/*
   * LED driver for WM8350 driven LEDS.
   *
   * Copyright(C) 2007, 2008 Wolfson Microelectronics PLC.
   *
   * 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/err.h>
  #include <linux/mfd/wm8350/pmic.h>
  #include <linux/regulator/consumer.h>

  #include <linux/slab.h>

  #include <linux/module.h>

  
  /* Microamps */
  static const int isink_cur[] = {
  	4,
  	5,
  	6,
  	7,
  	8,
  	10,
  	11,
  	14,
  	16,
  	19,
  	23,
  	27,
  	32,
  	39,
  	46,
  	54,
  	65,
  	77,
  	92,
  	109,
  	130,
  	154,
  	183,
  	218,
  	259,
  	308,
  	367,
  	436,
  	518,
  	616,
  	733,
  	872,
  	1037,
  	1233,
  	1466,
  	1744,
  	2073,
  	2466,
  	2933,
  	3487,
  	4147,
  	4932,
  	5865,
  	6975,
  	8294,
  	9864,
  	11730,
  	13949,
  	16589,
  	19728,
  	23460,
  	27899,
  	33178,
  	39455,
  	46920,
  	55798,
  	66355,
  	78910,
  	93840,
  	111596,
  	132710,
  	157820,
  	187681,
  	223191
  };
  
  #define to_wm8350_led(led_cdev) \
  	container_of(led_cdev, struct wm8350_led, cdev)
  
  static void wm8350_led_enable(struct wm8350_led *led)
  {
  	int ret;
  
  	if (led->enabled)
  		return;
  
  	ret = regulator_enable(led->isink);
  	if (ret != 0) {
  		dev_err(led->cdev.dev, "Failed to enable ISINK: %d
  ", ret);
  		return;
  	}
  
  	ret = regulator_enable(led->dcdc);
  	if (ret != 0) {
  		dev_err(led->cdev.dev, "Failed to enable DCDC: %d
  ", ret);
  		regulator_disable(led->isink);
  		return;
  	}
  
  	led->enabled = 1;
  }
  
  static void wm8350_led_disable(struct wm8350_led *led)
  {
  	int ret;
  
  	if (!led->enabled)
  		return;
  
  	ret = regulator_disable(led->dcdc);
  	if (ret != 0) {
  		dev_err(led->cdev.dev, "Failed to disable DCDC: %d
  ", ret);
  		return;
  	}
  
  	ret = regulator_disable(led->isink);
  	if (ret != 0) {
  		dev_err(led->cdev.dev, "Failed to disable ISINK: %d
  ", ret);
  		regulator_enable(led->dcdc);
  		return;
  	}
  
  	led->enabled = 0;
  }
  
  static void led_work(struct work_struct *work)
  {
  	struct wm8350_led *led = container_of(work, struct wm8350_led, work);
  	int ret;
  	int uA;
  	unsigned long flags;
  
  	mutex_lock(&led->mutex);
  
  	spin_lock_irqsave(&led->value_lock, flags);
  
  	if (led->value == LED_OFF) {
  		spin_unlock_irqrestore(&led->value_lock, flags);
  		wm8350_led_disable(led);
  		goto out;
  	}
  
  	/* This scales linearly into the index of valid current
  	 * settings which results in a linear scaling of perceived
  	 * brightness due to the non-linear current settings provided
  	 * by the hardware.
  	 */
  	uA = (led->max_uA_index * led->value) / LED_FULL;
  	spin_unlock_irqrestore(&led->value_lock, flags);
  	BUG_ON(uA >= ARRAY_SIZE(isink_cur));
  
  	ret = regulator_set_current_limit(led->isink, isink_cur[uA],
  					  isink_cur[uA]);
  	if (ret != 0)
  		dev_err(led->cdev.dev, "Failed to set %duA: %d
  ",
  			isink_cur[uA], ret);
  
  	wm8350_led_enable(led);
  
  out:
  	mutex_unlock(&led->mutex);
  }
  
  static void wm8350_led_set(struct led_classdev *led_cdev,
  			   enum led_brightness value)
  {
  	struct wm8350_led *led = to_wm8350_led(led_cdev);
  	unsigned long flags;
  
  	spin_lock_irqsave(&led->value_lock, flags);
  	led->value = value;
  	schedule_work(&led->work);
  	spin_unlock_irqrestore(&led->value_lock, flags);
  }

  static void wm8350_led_shutdown(struct platform_device *pdev)
  {
  	struct wm8350_led *led = platform_get_drvdata(pdev);
  
  	mutex_lock(&led->mutex);
  	led->value = LED_OFF;
  	wm8350_led_disable(led);
  	mutex_unlock(&led->mutex);
  }
  
  static int wm8350_led_probe(struct platform_device *pdev)
  {
  	struct regulator *isink, *dcdc;
  	struct wm8350_led *led;
  	struct wm8350_led_platform_data *pdata = pdev->dev.platform_data;
  	int ret, i;
  
  	if (pdata == NULL) {
  		dev_err(&pdev->dev, "no platform data
  ");
  		return -ENODEV;
  	}
  
  	if (pdata->max_uA < isink_cur[0]) {
  		dev_err(&pdev->dev, "Invalid maximum current %duA
  ",
  			pdata->max_uA);
  		return -EINVAL;
  	}
  
  	isink = regulator_get(&pdev->dev, "led_isink");
  	if (IS_ERR(isink)) {

  		printk(KERN_ERR "%s: can't get ISINK
  ", __func__);

  		return PTR_ERR(isink);
  	}
  
  	dcdc = regulator_get(&pdev->dev, "led_vcc");
  	if (IS_ERR(dcdc)) {

  		printk(KERN_ERR "%s: can't get DCDC
  ", __func__);

  		ret = PTR_ERR(dcdc);
  		goto err_isink;
  	}

  	led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);

  	if (led == NULL) {
  		ret = -ENOMEM;
  		goto err_dcdc;
  	}
  
  	led->cdev.brightness_set = wm8350_led_set;
  	led->cdev.default_trigger = pdata->default_trigger;
  	led->cdev.name = pdata->name;

  	led->cdev.flags |= LED_CORE_SUSPENDRESUME;

  	led->enabled = regulator_is_enabled(isink);
  	led->isink = isink;
  	led->dcdc = dcdc;
  
  	for (i = 0; i < ARRAY_SIZE(isink_cur) - 1; i++)
  		if (isink_cur[i] >= pdata->max_uA)
  			break;
  	led->max_uA_index = i;
  	if (pdata->max_uA != isink_cur[i])
  		dev_warn(&pdev->dev,
  			 "Maximum current %duA is not directly supported,"
  			 " check platform data
  ",
  			 pdata->max_uA);
  
  	spin_lock_init(&led->value_lock);
  	mutex_init(&led->mutex);
  	INIT_WORK(&led->work, led_work);
  	led->value = LED_OFF;
  	platform_set_drvdata(pdev, led);
  
  	ret = led_classdev_register(&pdev->dev, &led->cdev);
  	if (ret < 0)

  		goto err_dcdc;

  
  	return 0;

   err_dcdc:
  	regulator_put(dcdc);
   err_isink:
  	regulator_put(isink);
  	return ret;
  }
  
  static int wm8350_led_remove(struct platform_device *pdev)
  {
  	struct wm8350_led *led = platform_get_drvdata(pdev);
  
  	led_classdev_unregister(&led->cdev);

  	flush_work_sync(&led->work);

  	wm8350_led_disable(led);
  	regulator_put(led->dcdc);
  	regulator_put(led->isink);

  	return 0;
  }
  
  static struct platform_driver wm8350_led_driver = {
  	.driver = {
  		   .name = "wm8350-led",
  		   .owner = THIS_MODULE,
  		   },
  	.probe = wm8350_led_probe,
  	.remove = wm8350_led_remove,
  	.shutdown = wm8350_led_shutdown,

  };

  module_platform_driver(wm8350_led_driver);

  
  MODULE_AUTHOR("Mark Brown");
  MODULE_DESCRIPTION("WM8350 LED driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:wm8350-led");