power_supply: add SCOPE attribute to power supplies

This adds a "scope" attribute to a power_supply, which indicates how
much of the system it powers.  It appears in sysfs as "scope" or in
the uevent file as POWER_SUPPLY_SCOPE=.  There are presently three
possible values:
	Unknown - unknown power topology
	System - the power supply powers the whole system
	Device - it powers a specific device, or tree of devices

A power supply which doesn't have a "scope" attribute should be assumed to
have "System" scope.

In general, usermode should assume that loss of all System-scoped power
supplies will power off the whole system, but any single one is sufficient
to power the system.

Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Richard Hughes <richard@hughsie.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 204c18dfdc9e..040a7b08e7c7 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -74,6 +74,12 @@ enum {
         POWER_SUPPLY_CAPACITY_LEVEL_FULL,
 };
 
+enum {
+        POWER_SUPPLY_SCOPE_UNKNOWN = 0,
+        POWER_SUPPLY_SCOPE_SYSTEM,
+        POWER_SUPPLY_SCOPE_DEVICE,
+};
+
 enum power_supply_property {
         /* Properties of type `int' */
         POWER_SUPPLY_PROP_STATUS = 0,
@@ -116,6 +122,7 @@ enum power_supply_property {
         POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
         POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
         POWER_SUPPLY_PROP_TYPE, /* use power_supply.type instead */
+        POWER_SUPPLY_PROP_SCOPE,
         /* Properties of type `const char *' */
         POWER_SUPPLY_PROP_MODEL_NAME,
         POWER_SUPPLY_PROP_MANUFACTURER,