w83773g.c 6.8 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * Copyright (C) 2017 IBM Corp.
  4. *
  5. * Driver for the Nuvoton W83773G SMBus temperature sensor IC.
  6. * Supported models: W83773G
  7. */
  8. #include <linux/module.h>
  9. #include <linux/init.h>
  10. #include <linux/i2c.h>
  11. #include <linux/hwmon.h>
  12. #include <linux/hwmon-sysfs.h>
  13. #include <linux/err.h>
  14. #include <linux/of_device.h>
  15. #include <linux/regmap.h>
  16. /* W83773 has 3 channels */
  17. #define W83773_CHANNELS 3
  18. /* The W83773 registers */
  19. #define W83773_CONVERSION_RATE_REG_READ 0x04
  20. #define W83773_CONVERSION_RATE_REG_WRITE 0x0A
  21. #define W83773_MANUFACTURER_ID_REG 0xFE
  22. #define W83773_LOCAL_TEMP 0x00
  23. static const u8 W83773_STATUS[2] = { 0x02, 0x17 };
  24. static const u8 W83773_TEMP_LSB[2] = { 0x10, 0x25 };
  25. static const u8 W83773_TEMP_MSB[2] = { 0x01, 0x24 };
  26. static const u8 W83773_OFFSET_LSB[2] = { 0x12, 0x16 };
  27. static const u8 W83773_OFFSET_MSB[2] = { 0x11, 0x15 };
  28. /* this is the number of sensors in the device */
  29. static const struct i2c_device_id w83773_id[] = {
  30. { "w83773g" },
  31. { }
  32. };
  33. MODULE_DEVICE_TABLE(i2c, w83773_id);
  34. static const struct of_device_id __maybe_unused w83773_of_match[] = {
  35. {
  36. .compatible = "nuvoton,w83773g"
  37. },
  38. { },
  39. };
  40. MODULE_DEVICE_TABLE(of, w83773_of_match);
  41. static inline long temp_of_local(s8 reg)
  42. {
  43. return reg * 1000;
  44. }
  45. static inline long temp_of_remote(s8 hb, u8 lb)
  46. {
  47. return (hb << 3 | lb >> 5) * 125;
  48. }
  49. static int get_local_temp(struct regmap *regmap, long *val)
  50. {
  51. unsigned int regval;
  52. int ret;
  53. ret = regmap_read(regmap, W83773_LOCAL_TEMP, &regval);
  54. if (ret < 0)
  55. return ret;
  56. *val = temp_of_local(regval);
  57. return 0;
  58. }
  59. static int get_remote_temp(struct regmap *regmap, int index, long *val)
  60. {
  61. unsigned int regval_high;
  62. unsigned int regval_low;
  63. int ret;
  64. ret = regmap_read(regmap, W83773_TEMP_MSB[index], &regval_high);
  65. if (ret < 0)
  66. return ret;
  67. ret = regmap_read(regmap, W83773_TEMP_LSB[index], &regval_low);
  68. if (ret < 0)
  69. return ret;
  70. *val = temp_of_remote(regval_high, regval_low);
  71. return 0;
  72. }
  73. static int get_fault(struct regmap *regmap, int index, long *val)
  74. {
  75. unsigned int regval;
  76. int ret;
  77. ret = regmap_read(regmap, W83773_STATUS[index], &regval);
  78. if (ret < 0)
  79. return ret;
  80. *val = (regval & 0x04) >> 2;
  81. return 0;
  82. }
  83. static int get_offset(struct regmap *regmap, int index, long *val)
  84. {
  85. unsigned int regval_high;
  86. unsigned int regval_low;
  87. int ret;
  88. ret = regmap_read(regmap, W83773_OFFSET_MSB[index], &regval_high);
  89. if (ret < 0)
  90. return ret;
  91. ret = regmap_read(regmap, W83773_OFFSET_LSB[index], &regval_low);
  92. if (ret < 0)
  93. return ret;
  94. *val = temp_of_remote(regval_high, regval_low);
  95. return 0;
  96. }
  97. static int set_offset(struct regmap *regmap, int index, long val)
  98. {
  99. int ret;
  100. u8 high_byte;
  101. u8 low_byte;
  102. val = clamp_val(val, -127825, 127825);
  103. /* offset value equals to (high_byte << 3 | low_byte >> 5) * 125 */
  104. val /= 125;
  105. high_byte = val >> 3;
  106. low_byte = (val & 0x07) << 5;
  107. ret = regmap_write(regmap, W83773_OFFSET_MSB[index], high_byte);
  108. if (ret < 0)
  109. return ret;
  110. return regmap_write(regmap, W83773_OFFSET_LSB[index], low_byte);
  111. }
  112. static int get_update_interval(struct regmap *regmap, long *val)
  113. {
  114. unsigned int regval;
  115. int ret;
  116. ret = regmap_read(regmap, W83773_CONVERSION_RATE_REG_READ, &regval);
  117. if (ret < 0)
  118. return ret;
  119. *val = 16000 >> regval;
  120. return 0;
  121. }
  122. static int set_update_interval(struct regmap *regmap, long val)
  123. {
  124. int rate;
  125. /*
  126. * For valid rates, interval can be calculated as
  127. * interval = (1 << (8 - rate)) * 62.5;
  128. * Rounded rate is therefore
  129. * rate = 8 - __fls(interval * 8 / (62.5 * 7));
  130. * Use clamp_val() to avoid overflows, and to ensure valid input
  131. * for __fls.
  132. */
  133. val = clamp_val(val, 62, 16000) * 10;
  134. rate = 8 - __fls((val * 8 / (625 * 7)));
  135. return regmap_write(regmap, W83773_CONVERSION_RATE_REG_WRITE, rate);
  136. }
  137. static int w83773_read(struct device *dev, enum hwmon_sensor_types type,
  138. u32 attr, int channel, long *val)
  139. {
  140. struct regmap *regmap = dev_get_drvdata(dev);
  141. if (type == hwmon_chip) {
  142. if (attr == hwmon_chip_update_interval)
  143. return get_update_interval(regmap, val);
  144. return -EOPNOTSUPP;
  145. }
  146. switch (attr) {
  147. case hwmon_temp_input:
  148. if (channel == 0)
  149. return get_local_temp(regmap, val);
  150. return get_remote_temp(regmap, channel - 1, val);
  151. case hwmon_temp_fault:
  152. return get_fault(regmap, channel - 1, val);
  153. case hwmon_temp_offset:
  154. return get_offset(regmap, channel - 1, val);
  155. default:
  156. return -EOPNOTSUPP;
  157. }
  158. }
  159. static int w83773_write(struct device *dev, enum hwmon_sensor_types type,
  160. u32 attr, int channel, long val)
  161. {
  162. struct regmap *regmap = dev_get_drvdata(dev);
  163. if (type == hwmon_chip && attr == hwmon_chip_update_interval)
  164. return set_update_interval(regmap, val);
  165. if (type == hwmon_temp && attr == hwmon_temp_offset)
  166. return set_offset(regmap, channel - 1, val);
  167. return -EOPNOTSUPP;
  168. }
  169. static umode_t w83773_is_visible(const void *data, enum hwmon_sensor_types type,
  170. u32 attr, int channel)
  171. {
  172. switch (type) {
  173. case hwmon_chip:
  174. switch (attr) {
  175. case hwmon_chip_update_interval:
  176. return 0644;
  177. }
  178. break;
  179. case hwmon_temp:
  180. switch (attr) {
  181. case hwmon_temp_input:
  182. case hwmon_temp_fault:
  183. return 0444;
  184. case hwmon_temp_offset:
  185. return 0644;
  186. }
  187. break;
  188. default:
  189. break;
  190. }
  191. return 0;
  192. }
  193. static const struct hwmon_channel_info *w83773_info[] = {
  194. HWMON_CHANNEL_INFO(chip,
  195. HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
  196. HWMON_CHANNEL_INFO(temp,
  197. HWMON_T_INPUT,
  198. HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_OFFSET,
  199. HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_OFFSET),
  200. NULL
  201. };
  202. static const struct hwmon_ops w83773_ops = {
  203. .is_visible = w83773_is_visible,
  204. .read = w83773_read,
  205. .write = w83773_write,
  206. };
  207. static const struct hwmon_chip_info w83773_chip_info = {
  208. .ops = &w83773_ops,
  209. .info = w83773_info,
  210. };
  211. static const struct regmap_config w83773_regmap_config = {
  212. .reg_bits = 8,
  213. .val_bits = 8,
  214. };
  215. static int w83773_probe(struct i2c_client *client)
  216. {
  217. struct device *dev = &client->dev;
  218. struct device *hwmon_dev;
  219. struct regmap *regmap;
  220. int ret;
  221. regmap = devm_regmap_init_i2c(client, &w83773_regmap_config);
  222. if (IS_ERR(regmap)) {
  223. dev_err(dev, "failed to allocate register map\n");
  224. return PTR_ERR(regmap);
  225. }
  226. /* Set the conversion rate to 2 Hz */
  227. ret = regmap_write(regmap, W83773_CONVERSION_RATE_REG_WRITE, 0x05);
  228. if (ret < 0) {
  229. dev_err(&client->dev, "error writing config rate register\n");
  230. return ret;
  231. }
  232. i2c_set_clientdata(client, regmap);
  233. hwmon_dev = devm_hwmon_device_register_with_info(dev,
  234. client->name,
  235. regmap,
  236. &w83773_chip_info,
  237. NULL);
  238. return PTR_ERR_OR_ZERO(hwmon_dev);
  239. }
  240. static struct i2c_driver w83773_driver = {
  241. .class = I2C_CLASS_HWMON,
  242. .driver = {
  243. .name = "w83773g",
  244. .of_match_table = of_match_ptr(w83773_of_match),
  245. },
  246. .probe_new = w83773_probe,
  247. .id_table = w83773_id,
  248. };
  249. module_i2c_driver(w83773_driver);
  250. MODULE_AUTHOR("Lei YU <[email protected]>");
  251. MODULE_DESCRIPTION("W83773G temperature sensor driver");
  252. MODULE_LICENSE("GPL");