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-rw-r--r--src/shared/battery-util.c283
1 files changed, 283 insertions, 0 deletions
diff --git a/src/shared/battery-util.c b/src/shared/battery-util.c
new file mode 100644
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--- /dev/null
+++ b/src/shared/battery-util.c
@@ -0,0 +1,283 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "sd-device.h"
+
+#include "device-private.h"
+#include "device-util.h"
+#include "string-util.h"
+#include "battery-util.h"
+
+#define BATTERY_LOW_CAPACITY_LEVEL 5
+
+static int device_is_power_sink(sd_device *device) {
+ _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
+ bool found_source = false, found_sink = false;
+ sd_device *parent;
+ int r;
+
+ assert(device);
+
+ /* USB-C power supply device has two power roles: source or sink. See,
+ * https://docs.kernel.org/admin-guide/abi-testing.html#abi-file-testing-sysfs-class-typec */
+
+ r = sd_device_enumerator_new(&e);
+ if (r < 0)
+ return r;
+
+ r = sd_device_enumerator_allow_uninitialized(e);
+ if (r < 0)
+ return r;
+
+ r = sd_device_enumerator_add_match_subsystem(e, "typec", true);
+ if (r < 0)
+ return r;
+
+ r = sd_device_get_parent(device, &parent);
+ if (r < 0)
+ return r;
+
+ r = sd_device_enumerator_add_match_parent(e, parent);
+ if (r < 0)
+ return r;
+
+ FOREACH_DEVICE(e, d) {
+ const char *val;
+
+ r = sd_device_get_sysattr_value(d, "power_role", &val);
+ if (r < 0) {
+ if (r != -ENOENT)
+ log_device_debug_errno(d, r, "Failed to read 'power_role' sysfs attribute, ignoring: %m");
+ continue;
+ }
+
+ if (strstr(val, "[source]")) {
+ found_source = true;
+ log_device_debug(d, "The USB type-C port is in power source mode.");
+ } else if (strstr(val, "[sink]")) {
+ found_sink = true;
+ log_device_debug(d, "The USB type-C port is in power sink mode.");
+ }
+ }
+
+ if (found_sink)
+ log_device_debug(device, "The USB type-C device has at least one port in power sink mode.");
+ else if (!found_source)
+ log_device_debug(device, "The USB type-C device has no port in power source mode, assuming the device is in power sink mode.");
+ else
+ log_device_debug(device, "All USB type-C ports are in power source mode.");
+
+ return found_sink || !found_source;
+}
+
+static bool battery_is_discharging(sd_device *d) {
+ const char *val;
+ int r;
+
+ assert(d);
+
+ r = sd_device_get_sysattr_value(d, "scope", &val);
+ if (r < 0) {
+ if (r != -ENOENT)
+ log_device_debug_errno(d, r, "Failed to read 'scope' sysfs attribute, ignoring: %m");
+ } else if (streq(val, "Device")) {
+ log_device_debug(d, "The power supply is a device battery, ignoring device.");
+ return false;
+ }
+
+ r = device_get_sysattr_bool(d, "present");
+ if (r < 0)
+ log_device_debug_errno(d, r, "Failed to read 'present' sysfs attribute, assuming the battery is present: %m");
+ else if (r == 0) {
+ log_device_debug(d, "The battery is not present, ignoring the power supply.");
+ return false;
+ }
+
+ /* Possible values: "Unknown", "Charging", "Discharging", "Not charging", "Full" */
+ r = sd_device_get_sysattr_value(d, "status", &val);
+ if (r < 0) {
+ log_device_debug_errno(d, r, "Failed to read 'status' sysfs attribute, assuming the battery is discharging: %m");
+ return true;
+ }
+ if (!streq(val, "Discharging")) {
+ log_device_debug(d, "The battery status is '%s', assuming the battery is not used as a power source of this machine.", val);
+ return false;
+ }
+
+ return true;
+}
+
+int on_ac_power(void) {
+ _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
+ bool found_ac_online = false, found_discharging_battery = false;
+ int r;
+
+ r = sd_device_enumerator_new(&e);
+ if (r < 0)
+ return r;
+
+ r = sd_device_enumerator_allow_uninitialized(e);
+ if (r < 0)
+ return r;
+
+ r = sd_device_enumerator_add_match_subsystem(e, "power_supply", true);
+ if (r < 0)
+ return r;
+
+ FOREACH_DEVICE(e, d) {
+ /* See
+ * https://github.com/torvalds/linux/blob/4eef766b7d4d88f0b984781bc1bcb574a6eafdc7/include/linux/power_supply.h#L176
+ * for defined power source types. Also see:
+ * https://docs.kernel.org/admin-guide/abi-testing.html#abi-file-testing-sysfs-class-power */
+
+ const char *val;
+ r = sd_device_get_sysattr_value(d, "type", &val);
+ if (r < 0) {
+ log_device_debug_errno(d, r, "Failed to read 'type' sysfs attribute, ignoring device: %m");
+ continue;
+ }
+
+ /* Ignore USB-C power supply in source mode. See issue #21988. */
+ if (streq(val, "USB")) {
+ r = device_is_power_sink(d);
+ if (r <= 0) {
+ if (r < 0)
+ log_device_debug_errno(d, r, "Failed to determine the current power role, ignoring device: %m");
+ else
+ log_device_debug(d, "USB power supply is in source mode, ignoring device.");
+ continue;
+ }
+ }
+
+ if (streq(val, "Battery")) {
+ if (battery_is_discharging(d)) {
+ found_discharging_battery = true;
+ log_device_debug(d, "The power supply is a battery and currently discharging.");
+ }
+ continue;
+ }
+
+ r = device_get_sysattr_unsigned(d, "online", NULL);
+ if (r < 0) {
+ log_device_debug_errno(d, r, "Failed to query 'online' sysfs attribute, ignoring device: %m");
+ continue;
+ } else if (r > 0) /* At least 1 and 2 are defined as different types of 'online' */
+ found_ac_online = true;
+
+ log_device_debug(d, "The power supply is currently %s.", r > 0 ? "online" : "offline");
+ }
+
+ if (found_ac_online) {
+ log_debug("Found at least one online non-battery power supply, system is running on AC.");
+ return true;
+ } else if (found_discharging_battery) {
+ log_debug("Found at least one discharging battery and no online power sources, assuming system is running from battery.");
+ return false;
+ } else {
+ log_debug("No power supply reported online and no discharging battery found, assuming system is running on AC.");
+ return true;
+ }
+}
+
+/* Get the list of batteries */
+int battery_enumerator_new(sd_device_enumerator **ret) {
+ _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
+ int r;
+
+ assert(ret);
+
+ r = sd_device_enumerator_new(&e);
+ if (r < 0)
+ return r;
+
+ r = sd_device_enumerator_add_match_subsystem(e, "power_supply", /* match = */ true);
+ if (r < 0)
+ return r;
+
+ r = sd_device_enumerator_allow_uninitialized(e);
+ if (r < 0)
+ return r;
+
+ r = sd_device_enumerator_add_match_sysattr(e, "type", "Battery", /* match = */ true);
+ if (r < 0)
+ return r;
+
+ r = sd_device_enumerator_add_match_sysattr(e, "present", "1", /* match = */ true);
+ if (r < 0)
+ return r;
+
+ r = sd_device_enumerator_add_match_sysattr(e, "scope", "Device", /* match = */ false);
+ if (r < 0)
+ return r;
+
+ *ret = TAKE_PTR(e);
+ return 0;
+}
+
+/* Battery percentage capacity fetched from capacity file and if in range 0-100 then returned */
+int battery_read_capacity_percentage(sd_device *dev) {
+ int battery_capacity, r;
+
+ assert(dev);
+
+ r = device_get_sysattr_int(dev, "capacity", &battery_capacity);
+ if (r < 0)
+ return log_device_debug_errno(dev, r, "Failed to read/parse POWER_SUPPLY_CAPACITY: %m");
+
+ if (battery_capacity < 0 || battery_capacity > 100)
+ return log_device_debug_errno(dev, SYNTHETIC_ERRNO(ERANGE), "Invalid battery capacity: %d", battery_capacity);
+
+ return battery_capacity;
+}
+
+/* If a battery whose percentage capacity is <= 5% exists, and we're not on AC power, return success */
+int battery_is_discharging_and_low(void) {
+ _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
+ bool unsure = false, found_low = false;
+ int r;
+
+ /* We have not used battery capacity_level since value is set to full
+ * or Normal in case ACPI is not working properly. In case of no battery
+ * 0 will be returned and system will be suspended for 1st cycle then hibernated */
+
+ r = on_ac_power();
+ if (r < 0)
+ log_warning_errno(r, "Failed to check if the system is running on AC, assuming it is not: %m");
+ if (r > 0)
+ return false;
+
+ r = battery_enumerator_new(&e);
+ if (r < 0)
+ return log_error_errno(r, "Failed to initialize battery enumerator: %m");
+
+ FOREACH_DEVICE(e, dev) {
+ int level;
+
+ level = battery_read_capacity_percentage(dev);
+ if (level < 0) {
+ unsure = true;
+ continue;
+ }
+
+ if (level > BATTERY_LOW_CAPACITY_LEVEL) { /* Found a charged battery */
+ log_device_full(dev,
+ found_low ? LOG_INFO : LOG_DEBUG,
+ "Found battery with capacity above threshold (%d%% > %d%%).",
+ level, BATTERY_LOW_CAPACITY_LEVEL);
+ return false;
+ }
+
+ log_device_info(dev,
+ "Found battery with capacity below threshold (%d%% <= %d%%).",
+ level, BATTERY_LOW_CAPACITY_LEVEL);
+ found_low = true;
+ }
+
+ /* If we found a battery whose state we couldn't read, don't assume we are in low battery state */
+ if (unsure) {
+ log_notice("Found battery with unreadable state, assuming not in low battery state.");
+ return false;
+ }
+
+ /* If found neither charged nor low batteries, assume that we aren't in low battery state */
+ return found_low;
+}
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