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(bl_dev: 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(bl_dev: 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, v: 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(name: dev_priv->ops->backlight_name,
100 dev: dev->dev, devdata: dev,
101 ops: &gma_backlight_ops, props: &props);
102 if (IS_ERR(ptr: dev_priv->backlight_device))
103 return PTR_ERR(ptr: 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(bd: dev_priv->backlight_device);
116#endif
117}
118

source code of linux/drivers/gpu/drm/gma500/backlight.c