On Mon, Nov 10, 2014 at 11:22 AM, Rob Herring <robh@xxxxxxxxxx> wrote: >>> This can be solved with a udev rule to create sym links. >> >> Is it safe to register two console drivers named "ttyS" with the same >> major/minor numbers? Maybe there is a trick to making them coexist? > > No, but I think you can do dynamic minor numbers. I seem to recall > this coming up with the Samsung UARTs a while back. The other variations I've seen in the tree are: nwpserial: ttySQ, major 4 minor 68 (not 64) sunhv, sunsab, sunsu, sunzilog: set uart_driver->major to 4 but let uart_driver->minor default to 0 SERIAL_ATMEL_TTYAT: compile-time selectable between ttySn (4/64) and ttyATn (204/154). txx9 does something similar using SERIAL_TXX9_STDSERIAL. A whole bunch of other SoC serial drivers use major 204 and a custom name like "ttyAL". Some of these show up in Documentation/devices.txt; others don't. ~3 drivers use 204/64 from the middle of the Altix assigned range. What is the current best practice for new drivers?
