backlight.c

  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 <drm/drm_print.h>
 15
 16#include "psb_drv.h"
 17#include "psb_intel_reg.h"
 18#include "psb_intel_drv.h"
 19#include "intel_bios.h"
 20#include "power.h"
 21
 22void gma_backlight_enable(struct drm_device *dev)
 23{
 24	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 25
 26	dev_priv->backlight_enabled = true;
 27	dev_priv->ops->backlight_set(dev, dev_priv->backlight_level);
 28}
 29
 30void gma_backlight_disable(struct drm_device *dev)
 31{
 32	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 33
 34	dev_priv->backlight_enabled = false;
 35	dev_priv->ops->backlight_set(dev, 0);
 36}
 37
 38void gma_backlight_set(struct drm_device *dev, int v)
 39{
 40	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 41
 42	dev_priv->backlight_level = v;
 43	if (dev_priv->backlight_enabled)
 44		dev_priv->ops->backlight_set(dev, v);
 45}
 46
 47static int gma_backlight_get_brightness(struct backlight_device *bd)
 48{
 49	struct drm_device *dev = bl_get_data(bd);
 50	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 51
 52	if (dev_priv->ops->backlight_get)
 53		return dev_priv->ops->backlight_get(dev);
 54
 55	return dev_priv->backlight_level;
 56}
 57
 58static int gma_backlight_update_status(struct backlight_device *bd)
 59{
 60	struct drm_device *dev = bl_get_data(bd);
 61	int level = backlight_get_brightness(bd);
 62
 63	/* Percentage 1-100% being valid */
 64	if (level < 1)
 65		level = 1;
 66
 67	gma_backlight_set(dev, level);
 68	return 0;
 69}
 70
 71static const struct backlight_ops gma_backlight_ops __maybe_unused = {
 72	.get_brightness = gma_backlight_get_brightness,
 73	.update_status  = gma_backlight_update_status,
 74};
 75
 76int gma_backlight_init(struct drm_device *dev)
 77{
 78	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 79	struct backlight_properties props __maybe_unused = {};
 80	int ret;
 81
 82	dev_priv->backlight_enabled = true;
 83	dev_priv->backlight_level = 100;
 84
 85	ret = dev_priv->ops->backlight_init(dev);
 86	if (ret)
 87		return ret;
 88
 89	if (!acpi_video_backlight_use_native()) {
 90		drm_info(dev, "Skipping %s backlight registration\n",
 91			 dev_priv->ops->backlight_name);
 92		return 0;
 93	}
 94
 95#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
 96	props.brightness = dev_priv->backlight_level;
 97	props.max_brightness = PSB_MAX_BRIGHTNESS;
 98	props.type = BACKLIGHT_RAW;
 99
100	dev_priv->backlight_device =
101		backlight_device_register(dev_priv->ops->backlight_name,
102					  dev->dev, dev,
103					  &gma_backlight_ops, &props);
104	if (IS_ERR(dev_priv->backlight_device))
105		return PTR_ERR(dev_priv->backlight_device);
106#endif
107
108	return 0;
109}
110
111void gma_backlight_exit(struct drm_device *dev)
112{
113#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
114	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
115
116	if (dev_priv->backlight_device)
117		backlight_device_unregister(dev_priv->backlight_device);
118#endif
119}