Merging upstream version 256.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 237 insertions, 180 deletions

diff --git a/src/backlight/backlight.c b/src/backlight/backlight.c
index b2032ad..2de6c20 100644
--- a/src/backlight/backlight.c
+++ b/src/backlight/backlight.c
@@ -11,7 +11,6 @@
 #include "escape.h"
 #include "fileio.h"
 #include "main-func.h"
-#include "mkdir.h"
 #include "parse-util.h"
 #include "percent-util.h"
 #include "pretty-print.h"
@@ -20,6 +19,7 @@
 #include "string-util.h"
 #include "strv.h"
 #include "terminal-util.h"
+#include "verbs.h"
 
 #define PCI_CLASS_GRAPHICS_CARD 0x30000
 
@@ -91,8 +91,8 @@ static int has_multiple_graphics_cards(void) {
 }
 
 static int find_pci_or_platform_parent(sd_device *device, sd_device **ret) {
-        const char *subsystem, *sysname, *value;
         sd_device *parent;
+        const char *s;
         int r;
 
         assert(device);
@@ -102,34 +102,29 @@ static int find_pci_or_platform_parent(sd_device *device, sd_device **ret) {
         if (r < 0)
                 return r;
 
-        r = sd_device_get_subsystem(parent, &subsystem);
-        if (r < 0)
-                return r;
-
-        r = sd_device_get_sysname(parent, &sysname);
-        if (r < 0)
-                return r;
+        if (device_in_subsystem(parent, "drm")) {
 
-        if (streq(subsystem, "drm")) {
-                const char *c;
+                r = sd_device_get_sysname(parent, &s);
+                if (r < 0)
+                        return r;
 
-                c = startswith(sysname, "card");
-                if (!c)
+                s = startswith(s, "card");
+                if (!s)
                         return -ENODATA;
 
-                c += strspn(c, DIGITS);
-                if (*c == '-' && !STARTSWITH_SET(c, "-LVDS-", "-Embedded DisplayPort-", "-eDP-"))
+                s += strspn(s, DIGITS);
+                if (*s == '-' && !STARTSWITH_SET(s, "-LVDS-", "-Embedded DisplayPort-", "-eDP-"))
                         /* A connector DRM device, let's ignore all but LVDS and eDP! */
                         return -EOPNOTSUPP;
 
-        } else if (streq(subsystem, "pci") &&
-                   sd_device_get_sysattr_value(parent, "class", &value) >= 0) {
+        } else if (device_in_subsystem(parent, "pci") &&
+                   sd_device_get_sysattr_value(parent, "class", &s)) {
+
                 unsigned long class;
 
-                r = safe_atolu(value, &class);
+                r = safe_atolu(s, &class);
                 if (r < 0)
-                        return log_warning_errno(r, "Cannot parse PCI class '%s' of device %s:%s: %m",
-                                                 value, subsystem, sysname);
+                        return log_device_warning_errno(parent, r, "Cannot parse PCI class '%s': %m", s);
 
                 /* Graphics card */
                 if (class == PCI_CLASS_GRAPHICS_CARD) {
@@ -137,7 +132,7 @@ static int find_pci_or_platform_parent(sd_device *device, sd_device **ret) {
                         return 0;
                 }
 
-        } else if (streq(subsystem, "platform")) {
+        } else if (device_in_subsystem(parent, "platform")) {
                 *ret = parent;
                 return 0;
         }
@@ -176,7 +171,7 @@ static int same_device(sd_device *a, sd_device *b) {
 
 static int validate_device(sd_device *device) {
         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *enumerate = NULL;
-        const char *v, *sysname, *subsystem;
+        const char *v, *sysname;
         sd_device *parent;
         int r;
 
@@ -184,7 +179,7 @@ static int validate_device(sd_device *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
+         * (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
@@ -195,11 +190,8 @@ static int validate_device(sd_device *device) {
         if (r < 0)
                 return log_device_debug_errno(device, r, "Failed to get sysname: %m");
 
-        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"))
-                return true;
+        if (!device_in_subsystem(device, "backlight"))
+                return true; /* We assume LED device is always valid. */
 
         r = sd_device_get_sysattr_value(device, "type", &v);
         if (r < 0)
@@ -211,15 +203,12 @@ static int validate_device(sd_device *device) {
         if (r < 0)
                 return log_device_debug_errno(device, r, "Failed to find PCI or platform parent: %m");
 
-        r = sd_device_get_subsystem(parent, &subsystem);
-        if (r < 0)
-                return log_device_debug_errno(parent, r, "Failed to get subsystem: %m");
-
         if (DEBUG_LOGGING) {
-                const char *s = NULL;
+                const char *s = NULL, *subsystem = NULL;
 
                 (void) sd_device_get_syspath(parent, &s);
-                log_device_debug(device, "Found %s parent device: %s", subsystem, strna(s));
+                (void) sd_device_get_subsystem(parent, &subsystem);
+                log_device_debug(device, "Found %s parent device: %s", strna(subsystem), strna(s));
         }
 
         r = sd_device_enumerator_new(&enumerate);
@@ -246,7 +235,7 @@ static int validate_device(sd_device *device) {
         if (r < 0)
                 return log_debug_errno(r, "Failed to add sysattr match: %m");
 
-        if (streq(subsystem, "pci")) {
+        if (device_in_subsystem(parent, "pci")) {
                 r = has_multiple_graphics_cards();
                 if (r < 0)
                         return log_debug_errno(r, "Failed to check if the system has multiple graphics cards: %m");
@@ -254,8 +243,8 @@ static int validate_device(sd_device *device) {
                         /* If the system has multiple graphics cards, then we cannot associate platform
                          * devices on non-PCI bus (especially WMI bus) with PCI devices. Let's ignore all
                          * backlight devices that do not have the same parent PCI device. */
-                        log_debug("Found multiple graphics cards on PCI bus. "
-                                  "Skipping to associate platform backlight devices on non-PCI bus.");
+                        log_debug("Found multiple graphics cards on PCI bus; "
+                                  "skipping deduplication of platform backlight devices not on PCI bus.");
 
                         r = sd_device_enumerator_add_match_parent(enumerate, parent);
                         if (r < 0)
@@ -264,7 +253,6 @@ static int validate_device(sd_device *device) {
         }
 
         FOREACH_DEVICE(enumerate, other) {
-                const char *other_subsystem;
                 sd_device *other_parent;
 
                 /* OK, so there's another backlight device, and it's a platform or firmware device.
@@ -289,13 +277,7 @@ static int validate_device(sd_device *device) {
                         return false;
                 }
 
-                r = sd_device_get_subsystem(other_parent, &other_subsystem);
-                if (r < 0) {
-                        log_device_debug_errno(other_parent, r, "Failed to get subsystem, ignoring: %m");
-                        continue;
-                }
-
-                if (streq(other_subsystem, "platform") && streq(subsystem, "pci")) {
+                if (device_in_subsystem(other_parent, "platform") && device_in_subsystem(parent, "pci")) {
                         /* The other is connected to the platform bus and we are a PCI device, that also means we are out. */
                         if (DEBUG_LOGGING) {
                                 const char *other_sysname = NULL, *other_type = NULL;
@@ -313,7 +295,8 @@ static int validate_device(sd_device *device) {
         return true;
 }
 
-static int get_max_brightness(sd_device *device, unsigned *ret) {
+static int read_max_brightness(sd_device *device, unsigned *ret) {
+        unsigned max_brightness;
         const char *s;
         int r;
 
@@ -324,11 +307,22 @@ static int get_max_brightness(sd_device *device, unsigned *ret) {
         if (r < 0)
                 return log_device_warning_errno(device, r, "Failed to read 'max_brightness' attribute: %m");
 
-        r = safe_atou(s, ret);
+        r = safe_atou(s, &max_brightness);
         if (r < 0)
                 return log_device_warning_errno(device, r, "Failed to parse 'max_brightness' \"%s\": %m", s);
 
-        return 0;
+        /* If max_brightness is 0, then there is no actual backlight device. This happens on desktops
+         * with Asus mainboards that load the eeepc-wmi module. */
+        if (max_brightness == 0) {
+                log_device_warning(device, "Maximum brightness is 0, ignoring device.");
+                *ret = 0;
+                return 0;
+        }
+
+        log_device_debug(device, "Maximum brightness is %u", max_brightness);
+
+        *ret = max_brightness;
+        return 1; /* valid max brightness */
 }
 
 static int clamp_brightness(
@@ -339,8 +333,6 @@ static int clamp_brightness(
                 unsigned *brightness) {
 
         unsigned new_brightness, min_brightness;
-        const char *subsystem;
-        int r;
 
         assert(device);
         assert(brightness);
@@ -350,14 +342,9 @@ static int clamp_brightness(
          * avoids preserving an unreadably dim screen, which would otherwise force the user to disable
          * state restoration. */
 
-        r = sd_device_get_subsystem(device, &subsystem);
-        if (r < 0)
-                return log_device_warning_errno(device, r, "Failed to get device subsystem: %m");
-
-        if (streq(subsystem, "backlight"))
-                min_brightness = MAX(1U, (unsigned) ((double) max_brightness * percent / 100));
-        else
-                min_brightness = 0;
+        min_brightness = (unsigned) ((double) max_brightness * percent / 100);
+        if (device_in_subsystem(device, "backlight"))
+                min_brightness = MAX(1U, min_brightness);
 
         new_brightness = CLAMP(*brightness, min_brightness, max_brightness);
         if (new_brightness != *brightness)
@@ -372,19 +359,28 @@ static int clamp_brightness(
         return 0;
 }
 
-static bool shall_clamp(sd_device *d, unsigned *ret) {
-        const char *s;
+static bool shall_clamp(sd_device *device, unsigned *ret) {
+        const char *property, *s;
+        unsigned default_percent;
         int r;
 
-        assert(d);
+        assert(device);
         assert(ret);
 
-        r = sd_device_get_property_value(d, "ID_BACKLIGHT_CLAMP", &s);
+        if (device_in_subsystem(device, "backlight")) {
+                property = "ID_BACKLIGHT_CLAMP";
+                default_percent = 5;
+        } else {
+                property = "ID_LEDS_CLAMP";
+                default_percent = 0;
+        }
+
+        r = sd_device_get_property_value(device, property, &s);
         if (r < 0) {
                 if (r != -ENOENT)
-                        log_device_debug_errno(d, r, "Failed to get ID_BACKLIGHT_CLAMP property, ignoring: %m");
-                *ret = 5; /* defaults to 5% */
-                return true;
+                        log_device_debug_errno(device, r, "Failed to get %s property, ignoring: %m", property);
+                *ret = default_percent;
+                return default_percent > 0;
         }
 
         r = parse_boolean(s);
@@ -395,9 +391,9 @@ static bool shall_clamp(sd_device *d, unsigned *ret) {
 
         r = parse_percent(s);
         if (r < 0) {
-                log_device_debug_errno(d, r, "Failed to parse ID_BACKLIGHT_CLAMP property, ignoring: %m");
-                *ret = 5;
-                return true;
+                log_device_debug_errno(device, r, "Failed to parse %s property, ignoring: %m", property);
+                *ret = default_percent;
+                return default_percent > 0;
         }
 
         *ret = r;
@@ -405,18 +401,14 @@ static bool shall_clamp(sd_device *d, unsigned *ret) {
 }
 
 static int read_brightness(sd_device *device, unsigned max_brightness, unsigned *ret_brightness) {
-        const char *subsystem, *value;
+        const char *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")) {
+        if (device_in_subsystem(device, "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, "
@@ -463,154 +455,219 @@ use_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, brightness;
+static int build_save_file_path(sd_device *device, char **ret) {
+        _cleanup_free_ char *escaped_subsystem = NULL, *escaped_sysname = NULL, *path = NULL;
+        const char *s;
         int r;
 
-        log_setup();
+        assert(device);
+        assert(ret);
 
-        if (argv_looks_like_help(argc, argv))
-                return help();
+        r = sd_device_get_subsystem(device, &s);
+        if (r < 0)
+                return log_device_error_errno(device, r, "Failed to get subsystem: %m");
 
-        if (argc != 3)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program requires two arguments.");
+        escaped_subsystem = cescape(s);
+        if (!escaped_subsystem)
+                return log_oom();
 
-        if (!STR_IN_SET(argv[1], "load", "save"))
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown verb %s.", argv[1]);
+        r = sd_device_get_sysname(device, &s);
+        if (r < 0)
+                return log_device_error_errno(device, r, "Failed to get sysname: %m");
 
-        umask(0022);
+        escaped_sysname = cescape(s);
+        if (!escaped_sysname)
+                return log_oom();
 
-        r = mkdir_p("/var/lib/systemd/backlight", 0755);
-        if (r < 0)
-                return log_error_errno(r, "Failed to create backlight directory /var/lib/systemd/backlight: %m");
+        if (sd_device_get_property_value(device, "ID_PATH", &s) >= 0) {
+                _cleanup_free_ char *escaped_path_id = cescape(s);
+                if (!escaped_path_id)
+                        return log_oom();
 
-        sysname = strchr(argv[2], ':');
-        if (!sysname)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Requires a subsystem and sysname pair specifying a backlight device.");
+                path = strjoin("/var/lib/systemd/backlight/", escaped_path_id, ":", escaped_subsystem, ":", escaped_sysname);
+        } else
+                path = strjoin("/var/lib/systemd/backlight/", escaped_subsystem, ":", escaped_sysname);
+        if (!path)
+                return log_oom();
 
-        ss = strndupa_safe(argv[2], sysname - argv[2]);
+        *ret = TAKE_PTR(path);
+        return 0;
+}
 
-        sysname++;
+static int read_saved_brightness(sd_device *device, unsigned *ret) {
+        _cleanup_free_ char *path = NULL, *value = NULL;
+        int r;
 
-        if (!STR_IN_SET(ss, "backlight", "leds"))
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Not a backlight or LED device: '%s:%s'", ss, sysname);
+        assert(device);
+        assert(ret);
+
+        r = build_save_file_path(device, &path);
+        if (r < 0)
+                return r;
 
-        r = sd_device_new_from_subsystem_sysname(&device, ss, sysname);
+        r = read_one_line_file(path, &value);
         if (r < 0) {
-                bool ignore = r == -ENODEV;
+                if (r != -ENOENT)
+                        log_device_error_errno(device, r, "Failed to read %s: %m", path);
+                return r;
+        }
 
-                /* Some drivers, e.g. for AMD GPU, removes acpi backlight device soon after it is added.
-                 * See issue #21997. */
-                log_full_errno(ignore ? LOG_DEBUG : LOG_ERR, r,
-                               "Failed to get backlight or LED device '%s:%s'%s: %m",
-                               ss, sysname, ignore ? ", ignoring" : "");
-                return ignore ? 0 : r;
+        r = safe_atou(value, ret);
+        if (r < 0) {
+                log_device_warning_errno(device, r,
+                                         "Failed to parse saved brightness '%s', removing %s.",
+                                         value, path);
+                (void) unlink(path);
+                return r;
         }
 
-        /* If max_brightness is 0, then there is no actual backlight device. This happens on desktops
-         * with Asus mainboards that load the eeepc-wmi module. */
-        if (get_max_brightness(device, &max_brightness) < 0)
-                return 0;
+        log_device_debug(device, "Using saved brightness %u.", *ret);
+        return 0;
+}
 
-        if (max_brightness == 0) {
-                log_device_warning(device, "Maximum brightness is 0, ignoring device.");
-                return 0;
-        }
+static int device_new_from_arg(const char *s, sd_device **ret) {
+        _cleanup_(sd_device_unrefp) sd_device *device = NULL;
+        _cleanup_free_ char *subsystem = NULL;
+        const char *sysname;
+        int r;
 
-        log_device_debug(device, "Maximum brightness is %u", max_brightness);
+        assert(s);
+        assert(ret);
 
-        escaped_ss = cescape(ss);
-        if (!escaped_ss)
-                return log_oom();
+        sysname = strchr(s, ':');
+        if (!sysname)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Requires a subsystem and sysname pair specifying a backlight or LED device.");
 
-        escaped_sysname = cescape(sysname);
-        if (!escaped_sysname)
+        subsystem = strndup(s, sysname - s);
+        if (!subsystem)
                 return log_oom();
 
-        if (sd_device_get_property_value(device, "ID_PATH", &path_id) >= 0) {
-                escaped_path_id = cescape(path_id);
-                if (!escaped_path_id)
-                        return log_oom();
+        sysname++;
 
-                saved = strjoina("/var/lib/systemd/backlight/", escaped_path_id, ":", escaped_ss, ":", escaped_sysname);
-        } else
-                saved = strjoina("/var/lib/systemd/backlight/", escaped_ss, ":", escaped_sysname);
+        if (!STR_IN_SET(subsystem, "backlight", "leds"))
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Not a backlight or LED device: '%s:%s'",
+                                       subsystem, sysname);
 
-        /* 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. */
+        r = sd_device_new_from_subsystem_sysname(&device, subsystem, sysname);
+        if (r == -ENODEV) {
+                /* Some drivers, e.g. for AMD GPU, removes acpi backlight device soon after it is added.
+                 * See issue #21997. */
+                log_debug_errno(r, "Failed to get backlight or LED device '%s:%s', ignoring: %m", subsystem, sysname);
+                *ret = NULL;
+                return 0;
+        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to get backlight or LED device '%s:%s': %m", subsystem, sysname);
 
-        if (streq(argv[1], "load")) {
-                _cleanup_free_ char *value = NULL;
-                unsigned percent;
-                bool clamp;
+        *ret = TAKE_PTR(device);
+        return 1; /* Found. */
+}
 
-                if (!shall_restore_state())
-                        return 0;
+static int verb_load(int argc, char *argv[], void *userdata) {
+        _cleanup_(sd_device_unrefp) sd_device *device = NULL;
+        unsigned max_brightness, brightness, percent;
+        bool clamp;
+        int r;
 
-                if (validate_device(device) == 0)
-                        return 0;
+        assert(argc == 2);
 
-                clamp = shall_clamp(device, &percent);
+        if (!shall_restore_state())
+                return 0;
 
-                r = read_one_line_file(saved, &value);
-                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_warning_errno(r, "Failed to parse saved brightness '%s', removing %s.",
-                                                  value, saved);
-                                (void) unlink(saved);
-                        } else {
-                                log_debug("Using saved brightness %u.", brightness);
-                                if (clamp)
-                                        (void) clamp_brightness(device, percent, /* saved = */ 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 = device_new_from_arg(argv[1], &device);
+        if (r <= 0)
+                return r;
 
-                        r = read_brightness(device, max_brightness, &brightness);
-                        if (r < 0)
-                                return log_device_error_errno(device, r, "Failed to read current brightness: %m");
+        r = read_max_brightness(device, &max_brightness);
+        if (r <= 0)
+                return r;
 
-                        (void) clamp_brightness(device, percent, /* saved = */ false, max_brightness, &brightness);
-                }
+        /* Ignore any errors in validation, and use the device as is. */
+        if (validate_device(device) == 0)
+                return 0;
 
-                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");
+        clamp = shall_clamp(device, &percent);
 
-        } else if (streq(argv[1], "save")) {
-                if (validate_device(device) == 0) {
-                        (void) unlink(saved);
+        r = read_saved_brightness(device, &brightness);
+        if (r < 0) {
+                /* Fallback to clamping current brightness or exit early if clamping is not
+                 * supported/enabled. */
+                if (!clamp)
                         return 0;
-                }
 
                 r = read_brightness(device, max_brightness, &brightness);
                 if (r < 0)
                         return log_device_error_errno(device, r, "Failed to read current brightness: %m");
 
-                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);
+                (void) clamp_brightness(device, percent, /* saved = */ false, max_brightness, &brightness);
+        } else if (clamp)
+                (void) clamp_brightness(device, percent, /* saved = */ true, max_brightness, &brightness);
 
-        } else
-                assert_not_reached();
+        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");
+
+        return 0;
+}
+
+static int verb_save(int argc, char *argv[], void *userdata) {
+        _cleanup_(sd_device_unrefp) sd_device *device = NULL;
+        _cleanup_free_ char *path = NULL;
+        unsigned max_brightness, brightness;
+        int r;
+
+        assert(argc == 2);
+
+        r = device_new_from_arg(argv[1], &device);
+        if (r <= 0)
+                return r;
+
+        r = read_max_brightness(device, &max_brightness);
+        if (r <= 0)
+                return r;
+
+        r = build_save_file_path(device, &path);
+        if (r < 0)
+                return r;
+
+        /* 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 (validate_device(device) == 0) {
+                (void) unlink(path);
+                return 0;
+        }
+
+        r = read_brightness(device, max_brightness, &brightness);
+        if (r < 0)
+                return log_device_error_errno(device, r, "Failed to read current brightness: %m");
+
+        r = write_string_filef(path, WRITE_STRING_FILE_CREATE | WRITE_STRING_FILE_MKDIR_0755, "%u", brightness);
+        if (r < 0)
+                return log_device_error_errno(device, r, "Failed to write %s: %m", path);
 
         return 0;
 }
 
+static int run(int argc, char *argv[]) {
+        static const Verb verbs[] = {
+                { "load", 2, 2, VERB_ONLINE_ONLY, verb_load },
+                { "save", 2, 2, VERB_ONLINE_ONLY, verb_save },
+                {}
+        };
+
+        log_setup();
+
+        if (argv_looks_like_help(argc, argv))
+                return help();
+
+        umask(0022);
+
+        return dispatch_verb(argc, argv, verbs, NULL);
+}
+
 DEFINE_MAIN_FUNCTION(run);