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