[PATCH 2/2] platform/chrome: cros_ec_types: Support disconnect events without partners

[Rajmohan Mani]

There are certain scenarios, where a disconnect event might
occur on a Type-C port with no port partners. This is required
to enable communication to Burnside Bridge USB4 retimers.

Signed-off-by: Rajmohan Mani <rajmohan.m...@intel.com>
---
 drivers/platform/chrome/cros_ec_typec.c | 26 ++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_typec.c 
b/drivers/platform/chrome/cros_ec_typec.c
index 3d8ff3f8a514..d89fe51b74b1 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -203,20 +203,26 @@ static void cros_typec_unregister_altmodes(struct 
cros_typec_data *typec, int po
        }
 }
 
-static void cros_typec_remove_partner(struct cros_typec_data *typec,
-                                    int port_num)
+static int cros_typec_usb_disconnect_state(struct cros_typec_port *port)
 {
-       struct cros_typec_port *port = typec->ports[port_num];
-
-       cros_typec_unregister_altmodes(typec, port_num, true);
-
        port->state.alt = NULL;
        port->state.mode = TYPEC_STATE_USB;
        port->state.data = NULL;
 
        usb_role_switch_set_role(port->role_sw, USB_ROLE_NONE);
        typec_switch_set(port->ori_sw, TYPEC_ORIENTATION_NONE);
-       typec_mux_set(port->mux, &port->state);
+
+       return typec_mux_set(port->mux, &port->state);
+}
+
+static void cros_typec_remove_partner(struct cros_typec_data *typec,
+                                     int port_num)
+{
+       struct cros_typec_port *port = typec->ports[port_num];
+
+       cros_typec_unregister_altmodes(typec, port_num, true);
+
+       cros_typec_usb_disconnect_state(port);
 
        typec_unregister_partner(port->partner);
        port->partner = NULL;
@@ -536,6 +542,11 @@ static int cros_typec_configure_mux(struct cros_typec_data 
*typec, int port_num,
        enum typec_orientation orientation;
        int ret;
 
+       if (mux_flags == USB_PD_MUX_NONE) {
+               ret = cros_typec_usb_disconnect_state(port);
+               goto mux_ack;
+       }
+
        if (mux_flags & USB_PD_MUX_POLARITY_INVERTED)
                orientation = TYPEC_ORIENTATION_REVERSE;
        else
@@ -569,6 +580,7 @@ static int cros_typec_configure_mux(struct cros_typec_data 
*typec, int port_num,
                        mux_flags);
        }
 
+mux_ack:
        if (!typec->needs_mux_ack)
                return ret;
 
-- 
2.30.0