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