[PATCH v2 1/9] power: supply: core: Add power_supply_has_property_direct()

[Armin Wolf <W_Armin@gmx.de>]

Providers of power supply extensions might want to check if a given
power supply supports a given property in order to select a suitable
extension to load.

Add power_supply_has_property_direct() to enable such use cases.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
 drivers/power/supply/power_supply_core.c | 26 ++++++++++++++++++++----
 include/linux/power_supply.h             |  1 +
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index 1cc203f2780b..75b53aec5db4 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -1367,17 +1367,35 @@ bool power_supply_ext_has_property(const struct power_supply_ext *psy_ext,
 	return false;
 }
 
-bool power_supply_has_property(struct power_supply *psy,
-			       enum power_supply_property psp)
+/**
+ * power_supply_has_property_direct - Check if a power supply property exists without checking
+ *				      for extensions
+ * @psy: The power supply
+ * @psp: The power supply property to check
+ *
+ * Check if a given power supply support a given power supply property without taking into account
+ * any power supply extesions registered on said power supply. This is mostly useful for determining
+ * if a power supply extension should be registered for the power supply or not.
+ */
+bool power_supply_has_property_direct(struct power_supply *psy, enum power_supply_property psp)
 {
-	struct power_supply_ext_registration *reg;
-
 	if (psy_desc_has_property(psy->desc, psp))
 		return true;
 
 	if (power_supply_battery_info_has_prop(psy->battery_info, psp))
 		return true;
 
+	return false;
+}
+EXPORT_SYMBOL_GPL(power_supply_has_property_direct);
+
+bool power_supply_has_property(struct power_supply *psy, enum power_supply_property psp)
+{
+	struct power_supply_ext_registration *reg;
+
+	if (power_supply_has_property_direct(psy, psp))
+		return true;
+
 	power_supply_for_each_extension(reg, psy) {
 		if (power_supply_ext_has_property(reg->ext, psp))
 			return true;
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index cce61137aef4..73bcb127d0fc 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -934,6 +934,7 @@ extern int power_supply_is_system_supplied(void);
 static inline int power_supply_is_system_supplied(void) { return -ENOSYS; }
 #endif
 
+bool power_supply_has_property_direct(struct power_supply *psy, enum power_supply_property psp);
 extern int power_supply_get_property(struct power_supply *psy,
 			    enum power_supply_property psp,
 			    union power_supply_propval *val);
-- 
2.56.0