leds-gpio.c 7.7 KB

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  1. /*
  2. * LEDs driver for GPIOs
  3. *
  4. * Copyright (C) 2007 8D Technologies inc.
  5. * Raphael Assenat <raph@8d.com>
  6. * Copyright (C) 2008 Freescale Semiconductor, Inc.
  7. *
  8. * This program is free software; you can redistribute it and/or modify
  9. * it under the terms of the GNU General Public License version 2 as
  10. * published by the Free Software Foundation.
  11. *
  12. */
  13. #include <linux/err.h>
  14. #include <linux/gpio.h>
  15. #include <linux/gpio/consumer.h>
  16. #include <linux/kernel.h>
  17. #include <linux/leds.h>
  18. #include <linux/module.h>
  19. #include <linux/of.h>
  20. #include <linux/platform_device.h>
  21. #include <linux/property.h>
  22. #include <linux/slab.h>
  23. struct gpio_led_data {
  24. struct led_classdev cdev;
  25. struct gpio_desc *gpiod;
  26. u8 can_sleep;
  27. u8 blinking;
  28. int (*platform_gpio_blink_set)(struct gpio_desc *desc, int state,
  29. unsigned long *delay_on, unsigned long *delay_off);
  30. };
  31. static void gpio_led_set(struct led_classdev *led_cdev,
  32. enum led_brightness value)
  33. {
  34. struct gpio_led_data *led_dat =
  35. container_of(led_cdev, struct gpio_led_data, cdev);
  36. int level;
  37. if (value == LED_OFF)
  38. level = 0;
  39. else
  40. level = 1;
  41. if (led_dat->blinking) {
  42. led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
  43. NULL, NULL);
  44. led_dat->blinking = 0;
  45. } else {
  46. if (led_dat->can_sleep)
  47. gpiod_set_value_cansleep(led_dat->gpiod, level);
  48. else
  49. gpiod_set_value(led_dat->gpiod, level);
  50. }
  51. }
  52. static int gpio_led_set_blocking(struct led_classdev *led_cdev,
  53. enum led_brightness value)
  54. {
  55. gpio_led_set(led_cdev, value);
  56. return 0;
  57. }
  58. static int gpio_blink_set(struct led_classdev *led_cdev,
  59. unsigned long *delay_on, unsigned long *delay_off)
  60. {
  61. struct gpio_led_data *led_dat =
  62. container_of(led_cdev, struct gpio_led_data, cdev);
  63. led_dat->blinking = 1;
  64. return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
  65. delay_on, delay_off);
  66. }
  67. static int create_gpio_led(const struct gpio_led *template,
  68. struct gpio_led_data *led_dat, struct device *parent,
  69. int (*blink_set)(struct gpio_desc *, int, unsigned long *,
  70. unsigned long *))
  71. {
  72. int ret, state;
  73. led_dat->gpiod = template->gpiod;
  74. if (!led_dat->gpiod) {
  75. /*
  76. * This is the legacy code path for platform code that
  77. * still uses GPIO numbers. Ultimately we would like to get
  78. * rid of this block completely.
  79. */
  80. unsigned long flags = GPIOF_OUT_INIT_LOW;
  81. /* skip leds that aren't available */
  82. if (!gpio_is_valid(template->gpio)) {
  83. dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n",
  84. template->gpio, template->name);
  85. return 0;
  86. }
  87. if (template->active_low)
  88. flags |= GPIOF_ACTIVE_LOW;
  89. ret = devm_gpio_request_one(parent, template->gpio, flags,
  90. template->name);
  91. if (ret < 0)
  92. return ret;
  93. led_dat->gpiod = gpio_to_desc(template->gpio);
  94. if (!led_dat->gpiod)
  95. return -EINVAL;
  96. }
  97. led_dat->cdev.name = template->name;
  98. led_dat->cdev.default_trigger = template->default_trigger;
  99. led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
  100. if (!led_dat->can_sleep)
  101. led_dat->cdev.brightness_set = gpio_led_set;
  102. else
  103. led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;
  104. led_dat->blinking = 0;
  105. if (blink_set) {
  106. led_dat->platform_gpio_blink_set = blink_set;
  107. led_dat->cdev.blink_set = gpio_blink_set;
  108. }
  109. if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
  110. state = !!gpiod_get_value_cansleep(led_dat->gpiod);
  111. else
  112. state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
  113. led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
  114. if (!template->retain_state_suspended)
  115. led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
  116. if (template->panic_indicator)
  117. led_dat->cdev.flags |= LED_PANIC_INDICATOR;
  118. ret = gpiod_direction_output(led_dat->gpiod, state);
  119. if (ret < 0)
  120. return ret;
  121. return led_classdev_register(parent, &led_dat->cdev);
  122. }
  123. struct gpio_leds_priv {
  124. int num_leds;
  125. struct gpio_led_data leds[];
  126. };
  127. static inline int sizeof_gpio_leds_priv(int num_leds)
  128. {
  129. return sizeof(struct gpio_leds_priv) +
  130. (sizeof(struct gpio_led_data) * num_leds);
  131. }
  132. static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
  133. {
  134. struct device *dev = &pdev->dev;
  135. struct fwnode_handle *child;
  136. struct gpio_leds_priv *priv;
  137. int count, ret;
  138. struct device_node *np;
  139. count = device_get_child_node_count(dev);
  140. if (!count)
  141. return ERR_PTR(-ENODEV);
  142. priv = devm_kzalloc(dev, sizeof_gpio_leds_priv(count), GFP_KERNEL);
  143. if (!priv)
  144. return ERR_PTR(-ENOMEM);
  145. device_for_each_child_node(dev, child) {
  146. struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];
  147. struct gpio_led led = {};
  148. const char *state = NULL;
  149. led.gpiod = devm_get_gpiod_from_child(dev, NULL, child);
  150. if (IS_ERR(led.gpiod)) {
  151. fwnode_handle_put(child);
  152. ret = PTR_ERR(led.gpiod);
  153. goto err;
  154. }
  155. np = to_of_node(child);
  156. if (fwnode_property_present(child, "label")) {
  157. fwnode_property_read_string(child, "label", &led.name);
  158. } else {
  159. if (IS_ENABLED(CONFIG_OF) && !led.name && np)
  160. led.name = np->name;
  161. if (!led.name) {
  162. ret = -EINVAL;
  163. goto err;
  164. }
  165. }
  166. fwnode_property_read_string(child, "linux,default-trigger",
  167. &led.default_trigger);
  168. if (!fwnode_property_read_string(child, "default-state",
  169. &state)) {
  170. if (!strcmp(state, "keep"))
  171. led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
  172. else if (!strcmp(state, "on"))
  173. led.default_state = LEDS_GPIO_DEFSTATE_ON;
  174. else
  175. led.default_state = LEDS_GPIO_DEFSTATE_OFF;
  176. }
  177. if (fwnode_property_present(child, "retain-state-suspended"))
  178. led.retain_state_suspended = 1;
  179. if (fwnode_property_present(child, "panic-indicator"))
  180. led.panic_indicator = 1;
  181. ret = create_gpio_led(&led, led_dat, dev, NULL);
  182. if (ret < 0) {
  183. fwnode_handle_put(child);
  184. goto err;
  185. }
  186. led_dat->cdev.dev->of_node = np;
  187. priv->num_leds++;
  188. }
  189. return priv;
  190. err:
  191. for (count = priv->num_leds - 1; count >= 0; count--)
  192. led_classdev_unregister(&priv->leds[count].cdev);
  193. return ERR_PTR(ret);
  194. }
  195. static const struct of_device_id of_gpio_leds_match[] = {
  196. { .compatible = "gpio-leds", },
  197. {},
  198. };
  199. MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
  200. static int gpio_led_probe(struct platform_device *pdev)
  201. {
  202. struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
  203. struct gpio_leds_priv *priv;
  204. int i, ret = 0;
  205. if (pdata && pdata->num_leds) {
  206. priv = devm_kzalloc(&pdev->dev,
  207. sizeof_gpio_leds_priv(pdata->num_leds),
  208. GFP_KERNEL);
  209. if (!priv)
  210. return -ENOMEM;
  211. priv->num_leds = pdata->num_leds;
  212. for (i = 0; i < priv->num_leds; i++) {
  213. ret = create_gpio_led(&pdata->leds[i],
  214. &priv->leds[i],
  215. &pdev->dev, pdata->gpio_blink_set);
  216. if (ret < 0) {
  217. /* On failure: unwind the led creations */
  218. for (i = i - 1; i >= 0; i--)
  219. led_classdev_unregister(
  220. &priv->leds[i].cdev);
  221. return ret;
  222. }
  223. }
  224. } else {
  225. priv = gpio_leds_create(pdev);
  226. if (IS_ERR(priv))
  227. return PTR_ERR(priv);
  228. }
  229. platform_set_drvdata(pdev, priv);
  230. return 0;
  231. }
  232. static int gpio_led_remove(struct platform_device *pdev)
  233. {
  234. struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
  235. int i;
  236. for (i = 0; i < priv->num_leds; i++)
  237. led_classdev_unregister(&priv->leds[i].cdev);
  238. return 0;
  239. }
  240. static void gpio_led_shutdown(struct platform_device *pdev)
  241. {
  242. struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
  243. int i;
  244. for (i = 0; i < priv->num_leds; i++) {
  245. struct gpio_led_data *led = &priv->leds[i];
  246. gpio_led_set(&led->cdev, LED_OFF);
  247. }
  248. }
  249. static struct platform_driver gpio_led_driver = {
  250. .probe = gpio_led_probe,
  251. .remove = gpio_led_remove,
  252. .shutdown = gpio_led_shutdown,
  253. .driver = {
  254. .name = "leds-gpio",
  255. .of_match_table = of_gpio_leds_match,
  256. },
  257. };
  258. module_platform_driver(gpio_led_driver);
  259. MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
  260. MODULE_DESCRIPTION("GPIO LED driver");
  261. MODULE_LICENSE("GPL");
  262. MODULE_ALIAS("platform:leds-gpio");