leds-el15203000.c 8.7 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. // Copyright (c) 2019 Crane Merchandising Systems. All rights reserved.
  3. // Copyright (C) 2019 Oleh Kravchenko <oleg@kaa.org.ua>
  4. #include <linux/delay.h>
  5. #include <linux/leds.h>
  6. #include <linux/module.h>
  7. #include <linux/of_device.h>
  8. #include <linux/spi/spi.h>
  9. /*
  10. * EL15203000 SPI protocol description:
  11. * +-----+---------+
  12. * | LED | COMMAND |
  13. * +-----+---------+
  14. * | 1 | 1 |
  15. * +-----+---------+
  16. * (*) LEDs MCU board expects 20 msec delay per byte.
  17. *
  18. * LEDs:
  19. * +----------+--------------+-------------------------------------------+
  20. * | ID | NAME | DESCRIPTION |
  21. * +----------+--------------+-------------------------------------------+
  22. * | 'P' 0x50 | Pipe | Consists from 5 LEDs, controlled by board |
  23. * +----------+--------------+-------------------------------------------+
  24. * | 'S' 0x53 | Screen frame | Light tube around the screen |
  25. * +----------+--------------+-------------------------------------------+
  26. * | 'V' 0x56 | Vending area | Highlights a cup of coffee |
  27. * +----------+--------------+-------------------------------------------+
  28. *
  29. * COMMAND:
  30. * +----------+-----------------+--------------+--------------+
  31. * | VALUES | PIPE | SCREEN FRAME | VENDING AREA |
  32. * +----------+-----------------+--------------+--------------+
  33. * | '0' 0x30 | Off |
  34. * +----------+-----------------------------------------------+
  35. * | '1' 0x31 | On |
  36. * +----------+-----------------+--------------+--------------+
  37. * | '2' 0x32 | Cascade | Breathing |
  38. * +----------+-----------------+--------------+
  39. * | '3' 0x33 | Inverse cascade |
  40. * +----------+-----------------+
  41. * | '4' 0x34 | Bounce |
  42. * +----------+-----------------+
  43. * | '5' 0x35 | Inverse bounce |
  44. * +----------+-----------------+
  45. */
  46. /* EL15203000 default settings */
  47. #define EL_FW_DELAY_USEC 20000ul
  48. #define EL_PATTERN_DELAY_MSEC 800u
  49. #define EL_PATTERN_LEN 10u
  50. #define EL_PATTERN_HALF_LEN (EL_PATTERN_LEN / 2)
  51. enum el15203000_command {
  52. /* for all LEDs */
  53. EL_OFF = '0',
  54. EL_ON = '1',
  55. /* for Screen LED */
  56. EL_SCREEN_BREATHING = '2',
  57. /* for Pipe LED */
  58. EL_PIPE_CASCADE = '2',
  59. EL_PIPE_INV_CASCADE = '3',
  60. EL_PIPE_BOUNCE = '4',
  61. EL_PIPE_INV_BOUNCE = '5',
  62. };
  63. struct el15203000_led {
  64. struct el15203000 *priv;
  65. struct led_classdev ldev;
  66. u32 reg;
  67. };
  68. struct el15203000 {
  69. struct device *dev;
  70. struct mutex lock;
  71. struct spi_device *spi;
  72. unsigned long delay;
  73. size_t count;
  74. struct el15203000_led leds[];
  75. };
  76. static int el15203000_cmd(struct el15203000_led *led, u8 brightness)
  77. {
  78. int ret;
  79. u8 cmd[2];
  80. size_t i;
  81. mutex_lock(&led->priv->lock);
  82. dev_dbg(led->priv->dev, "Set brightness of 0x%02x(%c) to 0x%02x(%c)",
  83. led->reg, led->reg, brightness, brightness);
  84. /* to avoid SPI mistiming with firmware we should wait some time */
  85. if (time_after(led->priv->delay, jiffies)) {
  86. dev_dbg(led->priv->dev, "Wait %luus to sync",
  87. EL_FW_DELAY_USEC);
  88. usleep_range(EL_FW_DELAY_USEC,
  89. EL_FW_DELAY_USEC + 1);
  90. }
  91. cmd[0] = led->reg;
  92. cmd[1] = brightness;
  93. for (i = 0; i < ARRAY_SIZE(cmd); i++) {
  94. if (i)
  95. usleep_range(EL_FW_DELAY_USEC,
  96. EL_FW_DELAY_USEC + 1);
  97. ret = spi_write(led->priv->spi, &cmd[i], sizeof(cmd[i]));
  98. if (ret) {
  99. dev_err(led->priv->dev,
  100. "spi_write() error %d", ret);
  101. break;
  102. }
  103. }
  104. led->priv->delay = jiffies + usecs_to_jiffies(EL_FW_DELAY_USEC);
  105. mutex_unlock(&led->priv->lock);
  106. return ret;
  107. }
  108. static int el15203000_set_blocking(struct led_classdev *ldev,
  109. enum led_brightness brightness)
  110. {
  111. struct el15203000_led *led = container_of(ldev,
  112. struct el15203000_led,
  113. ldev);
  114. return el15203000_cmd(led, brightness == LED_OFF ? EL_OFF : EL_ON);
  115. }
  116. static int el15203000_pattern_set_S(struct led_classdev *ldev,
  117. struct led_pattern *pattern,
  118. u32 len, int repeat)
  119. {
  120. struct el15203000_led *led = container_of(ldev,
  121. struct el15203000_led,
  122. ldev);
  123. if (repeat > 0 || len != 2 ||
  124. pattern[0].delta_t != 4000 || pattern[0].brightness != 0 ||
  125. pattern[1].delta_t != 4000 || pattern[1].brightness != 1)
  126. return -EINVAL;
  127. dev_dbg(led->priv->dev, "Breathing mode for 0x%02x(%c)",
  128. led->reg, led->reg);
  129. return el15203000_cmd(led, EL_SCREEN_BREATHING);
  130. }
  131. static bool is_cascade(const struct led_pattern *pattern, u32 len,
  132. bool inv, bool right)
  133. {
  134. int val, t;
  135. u32 i;
  136. if (len != EL_PATTERN_HALF_LEN)
  137. return false;
  138. val = right ? BIT(4) : BIT(0);
  139. for (i = 0; i < len; i++) {
  140. t = inv ? ~val & GENMASK(4, 0) : val;
  141. if (pattern[i].delta_t != EL_PATTERN_DELAY_MSEC ||
  142. pattern[i].brightness != t)
  143. return false;
  144. val = right ? val >> 1 : val << 1;
  145. }
  146. return true;
  147. }
  148. static bool is_bounce(const struct led_pattern *pattern, u32 len, bool inv)
  149. {
  150. if (len != EL_PATTERN_LEN)
  151. return false;
  152. return is_cascade(pattern, EL_PATTERN_HALF_LEN, inv, false) &&
  153. is_cascade(pattern + EL_PATTERN_HALF_LEN,
  154. EL_PATTERN_HALF_LEN, inv, true);
  155. }
  156. static int el15203000_pattern_set_P(struct led_classdev *ldev,
  157. struct led_pattern *pattern,
  158. u32 len, int repeat)
  159. {
  160. u8 cmd;
  161. struct el15203000_led *led = container_of(ldev,
  162. struct el15203000_led,
  163. ldev);
  164. if (repeat > 0)
  165. return -EINVAL;
  166. if (is_cascade(pattern, len, false, false)) {
  167. dev_dbg(led->priv->dev, "Cascade mode for 0x%02x(%c)",
  168. led->reg, led->reg);
  169. cmd = EL_PIPE_CASCADE;
  170. } else if (is_cascade(pattern, len, true, false)) {
  171. dev_dbg(led->priv->dev, "Inverse cascade mode for 0x%02x(%c)",
  172. led->reg, led->reg);
  173. cmd = EL_PIPE_INV_CASCADE;
  174. } else if (is_bounce(pattern, len, false)) {
  175. dev_dbg(led->priv->dev, "Bounce mode for 0x%02x(%c)",
  176. led->reg, led->reg);
  177. cmd = EL_PIPE_BOUNCE;
  178. } else if (is_bounce(pattern, len, true)) {
  179. dev_dbg(led->priv->dev, "Inverse bounce mode for 0x%02x(%c)",
  180. led->reg, led->reg);
  181. cmd = EL_PIPE_INV_BOUNCE;
  182. } else {
  183. dev_err(led->priv->dev, "Invalid hw_pattern for 0x%02x(%c)!",
  184. led->reg, led->reg);
  185. return -EINVAL;
  186. }
  187. return el15203000_cmd(led, cmd);
  188. }
  189. static int el15203000_pattern_clear(struct led_classdev *ldev)
  190. {
  191. struct el15203000_led *led = container_of(ldev,
  192. struct el15203000_led,
  193. ldev);
  194. return el15203000_cmd(led, EL_OFF);
  195. }
  196. static int el15203000_probe_dt(struct el15203000 *priv)
  197. {
  198. struct el15203000_led *led = priv->leds;
  199. struct fwnode_handle *child;
  200. int ret;
  201. device_for_each_child_node(priv->dev, child) {
  202. struct led_init_data init_data = {};
  203. ret = fwnode_property_read_u32(child, "reg", &led->reg);
  204. if (ret) {
  205. dev_err(priv->dev, "LED without ID number");
  206. fwnode_handle_put(child);
  207. break;
  208. }
  209. if (led->reg > U8_MAX) {
  210. dev_err(priv->dev, "LED value %d is invalid", led->reg);
  211. fwnode_handle_put(child);
  212. return -EINVAL;
  213. }
  214. led->priv = priv;
  215. led->ldev.max_brightness = LED_ON;
  216. led->ldev.brightness_set_blocking = el15203000_set_blocking;
  217. if (led->reg == 'S') {
  218. led->ldev.pattern_set = el15203000_pattern_set_S;
  219. led->ldev.pattern_clear = el15203000_pattern_clear;
  220. } else if (led->reg == 'P') {
  221. led->ldev.pattern_set = el15203000_pattern_set_P;
  222. led->ldev.pattern_clear = el15203000_pattern_clear;
  223. }
  224. init_data.fwnode = child;
  225. ret = devm_led_classdev_register_ext(priv->dev, &led->ldev,
  226. &init_data);
  227. if (ret) {
  228. dev_err(priv->dev,
  229. "failed to register LED device %s, err %d",
  230. led->ldev.name, ret);
  231. fwnode_handle_put(child);
  232. break;
  233. }
  234. led++;
  235. }
  236. return ret;
  237. }
  238. static int el15203000_probe(struct spi_device *spi)
  239. {
  240. struct el15203000 *priv;
  241. size_t count;
  242. count = device_get_child_node_count(&spi->dev);
  243. if (!count) {
  244. dev_err(&spi->dev, "LEDs are not defined in device tree!");
  245. return -ENODEV;
  246. }
  247. priv = devm_kzalloc(&spi->dev, struct_size(priv, leds, count),
  248. GFP_KERNEL);
  249. if (!priv)
  250. return -ENOMEM;
  251. mutex_init(&priv->lock);
  252. priv->count = count;
  253. priv->dev = &spi->dev;
  254. priv->spi = spi;
  255. priv->delay = jiffies -
  256. usecs_to_jiffies(EL_FW_DELAY_USEC);
  257. spi_set_drvdata(spi, priv);
  258. return el15203000_probe_dt(priv);
  259. }
  260. static int el15203000_remove(struct spi_device *spi)
  261. {
  262. struct el15203000 *priv = spi_get_drvdata(spi);
  263. mutex_destroy(&priv->lock);
  264. return 0;
  265. }
  266. static const struct of_device_id el15203000_dt_ids[] = {
  267. { .compatible = "crane,el15203000", },
  268. {},
  269. };
  270. MODULE_DEVICE_TABLE(of, el15203000_dt_ids);
  271. static struct spi_driver el15203000_driver = {
  272. .probe = el15203000_probe,
  273. .remove = el15203000_remove,
  274. .driver = {
  275. .name = KBUILD_MODNAME,
  276. .of_match_table = el15203000_dt_ids,
  277. },
  278. };
  279. module_spi_driver(el15203000_driver);
  280. MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>");
  281. MODULE_DESCRIPTION("el15203000 LED driver");
  282. MODULE_LICENSE("GPL v2");
  283. MODULE_ALIAS("spi:el15203000");