xref: /openbmc/linux/drivers/gpu/drm/gma500/backlight.c (revision a6276e92)
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 
gma_backlight_enable(struct drm_device * dev)20 void 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 
gma_backlight_disable(struct drm_device * dev)28 void 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 
gma_backlight_set(struct drm_device * dev,int v)36 void 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 
gma_backlight_get_brightness(struct backlight_device * bd)45 static 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 
gma_backlight_update_status(struct backlight_device * bd)56 static 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 
69 static 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 
gma_backlight_init(struct drm_device * dev)74 int 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 
gma_backlight_exit(struct drm_device * dev)109 void 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