2 * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
4 * Copyright (C) 2003-2006 Jean Delvare <khali@linux-fr.org>
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
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.
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
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
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.
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
52 * http://www.analog.com/en/prod/0,2877,ADT7461,00.html
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.
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.
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.
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.
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>
85 * Address is fully defined internally and cannot be changed except for
87 * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, MAX6657 and MAX6658
89 * ADM1032-2, ADT7461-2, LM89-1, and LM99-1 have address 0x4d.
90 * MAX6659 can have address 0x4c, 0x4d or 0x4e (unsupported).
93 static unsigned short normal_i2c[] = { 0x4c, 0x4d, I2C_CLIENT_END };
99 I2C_CLIENT_INSMOD_6(lm90, adm1032, lm99, lm86, max6657, adt7461);
105 #define LM90_REG_R_MAN_ID 0xFE
106 #define LM90_REG_R_CHIP_ID 0xFF
107 #define LM90_REG_R_CONFIG1 0x03
108 #define LM90_REG_W_CONFIG1 0x09
109 #define LM90_REG_R_CONFIG2 0xBF
110 #define LM90_REG_W_CONFIG2 0xBF
111 #define LM90_REG_R_CONVRATE 0x04
112 #define LM90_REG_W_CONVRATE 0x0A
113 #define LM90_REG_R_STATUS 0x02
114 #define LM90_REG_R_LOCAL_TEMP 0x00
115 #define LM90_REG_R_LOCAL_HIGH 0x05
116 #define LM90_REG_W_LOCAL_HIGH 0x0B
117 #define LM90_REG_R_LOCAL_LOW 0x06
118 #define LM90_REG_W_LOCAL_LOW 0x0C
119 #define LM90_REG_R_LOCAL_CRIT 0x20
120 #define LM90_REG_W_LOCAL_CRIT 0x20
121 #define LM90_REG_R_REMOTE_TEMPH 0x01
122 #define LM90_REG_R_REMOTE_TEMPL 0x10
123 #define LM90_REG_R_REMOTE_OFFSH 0x11
124 #define LM90_REG_W_REMOTE_OFFSH 0x11
125 #define LM90_REG_R_REMOTE_OFFSL 0x12
126 #define LM90_REG_W_REMOTE_OFFSL 0x12
127 #define LM90_REG_R_REMOTE_HIGHH 0x07
128 #define LM90_REG_W_REMOTE_HIGHH 0x0D
129 #define LM90_REG_R_REMOTE_HIGHL 0x13
130 #define LM90_REG_W_REMOTE_HIGHL 0x13
131 #define LM90_REG_R_REMOTE_LOWH 0x08
132 #define LM90_REG_W_REMOTE_LOWH 0x0E
133 #define LM90_REG_R_REMOTE_LOWL 0x14
134 #define LM90_REG_W_REMOTE_LOWL 0x14
135 #define LM90_REG_R_REMOTE_CRIT 0x19
136 #define LM90_REG_W_REMOTE_CRIT 0x19
137 #define LM90_REG_R_TCRIT_HYST 0x21
138 #define LM90_REG_W_TCRIT_HYST 0x21
141 * Conversions and various macros
142 * For local temperatures and limits, critical limits and the hysteresis
143 * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
144 * For remote temperatures and limits, it uses signed 11-bit values with
145 * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.
148 #define TEMP1_FROM_REG(val) ((val) * 1000)
149 #define TEMP1_TO_REG(val) ((val) <= -128000 ? -128 : \
150 (val) >= 127000 ? 127 : \
151 (val) < 0 ? ((val) - 500) / 1000 : \
152 ((val) + 500) / 1000)
153 #define TEMP2_FROM_REG(val) ((val) / 32 * 125)
154 #define TEMP2_TO_REG(val) ((val) <= -128000 ? 0x8000 : \
155 (val) >= 127875 ? 0x7FE0 : \
156 (val) < 0 ? ((val) - 62) / 125 * 32 : \
157 ((val) + 62) / 125 * 32)
158 #define HYST_TO_REG(val) ((val) <= 0 ? 0 : (val) >= 30500 ? 31 : \
159 ((val) + 500) / 1000)
162 * ADT7461 is almost identical to LM90 except that attempts to write
163 * values that are outside the range 0 < temp < 127 are treated as
164 * the boundary value.
167 #define TEMP1_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
168 (val) >= 127000 ? 127 : \
169 ((val) + 500) / 1000)
170 #define TEMP2_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
171 (val) >= 127750 ? 0x7FC0 : \
172 ((val) + 125) / 250 * 64)
175 * Functions declaration
178 static int lm90_attach_adapter(struct i2c_adapter *adapter);
179 static int lm90_detect(struct i2c_adapter *adapter, int address,
181 static void lm90_init_client(struct i2c_client *client);
182 static int lm90_detach_client(struct i2c_client *client);
183 static struct lm90_data *lm90_update_device(struct device *dev);
186 * Driver data (common to all clients)
189 static struct i2c_driver lm90_driver = {
193 .id = I2C_DRIVERID_LM90,
194 .attach_adapter = lm90_attach_adapter,
195 .detach_client = lm90_detach_client,
199 * Client data (each client gets its own)
203 struct i2c_client client;
204 struct class_device *class_dev;
205 struct mutex update_lock;
206 char valid; /* zero until following fields are valid */
207 unsigned long last_updated; /* in jiffies */
210 /* registers values */
211 s8 temp8[5]; /* 0: local input
214 3: local critical limit
215 4: remote critical limit */
216 s16 temp11[3]; /* 0: remote input
218 2: remote high limit */
220 u8 alarms; /* bitvector */
227 static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
230 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
231 struct lm90_data *data = lm90_update_device(dev);
232 return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index]));
235 static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
236 const char *buf, size_t count)
238 static const u8 reg[4] = {
239 LM90_REG_W_LOCAL_LOW,
240 LM90_REG_W_LOCAL_HIGH,
241 LM90_REG_W_LOCAL_CRIT,
242 LM90_REG_W_REMOTE_CRIT,
245 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
246 struct i2c_client *client = to_i2c_client(dev);
247 struct lm90_data *data = i2c_get_clientdata(client);
248 long val = simple_strtol(buf, NULL, 10);
249 int nr = attr->index;
251 mutex_lock(&data->update_lock);
252 if (data->kind == adt7461)
253 data->temp8[nr] = TEMP1_TO_REG_ADT7461(val);
255 data->temp8[nr] = TEMP1_TO_REG(val);
256 i2c_smbus_write_byte_data(client, reg[nr - 1], data->temp8[nr]);
257 mutex_unlock(&data->update_lock);
261 static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
264 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
265 struct lm90_data *data = lm90_update_device(dev);
266 return sprintf(buf, "%d\n", TEMP2_FROM_REG(data->temp11[attr->index]));
269 static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
270 const char *buf, size_t count)
272 static const u8 reg[4] = {
273 LM90_REG_W_REMOTE_LOWH,
274 LM90_REG_W_REMOTE_LOWL,
275 LM90_REG_W_REMOTE_HIGHH,
276 LM90_REG_W_REMOTE_HIGHL,
279 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
280 struct i2c_client *client = to_i2c_client(dev);
281 struct lm90_data *data = i2c_get_clientdata(client);
282 long val = simple_strtol(buf, NULL, 10);
283 int nr = attr->index;
285 mutex_lock(&data->update_lock);
286 if (data->kind == adt7461)
287 data->temp11[nr] = TEMP2_TO_REG_ADT7461(val);
289 data->temp11[nr] = TEMP2_TO_REG(val);
290 i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
291 data->temp11[nr] >> 8);
292 i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
293 data->temp11[nr] & 0xff);
294 mutex_unlock(&data->update_lock);
298 static ssize_t show_temphyst(struct device *dev, struct device_attribute *devattr,
301 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
302 struct lm90_data *data = lm90_update_device(dev);
303 return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index])
304 - TEMP1_FROM_REG(data->temp_hyst));
307 static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
308 const char *buf, size_t count)
310 struct i2c_client *client = to_i2c_client(dev);
311 struct lm90_data *data = i2c_get_clientdata(client);
312 long val = simple_strtol(buf, NULL, 10);
315 mutex_lock(&data->update_lock);
316 hyst = TEMP1_FROM_REG(data->temp8[3]) - val;
317 i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
319 mutex_unlock(&data->update_lock);
323 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
326 struct lm90_data *data = lm90_update_device(dev);
327 return sprintf(buf, "%d\n", data->alarms);
330 static ssize_t show_alarm(struct device *dev, struct device_attribute
333 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
334 struct lm90_data *data = lm90_update_device(dev);
335 int bitnr = attr->index;
337 return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
340 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp8, NULL, 0);
341 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp11, NULL, 0);
342 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
344 static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
346 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
348 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
350 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
352 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
354 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
356 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 4);
358 /* Individual alarm files */
359 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
360 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
361 static SENSOR_DEVICE_ATTR(temp2_input_fault, S_IRUGO, show_alarm, NULL, 2);
362 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
363 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
364 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 5);
365 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
366 /* Raw alarm file for compatibility */
367 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
369 /* pec used for ADM1032 only */
370 static ssize_t show_pec(struct device *dev, struct device_attribute *dummy,
373 struct i2c_client *client = to_i2c_client(dev);
374 return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
377 static ssize_t set_pec(struct device *dev, struct device_attribute *dummy,
378 const char *buf, size_t count)
380 struct i2c_client *client = to_i2c_client(dev);
381 long val = simple_strtol(buf, NULL, 10);
385 client->flags &= ~I2C_CLIENT_PEC;
388 client->flags |= I2C_CLIENT_PEC;
397 static DEVICE_ATTR(pec, S_IWUSR | S_IRUGO, show_pec, set_pec);
403 /* The ADM1032 supports PEC but not on write byte transactions, so we need
404 to explicitely ask for a transaction without PEC. */
405 static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value)
407 return i2c_smbus_xfer(client->adapter, client->addr,
408 client->flags & ~I2C_CLIENT_PEC,
409 I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
412 /* It is assumed that client->update_lock is held (unless we are in
413 detection or initialization steps). This matters when PEC is enabled,
414 because we don't want the address pointer to change between the write
415 byte and the read byte transactions. */
416 static int lm90_read_reg(struct i2c_client* client, u8 reg, u8 *value)
420 if (client->flags & I2C_CLIENT_PEC) {
421 err = adm1032_write_byte(client, reg);
423 err = i2c_smbus_read_byte(client);
425 err = i2c_smbus_read_byte_data(client, reg);
428 dev_warn(&client->dev, "Register %#02x read failed (%d)\n",
437 static int lm90_attach_adapter(struct i2c_adapter *adapter)
439 if (!(adapter->class & I2C_CLASS_HWMON))
441 return i2c_probe(adapter, &addr_data, lm90_detect);
445 * The following function does more than just detection. If detection
446 * succeeds, it also registers the new chip.
448 static int lm90_detect(struct i2c_adapter *adapter, int address, int kind)
450 struct i2c_client *new_client;
451 struct lm90_data *data;
453 const char *name = "";
455 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
458 if (!(data = kzalloc(sizeof(struct lm90_data), GFP_KERNEL))) {
463 /* The common I2C client data is placed right before the
464 LM90-specific data. */
465 new_client = &data->client;
466 i2c_set_clientdata(new_client, data);
467 new_client->addr = address;
468 new_client->adapter = adapter;
469 new_client->driver = &lm90_driver;
470 new_client->flags = 0;
473 * Now we do the remaining detection. A negative kind means that
474 * the driver was loaded with no force parameter (default), so we
475 * must both detect and identify the chip. A zero kind means that
476 * the driver was loaded with the force parameter, the detection
477 * step shall be skipped. A positive kind means that the driver
478 * was loaded with the force parameter and a given kind of chip is
479 * requested, so both the detection and the identification steps
483 /* Default to an LM90 if forced */
487 if (kind < 0) { /* detection and identification */
488 u8 man_id, chip_id, reg_config1, reg_convrate;
490 if (lm90_read_reg(new_client, LM90_REG_R_MAN_ID,
492 || lm90_read_reg(new_client, LM90_REG_R_CHIP_ID,
494 || lm90_read_reg(new_client, LM90_REG_R_CONFIG1,
496 || lm90_read_reg(new_client, LM90_REG_R_CONVRATE,
500 if (man_id == 0x01) { /* National Semiconductor */
503 if (lm90_read_reg(new_client, LM90_REG_R_CONFIG2,
507 if ((reg_config1 & 0x2A) == 0x00
508 && (reg_config2 & 0xF8) == 0x00
509 && reg_convrate <= 0x09) {
511 && (chip_id & 0xF0) == 0x20) { /* LM90 */
514 if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
518 && (chip_id & 0xF0) == 0x10) { /* LM86 */
523 if (man_id == 0x41) { /* Analog Devices */
524 if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
525 && (reg_config1 & 0x3F) == 0x00
526 && reg_convrate <= 0x0A) {
529 if (chip_id == 0x51 /* ADT7461 */
530 && (reg_config1 & 0x1F) == 0x00 /* check compat mode */
531 && reg_convrate <= 0x0A) {
535 if (man_id == 0x4D) { /* Maxim */
537 * The Maxim variants do NOT have a chip_id register.
538 * Reading from that address will return the last read
539 * value, which in our case is those of the man_id
540 * register. Likewise, the config1 register seems to
541 * lack a low nibble, so the value will be those of the
542 * previous read, so in our case those of the man_id
545 if (chip_id == man_id
546 && (reg_config1 & 0x1F) == (man_id & 0x0F)
547 && reg_convrate <= 0x09) {
552 if (kind <= 0) { /* identification failed */
553 dev_info(&adapter->dev,
554 "Unsupported chip (man_id=0x%02X, "
555 "chip_id=0x%02X).\n", man_id, chip_id);
562 } else if (kind == adm1032) {
564 /* The ADM1032 supports PEC, but only if combined
565 transactions are not used. */
566 if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
567 new_client->flags |= I2C_CLIENT_PEC;
568 } else if (kind == lm99) {
570 } else if (kind == lm86) {
572 } else if (kind == max6657) {
574 } else if (kind == adt7461) {
578 /* We can fill in the remaining client fields */
579 strlcpy(new_client->name, name, I2C_NAME_SIZE);
582 mutex_init(&data->update_lock);
584 /* Tell the I2C layer a new client has arrived */
585 if ((err = i2c_attach_client(new_client)))
588 /* Initialize the LM90 chip */
589 lm90_init_client(new_client);
591 /* Register sysfs hooks */
592 data->class_dev = hwmon_device_register(&new_client->dev);
593 if (IS_ERR(data->class_dev)) {
594 err = PTR_ERR(data->class_dev);
598 device_create_file(&new_client->dev,
599 &sensor_dev_attr_temp1_input.dev_attr);
600 device_create_file(&new_client->dev,
601 &sensor_dev_attr_temp2_input.dev_attr);
602 device_create_file(&new_client->dev,
603 &sensor_dev_attr_temp1_min.dev_attr);
604 device_create_file(&new_client->dev,
605 &sensor_dev_attr_temp2_min.dev_attr);
606 device_create_file(&new_client->dev,
607 &sensor_dev_attr_temp1_max.dev_attr);
608 device_create_file(&new_client->dev,
609 &sensor_dev_attr_temp2_max.dev_attr);
610 device_create_file(&new_client->dev,
611 &sensor_dev_attr_temp1_crit.dev_attr);
612 device_create_file(&new_client->dev,
613 &sensor_dev_attr_temp2_crit.dev_attr);
614 device_create_file(&new_client->dev,
615 &sensor_dev_attr_temp1_crit_hyst.dev_attr);
616 device_create_file(&new_client->dev,
617 &sensor_dev_attr_temp2_crit_hyst.dev_attr);
619 device_create_file(&new_client->dev,
620 &sensor_dev_attr_temp2_input_fault.dev_attr);
621 device_create_file(&new_client->dev,
622 &sensor_dev_attr_temp1_min_alarm.dev_attr);
623 device_create_file(&new_client->dev,
624 &sensor_dev_attr_temp2_min_alarm.dev_attr);
625 device_create_file(&new_client->dev,
626 &sensor_dev_attr_temp1_max_alarm.dev_attr);
627 device_create_file(&new_client->dev,
628 &sensor_dev_attr_temp2_max_alarm.dev_attr);
629 device_create_file(&new_client->dev,
630 &sensor_dev_attr_temp1_crit_alarm.dev_attr);
631 device_create_file(&new_client->dev,
632 &sensor_dev_attr_temp2_crit_alarm.dev_attr);
633 device_create_file(&new_client->dev, &dev_attr_alarms);
635 if (new_client->flags & I2C_CLIENT_PEC)
636 device_create_file(&new_client->dev, &dev_attr_pec);
641 i2c_detach_client(new_client);
648 static void lm90_init_client(struct i2c_client *client)
653 * Start the conversions.
655 i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
657 if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) {
658 dev_warn(&client->dev, "Initialization failed!\n");
662 i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
663 config & 0xBF); /* run */
666 static int lm90_detach_client(struct i2c_client *client)
668 struct lm90_data *data = i2c_get_clientdata(client);
671 hwmon_device_unregister(data->class_dev);
673 if ((err = i2c_detach_client(client)))
680 static struct lm90_data *lm90_update_device(struct device *dev)
682 struct i2c_client *client = to_i2c_client(dev);
683 struct lm90_data *data = i2c_get_clientdata(client);
685 mutex_lock(&data->update_lock);
687 if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
690 dev_dbg(&client->dev, "Updating lm90 data.\n");
691 lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP, &data->temp8[0]);
692 lm90_read_reg(client, LM90_REG_R_LOCAL_LOW, &data->temp8[1]);
693 lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH, &data->temp8[2]);
694 lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT, &data->temp8[3]);
695 lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[4]);
696 lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
699 * There is a trick here. We have to read two registers to
700 * have the remote sensor temperature, but we have to beware
701 * a conversion could occur inbetween the readings. The
702 * datasheet says we should either use the one-shot
703 * conversion register, which we don't want to do (disables
704 * hardware monitoring) or monitor the busy bit, which is
705 * impossible (we can't read the values and monitor that bit
706 * at the exact same time). So the solution used here is to
707 * read the high byte once, then the low byte, then the high
708 * byte again. If the new high byte matches the old one,
709 * then we have a valid reading. Else we have to read the low
710 * byte again, and now we believe we have a correct reading.
712 if (lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPH, &oldh) == 0
713 && lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPL, &l) == 0
714 && lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPH, &newh) == 0
716 || lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPL, &l) == 0))
717 data->temp11[0] = (newh << 8) | l;
719 if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &newh) == 0
720 && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL, &l) == 0)
721 data->temp11[1] = (newh << 8) | l;
722 if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &newh) == 0
723 && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL, &l) == 0)
724 data->temp11[2] = (newh << 8) | l;
725 lm90_read_reg(client, LM90_REG_R_STATUS, &data->alarms);
727 data->last_updated = jiffies;
731 mutex_unlock(&data->update_lock);
736 static int __init sensors_lm90_init(void)
738 return i2c_add_driver(&lm90_driver);
741 static void __exit sensors_lm90_exit(void)
743 i2c_del_driver(&lm90_driver);
746 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
747 MODULE_DESCRIPTION("LM90/ADM1032 driver");
748 MODULE_LICENSE("GPL");
750 module_init(sensors_lm90_init);
751 module_exit(sensors_lm90_exit);