xref: /openbmc/linux/drivers/gpu/drm/gma500/backlight.c (revision a2818ee4)
1 /*
2  * GMA500 Backlight Interface
3  *
4  * Copyright (c) 2009-2011, Intel Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License along with
16  * this program; if not, write to the Free Software Foundation, Inc.,
17  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18  *
19  * Authors: Eric Knopp
20  *
21  */
22 
23 #include "psb_drv.h"
24 #include "psb_intel_reg.h"
25 #include "psb_intel_drv.h"
26 #include "intel_bios.h"
27 #include "power.h"
28 
29 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
30 static void do_gma_backlight_set(struct drm_device *dev)
31 {
32 	struct drm_psb_private *dev_priv = dev->dev_private;
33 	backlight_update_status(dev_priv->backlight_device);
34 }
35 #endif
36 
37 void gma_backlight_enable(struct drm_device *dev)
38 {
39 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
40 	struct drm_psb_private *dev_priv = dev->dev_private;
41 	dev_priv->backlight_enabled = true;
42 	if (dev_priv->backlight_device) {
43 		dev_priv->backlight_device->props.brightness = dev_priv->backlight_level;
44 		do_gma_backlight_set(dev);
45 	}
46 #endif
47 }
48 
49 void gma_backlight_disable(struct drm_device *dev)
50 {
51 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
52 	struct drm_psb_private *dev_priv = dev->dev_private;
53 	dev_priv->backlight_enabled = false;
54 	if (dev_priv->backlight_device) {
55 		dev_priv->backlight_device->props.brightness = 0;
56 		do_gma_backlight_set(dev);
57 	}
58 #endif
59 }
60 
61 void gma_backlight_set(struct drm_device *dev, int v)
62 {
63 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
64 	struct drm_psb_private *dev_priv = dev->dev_private;
65 	dev_priv->backlight_level = v;
66 	if (dev_priv->backlight_device && dev_priv->backlight_enabled) {
67 		dev_priv->backlight_device->props.brightness = v;
68 		do_gma_backlight_set(dev);
69 	}
70 #endif
71 }
72 
73 int gma_backlight_init(struct drm_device *dev)
74 {
75 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
76 	struct drm_psb_private *dev_priv = dev->dev_private;
77 	dev_priv->backlight_enabled = true;
78 	return dev_priv->ops->backlight_init(dev);
79 #else
80 	return 0;
81 #endif
82 }
83 
84 void gma_backlight_exit(struct drm_device *dev)
85 {
86 #ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
87 	struct drm_psb_private *dev_priv = dev->dev_private;
88 	if (dev_priv->backlight_device) {
89 		dev_priv->backlight_device->props.brightness = 0;
90 		backlight_update_status(dev_priv->backlight_device);
91 		backlight_device_unregister(dev_priv->backlight_device);
92 	}
93 #endif
94 }
95