PEC, but only if combined
1147 			   transactions are not used. */
1148 			if (i2c_check_functionality(adapter,
1149 						    I2C_FUNC_SMBUS_BYTE))
1150 				info->flags |= I2C_CLIENT_PEC;
1151 		} else
1152 		if (chip_id == 0x51 /* ADT7461 */
1153 		 && (reg_config1 & 0x1B) == 0x00
1154 		 && reg_convrate <= 0x0A) {
1155 			name = "adt7461";
1156 		}
1157 	} else
1158 	if (man_id == 0x4D) { /* Maxim */
1159 		int reg_emerg, reg_emerg2, reg_status2;
1160 
1161 		/*
1162 		 * We read MAX6659_REG_R_REMOTE_EMERG twice, and re-read
1163 		 * LM90_REG_R_MAN_ID in between. If MAX6659_REG_R_REMOTE_EMERG
1164 		 * exists, both readings will reflect the same value. Otherwise,
1165 		 * the readings will be different.
1166 		 */
1167 		if ((reg_emerg = i2c_smbus_read_byte_data(new_client,
1168 						MAX6659_REG_R_REMOTE_EMERG)) < 0
1169 		 || i2c_smbus_read_byte_data(new_client, LM90_REG_R_MAN_ID) < 0
1170 		 || (reg_emerg2 = i2c_smbus_read_byte_data(new_client,
1171 						MAX6659_REG_R_REMOTE_EMERG)) < 0
1172 		 || (reg_status2 = i2c_smbus_read_byte_data(new_client,
1173 						MAX6696_REG_R_STATUS2)) < 0)
1174 			return -ENODEV;
1175 
1176 		/*
1177 		 * The MAX6657, MAX6658 and MAX6659 do NOT have a chip_id
1178 		 * register. Reading from that address will return the last
1179 		 * read value, which in our case is those of the man_id
1180 		 * register. Likewise, the config1 register seems to lack a
1181 		 * low nibble, so the value will be those of the previous
1182 		 * read, so in our case those of the man_id register.
1183 		 * MAX6659 has a third set of upper temperature limit registers.
1184 		 * Those registers also return values on MAX6657 and MAX6658,
1185 		 * thus the only way to detect MAX6659 is by its address.
1186 		 * For this reason it will be mis-detected as MAX6657 if its
1187 		 * address is 0x4C.
1188 		 */
1189 		if (chip_id == man_id
1190 		 && (address == 0x4C || address == 0x4D || address == 0x4E)
1191 		 && (reg_config1 & 0x1F) == (man_id & 0x0F)
1192 		 && reg_convrate <= 0x09) {
1193 			if (address == 0x4C)
1194 				name = "max6657";
1195 			else
1196 				name = "max6659";
1197 		} else
1198 		/*
1199 		 * Even though MAX6695 and MAX6696 do not have a chip ID
1200 		 * register, reading it returns 0x01. Bit 4 of the config1
1201 		 * register is unused and should return zero when read. Bit 0 of
1202 		 * the status2 register is unused and should return zero when
1203 		 * read.
1204 		 *
1205 		 * MAX6695 and MAX6696 have an additional set of temperature
1206 		 * limit registers. We can detect those chips by checking if
1207 		 * one of those registers exists.
1208 		 */
1209 		if (chip_id == 0x01
1210 		 && (reg_config1 & 0x10) == 0x00
1211 		 && (reg_status2 & 0x01) == 0x00
1212 		 && reg_emerg == reg_emerg2
1213 		 && reg_convrate <= 0x07) {
1214 			name = "max6696";
1215 		} else
1216 		/*
1217 		 * The chip_id register of the MAX6680 and MAX6681 holds the
1218 		 * revision of the chip. The lowest bit of the config1 register
1219 		 * is unused and should return zero when read, so should the
1220 		 * second to last bit of config1 (software reset).
1221 		 */
1222 		if (chip_id == 0x01
1223 		 && (reg_config1 & 0x03) == 0x00
1224 		 && reg_convrate <= 0x07) {
1225 			name = "max6680";
1226 		} else
1227 		/*
1228 		 * The chip_id register of the MAX6646/6647/6649 holds the
1229 		 * revision of the chip. The lowest 6 bits of the config1
1230 		 * register are unused and should return zero when read.
1231 		 */
1232 		if (chip_id == 0x59
1233 		 && (reg_config1 & 0x3f) == 0x00
1234 		 && reg_convrate <= 0x07) {
1235 			name = "max6646";
1236 		}
1237 	} else
1238 	if (address == 0x4C
1239 	 && man_id == 0x5C) { /* Winbond/Nuvoton */
1240 		int reg_config2;
1241 
1242 		reg_config2 = i2c_smbus_read_byte_data(new_client,
1243 						LM90_REG_R_CONFIG2);
1244 		if (reg_config2 < 0)
1245 			return -ENODEV;
1246 
1247 		if ((reg_config1 & 0x2A) == 0x00
1248 		 && (reg_config2 & 0xF8) == 0x00) {
1249 			if (chip_id == 0x01 /* W83L771W/G */
1250 			 && reg_convrate <= 0x09) {
1251 				name = "w83l771";
1252 			} else
1253 			if ((chip_id & 0xFE) == 0x10 /* W83L771AWG/ASG */
1254 			 && reg_convrate <= 0x08) {
1255 				name = "w83l771";
1256 			}
1257 		}
1258 	}
1259 
1260 	if (!name) { /* identification failed */
1261 		dev_dbg(&adapter->dev,
1262 			"Unsupported chip at 0x%02x (man_id=0x%02X, "
1263 			"chip_id=0x%02X)\n", address, man_id, chip_id);
1264 		return -ENODEV;
1265 	}
1266 
1267 	strlcpy(info->type, name, I2C_NAME_SIZE);
1268 
1269 	return 0;
1270 }
1271 
1272 static void lm90_remove_files(struct i2c_client *client, struct lm90_data *data)
1273 {
1274 	if (data->flags & LM90_HAVE_TEMP3)
1275 		sysfs_remove_group(&client->dev.kobj, &lm90_temp3_group);
1276 	if (data->flags & LM90_HAVE_EMERGENCY_ALARM)
1277 		sysfs_remove_group(&client->dev.kobj,
1278 				   &lm90_emergency_alarm_group);
1279 	if (data->flags & LM90_HAVE_EMERGENCY)
1280 		sysfs_remove_group(&client->dev.kobj,
1281 				   &lm90_emergency_group);
1282 	if (data->flags & LM90_HAVE_OFFSET)
1283 		device_remove_file(&client->dev,
1284 				   &sensor_dev_attr_temp2_offset.dev_attr);
1285 	device_remove_file(&client->dev, &dev_attr_pec);
1286 	sysfs_remove_group(&client->dev.kobj, &lm90_group);
1287 }
1288 
1289 static void lm90_init_client(struct i2c_client *client)
1290 {
1291 	u8 config, convrate;
1292 	struct lm90_data *data = i2c_get_clientdata(client);
1293 
1294 	if (lm90_read_reg(client, LM90_REG_R_CONVRATE, &convrate) < 0) {
1295 		dev_warn(&client->dev, "Failed to read convrate register!\n");
1296 		convrate = LM90_DEF_CONVRATE_RVAL;
1297 	}
1298 	data->convrate_orig = convrate;
1299 
1300 	/*
1301 	 * Start the conversions.
1302 	 */
1303 	lm90_set_convrate(client, data, 500);	/* 500ms; 2Hz conversion rate */
1304 	if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) {
1305 		dev_warn(&client->dev, "Initialization failed!\n");
1306 		return;
1307 	}
1308 	data->config_orig = config;
1309 
1310 	/* Check Temperature Range Select */
1311 	if (data->kind == adt7461) {
1312 		if (config & 0x04)
1313 			data->flags |= LM90_FLAG_ADT7461_EXT;
1314 	}
1315 
1316 	/*
1317 	 * Put MAX6680/MAX8881 into extended resolution (bit 0x10,
1318 	 * 0.125 degree resolution) and range (0x08, extend range
1319 	 * to -64 degree) mode for the remote temperature sensor.
1320 	 */
1321 	if (data->kind == max6680)
1322 		config |= 0x18;
1323 
1324 	/*
1325 	 * Select external channel 0 for max6695/96
1326 	 */
1327 	if (data->kind == max6696)
1328 		config &= ~0x08;
1329 
1330 	config &= 0xBF;	/* run */
1331 	if (config != data->config_orig) /* Only write if changed */
1332 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config);
1333 }
1334 
1335 static int lm90_probe(struct i2c_client *new_client,
1336 		      const struct i2c_device_id *id)
1337 {
1338 	struct i2c_adapter *adapter = to_i2c_adapter(new_client->dev.parent);
1339 	struct lm90_data *data;
1340 	int err;
1341 
1342 	data = kzalloc(sizeof(struct lm90_data), GFP_KERNEL);
1343 	if (!data) {
1344 		err = -ENOMEM;
1345 		goto exit;
1346 	}
1347 	i2c_set_clientdata(new_client, data);
1348 	mutex_init(&data->update_lock);
1349 
1350 	/* Set the device type */
1351 	data->kind = id->driver_data;
1352 	if (data->kind == adm1032) {
1353 		if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
1354 			new_client->flags &= ~I2C_CLIENT_PEC;
1355 	}
1356 
1357 	/* Different devices have different alarm bits triggering the
1358 	 * ALERT# output */
1359 	data->alert_alarms = lm90_params[data->kind].alert_alarms;
1360 
1361 	/* Set chip capabilities */
1362 	data->flags = lm90_params[data->kind].flags;
1363 
1364 	/* Set maximum conversion rate */
1365 	data->max_convrate = lm90_params[data->kind].max_convrate;
1366 
1367 	/* Initialize the LM90 chip */
1368 	lm90_init_client(new_client);
1369 
1370 	/* Register sysfs hooks */
1371 	err = sysfs_create_group(&new_client->dev.kobj, &lm90_group);
1372 	if (err)
1373 		goto exit_free;
1374 	if (new_client->flags & I2C_CLIENT_PEC) {
1375 		err = device_create_file(&new_client->dev, &dev_attr_pec);
1376 		if (err)
1377 			goto exit_remove_files;
1378 	}
1379 	if (data->flags & LM90_HAVE_OFFSET) {
1380 		err = device_create_file(&new_client->dev,
1381 					&sensor_dev_attr_temp2_offset.dev_attr);
1382 		if (err)
1383 			goto exit_remove_files;
1384 	}
1385 	if (data->flags & LM90_HAVE_EMERGENCY) {
1386 		err = sysfs_create_group(&new_client->dev.kobj,
1387 					 &lm90_emergency_group);
1388 		if (err)
1389 			goto exit_remove_files;
1390 	}
1391 	if (data->flags & LM90_HAVE_EMERGENCY_ALARM) {
1392 		err = sysfs_create_group(&new_client->dev.kobj,
1393 					 &lm90_emergency_alarm_group);
1394 		if (err)
1395 			goto exit_remove_files;
1396 	}
1397 	if (data->flags & LM90_HAVE_TEMP3) {
1398 		err = sysfs_create_group(&new_client->dev.kobj,
1399 					 &lm90_temp3_group);
1400 		if (err)
1401 			goto exit_remove_files;
1402 	}
1403 
1404 	data->hwmon_dev = hwmon_device_register(&new_client->dev);
1405 	if (IS_ERR(data->hwmon_dev)) {
1406 		err = PTR_ERR(data->hwmon_dev);
1407 		goto exit_remove_files;
1408 	}
1409 
1410 	return 0;
1411 
1412 exit_remove_files:
1413 	lm90_remove_files(new_client, data);
1414 exit_free:
1415 	kfree(data);
1416 exit:
1417 	return err;
1418 }
1419 
1420 static int lm90_remove(struct i2c_client *client)
1421 {
1422 	struct lm90_data *data = i2c_get_clientdata(client);
1423 
1424 	hwmon_device_unregister(data->hwmon_dev);
1425 	lm90_remove_files(client, data);
1426 
1427 	/* Restore initial configuration */
1428 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
1429 				  data->convrate_orig);
1430 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
1431 				  data->config_orig);
1432 
1433 	kfree(data);
1434 	return 0;
1435 }
1436 
1437 static void lm90_alert(struct i2c_client *client, unsigned int flag)
1438 {
1439 	struct lm90_data *data = i2c_get_clientdata(client);
1440 	u8 config, alarms, alarms2 = 0;
1441 
1442 	lm90_read_reg(client, LM90_REG_R_STATUS, &alarms);
1443 
1444 	if (data->kind == max6696)
1445 		lm90_read_reg(client, MAX6696_REG_R_STATUS2, &alarms2);
1446 
1447 	if ((alarms & 0x7f) == 0 && (alarms2 & 0xfe) == 0) {
1448 		dev_info(&client->dev, "Everything OK\n");
1449 	} else {
1450 		if (alarms & 0x61)
1451 			dev_warn(&client->dev,
1452 				 "temp%d out of range, please check!\n", 1);
1453 		if (alarms & 0x1a)
1454 			dev_warn(&client->dev,
1455 				 "temp%d out of range, please check!\n", 2);
1456 		if (alarms & 0x04)
1457 			dev_warn(&client->dev,
1458 				 "temp%d diode open, please check!\n", 2);
1459 
1460 		if (alarms2 & 0x18)
1461 			dev_warn(&client->dev,
1462 				 "temp%d out of range, please check!\n", 3);
1463 
1464 		/* Disable ALERT# output, because these chips don't implement
1465 		  SMBus alert correctly; they should only hold the alert line
1466 		  low briefly. */
1467 		if ((data->flags & LM90_HAVE_BROKEN_ALERT)
1468 		 && (alarms & data->alert_alarms)) {
1469 			dev_dbg(&client->dev, "Disabling ALERT#\n");
1470 			lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
1471 			i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
1472 						  config | 0x80);
1473 		}
1474 	}
1475 }
1476 
1477 static struct i2c_driver lm90_driver = {
1478 	.class		= I2C_CLASS_HWMON,
1479 	.driver = {
1480 		.name	= "lm90",
1481 	},
1482 	.probe		= lm90_probe,
1483 	.remove		= lm90_remove,
1484 	.alert		= lm90_alert,
1485 	.id_table	= lm90_id,
1486 	.detect		= lm90_detect,
1487 	.address_list	= normal_i2c,
1488 };
1489 
1490 static int __init sensors_lm90_init(void)
1491 {
1492 	return i2c_add_driver(&lm90_driver);
1493 }
1494 
1495 static void __exit sensors_lm90_exit(void)
1496 {
1497 	i2c_del_driver(&lm90_driver);
1498 }
1499 
1500 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
1501 MODULE_DESCRIPTION("LM90/ADM1032 driver");
1502 MODULE_LICENSE("GPL");
1503 
1504 module_init(sensors_lm90_init);
1505 module_exit(sensors_lm90_exit);
1506