power_supply: allow a power supply to explicitly point to powered device
If a power supply has a scope of "Device", then allow the power supply
to indicate what device it actually powers. This is represented in the
power supply's sysfs directory as a symlink named "powers", which points to
the sysfs directory of the powered device.
If the device has children, then the sub-devices are also powered by
the same power supply.
Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Richard Hughes <richard@hughsie.com>
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index 329b46b..b10c121 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -147,6 +147,12 @@
}
EXPORT_SYMBOL_GPL(power_supply_get_by_name);
+int power_supply_powers(struct power_supply *psy, struct device *dev)
+{
+ return sysfs_create_link_nowarn(&psy->dev->kobj, &dev->kobj, "powers");
+}
+EXPORT_SYMBOL_GPL(power_supply_powers);
+
static void power_supply_dev_release(struct device *dev)
{
pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
@@ -202,6 +208,7 @@
void power_supply_unregister(struct power_supply *psy)
{
cancel_work_sync(&psy->changed_work);
+ sysfs_remove_link(&psy->dev->kobj, "powers");
power_supply_remove_triggers(psy);
device_unregister(psy->dev);
}
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 040a7b0..2e3c827 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -218,6 +218,7 @@
extern int power_supply_register(struct device *parent,
struct power_supply *psy);
extern void power_supply_unregister(struct power_supply *psy);
+extern int power_supply_powers(struct power_supply *psy, struct device *dev);
/* For APM emulation, think legacy userspace. */
extern struct class *power_supply_class;