342 lines
12 KiB
C
342 lines
12 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
|
|
|
|
/***
|
|
This file is part of systemd.
|
|
|
|
Copyright 2013 Lennart Poettering
|
|
|
|
systemd is free software; you can redistribute it and/or modify it
|
|
under the terms of the GNU Lesser General Public License as published by
|
|
the Free Software Foundation; either version 2.1 of the License, or
|
|
(at your option) any later version.
|
|
|
|
systemd is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with systemd; If not, see <http://www.gnu.org/licenses/>.
|
|
***/
|
|
|
|
#include "util.h"
|
|
#include "mkdir.h"
|
|
#include "fileio.h"
|
|
#include "libudev.h"
|
|
#include "udev-util.h"
|
|
|
|
static struct udev_device *find_pci_or_platform_parent(struct udev_device *device) {
|
|
struct udev_device *parent;
|
|
const char *subsystem, *sysname;
|
|
|
|
assert(device);
|
|
|
|
parent = udev_device_get_parent(device);
|
|
if (!parent)
|
|
return NULL;
|
|
|
|
subsystem = udev_device_get_subsystem(parent);
|
|
if (!subsystem)
|
|
return NULL;
|
|
|
|
sysname = udev_device_get_sysname(parent);
|
|
if (!sysname)
|
|
return NULL;
|
|
|
|
if (streq(subsystem, "drm")) {
|
|
const char *c;
|
|
|
|
c = startswith(sysname, "card");
|
|
if (!c)
|
|
return NULL;
|
|
|
|
c += strspn(c, "0123456789");
|
|
if (*c == '-') {
|
|
/* A connector DRM device, let's ignore all but LVDS and eDP! */
|
|
|
|
if (!startswith(c, "-LVDS-") &&
|
|
!startswith(c, "-Embedded DisplayPort-"))
|
|
return NULL;
|
|
}
|
|
|
|
} else if (streq(subsystem, "pci")) {
|
|
const char *value;
|
|
|
|
value = udev_device_get_sysattr_value(parent, "class");
|
|
if (value) {
|
|
unsigned long class;
|
|
|
|
if (safe_atolu(value, &class) < 0) {
|
|
log_warning("Cannot parse PCI class %s of device %s:%s.", value, subsystem, sysname);
|
|
return NULL;
|
|
}
|
|
|
|
/* Graphics card */
|
|
if (class == 0x30000)
|
|
return parent;
|
|
}
|
|
|
|
} else if (streq(subsystem, "platform"))
|
|
return parent;
|
|
|
|
return find_pci_or_platform_parent(parent);
|
|
}
|
|
|
|
static bool same_device(struct udev_device *a, struct udev_device *b) {
|
|
assert(a);
|
|
assert(b);
|
|
|
|
if (!streq_ptr(udev_device_get_subsystem(a), udev_device_get_subsystem(b)))
|
|
return false;
|
|
|
|
if (!streq_ptr(udev_device_get_sysname(a), udev_device_get_sysname(b)))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool validate_device(struct udev *udev, struct udev_device *device) {
|
|
_cleanup_udev_enumerate_unref_ struct udev_enumerate *enumerate = NULL;
|
|
struct udev_list_entry *item = NULL, *first = NULL;
|
|
struct udev_device *parent;
|
|
const char *v, *subsystem;
|
|
int r;
|
|
|
|
assert(udev);
|
|
assert(device);
|
|
|
|
/* Verify whether we should actually care for a specific
|
|
* backlight device. For backlight devices there might be
|
|
* multiple ways to access the same control: "firmware"
|
|
* (i.e. ACPI), "platform" (i.e. via the machine's EC) and
|
|
* "raw" (via the graphics card). In general we should prefer
|
|
* "firmware" (i.e. ACPI) or "platform" access over "raw"
|
|
* access, in order not to confuse the BIOS/EC, and
|
|
* compatibility with possible low-level hotkey handling of
|
|
* screen brightness. The kernel will already make sure to
|
|
* expose only one of "firmware" and "platform" for the same
|
|
* device to userspace. However, we still need to make sure
|
|
* that we use "raw" only if no "firmware" or "platform"
|
|
* device for the same device exists. */
|
|
|
|
subsystem = udev_device_get_subsystem(device);
|
|
if (!streq_ptr(subsystem, "backlight"))
|
|
return true;
|
|
|
|
v = udev_device_get_sysattr_value(device, "type");
|
|
if (!streq_ptr(v, "raw"))
|
|
return true;
|
|
|
|
parent = find_pci_or_platform_parent(device);
|
|
if (!parent)
|
|
return true;
|
|
|
|
subsystem = udev_device_get_subsystem(parent);
|
|
if (!subsystem)
|
|
return true;
|
|
|
|
enumerate = udev_enumerate_new(udev);
|
|
if (!enumerate)
|
|
return true;
|
|
|
|
r = udev_enumerate_add_match_subsystem(enumerate, "backlight");
|
|
if (r < 0)
|
|
return true;
|
|
|
|
r = udev_enumerate_scan_devices(enumerate);
|
|
if (r < 0)
|
|
return true;
|
|
|
|
first = udev_enumerate_get_list_entry(enumerate);
|
|
udev_list_entry_foreach(item, first) {
|
|
_cleanup_udev_device_unref_ struct udev_device *other;
|
|
struct udev_device *other_parent;
|
|
const char *other_subsystem;
|
|
|
|
other = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
|
|
if (!other)
|
|
return true;
|
|
|
|
if (same_device(device, other))
|
|
continue;
|
|
|
|
v = udev_device_get_sysattr_value(other, "type");
|
|
if (!streq_ptr(v, "platform") && !streq_ptr(v, "firmware"))
|
|
continue;
|
|
|
|
/* OK, so there's another backlight device, and it's a
|
|
* platform or firmware device, so, let's see if we
|
|
* can verify it belongs to the same device as
|
|
* ours. */
|
|
other_parent = find_pci_or_platform_parent(other);
|
|
if (!other_parent)
|
|
continue;
|
|
|
|
if (same_device(parent, other_parent)) {
|
|
/* Both have the same PCI parent, that means
|
|
* we are out. */
|
|
log_debug("Skipping backlight device %s, since backlight device %s is on same PCI device and, takes precedence.", udev_device_get_sysname(device), udev_device_get_sysname(other));
|
|
return false;
|
|
}
|
|
|
|
other_subsystem = udev_device_get_subsystem(other_parent);
|
|
if (streq_ptr(other_subsystem, "platform") && streq_ptr(subsystem, "pci")) {
|
|
/* The other is connected to the platform bus
|
|
* and we are a PCI device, that also means we
|
|
* are out. */
|
|
log_debug("Skipping backlight device %s, since backlight device %s is a platform device and takes precedence.", udev_device_get_sysname(device), udev_device_get_sysname(other));
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
int main(int argc, char *argv[]) {
|
|
_cleanup_udev_unref_ struct udev *udev = NULL;
|
|
_cleanup_udev_device_unref_ struct udev_device *device = NULL;
|
|
_cleanup_free_ char *saved = NULL, *ss = NULL, *escaped_ss = NULL, *escaped_sysname = NULL, *escaped_path_id = NULL;
|
|
const char *sysname, *path_id;
|
|
int r;
|
|
|
|
if (argc != 3) {
|
|
log_error("This program requires two arguments.");
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
log_set_target(LOG_TARGET_AUTO);
|
|
log_parse_environment();
|
|
log_open();
|
|
|
|
umask(0022);
|
|
|
|
r = mkdir_p("/var/lib/systemd/backlight", 0755);
|
|
if (r < 0) {
|
|
log_error("Failed to create backlight directory: %s", strerror(-r));
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
udev = udev_new();
|
|
if (!udev) {
|
|
log_oom();
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
sysname = strchr(argv[2], ':');
|
|
if (!sysname) {
|
|
log_error("Requires pair of subsystem and sysname for specifying backlight device.");
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
ss = strndup(argv[2], sysname - argv[2]);
|
|
if (!ss) {
|
|
log_oom();
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
sysname++;
|
|
|
|
if (!streq(ss, "backlight") && !streq(ss, "leds")) {
|
|
log_error("Not a backlight or LED device: '%s:%s'", ss, sysname);
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
errno = 0;
|
|
device = udev_device_new_from_subsystem_sysname(udev, ss, sysname);
|
|
if (!device) {
|
|
if (errno != 0)
|
|
log_error("Failed to get backlight or LED device '%s:%s': %m", ss, sysname);
|
|
else
|
|
log_oom();
|
|
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
escaped_ss = cescape(ss);
|
|
if (!escaped_ss) {
|
|
log_oom();
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
escaped_sysname = cescape(sysname);
|
|
if (!escaped_sysname) {
|
|
log_oom();
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
path_id = udev_device_get_property_value(device, "ID_PATH");
|
|
if (path_id) {
|
|
escaped_path_id = cescape(path_id);
|
|
if (!escaped_path_id) {
|
|
log_oom();
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
saved = strjoin("/var/lib/systemd/backlight/", escaped_path_id, ":", escaped_ss, ":", escaped_sysname, NULL);
|
|
} else
|
|
saved = strjoin("/var/lib/systemd/backlight/", escaped_ss, ":", escaped_sysname, NULL);
|
|
|
|
if (!saved) {
|
|
log_oom();
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
/* If there are multiple conflicting backlight devices, then
|
|
* their probing at boot-time might happen in any order. This
|
|
* means the validity checking of the device then is not
|
|
* reliable, since it might not see other devices conflicting
|
|
* with a specific backlight. To deal with this, we will
|
|
* actively delete backlight state files at shutdown (where
|
|
* device probing should be complete), so that the validity
|
|
* check at boot time doesn't have to be reliable. */
|
|
|
|
if (streq(argv[1], "load") && shall_restore_state()) {
|
|
_cleanup_free_ char *value = NULL;
|
|
|
|
if (!validate_device(udev, device))
|
|
return EXIT_SUCCESS;
|
|
|
|
r = read_one_line_file(saved, &value);
|
|
if (r < 0) {
|
|
|
|
if (r == -ENOENT)
|
|
return EXIT_SUCCESS;
|
|
|
|
log_error("Failed to read %s: %s", saved, strerror(-r));
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
r = udev_device_set_sysattr_value(device, "brightness", value);
|
|
if (r < 0) {
|
|
log_error("Failed to write system attribute: %s", strerror(-r));
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
} else if (streq(argv[1], "save")) {
|
|
const char *value;
|
|
|
|
if (!validate_device(udev, device)) {
|
|
unlink(saved);
|
|
return EXIT_SUCCESS;
|
|
}
|
|
|
|
value = udev_device_get_sysattr_value(device, "brightness");
|
|
if (!value) {
|
|
log_error("Failed to read system attribute: %s", strerror(-r));
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
r = write_string_file(saved, value);
|
|
if (r < 0) {
|
|
log_error("Failed to write %s: %s", saved, strerror(-r));
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
} else {
|
|
log_error("Unknown verb %s.", argv[1]);
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
return EXIT_SUCCESS;
|
|
}
|