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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 = cur_led->active_low ? LED_FULL : 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");