blob: 45689d70029b624a7728367a092867a3e910103c [file] [log] [blame]
# SPDX-License-Identifier: Apache-2.0
menuconfig UART_NS16550
bool "NS16550 serial driver"
select SERIAL_HAS_DRIVER
select SERIAL_SUPPORT_INTERRUPT
help
This option enables the NS16550 serial driver.
This driver can be used for the serial hardware
available on x86 boards.
if UART_NS16550
config UART_NS16550_LINE_CTRL
bool "Serial Line Control for Apps"
depends on UART_LINE_CTRL
help
This enables the API for apps to control the serial line,
such as CTS and RTS.
Says n if not sure.
config UART_NS16550_DRV_CMD
bool "Driver Commands"
depends on UART_DRV_CMD
help
This enables the API for apps to send commands to driver.
Says n if not sure.
choice
prompt "UART variant"
default UART_NS16550_VARIANT_NS16550
help
Select UART device variant
config UART_NS16550_VARIANT_NS16550
bool "UART 16550 (16-bytes FIFO)"
help
This enables support for 16-bytes FIFO if UART controller is 16550.
config UART_NS16550_VARIANT_NS16750
bool "UART 16750 (64-bytes FIFO and auto flow control)"
help
This enables support for 64-bytes FIFO and automatic hardware
flow control if UART controller is 16750.
config UART_NS16550_VARIANT_NS16950
bool "UART 16950 (128-bytes FIFO and auto flow control)"
help
This enables support for 128-bytes FIFO and automatic hardware flow control.
endchoice
config UART_NS16550_ACCESS_WORD_ONLY
bool "NS16550 only allows word access"
help
In some case, e.g. ARC HS Development kit, the peripheral space of ns
16550 (DesignWare UART) only allows word access, byte access will raise
exception.
config UART_NS16550_ACCESS_IOPORT
bool
help
When enabled, NS16550 will not be a memory mapped device. This option
must be selected at SoC/board level if needed.
menu "NS16550 Workarounds"
config UART_NS16550_WA_ISR_REENABLE_INTERRUPT
bool "Re-enable interrupts by toggling IER at end of ISR"
depends on UART_INTERRUPT_DRIVEN
help
In some configurations (e.g. edge interrupt triggers),
an interruptible event occurs during ISR and the host interrupt
controller does not see the new event due to IIR is constantly
asserting interrupts. For example, the callback handles RX and
then TX. If another character comes in before end of TX processing
(TX interrupt still asserts while raising RX interrupt), the host
interrupt controller may not see this new event. So if needed,
the IER is being toggled to re-assert interrupts at the end of ISR
to nudge the host interrupt controller to fire the ISR again.
endmenu
endif # UART_NS16550