usb: typec: tcpm: Notify the tcpc to start connection-detection for SRPs

Some tcpc device-drivers need to explicitly be told to watch for connection
events, otherwise the tcpc will not generate any TCPM_CC_EVENTs and devices
being plugged into the Type-C port will not be noticed.

For dual-role ports tcpm_start_drp_toggling() is used to tell the tcpc to
watch for connection events. Sofar we lack a similar callback to the tcpc
for single-role ports. With some tcpc-s such as the fusb302 this means
no TCPM_CC_EVENTs will be generated when the port is configured as a
single-role port.

This commit renames start_drp_toggling to start_toggling and since the
device-properties are parsed by the tcpm-core, adds a port_type parameter
to the start_toggling callback so that the tcpc_dev driver knows the
port-type and can act accordingly when it starts toggling.

The new start_toggling callback now always gets called if defined, instead
of only being called for DRP ports.

To avoid this causing undesirable functional changes all existing
start_drp_toggling implementations are not only renamed to start_toggling,
but also get a port_type check added and return -EOPNOTSUPP when port_type
is not DRP.

Fixes: ea3b4d5523bc("usb: typec: fusb302: Resolve fixed power role ...")
Cc: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h
index 0c532ca..36a15dc 100644
--- a/include/linux/usb/tcpm.h
+++ b/include/linux/usb/tcpm.h
@@ -121,10 +121,10 @@
  *		with partner.
  * @set_pd_rx:	Called to enable or disable reception of PD messages
  * @set_roles:	Called to set power and data roles
- * @start_drp_toggling:
- *		Optional; if supported by hardware, called to start DRP
- *		toggling. DRP toggling is stopped automatically if
- *		a connection is established.
+ * @start_toggling:
+ *		Optional; if supported by hardware, called to start dual-role
+ *		toggling or single-role connection detection. Toggling stops
+ *		automatically if a connection is established.
  * @try_role:	Optional; called to set a preferred role
  * @pd_transmit:Called to transmit PD message
  * @mux:	Pointer to multiplexer data
@@ -147,8 +147,9 @@
 	int (*set_pd_rx)(struct tcpc_dev *dev, bool on);
 	int (*set_roles)(struct tcpc_dev *dev, bool attached,
 			 enum typec_role role, enum typec_data_role data);
-	int (*start_drp_toggling)(struct tcpc_dev *dev,
-				  enum typec_cc_status cc);
+	int (*start_toggling)(struct tcpc_dev *dev,
+			      enum typec_port_type port_type,
+			      enum typec_cc_status cc);
 	int (*try_role)(struct tcpc_dev *dev, int role);
 	int (*pd_transmit)(struct tcpc_dev *dev, enum tcpm_transmit_type type,
 			   const struct pd_message *msg);