1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
/*
* Copyright © 2012 Intel Corporation
*
* Permission to use, copy, modify, distribute, and sell this software and
* its documentation for any purpose is hereby granted without fee, provided
* that the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of the copyright holders not be used in
* advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. The copyright holders make
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
* RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
* CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Author: Tiago Vignatti
*/
/*
* \file setbacklight.c
* Test program to get a backlight connector and set its brightness value.
* Queries for the connectors id can be performed using drm/tests/modeprint
* program.
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <xf86drm.h>
#include <xf86drmMode.h>
#include "libbacklight.h"
static uint32_t
get_drm_connector_type(struct udev_device *drm_device, uint32_t connector_id)
{
const char *filename;
int fd, i, connector_type;
drmModeResPtr res;
drmModeConnectorPtr connector;
filename = udev_device_get_devnode(drm_device);
fd = open(filename, O_RDWR | O_CLOEXEC);
if (fd < 0) {
printf("couldn't open drm_device\n");
return -1;
}
res = drmModeGetResources(fd);
if (res == 0) {
printf("Failed to get resources from card\n");
close(fd);
return -1;
}
for (i = 0; i < res->count_connectors; i++) {
connector = drmModeGetConnector(fd, res->connectors[i]);
if (!connector)
continue;
if ((connector->connection == DRM_MODE_DISCONNECTED) ||
(connector->connector_id != connector_id)) {
drmModeFreeConnector(connector);
continue;
}
connector_type = connector->connector_type;
drmModeFreeConnector(connector);
drmModeFreeResources(res);
close(fd);
return connector_type;
}
close(fd);
drmModeFreeResources(res);
return -1;
}
/* returns a value between 0-255 range, where higher is brighter */
static uint32_t
get_normalized_backlight(struct backlight *backlight)
{
long brightness, max_brightness;
long norm;
brightness = backlight_get_brightness(backlight);
max_brightness = backlight_get_max_brightness(backlight);
/* convert it to a scale of 0 to 255 */
norm = (brightness * 255)/(max_brightness);
return (int) norm;
}
static void
set_backlight(struct udev_device *drm_device, int connector_id, int blight)
{
int connector_type;
long max_brightness, brightness, actual_brightness;
struct backlight *backlight;
long new_blight;
connector_type = get_drm_connector_type(drm_device, connector_id);
if (connector_type < 0)
return;
backlight = backlight_init(drm_device, connector_type);
if (!backlight) {
printf("backlight adjust failed\n");
return;
}
max_brightness = backlight_get_max_brightness(backlight);
printf("Max backlight: %ld\n", max_brightness);
brightness = backlight_get_brightness(backlight);
printf("Cached backlight: %ld\n", brightness);
actual_brightness = backlight_get_actual_brightness(backlight);
printf("Hardware backlight: %ld\n", actual_brightness);
printf("normalized current brightness: %d\n",
get_normalized_backlight(backlight));
/* denormalized value */
new_blight = (blight * max_brightness) / 255;
backlight_set_brightness(backlight, new_blight);
printf("Setting brightness to: %ld (norm: %d)\n", new_blight, blight);
backlight_destroy(backlight);
}
int
main(int argc, char **argv)
{
int blight, connector_id;
const char *path;
struct udev *udev;
struct udev_enumerate *e;
struct udev_list_entry *entry;
struct udev_device *drm_device;
if (argc < 3) {
printf("Please add connector_id and brightness values from 0-255\n");
return 1;
}
connector_id = atoi(argv[1]);
blight = atoi(argv[2]);
udev = udev_new();
if (udev == NULL) {
printf("failed to initialize udev context\n");
return 1;
}
e = udev_enumerate_new(udev);
udev_enumerate_add_match_subsystem(e, "drm");
udev_enumerate_add_match_sysname(e, "card[0-9]*");
udev_enumerate_scan_devices(e);
drm_device = NULL;
udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(e)) {
path = udev_list_entry_get_name(entry);
drm_device = udev_device_new_from_syspath(udev, path);
break;
}
if (drm_device == NULL) {
printf("no drm device found\n");
return 1;
}
set_backlight(drm_device, connector_id, blight);
udev_device_unref(drm_device);
return 0;
}
|
