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
gma_backlight_enable(struct drm_device * dev)22 void 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
gma_backlight_disable(struct drm_device * dev)30 void 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
gma_backlight_set(struct drm_device * dev,int v)38 void 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
gma_backlight_get_brightness(struct backlight_device * bd)47 static 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
gma_backlight_update_status(struct backlight_device * bd)58 static 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
71 static 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
gma_backlight_init(struct drm_device * dev)76 int 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
gma_backlight_exit(struct drm_device * dev)111 void 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 }
120