[PATCH] hwmon: Separate the lm90 register read function
[deliverable/linux.git] / drivers / hwmon / lm90.c
CommitLineData
1da177e4
LT
1/*
2 * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
3 * monitoring
30d7394b 4 * Copyright (C) 2003-2005 Jean Delvare <khali@linux-fr.org>
1da177e4
LT
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
44bbe87e 22 * Note that there is no way to differentiate between both chips.
1da177e4
LT
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
44bbe87e 42 * Note that there is no easy way to differentiate between the three
1da177e4
LT
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
1da177e4
LT
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>
10c08f81 78#include <linux/hwmon-sysfs.h>
943b0830
MH
79#include <linux/hwmon.h>
80#include <linux/err.h>
1da177e4
LT
81
82/*
83 * Addresses to scan
84 * Address is fully defined internally and cannot be changed except for
85 * MAX6659.
86 * LM86, LM89, LM90, LM99, ADM1032, MAX6657 and MAX6658 have address 0x4c.
87 * LM89-1, and LM99-1 have address 0x4d.
88 * MAX6659 can have address 0x4c, 0x4d or 0x4e (unsupported).
89 * ADT7461 always has address 0x4c.
90 */
91
92static unsigned short normal_i2c[] = { 0x4c, 0x4d, I2C_CLIENT_END };
1da177e4
LT
93
94/*
95 * Insmod parameters
96 */
97
f4b50261 98I2C_CLIENT_INSMOD_6(lm90, adm1032, lm99, lm86, max6657, adt7461);
1da177e4
LT
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
44bbe87e 142 * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
1da177e4 143 * For remote temperatures and limits, it uses signed 11-bit values with
44bbe87e 144 * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.
1da177e4
LT
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;
943b0830 203 struct class_device *class_dev;
1da177e4
LT
204 struct semaphore update_lock;
205 char valid; /* zero until following fields are valid */
206 unsigned long last_updated; /* in jiffies */
207 int kind;
208
209 /* registers values */
30d7394b
JD
210 s8 temp8[5]; /* 0: local input
211 1: local low limit
212 2: local high limit
213 3: local critical limit
214 4: remote critical limit */
215 s16 temp11[3]; /* 0: remote input
216 1: remote low limit
217 2: remote high limit */
1da177e4
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218 u8 temp_hyst;
219 u8 alarms; /* bitvector */
220};
221
222/*
223 * Sysfs stuff
224 */
225
30d7394b
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226static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
227 char *buf)
228{
229 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
230 struct lm90_data *data = lm90_update_device(dev);
231 return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index]));
232}
233
234static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
235 const char *buf, size_t count)
236{
237 static const u8 reg[4] = {
238 LM90_REG_W_LOCAL_LOW,
239 LM90_REG_W_LOCAL_HIGH,
240 LM90_REG_W_LOCAL_CRIT,
241 LM90_REG_W_REMOTE_CRIT,
242 };
243
244 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
245 struct i2c_client *client = to_i2c_client(dev);
246 struct lm90_data *data = i2c_get_clientdata(client);
247 long val = simple_strtol(buf, NULL, 10);
248 int nr = attr->index;
249
250 down(&data->update_lock);
251 if (data->kind == adt7461)
252 data->temp8[nr] = TEMP1_TO_REG_ADT7461(val);
253 else
254 data->temp8[nr] = TEMP1_TO_REG(val);
255 i2c_smbus_write_byte_data(client, reg[nr - 1], data->temp8[nr]);
256 up(&data->update_lock);
257 return count;
1da177e4 258}
30d7394b
JD
259
260static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
261 char *buf)
262{
263 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
264 struct lm90_data *data = lm90_update_device(dev);
265 return sprintf(buf, "%d\n", TEMP2_FROM_REG(data->temp11[attr->index]));
1da177e4 266}
30d7394b
JD
267
268static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
269 const char *buf, size_t count)
270{
271 static const u8 reg[4] = {
272 LM90_REG_W_REMOTE_LOWH,
273 LM90_REG_W_REMOTE_LOWL,
274 LM90_REG_W_REMOTE_HIGHH,
275 LM90_REG_W_REMOTE_HIGHL,
276 };
277
278 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
279 struct i2c_client *client = to_i2c_client(dev);
280 struct lm90_data *data = i2c_get_clientdata(client);
281 long val = simple_strtol(buf, NULL, 10);
282 int nr = attr->index;
283
284 down(&data->update_lock);
285 if (data->kind == adt7461)
286 data->temp11[nr] = TEMP2_TO_REG_ADT7461(val);
287 else
288 data->temp11[nr] = TEMP2_TO_REG(val);
289 i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
290 data->temp11[nr] >> 8);
291 i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
292 data->temp11[nr] & 0xff);
293 up(&data->update_lock);
294 return count;
1da177e4 295}
30d7394b
JD
296
297static ssize_t show_temphyst(struct device *dev, struct device_attribute *devattr,
298 char *buf)
299{
300 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
301 struct lm90_data *data = lm90_update_device(dev);
302 return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index])
303 - TEMP1_FROM_REG(data->temp_hyst));
1da177e4 304}
1da177e4 305
30d7394b
JD
306static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
307 const char *buf, size_t count)
1da177e4
LT
308{
309 struct i2c_client *client = to_i2c_client(dev);
310 struct lm90_data *data = i2c_get_clientdata(client);
311 long val = simple_strtol(buf, NULL, 10);
312 long hyst;
313
314 down(&data->update_lock);
30d7394b 315 hyst = TEMP1_FROM_REG(data->temp8[3]) - val;
1da177e4
LT
316 i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
317 HYST_TO_REG(hyst));
318 up(&data->update_lock);
319 return count;
320}
321
30d7394b
JD
322static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
323 char *buf)
1da177e4
LT
324{
325 struct lm90_data *data = lm90_update_device(dev);
326 return sprintf(buf, "%d\n", data->alarms);
327}
328
30d7394b
JD
329static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp8, NULL, 0);
330static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp11, NULL, 0);
331static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
332 set_temp8, 1);
333static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
334 set_temp11, 1);
335static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
336 set_temp8, 2);
337static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
338 set_temp11, 2);
339static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
340 set_temp8, 3);
341static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
342 set_temp8, 4);
343static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
344 set_temphyst, 3);
345static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 4);
1da177e4
LT
346static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
347
348/*
349 * Real code
350 */
351
8256fe0f
JD
352static int lm90_read_reg(struct i2c_client* client, u8 reg, u8 *value)
353{
354 int err;
355
356 err = i2c_smbus_read_byte_data(client, reg);
357
358 if (err < 0) {
359 dev_warn(&client->dev, "Register %#02x read failed (%d)\n",
360 reg, err);
361 return err;
362 }
363 *value = err;
364
365 return 0;
366}
367
1da177e4
LT
368static int lm90_attach_adapter(struct i2c_adapter *adapter)
369{
370 if (!(adapter->class & I2C_CLASS_HWMON))
371 return 0;
2ed2dc3c 372 return i2c_probe(adapter, &addr_data, lm90_detect);
1da177e4
LT
373}
374
375/*
376 * The following function does more than just detection. If detection
377 * succeeds, it also registers the new chip.
378 */
379static int lm90_detect(struct i2c_adapter *adapter, int address, int kind)
380{
381 struct i2c_client *new_client;
382 struct lm90_data *data;
383 int err = 0;
384 const char *name = "";
385
386 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
387 goto exit;
388
ba9c2e8d 389 if (!(data = kzalloc(sizeof(struct lm90_data), GFP_KERNEL))) {
1da177e4
LT
390 err = -ENOMEM;
391 goto exit;
392 }
1da177e4
LT
393
394 /* The common I2C client data is placed right before the
395 LM90-specific data. */
396 new_client = &data->client;
397 i2c_set_clientdata(new_client, data);
398 new_client->addr = address;
399 new_client->adapter = adapter;
400 new_client->driver = &lm90_driver;
401 new_client->flags = 0;
402
403 /*
404 * Now we do the remaining detection. A negative kind means that
405 * the driver was loaded with no force parameter (default), so we
406 * must both detect and identify the chip. A zero kind means that
407 * the driver was loaded with the force parameter, the detection
408 * step shall be skipped. A positive kind means that the driver
409 * was loaded with the force parameter and a given kind of chip is
410 * requested, so both the detection and the identification steps
411 * are skipped.
412 */
413
414 /* Default to an LM90 if forced */
415 if (kind == 0)
416 kind = lm90;
417
418 if (kind < 0) { /* detection and identification */
419 u8 man_id, chip_id, reg_config1, reg_convrate;
420
8256fe0f
JD
421 if (lm90_read_reg(new_client, LM90_REG_R_MAN_ID,
422 &man_id) < 0
423 || lm90_read_reg(new_client, LM90_REG_R_CHIP_ID,
424 &chip_id) < 0
425 || lm90_read_reg(new_client, LM90_REG_R_CONFIG1,
426 &reg_config1) < 0
427 || lm90_read_reg(new_client, LM90_REG_R_CONVRATE,
428 &reg_convrate) < 0)
429 goto exit_free;
1da177e4
LT
430
431 if (man_id == 0x01) { /* National Semiconductor */
432 u8 reg_config2;
433
8256fe0f
JD
434 if (lm90_read_reg(new_client, LM90_REG_R_CONFIG2,
435 &reg_config2) < 0)
436 goto exit_free;
1da177e4
LT
437
438 if ((reg_config1 & 0x2A) == 0x00
439 && (reg_config2 & 0xF8) == 0x00
440 && reg_convrate <= 0x09) {
441 if (address == 0x4C
442 && (chip_id & 0xF0) == 0x20) { /* LM90 */
443 kind = lm90;
444 } else
445 if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
446 kind = lm99;
447 } else
448 if (address == 0x4C
449 && (chip_id & 0xF0) == 0x10) { /* LM86 */
450 kind = lm86;
451 }
452 }
453 } else
454 if (man_id == 0x41) { /* Analog Devices */
455 if (address == 0x4C
456 && (chip_id & 0xF0) == 0x40 /* ADM1032 */
457 && (reg_config1 & 0x3F) == 0x00
458 && reg_convrate <= 0x0A) {
459 kind = adm1032;
460 } else
461 if (address == 0x4c
462 && chip_id == 0x51 /* ADT7461 */
463 && (reg_config1 & 0x1F) == 0x00 /* check compat mode */
464 && reg_convrate <= 0x0A) {
465 kind = adt7461;
466 }
467 } else
468 if (man_id == 0x4D) { /* Maxim */
469 /*
470 * The Maxim variants do NOT have a chip_id register.
471 * Reading from that address will return the last read
472 * value, which in our case is those of the man_id
473 * register. Likewise, the config1 register seems to
474 * lack a low nibble, so the value will be those of the
475 * previous read, so in our case those of the man_id
476 * register.
477 */
478 if (chip_id == man_id
479 && (reg_config1 & 0x1F) == (man_id & 0x0F)
480 && reg_convrate <= 0x09) {
481 kind = max6657;
482 }
483 }
484
485 if (kind <= 0) { /* identification failed */
486 dev_info(&adapter->dev,
487 "Unsupported chip (man_id=0x%02X, "
488 "chip_id=0x%02X).\n", man_id, chip_id);
489 goto exit_free;
490 }
491 }
492
493 if (kind == lm90) {
494 name = "lm90";
495 } else if (kind == adm1032) {
496 name = "adm1032";
497 } else if (kind == lm99) {
498 name = "lm99";
499 } else if (kind == lm86) {
500 name = "lm86";
501 } else if (kind == max6657) {
502 name = "max6657";
503 } else if (kind == adt7461) {
504 name = "adt7461";
505 }
506
507 /* We can fill in the remaining client fields */
508 strlcpy(new_client->name, name, I2C_NAME_SIZE);
509 data->valid = 0;
510 data->kind = kind;
511 init_MUTEX(&data->update_lock);
512
513 /* Tell the I2C layer a new client has arrived */
514 if ((err = i2c_attach_client(new_client)))
515 goto exit_free;
516
517 /* Initialize the LM90 chip */
518 lm90_init_client(new_client);
519
520 /* Register sysfs hooks */
943b0830
MH
521 data->class_dev = hwmon_device_register(&new_client->dev);
522 if (IS_ERR(data->class_dev)) {
523 err = PTR_ERR(data->class_dev);
524 goto exit_detach;
525 }
526
30d7394b
JD
527 device_create_file(&new_client->dev,
528 &sensor_dev_attr_temp1_input.dev_attr);
529 device_create_file(&new_client->dev,
530 &sensor_dev_attr_temp2_input.dev_attr);
531 device_create_file(&new_client->dev,
532 &sensor_dev_attr_temp1_min.dev_attr);
533 device_create_file(&new_client->dev,
534 &sensor_dev_attr_temp2_min.dev_attr);
535 device_create_file(&new_client->dev,
536 &sensor_dev_attr_temp1_max.dev_attr);
537 device_create_file(&new_client->dev,
538 &sensor_dev_attr_temp2_max.dev_attr);
539 device_create_file(&new_client->dev,
540 &sensor_dev_attr_temp1_crit.dev_attr);
541 device_create_file(&new_client->dev,
542 &sensor_dev_attr_temp2_crit.dev_attr);
543 device_create_file(&new_client->dev,
544 &sensor_dev_attr_temp1_crit_hyst.dev_attr);
545 device_create_file(&new_client->dev,
546 &sensor_dev_attr_temp2_crit_hyst.dev_attr);
1da177e4
LT
547 device_create_file(&new_client->dev, &dev_attr_alarms);
548
549 return 0;
550
943b0830
MH
551exit_detach:
552 i2c_detach_client(new_client);
1da177e4
LT
553exit_free:
554 kfree(data);
555exit:
556 return err;
557}
558
559static void lm90_init_client(struct i2c_client *client)
560{
561 u8 config;
562
563 /*
564 * Start the conversions.
565 */
566 i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
567 5); /* 2 Hz */
8256fe0f
JD
568 if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) {
569 dev_warn(&client->dev, "Initialization failed!\n");
570 return;
571 }
1da177e4
LT
572 if (config & 0x40)
573 i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
574 config & 0xBF); /* run */
575}
576
577static int lm90_detach_client(struct i2c_client *client)
578{
943b0830 579 struct lm90_data *data = i2c_get_clientdata(client);
1da177e4
LT
580 int err;
581
943b0830
MH
582 hwmon_device_unregister(data->class_dev);
583
7bef5594 584 if ((err = i2c_detach_client(client)))
1da177e4 585 return err;
1da177e4 586
943b0830 587 kfree(data);
1da177e4
LT
588 return 0;
589}
590
591static struct lm90_data *lm90_update_device(struct device *dev)
592{
593 struct i2c_client *client = to_i2c_client(dev);
594 struct lm90_data *data = i2c_get_clientdata(client);
595
596 down(&data->update_lock);
597
598 if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
8256fe0f 599 u8 oldh, newh, l;
1da177e4
LT
600
601 dev_dbg(&client->dev, "Updating lm90 data.\n");
8256fe0f
JD
602 lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP, &data->temp8[0]);
603 lm90_read_reg(client, LM90_REG_R_LOCAL_LOW, &data->temp8[1]);
604 lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH, &data->temp8[2]);
605 lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT, &data->temp8[3]);
606 lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[4]);
607 lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
1da177e4
LT
608
609 /*
610 * There is a trick here. We have to read two registers to
611 * have the remote sensor temperature, but we have to beware
612 * a conversion could occur inbetween the readings. The
613 * datasheet says we should either use the one-shot
614 * conversion register, which we don't want to do (disables
615 * hardware monitoring) or monitor the busy bit, which is
616 * impossible (we can't read the values and monitor that bit
617 * at the exact same time). So the solution used here is to
618 * read the high byte once, then the low byte, then the high
619 * byte again. If the new high byte matches the old one,
620 * then we have a valid reading. Else we have to read the low
621 * byte again, and now we believe we have a correct reading.
622 */
8256fe0f
JD
623 if (lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPH, &oldh) == 0
624 && lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPL, &l) == 0
625 && lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPH, &newh) == 0
626 && (newh == oldh
627 || lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPL, &l) == 0))
628 data->temp11[0] = (newh << 8) | l;
629
630 if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &newh) == 0
631 && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL, &l) == 0)
632 data->temp11[1] = (newh << 8) | l;
633 if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &newh) == 0
634 && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL, &l) == 0)
635 data->temp11[2] = (newh << 8) | l;
636 lm90_read_reg(client, LM90_REG_R_STATUS, &data->alarms);
1da177e4
LT
637
638 data->last_updated = jiffies;
639 data->valid = 1;
640 }
641
642 up(&data->update_lock);
643
644 return data;
645}
646
647static int __init sensors_lm90_init(void)
648{
649 return i2c_add_driver(&lm90_driver);
650}
651
652static void __exit sensors_lm90_exit(void)
653{
654 i2c_del_driver(&lm90_driver);
655}
656
657MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
658MODULE_DESCRIPTION("LM90/ADM1032 driver");
659MODULE_LICENSE("GPL");
660
661module_init(sensors_lm90_init);
662module_exit(sensors_lm90_exit);
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