usb: typec: ucsi: Add support for the partner USB Modes

UCSI does not share the contents of the Enter_USB Message
that was used, so the active mode still has to be always
determined from the enumerated USB device. However, after
UCSI v2.0 it is possible to check separately is USB4 the
active mode.

So with USB2 and USB3 the mode is always determined from the
result of the USB enumeration, and when USB4 USB Mode is
active, UCSI driver can assign the mode directly.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20241016131834.898599-5-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/ucsi/ucsi.c

@@ -1057,6 +1057,15 @@ static int ucsi_register_partner(struct ucsi_connector *con)
 
 	con->partner = partner;
 
+	if ((con->ucsi->version >= UCSI_VERSION_3_0) &&
+	    (UCSI_CONSTAT_PARTNER_FLAGS(con->status.flags) &
+	     UCSI_CONSTAT_PARTNER_FLAG_USB4_GEN4))
+		typec_partner_set_usb_mode(partner, USB_MODE_USB4);
+	else if ((con->ucsi->version >= UCSI_VERSION_2_0) &&
+		 (UCSI_CONSTAT_PARTNER_FLAGS(con->status.flags) &
+		  UCSI_CONSTAT_PARTNER_FLAG_USB4_GEN3))
+		typec_partner_set_usb_mode(partner, USB_MODE_USB4);
+
 	return 0;
 }
 

drivers/usb/typec/ucsi/ucsi.h

@@ -347,6 +347,8 @@ struct ucsi_connector_status {
 #define UCSI_CONSTAT_PARTNER_FLAGS(_f_)		(((_f_) & GENMASK(12, 5)) >> 5)
 #define   UCSI_CONSTAT_PARTNER_FLAG_USB		1
 #define   UCSI_CONSTAT_PARTNER_FLAG_ALT_MODE	2
+#define   UCSI_CONSTAT_PARTNER_FLAG_USB4_GEN3	4
+#define   UCSI_CONSTAT_PARTNER_FLAG_USB4_GEN4	8
 #define UCSI_CONSTAT_PARTNER_TYPE(_f_)		(((_f_) & GENMASK(15, 13)) >> 13)
 #define   UCSI_CONSTAT_PARTNER_TYPE_DFP		1
 #define   UCSI_CONSTAT_PARTNER_TYPE_UFP		2