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>
diff --git a/drivers/power/power_supply_sysfs.c b/drivers/power/power_supply_sysfs.c
index e15d4c9..21178eb 100644
--- a/drivers/power/power_supply_sysfs.c
+++ b/drivers/power/power_supply_sysfs.c
@@ -63,6 +63,9 @@
static char *capacity_level_text[] = {
"Unknown", "Critical", "Low", "Normal", "High", "Full"
};
+ static char *scope_text[] = {
+ "Unknown", "System", "Device"
+ };
ssize_t ret = 0;
struct power_supply *psy = dev_get_drvdata(dev);
const ptrdiff_t off = attr - power_supply_attrs;
@@ -95,6 +98,8 @@
return sprintf(buf, "%s\n", capacity_level_text[value.intval]);
else if (off == POWER_SUPPLY_PROP_TYPE)
return sprintf(buf, "%s\n", type_text[value.intval]);
+ else if (off == POWER_SUPPLY_PROP_SCOPE)
+ return sprintf(buf, "%s\n", scope_text[value.intval]);
else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
return sprintf(buf, "%s\n", value.strval);
@@ -167,6 +172,7 @@
POWER_SUPPLY_ATTR(time_to_full_now),
POWER_SUPPLY_ATTR(time_to_full_avg),
POWER_SUPPLY_ATTR(type),
+ POWER_SUPPLY_ATTR(scope),
/* Properties of type `const char *' */
POWER_SUPPLY_ATTR(model_name),
POWER_SUPPLY_ATTR(manufacturer),