Add a 00-INDEX file to Documentation/sysctl/
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / leds / leds-gpio.c
blob47d90db280ceb5a2485e34dcc18c3cf3c704cd02
1 /*
2 * LEDs driver for GPIOs
4 * Copyright (C) 2007 8D Technologies inc.
5 * Raphael Assenat <raph@8d.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/platform_device.h>
15 #include <linux/leds.h>
16 #include <linux/workqueue.h>
18 #include <asm/gpio.h>
20 struct gpio_led_data {
21 struct led_classdev cdev;
22 unsigned gpio;
23 struct work_struct work;
24 u8 new_level;
25 u8 can_sleep;
26 u8 active_low;
29 static void gpio_led_work(struct work_struct *work)
31 struct gpio_led_data *led_dat =
32 container_of(work, struct gpio_led_data, work);
34 gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
37 static void gpio_led_set(struct led_classdev *led_cdev,
38 enum led_brightness value)
40 struct gpio_led_data *led_dat =
41 container_of(led_cdev, struct gpio_led_data, cdev);
42 int level;
44 if (value == LED_OFF)
45 level = 0;
46 else
47 level = 1;
49 if (led_dat->active_low)
50 level = !level;
52 /* setting GPIOs with I2C/etc requires a preemptible task context */
53 if (led_dat->can_sleep) {
54 if (preempt_count()) {
55 led_dat->new_level = level;
56 schedule_work(&led_dat->work);
57 } else
58 gpio_set_value_cansleep(led_dat->gpio, level);
59 } else
60 gpio_set_value(led_dat->gpio, level);
63 static int __init gpio_led_probe(struct platform_device *pdev)
65 struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
66 struct gpio_led *cur_led;
67 struct gpio_led_data *leds_data, *led_dat;
68 int i, ret = 0;
70 if (!pdata)
71 return -EBUSY;
73 leds_data = kzalloc(sizeof(struct gpio_led_data) * pdata->num_leds,
74 GFP_KERNEL);
75 if (!leds_data)
76 return -ENOMEM;
78 for (i = 0; i < pdata->num_leds; i++) {
79 cur_led = &pdata->leds[i];
80 led_dat = &leds_data[i];
82 led_dat->cdev.name = cur_led->name;
83 led_dat->cdev.default_trigger = cur_led->default_trigger;
84 led_dat->gpio = cur_led->gpio;
85 led_dat->can_sleep = gpio_cansleep(cur_led->gpio);
86 led_dat->active_low = cur_led->active_low;
87 led_dat->cdev.brightness_set = gpio_led_set;
88 led_dat->cdev.brightness = cur_led->active_low ? LED_FULL : LED_OFF;
90 ret = gpio_request(led_dat->gpio, led_dat->cdev.name);
91 if (ret < 0)
92 goto err;
94 gpio_direction_output(led_dat->gpio, led_dat->active_low);
96 ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
97 if (ret < 0) {
98 gpio_free(led_dat->gpio);
99 goto err;
102 INIT_WORK(&led_dat->work, gpio_led_work);
105 platform_set_drvdata(pdev, leds_data);
107 return 0;
109 err:
110 if (i > 0) {
111 for (i = i - 1; i >= 0; i--) {
112 led_classdev_unregister(&leds_data[i].cdev);
113 gpio_free(leds_data[i].gpio);
117 flush_scheduled_work();
118 kfree(leds_data);
120 return ret;
123 static int __exit gpio_led_remove(struct platform_device *pdev)
125 int i;
126 struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
127 struct gpio_led_data *leds_data;
129 leds_data = platform_get_drvdata(pdev);
131 for (i = 0; i < pdata->num_leds; i++) {
132 led_classdev_unregister(&leds_data[i].cdev);
133 gpio_free(leds_data[i].gpio);
136 kfree(leds_data);
138 return 0;
141 #ifdef CONFIG_PM
142 static int gpio_led_suspend(struct platform_device *pdev, pm_message_t state)
144 struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
145 struct gpio_led_data *leds_data;
146 int i;
148 leds_data = platform_get_drvdata(pdev);
150 for (i = 0; i < pdata->num_leds; i++)
151 led_classdev_suspend(&leds_data[i].cdev);
153 return 0;
156 static int gpio_led_resume(struct platform_device *pdev)
158 struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
159 struct gpio_led_data *leds_data;
160 int i;
162 leds_data = platform_get_drvdata(pdev);
164 for (i = 0; i < pdata->num_leds; i++)
165 led_classdev_resume(&leds_data[i].cdev);
167 return 0;
169 #else
170 #define gpio_led_suspend NULL
171 #define gpio_led_resume NULL
172 #endif
174 static struct platform_driver gpio_led_driver = {
175 .remove = __exit_p(gpio_led_remove),
176 .suspend = gpio_led_suspend,
177 .resume = gpio_led_resume,
178 .driver = {
179 .name = "leds-gpio",
180 .owner = THIS_MODULE,
184 static int __init gpio_led_init(void)
186 return platform_driver_probe(&gpio_led_driver, gpio_led_probe);
189 static void __exit gpio_led_exit(void)
191 platform_driver_unregister(&gpio_led_driver);
194 module_init(gpio_led_init);
195 module_exit(gpio_led_exit);
197 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>");
198 MODULE_DESCRIPTION("GPIO LED driver");
199 MODULE_LICENSE("GPL");