serial: nulldev: Add nulldev serial driver
Some device the serial console's initialization cannot run early during
the boot process. Hence, nulldev serial device is helpful on that
situation.
For example, if the serial module was implemented in FPGA. Serial
initialization is prohibited to run until the FPGA was programmed.
This commit is to adding nulldev serial driver. This will allows the
default console to be specified as a nulldev.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Keng Soon Cheah <keng.soon.cheah@ni.com>
Cc: Chen Yee Chew <chen.yee.chew@ni.com>
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index aeed538..13b2550 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -414,6 +414,13 @@
If you have a machine based on a Motorola IMX CPU you
can enable its onboard serial port by enabling this option.
+config NULLDEV_SERIAL
+ bool "Null serial device"
+ help
+ Select this to enable null serial device support. A null serial
+ device merely acts as a placeholder for a serial device and does
+ nothing for all it's operation.
+
config PIC32_SERIAL
bool "Support for Microchip PIC32 on-chip UART"
depends on DM_SERIAL && MACH_PIC32