leds-wm8350.c 6.3 KB

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  1. /*
  2. * LED driver for WM8350 driven LEDS.
  3. *
  4. * Copyright(C) 2007, 2008 Wolfson Microelectronics PLC.
  5. *
  6. * This program is free software; you can redistribute it and/or modify
  7. * it under the terms of the GNU General Public License version 2 as
  8. * published by the Free Software Foundation.
  9. *
  10. */
  11. #include <linux/kernel.h>
  12. #include <linux/init.h>
  13. #include <linux/platform_device.h>
  14. #include <linux/leds.h>
  15. #include <linux/err.h>
  16. #include <linux/mfd/wm8350/pmic.h>
  17. #include <linux/regulator/consumer.h>
  18. /* Microamps */
  19. static const int isink_cur[] = {
  20. 4,
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  84. };
  85. #define to_wm8350_led(led_cdev) \
  86. container_of(led_cdev, struct wm8350_led, cdev)
  87. static void wm8350_led_enable(struct wm8350_led *led)
  88. {
  89. int ret;
  90. if (led->enabled)
  91. return;
  92. ret = regulator_enable(led->isink);
  93. if (ret != 0) {
  94. dev_err(led->cdev.dev, "Failed to enable ISINK: %d\n", ret);
  95. return;
  96. }
  97. ret = regulator_enable(led->dcdc);
  98. if (ret != 0) {
  99. dev_err(led->cdev.dev, "Failed to enable DCDC: %d\n", ret);
  100. regulator_disable(led->isink);
  101. return;
  102. }
  103. led->enabled = 1;
  104. }
  105. static void wm8350_led_disable(struct wm8350_led *led)
  106. {
  107. int ret;
  108. if (!led->enabled)
  109. return;
  110. ret = regulator_disable(led->dcdc);
  111. if (ret != 0) {
  112. dev_err(led->cdev.dev, "Failed to disable DCDC: %d\n", ret);
  113. return;
  114. }
  115. ret = regulator_disable(led->isink);
  116. if (ret != 0) {
  117. dev_err(led->cdev.dev, "Failed to disable ISINK: %d\n", ret);
  118. regulator_enable(led->dcdc);
  119. return;
  120. }
  121. led->enabled = 0;
  122. }
  123. static void led_work(struct work_struct *work)
  124. {
  125. struct wm8350_led *led = container_of(work, struct wm8350_led, work);
  126. int ret;
  127. int uA;
  128. unsigned long flags;
  129. mutex_lock(&led->mutex);
  130. spin_lock_irqsave(&led->value_lock, flags);
  131. if (led->value == LED_OFF) {
  132. spin_unlock_irqrestore(&led->value_lock, flags);
  133. wm8350_led_disable(led);
  134. goto out;
  135. }
  136. /* This scales linearly into the index of valid current
  137. * settings which results in a linear scaling of perceived
  138. * brightness due to the non-linear current settings provided
  139. * by the hardware.
  140. */
  141. uA = (led->max_uA_index * led->value) / LED_FULL;
  142. spin_unlock_irqrestore(&led->value_lock, flags);
  143. BUG_ON(uA >= ARRAY_SIZE(isink_cur));
  144. ret = regulator_set_current_limit(led->isink, isink_cur[uA],
  145. isink_cur[uA]);
  146. if (ret != 0)
  147. dev_err(led->cdev.dev, "Failed to set %duA: %d\n",
  148. isink_cur[uA], ret);
  149. wm8350_led_enable(led);
  150. out:
  151. mutex_unlock(&led->mutex);
  152. }
  153. static void wm8350_led_set(struct led_classdev *led_cdev,
  154. enum led_brightness value)
  155. {
  156. struct wm8350_led *led = to_wm8350_led(led_cdev);
  157. unsigned long flags;
  158. spin_lock_irqsave(&led->value_lock, flags);
  159. led->value = value;
  160. schedule_work(&led->work);
  161. spin_unlock_irqrestore(&led->value_lock, flags);
  162. }
  163. #ifdef CONFIG_PM
  164. static int wm8350_led_suspend(struct platform_device *pdev, pm_message_t state)
  165. {
  166. struct wm8350_led *led = platform_get_drvdata(pdev);
  167. led_classdev_suspend(&led->cdev);
  168. return 0;
  169. }
  170. static int wm8350_led_resume(struct platform_device *pdev)
  171. {
  172. struct wm8350_led *led = platform_get_drvdata(pdev);
  173. led_classdev_resume(&led->cdev);
  174. return 0;
  175. }
  176. #else
  177. #define wm8350_led_suspend NULL
  178. #define wm8350_led_resume NULL
  179. #endif
  180. static void wm8350_led_shutdown(struct platform_device *pdev)
  181. {
  182. struct wm8350_led *led = platform_get_drvdata(pdev);
  183. mutex_lock(&led->mutex);
  184. led->value = LED_OFF;
  185. wm8350_led_disable(led);
  186. mutex_unlock(&led->mutex);
  187. }
  188. static int wm8350_led_probe(struct platform_device *pdev)
  189. {
  190. struct regulator *isink, *dcdc;
  191. struct wm8350_led *led;
  192. struct wm8350_led_platform_data *pdata = pdev->dev.platform_data;
  193. int ret, i;
  194. if (pdata == NULL) {
  195. dev_err(&pdev->dev, "no platform data\n");
  196. return -ENODEV;
  197. }
  198. if (pdata->max_uA < isink_cur[0]) {
  199. dev_err(&pdev->dev, "Invalid maximum current %duA\n",
  200. pdata->max_uA);
  201. return -EINVAL;
  202. }
  203. isink = regulator_get(&pdev->dev, "led_isink");
  204. if (IS_ERR(isink)) {
  205. printk(KERN_ERR "%s: cant get ISINK\n", __func__);
  206. return PTR_ERR(isink);
  207. }
  208. dcdc = regulator_get(&pdev->dev, "led_vcc");
  209. if (IS_ERR(dcdc)) {
  210. printk(KERN_ERR "%s: cant get DCDC\n", __func__);
  211. ret = PTR_ERR(dcdc);
  212. goto err_isink;
  213. }
  214. led = kzalloc(sizeof(*led), GFP_KERNEL);
  215. if (led == NULL) {
  216. ret = -ENOMEM;
  217. goto err_dcdc;
  218. }
  219. led->cdev.brightness_set = wm8350_led_set;
  220. led->cdev.default_trigger = pdata->default_trigger;
  221. led->cdev.name = pdata->name;
  222. led->enabled = regulator_is_enabled(isink);
  223. led->isink = isink;
  224. led->dcdc = dcdc;
  225. for (i = 0; i < ARRAY_SIZE(isink_cur) - 1; i++)
  226. if (isink_cur[i] >= pdata->max_uA)
  227. break;
  228. led->max_uA_index = i;
  229. if (pdata->max_uA != isink_cur[i])
  230. dev_warn(&pdev->dev,
  231. "Maximum current %duA is not directly supported,"
  232. " check platform data\n",
  233. pdata->max_uA);
  234. spin_lock_init(&led->value_lock);
  235. mutex_init(&led->mutex);
  236. INIT_WORK(&led->work, led_work);
  237. led->value = LED_OFF;
  238. platform_set_drvdata(pdev, led);
  239. ret = led_classdev_register(&pdev->dev, &led->cdev);
  240. if (ret < 0)
  241. goto err_led;
  242. return 0;
  243. err_led:
  244. kfree(led);
  245. err_dcdc:
  246. regulator_put(dcdc);
  247. err_isink:
  248. regulator_put(isink);
  249. return ret;
  250. }
  251. static int wm8350_led_remove(struct platform_device *pdev)
  252. {
  253. struct wm8350_led *led = platform_get_drvdata(pdev);
  254. led_classdev_unregister(&led->cdev);
  255. flush_scheduled_work();
  256. wm8350_led_disable(led);
  257. regulator_put(led->dcdc);
  258. regulator_put(led->isink);
  259. kfree(led);
  260. return 0;
  261. }
  262. static struct platform_driver wm8350_led_driver = {
  263. .driver = {
  264. .name = "wm8350-led",
  265. .owner = THIS_MODULE,
  266. },
  267. .probe = wm8350_led_probe,
  268. .remove = wm8350_led_remove,
  269. .shutdown = wm8350_led_shutdown,
  270. .suspend = wm8350_led_suspend,
  271. .resume = wm8350_led_resume,
  272. };
  273. static int __devinit wm8350_led_init(void)
  274. {
  275. return platform_driver_register(&wm8350_led_driver);
  276. }
  277. module_init(wm8350_led_init);
  278. static void wm8350_led_exit(void)
  279. {
  280. platform_driver_unregister(&wm8350_led_driver);
  281. }
  282. module_exit(wm8350_led_exit);
  283. MODULE_AUTHOR("Mark Brown");
  284. MODULE_DESCRIPTION("WM8350 LED driver");
  285. MODULE_LICENSE("GPL");
  286. MODULE_ALIAS("platform:wm8350-led");