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/*
* LEDs driver for GPIOs
*
* Copyright (C) 2007 8D Technologies inc.
* Raphael Assenat <raph@8d.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <linux/workqueue.h>
#include <asm/gpio.h>
struct gpio_led_data {
struct led_classdev cdev;
unsigned gpio;
struct work_struct work;
u8 new_level;
u8 can_sleep;
u8 active_low;
};
static void gpio_led_work(struct work_struct *work)
{
struct gpio_led_data *led_dat =
container_of(work, struct gpio_led_data, work);
gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
}
static void gpio_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct gpio_led_data *led_dat =
container_of(led_cdev, struct gpio_led_data, cdev);
int level;
if (value == LED_OFF)
level = 0;
else
level = 1;
if (led_dat->active_low)
level = !level;
/* setting GPIOs with I2C/etc requires a preemptible task context */
if (led_dat->can_sleep) {
if (preempt_count()) {
led_dat->new_level = level;
schedule_work(&led_dat->work);
} else
gpio_set_value_cansleep(led_dat->gpio, level);
} else
gpio_set_value(led_dat->gpio, level);
}
static int gpio_led_probe(struct platform_device *pdev)
{
struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
struct gpio_led *cur_led;
struct gpio_led_data *leds_data, *led_dat;
int i, ret = 0;
if (!pdata)
return -EBUSY;
leds_data = kzalloc(sizeof(struct gpio_led_data) * pdata->num_leds,
GFP_KERNEL);
if (!leds_data)
return -ENOMEM;
for (i = 0; i < pdata->num_leds; i++) {
cur_led = &pdata->leds[i];
led_dat = &leds_data[i];
led_dat->cdev.name = cur_led->name;
led_dat->cdev.default_trigger = cur_led->default_trigger;
led_dat->gpio = cur_led->gpio;
led_dat->can_sleep = gpio_cansleep(cur_led->gpio);
led_dat->active_low = cur_led->active_low;
led_dat->cdev.brightness_set = gpio_led_set;
led_dat->cdev.brightness = LED_OFF;
ret = gpio_request(led_dat->gpio, led_dat->cdev.name);
if (ret < 0)
goto err;
gpio_direction_output(led_dat->gpio, led_dat->active_low);
INIT_WORK(&led_dat->work, gpio_led_work);
ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
if (ret < 0) {
gpio_free(led_dat->gpio);
goto err;
}
}
platform_set_drvdata(pdev, leds_data);
return 0;
err:
if (i > 0) {
for (i = i - 1; i >= 0; i--) {
led_classdev_unregister(&leds_data[i].cdev);
cancel_work_sync(&leds_data[i].work);
gpio_free(leds_data[i].gpio);
}
}
kfree(leds_data);
return ret;
}
static int __devexit gpio_led_remove(struct platform_device *pdev)
{
int i;
struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
struct gpio_led_data *leds_data;
leds_data = platform_get_drvdata(pdev);
for (i = 0; i < pdata->num_leds; i++) {
led_classdev_unregister(&leds_data[i].cdev);
cancel_work_sync(&leds_data[i].work);
gpio_free(leds_data[i].gpio);
}
kfree(leds_data);
return 0;
}
#ifdef CONFIG_PM
static int gpio_led_suspend(struct platform_device *pdev, pm_message_t state)
{
struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
struct gpio_led_data *leds_data;
int i;
leds_data = platform_get_drvdata(pdev);
for (i = 0; i < pdata->num_leds; i++)
led_classdev_suspend(&leds_data[i].cdev);
return 0;
}
static int gpio_led_resume(struct platform_device *pdev)
{
struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
struct gpio_led_data *leds_data;
int i;
leds_data = platform_get_drvdata(pdev);
for (i = 0; i < pdata->num_leds; i++)
led_classdev_resume(&leds_data[i].cdev);
return 0;
}
#else
#define gpio_led_suspend NULL
#define gpio_led_resume NULL
#endif
static struct platform_driver gpio_led_driver = {
.probe = gpio_led_probe,
.remove = __devexit_p(gpio_led_remove),
.suspend = gpio_led_suspend,
.resume = gpio_led_resume,
.driver = {
.name = "leds-gpio",
.owner = THIS_MODULE,
},
};
static int __init gpio_led_init(void)
{
return platform_driver_register(&gpio_led_driver);
}
static void __exit gpio_led_exit(void)
{
platform_driver_unregister(&gpio_led_driver);
}
module_init(gpio_led_init);
module_exit(gpio_led_exit);
MODULE_AUTHOR("Raphael Assenat <raph@8d.com>");
MODULE_DESCRIPTION("GPIO LED driver");
MODULE_LICENSE("GPL");
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