drivers/gpu/drm/gma500/backlight.c

// 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
}