text: // SPDX-License-Identifier: GPL-2.0-only
  /*
   * GMA500 Backlight Interface
   *
   * Copyright (c) 2009-2011, Intel Corporation.
   *
   * Authors: Eric Knopp
   */
  
  #include "psb_drv.h"
  #include "psb_intel_reg.h"
  #include "psb_intel_drv.h"
  #include "intel_bios.h"
  #include "power.h"
  
  #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
  static void do_gma_backlight_set(struct drm_device *dev)
  {
  	struct drm_psb_private *dev_priv = dev->dev_private;
  	backlight_update_status(dev_priv->backlight_device);
  }
  #endif
  
  void gma_backlight_enable(struct drm_device *dev)
  {
  #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
  	struct drm_psb_private *dev_priv = dev->dev_private;
  	dev_priv->backlight_enabled = true;
  	if (dev_priv->backlight_device) {
  		dev_priv->backlight_device->props.brightness = dev_priv->backlight_level;
  		do_gma_backlight_set(dev);
  	}
  #endif	
  }
  
  void gma_backlight_disable(struct drm_device *dev)
  {
  #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
  	struct drm_psb_private *dev_priv = dev->dev_private;
  	dev_priv->backlight_enabled = false;
  	if (dev_priv->backlight_device) {
  		dev_priv->backlight_device->props.brightness = 0;
  		do_gma_backlight_set(dev);
  	}
  #endif	
  }
  
  void gma_backlight_set(struct drm_device *dev, int v)
  {
  #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
  	struct drm_psb_private *dev_priv = dev->dev_private;
  	dev_priv->backlight_level = v;
  	if (dev_priv->backlight_device && dev_priv->backlight_enabled) {
  		dev_priv->backlight_device->props.brightness = v;
  		do_gma_backlight_set(dev);
  	}
  #endif	
  }
  
  int gma_backlight_init(struct drm_device *dev)
  {
  #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
  	struct drm_psb_private *dev_priv = dev->dev_private;
  	dev_priv->backlight_enabled = true;
  	return dev_priv->ops->backlight_init(dev);
  #else
  	return 0;
  #endif
  }
  
  void gma_backlight_exit(struct drm_device *dev)
  {
  #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
  	struct drm_psb_private *dev_priv = dev->dev_private;
  	if (dev_priv->backlight_device) {
  		dev_priv->backlight_device->props.brightness = 0;
  		backlight_update_status(dev_priv->backlight_device);
  		backlight_device_unregister(dev_priv->backlight_device);
  	}
  #endif
  }
  