From 4bc488bf8290dcf7ac221d286995563495c0ddc2 Mon Sep 17 00:00:00 2001 From: Andrei Kuchynski Date: Fri, 26 Jun 2026 14:27:00 +0000 Subject: usb: typec: Add helper to check cable altmode support Introduce typec_cable_altmode_unsupported function to evaluate whether an alternate mode is restricted based on the connected cable's properties. Implement validation logic that parses the cable's identity to catch incompatible setups early. Alternate modes are restricted over: - cables lacking an identity header - passive cables with USB 2.0 speed - active cables unless they have corresponding plugs The function returns false if the cable is not registered or the identifier is not set. Suggested-by: Heikki Krogerus Signed-off-by: Andrei Kuchynski Reviewed-by: Benson Leung Reviewed-by: Heikki Krogerus Link: https://patch.msgid.link/20260626142702.1941182-2-akuchynski@chromium.org Signed-off-by: Greg Kroah-Hartman --- include/linux/usb/typec.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/usb/typec.h b/include/linux/usb/typec.h index d61ec38216fa..10a783b738ef 100644 --- a/include/linux/usb/typec.h +++ b/include/linux/usb/typec.h @@ -337,6 +337,7 @@ void typec_unregister_cable(struct typec_cable *cable); struct typec_cable *typec_cable_get(struct typec_port *port); void typec_cable_put(struct typec_cable *cable); int typec_cable_is_active(struct typec_cable *cable); +bool typec_cable_altmode_unsupported(struct typec_altmode *alt); struct typec_plug *typec_register_plug(struct typec_cable *cable, struct typec_plug_desc *desc); -- cgit v1.2.3