usb: typec: Add typec_partner_set_pd_revision

The partner's PD revision may be resolved later than the port partner
registration since the port partner creation may take place once
Type-C detects the port has changed state, but before PD communication is
completed.

Add a setter so that the partner's PD revision can be attached to it once
it becomes available.

If the revision is set to a valid version (not 0), the setter will also
refresh the partner's usb_pd flag and notify on "supports_usb_power_delivery"
sysfs property as well.
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Benson Leung <bleung@chromium.org>
Link: https://lore.kernel.org/r/20210129061406.2680146-4-bleung@chromium.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/class.c

@@ -748,6 +748,36 @@ int typec_partner_set_identity(struct typec_partner *partner)
 }
 EXPORT_SYMBOL_GPL(typec_partner_set_identity);
 
+/**
+ * typec_partner_set_pd_revision - Set the PD revision supported by the partner
+ * @partner: The partner to be updated.
+ * @pd_revision:  USB Power Delivery Specification Revision supported by partner
+ *
+ * This routine is used to report that the PD revision of the port partner has
+ * become available.
+ *
+ * Returns 0 on success or negative error number on failure.
+ */
+int typec_partner_set_pd_revision(struct typec_partner *partner, u16 pd_revision)
+{
+	int ret;
+
+	if (partner->pd_revision == pd_revision)
+		return 0;
+
+	partner->pd_revision = pd_revision;
+	sysfs_notify(&partner->dev.kobj, NULL, "usb_power_delivery_revision");
+	if (pd_revision != 0 && !partner->usb_pd) {
+		partner->usb_pd = 1;
+		sysfs_notify(&partner->dev.kobj, NULL,
+			     "supports_usb_power_delivery");
+	}
+	kobject_uevent(&partner->dev.kobj, KOBJ_CHANGE);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(typec_partner_set_pd_revision);
+
 /**
  * typec_partner_set_num_altmodes - Set the number of available partner altmodes
  * @partner: The partner to be updated.

include/linux/usb/typec.h

@@ -126,6 +126,7 @@ struct typec_altmode_desc {
 	enum typec_port_data	roles;
 };
 
+int typec_partner_set_pd_revision(struct typec_partner *partner, u16 pd_revision);
 int typec_partner_set_num_altmodes(struct typec_partner *partner, int num_altmodes);
 struct typec_altmode
 *typec_partner_register_altmode(struct typec_partner *partner,