10BASE-T1S is a Single Pair Ethernet (SPE) standard, intended for automotive and industrial applications. It supports a multidrop "mixing segment" of at least 25m with up to 8 nodes. This driver currently does not support per-silicon-revision config or PHY-Level Collision Avoidance (PLCA), but is suitable for establishing basic connectivity. Device details are available in the "Microchip LAN8670/1/2 10BASE-T1S Ethernet PHY Transceiver Datasheet".
(Also adds USB ID to smsc(4) for Microchip EVB-LAN8670-USB 10BASE-T1S USB adapter)