pm8941-wled.c 9.9 KB

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  1. /* Copyright (c) 2015, Sony Mobile Communications, AB.
  2. *
  3. * This program is free software; you can redistribute it and/or modify
  4. * it under the terms of the GNU General Public License version 2 and
  5. * only version 2 as published by the Free Software Foundation.
  6. *
  7. * This program is distributed in the hope that it will be useful,
  8. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  10. * GNU General Public License for more details.
  11. */
  12. #include <linux/kernel.h>
  13. #include <linux/backlight.h>
  14. #include <linux/module.h>
  15. #include <linux/of.h>
  16. #include <linux/of_device.h>
  17. #include <linux/regmap.h>
  18. #define PM8941_WLED_REG_VAL_BASE 0x40
  19. #define PM8941_WLED_REG_VAL_MAX 0xFFF
  20. #define PM8941_WLED_REG_MOD_EN 0x46
  21. #define PM8941_WLED_REG_MOD_EN_BIT BIT(7)
  22. #define PM8941_WLED_REG_MOD_EN_MASK BIT(7)
  23. #define PM8941_WLED_REG_SYNC 0x47
  24. #define PM8941_WLED_REG_SYNC_MASK 0x07
  25. #define PM8941_WLED_REG_SYNC_LED1 BIT(0)
  26. #define PM8941_WLED_REG_SYNC_LED2 BIT(1)
  27. #define PM8941_WLED_REG_SYNC_LED3 BIT(2)
  28. #define PM8941_WLED_REG_SYNC_ALL 0x07
  29. #define PM8941_WLED_REG_SYNC_CLEAR 0x00
  30. #define PM8941_WLED_REG_FREQ 0x4c
  31. #define PM8941_WLED_REG_FREQ_MASK 0x0f
  32. #define PM8941_WLED_REG_OVP 0x4d
  33. #define PM8941_WLED_REG_OVP_MASK 0x03
  34. #define PM8941_WLED_REG_BOOST 0x4e
  35. #define PM8941_WLED_REG_BOOST_MASK 0x07
  36. #define PM8941_WLED_REG_SINK 0x4f
  37. #define PM8941_WLED_REG_SINK_MASK 0xe0
  38. #define PM8941_WLED_REG_SINK_SHFT 0x05
  39. /* Per-'string' registers below */
  40. #define PM8941_WLED_REG_STR_OFFSET 0x10
  41. #define PM8941_WLED_REG_STR_MOD_EN_BASE 0x60
  42. #define PM8941_WLED_REG_STR_MOD_MASK BIT(7)
  43. #define PM8941_WLED_REG_STR_MOD_EN BIT(7)
  44. #define PM8941_WLED_REG_STR_SCALE_BASE 0x62
  45. #define PM8941_WLED_REG_STR_SCALE_MASK 0x1f
  46. #define PM8941_WLED_REG_STR_MOD_SRC_BASE 0x63
  47. #define PM8941_WLED_REG_STR_MOD_SRC_MASK 0x01
  48. #define PM8941_WLED_REG_STR_MOD_SRC_INT 0x00
  49. #define PM8941_WLED_REG_STR_MOD_SRC_EXT 0x01
  50. #define PM8941_WLED_REG_STR_CABC_BASE 0x66
  51. #define PM8941_WLED_REG_STR_CABC_MASK BIT(7)
  52. #define PM8941_WLED_REG_STR_CABC_EN BIT(7)
  53. struct pm8941_wled_config {
  54. u32 i_boost_limit;
  55. u32 ovp;
  56. u32 switch_freq;
  57. u32 num_strings;
  58. u32 i_limit;
  59. bool cs_out_en;
  60. bool ext_gen;
  61. bool cabc_en;
  62. };
  63. struct pm8941_wled {
  64. const char *name;
  65. struct regmap *regmap;
  66. u16 addr;
  67. struct pm8941_wled_config cfg;
  68. };
  69. static int pm8941_wled_update_status(struct backlight_device *bl)
  70. {
  71. struct pm8941_wled *wled = bl_get_data(bl);
  72. u16 val = bl->props.brightness;
  73. u8 ctrl = 0;
  74. int rc;
  75. int i;
  76. if (bl->props.power != FB_BLANK_UNBLANK ||
  77. bl->props.fb_blank != FB_BLANK_UNBLANK ||
  78. bl->props.state & BL_CORE_FBBLANK)
  79. val = 0;
  80. if (val != 0)
  81. ctrl = PM8941_WLED_REG_MOD_EN_BIT;
  82. rc = regmap_update_bits(wled->regmap,
  83. wled->addr + PM8941_WLED_REG_MOD_EN,
  84. PM8941_WLED_REG_MOD_EN_MASK, ctrl);
  85. if (rc)
  86. return rc;
  87. for (i = 0; i < wled->cfg.num_strings; ++i) {
  88. u8 v[2] = { val & 0xff, (val >> 8) & 0xf };
  89. rc = regmap_bulk_write(wled->regmap,
  90. wled->addr + PM8941_WLED_REG_VAL_BASE + 2 * i,
  91. v, 2);
  92. if (rc)
  93. return rc;
  94. }
  95. rc = regmap_update_bits(wled->regmap,
  96. wled->addr + PM8941_WLED_REG_SYNC,
  97. PM8941_WLED_REG_SYNC_MASK, PM8941_WLED_REG_SYNC_ALL);
  98. if (rc)
  99. return rc;
  100. rc = regmap_update_bits(wled->regmap,
  101. wled->addr + PM8941_WLED_REG_SYNC,
  102. PM8941_WLED_REG_SYNC_MASK, PM8941_WLED_REG_SYNC_CLEAR);
  103. return rc;
  104. }
  105. static int pm8941_wled_setup(struct pm8941_wled *wled)
  106. {
  107. int rc;
  108. int i;
  109. rc = regmap_update_bits(wled->regmap,
  110. wled->addr + PM8941_WLED_REG_OVP,
  111. PM8941_WLED_REG_OVP_MASK, wled->cfg.ovp);
  112. if (rc)
  113. return rc;
  114. rc = regmap_update_bits(wled->regmap,
  115. wled->addr + PM8941_WLED_REG_BOOST,
  116. PM8941_WLED_REG_BOOST_MASK, wled->cfg.i_boost_limit);
  117. if (rc)
  118. return rc;
  119. rc = regmap_update_bits(wled->regmap,
  120. wled->addr + PM8941_WLED_REG_FREQ,
  121. PM8941_WLED_REG_FREQ_MASK, wled->cfg.switch_freq);
  122. if (rc)
  123. return rc;
  124. if (wled->cfg.cs_out_en) {
  125. u8 all = (BIT(wled->cfg.num_strings) - 1)
  126. << PM8941_WLED_REG_SINK_SHFT;
  127. rc = regmap_update_bits(wled->regmap,
  128. wled->addr + PM8941_WLED_REG_SINK,
  129. PM8941_WLED_REG_SINK_MASK, all);
  130. if (rc)
  131. return rc;
  132. }
  133. for (i = 0; i < wled->cfg.num_strings; ++i) {
  134. u16 addr = wled->addr + PM8941_WLED_REG_STR_OFFSET * i;
  135. rc = regmap_update_bits(wled->regmap,
  136. addr + PM8941_WLED_REG_STR_MOD_EN_BASE,
  137. PM8941_WLED_REG_STR_MOD_MASK,
  138. PM8941_WLED_REG_STR_MOD_EN);
  139. if (rc)
  140. return rc;
  141. if (wled->cfg.ext_gen) {
  142. rc = regmap_update_bits(wled->regmap,
  143. addr + PM8941_WLED_REG_STR_MOD_SRC_BASE,
  144. PM8941_WLED_REG_STR_MOD_SRC_MASK,
  145. PM8941_WLED_REG_STR_MOD_SRC_EXT);
  146. if (rc)
  147. return rc;
  148. }
  149. rc = regmap_update_bits(wled->regmap,
  150. addr + PM8941_WLED_REG_STR_SCALE_BASE,
  151. PM8941_WLED_REG_STR_SCALE_MASK,
  152. wled->cfg.i_limit);
  153. if (rc)
  154. return rc;
  155. rc = regmap_update_bits(wled->regmap,
  156. addr + PM8941_WLED_REG_STR_CABC_BASE,
  157. PM8941_WLED_REG_STR_CABC_MASK,
  158. wled->cfg.cabc_en ?
  159. PM8941_WLED_REG_STR_CABC_EN : 0);
  160. if (rc)
  161. return rc;
  162. }
  163. return 0;
  164. }
  165. static const struct pm8941_wled_config pm8941_wled_config_defaults = {
  166. .i_boost_limit = 3,
  167. .i_limit = 20,
  168. .ovp = 2,
  169. .switch_freq = 5,
  170. .num_strings = 0,
  171. .cs_out_en = false,
  172. .ext_gen = false,
  173. .cabc_en = false,
  174. };
  175. struct pm8941_wled_var_cfg {
  176. const u32 *values;
  177. u32 (*fn)(u32);
  178. int size;
  179. };
  180. static const u32 pm8941_wled_i_boost_limit_values[] = {
  181. 105, 385, 525, 805, 980, 1260, 1400, 1680,
  182. };
  183. static const struct pm8941_wled_var_cfg pm8941_wled_i_boost_limit_cfg = {
  184. .values = pm8941_wled_i_boost_limit_values,
  185. .size = ARRAY_SIZE(pm8941_wled_i_boost_limit_values),
  186. };
  187. static const u32 pm8941_wled_ovp_values[] = {
  188. 35, 32, 29, 27,
  189. };
  190. static const struct pm8941_wled_var_cfg pm8941_wled_ovp_cfg = {
  191. .values = pm8941_wled_ovp_values,
  192. .size = ARRAY_SIZE(pm8941_wled_ovp_values),
  193. };
  194. static u32 pm8941_wled_num_strings_values_fn(u32 idx)
  195. {
  196. return idx + 1;
  197. }
  198. static const struct pm8941_wled_var_cfg pm8941_wled_num_strings_cfg = {
  199. .fn = pm8941_wled_num_strings_values_fn,
  200. .size = 3,
  201. };
  202. static u32 pm8941_wled_switch_freq_values_fn(u32 idx)
  203. {
  204. return 19200 / (2 * (1 + idx));
  205. }
  206. static const struct pm8941_wled_var_cfg pm8941_wled_switch_freq_cfg = {
  207. .fn = pm8941_wled_switch_freq_values_fn,
  208. .size = 16,
  209. };
  210. static const struct pm8941_wled_var_cfg pm8941_wled_i_limit_cfg = {
  211. .size = 26,
  212. };
  213. static u32 pm8941_wled_values(const struct pm8941_wled_var_cfg *cfg, u32 idx)
  214. {
  215. if (idx >= cfg->size)
  216. return UINT_MAX;
  217. if (cfg->fn)
  218. return cfg->fn(idx);
  219. if (cfg->values)
  220. return cfg->values[idx];
  221. return idx;
  222. }
  223. static int pm8941_wled_configure(struct pm8941_wled *wled, struct device *dev)
  224. {
  225. struct pm8941_wled_config *cfg = &wled->cfg;
  226. u32 val;
  227. int rc;
  228. u32 c;
  229. int i;
  230. int j;
  231. const struct {
  232. const char *name;
  233. u32 *val_ptr;
  234. const struct pm8941_wled_var_cfg *cfg;
  235. } u32_opts[] = {
  236. {
  237. "qcom,current-boost-limit",
  238. &cfg->i_boost_limit,
  239. .cfg = &pm8941_wled_i_boost_limit_cfg,
  240. },
  241. {
  242. "qcom,current-limit",
  243. &cfg->i_limit,
  244. .cfg = &pm8941_wled_i_limit_cfg,
  245. },
  246. {
  247. "qcom,ovp",
  248. &cfg->ovp,
  249. .cfg = &pm8941_wled_ovp_cfg,
  250. },
  251. {
  252. "qcom,switching-freq",
  253. &cfg->switch_freq,
  254. .cfg = &pm8941_wled_switch_freq_cfg,
  255. },
  256. {
  257. "qcom,num-strings",
  258. &cfg->num_strings,
  259. .cfg = &pm8941_wled_num_strings_cfg,
  260. },
  261. };
  262. const struct {
  263. const char *name;
  264. bool *val_ptr;
  265. } bool_opts[] = {
  266. { "qcom,cs-out", &cfg->cs_out_en, },
  267. { "qcom,ext-gen", &cfg->ext_gen, },
  268. { "qcom,cabc", &cfg->cabc_en, },
  269. };
  270. rc = of_property_read_u32(dev->of_node, "reg", &val);
  271. if (rc || val > 0xffff) {
  272. dev_err(dev, "invalid IO resources\n");
  273. return rc ? rc : -EINVAL;
  274. }
  275. wled->addr = val;
  276. rc = of_property_read_string(dev->of_node, "label", &wled->name);
  277. if (rc)
  278. wled->name = dev->of_node->name;
  279. *cfg = pm8941_wled_config_defaults;
  280. for (i = 0; i < ARRAY_SIZE(u32_opts); ++i) {
  281. rc = of_property_read_u32(dev->of_node, u32_opts[i].name, &val);
  282. if (rc == -EINVAL) {
  283. continue;
  284. } else if (rc) {
  285. dev_err(dev, "error reading '%s'\n", u32_opts[i].name);
  286. return rc;
  287. }
  288. c = UINT_MAX;
  289. for (j = 0; c != val; j++) {
  290. c = pm8941_wled_values(u32_opts[i].cfg, j);
  291. if (c == UINT_MAX) {
  292. dev_err(dev, "invalid value for '%s'\n",
  293. u32_opts[i].name);
  294. return -EINVAL;
  295. }
  296. }
  297. dev_dbg(dev, "'%s' = %u\n", u32_opts[i].name, c);
  298. *u32_opts[i].val_ptr = j;
  299. }
  300. for (i = 0; i < ARRAY_SIZE(bool_opts); ++i) {
  301. if (of_property_read_bool(dev->of_node, bool_opts[i].name))
  302. *bool_opts[i].val_ptr = true;
  303. }
  304. cfg->num_strings = cfg->num_strings + 1;
  305. return 0;
  306. }
  307. static const struct backlight_ops pm8941_wled_ops = {
  308. .update_status = pm8941_wled_update_status,
  309. };
  310. static int pm8941_wled_probe(struct platform_device *pdev)
  311. {
  312. struct backlight_properties props;
  313. struct backlight_device *bl;
  314. struct pm8941_wled *wled;
  315. struct regmap *regmap;
  316. int rc;
  317. regmap = dev_get_regmap(pdev->dev.parent, NULL);
  318. if (!regmap) {
  319. dev_err(&pdev->dev, "Unable to get regmap\n");
  320. return -EINVAL;
  321. }
  322. wled = devm_kzalloc(&pdev->dev, sizeof(*wled), GFP_KERNEL);
  323. if (!wled)
  324. return -ENOMEM;
  325. wled->regmap = regmap;
  326. rc = pm8941_wled_configure(wled, &pdev->dev);
  327. if (rc)
  328. return rc;
  329. rc = pm8941_wled_setup(wled);
  330. if (rc)
  331. return rc;
  332. memset(&props, 0, sizeof(struct backlight_properties));
  333. props.type = BACKLIGHT_RAW;
  334. props.max_brightness = PM8941_WLED_REG_VAL_MAX;
  335. bl = devm_backlight_device_register(&pdev->dev, wled->name,
  336. &pdev->dev, wled,
  337. &pm8941_wled_ops, &props);
  338. if (IS_ERR(bl))
  339. return PTR_ERR(bl);
  340. return 0;
  341. };
  342. static const struct of_device_id pm8941_wled_match_table[] = {
  343. { .compatible = "qcom,pm8941-wled" },
  344. {}
  345. };
  346. MODULE_DEVICE_TABLE(of, pm8941_wled_match_table);
  347. static struct platform_driver pm8941_wled_driver = {
  348. .probe = pm8941_wled_probe,
  349. .driver = {
  350. .name = "pm8941-wled",
  351. .of_match_table = pm8941_wled_match_table,
  352. },
  353. };
  354. module_platform_driver(pm8941_wled_driver);
  355. MODULE_DESCRIPTION("pm8941 wled driver");
  356. MODULE_LICENSE("GPL v2");