tty: serial: add driver for the SiFive UART

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.pdf

    https://github.com/sifive/sifive-blocks/tree/master/src/main/scala/devices/uart

This driver was written in collaboration with Wesley Terpstra
<wesley@sifive.com>.

Tested on a SiFive HiFive Unleashed A00 board, using BBL and the open-
source FSBL (using a DT file based on what's targeted for mainline).

This revision incorporates changes based on comments by Julia Lawall
<julia.lawall@lip6.fr>, Emil Renner Berthing <kernel@esmil.dk>, and
Andreas Schwab <schwab@suse.de>.  Thanks also to Andreas for testing
the driver with his userspace and reporting a bug with the
set_termios implementation.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
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>
Cc: Emil Renner Berthing <kernel@esmil.dk>
Cc: Andreas Schwab <schwab@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Paul Walmsley 2019-04-12 19:01:13 -07:00 committed by Greg Kroah-Hartman
parent e5c8fe558c
commit 45c054d081
4 changed files with 1084 additions and 0 deletions

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@ -1094,6 +1094,30 @@ config SERIAL_OMAP_CONSOLE
your boot loader about how to pass options to the kernel at
boot time.)
config SERIAL_SIFIVE
tristate "SiFive UART support"
depends on OF
select SERIAL_CORE
help
Select this option if you are building a kernel for a device that
contains a SiFive UART IP block. This type of UART is present on
SiFive FU540 SoCs, among others.
config SERIAL_SIFIVE_CONSOLE
bool "Console on SiFive UART"
depends on SERIAL_SIFIVE=y
select SERIAL_CORE_CONSOLE
help
Select this option if you would like to use a SiFive UART as the
system console.
Even if you say Y here, the currently visible virtual console
(/dev/tty0) will still be used as the system console by default, but
you can alter that using a kernel command line option such as
"console=ttySIFx". (Try "man bootparam" or see the documentation of
your boot loader about how to pass options to the kernel at
boot time.)
config SERIAL_LANTIQ
bool "Lantiq serial driver"
depends on LANTIQ

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@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_MPS2_UART) += mps2-uart.o
obj-$(CONFIG_SERIAL_OWL) += owl-uart.o
obj-$(CONFIG_SERIAL_RDA) += rda-uart.o
obj-$(CONFIG_SERIAL_MILBEAUT_USIO) += milbeaut_usio.o
obj-$(CONFIG_SERIAL_SIFIVE) += sifive.o
# GPIOLIB helpers for modem control lines
obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o

1056
drivers/tty/serial/sifive.c Normal file

File diff suppressed because it is too large Load Diff

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@ -290,4 +290,7 @@
/* Socionext Milbeaut UART */
#define PORT_MLB_USIO 119
/* SiFive UART */
#define PORT_SIFIVE_V0 120
#endif /* _UAPILINUX_SERIAL_CORE_H */