xref: /openbmc/linux/drivers/hwmon/lm90.c (revision 64c70b1c)
1 /*
2  * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
3  *          monitoring
4  * Copyright (C) 2003-2006  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. Complete datasheet can be
10  * obtained from National's website at:
11  *   http://www.national.com/pf/LM/LM90.html
12  *
13  * This driver also supports the LM89 and LM99, two other sensor chips
14  * made by National Semiconductor. Both have an increased remote
15  * temperature measurement accuracy (1 degree), and the LM99
16  * additionally shifts remote temperatures (measured and limits) by 16
17  * degrees, which allows for higher temperatures measurement. The
18  * driver doesn't handle it since it can be done easily in user-space.
19  * Complete datasheets can be obtained from National's website at:
20  *   http://www.national.com/pf/LM/LM89.html
21  *   http://www.national.com/pf/LM/LM99.html
22  * Note that there is no way to differentiate between both chips.
23  *
24  * This driver also supports the LM86, another sensor chip made by
25  * National Semiconductor. It is exactly similar to the LM90 except it
26  * has a higher accuracy.
27  * Complete datasheet can be obtained from National's website at:
28  *   http://www.national.com/pf/LM/LM86.html
29  *
30  * This driver also supports the ADM1032, a sensor chip made by Analog
31  * Devices. That chip is similar to the LM90, with a few differences
32  * that are not handled by this driver. Complete datasheet can be
33  * obtained from Analog's website at:
34  *   http://www.analog.com/en/prod/0,2877,ADM1032,00.html
35  * Among others, it has a higher accuracy than the LM90, much like the
36  * LM86 does.
37  *
38  * This driver also supports the MAX6657, MAX6658 and MAX6659 sensor
39  * chips made by Maxim. These chips are similar to the LM86. Complete
40  * datasheet can be obtained at Maxim's website at:
41  *   http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2578
42  * Note that there is no easy way to differentiate between the three
43  * variants. The extra address and features of the MAX6659 are not
44  * supported by this driver.
45  *
46  * This driver also supports the ADT7461 chip from Analog Devices but
47  * only in its "compatability mode". If an ADT7461 chip is found but
48  * is configured in non-compatible mode (where its temperature
49  * register values are decoded differently) it is ignored by this
50  * driver. Complete datasheet can be obtained from Analog's website
51  * at:
52  *   http://www.analog.com/en/prod/0,2877,ADT7461,00.html
53  *
54  * Since the LM90 was the first chipset supported by this driver, most
55  * comments will refer to this chipset, but are actually general and
56  * concern all supported chipsets, unless mentioned otherwise.
57  *
58  * This program is free software; you can redistribute it and/or modify
59  * it under the terms of the GNU General Public License as published by
60  * the Free Software Foundation; either version 2 of the License, or
61  * (at your option) any later version.
62  *
63  * This program is distributed in the hope that it will be useful,
64  * but WITHOUT ANY WARRANTY; without even the implied warranty of
65  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
66  * GNU General Public License for more details.
67  *
68  * You should have received a copy of the GNU General Public License
69  * along with this program; if not, write to the Free Software
70  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
71  */
72 
73 #include <linux/module.h>
74 #include <linux/init.h>
75 #include <linux/slab.h>
76 #include <linux/jiffies.h>
77 #include <linux/i2c.h>
78 #include <linux/hwmon-sysfs.h>
79 #include <linux/hwmon.h>
80 #include <linux/err.h>
81 #include <linux/mutex.h>
82 #include <linux/sysfs.h>
83 
84 /*
85  * Addresses to scan
86  * Address is fully defined internally and cannot be changed except for
87  * MAX6659.
88  * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, MAX6657 and MAX6658
89  * have address 0x4c.
90  * ADM1032-2, ADT7461-2, LM89-1, and LM99-1 have address 0x4d.
91  * MAX6659 can have address 0x4c, 0x4d or 0x4e (unsupported).
92  */
93 
94 static unsigned short normal_i2c[] = { 0x4c, 0x4d, I2C_CLIENT_END };
95 
96 /*
97  * Insmod parameters
98  */
99 
100 I2C_CLIENT_INSMOD_6(lm90, adm1032, lm99, lm86, max6657, adt7461);
101 
102 /*
103  * The LM90 registers
104  */
105 
106 #define LM90_REG_R_MAN_ID		0xFE
107 #define LM90_REG_R_CHIP_ID		0xFF
108 #define LM90_REG_R_CONFIG1		0x03
109 #define LM90_REG_W_CONFIG1		0x09
110 #define LM90_REG_R_CONFIG2		0xBF
111 #define LM90_REG_W_CONFIG2		0xBF
112 #define LM90_REG_R_CONVRATE		0x04
113 #define LM90_REG_W_CONVRATE		0x0A
114 #define LM90_REG_R_STATUS		0x02
115 #define LM90_REG_R_LOCAL_TEMP		0x00
116 #define LM90_REG_R_LOCAL_HIGH		0x05
117 #define LM90_REG_W_LOCAL_HIGH		0x0B
118 #define LM90_REG_R_LOCAL_LOW		0x06
119 #define LM90_REG_W_LOCAL_LOW		0x0C
120 #define LM90_REG_R_LOCAL_CRIT		0x20
121 #define LM90_REG_W_LOCAL_CRIT		0x20
122 #define LM90_REG_R_REMOTE_TEMPH		0x01
123 #define LM90_REG_R_REMOTE_TEMPL		0x10
124 #define LM90_REG_R_REMOTE_OFFSH		0x11
125 #define LM90_REG_W_REMOTE_OFFSH		0x11
126 #define LM90_REG_R_REMOTE_OFFSL		0x12
127 #define LM90_REG_W_REMOTE_OFFSL		0x12
128 #define LM90_REG_R_REMOTE_HIGHH		0x07
129 #define LM90_REG_W_REMOTE_HIGHH		0x0D
130 #define LM90_REG_R_REMOTE_HIGHL		0x13
131 #define LM90_REG_W_REMOTE_HIGHL		0x13
132 #define LM90_REG_R_REMOTE_LOWH		0x08
133 #define LM90_REG_W_REMOTE_LOWH		0x0E
134 #define LM90_REG_R_REMOTE_LOWL		0x14
135 #define LM90_REG_W_REMOTE_LOWL		0x14
136 #define LM90_REG_R_REMOTE_CRIT		0x19
137 #define LM90_REG_W_REMOTE_CRIT		0x19
138 #define LM90_REG_R_TCRIT_HYST		0x21
139 #define LM90_REG_W_TCRIT_HYST		0x21
140 
141 /*
142  * Conversions and various macros
143  * For local temperatures and limits, critical limits and the hysteresis
144  * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
145  * For remote temperatures and limits, it uses signed 11-bit values with
146  * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.
147  */
148 
149 #define TEMP1_FROM_REG(val)	((val) * 1000)
150 #define TEMP1_TO_REG(val)	((val) <= -128000 ? -128 : \
151 				 (val) >= 127000 ? 127 : \
152 				 (val) < 0 ? ((val) - 500) / 1000 : \
153 				 ((val) + 500) / 1000)
154 #define TEMP2_FROM_REG(val)	((val) / 32 * 125)
155 #define TEMP2_TO_REG(val)	((val) <= -128000 ? 0x8000 : \
156 				 (val) >= 127875 ? 0x7FE0 : \
157 				 (val) < 0 ? ((val) - 62) / 125 * 32 : \
158 				 ((val) + 62) / 125 * 32)
159 #define HYST_TO_REG(val)	((val) <= 0 ? 0 : (val) >= 30500 ? 31 : \
160 				 ((val) + 500) / 1000)
161 
162 /*
163  * ADT7461 is almost identical to LM90 except that attempts to write
164  * values that are outside the range 0 < temp < 127 are treated as
165  * the boundary value.
166  */
167 
168 #define TEMP1_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
169 				 (val) >= 127000 ? 127 : \
170 				 ((val) + 500) / 1000)
171 #define TEMP2_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
172 				 (val) >= 127750 ? 0x7FC0 : \
173 				 ((val) + 125) / 250 * 64)
174 
175 /*
176  * Functions declaration
177  */
178 
179 static int lm90_attach_adapter(struct i2c_adapter *adapter);
180 static int lm90_detect(struct i2c_adapter *adapter, int address,
181 	int kind);
182 static void lm90_init_client(struct i2c_client *client);
183 static int lm90_detach_client(struct i2c_client *client);
184 static struct lm90_data *lm90_update_device(struct device *dev);
185 
186 /*
187  * Driver data (common to all clients)
188  */
189 
190 static struct i2c_driver lm90_driver = {
191 	.driver = {
192 		.name	= "lm90",
193 	},
194 	.id		= I2C_DRIVERID_LM90,
195 	.attach_adapter	= lm90_attach_adapter,
196 	.detach_client	= lm90_detach_client,
197 };
198 
199 /*
200  * Client data (each client gets its own)
201  */
202 
203 struct lm90_data {
204 	struct i2c_client client;
205 	struct class_device *class_dev;
206 	struct mutex update_lock;
207 	char valid; /* zero until following fields are valid */
208 	unsigned long last_updated; /* in jiffies */
209 	int kind;
210 
211 	/* registers values */
212 	s8 temp8[5];	/* 0: local input
213 			   1: local low limit
214 			   2: local high limit
215 			   3: local critical limit
216 			   4: remote critical limit */
217 	s16 temp11[3];	/* 0: remote input
218 			   1: remote low limit
219 			   2: remote high limit */
220 	u8 temp_hyst;
221 	u8 alarms; /* bitvector */
222 };
223 
224 /*
225  * Sysfs stuff
226  */
227 
228 static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
229 			  char *buf)
230 {
231 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
232 	struct lm90_data *data = lm90_update_device(dev);
233 	return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index]));
234 }
235 
236 static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
237 			 const char *buf, size_t count)
238 {
239 	static const u8 reg[4] = {
240 		LM90_REG_W_LOCAL_LOW,
241 		LM90_REG_W_LOCAL_HIGH,
242 		LM90_REG_W_LOCAL_CRIT,
243 		LM90_REG_W_REMOTE_CRIT,
244 	};
245 
246 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
247 	struct i2c_client *client = to_i2c_client(dev);
248 	struct lm90_data *data = i2c_get_clientdata(client);
249 	long val = simple_strtol(buf, NULL, 10);
250 	int nr = attr->index;
251 
252 	mutex_lock(&data->update_lock);
253 	if (data->kind == adt7461)
254 		data->temp8[nr] = TEMP1_TO_REG_ADT7461(val);
255 	else
256 		data->temp8[nr] = TEMP1_TO_REG(val);
257 	i2c_smbus_write_byte_data(client, reg[nr - 1], data->temp8[nr]);
258 	mutex_unlock(&data->update_lock);
259 	return count;
260 }
261 
262 static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
263 			   char *buf)
264 {
265 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
266 	struct lm90_data *data = lm90_update_device(dev);
267 	return sprintf(buf, "%d\n", TEMP2_FROM_REG(data->temp11[attr->index]));
268 }
269 
270 static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
271 			  const char *buf, size_t count)
272 {
273 	static const u8 reg[4] = {
274 		LM90_REG_W_REMOTE_LOWH,
275 		LM90_REG_W_REMOTE_LOWL,
276 		LM90_REG_W_REMOTE_HIGHH,
277 		LM90_REG_W_REMOTE_HIGHL,
278 	};
279 
280 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
281 	struct i2c_client *client = to_i2c_client(dev);
282 	struct lm90_data *data = i2c_get_clientdata(client);
283 	long val = simple_strtol(buf, NULL, 10);
284 	int nr = attr->index;
285 
286 	mutex_lock(&data->update_lock);
287 	if (data->kind == adt7461)
288 		data->temp11[nr] = TEMP2_TO_REG_ADT7461(val);
289 	else
290 		data->temp11[nr] = TEMP2_TO_REG(val);
291 	i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
292 				  data->temp11[nr] >> 8);
293 	i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
294 				  data->temp11[nr] & 0xff);
295 	mutex_unlock(&data->update_lock);
296 	return count;
297 }
298 
299 static ssize_t show_temphyst(struct device *dev, struct device_attribute *devattr,
300 			     char *buf)
301 {
302 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
303 	struct lm90_data *data = lm90_update_device(dev);
304 	return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index])
305 		       - TEMP1_FROM_REG(data->temp_hyst));
306 }
307 
308 static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
309 			    const char *buf, size_t count)
310 {
311 	struct i2c_client *client = to_i2c_client(dev);
312 	struct lm90_data *data = i2c_get_clientdata(client);
313 	long val = simple_strtol(buf, NULL, 10);
314 	long hyst;
315 
316 	mutex_lock(&data->update_lock);
317 	hyst = TEMP1_FROM_REG(data->temp8[3]) - val;
318 	i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
319 				  HYST_TO_REG(hyst));
320 	mutex_unlock(&data->update_lock);
321 	return count;
322 }
323 
324 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
325 			   char *buf)
326 {
327 	struct lm90_data *data = lm90_update_device(dev);
328 	return sprintf(buf, "%d\n", data->alarms);
329 }
330 
331 static ssize_t show_alarm(struct device *dev, struct device_attribute
332 			  *devattr, char *buf)
333 {
334 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
335 	struct lm90_data *data = lm90_update_device(dev);
336 	int bitnr = attr->index;
337 
338 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
339 }
340 
341 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp8, NULL, 0);
342 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp11, NULL, 0);
343 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
344 	set_temp8, 1);
345 static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
346 	set_temp11, 1);
347 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
348 	set_temp8, 2);
349 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
350 	set_temp11, 2);
351 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
352 	set_temp8, 3);
353 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
354 	set_temp8, 4);
355 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
356 	set_temphyst, 3);
357 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 4);
358 
359 /* Individual alarm files */
360 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
361 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
362 static SENSOR_DEVICE_ATTR(temp2_input_fault, S_IRUGO, show_alarm, NULL, 2);
363 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
364 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
365 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 5);
366 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
367 /* Raw alarm file for compatibility */
368 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
369 
370 static struct attribute *lm90_attributes[] = {
371 	&sensor_dev_attr_temp1_input.dev_attr.attr,
372 	&sensor_dev_attr_temp2_input.dev_attr.attr,
373 	&sensor_dev_attr_temp1_min.dev_attr.attr,
374 	&sensor_dev_attr_temp2_min.dev_attr.attr,
375 	&sensor_dev_attr_temp1_max.dev_attr.attr,
376 	&sensor_dev_attr_temp2_max.dev_attr.attr,
377 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
378 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
379 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
380 	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
381 
382 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
383 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
384 	&sensor_dev_attr_temp2_input_fault.dev_attr.attr,
385 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
386 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
387 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
388 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
389 	&dev_attr_alarms.attr,
390 	NULL
391 };
392 
393 static const struct attribute_group lm90_group = {
394 	.attrs = lm90_attributes,
395 };
396 
397 /* pec used for ADM1032 only */
398 static ssize_t show_pec(struct device *dev, struct device_attribute *dummy,
399 			char *buf)
400 {
401 	struct i2c_client *client = to_i2c_client(dev);
402 	return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
403 }
404 
405 static ssize_t set_pec(struct device *dev, struct device_attribute *dummy,
406 		       const char *buf, size_t count)
407 {
408 	struct i2c_client *client = to_i2c_client(dev);
409 	long val = simple_strtol(buf, NULL, 10);
410 
411 	switch (val) {
412 	case 0:
413 		client->flags &= ~I2C_CLIENT_PEC;
414 		break;
415 	case 1:
416 		client->flags |= I2C_CLIENT_PEC;
417 		break;
418 	default:
419 		return -EINVAL;
420 	}
421 
422 	return count;
423 }
424 
425 static DEVICE_ATTR(pec, S_IWUSR | S_IRUGO, show_pec, set_pec);
426 
427 /*
428  * Real code
429  */
430 
431 /* The ADM1032 supports PEC but not on write byte transactions, so we need
432    to explicitely ask for a transaction without PEC. */
433 static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value)
434 {
435 	return i2c_smbus_xfer(client->adapter, client->addr,
436 			      client->flags & ~I2C_CLIENT_PEC,
437 			      I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
438 }
439 
440 /* It is assumed that client->update_lock is held (unless we are in
441    detection or initialization steps). This matters when PEC is enabled,
442    because we don't want the address pointer to change between the write
443    byte and the read byte transactions. */
444 static int lm90_read_reg(struct i2c_client* client, u8 reg, u8 *value)
445 {
446 	int err;
447 
448  	if (client->flags & I2C_CLIENT_PEC) {
449  		err = adm1032_write_byte(client, reg);
450  		if (err >= 0)
451  			err = i2c_smbus_read_byte(client);
452  	} else
453  		err = i2c_smbus_read_byte_data(client, reg);
454 
455 	if (err < 0) {
456 		dev_warn(&client->dev, "Register %#02x read failed (%d)\n",
457 			 reg, err);
458 		return err;
459 	}
460 	*value = err;
461 
462 	return 0;
463 }
464 
465 static int lm90_attach_adapter(struct i2c_adapter *adapter)
466 {
467 	if (!(adapter->class & I2C_CLASS_HWMON))
468 		return 0;
469 	return i2c_probe(adapter, &addr_data, lm90_detect);
470 }
471 
472 /*
473  * The following function does more than just detection. If detection
474  * succeeds, it also registers the new chip.
475  */
476 static int lm90_detect(struct i2c_adapter *adapter, int address, int kind)
477 {
478 	struct i2c_client *new_client;
479 	struct lm90_data *data;
480 	int err = 0;
481 	const char *name = "";
482 
483 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
484 		goto exit;
485 
486 	if (!(data = kzalloc(sizeof(struct lm90_data), GFP_KERNEL))) {
487 		err = -ENOMEM;
488 		goto exit;
489 	}
490 
491 	/* The common I2C client data is placed right before the
492 	   LM90-specific data. */
493 	new_client = &data->client;
494 	i2c_set_clientdata(new_client, data);
495 	new_client->addr = address;
496 	new_client->adapter = adapter;
497 	new_client->driver = &lm90_driver;
498 	new_client->flags = 0;
499 
500 	/*
501 	 * Now we do the remaining detection. A negative kind means that
502 	 * the driver was loaded with no force parameter (default), so we
503 	 * must both detect and identify the chip. A zero kind means that
504 	 * the driver was loaded with the force parameter, the detection
505 	 * step shall be skipped. A positive kind means that the driver
506 	 * was loaded with the force parameter and a given kind of chip is
507 	 * requested, so both the detection and the identification steps
508 	 * are skipped.
509 	 */
510 
511 	/* Default to an LM90 if forced */
512 	if (kind == 0)
513 		kind = lm90;
514 
515 	if (kind < 0) { /* detection and identification */
516 		u8 man_id, chip_id, reg_config1, reg_convrate;
517 
518 		if (lm90_read_reg(new_client, LM90_REG_R_MAN_ID,
519 				  &man_id) < 0
520 		 || lm90_read_reg(new_client, LM90_REG_R_CHIP_ID,
521 		 		  &chip_id) < 0
522 		 || lm90_read_reg(new_client, LM90_REG_R_CONFIG1,
523 		 		  &reg_config1) < 0
524 		 || lm90_read_reg(new_client, LM90_REG_R_CONVRATE,
525 		 		  &reg_convrate) < 0)
526 			goto exit_free;
527 
528 		if (man_id == 0x01) { /* National Semiconductor */
529 			u8 reg_config2;
530 
531 			if (lm90_read_reg(new_client, LM90_REG_R_CONFIG2,
532 					  &reg_config2) < 0)
533 				goto exit_free;
534 
535 			if ((reg_config1 & 0x2A) == 0x00
536 			 && (reg_config2 & 0xF8) == 0x00
537 			 && reg_convrate <= 0x09) {
538 				if (address == 0x4C
539 				 && (chip_id & 0xF0) == 0x20) { /* LM90 */
540 					kind = lm90;
541 				} else
542 				if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
543 					kind = lm99;
544 				} else
545 				if (address == 0x4C
546 				 && (chip_id & 0xF0) == 0x10) { /* LM86 */
547 					kind = lm86;
548 				}
549 			}
550 		} else
551 		if (man_id == 0x41) { /* Analog Devices */
552 			if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
553 			 && (reg_config1 & 0x3F) == 0x00
554 			 && reg_convrate <= 0x0A) {
555 				kind = adm1032;
556 			} else
557 			if (chip_id == 0x51 /* ADT7461 */
558 			 && (reg_config1 & 0x1F) == 0x00 /* check compat mode */
559 			 && reg_convrate <= 0x0A) {
560 				kind = adt7461;
561 			}
562 		} else
563 		if (man_id == 0x4D) { /* Maxim */
564 			/*
565 			 * The Maxim variants do NOT have a chip_id register.
566 			 * Reading from that address will return the last read
567 			 * value, which in our case is those of the man_id
568 			 * register. Likewise, the config1 register seems to
569 			 * lack a low nibble, so the value will be those of the
570 			 * previous read, so in our case those of the man_id
571 			 * register.
572 			 */
573 			if (chip_id == man_id
574 			 && (reg_config1 & 0x1F) == (man_id & 0x0F)
575 			 && reg_convrate <= 0x09) {
576 			 	kind = max6657;
577 			}
578 		}
579 
580 		if (kind <= 0) { /* identification failed */
581 			dev_info(&adapter->dev,
582 			    "Unsupported chip (man_id=0x%02X, "
583 			    "chip_id=0x%02X).\n", man_id, chip_id);
584 			goto exit_free;
585 		}
586 	}
587 
588 	if (kind == lm90) {
589 		name = "lm90";
590 	} else if (kind == adm1032) {
591 		name = "adm1032";
592 		/* The ADM1032 supports PEC, but only if combined
593 		   transactions are not used. */
594 		if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
595 			new_client->flags |= I2C_CLIENT_PEC;
596 	} else if (kind == lm99) {
597 		name = "lm99";
598 	} else if (kind == lm86) {
599 		name = "lm86";
600 	} else if (kind == max6657) {
601 		name = "max6657";
602 	} else if (kind == adt7461) {
603 		name = "adt7461";
604 	}
605 
606 	/* We can fill in the remaining client fields */
607 	strlcpy(new_client->name, name, I2C_NAME_SIZE);
608 	data->valid = 0;
609 	data->kind = kind;
610 	mutex_init(&data->update_lock);
611 
612 	/* Tell the I2C layer a new client has arrived */
613 	if ((err = i2c_attach_client(new_client)))
614 		goto exit_free;
615 
616 	/* Initialize the LM90 chip */
617 	lm90_init_client(new_client);
618 
619 	/* Register sysfs hooks */
620 	if ((err = sysfs_create_group(&new_client->dev.kobj, &lm90_group)))
621 		goto exit_detach;
622 	if (new_client->flags & I2C_CLIENT_PEC) {
623 		if ((err = device_create_file(&new_client->dev,
624 					      &dev_attr_pec)))
625 			goto exit_remove_files;
626 	}
627 
628 	data->class_dev = hwmon_device_register(&new_client->dev);
629 	if (IS_ERR(data->class_dev)) {
630 		err = PTR_ERR(data->class_dev);
631 		goto exit_remove_files;
632 	}
633 
634 	return 0;
635 
636 exit_remove_files:
637 	sysfs_remove_group(&new_client->dev.kobj, &lm90_group);
638 	device_remove_file(&new_client->dev, &dev_attr_pec);
639 exit_detach:
640 	i2c_detach_client(new_client);
641 exit_free:
642 	kfree(data);
643 exit:
644 	return err;
645 }
646 
647 static void lm90_init_client(struct i2c_client *client)
648 {
649 	u8 config;
650 
651 	/*
652 	 * Start the conversions.
653 	 */
654 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
655 				  5); /* 2 Hz */
656 	if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) {
657 		dev_warn(&client->dev, "Initialization failed!\n");
658 		return;
659 	}
660 	if (config & 0x40)
661 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
662 					  config & 0xBF); /* run */
663 }
664 
665 static int lm90_detach_client(struct i2c_client *client)
666 {
667 	struct lm90_data *data = i2c_get_clientdata(client);
668 	int err;
669 
670 	hwmon_device_unregister(data->class_dev);
671 	sysfs_remove_group(&client->dev.kobj, &lm90_group);
672 	device_remove_file(&client->dev, &dev_attr_pec);
673 
674 	if ((err = i2c_detach_client(client)))
675 		return err;
676 
677 	kfree(data);
678 	return 0;
679 }
680 
681 static struct lm90_data *lm90_update_device(struct device *dev)
682 {
683 	struct i2c_client *client = to_i2c_client(dev);
684 	struct lm90_data *data = i2c_get_clientdata(client);
685 
686 	mutex_lock(&data->update_lock);
687 
688 	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
689 		u8 oldh, newh, l;
690 
691 		dev_dbg(&client->dev, "Updating lm90 data.\n");
692 		lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP, &data->temp8[0]);
693 		lm90_read_reg(client, LM90_REG_R_LOCAL_LOW, &data->temp8[1]);
694 		lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH, &data->temp8[2]);
695 		lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT, &data->temp8[3]);
696 		lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[4]);
697 		lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
698 
699 		/*
700 		 * There is a trick here. We have to read two registers to
701 		 * have the remote sensor temperature, but we have to beware
702 		 * a conversion could occur inbetween the readings. The
703 		 * datasheet says we should either use the one-shot
704 		 * conversion register, which we don't want to do (disables
705 		 * hardware monitoring) or monitor the busy bit, which is
706 		 * impossible (we can't read the values and monitor that bit
707 		 * at the exact same time). So the solution used here is to
708 		 * read the high byte once, then the low byte, then the high
709 		 * byte again. If the new high byte matches the old one,
710 		 * then we have a valid reading. Else we have to read the low
711 		 * byte again, and now we believe we have a correct reading.
712 		 */
713 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPH, &oldh) == 0
714 		 && lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPL, &l) == 0
715 		 && lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPH, &newh) == 0
716 		 && (newh == oldh
717 		  || lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPL, &l) == 0))
718 			data->temp11[0] = (newh << 8) | l;
719 
720 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &newh) == 0
721 		 && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL, &l) == 0)
722 			data->temp11[1] = (newh << 8) | l;
723 		if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &newh) == 0
724 		 && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL, &l) == 0)
725 			data->temp11[2] = (newh << 8) | l;
726 		lm90_read_reg(client, LM90_REG_R_STATUS, &data->alarms);
727 
728 		data->last_updated = jiffies;
729 		data->valid = 1;
730 	}
731 
732 	mutex_unlock(&data->update_lock);
733 
734 	return data;
735 }
736 
737 static int __init sensors_lm90_init(void)
738 {
739 	return i2c_add_driver(&lm90_driver);
740 }
741 
742 static void __exit sensors_lm90_exit(void)
743 {
744 	i2c_del_driver(&lm90_driver);
745 }
746 
747 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
748 MODULE_DESCRIPTION("LM90/ADM1032 driver");
749 MODULE_LICENSE("GPL");
750 
751 module_init(sensors_lm90_init);
752 module_exit(sensors_lm90_exit);
753