# 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 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 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 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