mirror_ubuntu-kernels/drivers/tty/serial/8250/Kconfig

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# SPDX-License-Identifier: GPL-2.0
#
# The 8250/16550 serial drivers. You shouldn't be in this list unless
# you somehow have an implicit or explicit dependency on SERIAL_8250.
#
config SERIAL_8250
tristate "8250/16550 and compatible serial support"
depends on !S390
select SERIAL_CORE
select SERIAL_MCTRL_GPIO if GPIOLIB
help
This selects whether you want to include the driver for the standard
serial ports. The standard answer is Y. People who might say N
here are those that are setting up dedicated Ethernet WWW/FTP
servers, or users that have one of the various bus mice instead of a
serial mouse and don't intend to use their machine's standard serial
port for anything.
To compile this driver as a module, choose M here: the
module will be called 8250.
[WARNING: Do not compile this driver as a module if you are using
non-standard serial ports, since the configuration information will
be lost when the driver is unloaded. This limitation may be lifted
in the future.]
BTW1: If you have a mouseman serial mouse which is not recognized by
the X window system, try running gpm first.
BTW2: If you intend to use a software modem (also called Winmodem)
under Linux, forget it. These modems are crippled and require
proprietary drivers which are only available under Windows.
Most people will say Y or M here, so that they can use serial mice,
modems and similar devices connecting to the standard serial ports.
config SERIAL_8250_DEPRECATED_OPTIONS
bool "Support 8250_core.* kernel options (DEPRECATED)"
depends on SERIAL_8250
default y
help
In 3.7 we renamed 8250 to 8250_core by mistake, so now we have to
accept kernel parameters in both forms like 8250_core.nr_uarts=4 and
8250.nr_uarts=4. We now renamed the module back to 8250, but if
anybody noticed in 3.7 and changed their userspace we still have to
keep the 8250_core.* options around until they revert the changes
they already did.
If 8250 is built as a module, this adds 8250_core alias instead.
If you did not notice yet and/or you have userspace from pre-3.7, it
is safe (and recommended) to say N here.
config SERIAL_8250_PNP
bool "8250/16550 PNP device support" if EXPERT
depends on SERIAL_8250 && PNP
default y
help
This builds standard PNP serial support. You may be able to
disable this feature if you only need legacy serial support.
config SERIAL_8250_16550A_VARIANTS
bool "Support for variants of the 16550A serial port"
depends on SERIAL_8250
default !X86
help
The 8250 driver can probe for many variants of the venerable 16550A
serial port. Doing so takes additional time at boot.
On modern systems, especially those using serial only for a simple
console, you can say N here.
config SERIAL_8250_FINTEK
bool "Support for Fintek variants"
depends on SERIAL_8250
help
Selecting this option will add support for the RS232 and RS485
capabilities of the Fintek F81216A LPC to 4 UART as well similar
variants.
If this option is not selected the device will be configured as a
standard 16550A serial port, however the device may not function
correctly without this option enabled.
If unsure, say N.
config SERIAL_8250_CONSOLE
bool "Console on 8250/16550 and compatible serial port"
depends on SERIAL_8250=y
select SERIAL_CORE_CONSOLE
select SERIAL_EARLYCON
help
If you say Y here, it will be possible to use a serial port 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). This could be useful if some terminal or printer is connected
to that serial port.
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=ttyS1". (Try "man bootparam" or see the documentation of
your boot loader (grub or lilo or loadlin) about how to pass options
to the kernel at boot time.)
If you don't have a VGA card installed and you say Y here, the
kernel will automatically use the first serial line, /dev/ttyS0, as
system console.
You can set that using a kernel command line option such as
"console=uart8250,io,0x3f8,9600n8"
"console=uart8250,mmio,0xff5e0000,115200n8".
and it will switch to normal serial console when the corresponding
port is ready.
"earlycon=uart8250,io,0x3f8,9600n8"
"earlycon=uart8250,mmio,0xff5e0000,115200n8".
it will not only setup early console.
If unsure, say N.
config SERIAL_8250_PARISC
tristate
depends on SERIAL_8250 && PARISC
default SERIAL_8250
config SERIAL_8250_DMA
bool "DMA support for 16550 compatible UART controllers" if EXPERT
depends on SERIAL_8250 && DMADEVICES=y
default SERIAL_8250
help
This builds DMA support that can be used with 8250/16650
compatible UART controllers that support DMA signaling.
config SERIAL_8250_PCILIB
bool
config SERIAL_8250_PCI
tristate "8250/16550 PCI device support"
depends on SERIAL_8250 && PCI
select SERIAL_8250_PCILIB
default SERIAL_8250
help
This builds standard PCI serial support. You may be able to
disable this feature if you only need legacy serial support.
Saves about 9K.
Note that serial ports on NetMos 9835 Multi-I/O cards are handled
by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL.
config SERIAL_8250_EXAR
tristate "8250/16550 Exar/Commtech PCI/PCIe device support"
depends on SERIAL_8250 && PCI
default SERIAL_8250
help
This builds support for XR17C1xx, XR17V3xx and some Commtech
422x PCIe serial cards that are not covered by the more generic
SERIAL_8250_PCI option.
config SERIAL_8250_HP300
tristate
depends on SERIAL_8250 && HP300
default SERIAL_8250
config SERIAL_8250_CS
tristate "8250/16550 PCMCIA device support"
depends on PCMCIA && SERIAL_8250
help
Say Y here to enable support for 16-bit PCMCIA serial devices,
including serial port cards, modems, and the modem functions of
multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
credit-card size devices often used with laptops.)
To compile this driver as a module, choose M here: the
module will be called serial_cs.
If unsure, say N.
config SERIAL_8250_MEN_MCB
tristate "MEN MCB UART device support"
depends on MCB && SERIAL_8250
help
This enables support for FPGA based UARTs found on many MEN
boards. This driver enables support for the 16z025, 16z057
and 16z125 UARTs.
To compile this driver as a module, chose M here: the
module will be called 8250_men_mcb.
config SERIAL_8250_NR_UARTS
int "Maximum number of 8250/16550 serial ports"
depends on SERIAL_8250
default "4"
help
Set this to the number of serial ports you want the driver
to support. This includes any ports discovered via ACPI or
PCI enumeration and any ports that may be added at run-time
via hot-plug, or any ISA multi-port serial cards.
config SERIAL_8250_RUNTIME_UARTS
int "Number of 8250/16550 serial ports to register at runtime"
depends on SERIAL_8250
range 0 SERIAL_8250_NR_UARTS
default "4"
help
Set this to the maximum number of serial ports you want
the kernel to register at boot time. This can be overridden
with the module parameter "nr_uarts", or boot-time parameter
8250.nr_uarts
config SERIAL_8250_EXTENDED
bool "Extended 8250/16550 serial driver options"
depends on SERIAL_8250
help
If you wish to use any non-standard features of the standard "dumb"
driver, say Y here. This includes HUB6 support, shared serial
interrupts, special multiport support, support for more than the
four COM 1/2/3/4 boards, etc.
Note that the answer to this question won't directly affect the
kernel: saying N will just cause the configurator to skip all
the questions about serial driver options. If unsure, say N.
config SERIAL_8250_MANY_PORTS
bool "Support more than 4 legacy serial ports"
depends on SERIAL_8250_EXTENDED
help
Say Y here if you have dumb serial boards other than the four
standard COM 1/2/3/4 ports. This may happen if you have an AST
FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
from <https://www.tldp.org/docs.html#howto>), or other custom
serial port hardware which acts similar to standard serial port
hardware. If you only use the standard COM 1/2/3/4 ports, you can
say N here to save some memory. You can also say Y if you have an
"intelligent" multiport card such as Digiboards, etc.
#
# Multi-port serial cards
#
config SERIAL_8250_FOURPORT
tristate "Support Fourport cards"
depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
help
Say Y here if you have an AST FourPort serial board.
To compile this driver as a module, choose M here: the module
will be called 8250_fourport.
config SERIAL_8250_ACCENT
tristate "Support Accent cards"
depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
help
Say Y here if you have an Accent Async serial board.
To compile this driver as a module, choose M here: the module
will be called 8250_accent.
config SERIAL_8250_ASPEED_VUART
tristate "Aspeed Virtual UART"
depends on SERIAL_8250
depends on OF
depends on MFD_SYSCON
depends on ARCH_ASPEED || COMPILE_TEST
select REGMAP
help
If you want to use the virtual UART (VUART) device on Aspeed
BMC platforms, enable this option. This enables the 16550A-
compatible device on the local LPC bus, giving a UART device
with no physical RS232 connections.
config SERIAL_8250_BOCA
tristate "Support Boca cards"
depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
help
Say Y here if you have a Boca serial board. Please read the Boca
mini-HOWTO, available from <https://www.tldp.org/docs.html#howto>
To compile this driver as a module, choose M here: the module
will be called 8250_boca.
config SERIAL_8250_EXAR_ST16C554
tristate "Support Exar ST16C554/554D Quad UART"
depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
help
The Uplogix Envoy TU301 uses this Exar Quad UART. If you are
tinkering with your Envoy TU301, or have a machine with this UART,
say Y here.
To compile this driver as a module, choose M here: the module
will be called 8250_exar_st16c554.
config SERIAL_8250_HUB6
tristate "Support Hub6 cards"
depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
help
Say Y here if you have a HUB6 serial board.
To compile this driver as a module, choose M here: the module
will be called 8250_hub6.
config SERIAL_8250_PCI1XXXX
tristate "Microchip 8250 based serial port"
depends on SERIAL_8250 && PCI
select SERIAL_8250_PCILIB
help
Select this option if you have a setup with Microchip PCIe
Switch with serial port enabled and wish to enable 8250
serial driver for the serial interface. This driver support
will ensure to support baud rates upto 1.5Mpbs.
#
# Misc. options/drivers.
#
config SERIAL_8250_SHARE_IRQ
bool "Support for sharing serial interrupts"
depends on SERIAL_8250_EXTENDED
help
Some serial boards have hardware support which allows multiple dumb
serial ports on the same board to share a single IRQ. To enable
support for this in the serial driver, say Y here.
config SERIAL_8250_DETECT_IRQ
bool "Autodetect IRQ on standard ports (unsafe)"
depends on SERIAL_8250_EXTENDED
help
Say Y here if you want the kernel to try to guess which IRQ
to use for your serial port.
This is considered unsafe; it is far better to configure the IRQ in
a boot script using the setserial command.
If unsure, say N.
config SERIAL_8250_RSA
bool "Support RSA serial ports"
depends on SERIAL_8250_EXTENDED
help
Say Y here if you have a IODATA RSA-DV II/S ISA card and
would like to use its >115kbps speeds.
You will need to provide module parameter "probe_rsa", or boot-time
parameter 8250.probe_rsa with I/O addresses of this card then.
If you don't have such card, or if unsure, say N.
config SERIAL_8250_DWLIB
bool
config SERIAL_8250_ACORN
tristate "Acorn expansion card serial port support"
depends on ARCH_ACORN && SERIAL_8250
help
If you have an Atomwide Serial card or Serial Port card for an Acorn
system, say Y to this option. The driver can handle 1, 2, or 3 port
cards. If unsure, say N.
config SERIAL_8250_BCM2835AUX
tristate "BCM2835 auxiliar mini UART support"
depends on ARCH_BCM2835 || COMPILE_TEST
depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
help
Support for the BCM2835 auxiliar mini UART.
Features and limitations of the UART are
Registers are similar to 16650 registers,
set bits in the control registers that are unsupported
are ignored and read back as 0
7/8 bit operation with 1 start and 1 stop bit
8 symbols deep fifo for rx and tx
SW controlled RTS and SW readable CTS
Clock rate derived from system clock
Uses 8 times oversampling (compared to 16 times for 16650)
Missing break detection (but break generation)
Missing framing error detection
Missing parity bit
Missing receive time-out interrupt
Missing DCD, DSR, DTR and RI signals
If unsure, say N.
config SERIAL_8250_FSL
tristate "Freescale 16550 UART support" if COMPILE_TEST && !(PPC || ARM || ARM64)
depends on SERIAL_8250
default SERIAL_8250 if PPC || ARM || ARM64
help
Selecting this option enables a workaround for a break-detection
erratum for Freescale 16550 UARTs in the 8250 driver. It also
enables support for ACPI enumeration.
config SERIAL_8250_DFL
tristate "DFL bus driver for Altera 16550 UART"
depends on SERIAL_8250 && FPGA_DFL
help
This option enables support for a Device Feature List (DFL) bus
driver for the Altera 16550 UART. One or more Altera 16550 UARTs
can be instantiated in a FPGA and then be discovered during
enumeration of the DFL bus.
To compile this driver as a module, chose M here: the
module will be called 8250_dfl.
config SERIAL_8250_DW
tristate "Support for Synopsys DesignWare 8250 quirks"
depends on SERIAL_8250
select SERIAL_8250_DWLIB
help
Selecting this option will enable handling of the extra features
present in the Synopsys DesignWare APB UART.
config SERIAL_8250_EM
tristate "Support for Emma Mobile integrated serial port"
depends on SERIAL_8250 && HAVE_CLK
depends on ARCH_RENESAS || COMPILE_TEST
help
Selecting this option will add support for the integrated serial
port hardware found on the Emma Mobile line of processors.
If unsure, say N.
config SERIAL_8250_IOC3
tristate "SGI IOC3 8250 UART support"
depends on SERIAL_8250
depends on SGI_MFD_IOC3 || COMPILE_TEST
select SERIAL_8250_EXTENDED
select SERIAL_8250_SHARE_IRQ
help
Enable this if you have a SGI Origin or Octane machine. This module
provides basic serial support by directly driving the UART chip
behind the IOC3 device on those systems. Maximum baud speed is
38400bps using this driver.
config SERIAL_8250_RT288X
bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
depends on SERIAL_8250
default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
help
Selecting this option will add support for the alternate register
layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
If unsure, say N.
config SERIAL_8250_OMAP
tristate "Support for OMAP internal UART (8250 based driver)"
depends on SERIAL_8250
depends on ARCH_OMAP2PLUS || ARCH_K3 || COMPILE_TEST
help
If you have a machine based on an Texas Instruments OMAP CPU you
can enable its onboard serial ports by enabling this option.
This driver uses ttyS instead of ttyO.
config SERIAL_8250_OMAP_TTYO_FIXUP
bool "Replace ttyO with ttyS"
depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
default y
help
This option replaces the "console=ttyO" argument with the matching
ttyS argument if the user did not specified it on the command line.
This ensures that the user can see the kernel output during boot
which he wouldn't see otherwise. The getty has still to be configured
for ttyS instead of ttyO regardless of this option.
This option is intended for people who "automatically" enable this
driver without knowing that this driver requires a different console=
argument. If you read this, please keep this option disabled and
instead update your kernel command line. If you prepare a kernel for a
distribution or other kind of larger user base then you probably want
to keep this option enabled. Otherwise people might complain about a
not booting kernel because the serial console remains silent in case
they forgot to update the command line.
config SERIAL_8250_LPC18XX
tristate "NXP LPC18xx/43xx serial port support"
depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
default ARCH_LPC18XX
help
If you have a LPC18xx/43xx based board and want to use the
serial port, say Y to this option. If unsure, say Y.
config SERIAL_8250_MT6577
tristate "Mediatek serial port support"
depends on SERIAL_8250
depends on ARCH_MEDIATEK || COMPILE_TEST
help
If you have a Mediatek based board and want to use the
serial port, say Y to this option. If unsure, say N.
config SERIAL_8250_UNIPHIER
tristate "Support for UniPhier on-chip UART"
depends on SERIAL_8250
depends on ARCH_UNIPHIER || COMPILE_TEST
help
If you have a UniPhier based board and want to use the on-chip
serial ports, say Y to this option. If unsure, say N.
config SERIAL_8250_INGENIC
tristate "Support for Ingenic SoC serial ports"
depends on SERIAL_8250
depends on OF_FLATTREE
depends on MIPS || COMPILE_TEST
help
If you have a system using an Ingenic SoC and wish to make use of
its UARTs, say Y to this option. If unsure, say N.
config SERIAL_8250_LPSS
tristate "Support for serial ports on Intel LPSS platforms"
default SERIAL_8250
depends on SERIAL_8250 && PCI
depends on X86 || COMPILE_TEST
select SERIAL_8250_DWLIB
select DW_DMAC_CORE if SERIAL_8250_DMA
select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
select RATIONAL
help
Selecting this option will enable handling of the UART found on
various Intel platforms such as:
- Intel Baytrail SoC
- Intel Braswell SoC
- Intel Quark X1000 SoC
that are not covered by the more generic SERIAL_8250_PCI option.
config SERIAL_8250_MID
tristate "Support for serial ports on Intel MID platforms"
default SERIAL_8250
depends on SERIAL_8250 && PCI
depends on X86 || COMPILE_TEST
select HSU_DMA if SERIAL_8250_DMA
select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
select RATIONAL
help
Selecting this option will enable handling of the UART found on
Intel Medfield SOC and various other Intel platforms that is not
covered by the more generic SERIAL_8250_PCI option.
config SERIAL_8250_PERICOM
tristate "Support for Pericom and Acces I/O serial ports"
default SERIAL_8250
depends on SERIAL_8250 && PCI
help
Selecting this option will enable handling of the Pericom and Acces
I/O UARTs that are not covered by the more generic SERIAL_8250_PCI
option.
config SERIAL_8250_PXA
tristate "PXA serial port support"
depends on SERIAL_8250
depends on ARCH_PXA || ARCH_MMP || COMPILE_TEST
help
If you have a machine based on an Intel XScale PXA2xx CPU you can
enable its onboard serial ports by enabling this option. The option is
applicable to both devicetree and legacy boards, and early console is
part of its support.
config SERIAL_8250_TEGRA
tristate "8250 support for Tegra serial ports"
default SERIAL_8250
depends on SERIAL_8250
depends on ARCH_TEGRA || COMPILE_TEST
help
Select this option if you have machine with an NVIDIA Tegra SoC and
wish to enable 8250 serial driver for the Tegra serial interfaces.
config SERIAL_8250_BCM7271
tristate "Broadcom 8250 based serial port"
depends on SERIAL_8250 && (ARCH_BRCMSTB || COMPILE_TEST)
default ARCH_BRCMSTB
help
If you have a Broadcom STB based board and want to use the
enhanced features of the Broadcom 8250 based serial port,
including DMA support and high accuracy BAUD rates, say
Y to this option. If unsure, say N.
config SERIAL_OF_PLATFORM
tristate "Devicetree based probing for 8250 ports"
depends on SERIAL_8250 && OF
help
This option is used for all 8250 compatible serial ports that
are probed through devicetree, including Open Firmware based
PowerPC systems and embedded systems on architectures using the
flattened device tree format.