ltc2945.c 14 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * Driver for Linear Technology LTC2945 I2C Power Monitor
  4. *
  5. * Copyright (c) 2014 Guenter Roeck
  6. */
  7. #include <linux/kernel.h>
  8. #include <linux/module.h>
  9. #include <linux/err.h>
  10. #include <linux/slab.h>
  11. #include <linux/i2c.h>
  12. #include <linux/hwmon.h>
  13. #include <linux/hwmon-sysfs.h>
  14. #include <linux/jiffies.h>
  15. #include <linux/regmap.h>
  16. /* chip registers */
  17. #define LTC2945_CONTROL 0x00
  18. #define LTC2945_ALERT 0x01
  19. #define LTC2945_STATUS 0x02
  20. #define LTC2945_FAULT 0x03
  21. #define LTC2945_POWER_H 0x05
  22. #define LTC2945_MAX_POWER_H 0x08
  23. #define LTC2945_MIN_POWER_H 0x0b
  24. #define LTC2945_MAX_POWER_THRES_H 0x0e
  25. #define LTC2945_MIN_POWER_THRES_H 0x11
  26. #define LTC2945_SENSE_H 0x14
  27. #define LTC2945_MAX_SENSE_H 0x16
  28. #define LTC2945_MIN_SENSE_H 0x18
  29. #define LTC2945_MAX_SENSE_THRES_H 0x1a
  30. #define LTC2945_MIN_SENSE_THRES_H 0x1c
  31. #define LTC2945_VIN_H 0x1e
  32. #define LTC2945_MAX_VIN_H 0x20
  33. #define LTC2945_MIN_VIN_H 0x22
  34. #define LTC2945_MAX_VIN_THRES_H 0x24
  35. #define LTC2945_MIN_VIN_THRES_H 0x26
  36. #define LTC2945_ADIN_H 0x28
  37. #define LTC2945_MAX_ADIN_H 0x2a
  38. #define LTC2945_MIN_ADIN_H 0x2c
  39. #define LTC2945_MAX_ADIN_THRES_H 0x2e
  40. #define LTC2945_MIN_ADIN_THRES_H 0x30
  41. #define LTC2945_MIN_ADIN_THRES_L 0x31
  42. /* Fault register bits */
  43. #define FAULT_ADIN_UV (1 << 0)
  44. #define FAULT_ADIN_OV (1 << 1)
  45. #define FAULT_VIN_UV (1 << 2)
  46. #define FAULT_VIN_OV (1 << 3)
  47. #define FAULT_SENSE_UV (1 << 4)
  48. #define FAULT_SENSE_OV (1 << 5)
  49. #define FAULT_POWER_UV (1 << 6)
  50. #define FAULT_POWER_OV (1 << 7)
  51. /* Control register bits */
  52. #define CONTROL_MULT_SELECT (1 << 0)
  53. #define CONTROL_TEST_MODE (1 << 4)
  54. static inline bool is_power_reg(u8 reg)
  55. {
  56. return reg < LTC2945_SENSE_H;
  57. }
  58. /* Return the value from the given register in uW, mV, or mA */
  59. static long long ltc2945_reg_to_val(struct device *dev, u8 reg)
  60. {
  61. struct regmap *regmap = dev_get_drvdata(dev);
  62. unsigned int control;
  63. u8 buf[3];
  64. long long val;
  65. int ret;
  66. ret = regmap_bulk_read(regmap, reg, buf,
  67. is_power_reg(reg) ? 3 : 2);
  68. if (ret < 0)
  69. return ret;
  70. if (is_power_reg(reg)) {
  71. /* power */
  72. val = (buf[0] << 16) + (buf[1] << 8) + buf[2];
  73. } else {
  74. /* current, voltage */
  75. val = (buf[0] << 4) + (buf[1] >> 4);
  76. }
  77. switch (reg) {
  78. case LTC2945_POWER_H:
  79. case LTC2945_MAX_POWER_H:
  80. case LTC2945_MIN_POWER_H:
  81. case LTC2945_MAX_POWER_THRES_H:
  82. case LTC2945_MIN_POWER_THRES_H:
  83. /*
  84. * Convert to uW by assuming current is measured with
  85. * an 1mOhm sense resistor, similar to current
  86. * measurements.
  87. * Control register bit 0 selects if voltage at SENSE+/VDD
  88. * or voltage at ADIN is used to measure power.
  89. */
  90. ret = regmap_read(regmap, LTC2945_CONTROL, &control);
  91. if (ret < 0)
  92. return ret;
  93. if (control & CONTROL_MULT_SELECT) {
  94. /* 25 mV * 25 uV = 0.625 uV resolution. */
  95. val *= 625LL;
  96. } else {
  97. /* 0.5 mV * 25 uV = 0.0125 uV resolution. */
  98. val = (val * 25LL) >> 1;
  99. }
  100. break;
  101. case LTC2945_VIN_H:
  102. case LTC2945_MAX_VIN_H:
  103. case LTC2945_MIN_VIN_H:
  104. case LTC2945_MAX_VIN_THRES_H:
  105. case LTC2945_MIN_VIN_THRES_H:
  106. /* 25 mV resolution. Convert to mV. */
  107. val *= 25;
  108. break;
  109. case LTC2945_ADIN_H:
  110. case LTC2945_MAX_ADIN_H:
  111. case LTC2945_MIN_ADIN_THRES_H:
  112. case LTC2945_MAX_ADIN_THRES_H:
  113. case LTC2945_MIN_ADIN_H:
  114. /* 0.5mV resolution. Convert to mV. */
  115. val = val >> 1;
  116. break;
  117. case LTC2945_SENSE_H:
  118. case LTC2945_MAX_SENSE_H:
  119. case LTC2945_MIN_SENSE_H:
  120. case LTC2945_MAX_SENSE_THRES_H:
  121. case LTC2945_MIN_SENSE_THRES_H:
  122. /*
  123. * 25 uV resolution. Convert to current as measured with
  124. * an 1 mOhm sense resistor, in mA. If a different sense
  125. * resistor is installed, calculate the actual current by
  126. * dividing the reported current by the sense resistor value
  127. * in mOhm.
  128. */
  129. val *= 25;
  130. break;
  131. default:
  132. return -EINVAL;
  133. }
  134. return val;
  135. }
  136. static int ltc2945_val_to_reg(struct device *dev, u8 reg,
  137. unsigned long val)
  138. {
  139. struct regmap *regmap = dev_get_drvdata(dev);
  140. unsigned int control;
  141. int ret;
  142. switch (reg) {
  143. case LTC2945_POWER_H:
  144. case LTC2945_MAX_POWER_H:
  145. case LTC2945_MIN_POWER_H:
  146. case LTC2945_MAX_POWER_THRES_H:
  147. case LTC2945_MIN_POWER_THRES_H:
  148. /*
  149. * Convert to register value by assuming current is measured
  150. * with an 1mOhm sense resistor, similar to current
  151. * measurements.
  152. * Control register bit 0 selects if voltage at SENSE+/VDD
  153. * or voltage at ADIN is used to measure power, which in turn
  154. * determines register calculations.
  155. */
  156. ret = regmap_read(regmap, LTC2945_CONTROL, &control);
  157. if (ret < 0)
  158. return ret;
  159. if (control & CONTROL_MULT_SELECT) {
  160. /* 25 mV * 25 uV = 0.625 uV resolution. */
  161. val = DIV_ROUND_CLOSEST(val, 625);
  162. } else {
  163. /*
  164. * 0.5 mV * 25 uV = 0.0125 uV resolution.
  165. * Divide first to avoid overflow;
  166. * accept loss of accuracy.
  167. */
  168. val = DIV_ROUND_CLOSEST(val, 25) * 2;
  169. }
  170. break;
  171. case LTC2945_VIN_H:
  172. case LTC2945_MAX_VIN_H:
  173. case LTC2945_MIN_VIN_H:
  174. case LTC2945_MAX_VIN_THRES_H:
  175. case LTC2945_MIN_VIN_THRES_H:
  176. /* 25 mV resolution. */
  177. val /= 25;
  178. break;
  179. case LTC2945_ADIN_H:
  180. case LTC2945_MAX_ADIN_H:
  181. case LTC2945_MIN_ADIN_THRES_H:
  182. case LTC2945_MAX_ADIN_THRES_H:
  183. case LTC2945_MIN_ADIN_H:
  184. /* 0.5mV resolution. */
  185. val *= 2;
  186. break;
  187. case LTC2945_SENSE_H:
  188. case LTC2945_MAX_SENSE_H:
  189. case LTC2945_MIN_SENSE_H:
  190. case LTC2945_MAX_SENSE_THRES_H:
  191. case LTC2945_MIN_SENSE_THRES_H:
  192. /*
  193. * 25 uV resolution. Convert to current as measured with
  194. * an 1 mOhm sense resistor, in mA. If a different sense
  195. * resistor is installed, calculate the actual current by
  196. * dividing the reported current by the sense resistor value
  197. * in mOhm.
  198. */
  199. val = DIV_ROUND_CLOSEST(val, 25);
  200. break;
  201. default:
  202. return -EINVAL;
  203. }
  204. return val;
  205. }
  206. static ssize_t ltc2945_value_show(struct device *dev,
  207. struct device_attribute *da, char *buf)
  208. {
  209. struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
  210. long long value;
  211. value = ltc2945_reg_to_val(dev, attr->index);
  212. if (value < 0)
  213. return value;
  214. return snprintf(buf, PAGE_SIZE, "%lld\n", value);
  215. }
  216. static ssize_t ltc2945_value_store(struct device *dev,
  217. struct device_attribute *da,
  218. const char *buf, size_t count)
  219. {
  220. struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
  221. struct regmap *regmap = dev_get_drvdata(dev);
  222. u8 reg = attr->index;
  223. unsigned long val;
  224. u8 regbuf[3];
  225. int num_regs;
  226. int regval;
  227. int ret;
  228. ret = kstrtoul(buf, 10, &val);
  229. if (ret)
  230. return ret;
  231. /* convert to register value, then clamp and write result */
  232. regval = ltc2945_val_to_reg(dev, reg, val);
  233. if (is_power_reg(reg)) {
  234. regval = clamp_val(regval, 0, 0xffffff);
  235. regbuf[0] = regval >> 16;
  236. regbuf[1] = (regval >> 8) & 0xff;
  237. regbuf[2] = regval;
  238. num_regs = 3;
  239. } else {
  240. regval = clamp_val(regval, 0, 0xfff) << 4;
  241. regbuf[0] = regval >> 8;
  242. regbuf[1] = regval & 0xff;
  243. num_regs = 2;
  244. }
  245. ret = regmap_bulk_write(regmap, reg, regbuf, num_regs);
  246. return ret < 0 ? ret : count;
  247. }
  248. static ssize_t ltc2945_history_store(struct device *dev,
  249. struct device_attribute *da,
  250. const char *buf, size_t count)
  251. {
  252. struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
  253. struct regmap *regmap = dev_get_drvdata(dev);
  254. u8 reg = attr->index;
  255. int num_regs = is_power_reg(reg) ? 3 : 2;
  256. u8 buf_min[3] = { 0xff, 0xff, 0xff };
  257. u8 buf_max[3] = { 0, 0, 0 };
  258. unsigned long val;
  259. int ret;
  260. ret = kstrtoul(buf, 10, &val);
  261. if (ret)
  262. return ret;
  263. if (val != 1)
  264. return -EINVAL;
  265. ret = regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE,
  266. CONTROL_TEST_MODE);
  267. /* Reset minimum */
  268. ret = regmap_bulk_write(regmap, reg, buf_min, num_regs);
  269. if (ret)
  270. return ret;
  271. switch (reg) {
  272. case LTC2945_MIN_POWER_H:
  273. reg = LTC2945_MAX_POWER_H;
  274. break;
  275. case LTC2945_MIN_SENSE_H:
  276. reg = LTC2945_MAX_SENSE_H;
  277. break;
  278. case LTC2945_MIN_VIN_H:
  279. reg = LTC2945_MAX_VIN_H;
  280. break;
  281. case LTC2945_MIN_ADIN_H:
  282. reg = LTC2945_MAX_ADIN_H;
  283. break;
  284. default:
  285. WARN_ONCE(1, "Bad register: 0x%x\n", reg);
  286. return -EINVAL;
  287. }
  288. /* Reset maximum */
  289. ret = regmap_bulk_write(regmap, reg, buf_max, num_regs);
  290. /* Try resetting test mode even if there was an error */
  291. regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE, 0);
  292. return ret ? : count;
  293. }
  294. static ssize_t ltc2945_bool_show(struct device *dev,
  295. struct device_attribute *da, char *buf)
  296. {
  297. struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
  298. struct regmap *regmap = dev_get_drvdata(dev);
  299. unsigned int fault;
  300. int ret;
  301. ret = regmap_read(regmap, LTC2945_FAULT, &fault);
  302. if (ret < 0)
  303. return ret;
  304. fault &= attr->index;
  305. if (fault) /* Clear reported faults in chip register */
  306. regmap_update_bits(regmap, LTC2945_FAULT, attr->index, 0);
  307. return snprintf(buf, PAGE_SIZE, "%d\n", !!fault);
  308. }
  309. /* Input voltages */
  310. static SENSOR_DEVICE_ATTR_RO(in1_input, ltc2945_value, LTC2945_VIN_H);
  311. static SENSOR_DEVICE_ATTR_RW(in1_min, ltc2945_value, LTC2945_MIN_VIN_THRES_H);
  312. static SENSOR_DEVICE_ATTR_RW(in1_max, ltc2945_value, LTC2945_MAX_VIN_THRES_H);
  313. static SENSOR_DEVICE_ATTR_RO(in1_lowest, ltc2945_value, LTC2945_MIN_VIN_H);
  314. static SENSOR_DEVICE_ATTR_RO(in1_highest, ltc2945_value, LTC2945_MAX_VIN_H);
  315. static SENSOR_DEVICE_ATTR_WO(in1_reset_history, ltc2945_history,
  316. LTC2945_MIN_VIN_H);
  317. static SENSOR_DEVICE_ATTR_RO(in2_input, ltc2945_value, LTC2945_ADIN_H);
  318. static SENSOR_DEVICE_ATTR_RW(in2_min, ltc2945_value, LTC2945_MIN_ADIN_THRES_H);
  319. static SENSOR_DEVICE_ATTR_RW(in2_max, ltc2945_value, LTC2945_MAX_ADIN_THRES_H);
  320. static SENSOR_DEVICE_ATTR_RO(in2_lowest, ltc2945_value, LTC2945_MIN_ADIN_H);
  321. static SENSOR_DEVICE_ATTR_RO(in2_highest, ltc2945_value, LTC2945_MAX_ADIN_H);
  322. static SENSOR_DEVICE_ATTR_WO(in2_reset_history, ltc2945_history,
  323. LTC2945_MIN_ADIN_H);
  324. /* Voltage alarms */
  325. static SENSOR_DEVICE_ATTR_RO(in1_min_alarm, ltc2945_bool, FAULT_VIN_UV);
  326. static SENSOR_DEVICE_ATTR_RO(in1_max_alarm, ltc2945_bool, FAULT_VIN_OV);
  327. static SENSOR_DEVICE_ATTR_RO(in2_min_alarm, ltc2945_bool, FAULT_ADIN_UV);
  328. static SENSOR_DEVICE_ATTR_RO(in2_max_alarm, ltc2945_bool, FAULT_ADIN_OV);
  329. /* Currents (via sense resistor) */
  330. static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc2945_value, LTC2945_SENSE_H);
  331. static SENSOR_DEVICE_ATTR_RW(curr1_min, ltc2945_value,
  332. LTC2945_MIN_SENSE_THRES_H);
  333. static SENSOR_DEVICE_ATTR_RW(curr1_max, ltc2945_value,
  334. LTC2945_MAX_SENSE_THRES_H);
  335. static SENSOR_DEVICE_ATTR_RO(curr1_lowest, ltc2945_value, LTC2945_MIN_SENSE_H);
  336. static SENSOR_DEVICE_ATTR_RO(curr1_highest, ltc2945_value,
  337. LTC2945_MAX_SENSE_H);
  338. static SENSOR_DEVICE_ATTR_WO(curr1_reset_history, ltc2945_history,
  339. LTC2945_MIN_SENSE_H);
  340. /* Current alarms */
  341. static SENSOR_DEVICE_ATTR_RO(curr1_min_alarm, ltc2945_bool, FAULT_SENSE_UV);
  342. static SENSOR_DEVICE_ATTR_RO(curr1_max_alarm, ltc2945_bool, FAULT_SENSE_OV);
  343. /* Power */
  344. static SENSOR_DEVICE_ATTR_RO(power1_input, ltc2945_value, LTC2945_POWER_H);
  345. static SENSOR_DEVICE_ATTR_RW(power1_min, ltc2945_value,
  346. LTC2945_MIN_POWER_THRES_H);
  347. static SENSOR_DEVICE_ATTR_RW(power1_max, ltc2945_value,
  348. LTC2945_MAX_POWER_THRES_H);
  349. static SENSOR_DEVICE_ATTR_RO(power1_input_lowest, ltc2945_value,
  350. LTC2945_MIN_POWER_H);
  351. static SENSOR_DEVICE_ATTR_RO(power1_input_highest, ltc2945_value,
  352. LTC2945_MAX_POWER_H);
  353. static SENSOR_DEVICE_ATTR_WO(power1_reset_history, ltc2945_history,
  354. LTC2945_MIN_POWER_H);
  355. /* Power alarms */
  356. static SENSOR_DEVICE_ATTR_RO(power1_min_alarm, ltc2945_bool, FAULT_POWER_UV);
  357. static SENSOR_DEVICE_ATTR_RO(power1_max_alarm, ltc2945_bool, FAULT_POWER_OV);
  358. static struct attribute *ltc2945_attrs[] = {
  359. &sensor_dev_attr_in1_input.dev_attr.attr,
  360. &sensor_dev_attr_in1_min.dev_attr.attr,
  361. &sensor_dev_attr_in1_max.dev_attr.attr,
  362. &sensor_dev_attr_in1_lowest.dev_attr.attr,
  363. &sensor_dev_attr_in1_highest.dev_attr.attr,
  364. &sensor_dev_attr_in1_reset_history.dev_attr.attr,
  365. &sensor_dev_attr_in1_min_alarm.dev_attr.attr,
  366. &sensor_dev_attr_in1_max_alarm.dev_attr.attr,
  367. &sensor_dev_attr_in2_input.dev_attr.attr,
  368. &sensor_dev_attr_in2_min.dev_attr.attr,
  369. &sensor_dev_attr_in2_max.dev_attr.attr,
  370. &sensor_dev_attr_in2_lowest.dev_attr.attr,
  371. &sensor_dev_attr_in2_highest.dev_attr.attr,
  372. &sensor_dev_attr_in2_reset_history.dev_attr.attr,
  373. &sensor_dev_attr_in2_min_alarm.dev_attr.attr,
  374. &sensor_dev_attr_in2_max_alarm.dev_attr.attr,
  375. &sensor_dev_attr_curr1_input.dev_attr.attr,
  376. &sensor_dev_attr_curr1_min.dev_attr.attr,
  377. &sensor_dev_attr_curr1_max.dev_attr.attr,
  378. &sensor_dev_attr_curr1_lowest.dev_attr.attr,
  379. &sensor_dev_attr_curr1_highest.dev_attr.attr,
  380. &sensor_dev_attr_curr1_reset_history.dev_attr.attr,
  381. &sensor_dev_attr_curr1_min_alarm.dev_attr.attr,
  382. &sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
  383. &sensor_dev_attr_power1_input.dev_attr.attr,
  384. &sensor_dev_attr_power1_min.dev_attr.attr,
  385. &sensor_dev_attr_power1_max.dev_attr.attr,
  386. &sensor_dev_attr_power1_input_lowest.dev_attr.attr,
  387. &sensor_dev_attr_power1_input_highest.dev_attr.attr,
  388. &sensor_dev_attr_power1_reset_history.dev_attr.attr,
  389. &sensor_dev_attr_power1_min_alarm.dev_attr.attr,
  390. &sensor_dev_attr_power1_max_alarm.dev_attr.attr,
  391. NULL,
  392. };
  393. ATTRIBUTE_GROUPS(ltc2945);
  394. static const struct regmap_config ltc2945_regmap_config = {
  395. .reg_bits = 8,
  396. .val_bits = 8,
  397. .max_register = LTC2945_MIN_ADIN_THRES_L,
  398. };
  399. static int ltc2945_probe(struct i2c_client *client)
  400. {
  401. struct device *dev = &client->dev;
  402. struct device *hwmon_dev;
  403. struct regmap *regmap;
  404. regmap = devm_regmap_init_i2c(client, &ltc2945_regmap_config);
  405. if (IS_ERR(regmap)) {
  406. dev_err(dev, "failed to allocate register map\n");
  407. return PTR_ERR(regmap);
  408. }
  409. /* Clear faults */
  410. regmap_write(regmap, LTC2945_FAULT, 0x00);
  411. hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
  412. regmap,
  413. ltc2945_groups);
  414. return PTR_ERR_OR_ZERO(hwmon_dev);
  415. }
  416. static const struct i2c_device_id ltc2945_id[] = {
  417. {"ltc2945", 0},
  418. { }
  419. };
  420. MODULE_DEVICE_TABLE(i2c, ltc2945_id);
  421. static struct i2c_driver ltc2945_driver = {
  422. .driver = {
  423. .name = "ltc2945",
  424. },
  425. .probe_new = ltc2945_probe,
  426. .id_table = ltc2945_id,
  427. };
  428. module_i2c_driver(ltc2945_driver);
  429. MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
  430. MODULE_DESCRIPTION("LTC2945 driver");
  431. MODULE_LICENSE("GPL");