2 * LEDs driver for GPIOs
4 * Copyright (C) 2007 8D Technologies inc.
5 * Raphael Assenat <raph@8d.com>
6 * Copyright (C) 2008 Freescale Semiconductor, Inc.
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.
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/platform_device.h>
16 #include <linux/leds.h>
17 #include <linux/of_platform.h>
18 #include <linux/of_gpio.h>
19 #include <linux/slab.h>
20 #include <linux/workqueue.h>
24 struct gpio_led_data {
25 struct led_classdev cdev;
27 struct work_struct work;
32 int (*platform_gpio_blink_set)(unsigned gpio, int state,
33 unsigned long *delay_on, unsigned long *delay_off);
36 static void gpio_led_work(struct work_struct *work)
38 struct gpio_led_data *led_dat =
39 container_of(work, struct gpio_led_data, work);
41 if (led_dat->blinking) {
42 led_dat->platform_gpio_blink_set(led_dat->gpio,
45 led_dat->blinking = 0;
47 gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
50 static void gpio_led_set(struct led_classdev *led_cdev,
51 enum led_brightness value)
53 struct gpio_led_data *led_dat =
54 container_of(led_cdev, struct gpio_led_data, cdev);
62 if (led_dat->active_low)
65 /* Setting GPIOs with I2C/etc requires a task context, and we don't
66 * seem to have a reliable way to know if we're already in one; so
67 * let's just assume the worst.
69 if (led_dat->can_sleep) {
70 led_dat->new_level = level;
71 schedule_work(&led_dat->work);
73 if (led_dat->blinking) {
74 led_dat->platform_gpio_blink_set(led_dat->gpio, level,
76 led_dat->blinking = 0;
78 gpio_set_value(led_dat->gpio, level);
82 static int gpio_blink_set(struct led_classdev *led_cdev,
83 unsigned long *delay_on, unsigned long *delay_off)
85 struct gpio_led_data *led_dat =
86 container_of(led_cdev, struct gpio_led_data, cdev);
88 led_dat->blinking = 1;
89 return led_dat->platform_gpio_blink_set(led_dat->gpio, GPIO_LED_BLINK,
93 static int __devinit create_gpio_led(const struct gpio_led *template,
94 struct gpio_led_data *led_dat, struct device *parent,
95 int (*blink_set)(unsigned, int, unsigned long *, unsigned long *))
101 /* skip leds that aren't available */
102 if (!gpio_is_valid(template->gpio)) {
103 printk(KERN_INFO "Skipping unavailable LED gpio %d (%s)\n",
104 template->gpio, template->name);
108 ret = gpio_request(template->gpio, template->name);
112 led_dat->cdev.name = template->name;
113 led_dat->cdev.default_trigger = template->default_trigger;
114 led_dat->gpio = template->gpio;
115 led_dat->can_sleep = gpio_cansleep(template->gpio);
116 led_dat->active_low = template->active_low;
117 led_dat->blinking = 0;
119 led_dat->platform_gpio_blink_set = blink_set;
120 led_dat->cdev.blink_set = gpio_blink_set;
122 led_dat->cdev.brightness_set = gpio_led_set;
123 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
124 state = !!gpio_get_value(led_dat->gpio) ^ led_dat->active_low;
126 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
127 led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
128 if (!template->retain_state_suspended)
129 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
131 ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state);
135 INIT_WORK(&led_dat->work, gpio_led_work);
137 ret = led_classdev_register(parent, &led_dat->cdev);
143 gpio_free(led_dat->gpio);
147 static void delete_gpio_led(struct gpio_led_data *led)
149 if (!gpio_is_valid(led->gpio))
151 led_classdev_unregister(&led->cdev);
152 cancel_work_sync(&led->work);
153 gpio_free(led->gpio);
156 struct gpio_leds_priv {
158 struct gpio_led_data leds[];
161 static inline int sizeof_gpio_leds_priv(int num_leds)
163 return sizeof(struct gpio_leds_priv) +
164 (sizeof(struct gpio_led_data) * num_leds);
167 /* Code to create from OpenFirmware platform devices */
168 #ifdef CONFIG_OF_GPIO
169 static struct gpio_leds_priv * __devinit gpio_leds_create_of(struct platform_device *pdev)
171 struct device_node *np = pdev->dev.of_node, *child;
172 struct gpio_leds_priv *priv;
175 /* count LEDs in this device, so we know how much to allocate */
176 for_each_child_of_node(np, child)
181 priv = kzalloc(sizeof_gpio_leds_priv(count), GFP_KERNEL);
185 for_each_child_of_node(np, child) {
186 struct gpio_led led = {};
187 enum of_gpio_flags flags;
190 led.gpio = of_get_gpio_flags(child, 0, &flags);
191 led.active_low = flags & OF_GPIO_ACTIVE_LOW;
192 led.name = of_get_property(child, "label", NULL) ? : child->name;
193 led.default_trigger =
194 of_get_property(child, "linux,default-trigger", NULL);
195 state = of_get_property(child, "default-state", NULL);
197 if (!strcmp(state, "keep"))
198 led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
199 else if (!strcmp(state, "on"))
200 led.default_state = LEDS_GPIO_DEFSTATE_ON;
202 led.default_state = LEDS_GPIO_DEFSTATE_OFF;
205 ret = create_gpio_led(&led, &priv->leds[priv->num_leds++],
216 for (count = priv->num_leds - 2; count >= 0; count--)
217 delete_gpio_led(&priv->leds[count]);
222 static const struct of_device_id of_gpio_leds_match[] = {
223 { .compatible = "gpio-leds", },
226 #else /* CONFIG_OF_GPIO */
227 static struct gpio_leds_priv * __devinit gpio_leds_create_of(struct platform_device *pdev)
231 #define of_gpio_leds_match NULL
232 #endif /* CONFIG_OF_GPIO */
235 static int __devinit gpio_led_probe(struct platform_device *pdev)
237 struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
238 struct gpio_leds_priv *priv;
241 if (pdata && pdata->num_leds) {
242 priv = kzalloc(sizeof_gpio_leds_priv(pdata->num_leds),
247 priv->num_leds = pdata->num_leds;
248 for (i = 0; i < priv->num_leds; i++) {
249 ret = create_gpio_led(&pdata->leds[i],
251 &pdev->dev, pdata->gpio_blink_set);
253 /* On failure: unwind the led creations */
254 for (i = i - 1; i >= 0; i--)
255 delete_gpio_led(&priv->leds[i]);
261 priv = gpio_leds_create_of(pdev);
266 platform_set_drvdata(pdev, priv);
271 static int __devexit gpio_led_remove(struct platform_device *pdev)
273 struct gpio_leds_priv *priv = dev_get_drvdata(&pdev->dev);
276 for (i = 0; i < priv->num_leds; i++)
277 delete_gpio_led(&priv->leds[i]);
279 dev_set_drvdata(&pdev->dev, NULL);
285 static struct platform_driver gpio_led_driver = {
286 .probe = gpio_led_probe,
287 .remove = __devexit_p(gpio_led_remove),
290 .owner = THIS_MODULE,
291 .of_match_table = of_gpio_leds_match,
295 MODULE_ALIAS("platform:leds-gpio");
297 static int __init gpio_led_init(void)
299 return platform_driver_register(&gpio_led_driver);
302 static void __exit gpio_led_exit(void)
304 platform_driver_unregister(&gpio_led_driver);
307 module_init(gpio_led_init);
308 module_exit(gpio_led_exit);
310 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
311 MODULE_DESCRIPTION("GPIO LED driver");
312 MODULE_LICENSE("GPL");