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/workqueue.h>
21 struct gpio_led_data {
22 struct led_classdev cdev;
24 struct work_struct work;
28 int (*platform_gpio_blink_set)(unsigned gpio,
29 unsigned long *delay_on, unsigned long *delay_off);
32 static void gpio_led_work(struct work_struct *work)
34 struct gpio_led_data *led_dat =
35 container_of(work, struct gpio_led_data, work);
37 gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
40 static void gpio_led_set(struct led_classdev *led_cdev,
41 enum led_brightness value)
43 struct gpio_led_data *led_dat =
44 container_of(led_cdev, struct gpio_led_data, cdev);
52 if (led_dat->active_low)
55 /* Setting GPIOs with I2C/etc requires a task context, and we don't
56 * seem to have a reliable way to know if we're already in one; so
57 * let's just assume the worst.
59 if (led_dat->can_sleep) {
60 led_dat->new_level = level;
61 schedule_work(&led_dat->work);
63 gpio_set_value(led_dat->gpio, level);
66 static int gpio_blink_set(struct led_classdev *led_cdev,
67 unsigned long *delay_on, unsigned long *delay_off)
69 struct gpio_led_data *led_dat =
70 container_of(led_cdev, struct gpio_led_data, cdev);
72 return led_dat->platform_gpio_blink_set(led_dat->gpio, delay_on, delay_off);
75 static int __devinit create_gpio_led(const struct gpio_led *template,
76 struct gpio_led_data *led_dat, struct device *parent,
77 int (*blink_set)(unsigned, unsigned long *, unsigned long *))
83 /* skip leds that aren't available */
84 if (!gpio_is_valid(template->gpio)) {
85 printk(KERN_INFO "Skipping unavailable LED gpio %d (%s)\n",
86 template->gpio, template->name);
90 ret = gpio_request(template->gpio, template->name);
94 led_dat->cdev.name = template->name;
95 led_dat->cdev.default_trigger = template->default_trigger;
96 led_dat->gpio = template->gpio;
97 led_dat->can_sleep = gpio_cansleep(template->gpio);
98 led_dat->active_low = template->active_low;
100 led_dat->platform_gpio_blink_set = blink_set;
101 led_dat->cdev.blink_set = gpio_blink_set;
103 led_dat->cdev.brightness_set = gpio_led_set;
104 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
105 state = !!gpio_get_value(led_dat->gpio) ^ led_dat->active_low;
107 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
108 led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
109 if (!template->retain_state_suspended)
110 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
112 ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state);
116 INIT_WORK(&led_dat->work, gpio_led_work);
118 ret = led_classdev_register(parent, &led_dat->cdev);
124 gpio_free(led_dat->gpio);
128 static void delete_gpio_led(struct gpio_led_data *led)
130 if (!gpio_is_valid(led->gpio))
132 led_classdev_unregister(&led->cdev);
133 cancel_work_sync(&led->work);
134 gpio_free(led->gpio);
137 #ifdef CONFIG_LEDS_GPIO_PLATFORM
138 static int __devinit gpio_led_probe(struct platform_device *pdev)
140 struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
141 struct gpio_led_data *leds_data;
147 leds_data = kzalloc(sizeof(struct gpio_led_data) * pdata->num_leds,
152 for (i = 0; i < pdata->num_leds; i++) {
153 ret = create_gpio_led(&pdata->leds[i], &leds_data[i],
154 &pdev->dev, pdata->gpio_blink_set);
159 platform_set_drvdata(pdev, leds_data);
164 for (i = i - 1; i >= 0; i--)
165 delete_gpio_led(&leds_data[i]);
172 static int __devexit gpio_led_remove(struct platform_device *pdev)
175 struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
176 struct gpio_led_data *leds_data;
178 leds_data = platform_get_drvdata(pdev);
180 for (i = 0; i < pdata->num_leds; i++)
181 delete_gpio_led(&leds_data[i]);
188 static struct platform_driver gpio_led_driver = {
189 .probe = gpio_led_probe,
190 .remove = __devexit_p(gpio_led_remove),
193 .owner = THIS_MODULE,
197 MODULE_ALIAS("platform:leds-gpio");
198 #endif /* CONFIG_LEDS_GPIO_PLATFORM */
200 /* Code to create from OpenFirmware platform devices */
201 #ifdef CONFIG_LEDS_GPIO_OF
202 #include <linux/of_platform.h>
203 #include <linux/of_gpio.h>
205 struct gpio_led_of_platform_data {
207 struct gpio_led_data led_data[];
210 static int __devinit of_gpio_leds_probe(struct of_device *ofdev,
211 const struct of_device_id *match)
213 struct device_node *np = ofdev->node, *child;
215 struct gpio_led_of_platform_data *pdata;
218 /* count LEDs defined by this device, so we know how much to allocate */
219 for_each_child_of_node(np, child)
222 return 0; /* or ENODEV? */
224 pdata = kzalloc(sizeof(*pdata) + sizeof(struct gpio_led_data) * count,
229 memset(&led, 0, sizeof(led));
230 for_each_child_of_node(np, child) {
231 enum of_gpio_flags flags;
234 led.gpio = of_get_gpio_flags(child, 0, &flags);
235 led.active_low = flags & OF_GPIO_ACTIVE_LOW;
236 led.name = of_get_property(child, "label", NULL) ? : child->name;
237 led.default_trigger =
238 of_get_property(child, "linux,default-trigger", NULL);
239 state = of_get_property(child, "default-state", NULL);
241 if (!strcmp(state, "keep"))
242 led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
243 else if(!strcmp(state, "on"))
244 led.default_state = LEDS_GPIO_DEFSTATE_ON;
246 led.default_state = LEDS_GPIO_DEFSTATE_OFF;
249 ret = create_gpio_led(&led, &pdata->led_data[pdata->num_leds++],
257 dev_set_drvdata(&ofdev->dev, pdata);
262 for (count = pdata->num_leds - 2; count >= 0; count--)
263 delete_gpio_led(&pdata->led_data[count]);
270 static int __devexit of_gpio_leds_remove(struct of_device *ofdev)
272 struct gpio_led_of_platform_data *pdata = dev_get_drvdata(&ofdev->dev);
275 for (i = 0; i < pdata->num_leds; i++)
276 delete_gpio_led(&pdata->led_data[i]);
280 dev_set_drvdata(&ofdev->dev, NULL);
285 static const struct of_device_id of_gpio_leds_match[] = {
286 { .compatible = "gpio-leds", },
290 static struct of_platform_driver of_gpio_leds_driver = {
292 .name = "of_gpio_leds",
293 .owner = THIS_MODULE,
295 .match_table = of_gpio_leds_match,
296 .probe = of_gpio_leds_probe,
297 .remove = __devexit_p(of_gpio_leds_remove),
301 static int __init gpio_led_init(void)
305 #ifdef CONFIG_LEDS_GPIO_PLATFORM
306 ret = platform_driver_register(&gpio_led_driver);
310 #ifdef CONFIG_LEDS_GPIO_OF
311 ret = of_register_platform_driver(&of_gpio_leds_driver);
313 #ifdef CONFIG_LEDS_GPIO_PLATFORM
315 platform_driver_unregister(&gpio_led_driver);
321 static void __exit gpio_led_exit(void)
323 #ifdef CONFIG_LEDS_GPIO_PLATFORM
324 platform_driver_unregister(&gpio_led_driver);
326 #ifdef CONFIG_LEDS_GPIO_OF
327 of_unregister_platform_driver(&of_gpio_leds_driver);
331 module_init(gpio_led_init);
332 module_exit(gpio_led_exit);
334 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
335 MODULE_DESCRIPTION("GPIO LED driver");
336 MODULE_LICENSE("GPL");