Merge branch 'serial-from-alan'

* serial-from-alan: (79 commits)
  moxa: prevent opening unavailable ports
  imx: serial: use tty_encode_baud_rate to set true rate
  imx: serial: add IrDA support to serial driver
  imx: serial: use rational library function
  lib: isolate rational fractions helper function
  imx: serial: handle initialisation failure correctly
  imx: serial: be sure to stop xmit upon shutdown
  imx: serial: notify higher layers in case xmit IRQ was not called
  imx: serial: fix one bit field type
  imx: serial: fix whitespaces (no changes in functionality)
  tty: use prepare/finish_wait
  tty: remove sleep_on
  sierra: driver interface blacklisting
  sierra: driver urb handling improvements
  tty: resolve some sierra breakage
  timbuart: Fix the termios logic
  serial: Added Timberdale UART driver
  tty: Add URL for ttydev queue
  devpts: unregister the file system on error
  tty: Untangle termios and mm mutex dependencies
  ...