usb: typec: Add retimer handle to port altmode

Just like it does with muxes, the Type-C bus code can update the state
of connected retimers (especially when altmode-related transitions
occur). Add a retimer handle to the port altmode struct to enable this.
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20230112221609.540754-2-pmalani@chromium.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/bus.h

@@ -7,11 +7,13 @@
 
 struct bus_type;
 struct typec_mux;
+struct typec_retimer;
 
 struct altmode {
 	unsigned int			id;
 	struct typec_altmode		adev;
 	struct typec_mux		*mux;
+	struct typec_retimer		*retimer;
 
 	enum typec_port_data		roles;
 

drivers/usb/typec/class.c

@@ -583,6 +583,7 @@ void typec_unregister_altmode(struct typec_altmode *adev)
 {
 	if (IS_ERR_OR_NULL(adev))
 		return;
+	typec_retimer_put(to_altmode(adev)->retimer);
 	typec_mux_put(to_altmode(adev)->mux);
 	device_unregister(&adev->dev);
 }
@@ -2108,16 +2109,26 @@ typec_port_register_altmode(struct typec_port *port,
 {
 	struct typec_altmode *adev;
 	struct typec_mux *mux;
+	struct typec_retimer *retimer;
 
 	mux = typec_mux_get(&port->dev, desc);
 	if (IS_ERR(mux))
 		return ERR_CAST(mux);
 
+	retimer = typec_retimer_get(&port->dev);
+	if (IS_ERR(retimer)) {
+		typec_mux_put(mux);
+		return ERR_CAST(retimer);
+	}
+
 	adev = typec_register_altmode(&port->dev, desc);
-	if (IS_ERR(adev))
+	if (IS_ERR(adev)) {
+		typec_retimer_put(retimer);
 		typec_mux_put(mux);
-	else
+	} else {
 		to_altmode(adev)->mux = mux;
+		to_altmode(adev)->retimer = retimer;
+	}
 
 	return adev;
 }