-/* SPDX-License-Identifier: LGPL-2.1+ */
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
#include "sd-device.h"
#include "main-func.h"
#include "mkdir.h"
#include "parse-util.h"
-#include "proc-cmdline.h"
+#include "pretty-print.h"
+#include "terminal-util.h"
+#include "reboot-util.h"
#include "string-util.h"
#include "strv.h"
#include "util.h"
+static int help(void) {
+ _cleanup_free_ char *link = NULL;
+ int r;
+
+ r = terminal_urlify_man("systemd-backlight", "8", &link);
+ if (r < 0)
+ return log_oom();
+
+ printf("%s save [backlight|leds]:DEVICE\n"
+ "%s load [backlight|leds]:DEVICE\n"
+ "\n%sSave and restore backlight brightness at shutdown and boot.%s\n\n"
+ " save Save current brightness\n"
+ " load Set brightness to be the previously saved value\n"
+ "\nSee the %s for details.\n"
+ , program_invocation_short_name
+ , program_invocation_short_name
+ , ansi_highlight(), ansi_normal()
+ , link
+ );
+
+ return 0;
+}
+
static int find_pci_or_platform_parent(sd_device *device, sd_device **ret) {
const char *subsystem, *sysname, *value;
sd_device *parent;
} else if (streq(subsystem, "pci") &&
sd_device_get_sysattr_value(parent, "class", &value) >= 0) {
- unsigned long class = 0;
+ unsigned long class;
r = safe_atolu(value, &class);
if (r < 0)
if (r < 0)
return log_device_warning_errno(device, r, "Failed to parse 'max_brightness' \"%s\": %m", max_brightness_str);
- if (max_brightness <= 0) {
- log_device_warning(device, "Maximum brightness is 0, ignoring device.");
- return -EINVAL;
- }
+ if (max_brightness <= 0)
+ return log_device_warning_errno(device, SYNTHETIC_ERRNO(EINVAL), "Maximum brightness is 0, ignoring device.");
*ret = max_brightness;
return 0;
* max_brightness in case of 'backlight' subsystem. This avoids preserving
* an unreadably dim screen, which would otherwise force the user to
* disable state restoration. */
-static int clamp_brightness(sd_device *device, char **value, unsigned max_brightness) {
- unsigned brightness, new_brightness, min_brightness;
+static int clamp_brightness(sd_device *device, bool saved, unsigned max_brightness, unsigned *brightness) {
+ unsigned new_brightness, min_brightness;
const char *subsystem;
int r;
- assert(value);
- assert(*value);
-
- r = safe_atou(*value, &brightness);
- if (r < 0)
- return log_device_warning_errno(device, r, "Failed to parse brightness \"%s\": %m", *value);
+ assert(device);
+ assert(brightness);
r = sd_device_get_subsystem(device, &subsystem);
if (r < 0)
else
min_brightness = 0;
- new_brightness = CLAMP(brightness, min_brightness, max_brightness);
- if (new_brightness != brightness) {
- char *new_value;
-
- r = asprintf(&new_value, "%u", new_brightness);
- if (r < 0)
- return log_oom();
-
- log_device_info(device, "Saved brightness %s %s to %s.", *value,
- new_brightness > brightness ?
+ new_brightness = CLAMP(*brightness, min_brightness, max_brightness);
+ if (new_brightness != *brightness)
+ log_device_info(device, "%s brightness %u is %s to %u.",
+ saved ? "Saved" : "Current",
+ *brightness,
+ new_brightness > *brightness ?
"too low; increasing" : "too high; decreasing",
- new_value);
-
- free_and_replace(*value, new_value);
- }
+ new_brightness);
+ *brightness = new_brightness;
return 0;
}
r = sd_device_get_property_value(d, "ID_BACKLIGHT_CLAMP", &s);
if (r < 0) {
- log_device_debug_errno(d, r, "Failed to get ID_BACKLIGHT_CLAMP property, ignoring: %m");
+ if (r != -ENOENT)
+ log_device_debug_errno(d, r, "Failed to get ID_BACKLIGHT_CLAMP property, ignoring: %m");
return true;
}
return r;
}
+static int read_brightness(sd_device *device, unsigned max_brightness, unsigned *ret_brightness) {
+ const char *subsystem, *value;
+ unsigned brightness;
+ int r;
+
+ assert(device);
+ assert(ret_brightness);
+
+ r = sd_device_get_subsystem(device, &subsystem);
+ if (r < 0)
+ return log_device_debug_errno(device, r, "Failed to get subsystem: %m");
+
+ if (streq(subsystem, "backlight")) {
+ r = sd_device_get_sysattr_value(device, "actual_brightness", &value);
+ if (r == -ENOENT) {
+ log_device_debug_errno(device, r, "Failed to read 'actual_brightness' attribute, "
+ "fall back to use 'brightness' attribute: %m");
+ goto use_brightness;
+ }
+ if (r < 0)
+ return log_device_debug_errno(device, r, "Failed to read 'actual_brightness' attribute: %m");
+
+ r = safe_atou(value, &brightness);
+ if (r < 0) {
+ log_device_debug_errno(device, r, "Failed to parse 'actual_brightness' attribute, "
+ "fall back to use 'brightness' attribute: %s", value);
+ goto use_brightness;
+ }
+
+ if (brightness > max_brightness) {
+ log_device_debug(device, "actual_brightness=%u is larger than max_brightness=%u, "
+ "fall back to use 'brightness' attribute", brightness, max_brightness);
+ goto use_brightness;
+ }
+
+ *ret_brightness = brightness;
+ return 0;
+ }
+
+use_brightness:
+ r = sd_device_get_sysattr_value(device, "brightness", &value);
+ if (r < 0)
+ return log_device_debug_errno(device, r, "Failed to read 'brightness' attribute: %m");
+
+ r = safe_atou(value, &brightness);
+ if (r < 0)
+ return log_device_debug_errno(device, r, "Failed to parse 'brightness' attribute: %s", value);
+
+ if (brightness > max_brightness)
+ return log_device_debug_errno(device, SYNTHETIC_ERRNO(EINVAL),
+ "brightness=%u is larger than max_brightness=%u",
+ brightness, max_brightness);
+
+ *ret_brightness = brightness;
+ return 0;
+}
+
static int run(int argc, char *argv[]) {
_cleanup_(sd_device_unrefp) sd_device *device = NULL;
_cleanup_free_ char *escaped_ss = NULL, *escaped_sysname = NULL, *escaped_path_id = NULL;
const char *sysname, *path_id, *ss, *saved;
- unsigned max_brightness;
+ unsigned max_brightness, brightness;
int r;
- if (argc != 3) {
- log_error("This program requires two arguments.");
- return -EINVAL;
- }
-
log_setup_service();
+ if (strv_contains(strv_skip(argv, 1), "--help"))
+ return help();
+
+ if (argc != 3)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program requires two arguments.");
+
umask(0022);
r = mkdir_p("/var/lib/systemd/backlight", 0755);
return log_error_errno(r, "Failed to create backlight directory /var/lib/systemd/backlight: %m");
sysname = strchr(argv[2], ':');
- if (!sysname) {
- log_error("Requires a subsystem and sysname pair specifying a backlight device.");
- return -EINVAL;
- }
+ if (!sysname)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Requires a subsystem and sysname pair specifying a backlight device.");
ss = strndupa(argv[2], sysname - argv[2]);
sysname++;
- if (!STR_IN_SET(ss, "backlight", "leds")) {
- log_error("Not a backlight or LED device: '%s:%s'", ss, sysname);
- return -EINVAL;
- }
+ if (!STR_IN_SET(ss, "backlight", "leds"))
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Not a backlight or LED device: '%s:%s'", ss, sysname);
r = sd_device_new_from_subsystem_sysname(&device, ss, sysname);
if (r < 0)
clamp = shall_clamp(device);
r = read_one_line_file(saved, &value);
- if (r == -ENOENT) {
- const char *curval;
-
- /* Fallback to clamping current brightness or exit early if
- * clamping is not supported/enabled. */
+ if (r < 0 && r != -ENOENT)
+ return log_error_errno(r, "Failed to read %s: %m", saved);
+ if (r > 0) {
+ r = safe_atou(value, &brightness);
+ if (r < 0) {
+ log_error_errno(r, "Failed to parse saved brightness '%s', removing %s.",
+ value, saved);
+ (void) unlink(saved);
+ } else {
+ if (clamp)
+ (void) clamp_brightness(device, true, max_brightness, &brightness);
+
+ /* Do not fall back to read current brightness below. */
+ r = 1;
+ }
+ }
+ if (r <= 0) {
+ /* Fallback to clamping current brightness or exit early if clamping is not
+ * supported/enabled. */
if (!clamp)
return 0;
- r = sd_device_get_sysattr_value(device, "brightness", &curval);
+ r = read_brightness(device, max_brightness, &brightness);
if (r < 0)
- return log_device_warning_errno(device, r, "Failed to read 'brightness' attribute: %m");
-
- value = strdup(curval);
- if (!value)
- return log_oom();
- } else if (r < 0)
- return log_error_errno(r, "Failed to read %s: %m", saved);
+ return log_device_error_errno(device, r, "Failed to read current brightness: %m");
- if (clamp)
- (void) clamp_brightness(device, &value, max_brightness);
+ (void) clamp_brightness(device, false, max_brightness, &brightness);
+ }
- r = sd_device_set_sysattr_value(device, "brightness", value);
+ r = sd_device_set_sysattr_valuef(device, "brightness", "%u", brightness);
if (r < 0)
return log_device_error_errno(device, r, "Failed to write system 'brightness' attribute: %m");
} else if (streq(argv[1], "save")) {
- const char *value;
-
if (validate_device(device) == 0) {
- unlink(saved);
+ (void) unlink(saved);
return 0;
}
- r = sd_device_get_sysattr_value(device, "brightness", &value);
+ r = read_brightness(device, max_brightness, &brightness);
if (r < 0)
- return log_device_error_errno(device, r, "Failed to read system 'brightness' attribute: %m");
+ return log_device_error_errno(device, r, "Failed to read current brightness: %m");
- r = write_string_file(saved, value, WRITE_STRING_FILE_CREATE);
+ r = write_string_filef(saved, WRITE_STRING_FILE_CREATE, "%u", brightness);
if (r < 0)
return log_device_error_errno(device, r, "Failed to write %s: %m", saved);
- } else {
- log_error("Unknown verb %s.", argv[1]);
- return -EINVAL;
- }
+ } else
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown verb %s.", argv[1]);
return 0;
}
projects / thirdparty / systemd.git / blobdiff