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