leds-an30259a.c 8.6 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. //
  3. // Driver for Panasonic AN30259A 3-channel LED driver
  4. //
  5. // Copyright (c) 2018 Simon Shields <simon@lineageos.org>
  6. //
  7. // Datasheet:
  8. // https://www.alliedelec.com/m/d/a9d2b3ee87c2d1a535a41dd747b1c247.pdf
  9. #include <linux/i2c.h>
  10. #include <linux/leds.h>
  11. #include <linux/module.h>
  12. #include <linux/mutex.h>
  13. #include <linux/of.h>
  14. #include <linux/regmap.h>
  15. #define AN30259A_MAX_LEDS 3
  16. #define AN30259A_REG_SRESET 0x00
  17. #define AN30259A_LED_SRESET BIT(0)
  18. /* LED power registers */
  19. #define AN30259A_REG_LED_ON 0x01
  20. #define AN30259A_LED_EN(x) BIT((x) - 1)
  21. #define AN30259A_LED_SLOPE(x) BIT(((x) - 1) + 4)
  22. #define AN30259A_REG_LEDCC(x) (0x03 + ((x) - 1))
  23. /* slope control registers */
  24. #define AN30259A_REG_SLOPE(x) (0x06 + ((x) - 1))
  25. #define AN30259A_LED_SLOPETIME1(x) (x)
  26. #define AN30259A_LED_SLOPETIME2(x) ((x) << 4)
  27. #define AN30259A_REG_LEDCNT1(x) (0x09 + (4 * ((x) - 1)))
  28. #define AN30259A_LED_DUTYMAX(x) ((x) << 4)
  29. #define AN30259A_LED_DUTYMID(x) (x)
  30. #define AN30259A_REG_LEDCNT2(x) (0x0A + (4 * ((x) - 1)))
  31. #define AN30259A_LED_DELAY(x) ((x) << 4)
  32. #define AN30259A_LED_DUTYMIN(x) (x)
  33. /* detention time control (length of each slope step) */
  34. #define AN30259A_REG_LEDCNT3(x) (0x0B + (4 * ((x) - 1)))
  35. #define AN30259A_LED_DT1(x) (x)
  36. #define AN30259A_LED_DT2(x) ((x) << 4)
  37. #define AN30259A_REG_LEDCNT4(x) (0x0C + (4 * ((x) - 1)))
  38. #define AN30259A_LED_DT3(x) (x)
  39. #define AN30259A_LED_DT4(x) ((x) << 4)
  40. #define AN30259A_REG_MAX 0x14
  41. #define AN30259A_BLINK_MAX_TIME 7500 /* ms */
  42. #define AN30259A_SLOPE_RESOLUTION 500 /* ms */
  43. #define AN30259A_NAME "an30259a"
  44. #define STATE_OFF 0
  45. #define STATE_KEEP 1
  46. #define STATE_ON 2
  47. struct an30259a;
  48. struct an30259a_led {
  49. struct an30259a *chip;
  50. struct fwnode_handle *fwnode;
  51. struct led_classdev cdev;
  52. u32 num;
  53. u32 default_state;
  54. bool sloping;
  55. };
  56. struct an30259a {
  57. struct mutex mutex; /* held when writing to registers */
  58. struct i2c_client *client;
  59. struct an30259a_led leds[AN30259A_MAX_LEDS];
  60. struct regmap *regmap;
  61. int num_leds;
  62. };
  63. static int an30259a_brightness_set(struct led_classdev *cdev,
  64. enum led_brightness brightness)
  65. {
  66. struct an30259a_led *led;
  67. int ret;
  68. unsigned int led_on;
  69. led = container_of(cdev, struct an30259a_led, cdev);
  70. mutex_lock(&led->chip->mutex);
  71. ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on);
  72. if (ret)
  73. goto error;
  74. switch (brightness) {
  75. case LED_OFF:
  76. led_on &= ~AN30259A_LED_EN(led->num);
  77. led_on &= ~AN30259A_LED_SLOPE(led->num);
  78. led->sloping = false;
  79. break;
  80. default:
  81. led_on |= AN30259A_LED_EN(led->num);
  82. if (led->sloping)
  83. led_on |= AN30259A_LED_SLOPE(led->num);
  84. ret = regmap_write(led->chip->regmap,
  85. AN30259A_REG_LEDCNT1(led->num),
  86. AN30259A_LED_DUTYMAX(0xf) |
  87. AN30259A_LED_DUTYMID(0xf));
  88. if (ret)
  89. goto error;
  90. break;
  91. }
  92. ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on);
  93. if (ret)
  94. goto error;
  95. ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCC(led->num),
  96. brightness);
  97. error:
  98. mutex_unlock(&led->chip->mutex);
  99. return ret;
  100. }
  101. static int an30259a_blink_set(struct led_classdev *cdev,
  102. unsigned long *delay_off, unsigned long *delay_on)
  103. {
  104. struct an30259a_led *led;
  105. int ret, num;
  106. unsigned int led_on;
  107. unsigned long off = *delay_off, on = *delay_on;
  108. led = container_of(cdev, struct an30259a_led, cdev);
  109. mutex_lock(&led->chip->mutex);
  110. num = led->num;
  111. /* slope time can only be a multiple of 500ms. */
  112. if (off % AN30259A_SLOPE_RESOLUTION || on % AN30259A_SLOPE_RESOLUTION) {
  113. ret = -EINVAL;
  114. goto error;
  115. }
  116. /* up to a maximum of 7500ms. */
  117. if (off > AN30259A_BLINK_MAX_TIME || on > AN30259A_BLINK_MAX_TIME) {
  118. ret = -EINVAL;
  119. goto error;
  120. }
  121. /* if no blink specified, default to 1 Hz. */
  122. if (!off && !on) {
  123. *delay_off = off = 500;
  124. *delay_on = on = 500;
  125. }
  126. /* convert into values the HW will understand. */
  127. off /= AN30259A_SLOPE_RESOLUTION;
  128. on /= AN30259A_SLOPE_RESOLUTION;
  129. /* duty min should be zero (=off), delay should be zero. */
  130. ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT2(num),
  131. AN30259A_LED_DELAY(0) | AN30259A_LED_DUTYMIN(0));
  132. if (ret)
  133. goto error;
  134. /* reset detention time (no "breathing" effect). */
  135. ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT3(num),
  136. AN30259A_LED_DT1(0) | AN30259A_LED_DT2(0));
  137. if (ret)
  138. goto error;
  139. ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT4(num),
  140. AN30259A_LED_DT3(0) | AN30259A_LED_DT4(0));
  141. if (ret)
  142. goto error;
  143. /* slope time controls on/off cycle length. */
  144. ret = regmap_write(led->chip->regmap, AN30259A_REG_SLOPE(num),
  145. AN30259A_LED_SLOPETIME1(off) |
  146. AN30259A_LED_SLOPETIME2(on));
  147. if (ret)
  148. goto error;
  149. /* Finally, enable slope mode. */
  150. ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on);
  151. if (ret)
  152. goto error;
  153. led_on |= AN30259A_LED_SLOPE(num) | AN30259A_LED_EN(led->num);
  154. ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on);
  155. if (!ret)
  156. led->sloping = true;
  157. error:
  158. mutex_unlock(&led->chip->mutex);
  159. return ret;
  160. }
  161. static int an30259a_dt_init(struct i2c_client *client,
  162. struct an30259a *chip)
  163. {
  164. struct device_node *np = dev_of_node(&client->dev), *child;
  165. int count, ret;
  166. int i = 0;
  167. const char *str;
  168. struct an30259a_led *led;
  169. count = of_get_available_child_count(np);
  170. if (!count || count > AN30259A_MAX_LEDS)
  171. return -EINVAL;
  172. for_each_available_child_of_node(np, child) {
  173. u32 source;
  174. ret = of_property_read_u32(child, "reg", &source);
  175. if (ret != 0 || !source || source > AN30259A_MAX_LEDS) {
  176. dev_err(&client->dev, "Couldn't read LED address: %d\n",
  177. ret);
  178. count--;
  179. continue;
  180. }
  181. led = &chip->leds[i];
  182. led->num = source;
  183. led->chip = chip;
  184. led->fwnode = of_fwnode_handle(child);
  185. if (!of_property_read_string(child, "default-state", &str)) {
  186. if (!strcmp(str, "on"))
  187. led->default_state = STATE_ON;
  188. else if (!strcmp(str, "keep"))
  189. led->default_state = STATE_KEEP;
  190. else
  191. led->default_state = STATE_OFF;
  192. }
  193. i++;
  194. }
  195. if (!count)
  196. return -EINVAL;
  197. chip->num_leds = i;
  198. return 0;
  199. }
  200. static const struct regmap_config an30259a_regmap_config = {
  201. .reg_bits = 8,
  202. .val_bits = 8,
  203. .max_register = AN30259A_REG_MAX,
  204. };
  205. static void an30259a_init_default_state(struct an30259a_led *led)
  206. {
  207. struct an30259a *chip = led->chip;
  208. int led_on, err;
  209. switch (led->default_state) {
  210. case STATE_ON:
  211. led->cdev.brightness = LED_FULL;
  212. break;
  213. case STATE_KEEP:
  214. err = regmap_read(chip->regmap, AN30259A_REG_LED_ON, &led_on);
  215. if (err)
  216. break;
  217. if (!(led_on & AN30259A_LED_EN(led->num))) {
  218. led->cdev.brightness = LED_OFF;
  219. break;
  220. }
  221. regmap_read(chip->regmap, AN30259A_REG_LEDCC(led->num),
  222. &led->cdev.brightness);
  223. break;
  224. default:
  225. led->cdev.brightness = LED_OFF;
  226. }
  227. an30259a_brightness_set(&led->cdev, led->cdev.brightness);
  228. }
  229. static int an30259a_probe(struct i2c_client *client)
  230. {
  231. struct an30259a *chip;
  232. int i, err;
  233. chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
  234. if (!chip)
  235. return -ENOMEM;
  236. err = an30259a_dt_init(client, chip);
  237. if (err < 0)
  238. return err;
  239. mutex_init(&chip->mutex);
  240. chip->client = client;
  241. i2c_set_clientdata(client, chip);
  242. chip->regmap = devm_regmap_init_i2c(client, &an30259a_regmap_config);
  243. if (IS_ERR(chip->regmap)) {
  244. err = PTR_ERR(chip->regmap);
  245. dev_err(&client->dev, "Failed to allocate register map: %d\n",
  246. err);
  247. goto exit;
  248. }
  249. for (i = 0; i < chip->num_leds; i++) {
  250. struct led_init_data init_data = {};
  251. an30259a_init_default_state(&chip->leds[i]);
  252. chip->leds[i].cdev.brightness_set_blocking =
  253. an30259a_brightness_set;
  254. chip->leds[i].cdev.blink_set = an30259a_blink_set;
  255. init_data.fwnode = chip->leds[i].fwnode;
  256. init_data.devicename = AN30259A_NAME;
  257. init_data.default_label = ":";
  258. err = devm_led_classdev_register_ext(&client->dev,
  259. &chip->leds[i].cdev,
  260. &init_data);
  261. if (err < 0)
  262. goto exit;
  263. }
  264. return 0;
  265. exit:
  266. mutex_destroy(&chip->mutex);
  267. return err;
  268. }
  269. static int an30259a_remove(struct i2c_client *client)
  270. {
  271. struct an30259a *chip = i2c_get_clientdata(client);
  272. mutex_destroy(&chip->mutex);
  273. return 0;
  274. }
  275. static const struct of_device_id an30259a_match_table[] = {
  276. { .compatible = "panasonic,an30259a", },
  277. { /* sentinel */ },
  278. };
  279. MODULE_DEVICE_TABLE(of, an30259a_match_table);
  280. static const struct i2c_device_id an30259a_id[] = {
  281. { "an30259a", 0 },
  282. { /* sentinel */ },
  283. };
  284. MODULE_DEVICE_TABLE(i2c, an30259a_id);
  285. static struct i2c_driver an30259a_driver = {
  286. .driver = {
  287. .name = "leds-an30259a",
  288. .of_match_table = of_match_ptr(an30259a_match_table),
  289. },
  290. .probe_new = an30259a_probe,
  291. .remove = an30259a_remove,
  292. .id_table = an30259a_id,
  293. };
  294. module_i2c_driver(an30259a_driver);
  295. MODULE_AUTHOR("Simon Shields <simon@lineageos.org>");
  296. MODULE_DESCRIPTION("AN30259A LED driver");
  297. MODULE_LICENSE("GPL v2");