Add a serial driver for the SiFive UART, found on SiFive FU540 devices
(among others).
The underlying serial IP block is relatively basic, and currently does
not support serial break detection. Further information on the IP
block can be found in the documentation and Chisel sources:
https://static.dev.sifive.com/FU540-C000-v1.0.pdfhttps://github.com/sifive/sifive-blocks/tree/master/src/main/scala/devices/uart
This driver was written in collaboration with Wesley Terpstra
<wesley@sifive.com>.
Boot-tested on a SiFive HiFive Unleashed A00 board.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Wesley Terpstra <wesley@sifive.com>
Cc: linux-serial@vger.kernel.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
a496e047bd