usb: typec: Standardize PD Revision format with Type-C Revision

The Type-C Revision was in a specific BCD format "0120H" for 1.2.
USB PD revision numbers follow a similar pattern with "0300H" for 3.0.

Standardizes the sysfs format for usb_power_delivery_revision
to align with the BCD format used for usb_typec_revision.

Example values:
- "2.0": USB Power Delivery Release 2.0
- "3.0": USB Power Delivery Release 3.0
- "3.1": USB Power Delivery Release 3.1
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Benson Leung <bleung@chromium.org>
Link: https://lore.kernel.org/r/20210129061406.2680146-2-bleung@chromium.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/ABI/testing/sysfs-class-typec

@@ -105,7 +105,12 @@ Date:		April 2017
 Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
 Description:
 		Revision number of the supported USB Power Delivery
-		specification, or 0 when USB Power Delivery is not supported.
+		specification, or 0.0 when USB Power Delivery is not supported.
+
+		Example values:
+		- "2.0": USB Power Delivery Release 2.0
+		- "3.0": USB Power Delivery Release 3.0
+		- "3.1": USB Power Delivery Release 3.1
 
 What:		/sys/class/typec/<port>/usb_typec_revision
 Date:		April 2017

drivers/usb/typec/class.c

@@ -1500,8 +1500,9 @@ static ssize_t usb_power_delivery_revision_show(struct device *dev,
 						char *buf)
 {
 	struct typec_port *p = to_typec_port(dev);
+	u16 rev = p->cap->pd_revision;
 
-	return sprintf(buf, "%d\n", (p->cap->pd_revision >> 8) & 0xff);
+	return sprintf(buf, "%d.%d\n", (rev >> 8) & 0xff, (rev >> 4) & 0xf);
 }
 static DEVICE_ATTR_RO(usb_power_delivery_revision);