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1/*
2 * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
3 * monitoring
4 * Copyright (C) 2003-2005 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://products.analog.com/products/info.asp?product=ADM1032
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://products.analog.com/products/info.asp?product=ADT7461
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/i2c-sensor.h>
79#include <linux/hwmon-sysfs.h>
80
81/*
82 * Addresses to scan
83 * Address is fully defined internally and cannot be changed except for
84 * MAX6659.
85 * LM86, LM89, LM90, LM99, ADM1032, MAX6657 and MAX6658 have address 0x4c.
86 * LM89-1, and LM99-1 have address 0x4d.
87 * MAX6659 can have address 0x4c, 0x4d or 0x4e (unsupported).
88 * ADT7461 always has address 0x4c.
89 */
90
91static unsigned short normal_i2c[] = { 0x4c, 0x4d, I2C_CLIENT_END };
92static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
93
94/*
95 * Insmod parameters
96 */
97
98SENSORS_INSMOD_6(lm90, adm1032, lm99, lm86, max6657, adt7461);
99
100/*
101 * The LM90 registers
102 */
103
104#define LM90_REG_R_MAN_ID 0xFE
105#define LM90_REG_R_CHIP_ID 0xFF
106#define LM90_REG_R_CONFIG1 0x03
107#define LM90_REG_W_CONFIG1 0x09
108#define LM90_REG_R_CONFIG2 0xBF
109#define LM90_REG_W_CONFIG2 0xBF
110#define LM90_REG_R_CONVRATE 0x04
111#define LM90_REG_W_CONVRATE 0x0A
112#define LM90_REG_R_STATUS 0x02
113#define LM90_REG_R_LOCAL_TEMP 0x00
114#define LM90_REG_R_LOCAL_HIGH 0x05
115#define LM90_REG_W_LOCAL_HIGH 0x0B
116#define LM90_REG_R_LOCAL_LOW 0x06
117#define LM90_REG_W_LOCAL_LOW 0x0C
118#define LM90_REG_R_LOCAL_CRIT 0x20
119#define LM90_REG_W_LOCAL_CRIT 0x20
120#define LM90_REG_R_REMOTE_TEMPH 0x01
121#define LM90_REG_R_REMOTE_TEMPL 0x10
122#define LM90_REG_R_REMOTE_OFFSH 0x11
123#define LM90_REG_W_REMOTE_OFFSH 0x11
124#define LM90_REG_R_REMOTE_OFFSL 0x12
125#define LM90_REG_W_REMOTE_OFFSL 0x12
126#define LM90_REG_R_REMOTE_HIGHH 0x07
127#define LM90_REG_W_REMOTE_HIGHH 0x0D
128#define LM90_REG_R_REMOTE_HIGHL 0x13
129#define LM90_REG_W_REMOTE_HIGHL 0x13
130#define LM90_REG_R_REMOTE_LOWH 0x08
131#define LM90_REG_W_REMOTE_LOWH 0x0E
132#define LM90_REG_R_REMOTE_LOWL 0x14
133#define LM90_REG_W_REMOTE_LOWL 0x14
134#define LM90_REG_R_REMOTE_CRIT 0x19
135#define LM90_REG_W_REMOTE_CRIT 0x19
136#define LM90_REG_R_TCRIT_HYST 0x21
137#define LM90_REG_W_TCRIT_HYST 0x21
138
139/*
140 * Conversions and various macros
141 * For local temperatures and limits, critical limits and the hysteresis
142 * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
143 * For remote temperatures and limits, it uses signed 11-bit values with
144 * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.
145 */
146
147#define TEMP1_FROM_REG(val) ((val) * 1000)
148#define TEMP1_TO_REG(val) ((val) <= -128000 ? -128 : \
149 (val) >= 127000 ? 127 : \
150 (val) < 0 ? ((val) - 500) / 1000 : \
151 ((val) + 500) / 1000)
152#define TEMP2_FROM_REG(val) ((val) / 32 * 125)
153#define TEMP2_TO_REG(val) ((val) <= -128000 ? 0x8000 : \
154 (val) >= 127875 ? 0x7FE0 : \
155 (val) < 0 ? ((val) - 62) / 125 * 32 : \
156 ((val) + 62) / 125 * 32)
157#define HYST_TO_REG(val) ((val) <= 0 ? 0 : (val) >= 30500 ? 31 : \
158 ((val) + 500) / 1000)
159
160/*
161 * ADT7461 is almost identical to LM90 except that attempts to write
162 * values that are outside the range 0 < temp < 127 are treated as
163 * the boundary value.
164 */
165
166#define TEMP1_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
167 (val) >= 127000 ? 127 : \
168 ((val) + 500) / 1000)
169#define TEMP2_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
170 (val) >= 127750 ? 0x7FC0 : \
171 ((val) + 125) / 250 * 64)
172
173/*
174 * Functions declaration
175 */
176
177static int lm90_attach_adapter(struct i2c_adapter *adapter);
178static int lm90_detect(struct i2c_adapter *adapter, int address,
179 int kind);
180static void lm90_init_client(struct i2c_client *client);
181static int lm90_detach_client(struct i2c_client *client);
182static struct lm90_data *lm90_update_device(struct device *dev);
183
184/*
185 * Driver data (common to all clients)
186 */
187
188static struct i2c_driver lm90_driver = {
189 .owner = THIS_MODULE,
190 .name = "lm90",
191 .id = I2C_DRIVERID_LM90,
192 .flags = I2C_DF_NOTIFY,
193 .attach_adapter = lm90_attach_adapter,
194 .detach_client = lm90_detach_client,
195};
196
197/*
198 * Client data (each client gets its own)
199 */
200
201struct lm90_data {
202 struct i2c_client client;
203 struct semaphore update_lock;
204 char valid; /* zero until following fields are valid */
205 unsigned long last_updated; /* in jiffies */
206 int kind;
207
208 /* registers values */
209 s8 temp8[5]; /* 0: local input
210 1: local low limit
211 2: local high limit
212 3: local critical limit
213 4: remote critical limit */
214 s16 temp11[3]; /* 0: remote input
215 1: remote low limit
216 2: remote high limit */
217 u8 temp_hyst;
218 u8 alarms; /* bitvector */
219};
220
221/*
222 * Sysfs stuff
223 */
224
225static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
226 char *buf)
227{
228 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
229 struct lm90_data *data = lm90_update_device(dev);
230 return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index]));
231}
232
233static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
234 const char *buf, size_t count)
235{
236 static const u8 reg[4] = {
237 LM90_REG_W_LOCAL_LOW,
238 LM90_REG_W_LOCAL_HIGH,
239 LM90_REG_W_LOCAL_CRIT,
240 LM90_REG_W_REMOTE_CRIT,
241 };
242
243 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
244 struct i2c_client *client = to_i2c_client(dev);
245 struct lm90_data *data = i2c_get_clientdata(client);
246 long val = simple_strtol(buf, NULL, 10);
247 int nr = attr->index;
248
249 down(&data->update_lock);
250 if (data->kind == adt7461)
251 data->temp8[nr] = TEMP1_TO_REG_ADT7461(val);
252 else
253 data->temp8[nr] = TEMP1_TO_REG(val);
254 i2c_smbus_write_byte_data(client, reg[nr - 1], data->temp8[nr]);
255 up(&data->update_lock);
256 return count;
257}
258
259static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
260 char *buf)
261{
262 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
263 struct lm90_data *data = lm90_update_device(dev);
264 return sprintf(buf, "%d\n", TEMP2_FROM_REG(data->temp11[attr->index]));
265}
266
267static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
268 const char *buf, size_t count)
269{
270 static const u8 reg[4] = {
271 LM90_REG_W_REMOTE_LOWH,
272 LM90_REG_W_REMOTE_LOWL,
273 LM90_REG_W_REMOTE_HIGHH,
274 LM90_REG_W_REMOTE_HIGHL,
275 };
276
277 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
278 struct i2c_client *client = to_i2c_client(dev);
279 struct lm90_data *data = i2c_get_clientdata(client);
280 long val = simple_strtol(buf, NULL, 10);
281 int nr = attr->index;
282
283 down(&data->update_lock);
284 if (data->kind == adt7461)
285 data->temp11[nr] = TEMP2_TO_REG_ADT7461(val);
286 else
287 data->temp11[nr] = TEMP2_TO_REG(val);
288 i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
289 data->temp11[nr] >> 8);
290 i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
291 data->temp11[nr] & 0xff);
292 up(&data->update_lock);
293 return count;
294}
295
296static ssize_t show_temphyst(struct device *dev, struct device_attribute *devattr,
297 char *buf)
298{
299 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
300 struct lm90_data *data = lm90_update_device(dev);
301 return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index])
302 - TEMP1_FROM_REG(data->temp_hyst));
303}
304
305static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
306 const char *buf, size_t count)
307{
308 struct i2c_client *client = to_i2c_client(dev);
309 struct lm90_data *data = i2c_get_clientdata(client);
310 long val = simple_strtol(buf, NULL, 10);
311 long hyst;
312
313 down(&data->update_lock);
314 hyst = TEMP1_FROM_REG(data->temp8[3]) - val;
315 i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
316 HYST_TO_REG(hyst));
317 up(&data->update_lock);
318 return count;
319}
320
321static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
322 char *buf)
323{
324 struct lm90_data *data = lm90_update_device(dev);
325 return sprintf(buf, "%d\n", data->alarms);
326}
327
328static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp8, NULL, 0);
329static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp11, NULL, 0);
330static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
331 set_temp8, 1);
332static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
333 set_temp11, 1);
334static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
335 set_temp8, 2);
336static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
337 set_temp11, 2);
338static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
339 set_temp8, 3);
340static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
341 set_temp8, 4);
342static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
343 set_temphyst, 3);
344static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 4);
345static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
346
347/*
348 * Real code
349 */
350
351static int lm90_attach_adapter(struct i2c_adapter *adapter)
352{
353 if (!(adapter->class & I2C_CLASS_HWMON))
354 return 0;
355 return i2c_detect(adapter, &addr_data, lm90_detect);
356}
357
358/*
359 * The following function does more than just detection. If detection
360 * succeeds, it also registers the new chip.
361 */
362static int lm90_detect(struct i2c_adapter *adapter, int address, int kind)
363{
364 struct i2c_client *new_client;
365 struct lm90_data *data;
366 int err = 0;
367 const char *name = "";
368
369 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
370 goto exit;
371
372 if (!(data = kmalloc(sizeof(struct lm90_data), GFP_KERNEL))) {
373 err = -ENOMEM;
374 goto exit;
375 }
376 memset(data, 0, sizeof(struct lm90_data));
377
378 /* The common I2C client data is placed right before the
379 LM90-specific data. */
380 new_client = &data->client;
381 i2c_set_clientdata(new_client, data);
382 new_client->addr = address;
383 new_client->adapter = adapter;
384 new_client->driver = &lm90_driver;
385 new_client->flags = 0;
386
387 /*
388 * Now we do the remaining detection. A negative kind means that
389 * the driver was loaded with no force parameter (default), so we
390 * must both detect and identify the chip. A zero kind means that
391 * the driver was loaded with the force parameter, the detection
392 * step shall be skipped. A positive kind means that the driver
393 * was loaded with the force parameter and a given kind of chip is
394 * requested, so both the detection and the identification steps
395 * are skipped.
396 */
397
398 /* Default to an LM90 if forced */
399 if (kind == 0)
400 kind = lm90;
401
402 if (kind < 0) { /* detection and identification */
403 u8 man_id, chip_id, reg_config1, reg_convrate;
404
405 man_id = i2c_smbus_read_byte_data(new_client,
406 LM90_REG_R_MAN_ID);
407 chip_id = i2c_smbus_read_byte_data(new_client,
408 LM90_REG_R_CHIP_ID);
409 reg_config1 = i2c_smbus_read_byte_data(new_client,
410 LM90_REG_R_CONFIG1);
411 reg_convrate = i2c_smbus_read_byte_data(new_client,
412 LM90_REG_R_CONVRATE);
413
414 if (man_id == 0x01) { /* National Semiconductor */
415 u8 reg_config2;
416
417 reg_config2 = i2c_smbus_read_byte_data(new_client,
418 LM90_REG_R_CONFIG2);
419
420 if ((reg_config1 & 0x2A) == 0x00
421 && (reg_config2 & 0xF8) == 0x00
422 && reg_convrate <= 0x09) {
423 if (address == 0x4C
424 && (chip_id & 0xF0) == 0x20) { /* LM90 */
425 kind = lm90;
426 } else
427 if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
428 kind = lm99;
429 } else
430 if (address == 0x4C
431 && (chip_id & 0xF0) == 0x10) { /* LM86 */
432 kind = lm86;
433 }
434 }
435 } else
436 if (man_id == 0x41) { /* Analog Devices */
437 if (address == 0x4C
438 && (chip_id & 0xF0) == 0x40 /* ADM1032 */
439 && (reg_config1 & 0x3F) == 0x00
440 && reg_convrate <= 0x0A) {
441 kind = adm1032;
442 } else
443 if (address == 0x4c
444 && chip_id == 0x51 /* ADT7461 */
445 && (reg_config1 & 0x1F) == 0x00 /* check compat mode */
446 && reg_convrate <= 0x0A) {
447 kind = adt7461;
448 }
449 } else
450 if (man_id == 0x4D) { /* Maxim */
451 /*
452 * The Maxim variants do NOT have a chip_id register.
453 * Reading from that address will return the last read
454 * value, which in our case is those of the man_id
455 * register. Likewise, the config1 register seems to
456 * lack a low nibble, so the value will be those of the
457 * previous read, so in our case those of the man_id
458 * register.
459 */
460 if (chip_id == man_id
461 && (reg_config1 & 0x1F) == (man_id & 0x0F)
462 && reg_convrate <= 0x09) {
463 kind = max6657;
464 }
465 }
466
467 if (kind <= 0) { /* identification failed */
468 dev_info(&adapter->dev,
469 "Unsupported chip (man_id=0x%02X, "
470 "chip_id=0x%02X).\n", man_id, chip_id);
471 goto exit_free;
472 }
473 }
474
475 if (kind == lm90) {
476 name = "lm90";
477 } else if (kind == adm1032) {
478 name = "adm1032";
479 } else if (kind == lm99) {
480 name = "lm99";
481 } else if (kind == lm86) {
482 name = "lm86";
483 } else if (kind == max6657) {
484 name = "max6657";
485 } else if (kind == adt7461) {
486 name = "adt7461";
487 }
488
489 /* We can fill in the remaining client fields */
490 strlcpy(new_client->name, name, I2C_NAME_SIZE);
491 data->valid = 0;
492 data->kind = kind;
493 init_MUTEX(&data->update_lock);
494
495 /* Tell the I2C layer a new client has arrived */
496 if ((err = i2c_attach_client(new_client)))
497 goto exit_free;
498
499 /* Initialize the LM90 chip */
500 lm90_init_client(new_client);
501
502 /* Register sysfs hooks */
503 device_create_file(&new_client->dev,
504 &sensor_dev_attr_temp1_input.dev_attr);
505 device_create_file(&new_client->dev,
506 &sensor_dev_attr_temp2_input.dev_attr);
507 device_create_file(&new_client->dev,
508 &sensor_dev_attr_temp1_min.dev_attr);
509 device_create_file(&new_client->dev,
510 &sensor_dev_attr_temp2_min.dev_attr);
511 device_create_file(&new_client->dev,
512 &sensor_dev_attr_temp1_max.dev_attr);
513 device_create_file(&new_client->dev,
514 &sensor_dev_attr_temp2_max.dev_attr);
515 device_create_file(&new_client->dev,
516 &sensor_dev_attr_temp1_crit.dev_attr);
517 device_create_file(&new_client->dev,
518 &sensor_dev_attr_temp2_crit.dev_attr);
519 device_create_file(&new_client->dev,
520 &sensor_dev_attr_temp1_crit_hyst.dev_attr);
521 device_create_file(&new_client->dev,
522 &sensor_dev_attr_temp2_crit_hyst.dev_attr);
523 device_create_file(&new_client->dev, &dev_attr_alarms);
524
525 return 0;
526
527exit_free:
528 kfree(data);
529exit:
530 return err;
531}
532
533static void lm90_init_client(struct i2c_client *client)
534{
535 u8 config;
536
537 /*
538 * Start the conversions.
539 */
540 i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
541 5); /* 2 Hz */
542 config = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG1);
543 if (config & 0x40)
544 i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
545 config & 0xBF); /* run */
546}
547
548static int lm90_detach_client(struct i2c_client *client)
549{
550 int err;
551
552 if ((err = i2c_detach_client(client))) {
553 dev_err(&client->dev, "Client deregistration failed, "
554 "client not detached.\n");
555 return err;
556 }
557
558 kfree(i2c_get_clientdata(client));
559 return 0;
560}
561
562static struct lm90_data *lm90_update_device(struct device *dev)
563{
564 struct i2c_client *client = to_i2c_client(dev);
565 struct lm90_data *data = i2c_get_clientdata(client);
566
567 down(&data->update_lock);
568
569 if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
570 u8 oldh, newh;
571
572 dev_dbg(&client->dev, "Updating lm90 data.\n");
573 data->temp8[0] = i2c_smbus_read_byte_data(client,
574 LM90_REG_R_LOCAL_TEMP);
575 data->temp8[1] = i2c_smbus_read_byte_data(client,
576 LM90_REG_R_LOCAL_LOW);
577 data->temp8[2] = i2c_smbus_read_byte_data(client,
578 LM90_REG_R_LOCAL_HIGH);
579 data->temp8[3] = i2c_smbus_read_byte_data(client,
580 LM90_REG_R_LOCAL_CRIT);
581 data->temp8[4] = i2c_smbus_read_byte_data(client,
582 LM90_REG_R_REMOTE_CRIT);
583 data->temp_hyst = i2c_smbus_read_byte_data(client,
584 LM90_REG_R_TCRIT_HYST);
585
586 /*
587 * There is a trick here. We have to read two registers to
588 * have the remote sensor temperature, but we have to beware
589 * a conversion could occur inbetween the readings. The
590 * datasheet says we should either use the one-shot
591 * conversion register, which we don't want to do (disables
592 * hardware monitoring) or monitor the busy bit, which is
593 * impossible (we can't read the values and monitor that bit
594 * at the exact same time). So the solution used here is to
595 * read the high byte once, then the low byte, then the high
596 * byte again. If the new high byte matches the old one,
597 * then we have a valid reading. Else we have to read the low
598 * byte again, and now we believe we have a correct reading.
599 */
600 oldh = i2c_smbus_read_byte_data(client,
601 LM90_REG_R_REMOTE_TEMPH);
602 data->temp11[0] = i2c_smbus_read_byte_data(client,
603 LM90_REG_R_REMOTE_TEMPL);
604 newh = i2c_smbus_read_byte_data(client,
605 LM90_REG_R_REMOTE_TEMPH);
606 if (newh != oldh) {
607 data->temp11[0] = i2c_smbus_read_byte_data(client,
608 LM90_REG_R_REMOTE_TEMPL);
609#ifdef DEBUG
610 oldh = i2c_smbus_read_byte_data(client,
611 LM90_REG_R_REMOTE_TEMPH);
612 /* oldh is actually newer */
613 if (newh != oldh)
614 dev_warn(&client->dev, "Remote temperature may be "
615 "wrong.\n");
616#endif
617 }
618 data->temp11[0] |= (newh << 8);
619
620 data->temp11[1] = (i2c_smbus_read_byte_data(client,
621 LM90_REG_R_REMOTE_LOWH) << 8) +
622 i2c_smbus_read_byte_data(client,
623 LM90_REG_R_REMOTE_LOWL);
624 data->temp11[2] = (i2c_smbus_read_byte_data(client,
625 LM90_REG_R_REMOTE_HIGHH) << 8) +
626 i2c_smbus_read_byte_data(client,
627 LM90_REG_R_REMOTE_HIGHL);
628 data->alarms = i2c_smbus_read_byte_data(client,
629 LM90_REG_R_STATUS);
630
631 data->last_updated = jiffies;
632 data->valid = 1;
633 }
634
635 up(&data->update_lock);
636
637 return data;
638}
639
640static int __init sensors_lm90_init(void)
641{
642 return i2c_add_driver(&lm90_driver);
643}
644
645static void __exit sensors_lm90_exit(void)
646{
647 i2c_del_driver(&lm90_driver);
648}
649
650MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
651MODULE_DESCRIPTION("LM90/ADM1032 driver");
652MODULE_LICENSE("GPL");
653
654module_init(sensors_lm90_init);
655module_exit(sensors_lm90_exit);
generated by cgit v1.2.2 (git 2.25.0) at 2025-11-02 17:50:46 -0500