*[Silabs CP210x USB to UART Bridge VCP Drivers](http://www.silabs.com/products/mcu/pages/usbtouartbridgevcpdrivers.aspx) - supported kernels 2.6.x, 3.x.x (but 3.x.x are not up-to-date - cannot be built in 3.8.0)
*[Silabs CP210x USB to UART Bridge VCP Drivers](http://www.silabs.com/products/mcu/pages/usbtouartbridgevcpdrivers.aspx) - supported kernels 2.6.x, 3.x.x, 4.x.x..
*[cp210x: Add ioctl for GPIO support](https://lkml.org/lkml/2012/5/1/2) - patch