power: supply: core: Add support for supplied-from device-property

On devicetree using platforms the devicetree can provide info on which
power-supplies supply another power-supply through phandles.

This commit adds support for providing this info on non devicetree
platforms through the platform code setting a supplied-from
device-property on the power-supplies parent device.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index 7ec7c7c..0c09144 100644 (file)
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -274,8 +274,30 @@ static int power_supply_check_supplies(struct power_supply *psy)
        return power_supply_populate_supplied_from(psy);
 }
 #else
-static inline int power_supply_check_supplies(struct power_supply *psy)
+static int power_supply_check_supplies(struct power_supply *psy)
 {
+       int nval, ret;
+
+       if (!psy->dev.parent)
+               return 0;
+
+       nval = device_property_read_string_array(psy->dev.parent,
+                                                "supplied-from", NULL, 0);
+       if (nval <= 0)
+               return 0;
+
+       psy->supplied_from = devm_kmalloc_array(&psy->dev, nval,
+                                               sizeof(char *), GFP_KERNEL);
+       if (!psy->supplied_from)
+               return -ENOMEM;
+
+       ret = device_property_read_string_array(psy->dev.parent,
+               "supplied-from", (const char **)psy->supplied_from, nval);
+       if (ret < 0)
+               return ret;
+
+       psy->num_supplies = nval;
+
        return 0;
 }
 #endif