serial: mvebu-uart: initial support for Armada-3700 serial port

Armada-3700's uart is a simple serial port, which doesn't
support. Configuring the modem control lines. The uart port has a 32
bytes Tx FIFO and a 64 bytes Rx FIFO

The uart driver implements the uart core operations. It also support the
system (early) console based on Armada-3700's serial port.

Known Issue:

The uart driver currently doesn't support clock programming, which means
the baud-rate stays with the default value configured by the bootloader
at boot time

[gregory.clement@free-electrons.com: Rewrite many part which are too long
to enumerate]

Signed-off-by: Wilson Ding <dingwei@marvell.com>
Signed-off-by: Nadav Haklai <nadavh@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index de2481cf6e58..13d4ed6caac4 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1602,6 +1602,28 @@ config SERIAL_STM32_CONSOLE
         depends on SERIAL_STM32=y
         select SERIAL_CORE_CONSOLE
 
+config SERIAL_MVEBU_UART
+        bool "Marvell EBU serial port support"
+        select SERIAL_CORE
+        help
+          This driver is for Marvell EBU SoC's UART. If you have a machine
+          based on the Armada-3700 SoC and wish to use the on-board serial
+          port,
+          say 'Y' here.
+          Otherwise, say 'N'.
+
+config SERIAL_MVEBU_CONSOLE
+        bool "Console on Marvell EBU serial port"
+        depends on SERIAL_MVEBU_UART
+        select SERIAL_CORE_CONSOLE
+        select SERIAL_EARLYCON
+        default y
+        help
+          Say 'Y' here if you wish to use Armada-3700 UART as the system console.
+          (the system console is the device which receives all kernel messages
+          and warnings and which allows logins in single user mode)
+          Otherwise, say 'N'.
+
 endmenu
 
 config SERIAL_MCTRL_GPIO