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 TTY_PRINTK 11 tristate "TTY driver to output user messages via printk" 12 depends on EXPERT && TTY 13 default n 14 help 15 If you say Y here, the support for writing user messages (i.e. 16 console messages) via printk is available. 17 18 The feature is useful to inline user messages with kernel 19 messages. 20 In order to use this feature, you should output user messages 21 to /dev/ttyprintk or redirect console to this TTY, or boot 22 the kernel with console=ttyprintk. 23 24 If unsure, say N. 25 26 config TTY_PRINTK_LEVEL 27 depends on TTY_PRINTK 28 int "ttyprintk log level (1-7)" 29 range 1 7 30 default "6" 31 help 32 Printk log level to use for ttyprintk messages. 33 34 config PRINTER 35 tristate "Parallel printer support" 36 depends on PARPORT 37 depends on HAS_IOPORT || PARPORT_NOT_PC 38 help 39 If you intend to attach a printer to the parallel port of your Linux 40 box (as opposed to using a serial printer; if the connector at the 41 printer has 9 or 25 holes ["female"], then it's serial), say Y. 42 Also read the Printing-HOWTO, available from 43 <https://www.tldp.org/docs.html#howto>. 44 45 It is possible to share one parallel port among several devices 46 (e.g. printer and ZIP drive) and it is safe to compile the 47 corresponding drivers into the kernel. 48 49 To compile this driver as a module, choose M here and read 50 <file:Documentation/admin-guide/parport.rst>. The module will be called lp. 51 52 If you have several parallel ports, you can specify which ports to 53 use with the "lp" kernel command line option. (Try "man bootparam" 54 or see the documentation of your boot loader (lilo or loadlin) about 55 how to pass options to the kernel at boot time.) The syntax of the 56 "lp" command line option can be found in <file:drivers/char/lp.c>. 57 58 If you have more than 8 printers, you need to increase the LP_NO 59 macro in lp.c and the PARPORT_MAX macro in parport.h. 60 61 config LP_CONSOLE 62 bool "Support for console on line printer" 63 depends on PRINTER 64 help 65 If you want kernel messages to be printed out as they occur, you 66 can have a console on the printer. This option adds support for 67 doing that; to actually get it to happen you need to pass the 68 option "console=lp0" to the kernel at boot time. 69 70 If the printer is out of paper (or off, or unplugged, or too 71 busy..) the kernel will stall until the printer is ready again. 72 By defining CONSOLE_LP_STRICT to 0 (at your own risk) you 73 can make the kernel continue when this happens, 74 but it'll lose the kernel messages. 75 76 If unsure, say N. 77 78 config PPDEV 79 tristate "Support for user-space parallel port device drivers" 80 depends on PARPORT 81 help 82 Saying Y to this adds support for /dev/parport device nodes. This 83 is needed for programs that want portable access to the parallel 84 port, for instance deviceid (which displays Plug-and-Play device 85 IDs). 86 87 This is the parallel port equivalent of SCSI generic support (sg). 88 It is safe to say N to this -- it is not needed for normal printing 89 or parallel port CD-ROM/disk support. 90 91 To compile this driver as a module, choose M here: the 92 module will be called ppdev. 93 94 If unsure, say N. 95 96 config VIRTIO_CONSOLE 97 tristate "Virtio console" 98 depends on TTY 99 select HVC_DRIVER 100 select VIRTIO 101 help 102 Virtio console for use with hypervisors. 103 104 Also serves as a general-purpose serial device for data 105 transfer between the guest and host. Character devices at 106 /dev/vportNpn will be created when corresponding ports are 107 found, where N is the device number and n is the port number 108 within that device. If specified by the host, a sysfs 109 attribute called 'name' will be populated with a name for 110 the port which can be used by udev scripts to create a 111 symlink to the device. 112 113 config IBM_BSR 114 tristate "IBM POWER Barrier Synchronization Register support" 115 depends on PPC_PSERIES 116 help 117 This devices exposes a hardware mechanism for fast synchronization 118 of threads across a large system which avoids bouncing a cacheline 119 between several cores on a system 120 121 config POWERNV_OP_PANEL 122 tristate "IBM POWERNV Operator Panel Display support" 123 depends on PPC_POWERNV 124 default m 125 help 126 If you say Y here, a special character device node, /dev/op_panel, 127 will be created which exposes the operator panel display on IBM 128 Power Systems machines with FSPs. 129 130 If you don't require access to the operator panel display from user 131 space, say N. 132 133 If unsure, say M here to build it as a module called powernv-op-panel. 134 135 source "drivers/char/ipmi/Kconfig" 136 137 config DS1620 138 tristate "NetWinder thermometer support" 139 depends on ARCH_NETWINDER 140 help 141 Say Y here to include support for the thermal management hardware 142 found in the NetWinder. This driver allows the user to control the 143 temperature set points and to read the current temperature. 144 145 It is also possible to say M here to build it as a module (ds1620) 146 It is recommended to be used on a NetWinder, but it is not a 147 necessity. 148 149 config NWBUTTON 150 tristate "NetWinder Button" 151 depends on ARCH_NETWINDER 152 help 153 If you say Y here and create a character device node /dev/nwbutton 154 with major and minor numbers 10 and 158 ("man mknod"), then every 155 time the orange button is pressed a number of times, the number of 156 times the button was pressed will be written to that device. 157 158 This is most useful for applications, as yet unwritten, which 159 perform actions based on how many times the button is pressed in a 160 row. 161 162 Do not hold the button down for too long, as the driver does not 163 alter the behaviour of the hardware reset circuitry attached to the 164 button; it will still execute a hard reset if the button is held 165 down for longer than approximately five seconds. 166 167 To compile this driver as a module, choose M here: the 168 module will be called nwbutton. 169 170 Most people will answer Y to this question and "Reboot Using Button" 171 below to be able to initiate a system shutdown from the button. 172 173 config NWBUTTON_REBOOT 174 bool "Reboot Using Button" 175 depends on NWBUTTON 176 help 177 If you say Y here, then you will be able to initiate a system 178 shutdown and reboot by pressing the orange button a number of times. 179 The number of presses to initiate the shutdown is two by default, 180 but this can be altered by modifying the value of NUM_PRESSES_REBOOT 181 in nwbutton.h and recompiling the driver or, if you compile the 182 driver as a module, you can specify the number of presses at load 183 time with "insmod button reboot_count=<something>". 184 185 config NWFLASH 186 tristate "NetWinder flash support" 187 depends on ARCH_NETWINDER 188 help 189 If you say Y here and create a character device /dev/flash with 190 major 10 and minor 160 you can manipulate the flash ROM containing 191 the NetWinder firmware. Be careful as accidentally overwriting the 192 flash contents can render your computer unbootable. On no account 193 allow random users access to this device. :-) 194 195 To compile this driver as a module, choose M here: the 196 module will be called nwflash. 197 198 If you're not sure, say N. 199 200 source "drivers/char/hw_random/Kconfig" 201 202 config DTLK 203 tristate "Double Talk PC internal speech card support" 204 depends on ISA 205 help 206 This driver is for the DoubleTalk PC, a speech synthesizer 207 manufactured by RC Systems (<https://www.rcsys.com/>). It is also 208 called the `internal DoubleTalk'. 209 210 To compile this driver as a module, choose M here: the 211 module will be called dtlk. 212 213 config XILINX_HWICAP 214 tristate "Xilinx HWICAP Support" 215 depends on MICROBLAZE 216 help 217 This option enables support for Xilinx Internal Configuration 218 Access Port (ICAP) driver. The ICAP is used on Xilinx Virtex 219 FPGA platforms to partially reconfigure the FPGA at runtime. 220 221 If unsure, say N. 222 223 config APPLICOM 224 tristate "Applicom intelligent fieldbus card support" 225 depends on PCI 226 help 227 This driver provides the kernel-side support for the intelligent 228 fieldbus cards made by Applicom International. More information 229 about these cards can be found on the WWW at the address 230 <https://www.applicom-int.com/>, or by email from David Woodhouse 231 <dwmw2@infradead.org>. 232 233 To compile this driver as a module, choose M here: the 234 module will be called applicom. 235 236 If unsure, say N. 237 238 config SONYPI 239 tristate "Sony Vaio Programmable I/O Control Device support" 240 depends on X86_32 && PCI && INPUT 241 help 242 This driver enables access to the Sony Programmable I/O Control 243 Device which can be found in many (all ?) Sony Vaio laptops. 244 245 If you have one of those laptops, read 246 <file:Documentation/admin-guide/laptops/sonypi.rst>, and say Y or M here. 247 248 To compile this driver as a module, choose M here: the 249 module will be called sonypi. 250 251 config MWAVE 252 tristate "ACP Modem (Mwave) support" 253 depends on X86 && TTY 254 select SERIAL_8250 255 help 256 The ACP modem (Mwave) for Linux is a WinModem. It is composed of a 257 kernel driver and a user level application. Together these components 258 support direct attachment to public switched telephone networks (PSTNs) 259 and support selected world wide countries. 260 261 This version of the ACP Modem driver supports the IBM Thinkpad 600E, 262 600, and 770 that include on board ACP modem hardware. 263 264 The modem also supports the standard communications port interface 265 (ttySx) and is compatible with the Hayes AT Command Set. 266 267 The user level application needed to use this driver can be found at 268 the IBM Linux Technology Center (LTC) web site: 269 <http://www.ibm.com/linux/ltc/>. 270 271 If you own one of the above IBM Thinkpads which has the Mwave chipset 272 in it, say Y. 273 274 To compile this driver as a module, choose M here: the 275 module will be called mwave. 276 277 config SCx200_GPIO 278 tristate "NatSemi SCx200 GPIO Support" 279 depends on SCx200 280 select NSC_GPIO 281 help 282 Give userspace access to the GPIO pins on the National 283 Semiconductor SCx200 processors. 284 285 If compiled as a module, it will be called scx200_gpio. 286 287 config PC8736x_GPIO 288 tristate "NatSemi PC8736x GPIO Support" 289 depends on X86_32 && !UML 290 default SCx200_GPIO # mostly N 291 select NSC_GPIO # needed for support routines 292 help 293 Give userspace access to the GPIO pins on the National 294 Semiconductor PC-8736x (x=[03456]) SuperIO chip. The chip 295 has multiple functional units, inc several managed by 296 hwmon/pc87360 driver. Tested with PC-87366 297 298 If compiled as a module, it will be called pc8736x_gpio. 299 300 config NSC_GPIO 301 tristate "NatSemi Base GPIO Support" 302 depends on X86_32 303 # selected by SCx200_GPIO and PC8736x_GPIO 304 # what about 2 selectors differing: m != y 305 help 306 Common support used (and needed) by scx200_gpio and 307 pc8736x_gpio drivers. If those drivers are built as 308 modules, this one will be too, named nsc_gpio 309 310 config DEVMEM 311 bool "/dev/mem virtual device support" 312 default y 313 help 314 Say Y here if you want to support the /dev/mem device. 315 The /dev/mem device is used to access areas of physical 316 memory. 317 When in doubt, say "Y". 318 319 config NVRAM 320 tristate "/dev/nvram support" 321 depends on X86 || HAVE_ARCH_NVRAM_OPS 322 default M68K || PPC 323 help 324 If you say Y here and create a character special file /dev/nvram 325 with major number 10 and minor number 144 using mknod ("man mknod"), 326 you get read and write access to the non-volatile memory. 327 328 /dev/nvram may be used to view settings in NVRAM or to change them 329 (with some utility). It could also be used to frequently 330 save a few bits of very important data that may not be lost over 331 power-off and for which writing to disk is too insecure. Note 332 however that most NVRAM space in a PC belongs to the BIOS and you 333 should NEVER idly tamper with it. See Ralf Brown's interrupt list 334 for a guide to the use of CMOS bytes by your BIOS. 335 336 This memory is conventionally called "NVRAM" on PowerPC machines, 337 "CMOS RAM" on PCs, "NVRAM" on Ataris and "PRAM" on Macintoshes. 338 339 To compile this driver as a module, choose M here: the 340 module will be called nvram. 341 342 config DEVPORT 343 bool "/dev/port character device" 344 depends on HAS_IOPORT 345 default y 346 help 347 Say Y here if you want to support the /dev/port device. The /dev/port 348 device is similar to /dev/mem, but for I/O ports. 349 350 config HPET 351 bool "HPET - High Precision Event Timer" if X86 352 default n 353 depends on ACPI 354 help 355 If you say Y here, you will have a miscdevice named "/dev/hpet/". Each 356 open selects one of the timers supported by the HPET. The timers are 357 non-periodic and/or periodic. 358 359 config HPET_MMAP 360 bool "Allow mmap of HPET" 361 default y 362 depends on HPET 363 help 364 If you say Y here, user applications will be able to mmap 365 the HPET registers. 366 367 config HPET_MMAP_DEFAULT 368 bool "Enable HPET MMAP access by default" 369 default y 370 depends on HPET_MMAP 371 help 372 In some hardware implementations, the page containing HPET 373 registers may also contain other things that shouldn't be 374 exposed to the user. This option selects the default (if 375 kernel parameter hpet_mmap is not set) user access to the 376 registers for applications that require it. 377 378 config HANGCHECK_TIMER 379 tristate "Hangcheck timer" 380 depends on X86 || PPC64 || S390 381 help 382 The hangcheck-timer module detects when the system has gone 383 out to lunch past a certain margin. It can reboot the system 384 or merely print a warning. 385 386 config UV_MMTIMER 387 tristate "UV_MMTIMER Memory mapped RTC for SGI UV" 388 depends on X86_UV 389 default m 390 help 391 The uv_mmtimer device allows direct userspace access to the 392 UV system timer. 393 394 source "drivers/char/tpm/Kconfig" 395 396 config TELCLOCK 397 tristate "Telecom clock driver for ATCA SBC" 398 depends on X86 399 default n 400 help 401 The telecom clock device is specific to the MPCBL0010 and MPCBL0050 402 ATCA computers and allows direct userspace access to the 403 configuration of the telecom clock configuration settings. This 404 device is used for hardware synchronization across the ATCA backplane 405 fabric. Upon loading, the driver exports a sysfs directory, 406 /sys/devices/platform/telco_clock, with a number of files for 407 controlling the behavior of this hardware. 408 409 source "drivers/s390/char/Kconfig" 410 411 source "drivers/char/xillybus/Kconfig" 412 413 config ADI 414 tristate "SPARC Privileged ADI driver" 415 depends on SPARC64 416 default m 417 help 418 SPARC M7 and newer processors utilize ADI (Application Data 419 Integrity) to version and protect memory. This driver provides 420 read/write access to the ADI versions for privileged processes. 421 This feature is also known as MCD (Memory Corruption Detection) 422 and SSM (Silicon Secured Memory). Intended consumers of this 423 driver include crash and makedumpfile. 424 425 endmenu 426