Add backlight(8)

This tool is used to configure registered backlights.
It can incr/decr (default to 10%) or accept a percentage value directly.

Reviewed by:	manpages (gbe@)
Relnotes:	yes
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D26251
This commit is contained in:
Emmanuel Vadot 2020-10-02 18:21:30 +00:00
parent 675aae732d
commit 9ddaa99d9d
4 changed files with 322 additions and 0 deletions

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@ -7,6 +7,7 @@ SUBDIR= alias \
apply \ apply \
asa \ asa \
awk \ awk \
backlight \
banner \ banner \
basename \ basename \
brandelf \ brandelf \

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@ -0,0 +1,6 @@
# $FreeBSD$
PROG= backlight
MAN= backlight.8
.include <bsd.prog.mk>

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.\" Copyright (c) 2020 Emmanuel Vadot <manu@freebsd.org>
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd October 02, 2020
.Dt BACKLIGHT 8
.Os
.Sh NAME
.Nm backlight
.Nd configure backlight hardware
.Sh SYNOPSIS
.Nm
.Op Fl f Ar device
.Op Fl q
.Op Fl i
.Op Ar value
.Nm
.Op Fl f Ar device
incr | +
.Op Ar value
.Nm
.Op Fl f Ar device
decr | -
.Op Ar value
.Sh DESCRIPTION
The
.Nm
utility can be used to configure brightness levels for registered backlights
.Pp
The options are as follows:
.Bl -tag -width "-f device"
.It Fl f Ar device
Device to operate on.
If not specified,
.Pa /dev/backlight/backlight0
is used.
If an unqualified name is provided,
.Pa /dev/backlight
is automatically prepended.
.It Fl q
When querying the brightness level only print the value.
.It Fl i
Query information about the backlight (name, type).
.It Ar value
Set the brightness level to this value, must be between 0 and 100.
.It Ar incr | +
.Op Ar value
Decrement the backlight level.
If no value is specified a default of 10 percent is used.
.It Ar decr | -
.Op Ar value
Increment the backlight level.
If no value is specified a default of 10 percent is used.
.El
.Sh EXAMPLES
.Bl -bullet
.It
Show the current brightness level
.Bd -literal
backlight -f /dev/backlight/backlight0
.Ed
.El
.Sh SEE ALSO
.Xr backlight 9
.Sh HISTORY
The
.Nm
utility appeared in
.Fx 13.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
utility and this manual page were written by
.An Emmanuel Vadot Aq Mt manu@FreeBSD.org .

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 Emmanuel Vadot <manu@FreeBSD.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/types.h>
#include <sys/ioctl.h>
#include <stdbool.h>
#include <sys/capsicum.h>
#include <sys/backlight.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <capsicum_helpers.h>
#define BACKLIGHT_QUERY 0x0001
#define BACKLIGHT_SET_BRIGHTNESS 0x0002
#define BACKLIGHT_INCR 0x0004
#define BACKLIGHT_DECR 0x0008
#define BACKLIGHT_INFO 0x0010
static char device_name[PATH_MAX] = "/dev/backlight/backlight0";
static void
set_device_name(const char *name)
{
if (name[0] == '/')
strlcpy(device_name, name, sizeof(device_name));
else
snprintf(device_name, sizeof(device_name), "/dev/backlight/%s", name);
}
static void
usage(void)
{
fprintf(stderr, "Usage:\n");
fprintf(stderr, "\tbacklight [-f dev]\n");
fprintf(stderr, "\tbacklight [-f dev] -i\n");
fprintf(stderr, "\tbacklight [-f dev] <percent>\n");
fprintf(stderr, "\tbacklight [-f dev] incr|+ <percent>\n");
fprintf(stderr, "\tbacklight [-f dev] decr|- <percent>\n");
exit(1);
}
static const char *
backlight_type_to_string(enum backlight_info_type type)
{
switch (type) {
case BACKLIGHT_TYPE_PANEL:
return ("Panel");
case BACKLIGHT_TYPE_KEYBOARD:
return ("Keyboard");
}
return ("Unknown");
}
int
main(int argc, char *argv[])
{
struct backlight_props props;
struct backlight_info info;
int fd;
int action, ch;
cap_rights_t right_ioctl;
const unsigned long backlight_ioctls[] = {
BACKLIGHTGETSTATUS,
BACKLIGHTUPDATESTATUS,
BACKLIGHTGETINFO};
long percent = 0;
const char *percent_error;
uint32_t i;
bool setname;
bool quiet = false;
action = BACKLIGHT_QUERY;
setname = false;
fd = -1;
while ((ch = getopt(argc, argv, "f:qhi")) != -1) {
switch (ch) {
case 'q':
quiet = true;
break;
case 'f':
setname = true;
set_device_name(optarg);
break;
case 'i':
action = BACKLIGHT_INFO;
break;
case 'h':
usage();
break;
}
}
argc -= optind;
argv += optind;
if (argc != 0) {
if (strcmp("incr", argv[0]) == 0 ||
strcmp("+", argv[0]) == 0) {
action = BACKLIGHT_INCR;
argc -= 1;
argv += 1;
}
else if (strcmp("decr", argv[0]) == 0 ||
strcmp("-", argv[0]) == 0) {
action = BACKLIGHT_DECR;
argc -= 1;
argv += 1;
} else
action = BACKLIGHT_SET_BRIGHTNESS;
if (argc == 1) {
percent = strtonum(argv[0], 0, 100, &percent_error);
if (percent_error)
errx(1, "Cannot parse brightness level %s: %s",
argv[0],
percent_error);
}
}
if ((fd = open(device_name, O_RDWR)) == -1)
errx(1, "cannot open %s: %s",
device_name, strerror(errno));
if (caph_limit_stdio() < 0)
errx(1, "can't limit stdio rights");
caph_cache_catpages();
cap_rights_init(&right_ioctl, CAP_IOCTL);
if (caph_rights_limit(fd, &right_ioctl) < 0)
errx(1, "cap_right_limit() failed");
if (caph_ioctls_limit(fd, backlight_ioctls, nitems(backlight_ioctls)) < 0)
errx(1, "caph_ioctls_limit() failed");
if (caph_enter() < 0)
errx(1, "failed to enter capability mode");
switch (action) {
case BACKLIGHT_QUERY:
if (ioctl(fd, BACKLIGHTGETSTATUS, &props) == -1)
errx(1, "Cannot query the backlight device");
if (quiet)
printf("%u\n", props.brightness);
else {
printf("brightness: %d\n", props.brightness);
if (props.nlevels != 0) {
printf("levels:");
for (i = 0; i < props.nlevels; i++)
printf(" %d", props.levels[i]);
printf("\n");
}
}
break;
case BACKLIGHT_SET_BRIGHTNESS:
props.brightness = percent;
if (ioctl(fd, BACKLIGHTUPDATESTATUS, &props) == -1)
errx(1, "Cannot update the backlight device");
break;
case BACKLIGHT_INCR:
case BACKLIGHT_DECR:
if (ioctl(fd, BACKLIGHTGETSTATUS, &props) == -1)
errx(1, "Cannot query the backlight device");
percent = percent == 0 ? 10 : percent;
percent = action == BACKLIGHT_INCR ? percent : -percent;
props.brightness += percent;
if ((int)props.brightness < 0)
props.brightness = 0;
if (props.brightness > 100)
props.brightness = 100;
if (ioctl(fd, BACKLIGHTUPDATESTATUS, &props) == -1)
errx(1, "Cannot update the backlight device");
break;
case BACKLIGHT_INFO:
if (ioctl(fd, BACKLIGHTGETINFO, &info) == -1)
errx(1, "Cannot query the backlight device");
if (quiet == false) {
printf("Backlight name: %s\n", info.name);
printf("Backlight hardware type: %s\n", backlight_type_to_string(info.type));
} else {
printf("%s\n", info.name);
printf("%s\n", backlight_type_to_string(info.type));
}
break;
}
close(fd);
return (0);
}