Since Motorola has finally released the source code for the mux_cli.o and gprsv.o modules of their 2.4.17 kernel on opensource.motorola.com, I've started to clean them up and port them to 2.6.x.
Due to the questionable coding style of that original source code, and the many interface changes in the TTY layer between 2.4.x and 2.6.x, this turns out to be a bigger task than expected. With some luck, I'll find some time tomorrow at ph-neutral to finish the initial port.
Once that code works on 2.6.x, I already have a quite long list of TODO's. First of all, the lower-layer interface needs to be cleaned up. Ideally, the whole TS 07.10 implementation is a TTY line discipline that can be stacked on top of any UART, together with a virtual/fake UART that makes use of the Motorola specific TS07.10 USB transport.