usb: typec: Add partner PD object wrapper

Some port drivers may want to set a Type-C partner as a parent for a
USB Power Delivery object, but the Type-C partner struct isn't exposed
outside of the Type-C class driver. Add a wrapper to
usb_power_delivery_register() which sets the provided Type-C partner
as a parent to the USB PD object. This helps to avoid exposing the
Type-C partner's device struct unnecessarily.

Cc: Benson Leung <bleung@chromium.org>
Suggested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Link: https://lore.kernel.org/r/20221122220538.2991775-2-pmalani@chromium.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/class.c

@@ -821,6 +821,25 @@ void typec_partner_set_svdm_version(struct typec_partner *partner,
 }
 EXPORT_SYMBOL_GPL(typec_partner_set_svdm_version);
 
+/**
+ * typec_partner_usb_power_delivery_register - Register Type-C partner USB Power Delivery Support
+ * @partner: Type-C partner device.
+ * @desc: Description of the USB PD contract.
+ *
+ * This routine is a wrapper around usb_power_delivery_register(). It registers
+ * USB Power Delivery Capabilities for a Type-C partner device. Specifically,
+ * it sets the Type-C partner device as a parent for the resulting USB Power Delivery object.
+ *
+ * Returns handle to struct usb_power_delivery or ERR_PTR.
+ */
+struct usb_power_delivery *
+typec_partner_usb_power_delivery_register(struct typec_partner *partner,
+					  struct usb_power_delivery_desc *desc)
+{
+	return usb_power_delivery_register(&partner->dev, desc);
+}
+EXPORT_SYMBOL_GPL(typec_partner_usb_power_delivery_register);
+
 /**
  * typec_register_partner - Register a USB Type-C Partner
  * @port: The USB Type-C Port the partner is connected to

include/linux/usb/typec.h

@@ -23,6 +23,7 @@ struct fwnode_handle;
 struct device;
 
 struct usb_power_delivery;
+struct usb_power_delivery_desc;
 
 enum typec_port_type {
 	TYPEC_PORT_SRC,
@@ -327,6 +328,9 @@ void typec_partner_set_svdm_version(struct typec_partner *partner,
 				    enum usb_pd_svdm_ver svdm_version);
 int typec_get_negotiated_svdm_version(struct typec_port *port);
 
+struct usb_power_delivery *typec_partner_usb_power_delivery_register(struct typec_partner *partner,
+							struct usb_power_delivery_desc *desc);
+
 int typec_port_set_usb_power_delivery(struct typec_port *port, struct usb_power_delivery *pd);
 int typec_partner_set_usb_power_delivery(struct typec_partner *partner,
 					 struct usb_power_delivery *pd);