K 10
svn:author
V 8
sgalabov
K 8
svn:date
V 27
2016-04-07T11:16:32.322475Z
K 7
svn:log
V 892
Initial import of Ralink/Mediatek MIPS SoC support #4

UART drivers.

- uart_dev_mtk.[ch] are the old-style Mediatek/Ralink-specific UART driver
  as also found in sys/mips/rt305x/uart_dev_rt305x.c, with minor improvements
  and FDT attachment enabled for the appropriate SoCs.
- uart_dev_mtk_ns8250.c is the new-style ns16550a-compatible UART driver
  found in newer Mediatek SoCs. It uses the uart_dev_ns8250.c driver
  indirectly and is basically just a wrapper around it and only overrides its
  probe method.
  The reason I am not using the uart_dev_ns8250.c driver directly is because
  I have some code that does UART clock detection before initializing the
  UART, so that we don't need to hard-code the UART clock frequency in the
  dts files for each board.

Approved by:	adrian (mentor)
Sponsored by:	Smartcom - Bulgaria AD
Differential Revision:	https://reviews.freebsd.org/D5840

END