leds-wm8350.c 5.0 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * LED driver for WM8350 driven LEDS.
  4. *
  5. * Copyright(C) 2007, 2008 Wolfson Microelectronics PLC.
  6. */
  7. #include <linux/kernel.h>
  8. #include <linux/platform_device.h>
  9. #include <linux/leds.h>
  10. #include <linux/err.h>
  11. #include <linux/mfd/wm8350/pmic.h>
  12. #include <linux/regulator/consumer.h>
  13. #include <linux/slab.h>
  14. #include <linux/module.h>
  15. /* Microamps */
  16. static const int isink_cur[] = {
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  81. };
  82. #define to_wm8350_led(led_cdev) \
  83. container_of(led_cdev, struct wm8350_led, cdev)
  84. static int wm8350_led_enable(struct wm8350_led *led)
  85. {
  86. int ret = 0;
  87. if (led->enabled)
  88. return ret;
  89. ret = regulator_enable(led->isink);
  90. if (ret != 0) {
  91. dev_err(led->cdev.dev, "Failed to enable ISINK: %d\n", ret);
  92. return ret;
  93. }
  94. ret = regulator_enable(led->dcdc);
  95. if (ret != 0) {
  96. dev_err(led->cdev.dev, "Failed to enable DCDC: %d\n", ret);
  97. regulator_disable(led->isink);
  98. return ret;
  99. }
  100. led->enabled = 1;
  101. return ret;
  102. }
  103. static int wm8350_led_disable(struct wm8350_led *led)
  104. {
  105. int ret = 0;
  106. if (!led->enabled)
  107. return ret;
  108. ret = regulator_disable(led->dcdc);
  109. if (ret != 0) {
  110. dev_err(led->cdev.dev, "Failed to disable DCDC: %d\n", ret);
  111. return ret;
  112. }
  113. ret = regulator_disable(led->isink);
  114. if (ret != 0) {
  115. dev_err(led->cdev.dev, "Failed to disable ISINK: %d\n", ret);
  116. ret = regulator_enable(led->dcdc);
  117. if (ret != 0)
  118. dev_err(led->cdev.dev, "Failed to reenable DCDC: %d\n",
  119. ret);
  120. return ret;
  121. }
  122. led->enabled = 0;
  123. return ret;
  124. }
  125. static int wm8350_led_set(struct led_classdev *led_cdev,
  126. enum led_brightness value)
  127. {
  128. struct wm8350_led *led = to_wm8350_led(led_cdev);
  129. unsigned long flags;
  130. int ret;
  131. int uA;
  132. led->value = value;
  133. spin_lock_irqsave(&led->value_lock, flags);
  134. if (led->value == LED_OFF) {
  135. spin_unlock_irqrestore(&led->value_lock, flags);
  136. return wm8350_led_disable(led);
  137. }
  138. /* This scales linearly into the index of valid current
  139. * settings which results in a linear scaling of perceived
  140. * brightness due to the non-linear current settings provided
  141. * by the hardware.
  142. */
  143. uA = (led->max_uA_index * led->value) / LED_FULL;
  144. spin_unlock_irqrestore(&led->value_lock, flags);
  145. BUG_ON(uA >= ARRAY_SIZE(isink_cur));
  146. ret = regulator_set_current_limit(led->isink, isink_cur[uA],
  147. isink_cur[uA]);
  148. if (ret != 0) {
  149. dev_err(led->cdev.dev, "Failed to set %duA: %d\n",
  150. isink_cur[uA], ret);
  151. return ret;
  152. }
  153. return wm8350_led_enable(led);
  154. }
  155. static void wm8350_led_shutdown(struct platform_device *pdev)
  156. {
  157. struct wm8350_led *led = platform_get_drvdata(pdev);
  158. led->value = LED_OFF;
  159. wm8350_led_disable(led);
  160. }
  161. static int wm8350_led_probe(struct platform_device *pdev)
  162. {
  163. struct regulator *isink, *dcdc;
  164. struct wm8350_led *led;
  165. struct wm8350_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
  166. int i;
  167. if (pdata == NULL) {
  168. dev_err(&pdev->dev, "no platform data\n");
  169. return -ENODEV;
  170. }
  171. if (pdata->max_uA < isink_cur[0]) {
  172. dev_err(&pdev->dev, "Invalid maximum current %duA\n",
  173. pdata->max_uA);
  174. return -EINVAL;
  175. }
  176. isink = devm_regulator_get(&pdev->dev, "led_isink");
  177. if (IS_ERR(isink)) {
  178. dev_err(&pdev->dev, "%s: can't get ISINK\n", __func__);
  179. return PTR_ERR(isink);
  180. }
  181. dcdc = devm_regulator_get(&pdev->dev, "led_vcc");
  182. if (IS_ERR(dcdc)) {
  183. dev_err(&pdev->dev, "%s: can't get DCDC\n", __func__);
  184. return PTR_ERR(dcdc);
  185. }
  186. led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
  187. if (led == NULL)
  188. return -ENOMEM;
  189. led->cdev.brightness_set_blocking = wm8350_led_set;
  190. led->cdev.default_trigger = pdata->default_trigger;
  191. led->cdev.name = pdata->name;
  192. led->cdev.flags |= LED_CORE_SUSPENDRESUME;
  193. led->enabled = regulator_is_enabled(isink);
  194. led->isink = isink;
  195. led->dcdc = dcdc;
  196. for (i = 0; i < ARRAY_SIZE(isink_cur) - 1; i++)
  197. if (isink_cur[i] >= pdata->max_uA)
  198. break;
  199. led->max_uA_index = i;
  200. if (pdata->max_uA != isink_cur[i])
  201. dev_warn(&pdev->dev,
  202. "Maximum current %duA is not directly supported,"
  203. " check platform data\n",
  204. pdata->max_uA);
  205. spin_lock_init(&led->value_lock);
  206. led->value = LED_OFF;
  207. platform_set_drvdata(pdev, led);
  208. return led_classdev_register(&pdev->dev, &led->cdev);
  209. }
  210. static int wm8350_led_remove(struct platform_device *pdev)
  211. {
  212. struct wm8350_led *led = platform_get_drvdata(pdev);
  213. led_classdev_unregister(&led->cdev);
  214. wm8350_led_disable(led);
  215. return 0;
  216. }
  217. static struct platform_driver wm8350_led_driver = {
  218. .driver = {
  219. .name = "wm8350-led",
  220. },
  221. .probe = wm8350_led_probe,
  222. .remove = wm8350_led_remove,
  223. .shutdown = wm8350_led_shutdown,
  224. };
  225. module_platform_driver(wm8350_led_driver);
  226. MODULE_AUTHOR("Mark Brown");
  227. MODULE_DESCRIPTION("WM8350 LED driver");
  228. MODULE_LICENSE("GPL");
  229. MODULE_ALIAS("platform:wm8350-led");