lm90.c 21 KB

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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. #include <linux/module.h>
  73. #include <linux/init.h>
  74. #include <linux/slab.h>
  75. #include <linux/jiffies.h>
  76. #include <linux/i2c.h>
  77. #include <linux/i2c-sensor.h>
  78. #include <linux/hwmon-sysfs.h>
  79. #include <linux/hwmon.h>
  80. #include <linux/err.h>
  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. static unsigned short normal_i2c[] = { 0x4c, 0x4d, I2C_CLIENT_END };
  91. /*
  92. * Insmod parameters
  93. */
  94. SENSORS_INSMOD_6(lm90, adm1032, lm99, lm86, max6657, adt7461);
  95. /*
  96. * The LM90 registers
  97. */
  98. #define LM90_REG_R_MAN_ID 0xFE
  99. #define LM90_REG_R_CHIP_ID 0xFF
  100. #define LM90_REG_R_CONFIG1 0x03
  101. #define LM90_REG_W_CONFIG1 0x09
  102. #define LM90_REG_R_CONFIG2 0xBF
  103. #define LM90_REG_W_CONFIG2 0xBF
  104. #define LM90_REG_R_CONVRATE 0x04
  105. #define LM90_REG_W_CONVRATE 0x0A
  106. #define LM90_REG_R_STATUS 0x02
  107. #define LM90_REG_R_LOCAL_TEMP 0x00
  108. #define LM90_REG_R_LOCAL_HIGH 0x05
  109. #define LM90_REG_W_LOCAL_HIGH 0x0B
  110. #define LM90_REG_R_LOCAL_LOW 0x06
  111. #define LM90_REG_W_LOCAL_LOW 0x0C
  112. #define LM90_REG_R_LOCAL_CRIT 0x20
  113. #define LM90_REG_W_LOCAL_CRIT 0x20
  114. #define LM90_REG_R_REMOTE_TEMPH 0x01
  115. #define LM90_REG_R_REMOTE_TEMPL 0x10
  116. #define LM90_REG_R_REMOTE_OFFSH 0x11
  117. #define LM90_REG_W_REMOTE_OFFSH 0x11
  118. #define LM90_REG_R_REMOTE_OFFSL 0x12
  119. #define LM90_REG_W_REMOTE_OFFSL 0x12
  120. #define LM90_REG_R_REMOTE_HIGHH 0x07
  121. #define LM90_REG_W_REMOTE_HIGHH 0x0D
  122. #define LM90_REG_R_REMOTE_HIGHL 0x13
  123. #define LM90_REG_W_REMOTE_HIGHL 0x13
  124. #define LM90_REG_R_REMOTE_LOWH 0x08
  125. #define LM90_REG_W_REMOTE_LOWH 0x0E
  126. #define LM90_REG_R_REMOTE_LOWL 0x14
  127. #define LM90_REG_W_REMOTE_LOWL 0x14
  128. #define LM90_REG_R_REMOTE_CRIT 0x19
  129. #define LM90_REG_W_REMOTE_CRIT 0x19
  130. #define LM90_REG_R_TCRIT_HYST 0x21
  131. #define LM90_REG_W_TCRIT_HYST 0x21
  132. /*
  133. * Conversions and various macros
  134. * For local temperatures and limits, critical limits and the hysteresis
  135. * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
  136. * For remote temperatures and limits, it uses signed 11-bit values with
  137. * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.
  138. */
  139. #define TEMP1_FROM_REG(val) ((val) * 1000)
  140. #define TEMP1_TO_REG(val) ((val) <= -128000 ? -128 : \
  141. (val) >= 127000 ? 127 : \
  142. (val) < 0 ? ((val) - 500) / 1000 : \
  143. ((val) + 500) / 1000)
  144. #define TEMP2_FROM_REG(val) ((val) / 32 * 125)
  145. #define TEMP2_TO_REG(val) ((val) <= -128000 ? 0x8000 : \
  146. (val) >= 127875 ? 0x7FE0 : \
  147. (val) < 0 ? ((val) - 62) / 125 * 32 : \
  148. ((val) + 62) / 125 * 32)
  149. #define HYST_TO_REG(val) ((val) <= 0 ? 0 : (val) >= 30500 ? 31 : \
  150. ((val) + 500) / 1000)
  151. /*
  152. * ADT7461 is almost identical to LM90 except that attempts to write
  153. * values that are outside the range 0 < temp < 127 are treated as
  154. * the boundary value.
  155. */
  156. #define TEMP1_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
  157. (val) >= 127000 ? 127 : \
  158. ((val) + 500) / 1000)
  159. #define TEMP2_TO_REG_ADT7461(val) ((val) <= 0 ? 0 : \
  160. (val) >= 127750 ? 0x7FC0 : \
  161. ((val) + 125) / 250 * 64)
  162. /*
  163. * Functions declaration
  164. */
  165. static int lm90_attach_adapter(struct i2c_adapter *adapter);
  166. static int lm90_detect(struct i2c_adapter *adapter, int address,
  167. int kind);
  168. static void lm90_init_client(struct i2c_client *client);
  169. static int lm90_detach_client(struct i2c_client *client);
  170. static struct lm90_data *lm90_update_device(struct device *dev);
  171. /*
  172. * Driver data (common to all clients)
  173. */
  174. static struct i2c_driver lm90_driver = {
  175. .owner = THIS_MODULE,
  176. .name = "lm90",
  177. .id = I2C_DRIVERID_LM90,
  178. .flags = I2C_DF_NOTIFY,
  179. .attach_adapter = lm90_attach_adapter,
  180. .detach_client = lm90_detach_client,
  181. };
  182. /*
  183. * Client data (each client gets its own)
  184. */
  185. struct lm90_data {
  186. struct i2c_client client;
  187. struct class_device *class_dev;
  188. struct semaphore update_lock;
  189. char valid; /* zero until following fields are valid */
  190. unsigned long last_updated; /* in jiffies */
  191. int kind;
  192. /* registers values */
  193. s8 temp8[5]; /* 0: local input
  194. 1: local low limit
  195. 2: local high limit
  196. 3: local critical limit
  197. 4: remote critical limit */
  198. s16 temp11[3]; /* 0: remote input
  199. 1: remote low limit
  200. 2: remote high limit */
  201. u8 temp_hyst;
  202. u8 alarms; /* bitvector */
  203. };
  204. /*
  205. * Sysfs stuff
  206. */
  207. static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
  208. char *buf)
  209. {
  210. struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  211. struct lm90_data *data = lm90_update_device(dev);
  212. return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index]));
  213. }
  214. static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
  215. const char *buf, size_t count)
  216. {
  217. static const u8 reg[4] = {
  218. LM90_REG_W_LOCAL_LOW,
  219. LM90_REG_W_LOCAL_HIGH,
  220. LM90_REG_W_LOCAL_CRIT,
  221. LM90_REG_W_REMOTE_CRIT,
  222. };
  223. struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  224. struct i2c_client *client = to_i2c_client(dev);
  225. struct lm90_data *data = i2c_get_clientdata(client);
  226. long val = simple_strtol(buf, NULL, 10);
  227. int nr = attr->index;
  228. down(&data->update_lock);
  229. if (data->kind == adt7461)
  230. data->temp8[nr] = TEMP1_TO_REG_ADT7461(val);
  231. else
  232. data->temp8[nr] = TEMP1_TO_REG(val);
  233. i2c_smbus_write_byte_data(client, reg[nr - 1], data->temp8[nr]);
  234. up(&data->update_lock);
  235. return count;
  236. }
  237. static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
  238. char *buf)
  239. {
  240. struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  241. struct lm90_data *data = lm90_update_device(dev);
  242. return sprintf(buf, "%d\n", TEMP2_FROM_REG(data->temp11[attr->index]));
  243. }
  244. static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
  245. const char *buf, size_t count)
  246. {
  247. static const u8 reg[4] = {
  248. LM90_REG_W_REMOTE_LOWH,
  249. LM90_REG_W_REMOTE_LOWL,
  250. LM90_REG_W_REMOTE_HIGHH,
  251. LM90_REG_W_REMOTE_HIGHL,
  252. };
  253. struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  254. struct i2c_client *client = to_i2c_client(dev);
  255. struct lm90_data *data = i2c_get_clientdata(client);
  256. long val = simple_strtol(buf, NULL, 10);
  257. int nr = attr->index;
  258. down(&data->update_lock);
  259. if (data->kind == adt7461)
  260. data->temp11[nr] = TEMP2_TO_REG_ADT7461(val);
  261. else
  262. data->temp11[nr] = TEMP2_TO_REG(val);
  263. i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
  264. data->temp11[nr] >> 8);
  265. i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
  266. data->temp11[nr] & 0xff);
  267. up(&data->update_lock);
  268. return count;
  269. }
  270. static ssize_t show_temphyst(struct device *dev, struct device_attribute *devattr,
  271. char *buf)
  272. {
  273. struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  274. struct lm90_data *data = lm90_update_device(dev);
  275. return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp8[attr->index])
  276. - TEMP1_FROM_REG(data->temp_hyst));
  277. }
  278. static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
  279. const char *buf, size_t count)
  280. {
  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. long hyst;
  285. down(&data->update_lock);
  286. hyst = TEMP1_FROM_REG(data->temp8[3]) - val;
  287. i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
  288. HYST_TO_REG(hyst));
  289. up(&data->update_lock);
  290. return count;
  291. }
  292. static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
  293. char *buf)
  294. {
  295. struct lm90_data *data = lm90_update_device(dev);
  296. return sprintf(buf, "%d\n", data->alarms);
  297. }
  298. static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp8, NULL, 0);
  299. static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp11, NULL, 0);
  300. static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
  301. set_temp8, 1);
  302. static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
  303. set_temp11, 1);
  304. static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
  305. set_temp8, 2);
  306. static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
  307. set_temp11, 2);
  308. static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
  309. set_temp8, 3);
  310. static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
  311. set_temp8, 4);
  312. static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
  313. set_temphyst, 3);
  314. static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 4);
  315. static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
  316. /*
  317. * Real code
  318. */
  319. static int lm90_attach_adapter(struct i2c_adapter *adapter)
  320. {
  321. if (!(adapter->class & I2C_CLASS_HWMON))
  322. return 0;
  323. return i2c_probe(adapter, &addr_data, lm90_detect);
  324. }
  325. /*
  326. * The following function does more than just detection. If detection
  327. * succeeds, it also registers the new chip.
  328. */
  329. static int lm90_detect(struct i2c_adapter *adapter, int address, int kind)
  330. {
  331. struct i2c_client *new_client;
  332. struct lm90_data *data;
  333. int err = 0;
  334. const char *name = "";
  335. if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
  336. goto exit;
  337. if (!(data = kmalloc(sizeof(struct lm90_data), GFP_KERNEL))) {
  338. err = -ENOMEM;
  339. goto exit;
  340. }
  341. memset(data, 0, sizeof(struct lm90_data));
  342. /* The common I2C client data is placed right before the
  343. LM90-specific data. */
  344. new_client = &data->client;
  345. i2c_set_clientdata(new_client, data);
  346. new_client->addr = address;
  347. new_client->adapter = adapter;
  348. new_client->driver = &lm90_driver;
  349. new_client->flags = 0;
  350. /*
  351. * Now we do the remaining detection. A negative kind means that
  352. * the driver was loaded with no force parameter (default), so we
  353. * must both detect and identify the chip. A zero kind means that
  354. * the driver was loaded with the force parameter, the detection
  355. * step shall be skipped. A positive kind means that the driver
  356. * was loaded with the force parameter and a given kind of chip is
  357. * requested, so both the detection and the identification steps
  358. * are skipped.
  359. */
  360. /* Default to an LM90 if forced */
  361. if (kind == 0)
  362. kind = lm90;
  363. if (kind < 0) { /* detection and identification */
  364. u8 man_id, chip_id, reg_config1, reg_convrate;
  365. man_id = i2c_smbus_read_byte_data(new_client,
  366. LM90_REG_R_MAN_ID);
  367. chip_id = i2c_smbus_read_byte_data(new_client,
  368. LM90_REG_R_CHIP_ID);
  369. reg_config1 = i2c_smbus_read_byte_data(new_client,
  370. LM90_REG_R_CONFIG1);
  371. reg_convrate = i2c_smbus_read_byte_data(new_client,
  372. LM90_REG_R_CONVRATE);
  373. if (man_id == 0x01) { /* National Semiconductor */
  374. u8 reg_config2;
  375. reg_config2 = i2c_smbus_read_byte_data(new_client,
  376. LM90_REG_R_CONFIG2);
  377. if ((reg_config1 & 0x2A) == 0x00
  378. && (reg_config2 & 0xF8) == 0x00
  379. && reg_convrate <= 0x09) {
  380. if (address == 0x4C
  381. && (chip_id & 0xF0) == 0x20) { /* LM90 */
  382. kind = lm90;
  383. } else
  384. if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
  385. kind = lm99;
  386. } else
  387. if (address == 0x4C
  388. && (chip_id & 0xF0) == 0x10) { /* LM86 */
  389. kind = lm86;
  390. }
  391. }
  392. } else
  393. if (man_id == 0x41) { /* Analog Devices */
  394. if (address == 0x4C
  395. && (chip_id & 0xF0) == 0x40 /* ADM1032 */
  396. && (reg_config1 & 0x3F) == 0x00
  397. && reg_convrate <= 0x0A) {
  398. kind = adm1032;
  399. } else
  400. if (address == 0x4c
  401. && chip_id == 0x51 /* ADT7461 */
  402. && (reg_config1 & 0x1F) == 0x00 /* check compat mode */
  403. && reg_convrate <= 0x0A) {
  404. kind = adt7461;
  405. }
  406. } else
  407. if (man_id == 0x4D) { /* Maxim */
  408. /*
  409. * The Maxim variants do NOT have a chip_id register.
  410. * Reading from that address will return the last read
  411. * value, which in our case is those of the man_id
  412. * register. Likewise, the config1 register seems to
  413. * lack a low nibble, so the value will be those of the
  414. * previous read, so in our case those of the man_id
  415. * register.
  416. */
  417. if (chip_id == man_id
  418. && (reg_config1 & 0x1F) == (man_id & 0x0F)
  419. && reg_convrate <= 0x09) {
  420. kind = max6657;
  421. }
  422. }
  423. if (kind <= 0) { /* identification failed */
  424. dev_info(&adapter->dev,
  425. "Unsupported chip (man_id=0x%02X, "
  426. "chip_id=0x%02X).\n", man_id, chip_id);
  427. goto exit_free;
  428. }
  429. }
  430. if (kind == lm90) {
  431. name = "lm90";
  432. } else if (kind == adm1032) {
  433. name = "adm1032";
  434. } else if (kind == lm99) {
  435. name = "lm99";
  436. } else if (kind == lm86) {
  437. name = "lm86";
  438. } else if (kind == max6657) {
  439. name = "max6657";
  440. } else if (kind == adt7461) {
  441. name = "adt7461";
  442. }
  443. /* We can fill in the remaining client fields */
  444. strlcpy(new_client->name, name, I2C_NAME_SIZE);
  445. data->valid = 0;
  446. data->kind = kind;
  447. init_MUTEX(&data->update_lock);
  448. /* Tell the I2C layer a new client has arrived */
  449. if ((err = i2c_attach_client(new_client)))
  450. goto exit_free;
  451. /* Initialize the LM90 chip */
  452. lm90_init_client(new_client);
  453. /* Register sysfs hooks */
  454. data->class_dev = hwmon_device_register(&new_client->dev);
  455. if (IS_ERR(data->class_dev)) {
  456. err = PTR_ERR(data->class_dev);
  457. goto exit_detach;
  458. }
  459. device_create_file(&new_client->dev,
  460. &sensor_dev_attr_temp1_input.dev_attr);
  461. device_create_file(&new_client->dev,
  462. &sensor_dev_attr_temp2_input.dev_attr);
  463. device_create_file(&new_client->dev,
  464. &sensor_dev_attr_temp1_min.dev_attr);
  465. device_create_file(&new_client->dev,
  466. &sensor_dev_attr_temp2_min.dev_attr);
  467. device_create_file(&new_client->dev,
  468. &sensor_dev_attr_temp1_max.dev_attr);
  469. device_create_file(&new_client->dev,
  470. &sensor_dev_attr_temp2_max.dev_attr);
  471. device_create_file(&new_client->dev,
  472. &sensor_dev_attr_temp1_crit.dev_attr);
  473. device_create_file(&new_client->dev,
  474. &sensor_dev_attr_temp2_crit.dev_attr);
  475. device_create_file(&new_client->dev,
  476. &sensor_dev_attr_temp1_crit_hyst.dev_attr);
  477. device_create_file(&new_client->dev,
  478. &sensor_dev_attr_temp2_crit_hyst.dev_attr);
  479. device_create_file(&new_client->dev, &dev_attr_alarms);
  480. return 0;
  481. exit_detach:
  482. i2c_detach_client(new_client);
  483. exit_free:
  484. kfree(data);
  485. exit:
  486. return err;
  487. }
  488. static void lm90_init_client(struct i2c_client *client)
  489. {
  490. u8 config;
  491. /*
  492. * Start the conversions.
  493. */
  494. i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
  495. 5); /* 2 Hz */
  496. config = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG1);
  497. if (config & 0x40)
  498. i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
  499. config & 0xBF); /* run */
  500. }
  501. static int lm90_detach_client(struct i2c_client *client)
  502. {
  503. struct lm90_data *data = i2c_get_clientdata(client);
  504. int err;
  505. hwmon_device_unregister(data->class_dev);
  506. if ((err = i2c_detach_client(client)))
  507. return err;
  508. kfree(data);
  509. return 0;
  510. }
  511. static struct lm90_data *lm90_update_device(struct device *dev)
  512. {
  513. struct i2c_client *client = to_i2c_client(dev);
  514. struct lm90_data *data = i2c_get_clientdata(client);
  515. down(&data->update_lock);
  516. if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
  517. u8 oldh, newh;
  518. dev_dbg(&client->dev, "Updating lm90 data.\n");
  519. data->temp8[0] = i2c_smbus_read_byte_data(client,
  520. LM90_REG_R_LOCAL_TEMP);
  521. data->temp8[1] = i2c_smbus_read_byte_data(client,
  522. LM90_REG_R_LOCAL_LOW);
  523. data->temp8[2] = i2c_smbus_read_byte_data(client,
  524. LM90_REG_R_LOCAL_HIGH);
  525. data->temp8[3] = i2c_smbus_read_byte_data(client,
  526. LM90_REG_R_LOCAL_CRIT);
  527. data->temp8[4] = i2c_smbus_read_byte_data(client,
  528. LM90_REG_R_REMOTE_CRIT);
  529. data->temp_hyst = i2c_smbus_read_byte_data(client,
  530. LM90_REG_R_TCRIT_HYST);
  531. /*
  532. * There is a trick here. We have to read two registers to
  533. * have the remote sensor temperature, but we have to beware
  534. * a conversion could occur inbetween the readings. The
  535. * datasheet says we should either use the one-shot
  536. * conversion register, which we don't want to do (disables
  537. * hardware monitoring) or monitor the busy bit, which is
  538. * impossible (we can't read the values and monitor that bit
  539. * at the exact same time). So the solution used here is to
  540. * read the high byte once, then the low byte, then the high
  541. * byte again. If the new high byte matches the old one,
  542. * then we have a valid reading. Else we have to read the low
  543. * byte again, and now we believe we have a correct reading.
  544. */
  545. oldh = i2c_smbus_read_byte_data(client,
  546. LM90_REG_R_REMOTE_TEMPH);
  547. data->temp11[0] = i2c_smbus_read_byte_data(client,
  548. LM90_REG_R_REMOTE_TEMPL);
  549. newh = i2c_smbus_read_byte_data(client,
  550. LM90_REG_R_REMOTE_TEMPH);
  551. if (newh != oldh) {
  552. data->temp11[0] = i2c_smbus_read_byte_data(client,
  553. LM90_REG_R_REMOTE_TEMPL);
  554. #ifdef DEBUG
  555. oldh = i2c_smbus_read_byte_data(client,
  556. LM90_REG_R_REMOTE_TEMPH);
  557. /* oldh is actually newer */
  558. if (newh != oldh)
  559. dev_warn(&client->dev, "Remote temperature may be "
  560. "wrong.\n");
  561. #endif
  562. }
  563. data->temp11[0] |= (newh << 8);
  564. data->temp11[1] = (i2c_smbus_read_byte_data(client,
  565. LM90_REG_R_REMOTE_LOWH) << 8) +
  566. i2c_smbus_read_byte_data(client,
  567. LM90_REG_R_REMOTE_LOWL);
  568. data->temp11[2] = (i2c_smbus_read_byte_data(client,
  569. LM90_REG_R_REMOTE_HIGHH) << 8) +
  570. i2c_smbus_read_byte_data(client,
  571. LM90_REG_R_REMOTE_HIGHL);
  572. data->alarms = i2c_smbus_read_byte_data(client,
  573. LM90_REG_R_STATUS);
  574. data->last_updated = jiffies;
  575. data->valid = 1;
  576. }
  577. up(&data->update_lock);
  578. return data;
  579. }
  580. static int __init sensors_lm90_init(void)
  581. {
  582. return i2c_add_driver(&lm90_driver);
  583. }
  584. static void __exit sensors_lm90_exit(void)
  585. {
  586. i2c_del_driver(&lm90_driver);
  587. }
  588. MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
  589. MODULE_DESCRIPTION("LM90/ADM1032 driver");
  590. MODULE_LICENSE("GPL");
  591. module_init(sensors_lm90_init);
  592. module_exit(sensors_lm90_exit);