Linux kernel mirror (for testing)
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tjh.dev
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linux
1# SPDX-License-Identifier: GPL-2.0
2#
3# Character device configuration
4#
5
6menu "Character devices"
7
8source "drivers/tty/Kconfig"
9
10config 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
26config 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
34config PRINTER
35 tristate "Parallel printer support"
36 depends on PARPORT
37 help
38 If you intend to attach a printer to the parallel port of your Linux
39 box (as opposed to using a serial printer; if the connector at the
40 printer has 9 or 25 holes ["female"], then it's serial), say Y.
41 Also read the Printing-HOWTO, available from
42 <https://www.tldp.org/docs.html#howto>.
43
44 It is possible to share one parallel port among several devices
45 (e.g. printer and ZIP drive) and it is safe to compile the
46 corresponding drivers into the kernel.
47
48 To compile this driver as a module, choose M here and read
49 <file:Documentation/admin-guide/parport.rst>. The module will be called lp.
50
51 If you have several parallel ports, you can specify which ports to
52 use with the "lp" kernel command line option. (Try "man bootparam"
53 or see the documentation of your boot loader (lilo or loadlin) about
54 how to pass options to the kernel at boot time.) The syntax of the
55 "lp" command line option can be found in <file:drivers/char/lp.c>.
56
57 If you have more than 8 printers, you need to increase the LP_NO
58 macro in lp.c and the PARPORT_MAX macro in parport.h.
59
60config LP_CONSOLE
61 bool "Support for console on line printer"
62 depends on PRINTER
63 help
64 If you want kernel messages to be printed out as they occur, you
65 can have a console on the printer. This option adds support for
66 doing that; to actually get it to happen you need to pass the
67 option "console=lp0" to the kernel at boot time.
68
69 If the printer is out of paper (or off, or unplugged, or too
70 busy..) the kernel will stall until the printer is ready again.
71 By defining CONSOLE_LP_STRICT to 0 (at your own risk) you
72 can make the kernel continue when this happens,
73 but it'll lose the kernel messages.
74
75 If unsure, say N.
76
77config PPDEV
78 tristate "Support for user-space parallel port device drivers"
79 depends on PARPORT
80 help
81 Saying Y to this adds support for /dev/parport device nodes. This
82 is needed for programs that want portable access to the parallel
83 port, for instance deviceid (which displays Plug-and-Play device
84 IDs).
85
86 This is the parallel port equivalent of SCSI generic support (sg).
87 It is safe to say N to this -- it is not needed for normal printing
88 or parallel port CD-ROM/disk support.
89
90 To compile this driver as a module, choose M here: the
91 module will be called ppdev.
92
93 If unsure, say N.
94
95config VIRTIO_CONSOLE
96 tristate "Virtio console"
97 depends on TTY
98 select HVC_DRIVER
99 select VIRTIO
100 help
101 Virtio console for use with hypervisors.
102
103 Also serves as a general-purpose serial device for data
104 transfer between the guest and host. Character devices at
105 /dev/vportNpn will be created when corresponding ports are
106 found, where N is the device number and n is the port number
107 within that device. If specified by the host, a sysfs
108 attribute called 'name' will be populated with a name for
109 the port which can be used by udev scripts to create a
110 symlink to the device.
111
112config IBM_BSR
113 tristate "IBM POWER Barrier Synchronization Register support"
114 depends on PPC_PSERIES
115 help
116 This devices exposes a hardware mechanism for fast synchronization
117 of threads across a large system which avoids bouncing a cacheline
118 between several cores on a system
119
120config POWERNV_OP_PANEL
121 tristate "IBM POWERNV Operator Panel Display support"
122 depends on PPC_POWERNV
123 default m
124 help
125 If you say Y here, a special character device node, /dev/op_panel,
126 will be created which exposes the operator panel display on IBM
127 Power Systems machines with FSPs.
128
129 If you don't require access to the operator panel display from user
130 space, say N.
131
132 If unsure, say M here to build it as a module called powernv-op-panel.
133
134source "drivers/char/ipmi/Kconfig"
135
136config DS1620
137 tristate "NetWinder thermometer support"
138 depends on ARCH_NETWINDER
139 help
140 Say Y here to include support for the thermal management hardware
141 found in the NetWinder. This driver allows the user to control the
142 temperature set points and to read the current temperature.
143
144 It is also possible to say M here to build it as a module (ds1620)
145 It is recommended to be used on a NetWinder, but it is not a
146 necessity.
147
148config NWBUTTON
149 tristate "NetWinder Button"
150 depends on ARCH_NETWINDER
151 help
152 If you say Y here and create a character device node /dev/nwbutton
153 with major and minor numbers 10 and 158 ("man mknod"), then every
154 time the orange button is pressed a number of times, the number of
155 times the button was pressed will be written to that device.
156
157 This is most useful for applications, as yet unwritten, which
158 perform actions based on how many times the button is pressed in a
159 row.
160
161 Do not hold the button down for too long, as the driver does not
162 alter the behaviour of the hardware reset circuitry attached to the
163 button; it will still execute a hard reset if the button is held
164 down for longer than approximately five seconds.
165
166 To compile this driver as a module, choose M here: the
167 module will be called nwbutton.
168
169 Most people will answer Y to this question and "Reboot Using Button"
170 below to be able to initiate a system shutdown from the button.
171
172config NWBUTTON_REBOOT
173 bool "Reboot Using Button"
174 depends on NWBUTTON
175 help
176 If you say Y here, then you will be able to initiate a system
177 shutdown and reboot by pressing the orange button a number of times.
178 The number of presses to initiate the shutdown is two by default,
179 but this can be altered by modifying the value of NUM_PRESSES_REBOOT
180 in nwbutton.h and recompiling the driver or, if you compile the
181 driver as a module, you can specify the number of presses at load
182 time with "insmod button reboot_count=<something>".
183
184config NWFLASH
185 tristate "NetWinder flash support"
186 depends on ARCH_NETWINDER
187 help
188 If you say Y here and create a character device /dev/flash with
189 major 10 and minor 160 you can manipulate the flash ROM containing
190 the NetWinder firmware. Be careful as accidentally overwriting the
191 flash contents can render your computer unbootable. On no account
192 allow random users access to this device. :-)
193
194 To compile this driver as a module, choose M here: the
195 module will be called nwflash.
196
197 If you're not sure, say N.
198
199source "drivers/char/hw_random/Kconfig"
200
201config DTLK
202 tristate "Double Talk PC internal speech card support"
203 depends on ISA
204 help
205 This driver is for the DoubleTalk PC, a speech synthesizer
206 manufactured by RC Systems (<https://www.rcsys.com/>). It is also
207 called the `internal DoubleTalk'.
208
209 To compile this driver as a module, choose M here: the
210 module will be called dtlk.
211
212config XILINX_HWICAP
213 tristate "Xilinx HWICAP Support"
214 depends on MICROBLAZE
215 help
216 This option enables support for Xilinx Internal Configuration
217 Access Port (ICAP) driver. The ICAP is used on Xilinx Virtex
218 FPGA platforms to partially reconfigure the FPGA at runtime.
219
220 If unsure, say N.
221
222config APPLICOM
223 tristate "Applicom intelligent fieldbus card support"
224 depends on PCI
225 help
226 This driver provides the kernel-side support for the intelligent
227 fieldbus cards made by Applicom International. More information
228 about these cards can be found on the WWW at the address
229 <https://www.applicom-int.com/>, or by email from David Woodhouse
230 <dwmw2@infradead.org>.
231
232 To compile this driver as a module, choose M here: the
233 module will be called applicom.
234
235 If unsure, say N.
236
237config SONYPI
238 tristate "Sony Vaio Programmable I/O Control Device support"
239 depends on X86_32 && PCI && INPUT
240 help
241 This driver enables access to the Sony Programmable I/O Control
242 Device which can be found in many (all ?) Sony Vaio laptops.
243
244 If you have one of those laptops, read
245 <file:Documentation/admin-guide/laptops/sonypi.rst>, and say Y or M here.
246
247 To compile this driver as a module, choose M here: the
248 module will be called sonypi.
249
250config GPIO_TB0219
251 tristate "TANBAC TB0219 GPIO support"
252 depends on TANBAC_TB022X
253 select GPIO_VR41XX
254
255source "drivers/char/pcmcia/Kconfig"
256
257config MWAVE
258 tristate "ACP Modem (Mwave) support"
259 depends on X86 && TTY
260 select SERIAL_8250
261 help
262 The ACP modem (Mwave) for Linux is a WinModem. It is composed of a
263 kernel driver and a user level application. Together these components
264 support direct attachment to public switched telephone networks (PSTNs)
265 and support selected world wide countries.
266
267 This version of the ACP Modem driver supports the IBM Thinkpad 600E,
268 600, and 770 that include on board ACP modem hardware.
269
270 The modem also supports the standard communications port interface
271 (ttySx) and is compatible with the Hayes AT Command Set.
272
273 The user level application needed to use this driver can be found at
274 the IBM Linux Technology Center (LTC) web site:
275 <http://www.ibm.com/linux/ltc/>.
276
277 If you own one of the above IBM Thinkpads which has the Mwave chipset
278 in it, say Y.
279
280 To compile this driver as a module, choose M here: the
281 module will be called mwave.
282
283config SCx200_GPIO
284 tristate "NatSemi SCx200 GPIO Support"
285 depends on SCx200
286 select NSC_GPIO
287 help
288 Give userspace access to the GPIO pins on the National
289 Semiconductor SCx200 processors.
290
291 If compiled as a module, it will be called scx200_gpio.
292
293config PC8736x_GPIO
294 tristate "NatSemi PC8736x GPIO Support"
295 depends on X86_32 && !UML
296 default SCx200_GPIO # mostly N
297 select NSC_GPIO # needed for support routines
298 help
299 Give userspace access to the GPIO pins on the National
300 Semiconductor PC-8736x (x=[03456]) SuperIO chip. The chip
301 has multiple functional units, inc several managed by
302 hwmon/pc87360 driver. Tested with PC-87366
303
304 If compiled as a module, it will be called pc8736x_gpio.
305
306config NSC_GPIO
307 tristate "NatSemi Base GPIO Support"
308 depends on X86_32
309 # selected by SCx200_GPIO and PC8736x_GPIO
310 # what about 2 selectors differing: m != y
311 help
312 Common support used (and needed) by scx200_gpio and
313 pc8736x_gpio drivers. If those drivers are built as
314 modules, this one will be too, named nsc_gpio
315
316config DEVMEM
317 bool "/dev/mem virtual device support"
318 default y
319 help
320 Say Y here if you want to support the /dev/mem device.
321 The /dev/mem device is used to access areas of physical
322 memory.
323 When in doubt, say "Y".
324
325config NVRAM
326 tristate "/dev/nvram support"
327 depends on X86 || HAVE_ARCH_NVRAM_OPS
328 default M68K || PPC
329 help
330 If you say Y here and create a character special file /dev/nvram
331 with major number 10 and minor number 144 using mknod ("man mknod"),
332 you get read and write access to the non-volatile memory.
333
334 /dev/nvram may be used to view settings in NVRAM or to change them
335 (with some utility). It could also be used to frequently
336 save a few bits of very important data that may not be lost over
337 power-off and for which writing to disk is too insecure. Note
338 however that most NVRAM space in a PC belongs to the BIOS and you
339 should NEVER idly tamper with it. See Ralf Brown's interrupt list
340 for a guide to the use of CMOS bytes by your BIOS.
341
342 This memory is conventionally called "NVRAM" on PowerPC machines,
343 "CMOS RAM" on PCs, "NVRAM" on Ataris and "PRAM" on Macintoshes.
344
345 To compile this driver as a module, choose M here: the
346 module will be called nvram.
347
348config DEVPORT
349 bool "/dev/port character device"
350 depends on ISA || PCI
351 default y
352 help
353 Say Y here if you want to support the /dev/port device. The /dev/port
354 device is similar to /dev/mem, but for I/O ports.
355
356config HPET
357 bool "HPET - High Precision Event Timer" if (X86 || IA64)
358 default n
359 depends on ACPI
360 help
361 If you say Y here, you will have a miscdevice named "/dev/hpet/". Each
362 open selects one of the timers supported by the HPET. The timers are
363 non-periodic and/or periodic.
364
365config HPET_MMAP
366 bool "Allow mmap of HPET"
367 default y
368 depends on HPET
369 help
370 If you say Y here, user applications will be able to mmap
371 the HPET registers.
372
373config HPET_MMAP_DEFAULT
374 bool "Enable HPET MMAP access by default"
375 default y
376 depends on HPET_MMAP
377 help
378 In some hardware implementations, the page containing HPET
379 registers may also contain other things that shouldn't be
380 exposed to the user. This option selects the default (if
381 kernel parameter hpet_mmap is not set) user access to the
382 registers for applications that require it.
383
384config HANGCHECK_TIMER
385 tristate "Hangcheck timer"
386 depends on X86 || IA64 || PPC64 || S390
387 help
388 The hangcheck-timer module detects when the system has gone
389 out to lunch past a certain margin. It can reboot the system
390 or merely print a warning.
391
392config UV_MMTIMER
393 tristate "UV_MMTIMER Memory mapped RTC for SGI UV"
394 depends on X86_UV
395 default m
396 help
397 The uv_mmtimer device allows direct userspace access to the
398 UV system timer.
399
400source "drivers/char/tpm/Kconfig"
401
402config TELCLOCK
403 tristate "Telecom clock driver for ATCA SBC"
404 depends on X86
405 default n
406 help
407 The telecom clock device is specific to the MPCBL0010 and MPCBL0050
408 ATCA computers and allows direct userspace access to the
409 configuration of the telecom clock configuration settings. This
410 device is used for hardware synchronization across the ATCA backplane
411 fabric. Upon loading, the driver exports a sysfs directory,
412 /sys/devices/platform/telco_clock, with a number of files for
413 controlling the behavior of this hardware.
414
415source "drivers/s390/char/Kconfig"
416
417source "drivers/char/xillybus/Kconfig"
418
419config ADI
420 tristate "SPARC Privileged ADI driver"
421 depends on SPARC64
422 default m
423 help
424 SPARC M7 and newer processors utilize ADI (Application Data
425 Integrity) to version and protect memory. This driver provides
426 read/write access to the ADI versions for privileged processes.
427 This feature is also known as MCD (Memory Corruption Detection)
428 and SSM (Silicon Secured Memory). Intended consumers of this
429 driver include crash and makedumpfile.
430
431config RANDOM_TRUST_CPU
432 bool "Initialize RNG using CPU RNG instructions"
433 default y
434 depends on ARCH_RANDOM
435 help
436 Initialize the RNG using random numbers supplied by the CPU's
437 RNG instructions (e.g. RDRAND), if supported and available. These
438 random numbers are never used directly, but are rather hashed into
439 the main input pool, and this happens regardless of whether or not
440 this option is enabled. Instead, this option controls whether the
441 they are credited and hence can initialize the RNG. Additionally,
442 other sources of randomness are always used, regardless of this
443 setting. Enabling this implies trusting that the CPU can supply high
444 quality and non-backdoored random numbers.
445
446 Say Y here unless you have reason to mistrust your CPU or believe
447 its RNG facilities may be faulty. This may also be configured at
448 boot time with "random.trust_cpu=on/off".
449
450config RANDOM_TRUST_BOOTLOADER
451 bool "Initialize RNG using bootloader-supplied seed"
452 default y
453 help
454 Initialize the RNG using a seed supplied by the bootloader or boot
455 environment (e.g. EFI or a bootloader-generated device tree). This
456 seed is not used directly, but is rather hashed into the main input
457 pool, and this happens regardless of whether or not this option is
458 enabled. Instead, this option controls whether the seed is credited
459 and hence can initialize the RNG. Additionally, other sources of
460 randomness are always used, regardless of this setting. Enabling
461 this implies trusting that the bootloader can supply high quality and
462 non-backdoored seeds.
463
464 Say Y here unless you have reason to mistrust your bootloader or
465 believe its RNG facilities may be faulty. This may also be configured
466 at boot time with "random.trust_bootloader=on/off".
467
468endmenu