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}
118