1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2020 Emmanuel Vadot <manu@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 */
29
30 #include <sys/types.h>
31 #include <sys/ioctl.h>
32 #include <stdbool.h>
33 #include <sys/backlight.h>
34
35 #include <err.h>
36 #include <errno.h>
37 #include <fcntl.h>
38 #include <limits.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43
44 #define BACKLIGHT_QUERY 0x0001
45 #define BACKLIGHT_SET_BRIGHTNESS 0x0002
46 #define BACKLIGHT_INCR 0x0004
47 #define BACKLIGHT_DECR 0x0008
48 #define BACKLIGHT_INFO 0x0010
49
50 static char device_name[PATH_MAX] = "/dev/backlight/backlight0";
51
52 static void
set_device_name(const char * name)53 set_device_name(const char *name)
54 {
55
56 if (name[0] == '/')
57 strlcpy(device_name, name, sizeof(device_name));
58 else
59 snprintf(device_name, sizeof(device_name), "/dev/backlight/%s", name);
60 }
61
62 static void
usage(void)63 usage(void)
64 {
65 fprintf(stderr, "Usage:\n");
66 fprintf(stderr, "\tbacklight [-q] [-f device]\n");
67 fprintf(stderr, "\tbacklight [-q] [-f device] -i\n");
68 fprintf(stderr, "\tbacklight [-f device] value\n");
69 fprintf(stderr, "\tbacklight [-f device] incr|+ value\n");
70 fprintf(stderr, "\tbacklight [-f device] decr|- value\n");
71 exit(1);
72 }
73
74 static const char *
backlight_type_to_string(enum backlight_info_type type)75 backlight_type_to_string(enum backlight_info_type type)
76 {
77 switch (type) {
78 case BACKLIGHT_TYPE_PANEL:
79 return ("Panel");
80 case BACKLIGHT_TYPE_KEYBOARD:
81 return ("Keyboard");
82 }
83
84 return ("Unknown");
85 }
86
87 int
main(int argc,char * argv[])88 main(int argc, char *argv[])
89 {
90 struct backlight_props props;
91 struct backlight_info info;
92 int fd;
93 int action, ch;
94 long percent = -1;
95 const char *percent_error;
96 uint32_t i;
97 bool quiet = false;
98
99 action = BACKLIGHT_QUERY;
100 fd = -1;
101
102 while ((ch = getopt(argc, argv, "f:qhi")) != -1) {
103 switch (ch) {
104 case 'q':
105 quiet = true;
106 break;
107 case 'f':
108 set_device_name(optarg);
109 break;
110 case 'i':
111 action = BACKLIGHT_INFO;
112 break;
113 case 'h':
114 usage();
115 break;
116 }
117 }
118
119 argc -= optind;
120 argv += optind;
121 if (argc != 0) {
122 if (strcmp("incr", argv[0]) == 0 ||
123 strcmp("+", argv[0]) == 0) {
124 action = BACKLIGHT_INCR;
125 argc -= 1;
126 argv += 1;
127 }
128 else if (strcmp("decr", argv[0]) == 0 ||
129 strcmp("-", argv[0]) == 0) {
130 action = BACKLIGHT_DECR;
131 argc -= 1;
132 argv += 1;
133 } else
134 action = BACKLIGHT_SET_BRIGHTNESS;
135
136 if (argc == 1) {
137 /* ignore a trailing % for user friendlyness */
138 if (strlen(argv[0]) > 0 &&
139 argv[0][strlen(argv[0]) - 1] == '%')
140 argv[0][strlen(argv[0]) - 1] = '\0';
141 percent = strtonum(argv[0], 0, 100, &percent_error);
142 if (percent_error)
143 errx(1, "Cannot parse brightness level %s: %s",
144 argv[0],
145 percent_error);
146 }
147 }
148
149 if ((fd = open(device_name, O_RDWR)) == -1)
150 errx(1, "cannot open %s: %s",
151 device_name, strerror(errno));
152
153 switch (action) {
154 case BACKLIGHT_QUERY:
155 if (ioctl(fd, BACKLIGHTGETSTATUS, &props) == -1)
156 errx(1, "Cannot query the backlight device");
157 if (quiet)
158 printf("%u\n", props.brightness);
159 else {
160 printf("brightness: %d\n", props.brightness);
161 if (props.nlevels != 0) {
162 printf("levels:");
163 for (i = 0; i < props.nlevels; i++)
164 printf(" %d", props.levels[i]);
165 printf("\n");
166 }
167 }
168 break;
169 case BACKLIGHT_SET_BRIGHTNESS:
170 if (percent == -1)
171 usage();
172 props.brightness = percent;
173 if (ioctl(fd, BACKLIGHTUPDATESTATUS, &props) == -1)
174 errx(1, "Cannot update the backlight device");
175 break;
176 case BACKLIGHT_INCR:
177 case BACKLIGHT_DECR:
178 if (percent == 0)
179 /* Avoid any ioctl if we don't have anything to do */
180 break;
181 if (ioctl(fd, BACKLIGHTGETSTATUS, &props) == -1)
182 errx(1, "Cannot query the backlight device");
183 percent = percent == -1 ? 10 : percent;
184 percent = action == BACKLIGHT_INCR ? percent : -percent;
185 props.brightness += percent;
186 if ((int)props.brightness < 0)
187 props.brightness = 0;
188 if (props.brightness > 100)
189 props.brightness = 100;
190 if (ioctl(fd, BACKLIGHTUPDATESTATUS, &props) == -1)
191 errx(1, "Cannot update the backlight device");
192 break;
193 case BACKLIGHT_INFO:
194 if (ioctl(fd, BACKLIGHTGETINFO, &info) == -1)
195 errx(1, "Cannot query the backlight device");
196 if (quiet == false) {
197 printf("Backlight name: %s\n", info.name);
198 printf("Backlight hardware type: %s\n", backlight_type_to_string(info.type));
199 } else {
200 printf("%s\n", info.name);
201 printf("%s\n", backlight_type_to_string(info.type));
202 }
203 break;
204 }
205
206 close(fd);
207 return (0);
208 }
209