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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");