power_supply: Add core support for supplied_from

This patch adds support for supplies to register a list of char *'s which
represent the list of supplies which supply them. This is the opposite as
the supplied_to list.

This change maintains support for supplied_to until all drivers which make
use of it already are converted.

Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

1 files changed, 34 insertions, 13 deletions

diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index 5deac432e2ae..d843cc9df030 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -26,17 +26,42 @@ EXPORT_SYMBOL_GPL(power_supply_class);
 
 static struct device_type power_supply_dev_type;
 
+static bool __power_supply_is_supplied_by(struct power_supply *supplier,
+                                         struct power_supply *supply)
+{
+        int i;
+
+        if (!supply->supplied_from && !supplier->supplied_to)
+                return false;
+
+        /* Support both supplied_to and supplied_from modes */
+        if (supply->supplied_from) {
+                if (!supplier->name)
+                        return false;
+                for (i = 0; i < supply->num_supplies; i++)
+                        if (!strcmp(supplier->name, supply->supplied_from[i]))
+                                return true;
+        } else {
+                if (!supply->name)
+                        return false;
+                for (i = 0; i < supplier->num_supplicants; i++)
+                        if (!strcmp(supplier->supplied_to[i], supply->name))
+                                return true;
+        }
+
+        return false;
+}
+
 static int __power_supply_changed_work(struct device *dev, void *data)
 {
         struct power_supply *psy = (struct power_supply *)data;
         struct power_supply *pst = dev_get_drvdata(dev);
-        int i;
 
-        for (i = 0; i < psy->num_supplicants; i++)
-                if (!strcmp(psy->supplied_to[i], pst->name)) {
-                        if (pst->external_power_changed)
-                                pst->external_power_changed(pst);
-                }
+        if (__power_supply_is_supplied_by(psy, pst)) {
+                if (pst->external_power_changed)
+                        pst->external_power_changed(pst);
+        }
+
         return 0;
 }
 
@@ -68,17 +93,13 @@ static int __power_supply_am_i_supplied(struct device *dev, void *data)
         union power_supply_propval ret = {0,};
         struct power_supply *psy = (struct power_supply *)data;
         struct power_supply *epsy = dev_get_drvdata(dev);
-        int i;
 
-        for (i = 0; i < epsy->num_supplicants; i++) {
-                if (!strcmp(epsy->supplied_to[i], psy->name)) {
-                        if (epsy->get_property(epsy,
-                                  POWER_SUPPLY_PROP_ONLINE, &ret))
-                                continue;
+        if (__power_supply_is_supplied_by(epsy, psy))
+                if (!epsy->get_property(epsy, POWER_SUPPLY_PROP_ONLINE, &ret)) {
                         if (ret.intval)
                                 return ret.intval;
                 }
-        }
+
         return 0;
 }