leds-lm3530.c 13 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Copyright (C) 2011 ST-Ericsson SA.
  4. * Copyright (C) 2009 Motorola, Inc.
  5. *
  6. * Simple driver for National Semiconductor LM3530 Backlight driver chip
  7. *
  8. * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
  9. * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
  10. */
  11. #include <linux/i2c.h>
  12. #include <linux/leds.h>
  13. #include <linux/slab.h>
  14. #include <linux/platform_device.h>
  15. #include <linux/input.h>
  16. #include <linux/led-lm3530.h>
  17. #include <linux/types.h>
  18. #include <linux/regulator/consumer.h>
  19. #include <linux/module.h>
  20. #define LM3530_LED_DEV "lcd-backlight"
  21. #define LM3530_NAME "lm3530-led"
  22. #define LM3530_GEN_CONFIG 0x10
  23. #define LM3530_ALS_CONFIG 0x20
  24. #define LM3530_BRT_RAMP_RATE 0x30
  25. #define LM3530_ALS_IMP_SELECT 0x41
  26. #define LM3530_BRT_CTRL_REG 0xA0
  27. #define LM3530_ALS_ZB0_REG 0x60
  28. #define LM3530_ALS_ZB1_REG 0x61
  29. #define LM3530_ALS_ZB2_REG 0x62
  30. #define LM3530_ALS_ZB3_REG 0x63
  31. #define LM3530_ALS_Z0T_REG 0x70
  32. #define LM3530_ALS_Z1T_REG 0x71
  33. #define LM3530_ALS_Z2T_REG 0x72
  34. #define LM3530_ALS_Z3T_REG 0x73
  35. #define LM3530_ALS_Z4T_REG 0x74
  36. #define LM3530_REG_MAX 14
  37. /* General Control Register */
  38. #define LM3530_EN_I2C_SHIFT (0)
  39. #define LM3530_RAMP_LAW_SHIFT (1)
  40. #define LM3530_MAX_CURR_SHIFT (2)
  41. #define LM3530_EN_PWM_SHIFT (5)
  42. #define LM3530_PWM_POL_SHIFT (6)
  43. #define LM3530_EN_PWM_SIMPLE_SHIFT (7)
  44. #define LM3530_ENABLE_I2C (1 << LM3530_EN_I2C_SHIFT)
  45. #define LM3530_ENABLE_PWM (1 << LM3530_EN_PWM_SHIFT)
  46. #define LM3530_POL_LOW (1 << LM3530_PWM_POL_SHIFT)
  47. #define LM3530_ENABLE_PWM_SIMPLE (1 << LM3530_EN_PWM_SIMPLE_SHIFT)
  48. /* ALS Config Register Options */
  49. #define LM3530_ALS_AVG_TIME_SHIFT (0)
  50. #define LM3530_EN_ALS_SHIFT (3)
  51. #define LM3530_ALS_SEL_SHIFT (5)
  52. #define LM3530_ENABLE_ALS (3 << LM3530_EN_ALS_SHIFT)
  53. /* Brightness Ramp Rate Register */
  54. #define LM3530_BRT_RAMP_FALL_SHIFT (0)
  55. #define LM3530_BRT_RAMP_RISE_SHIFT (3)
  56. /* ALS Resistor Select */
  57. #define LM3530_ALS1_IMP_SHIFT (0)
  58. #define LM3530_ALS2_IMP_SHIFT (4)
  59. /* Zone Boundary Register defaults */
  60. #define LM3530_ALS_ZB_MAX (4)
  61. #define LM3530_ALS_WINDOW_mV (1000)
  62. #define LM3530_ALS_OFFSET_mV (4)
  63. /* Zone Target Register defaults */
  64. #define LM3530_DEF_ZT_0 (0x7F)
  65. #define LM3530_DEF_ZT_1 (0x66)
  66. #define LM3530_DEF_ZT_2 (0x4C)
  67. #define LM3530_DEF_ZT_3 (0x33)
  68. #define LM3530_DEF_ZT_4 (0x19)
  69. /* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */
  70. #define MAX_BRIGHTNESS (127)
  71. struct lm3530_mode_map {
  72. const char *mode;
  73. enum lm3530_mode mode_val;
  74. };
  75. static struct lm3530_mode_map mode_map[] = {
  76. { "man", LM3530_BL_MODE_MANUAL },
  77. { "als", LM3530_BL_MODE_ALS },
  78. { "pwm", LM3530_BL_MODE_PWM },
  79. };
  80. /**
  81. * struct lm3530_data
  82. * @led_dev: led class device
  83. * @client: i2c client
  84. * @pdata: LM3530 platform data
  85. * @mode: mode of operation - manual, ALS, PWM
  86. * @regulator: regulator
  87. * @brighness: previous brightness value
  88. * @enable: regulator is enabled
  89. */
  90. struct lm3530_data {
  91. struct led_classdev led_dev;
  92. struct i2c_client *client;
  93. struct lm3530_platform_data *pdata;
  94. enum lm3530_mode mode;
  95. struct regulator *regulator;
  96. enum led_brightness brightness;
  97. bool enable;
  98. };
  99. /*
  100. * struct lm3530_als_data
  101. * @config : value of ALS configuration register
  102. * @imp_sel : value of ALS resistor select register
  103. * @zone : values of ALS ZB(Zone Boundary) registers
  104. */
  105. struct lm3530_als_data {
  106. u8 config;
  107. u8 imp_sel;
  108. u8 zones[LM3530_ALS_ZB_MAX];
  109. };
  110. static const u8 lm3530_reg[LM3530_REG_MAX] = {
  111. LM3530_GEN_CONFIG,
  112. LM3530_ALS_CONFIG,
  113. LM3530_BRT_RAMP_RATE,
  114. LM3530_ALS_IMP_SELECT,
  115. LM3530_BRT_CTRL_REG,
  116. LM3530_ALS_ZB0_REG,
  117. LM3530_ALS_ZB1_REG,
  118. LM3530_ALS_ZB2_REG,
  119. LM3530_ALS_ZB3_REG,
  120. LM3530_ALS_Z0T_REG,
  121. LM3530_ALS_Z1T_REG,
  122. LM3530_ALS_Z2T_REG,
  123. LM3530_ALS_Z3T_REG,
  124. LM3530_ALS_Z4T_REG,
  125. };
  126. static int lm3530_get_mode_from_str(const char *str)
  127. {
  128. int i;
  129. for (i = 0; i < ARRAY_SIZE(mode_map); i++)
  130. if (sysfs_streq(str, mode_map[i].mode))
  131. return mode_map[i].mode_val;
  132. return -EINVAL;
  133. }
  134. static void lm3530_als_configure(struct lm3530_platform_data *pdata,
  135. struct lm3530_als_data *als)
  136. {
  137. int i;
  138. u32 als_vmin, als_vmax, als_vstep;
  139. if (pdata->als_vmax == 0) {
  140. pdata->als_vmin = 0;
  141. pdata->als_vmax = LM3530_ALS_WINDOW_mV;
  142. }
  143. als_vmin = pdata->als_vmin;
  144. als_vmax = pdata->als_vmax;
  145. if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
  146. pdata->als_vmax = als_vmax = als_vmin + LM3530_ALS_WINDOW_mV;
  147. /* n zone boundary makes n+1 zones */
  148. als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
  149. for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
  150. als->zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
  151. als_vstep + (i * als_vstep)) * LED_FULL) / 1000;
  152. als->config =
  153. (pdata->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
  154. (LM3530_ENABLE_ALS) |
  155. (pdata->als_input_mode << LM3530_ALS_SEL_SHIFT);
  156. als->imp_sel =
  157. (pdata->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
  158. (pdata->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
  159. }
  160. static int lm3530_led_enable(struct lm3530_data *drvdata)
  161. {
  162. int ret;
  163. if (drvdata->enable)
  164. return 0;
  165. ret = regulator_enable(drvdata->regulator);
  166. if (ret) {
  167. dev_err(drvdata->led_dev.dev, "Failed to enable vin:%d\n", ret);
  168. return ret;
  169. }
  170. drvdata->enable = true;
  171. return 0;
  172. }
  173. static void lm3530_led_disable(struct lm3530_data *drvdata)
  174. {
  175. int ret;
  176. if (!drvdata->enable)
  177. return;
  178. ret = regulator_disable(drvdata->regulator);
  179. if (ret) {
  180. dev_err(drvdata->led_dev.dev, "Failed to disable vin:%d\n",
  181. ret);
  182. return;
  183. }
  184. drvdata->enable = false;
  185. }
  186. static int lm3530_init_registers(struct lm3530_data *drvdata)
  187. {
  188. int ret = 0;
  189. int i;
  190. u8 gen_config;
  191. u8 brt_ramp;
  192. u8 brightness;
  193. u8 reg_val[LM3530_REG_MAX];
  194. struct lm3530_platform_data *pdata = drvdata->pdata;
  195. struct i2c_client *client = drvdata->client;
  196. struct lm3530_pwm_data *pwm = &pdata->pwm_data;
  197. struct lm3530_als_data als;
  198. memset(&als, 0, sizeof(struct lm3530_als_data));
  199. gen_config = (pdata->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
  200. ((pdata->max_current & 7) << LM3530_MAX_CURR_SHIFT);
  201. switch (drvdata->mode) {
  202. case LM3530_BL_MODE_MANUAL:
  203. gen_config |= LM3530_ENABLE_I2C;
  204. break;
  205. case LM3530_BL_MODE_ALS:
  206. gen_config |= LM3530_ENABLE_I2C;
  207. lm3530_als_configure(pdata, &als);
  208. break;
  209. case LM3530_BL_MODE_PWM:
  210. gen_config |= LM3530_ENABLE_PWM | LM3530_ENABLE_PWM_SIMPLE |
  211. (pdata->pwm_pol_hi << LM3530_PWM_POL_SHIFT);
  212. break;
  213. }
  214. brt_ramp = (pdata->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
  215. (pdata->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
  216. if (drvdata->brightness)
  217. brightness = drvdata->brightness;
  218. else
  219. brightness = drvdata->brightness = pdata->brt_val;
  220. if (brightness > drvdata->led_dev.max_brightness)
  221. brightness = drvdata->led_dev.max_brightness;
  222. reg_val[0] = gen_config; /* LM3530_GEN_CONFIG */
  223. reg_val[1] = als.config; /* LM3530_ALS_CONFIG */
  224. reg_val[2] = brt_ramp; /* LM3530_BRT_RAMP_RATE */
  225. reg_val[3] = als.imp_sel; /* LM3530_ALS_IMP_SELECT */
  226. reg_val[4] = brightness; /* LM3530_BRT_CTRL_REG */
  227. reg_val[5] = als.zones[0]; /* LM3530_ALS_ZB0_REG */
  228. reg_val[6] = als.zones[1]; /* LM3530_ALS_ZB1_REG */
  229. reg_val[7] = als.zones[2]; /* LM3530_ALS_ZB2_REG */
  230. reg_val[8] = als.zones[3]; /* LM3530_ALS_ZB3_REG */
  231. reg_val[9] = LM3530_DEF_ZT_0; /* LM3530_ALS_Z0T_REG */
  232. reg_val[10] = LM3530_DEF_ZT_1; /* LM3530_ALS_Z1T_REG */
  233. reg_val[11] = LM3530_DEF_ZT_2; /* LM3530_ALS_Z2T_REG */
  234. reg_val[12] = LM3530_DEF_ZT_3; /* LM3530_ALS_Z3T_REG */
  235. reg_val[13] = LM3530_DEF_ZT_4; /* LM3530_ALS_Z4T_REG */
  236. ret = lm3530_led_enable(drvdata);
  237. if (ret)
  238. return ret;
  239. for (i = 0; i < LM3530_REG_MAX; i++) {
  240. /* do not update brightness register when pwm mode */
  241. if (lm3530_reg[i] == LM3530_BRT_CTRL_REG &&
  242. drvdata->mode == LM3530_BL_MODE_PWM) {
  243. if (pwm->pwm_set_intensity)
  244. pwm->pwm_set_intensity(reg_val[i],
  245. drvdata->led_dev.max_brightness);
  246. continue;
  247. }
  248. ret = i2c_smbus_write_byte_data(client,
  249. lm3530_reg[i], reg_val[i]);
  250. if (ret)
  251. break;
  252. }
  253. return ret;
  254. }
  255. static void lm3530_brightness_set(struct led_classdev *led_cdev,
  256. enum led_brightness brt_val)
  257. {
  258. int err;
  259. struct lm3530_data *drvdata =
  260. container_of(led_cdev, struct lm3530_data, led_dev);
  261. struct lm3530_platform_data *pdata = drvdata->pdata;
  262. struct lm3530_pwm_data *pwm = &pdata->pwm_data;
  263. u8 max_brightness = led_cdev->max_brightness;
  264. switch (drvdata->mode) {
  265. case LM3530_BL_MODE_MANUAL:
  266. if (!drvdata->enable) {
  267. err = lm3530_init_registers(drvdata);
  268. if (err) {
  269. dev_err(&drvdata->client->dev,
  270. "Register Init failed: %d\n", err);
  271. break;
  272. }
  273. }
  274. /* set the brightness in brightness control register*/
  275. err = i2c_smbus_write_byte_data(drvdata->client,
  276. LM3530_BRT_CTRL_REG, brt_val);
  277. if (err)
  278. dev_err(&drvdata->client->dev,
  279. "Unable to set brightness: %d\n", err);
  280. else
  281. drvdata->brightness = brt_val;
  282. if (brt_val == 0)
  283. lm3530_led_disable(drvdata);
  284. break;
  285. case LM3530_BL_MODE_ALS:
  286. break;
  287. case LM3530_BL_MODE_PWM:
  288. if (pwm->pwm_set_intensity)
  289. pwm->pwm_set_intensity(brt_val, max_brightness);
  290. break;
  291. default:
  292. break;
  293. }
  294. }
  295. static ssize_t lm3530_mode_get(struct device *dev,
  296. struct device_attribute *attr, char *buf)
  297. {
  298. struct led_classdev *led_cdev = dev_get_drvdata(dev);
  299. struct lm3530_data *drvdata;
  300. int i, len = 0;
  301. drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
  302. for (i = 0; i < ARRAY_SIZE(mode_map); i++)
  303. if (drvdata->mode == mode_map[i].mode_val)
  304. len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
  305. else
  306. len += sprintf(buf + len, "%s ", mode_map[i].mode);
  307. len += sprintf(buf + len, "\n");
  308. return len;
  309. }
  310. static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
  311. *attr, const char *buf, size_t size)
  312. {
  313. struct led_classdev *led_cdev = dev_get_drvdata(dev);
  314. struct lm3530_data *drvdata;
  315. struct lm3530_pwm_data *pwm;
  316. u8 max_brightness;
  317. int mode, err;
  318. drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
  319. pwm = &drvdata->pdata->pwm_data;
  320. max_brightness = led_cdev->max_brightness;
  321. mode = lm3530_get_mode_from_str(buf);
  322. if (mode < 0) {
  323. dev_err(dev, "Invalid mode\n");
  324. return mode;
  325. }
  326. drvdata->mode = mode;
  327. /* set pwm to low if unnecessary */
  328. if (mode != LM3530_BL_MODE_PWM && pwm->pwm_set_intensity)
  329. pwm->pwm_set_intensity(0, max_brightness);
  330. err = lm3530_init_registers(drvdata);
  331. if (err) {
  332. dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
  333. return err;
  334. }
  335. return sizeof(drvdata->mode);
  336. }
  337. static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set);
  338. static struct attribute *lm3530_attrs[] = {
  339. &dev_attr_mode.attr,
  340. NULL
  341. };
  342. ATTRIBUTE_GROUPS(lm3530);
  343. static int lm3530_probe(struct i2c_client *client,
  344. const struct i2c_device_id *id)
  345. {
  346. struct lm3530_platform_data *pdata = dev_get_platdata(&client->dev);
  347. struct lm3530_data *drvdata;
  348. int err = 0;
  349. if (pdata == NULL) {
  350. dev_err(&client->dev, "platform data required\n");
  351. return -ENODEV;
  352. }
  353. /* BL mode */
  354. if (pdata->mode > LM3530_BL_MODE_PWM) {
  355. dev_err(&client->dev, "Illegal Mode request\n");
  356. return -EINVAL;
  357. }
  358. if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
  359. dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
  360. return -EIO;
  361. }
  362. drvdata = devm_kzalloc(&client->dev, sizeof(struct lm3530_data),
  363. GFP_KERNEL);
  364. if (drvdata == NULL)
  365. return -ENOMEM;
  366. drvdata->mode = pdata->mode;
  367. drvdata->client = client;
  368. drvdata->pdata = pdata;
  369. drvdata->brightness = LED_OFF;
  370. drvdata->enable = false;
  371. drvdata->led_dev.name = LM3530_LED_DEV;
  372. drvdata->led_dev.brightness_set = lm3530_brightness_set;
  373. drvdata->led_dev.max_brightness = MAX_BRIGHTNESS;
  374. drvdata->led_dev.groups = lm3530_groups;
  375. i2c_set_clientdata(client, drvdata);
  376. drvdata->regulator = devm_regulator_get(&client->dev, "vin");
  377. if (IS_ERR(drvdata->regulator)) {
  378. dev_err(&client->dev, "regulator get failed\n");
  379. err = PTR_ERR(drvdata->regulator);
  380. drvdata->regulator = NULL;
  381. return err;
  382. }
  383. if (drvdata->pdata->brt_val) {
  384. err = lm3530_init_registers(drvdata);
  385. if (err < 0) {
  386. dev_err(&client->dev,
  387. "Register Init failed: %d\n", err);
  388. return err;
  389. }
  390. }
  391. err = led_classdev_register(&client->dev, &drvdata->led_dev);
  392. if (err < 0) {
  393. dev_err(&client->dev, "Register led class failed: %d\n", err);
  394. return err;
  395. }
  396. return 0;
  397. }
  398. static int lm3530_remove(struct i2c_client *client)
  399. {
  400. struct lm3530_data *drvdata = i2c_get_clientdata(client);
  401. lm3530_led_disable(drvdata);
  402. led_classdev_unregister(&drvdata->led_dev);
  403. return 0;
  404. }
  405. static const struct i2c_device_id lm3530_id[] = {
  406. {LM3530_NAME, 0},
  407. {}
  408. };
  409. MODULE_DEVICE_TABLE(i2c, lm3530_id);
  410. static struct i2c_driver lm3530_i2c_driver = {
  411. .probe = lm3530_probe,
  412. .remove = lm3530_remove,
  413. .id_table = lm3530_id,
  414. .driver = {
  415. .name = LM3530_NAME,
  416. },
  417. };
  418. module_i2c_driver(lm3530_i2c_driver);
  419. MODULE_DESCRIPTION("Back Light driver for LM3530");
  420. MODULE_LICENSE("GPL v2");
  421. MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");