# SPDX-License-Identifier: GPL-2.0
#
# Character device configuration
#
menu
"Character devices"
source
"drivers/tty/Kconfig"
config TTY_PRINTK
tristate
"TTY driver to output user messages via printk"
depends on EXPERT && TTY
default n
help
If you say Y here, the support
for writing user messages (i.e.
console messages) via printk
is available.
The feature
is useful to inline user messages
with kernel
messages.
In order to use this feature, you should output user messages
to /dev/ttyprintk
or redirect console to this TTY,
or boot
the kernel
with console=ttyprintk.
If unsure, say N.
config TTY_PRINTK_LEVEL
depends on TTY_PRINTK
int
"ttyprintk log level (1-7)"
range
1 7
default
"6"
help
Printk log level to use
for ttyprintk messages.
config PRINTER
tristate
"Parallel printer support"
depends on PARPORT
depends on HAS_IOPORT || PARPORT_NOT_PC
help
If you intend to attach a printer to the parallel port of your Linux
box (
as opposed to using a serial printer;
if the connector at the
printer has
9 or 25 holes [
"female"], then it
's serial), say Y.
Also read the Printing-HOWTO, available
from
<
https://www.tldp.org/docs.html#howto>.
It
is possible to share one parallel port among several devices
(e.g. printer
and ZIP drive)
and it
is safe to compile the
corresponding drivers into the kernel.
To compile this driver
as a module, choose M here
and read
<file:Documentation/admin-guide/parport.rst>. The module will be called lp.
If you have several parallel ports, you can specify which ports to
use
with the
"lp" kernel command line option. (
Try "man bootparam"
or see the documentation of your boot loader (lilo
or loadlin) about
how to
pass options to the kernel at boot time.) The syntax of the
"lp" command line option can be found
in <file:drivers/char/lp.c>.
If you have more than
8 printers, you need to increase the LP_NO
macro
in lp.c
and the PARPORT_MAX macro
in parport.h.
config LP_CONSOLE
bool
"Support for console on line printer"
depends on PRINTER
help
If you want kernel messages to be printed out
as they occur, you
can have a console on the printer. This option adds support
for
doing that; to actually get it to happen you need to
pass the
option
"console=lp0" to the kernel at boot time.
If the printer
is out of paper (
or off,
or unplugged,
or too
busy..) the kernel will stall until the printer
is ready again.
By defining CONSOLE_LP_STRICT to
0 (at your own risk) you
can make the kernel
continue when this happens,
but it
'll lose the kernel messages.
If unsure, say N.
config PPDEV
tristate
"Support for user-space parallel port device drivers"
depends on PARPORT
help
Saying Y to this adds support
for /dev/parport device nodes. This
is needed
for programs that want portable access to the parallel
port,
for instance deviceid (which displays Plug-
and-Play device
IDs).
This
is the parallel port equivalent of SCSI generic support (sg).
It
is safe to say N to this -- it
is not needed
for normal printing
or parallel port CD-ROM/disk support.
To compile this driver
as a module, choose M here: the
module will be called ppdev.
If unsure, say N.
config VIRTIO_CONSOLE
tristate
"Virtio console"
depends on TTY
select HVC_DRIVER
select VIRTIO
help
Virtio console
for use
with hypervisors.
Also serves
as a general-purpose serial device
for data
transfer between the guest
and host. Character devices at
/dev/vportNpn will be created when corresponding ports are
found, where N
is the device number
and n
is the port number
within that device.
If specified by the host, a sysfs
attribute called
'name' will be populated
with a name
for
the port which can be used by udev scripts to create a
symlink to the device.
config IBM_BSR
tristate
"IBM POWER Barrier Synchronization Register support"
depends on PPC_PSERIES
help
This devices exposes a hardware mechanism
for fast synchronization
of threads across a large system which avoids bouncing a cacheline
between several cores on a system
config POWERNV_OP_PANEL
tristate
"IBM POWERNV Operator Panel Display support"
depends on PPC_POWERNV
default m
help
If you say Y here, a special character device node, /dev/op_panel,
will be created which exposes the operator panel display on IBM
Power Systems machines
with FSPs.
If you don
't require access to the operator panel display from user
space, say N.
If unsure, say M here to build it
as a module called powernv-op-panel.
source
"drivers/char/ipmi/Kconfig"
config DS1620
tristate
"NetWinder thermometer support"
depends on ARCH_NETWINDER
help
Say Y here to include support
for the thermal management hardware
found
in the NetWinder. This driver allows the user to control the
temperature set points
and to read the current temperature.
It
is also possible to say M here to build it
as a module (ds1620)
It
is recommended to be used on a NetWinder, but it
is not a
necessity.
config NWBUTTON
tristate
"NetWinder Button"
depends on ARCH_NETWINDER
help
If you say Y here
and create a character device node /dev/nwbutton
with major
and minor numbers
10 and 158 (
"man mknod"), then every
time the orange button
is pressed a number of times, the number of
times the button was pressed will be written to that device.
This
is most useful
for applications,
as yet unwritten, which
perform actions based on how many times the button
is pressed
in a
row.
Do
not hold the button down
for too long,
as the driver does
not
alter the behaviour of the hardware reset circuitry attached to the
button; it will still execute a hard reset
if the button
is held
down
for longer than approximately five seconds.
To compile this driver
as a module, choose M here: the
module will be called nwbutton.
Most people will answer Y to this question
and "Reboot Using Button"
below to be able to initiate a system shutdown
from the button.
config NWBUTTON_REBOOT
bool
"Reboot Using Button"
depends on NWBUTTON
help
If you say Y here, then you will be able to initiate a system
shutdown
and reboot by pressing the orange button a number of times.
The number of presses to initiate the shutdown
is two by default,
but this can be altered by modifying the value of NUM_PRESSES_REBOOT
in nwbutton.h
and recompiling the driver
or,
if you compile the
driver
as a module, you can specify the number of presses at load
time
with "insmod button reboot_count=<something>".
config NWFLASH
tristate
"NetWinder flash support"
depends on ARCH_NETWINDER
help
If you say Y here
and create a character device /dev/flash
with
major
10 and minor
160 you can manipulate the flash ROM containing
the NetWinder firmware. Be careful
as accidentally overwriting the
flash contents can render your computer unbootable. On no account
allow random users access to this device. :-)
To compile this driver
as a module, choose M here: the
module will be called nwflash.
If you
're not sure, say N.
source
"drivers/char/hw_random/Kconfig"
config DTLK
tristate
"Double Talk PC internal speech card support"
depends on ISA
help
This driver
is for the DoubleTalk PC, a speech synthesizer
manufactured by RC Systems (<
https://www.rcsys.com/>). It
is also
called the `internal DoubleTalk
'.
To compile this driver
as a module, choose M here: the
module will be called dtlk.
config XILINX_HWICAP
tristate
"Xilinx HWICAP Support"
depends on MICROBLAZE
help
This option enables support
for Xilinx Internal Configuration
Access Port (ICAP) driver. The ICAP
is used on Xilinx Virtex
FPGA platforms to partially reconfigure the FPGA at runtime.
If unsure, say N.
config APPLICOM
tristate
"Applicom intelligent fieldbus card support"
depends on PCI
help
This driver provides the kernel-side support
for the intelligent
fieldbus cards made by Applicom International. More information
about these cards can be found on the WWW at the address
<
https://www.applicom-int.com/>,
or by email
from David Woodhouse
<dwmw2@infradead.org>.
To compile this driver
as a module, choose M here: the
module will be called applicom.
If unsure, say N.
config SONYPI
tristate
"Sony Vaio Programmable I/O Control Device support"
depends on X86_32 && PCI && INPUT && HAS_IOPORT
depends on ACPI_EC || !ACPI
help
This driver enables access to the Sony Programmable I/O Control
Device which can be found
in many (all ?) Sony Vaio laptops.
If you have one of those laptops, read
<file:Documentation/admin-guide/laptops/sonypi.rst>,
and say Y
or M here.
To compile this driver
as a module, choose M here: the
module will be called sonypi.
config MWAVE
tristate
"ACP Modem (Mwave) support"
depends on X86 && TTY
select SERIAL_8250
help
The ACP modem (Mwave)
for Linux
is a WinModem. It
is composed of a
kernel driver
and a user level application. Together these components
support direct attachment to public switched telephone networks (PSTNs)
and support selected world wide countries.
This version of the ACP Modem driver supports the IBM Thinkpad
600E,
600,
and 770 that include on board ACP modem hardware.
The modem also supports the standard communications port interface
(ttySx)
and is compatible
with the Hayes AT Command Set.
The user level application needed to use this driver can be found at
the IBM Linux Technology Center (LTC) web site:
<
http://www.ibm.com/linux/ltc/>.
If you own one of the above IBM Thinkpads which has the Mwave chipset
in it, say Y.
To compile this driver
as a module, choose M here: the
module will be called mwave.
config SCx200_GPIO
tristate
"NatSemi SCx200 GPIO Support"
depends on SCx200
select NSC_GPIO
help
Give userspace access to the GPIO pins on the National
Semiconductor SCx200 processors.
If compiled
as a module, it will be called scx200_gpio.
config PC8736x_GPIO
tristate
"NatSemi PC8736x GPIO Support"
depends on X86_32 && !UML
default SCx200_GPIO
# mostly N
select NSC_GPIO
# needed for support routines
help
Give userspace access to the GPIO pins on the National
Semiconductor PC-
8736x (x=[
03456]) SuperIO chip. The chip
has multiple functional units, inc several managed by
hwmon/pc87360 driver. Tested
with PC-
87366
If compiled
as a module, it will be called pc8736x_gpio.
config NSC_GPIO
tristate
"NatSemi Base GPIO Support"
depends on X86_32
# selected by SCx200_GPIO and PC8736x_GPIO
# what about 2 selectors differing: m != y
help
Common support used (
and needed) by scx200_gpio
and
pc8736x_gpio drivers.
If those drivers are built
as
modules, this one will be too, named nsc_gpio
config DEVMEM
bool
"/dev/mem virtual device support"
default y
help
Say Y here
if you want to support the /dev/mem device.
The /dev/mem device
is used to access areas of physical
memory.
When
in doubt, say
"Y".
config NVRAM
tristate
"/dev/nvram support"
depends on X86 || HAVE_ARCH_NVRAM_OPS
default M68K || PPC
help
If you say Y here
and create a character special file /dev/nvram
with major number
10 and minor number
144 using mknod (
"man mknod"),
you get read
and write access to the non-volatile memory.
/dev/nvram may be used to view settings
in NVRAM
or to change them
(
with some utility). It could also be used to frequently
save a few bits of very important data that may
not be lost over
power-off
and for which writing to disk
is too insecure. Note
however that most NVRAM space
in a PC belongs to the BIOS
and you
should NEVER idly tamper
with it. See Ralf Brown
's interrupt list
for a guide to the use of CMOS bytes by your BIOS.
This memory
is conventionally called
"NVRAM" on PowerPC machines,
"CMOS RAM" on PCs,
"NVRAM" on Ataris
and "PRAM" on Macintoshes.
To compile this driver
as a module, choose M here: the
module will be called nvram.
config DEVPORT
bool
"/dev/port character device"
depends on HAS_IOPORT
default y
help
Say Y here
if you want to support the /dev/port device. The /dev/port
device
is similar to /dev/mem, but
for I/O ports.
config HPET
bool
"HPET - High Precision Event Timer" if X86
default n
depends on ACPI
help
If you say Y here, you will have a miscdevice named
"/dev/hpet/". Each
open selects one of the timers supported by the HPET. The timers are
non-periodic
and/
or periodic.
config HPET_MMAP
bool
"Allow mmap of HPET"
default y
depends on HPET
help
If you say Y here, user applications will be able to mmap
the HPET registers.
config HPET_MMAP_DEFAULT
bool
"Enable HPET MMAP access by default"
default y
depends on HPET_MMAP
help
In some hardware implementations, the page containing HPET
registers may also contain other things that shouldn
't be
exposed to the user. This option selects the default (
if
kernel parameter hpet_mmap
is not set) user access to the
registers
for applications that require it.
config HANGCHECK_TIMER
tristate
"Hangcheck timer"
depends on X86 || PPC64 || S390
help
The hangcheck-timer module detects when the system has gone
out to lunch past a certain margin. It can reboot the system
or merely print a warning.
config UV_MMTIMER
tristate
"UV_MMTIMER Memory mapped RTC for SGI UV"
depends on X86_UV
default m
help
The uv_mmtimer device allows direct userspace access to the
UV system timer.
source
"drivers/char/tpm/Kconfig"
config TELCLOCK
tristate
"Telecom clock driver for ATCA SBC"
depends on X86
default n
help
The telecom clock device
is specific to the MPCBL0010
and MPCBL0050
ATCA computers
and allows direct userspace access to the
configuration of the telecom clock configuration settings. This
device
is used
for hardware synchronization across the ATCA backplane
fabric. Upon loading, the driver exports a sysfs directory,
/sys/devices/faux/telco_clock,
with a number of files
for
controlling the behavior of this hardware.
source
"drivers/s390/char/Kconfig"
source
"drivers/char/xillybus/Kconfig"
config ADI
tristate
"SPARC Privileged ADI driver"
depends on SPARC64
default m
help
SPARC M7
and newer processors utilize ADI (Application Data
Integrity) to version
and protect memory. This driver provides
read/write access to the ADI versions
for privileged processes.
This feature
is also known
as MCD (Memory Corruption Detection)
and SSM (Silicon Secured Memory). Intended consumers of this
driver include crash
and makedumpfile.
endmenu