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Diffstat (limited to 'src/backlight/backlight.c')
| -rw-r--r-- | src/backlight/backlight.c | 434 |
1 files changed, 0 insertions, 434 deletions
diff --git a/src/backlight/backlight.c b/src/backlight/backlight.c deleted file mode 100644 index 7c59f60d5f..0000000000 --- a/src/backlight/backlight.c +++ /dev/null @@ -1,434 +0,0 @@ -/*** - 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 "libudev.h" - -#include "alloc-util.h" -#include "def.h" -#include "escape.h" -#include "fileio.h" -#include "mkdir.h" -#include "parse-util.h" -#include "proc-cmdline.h" -#include "string-util.h" -#include "udev-util.h" -#include "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, DIGITS); - 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 = 0; - - 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 (!STRPTR_IN_SET(v, "platform", "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 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 device %s is a platform device and takes precedence.", - udev_device_get_sysname(device), - udev_device_get_sysname(other)); - return false; - } - } - - return true; -} - -static unsigned get_max_brightness(struct udev_device *device) { - int r; - const char *max_brightness_str; - unsigned max_brightness; - - max_brightness_str = udev_device_get_sysattr_value(device, "max_brightness"); - if (!max_brightness_str) { - log_warning("Failed to read 'max_brightness' attribute."); - return 0; - } - - r = safe_atou(max_brightness_str, &max_brightness); - if (r < 0) { - log_warning_errno(r, "Failed to parse 'max_brightness' \"%s\": %m", max_brightness_str); - return 0; - } - - if (max_brightness <= 0) { - log_warning("Maximum brightness is 0, ignoring device."); - return 0; - } - - return max_brightness; -} - -/* Some systems turn the backlight all the way off at the lowest levels. - * clamp_brightness clamps the saved brightness to at least 1 or 5% of - * 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 void clamp_brightness(struct udev_device *device, char **value, unsigned max_brightness) { - int r; - unsigned brightness, new_brightness, min_brightness; - const char *subsystem; - - r = safe_atou(*value, &brightness); - if (r < 0) { - log_warning_errno(r, "Failed to parse brightness \"%s\": %m", *value); - return; - } - - subsystem = udev_device_get_subsystem(device); - if (streq_ptr(subsystem, "backlight")) - min_brightness = MAX(1U, max_brightness/20); - else - min_brightness = 0; - - new_brightness = CLAMP(brightness, min_brightness, max_brightness); - if (new_brightness != brightness) { - char *old_value = *value; - - r = asprintf(value, "%u", new_brightness); - if (r < 0) { - log_oom(); - return; - } - - log_info("Saved brightness %s %s to %s.", old_value, - new_brightness > brightness ? - "too low; increasing" : "too high; decreasing", - *value); - - free(old_value); - } -} - -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; - unsigned max_brightness; - 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_errno(r, "Failed to create backlight directory /var/lib/systemd/backlight: %m"); - return EXIT_FAILURE; - } - - udev = udev_new(); - if (!udev) { - log_oom(); - return EXIT_FAILURE; - } - - sysname = strchr(argv[2], ':'); - if (!sysname) { - log_error("Requires a subsystem and sysname pair specifying a 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_errno(errno, "Failed to get backlight or LED device '%s:%s': %m", ss, sysname); - else - log_oom(); - - return EXIT_FAILURE; - } - - /* 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. - */ - max_brightness = get_max_brightness(device); - if (max_brightness == 0) - return EXIT_SUCCESS; - - 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")) { - _cleanup_free_ char *value = NULL; - const char *clamp; - - if (shall_restore_state() == 0) - return EXIT_SUCCESS; - - 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_errno(r, "Failed to read %s: %m", saved); - return EXIT_FAILURE; - } - - clamp = udev_device_get_property_value(device, "ID_BACKLIGHT_CLAMP"); - if (!clamp || parse_boolean(clamp) != 0) /* default to clamping */ - clamp_brightness(device, &value, max_brightness); - - r = udev_device_set_sysattr_value(device, "brightness", value); - if (r < 0) { - log_error_errno(r, "Failed to write system 'brightness' attribute: %m"); - 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 'brightness' attribute"); - return EXIT_FAILURE; - } - - r = write_string_file(saved, value, WRITE_STRING_FILE_CREATE); - if (r < 0) { - log_error_errno(r, "Failed to write %s: %m", saved); - return EXIT_FAILURE; - } - - } else { - log_error("Unknown verb %s.", argv[1]); - return EXIT_FAILURE; - } - - return EXIT_SUCCESS; -} |