drivers/char/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0
   2 #
   3 # Character device configuration
   4 #
   5
   6 menu "Character devices"
   7
   8 source "drivers/tty/Kconfig"
   9
  10 config DEVMEM
  11         bool "/dev/mem virtual device support"
  12         default y
  13         help
  14           Say Y here if you want to support the /dev/mem device.
  15           The /dev/mem device is used to access areas of physical
  16           memory.
  17           When in doubt, say "Y".
  18
  19 config DEVKMEM
  20         bool "/dev/kmem virtual device support"
  21         # On arm64, VMALLOC_START < PAGE_OFFSET, which confuses kmem read/write
  22         depends on !ARM64
  23         help
  24           Say Y here if you want to support the /dev/kmem device. The
  25           /dev/kmem device is rarely used, but can be used for certain
  26           kind of kernel debugging operations.
  27           When in doubt, say "N".
  28
  29 config SGI_SNSC
  30         bool "SGI Altix system controller communication support"
  31         depends on (IA64_SGI_SN2 || IA64_GENERIC)
  32         help
  33           If you have an SGI Altix and you want to enable system
  34           controller communication from user space (you want this!),
  35           say Y.  Otherwise, say N.
  36
  37 config SGI_TIOCX
  38        bool "SGI TIO CX driver support"
  39        depends on (IA64_SGI_SN2 || IA64_GENERIC)
  40        help
  41          If you have an SGI Altix and you have fpga devices attached
  42          to your TIO, say Y here, otherwise say N.
  43
  44 config SGI_MBCS
  45        tristate "SGI FPGA Core Services driver support"
  46        depends on SGI_TIOCX
  47        help
  48          If you have an SGI Altix with an attached SABrick
  49          say Y or M here, otherwise say N.
  50
  51 source "drivers/tty/serial/Kconfig"
  52 source "drivers/tty/serdev/Kconfig"
  53
  54 config TTY_PRINTK
  55         tristate "TTY driver to output user messages via printk"
  56         depends on EXPERT && TTY
  57         default n
  58         ---help---
  59           If you say Y here, the support for writing user messages (i.e.
  60           console messages) via printk is available.
  61
  62           The feature is useful to inline user messages with kernel
  63           messages.
  64           In order to use this feature, you should output user messages
  65           to /dev/ttyprintk or redirect console to this TTY.
  66
  67           If unsure, say N.
  68
  69 config BFIN_OTP
  70         tristate "Blackfin On-Chip OTP Memory Support"
  71         depends on BLACKFIN && (BF51x || BF52x || BF54x)
  72         default y
  73         help
  74           If you say Y here, you will get support for a character device
  75           interface into the One Time Programmable memory pages that are
  76           stored on the Blackfin processor.  This will not get you access
  77           to the secure memory pages however.  You will need to write your
  78           own secure code and reader for that.
  79
  80           To compile this driver as a module, choose M here: the module
  81           will be called bfin-otp.
  82
  83           If unsure, it is safe to say Y.
  84
  85 config BFIN_OTP_WRITE_ENABLE
  86         bool "Enable writing support of OTP pages"
  87         depends on BFIN_OTP
  88         default n
  89         help
  90           If you say Y here, you will enable support for writing of the
  91           OTP pages.  This is dangerous by nature as you can only program
  92           the pages once, so only enable this option when you actually
  93           need it so as to not inadvertently clobber data.
  94
  95           If unsure, say N.
  96
  97 config PRINTER
  98         tristate "Parallel printer support"
  99         depends on PARPORT
 100         ---help---
 101           If you intend to attach a printer to the parallel port of your Linux
 102           box (as opposed to using a serial printer; if the connector at the
 103           printer has 9 or 25 holes ["female"], then it's serial), say Y.
 104           Also read the Printing-HOWTO, available from
 105           <http://www.tldp.org/docs.html#howto>.
 106
 107           It is possible to share one parallel port among several devices
 108           (e.g. printer and ZIP drive) and it is safe to compile the
 109           corresponding drivers into the kernel.
 110
 111           To compile this driver as a module, choose M here and read
 112           <file:Documentation/parport.txt>.  The module will be called lp.
 113
 114           If you have several parallel ports, you can specify which ports to
 115           use with the "lp" kernel command line option.  (Try "man bootparam"
 116           or see the documentation of your boot loader (lilo or loadlin) about
 117           how to pass options to the kernel at boot time.)  The syntax of the
 118           "lp" command line option can be found in <file:drivers/char/lp.c>.
 119
 120           If you have more than 8 printers, you need to increase the LP_NO
 121           macro in lp.c and the PARPORT_MAX macro in parport.h.
 122
 123 config LP_CONSOLE
 124         bool "Support for console on line printer"
 125         depends on PRINTER
 126         ---help---
 127           If you want kernel messages to be printed out as they occur, you
 128           can have a console on the printer. This option adds support for
 129           doing that; to actually get it to happen you need to pass the
 130           option "console=lp0" to the kernel at boot time.
 131
 132           If the printer is out of paper (or off, or unplugged, or too
 133           busy..) the kernel will stall until the printer is ready again.
 134           By defining CONSOLE_LP_STRICT to 0 (at your own risk) you
 135           can make the kernel continue when this happens,
 136           but it'll lose the kernel messages.
 137
 138           If unsure, say N.
 139
 140 config PPDEV
 141         tristate "Support for user-space parallel port device drivers"
 142         depends on PARPORT
 143         ---help---
 144           Saying Y to this adds support for /dev/parport device nodes.  This
 145           is needed for programs that want portable access to the parallel
 146           port, for instance deviceid (which displays Plug-and-Play device
 147           IDs).
 148
 149           This is the parallel port equivalent of SCSI generic support (sg).
 150           It is safe to say N to this -- it is not needed for normal printing
 151           or parallel port CD-ROM/disk support.
 152
 153           To compile this driver as a module, choose M here: the
 154           module will be called ppdev.
 155
 156           If unsure, say N.
 157
 158 source "drivers/tty/hvc/Kconfig"
 159
 160 config VIRTIO_CONSOLE
 161         tristate "Virtio console"
 162         depends on VIRTIO && TTY
 163         select HVC_DRIVER
 164         help
 165           Virtio console for use with hypervisors.
 166
 167           Also serves as a general-purpose serial device for data
 168           transfer between the guest and host.  Character devices at
 169           /dev/vportNpn will be created when corresponding ports are
 170           found, where N is the device number and n is the port number
 171           within that device.  If specified by the host, a sysfs
 172           attribute called 'name' will be populated with a name for
 173           the port which can be used by udev scripts to create a
 174           symlink to the device.
 175
 176 config IBM_BSR
 177         tristate "IBM POWER Barrier Synchronization Register support"
 178         depends on PPC_PSERIES
 179         help
 180           This devices exposes a hardware mechanism for fast synchronization
 181           of threads across a large system which avoids bouncing a cacheline
 182           between several cores on a system
 183
 184 config POWERNV_OP_PANEL
 185         tristate "IBM POWERNV Operator Panel Display support"
 186         depends on PPC_POWERNV
 187         default m
 188         help
 189           If you say Y here, a special character device node, /dev/op_panel,
 190           will be created which exposes the operator panel display on IBM
 191           Power Systems machines with FSPs.
 192
 193           If you don't require access to the operator panel display from user
 194           space, say N.
 195
 196           If unsure, say M here to build it as a module called powernv-op-panel.
 197
 198 source "drivers/char/ipmi/Kconfig"
 199
 200 config DS1620
 201         tristate "NetWinder thermometer support"
 202         depends on ARCH_NETWINDER
 203         help
 204           Say Y here to include support for the thermal management hardware
 205           found in the NetWinder. This driver allows the user to control the
 206           temperature set points and to read the current temperature.
 207
 208           It is also possible to say M here to build it as a module (ds1620)
 209           It is recommended to be used on a NetWinder, but it is not a
 210           necessity.
 211
 212 config NWBUTTON
 213         tristate "NetWinder Button"
 214         depends on ARCH_NETWINDER
 215         ---help---
 216           If you say Y here and create a character device node /dev/nwbutton
 217           with major and minor numbers 10 and 158 ("man mknod"), then every
 218           time the orange button is pressed a number of times, the number of
 219           times the button was pressed will be written to that device.
 220
 221           This is most useful for applications, as yet unwritten, which
 222           perform actions based on how many times the button is pressed in a
 223           row.
 224
 225           Do not hold the button down for too long, as the driver does not
 226           alter the behaviour of the hardware reset circuitry attached to the
 227           button; it will still execute a hard reset if the button is held
 228           down for longer than approximately five seconds.
 229
 230           To compile this driver as a module, choose M here: the
 231           module will be called nwbutton.
 232
 233           Most people will answer Y to this question and "Reboot Using Button"
 234           below to be able to initiate a system shutdown from the button.
 235
 236 config NWBUTTON_REBOOT
 237         bool "Reboot Using Button"
 238         depends on NWBUTTON
 239         help
 240           If you say Y here, then you will be able to initiate a system
 241           shutdown and reboot by pressing the orange button a number of times.
 242           The number of presses to initiate the shutdown is two by default,
 243           but this can be altered by modifying the value of NUM_PRESSES_REBOOT
 244           in nwbutton.h and recompiling the driver or, if you compile the
 245           driver as a module, you can specify the number of presses at load
 246           time with "insmod button reboot_count=<something>".
 247
 248 config NWFLASH
 249         tristate "NetWinder flash support"
 250         depends on ARCH_NETWINDER
 251         ---help---
 252           If you say Y here and create a character device /dev/flash with
 253           major 10 and minor 160 you can manipulate the flash ROM containing
 254           the NetWinder firmware. Be careful as accidentally overwriting the
 255           flash contents can render your computer unbootable. On no account
 256           allow random users access to this device. :-)
 257
 258           To compile this driver as a module, choose M here: the
 259           module will be called nwflash.
 260
 261           If you're not sure, say N.
 262
 263 source "drivers/char/hw_random/Kconfig"
 264
 265 config NVRAM
 266         tristate "/dev/nvram support"
 267         depends on ATARI || X86 || (ARM && RTC_DRV_CMOS) || GENERIC_NVRAM
 268         ---help---
 269           If you say Y here and create a character special file /dev/nvram
 270           with major number 10 and minor number 144 using mknod ("man mknod"),
 271           you get read and write access to the extra bytes of non-volatile
 272           memory in the real time clock (RTC), which is contained in every PC
 273           and most Ataris.  The actual number of bytes varies, depending on the
 274           nvram in the system, but is usually 114 (128-14 for the RTC).
 275
 276           This memory is conventionally called "CMOS RAM" on PCs and "NVRAM"
 277           on Ataris. /dev/nvram may be used to view settings there, or to
 278           change them (with some utility). It could also be used to frequently
 279           save a few bits of very important data that may not be lost over
 280           power-off and for which writing to disk is too insecure. Note
 281           however that most NVRAM space in a PC belongs to the BIOS and you
 282           should NEVER idly tamper with it. See Ralf Brown's interrupt list
 283           for a guide to the use of CMOS bytes by your BIOS.
 284
 285           On Atari machines, /dev/nvram is always configured and does not need
 286           to be selected.
 287
 288           To compile this driver as a module, choose M here: the
 289           module will be called nvram.
 290
 291 #
 292 # These legacy RTC drivers just cause too many conflicts with the generic
 293 # RTC framework ... let's not even try to coexist any more.
 294 #
 295 if RTC_LIB=n
 296
 297 config RTC
 298         tristate "Enhanced Real Time Clock Support (legacy PC RTC driver)"
 299         depends on ALPHA || (MIPS && MACH_LOONGSON64)
 300         ---help---
 301           If you say Y here and create a character special file /dev/rtc with
 302           major number 10 and minor number 135 using mknod ("man mknod"), you
 303           will get access to the real time clock (or hardware clock) built
 304           into your computer.
 305
 306           Every PC has such a clock built in. It can be used to generate
 307           signals from as low as 1Hz up to 8192Hz, and can also be used
 308           as a 24 hour alarm. It reports status information via the file
 309           /proc/driver/rtc and its behaviour is set by various ioctls on
 310           /dev/rtc.
 311
 312           If you run Linux on a multiprocessor machine and said Y to
 313           "Symmetric Multi Processing" above, you should say Y here to read
 314           and set the RTC in an SMP compatible fashion.
 315
 316           If you think you have a use for such a device (such as periodic data
 317           sampling), then say Y here, and read <file:Documentation/rtc.txt>
 318           for details.
 319
 320           To compile this driver as a module, choose M here: the
 321           module will be called rtc.
 322
 323 config JS_RTC
 324         tristate "Enhanced Real Time Clock Support"
 325         depends on SPARC32 && PCI
 326         ---help---
 327           If you say Y here and create a character special file /dev/rtc with
 328           major number 10 and minor number 135 using mknod ("man mknod"), you
 329           will get access to the real time clock (or hardware clock) built
 330           into your computer.
 331
 332           Every PC has such a clock built in. It can be used to generate
 333           signals from as low as 1Hz up to 8192Hz, and can also be used
 334           as a 24 hour alarm. It reports status information via the file
 335           /proc/driver/rtc and its behaviour is set by various ioctls on
 336           /dev/rtc.
 337
 338           If you think you have a use for such a device (such as periodic data
 339           sampling), then say Y here, and read <file:Documentation/rtc.txt>
 340           for details.
 341
 342           To compile this driver as a module, choose M here: the
 343           module will be called js-rtc.
 344
 345 config EFI_RTC
 346         bool "EFI Real Time Clock Services"
 347         depends on IA64
 348
 349 config DS1302
 350         tristate "DS1302 RTC support"
 351         depends on M32R && (PLAT_M32700UT || PLAT_OPSPUT)
 352         help
 353           If you say Y here and create a character special file /dev/rtc with
 354           major number 121 and minor number 0 using mknod ("man mknod"), you
 355           will get access to the real time clock (or hardware clock) built
 356           into your computer.
 357
 358 endif # RTC_LIB
 359
 360 config DTLK
 361         tristate "Double Talk PC internal speech card support"
 362         depends on ISA
 363         help
 364           This driver is for the DoubleTalk PC, a speech synthesizer
 365           manufactured by RC Systems (<http://www.rcsys.com/>).  It is also
 366           called the `internal DoubleTalk'.
 367
 368           To compile this driver as a module, choose M here: the
 369           module will be called dtlk.
 370
 371 config XILINX_HWICAP
 372         tristate "Xilinx HWICAP Support"
 373         depends on XILINX_VIRTEX || MICROBLAZE
 374         help
 375           This option enables support for Xilinx Internal Configuration
 376           Access Port (ICAP) driver.  The ICAP is used on Xilinx Virtex
 377           FPGA platforms to partially reconfigure the FPGA at runtime.
 378
 379           If unsure, say N.
 380
 381 config R3964
 382         tristate "Siemens R3964 line discipline"
 383         depends on TTY && BROKEN
 384         ---help---
 385           This driver allows synchronous communication with devices using the
 386           Siemens R3964 packet protocol. Unless you are dealing with special
 387           hardware like PLCs, you are unlikely to need this.
 388
 389           To compile this driver as a module, choose M here: the
 390           module will be called n_r3964.
 391
 392           If unsure, say N.
 393
 394 config APPLICOM
 395         tristate "Applicom intelligent fieldbus card support"
 396         depends on PCI
 397         ---help---
 398           This driver provides the kernel-side support for the intelligent
 399           fieldbus cards made by Applicom International. More information
 400           about these cards can be found on the WWW at the address
 401           <http://www.applicom-int.com/>, or by email from David Woodhouse
 402           <dwmw2@infradead.org>.
 403
 404           To compile this driver as a module, choose M here: the
 405           module will be called applicom.
 406
 407           If unsure, say N.
 408
 409 config SONYPI
 410         tristate "Sony Vaio Programmable I/O Control Device support"
 411         depends on X86_32 && PCI && INPUT
 412         ---help---
 413           This driver enables access to the Sony Programmable I/O Control
 414           Device which can be found in many (all ?) Sony Vaio laptops.
 415
 416           If you have one of those laptops, read
 417           <file:Documentation/laptops/sonypi.txt>, and say Y or M here.
 418
 419           To compile this driver as a module, choose M here: the
 420           module will be called sonypi.
 421
 422 config GPIO_TB0219
 423         tristate "TANBAC TB0219 GPIO support"
 424         depends on TANBAC_TB022X
 425         select GPIO_VR41XX
 426
 427 source "drivers/char/pcmcia/Kconfig"
 428
 429 config MWAVE
 430         tristate "ACP Modem (Mwave) support"
 431         depends on X86 && TTY
 432         select SERIAL_8250
 433         ---help---
 434           The ACP modem (Mwave) for Linux is a WinModem. It is composed of a
 435           kernel driver and a user level application. Together these components
 436           support direct attachment to public switched telephone networks (PSTNs)
 437           and support selected world wide countries.
 438
 439           This version of the ACP Modem driver supports the IBM Thinkpad 600E,
 440           600, and 770 that include on board ACP modem hardware.
 441
 442           The modem also supports the standard communications port interface
 443           (ttySx) and is compatible with the Hayes AT Command Set.
 444
 445           The user level application needed to use this driver can be found at
 446           the IBM Linux Technology Center (LTC) web site:
 447           <http://www.ibm.com/linux/ltc/>.
 448
 449           If you own one of the above IBM Thinkpads which has the Mwave chipset
 450           in it, say Y.
 451
 452           To compile this driver as a module, choose M here: the
 453           module will be called mwave.
 454
 455 config SCx200_GPIO
 456         tristate "NatSemi SCx200 GPIO Support"
 457         depends on SCx200
 458         select NSC_GPIO
 459         help
 460           Give userspace access to the GPIO pins on the National
 461           Semiconductor SCx200 processors.
 462
 463           If compiled as a module, it will be called scx200_gpio.
 464
 465 config PC8736x_GPIO
 466         tristate "NatSemi PC8736x GPIO Support"
 467         depends on X86_32 && !UML
 468         default SCx200_GPIO     # mostly N
 469         select NSC_GPIO         # needed for support routines
 470         help
 471           Give userspace access to the GPIO pins on the National
 472           Semiconductor PC-8736x (x=[03456]) SuperIO chip.  The chip
 473           has multiple functional units, inc several managed by
 474           hwmon/pc87360 driver.  Tested with PC-87366
 475
 476           If compiled as a module, it will be called pc8736x_gpio.
 477
 478 config NSC_GPIO
 479         tristate "NatSemi Base GPIO Support"
 480         depends on X86_32
 481         # selected by SCx200_GPIO and PC8736x_GPIO
 482         # what about 2 selectors differing: m != y
 483         help
 484           Common support used (and needed) by scx200_gpio and
 485           pc8736x_gpio drivers.  If those drivers are built as
 486           modules, this one will be too, named nsc_gpio
 487
 488 config RAW_DRIVER
 489         tristate "RAW driver (/dev/raw/rawN)"
 490         depends on BLOCK
 491         help
 492           The raw driver permits block devices to be bound to /dev/raw/rawN.
 493           Once bound, I/O against /dev/raw/rawN uses efficient zero-copy I/O.
 494           See the raw(8) manpage for more details.
 495
 496           Applications should preferably open the device (eg /dev/hda1)
 497           with the O_DIRECT flag.
 498
 499 config MAX_RAW_DEVS
 500         int "Maximum number of RAW devices to support (1-65536)"
 501         depends on RAW_DRIVER
 502         range 1 65536
 503         default "256"
 504         help
 505           The maximum number of RAW devices that are supported.
 506           Default is 256. Increase this number in case you need lots of
 507           raw devices.
 508
 509 config HPET
 510         bool "HPET - High Precision Event Timer" if (X86 || IA64)
 511         default n
 512         depends on ACPI
 513         help
 514           If you say Y here, you will have a miscdevice named "/dev/hpet/".  Each
 515           open selects one of the timers supported by the HPET.  The timers are
 516           non-periodic and/or periodic.
 517
 518 config HPET_MMAP
 519         bool "Allow mmap of HPET"
 520         default y
 521         depends on HPET
 522         help
 523           If you say Y here, user applications will be able to mmap
 524           the HPET registers.
 525
 526 config HPET_MMAP_DEFAULT
 527         bool "Enable HPET MMAP access by default"
 528         default y
 529         depends on HPET_MMAP
 530         help
 531           In some hardware implementations, the page containing HPET
 532           registers may also contain other things that shouldn't be
 533           exposed to the user.  This option selects the default (if
 534           kernel parameter hpet_mmap is not set) user access to the
 535           registers for applications that require it.
 536
 537 config HANGCHECK_TIMER
 538         tristate "Hangcheck timer"
 539         depends on X86 || IA64 || PPC64 || S390
 540         help
 541           The hangcheck-timer module detects when the system has gone
 542           out to lunch past a certain margin.  It can reboot the system
 543           or merely print a warning.
 544
 545 config UV_MMTIMER
 546         tristate "UV_MMTIMER Memory mapped RTC for SGI UV"
 547         depends on X86_UV
 548         default m
 549         help
 550           The uv_mmtimer device allows direct userspace access to the
 551           UV system timer.
 552
 553 source "drivers/char/tpm/Kconfig"
 554
 555 config TELCLOCK
 556         tristate "Telecom clock driver for ATCA SBC"
 557         depends on X86
 558         default n
 559         help
 560           The telecom clock device is specific to the MPCBL0010 and MPCBL0050
 561           ATCA computers and allows direct userspace access to the
 562           configuration of the telecom clock configuration settings.  This
 563           device is used for hardware synchronization across the ATCA backplane
 564           fabric.  Upon loading, the driver exports a sysfs directory,
 565           /sys/devices/platform/telco_clock, with a number of files for
 566           controlling the behavior of this hardware.
 567
 568 config DEVPORT
 569         bool "/dev/port character device"
 570         depends on ISA || PCI
 571         default y
 572         help
 573           Say Y here if you want to support the /dev/port device. The /dev/port
 574           device is similar to /dev/mem, but for I/O ports.
 575
 576 source "drivers/s390/char/Kconfig"
 577
 578 config TILE_SROM
 579         tristate "Character-device access via hypervisor to the Tilera SPI ROM"
 580         depends on TILE
 581         default y
 582         ---help---
 583           This device provides character-level read-write access
 584           to the SROM, typically via the "0", "1", and "2" devices
 585           in /dev/srom/.  The Tilera hypervisor makes the flash
 586           device appear much like a simple EEPROM, and knows
 587           how to partition a single ROM for multiple purposes.
 588
 589 source "drivers/char/xillybus/Kconfig"
 590
 591 endmenu
 592