/*
   * Bachmann ot200 leds driver.
   *
   * Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
   *         Christian Gmeiner <christian.gmeiner@gmail.com>
   *
   * License: GPL as published by the FSF.
   */
  
  #include <linux/kernel.h>

  #include <linux/platform_device.h>
  #include <linux/slab.h>
  #include <linux/leds.h>
  #include <linux/io.h>
  #include <linux/module.h>
  
  
  struct ot200_led {
  	struct led_classdev cdev;
  	const char *name;
  	unsigned long port;
  	u8 mask;
  };
  
  /*
   * The device has three leds on the back panel (led_err, led_init and led_run)
   * and can handle up to seven leds on the front panel.
   */
  
  static struct ot200_led leds[] = {
  	{
  		.name = "led_run",
  		.port = 0x5a,
  		.mask = BIT(0),
  	},
  	{
  		.name = "led_init",
  		.port = 0x5a,
  		.mask = BIT(1),
  	},
  	{
  		.name = "led_err",
  		.port = 0x5a,
  		.mask = BIT(2),
  	},
  	{
  		.name = "led_1",
  		.port = 0x49,

  		.mask = BIT(6),

  	},
  	{
  		.name = "led_2",
  		.port = 0x49,

  		.mask = BIT(5),

  	},
  	{
  		.name = "led_3",
  		.port = 0x49,

  		.mask = BIT(4),

  	},
  	{
  		.name = "led_4",
  		.port = 0x49,

  		.mask = BIT(3),

  	},
  	{
  		.name = "led_5",
  		.port = 0x49,

  		.mask = BIT(2),

  	},
  	{
  		.name = "led_6",
  		.port = 0x49,

  		.mask = BIT(1),

  	},
  	{
  		.name = "led_7",
  		.port = 0x49,

  		.mask = BIT(0),

  	}
  };
  
  static DEFINE_SPINLOCK(value_lock);
  
  /*
   * we need to store the current led states, as it is not
   * possible to read the current led state via inb().
   */
  static u8 leds_back;
  static u8 leds_front;
  
  static void ot200_led_brightness_set(struct led_classdev *led_cdev,
  		enum led_brightness value)
  {
  	struct ot200_led *led = container_of(led_cdev, struct ot200_led, cdev);
  	u8 *val;
  	unsigned long flags;
  
  	spin_lock_irqsave(&value_lock, flags);
  
  	if (led->port == 0x49)
  		val = &leds_front;
  	else if (led->port == 0x5a)
  		val = &leds_back;
  	else
  		BUG();
  
  	if (value == LED_OFF)
  		*val &= ~led->mask;
  	else
  		*val |= led->mask;
  
  	outb(*val, led->port);
  	spin_unlock_irqrestore(&value_lock, flags);
  }

  static int ot200_led_probe(struct platform_device *pdev)

  {
  	int i;
  	int ret;
  
  	for (i = 0; i < ARRAY_SIZE(leds); i++) {
  
  		leds[i].cdev.name = leds[i].name;
  		leds[i].cdev.brightness_set = ot200_led_brightness_set;

  		ret = devm_led_classdev_register(&pdev->dev, &leds[i].cdev);

  		if (ret < 0)

  			return ret;

  	}
  
  	leds_front = 0;		/* turn off all front leds */
  	leds_back = BIT(1);	/* turn on init led */
  	outb(leds_front, 0x49);
  	outb(leds_back, 0x5a);
  
  	return 0;

  }
  
  static struct platform_driver ot200_led_driver = {
  	.probe		= ot200_led_probe,

  	.driver		= {
  		.name	= "leds-ot200",

  	},
  };
  
  module_platform_driver(ot200_led_driver);
  
  MODULE_AUTHOR("Sebastian A. Siewior <bigeasy@linutronix.de>");
  MODULE_DESCRIPTION("ot200 LED driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:leds-ot200");