[PATCH 12/18] power: supply: Add power_supply_set_input_current_limit_from_supplier helper

[Hans de Goede]

On some devices the USB Type-C port power (USB PD 2.0) negotiation is
done by a separate port-controller IC, while the current limit is
controlled through another (charger) IC.

It has been decided to model this by modelling the external Type-C
power brick (adapter/charger) as a power-supply class device which
supplies the charger-IC, with its voltage-now and current-max representing
the negotiated voltage and max current draw.

This commit adds a power_supply_set_input_current_limit_from_supplier
helper function which charger power-supply drivers can call to get
the max-current from their supplier and have this applied
through their set_property call-back to their input-current-limit.

Signed-off-by: Hans de Goede 
---
 drivers/power/supply/power_supply_core.c | 41 
 include/linux/power_supply.h |  2 ++
 2 files changed, 43 insertions(+)

diff --git a/drivers/power/supply/power_supply_core.c 
b/drivers/power/supply/power_supply_core.c
index 0741fcef3b44..3f92574222de 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -375,6 +375,47 @@ int power_supply_is_system_supplied(void)
 }
 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 
+static int __power_supply_get_supplier_max_current(struct device *dev,
+  void *data)
+{
+   union power_supply_propval ret = {0,};
+   struct power_supply *epsy = dev_get_drvdata(dev);
+   struct power_supply *psy = data;
+
+   if (__power_supply_is_supplied_by(epsy, psy))
+   if (!epsy->desc->get_property(epsy,
+ POWER_SUPPLY_PROP_CURRENT_MAX,
+ ))
+   return ret.intval;
+
+   return 0;
+}
+
+int power_supply_set_input_current_limit_from_supplier(struct power_supply 
*psy)
+{
+   union power_supply_propval val = {0,};
+   int curr;
+
+   if (!psy->desc->set_property)
+   return -EINVAL;
+
+   /*
+* This function is not intended for use with a supply with multiple
+* suppliers, we simply pick the first supply to report a non 0
+* max-current.
+*/
+   curr = class_for_each_device(power_supply_class, NULL, psy,
+ __power_supply_get_supplier_max_current);
+   if (curr <= 0)
+   return (curr == 0) ? -ENODEV : curr;
+
+   val.intval = curr;
+
+   return psy->desc->set_property(psy,
+   POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT, );
+}
+EXPORT_SYMBOL_GPL(power_supply_set_input_current_limit_from_supplier);
+
 int power_supply_set_battery_charged(struct power_supply *psy)
 {
if (atomic_read(>use_cnt) >= 0 &&
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index de89066b72b1..79e90b3d3288 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -332,6 +332,8 @@ extern int power_supply_get_battery_info(struct 
power_supply *psy,
 struct power_supply_battery_info 
*info);
 extern void power_supply_changed(struct power_supply *psy);
 extern int power_supply_am_i_supplied(struct power_supply *psy);
+extern int power_supply_set_input_current_limit_from_supplier(
+struct power_supply *psy);
 extern int power_supply_set_battery_charged(struct power_supply *psy);
 
 #ifdef CONFIG_POWER_SUPPLY
-- 
2.13.3

[PATCH 12/18] power: supply: Add power_supply_set_input_current_limit_from_supplier helper

[Hans de Goede]

On some devices the USB Type-C port power (USB PD 2.0) negotiation is
done by a separate port-controller IC, while the current limit is
controlled through another (charger) IC.

It has been decided to model this by modelling the external Type-C
power brick (adapter/charger) as a power-supply class device which
supplies the charger-IC, with its voltage-now and current-max representing
the negotiated voltage and max current draw.

This commit adds a power_supply_set_input_current_limit_from_supplier
helper function which charger power-supply drivers can call to get
the max-current from their supplier and have this applied
through their set_property call-back to their input-current-limit.

Signed-off-by: Hans de Goede 
---
 drivers/power/supply/power_supply_core.c | 41 
 include/linux/power_supply.h |  2 ++
 2 files changed, 43 insertions(+)

diff --git a/drivers/power/supply/power_supply_core.c 
b/drivers/power/supply/power_supply_core.c
index 0741fcef3b44..3f92574222de 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -375,6 +375,47 @@ int power_supply_is_system_supplied(void)
 }
 EXPORT_SYMBOL_GPL(power_supply_is_system_supplied);
 
+static int __power_supply_get_supplier_max_current(struct device *dev,
+  void *data)
+{
+   union power_supply_propval ret = {0,};
+   struct power_supply *epsy = dev_get_drvdata(dev);
+   struct power_supply *psy = data;
+
+   if (__power_supply_is_supplied_by(epsy, psy))
+   if (!epsy->desc->get_property(epsy,
+ POWER_SUPPLY_PROP_CURRENT_MAX,
+ ))
+   return ret.intval;
+
+   return 0;
+}
+
+int power_supply_set_input_current_limit_from_supplier(struct power_supply 
*psy)
+{
+   union power_supply_propval val = {0,};
+   int curr;
+
+   if (!psy->desc->set_property)
+   return -EINVAL;
+
+   /*
+* This function is not intended for use with a supply with multiple
+* suppliers, we simply pick the first supply to report a non 0
+* max-current.
+*/
+   curr = class_for_each_device(power_supply_class, NULL, psy,
+ __power_supply_get_supplier_max_current);
+   if (curr <= 0)
+   return (curr == 0) ? -ENODEV : curr;
+
+   val.intval = curr;
+
+   return psy->desc->set_property(psy,
+   POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT, );
+}
+EXPORT_SYMBOL_GPL(power_supply_set_input_current_limit_from_supplier);
+
 int power_supply_set_battery_charged(struct power_supply *psy)
 {
if (atomic_read(>use_cnt) >= 0 &&
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index de89066b72b1..79e90b3d3288 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -332,6 +332,8 @@ extern int power_supply_get_battery_info(struct 
power_supply *psy,
 struct power_supply_battery_info 
*info);
 extern void power_supply_changed(struct power_supply *psy);
 extern int power_supply_am_i_supplied(struct power_supply *psy);
+extern int power_supply_set_input_current_limit_from_supplier(
+struct power_supply *psy);
 extern int power_supply_set_battery_charged(struct power_supply *psy);
 
 #ifdef CONFIG_POWER_SUPPLY
-- 
2.13.3