SR_PRIV int usb_source_add(struct sr_session *session, struct sr_context *ctx,
int timeout, sr_receive_data_callback cb, void *cb_data);
SR_PRIV int usb_source_remove(struct sr_session *session, struct sr_context *ctx);
SR_PRIV int usb_source_add(struct sr_session *session, struct sr_context *ctx,
int timeout, sr_receive_data_callback cb, void *cb_data);
SR_PRIV int usb_source_remove(struct sr_session *session, struct sr_context *ctx);