1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * GMA500 Backlight Interface
  4 *
  5 * Copyright (c) 2009-2011, Intel Corporation.
  6 *
  7 * Authors: Eric Knopp
  8 */
  9
 10#include <linux/backlight.h>
 11
 12#include <acpi/video.h>
 13
 14#include "psb_drv.h"
 15#include "psb_intel_reg.h"
 16#include "psb_intel_drv.h"
 17#include "intel_bios.h"
 18#include "power.h"
 19
 20void gma_backlight_enable(struct drm_device *dev)
 21{
 22	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 23
 24	dev_priv->backlight_enabled = true;
 25	dev_priv->ops->backlight_set(dev, dev_priv->backlight_level);
 26}
 27
 28void gma_backlight_disable(struct drm_device *dev)
 29{
 30	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 31
 32	dev_priv->backlight_enabled = false;
 33	dev_priv->ops->backlight_set(dev, 0);
 34}
 35
 36void gma_backlight_set(struct drm_device *dev, int v)
 37{
 38	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 39
 40	dev_priv->backlight_level = v;
 41	if (dev_priv->backlight_enabled)
 42		dev_priv->ops->backlight_set(dev, v);
 43}
 44
 45static int gma_backlight_get_brightness(struct backlight_device *bd)
 46{
 47	struct drm_device *dev = bl_get_data(bd);
 48	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 49
 50	if (dev_priv->ops->backlight_get)
 51		return dev_priv->ops->backlight_get(dev);
 52
 53	return dev_priv->backlight_level;
 54}
 55
 56static int gma_backlight_update_status(struct backlight_device *bd)
 57{
 58	struct drm_device *dev = bl_get_data(bd);
 59	int level = backlight_get_brightness(bd);
 60
 61	/* Percentage 1-100% being valid */
 62	if (level < 1)
 63		level = 1;
 64
 65	gma_backlight_set(dev, level);
 66	return 0;
 67}
 68
 69static const struct backlight_ops gma_backlight_ops __maybe_unused = {
 70	.get_brightness = gma_backlight_get_brightness,
 71	.update_status  = gma_backlight_update_status,
 72};
 73
 74int gma_backlight_init(struct drm_device *dev)
 75{
 76	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 77	struct backlight_properties props __maybe_unused = {};
 78	int ret;
 79
 80	dev_priv->backlight_enabled = true;
 81	dev_priv->backlight_level = 100;
 82
 83	ret = dev_priv->ops->backlight_init(dev);
 84	if (ret)
 85		return ret;
 86
 87	if (!acpi_video_backlight_use_native()) {
 88		drm_info(dev, "Skipping %s backlight registration\n",
 89			 dev_priv->ops->backlight_name);
 90		return 0;
 91	}
 92
 93#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
 94	props.brightness = dev_priv->backlight_level;
 95	props.max_brightness = PSB_MAX_BRIGHTNESS;
 96	props.type = BACKLIGHT_RAW;
 97
 98	dev_priv->backlight_device =
 99		backlight_device_register(dev_priv->ops->backlight_name,
100					  dev->dev, dev,
101					  &gma_backlight_ops, &props);
102	if (IS_ERR(dev_priv->backlight_device))
103		return PTR_ERR(dev_priv->backlight_device);
104#endif
105
106	return 0;
107}
108
109void gma_backlight_exit(struct drm_device *dev)
110{
111#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
112	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
113
114	if (dev_priv->backlight_device)
115		backlight_device_unregister(dev_priv->backlight_device);
116#endif
117}