2 * leds-regulator.c - LED class driver for regulator driven LEDs.
4 * Copyright (C) 2009 Antonio Ospite <ospite@studenti.unina.it>
6 * Inspired by leds-wm8350 driver.
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.
14 #include <linux/module.h>
15 #include <linux/err.h>
16 #include <linux/slab.h>
17 #include <linux/workqueue.h>
18 #include <linux/leds.h>
19 #include <linux/leds-regulator.h>
20 #include <linux/platform_device.h>
21 #include <linux/regulator/consumer.h>
23 #define to_regulator_led(led_cdev) \
24 container_of(led_cdev, struct regulator_led, cdev)
26 struct regulator_led {
27 struct led_classdev cdev;
28 enum led_brightness value;
31 struct work_struct work;
33 struct regulator *vcc;
36 static inline int led_regulator_get_max_brightness(struct regulator *supply)
39 int voltage = regulator_list_voltage(supply, 0);
44 /* even if regulator can't change voltages,
45 * we still assume it can change status
46 * and the LED can be turned on and off.
48 ret = regulator_set_voltage(supply, voltage, voltage);
52 return regulator_count_voltages(supply);
55 static int led_regulator_get_voltage(struct regulator *supply,
56 enum led_brightness brightness)
61 return regulator_list_voltage(supply, brightness - 1);
65 static void regulator_led_enable(struct regulator_led *led)
72 ret = regulator_enable(led->vcc);
74 dev_err(led->cdev.dev, "Failed to enable vcc: %d\n", ret);
81 static void regulator_led_disable(struct regulator_led *led)
88 ret = regulator_disable(led->vcc);
90 dev_err(led->cdev.dev, "Failed to disable vcc: %d\n", ret);
97 static void regulator_led_set_value(struct regulator_led *led)
102 mutex_lock(&led->mutex);
104 if (led->value == LED_OFF) {
105 regulator_led_disable(led);
109 if (led->cdev.max_brightness > 1) {
110 voltage = led_regulator_get_voltage(led->vcc, led->value);
111 dev_dbg(led->cdev.dev, "brightness: %d voltage: %d\n",
112 led->value, voltage);
114 ret = regulator_set_voltage(led->vcc, voltage, voltage);
116 dev_err(led->cdev.dev, "Failed to set voltage %d: %d\n",
120 regulator_led_enable(led);
123 mutex_unlock(&led->mutex);
126 static void led_work(struct work_struct *work)
128 struct regulator_led *led;
130 led = container_of(work, struct regulator_led, work);
131 regulator_led_set_value(led);
134 static void regulator_led_brightness_set(struct led_classdev *led_cdev,
135 enum led_brightness value)
137 struct regulator_led *led = to_regulator_led(led_cdev);
140 schedule_work(&led->work);
143 static int __devinit regulator_led_probe(struct platform_device *pdev)
145 struct led_regulator_platform_data *pdata = pdev->dev.platform_data;
146 struct regulator_led *led;
147 struct regulator *vcc;
151 dev_err(&pdev->dev, "no platform data\n");
155 vcc = regulator_get_exclusive(&pdev->dev, "vled");
157 dev_err(&pdev->dev, "Cannot get vcc for %s\n", pdata->name);
161 led = kzalloc(sizeof(*led), GFP_KERNEL);
167 led->cdev.max_brightness = led_regulator_get_max_brightness(vcc);
168 if (pdata->brightness > led->cdev.max_brightness) {
169 dev_err(&pdev->dev, "Invalid default brightness %d\n",
174 led->value = pdata->brightness;
176 led->cdev.brightness_set = regulator_led_brightness_set;
177 led->cdev.name = pdata->name;
178 led->cdev.flags |= LED_CORE_SUSPENDRESUME;
181 mutex_init(&led->mutex);
182 INIT_WORK(&led->work, led_work);
184 platform_set_drvdata(pdev, led);
186 ret = led_classdev_register(&pdev->dev, &led->cdev);
188 cancel_work_sync(&led->work);
192 /* to expose the default value to userspace */
193 led->cdev.brightness = led->value;
195 /* Set the default led status */
196 regulator_led_set_value(led);
207 static int __devexit regulator_led_remove(struct platform_device *pdev)
209 struct regulator_led *led = platform_get_drvdata(pdev);
211 led_classdev_unregister(&led->cdev);
212 cancel_work_sync(&led->work);
213 regulator_led_disable(led);
214 regulator_put(led->vcc);
219 static struct platform_driver regulator_led_driver = {
221 .name = "leds-regulator",
222 .owner = THIS_MODULE,
224 .probe = regulator_led_probe,
225 .remove = __devexit_p(regulator_led_remove),
228 static int __init regulator_led_init(void)
230 return platform_driver_register(®ulator_led_driver);
232 module_init(regulator_led_init);
234 static void __exit regulator_led_exit(void)
236 platform_driver_unregister(®ulator_led_driver);
238 module_exit(regulator_led_exit);
240 MODULE_AUTHOR("Antonio Ospite <ospite@studenti.unina.it>");
241 MODULE_DESCRIPTION("Regulator driven LED driver");
242 MODULE_LICENSE("GPL");
243 MODULE_ALIAS("platform:leds-regulator");