Commit | Line | Data |
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b2441318 | 1 | # SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | # |
3 | # Character device configuration | |
4 | # | |
5 | ||
6 | menu "Character devices" | |
7 | ||
bdcffc5a | 8 | source "drivers/tty/Kconfig" |
13ae6645 | 9 | |
24b4b67d | 10 | config TTY_PRINTK |
b24313a8 | 11 | tristate "TTY driver to output user messages via printk" |
4f73bc4d | 12 | depends on EXPERT && TTY |
24b4b67d | 13 | default n |
a7f7f624 | 14 | help |
24b4b67d SP |
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 | |
7ea4aa70 VW |
21 | to /dev/ttyprintk or redirect console to this TTY, or boot |
22 | the kernel with console=ttyprintk. | |
24b4b67d SP |
23 | |
24 | If unsure, say N. | |
25 | ||
acef6660 PK |
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 | ||
1da177e4 LT |
34 | config PRINTER |
35 | tristate "Parallel printer support" | |
36 | depends on PARPORT | |
a7f7f624 | 37 | help |
1da177e4 LT |
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 | |
4e74eeb2 | 42 | <https://www.tldp.org/docs.html#howto>. |
1da177e4 LT |
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 | |
5fb94e9c | 49 | <file:Documentation/admin-guide/parport.rst>. The module will be called lp. |
1da177e4 LT |
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 | ||
60 | config LP_CONSOLE | |
61 | bool "Support for console on line printer" | |
62 | depends on PRINTER | |
a7f7f624 | 63 | help |
1da177e4 LT |
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 | ||
77 | config PPDEV | |
78 | tristate "Support for user-space parallel port device drivers" | |
79 | depends on PARPORT | |
a7f7f624 | 80 | help |
1da177e4 LT |
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 | ||
31610434 | 95 | config VIRTIO_CONSOLE |
7721c494 | 96 | tristate "Virtio console" |
9f30eb29 | 97 | depends on TTY |
31610434 | 98 | select HVC_DRIVER |
9f30eb29 | 99 | select VIRTIO |
7721c494 | 100 | help |
ecda85e7 | 101 | Virtio console for use with hypervisors. |
7721c494 | 102 | |
fb08bd27 AS |
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. | |
31610434 | 111 | |
fe9e8d53 SR |
112 | config 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 | ||
43a1dd9b SJS |
120 | config 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 | ||
1da177e4 LT |
134 | source "drivers/char/ipmi/Kconfig" |
135 | ||
1da177e4 LT |
136 | config 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 | ||
148 | config NWBUTTON | |
149 | tristate "NetWinder Button" | |
150 | depends on ARCH_NETWINDER | |
a7f7f624 | 151 | help |
1da177e4 LT |
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 | ||
172 | config 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 | ||
184 | config NWFLASH | |
185 | tristate "NetWinder flash support" | |
186 | depends on ARCH_NETWINDER | |
a7f7f624 | 187 | help |
1da177e4 LT |
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 | ||
844dd05f MB |
199 | source "drivers/char/hw_random/Kconfig" |
200 | ||
1da177e4 LT |
201 | config DTLK |
202 | tristate "Double Talk PC internal speech card support" | |
eeca7a36 | 203 | depends on ISA |
1da177e4 LT |
204 | help |
205 | This driver is for the DoubleTalk PC, a speech synthesizer | |
4e74eeb2 | 206 | manufactured by RC Systems (<https://www.rcsys.com/>). It is also |
1da177e4 LT |
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 | ||
ef141a0b SN |
212 | config XILINX_HWICAP |
213 | tristate "Xilinx HWICAP Support" | |
7ade8495 | 214 | depends on MICROBLAZE |
ef141a0b SN |
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 | ||
1da177e4 LT |
222 | config APPLICOM |
223 | tristate "Applicom intelligent fieldbus card support" | |
224 | depends on PCI | |
a7f7f624 | 225 | help |
1da177e4 LT |
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 | |
4e74eeb2 | 229 | <https://www.applicom-int.com/>, or by email from David Woodhouse |
1da177e4 LT |
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 | ||
237 | config SONYPI | |
65929215 | 238 | tristate "Sony Vaio Programmable I/O Control Device support" |
57dcf020 | 239 | depends on X86_32 && PCI && INPUT |
a7f7f624 | 240 | help |
1da177e4 LT |
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 | |
9e1cbede | 245 | <file:Documentation/admin-guide/laptops/sonypi.rst>, and say Y or M here. |
1da177e4 LT |
246 | |
247 | To compile this driver as a module, choose M here: the | |
248 | module will be called sonypi. | |
249 | ||
1da177e4 LT |
250 | source "drivers/char/pcmcia/Kconfig" |
251 | ||
252 | config MWAVE | |
253 | tristate "ACP Modem (Mwave) support" | |
4f73bc4d | 254 | depends on X86 && TTY |
1da177e4 | 255 | select SERIAL_8250 |
a7f7f624 | 256 | help |
1da177e4 LT |
257 | The ACP modem (Mwave) for Linux is a WinModem. It is composed of a |
258 | kernel driver and a user level application. Together these components | |
259 | support direct attachment to public switched telephone networks (PSTNs) | |
260 | and support selected world wide countries. | |
261 | ||
262 | This version of the ACP Modem driver supports the IBM Thinkpad 600E, | |
263 | 600, and 770 that include on board ACP modem hardware. | |
264 | ||
265 | The modem also supports the standard communications port interface | |
266 | (ttySx) and is compatible with the Hayes AT Command Set. | |
267 | ||
268 | The user level application needed to use this driver can be found at | |
269 | the IBM Linux Technology Center (LTC) web site: | |
270 | <http://www.ibm.com/linux/ltc/>. | |
271 | ||
272 | If you own one of the above IBM Thinkpads which has the Mwave chipset | |
273 | in it, say Y. | |
274 | ||
275 | To compile this driver as a module, choose M here: the | |
276 | module will be called mwave. | |
277 | ||
278 | config SCx200_GPIO | |
279 | tristate "NatSemi SCx200 GPIO Support" | |
280 | depends on SCx200 | |
7a8e2a5e | 281 | select NSC_GPIO |
1da177e4 LT |
282 | help |
283 | Give userspace access to the GPIO pins on the National | |
284 | Semiconductor SCx200 processors. | |
285 | ||
286 | If compiled as a module, it will be called scx200_gpio. | |
287 | ||
7a8e2a5e JC |
288 | config PC8736x_GPIO |
289 | tristate "NatSemi PC8736x GPIO Support" | |
3369465e | 290 | depends on X86_32 && !UML |
7a8e2a5e JC |
291 | default SCx200_GPIO # mostly N |
292 | select NSC_GPIO # needed for support routines | |
293 | help | |
294 | Give userspace access to the GPIO pins on the National | |
295 | Semiconductor PC-8736x (x=[03456]) SuperIO chip. The chip | |
296 | has multiple functional units, inc several managed by | |
297 | hwmon/pc87360 driver. Tested with PC-87366 | |
298 | ||
299 | If compiled as a module, it will be called pc8736x_gpio. | |
300 | ||
301 | config NSC_GPIO | |
302 | tristate "NatSemi Base GPIO Support" | |
699352c3 | 303 | depends on X86_32 |
7a8e2a5e JC |
304 | # selected by SCx200_GPIO and PC8736x_GPIO |
305 | # what about 2 selectors differing: m != y | |
306 | help | |
307 | Common support used (and needed) by scx200_gpio and | |
308 | pc8736x_gpio drivers. If those drivers are built as | |
309 | modules, this one will be too, named nsc_gpio | |
310 | ||
8d7dc56e RD |
311 | config DEVMEM |
312 | bool "/dev/mem virtual device support" | |
313 | default y | |
314 | help | |
315 | Say Y here if you want to support the /dev/mem device. | |
316 | The /dev/mem device is used to access areas of physical | |
317 | memory. | |
318 | When in doubt, say "Y". | |
319 | ||
8d7dc56e RD |
320 | config NVRAM |
321 | tristate "/dev/nvram support" | |
322 | depends on X86 || HAVE_ARCH_NVRAM_OPS | |
323 | default M68K || PPC | |
a7f7f624 | 324 | help |
8d7dc56e RD |
325 | If you say Y here and create a character special file /dev/nvram |
326 | with major number 10 and minor number 144 using mknod ("man mknod"), | |
327 | you get read and write access to the non-volatile memory. | |
328 | ||
329 | /dev/nvram may be used to view settings in NVRAM or to change them | |
330 | (with some utility). It could also be used to frequently | |
331 | save a few bits of very important data that may not be lost over | |
332 | power-off and for which writing to disk is too insecure. Note | |
333 | however that most NVRAM space in a PC belongs to the BIOS and you | |
334 | should NEVER idly tamper with it. See Ralf Brown's interrupt list | |
335 | for a guide to the use of CMOS bytes by your BIOS. | |
336 | ||
337 | This memory is conventionally called "NVRAM" on PowerPC machines, | |
338 | "CMOS RAM" on PCs, "NVRAM" on Ataris and "PRAM" on Macintoshes. | |
339 | ||
340 | To compile this driver as a module, choose M here: the | |
341 | module will be called nvram. | |
342 | ||
8d7dc56e RD |
343 | config DEVPORT |
344 | bool "/dev/port character device" | |
345 | depends on ISA || PCI | |
346 | default y | |
347 | help | |
348 | Say Y here if you want to support the /dev/port device. The /dev/port | |
349 | device is similar to /dev/mem, but for I/O ports. | |
350 | ||
1da177e4 LT |
351 | config HPET |
352 | bool "HPET - High Precision Event Timer" if (X86 || IA64) | |
353 | default n | |
354 | depends on ACPI | |
355 | help | |
356 | If you say Y here, you will have a miscdevice named "/dev/hpet/". Each | |
357 | open selects one of the timers supported by the HPET. The timers are | |
3cb2fccc | 358 | non-periodic and/or periodic. |
1da177e4 | 359 | |
1da177e4 LT |
360 | config HPET_MMAP |
361 | bool "Allow mmap of HPET" | |
362 | default y | |
363 | depends on HPET | |
364 | help | |
365 | If you say Y here, user applications will be able to mmap | |
366 | the HPET registers. | |
367 | ||
3d035f58 PB |
368 | config HPET_MMAP_DEFAULT |
369 | bool "Enable HPET MMAP access by default" | |
370 | default y | |
371 | depends on HPET_MMAP | |
372 | help | |
1da177e4 LT |
373 | In some hardware implementations, the page containing HPET |
374 | registers may also contain other things that shouldn't be | |
3d035f58 PB |
375 | exposed to the user. This option selects the default (if |
376 | kernel parameter hpet_mmap is not set) user access to the | |
377 | registers for applications that require it. | |
1da177e4 | 378 | |
1da177e4 LT |
379 | config HANGCHECK_TIMER |
380 | tristate "Hangcheck timer" | |
abf3ea1b | 381 | depends on X86 || IA64 || PPC64 || S390 |
1da177e4 LT |
382 | help |
383 | The hangcheck-timer module detects when the system has gone | |
384 | out to lunch past a certain margin. It can reboot the system | |
385 | or merely print a warning. | |
386 | ||
fbd8ae10 DS |
387 | config UV_MMTIMER |
388 | tristate "UV_MMTIMER Memory mapped RTC for SGI UV" | |
389 | depends on X86_UV | |
390 | default m | |
391 | help | |
392 | The uv_mmtimer device allows direct userspace access to the | |
393 | UV system timer. | |
394 | ||
1da177e4 LT |
395 | source "drivers/char/tpm/Kconfig" |
396 | ||
1a80ba88 | 397 | config TELCLOCK |
03154a27 | 398 | tristate "Telecom clock driver for ATCA SBC" |
65929215 | 399 | depends on X86 |
1a80ba88 MG |
400 | default n |
401 | help | |
03154a27 MG |
402 | The telecom clock device is specific to the MPCBL0010 and MPCBL0050 |
403 | ATCA computers and allows direct userspace access to the | |
404 | configuration of the telecom clock configuration settings. This | |
405 | device is used for hardware synchronization across the ATCA backplane | |
406 | fabric. Upon loading, the driver exports a sysfs directory, | |
407 | /sys/devices/platform/telco_clock, with a number of files for | |
408 | controlling the behavior of this hardware. | |
1a80ba88 | 409 | |
61d48c2c MS |
410 | source "drivers/s390/char/Kconfig" |
411 | ||
7051924f EB |
412 | source "drivers/char/xillybus/Kconfig" |
413 | ||
873c38a4 TH |
414 | config ADI |
415 | tristate "SPARC Privileged ADI driver" | |
416 | depends on SPARC64 | |
417 | default m | |
418 | help | |
419 | SPARC M7 and newer processors utilize ADI (Application Data | |
420 | Integrity) to version and protect memory. This driver provides | |
421 | read/write access to the ADI versions for privileged processes. | |
422 | This feature is also known as MCD (Memory Corruption Detection) | |
423 | and SSM (Silicon Secured Memory). Intended consumers of this | |
424 | driver include crash and makedumpfile. | |
425 | ||
39a8883a | 426 | config RANDOM_TRUST_CPU |
846bb97e JD |
427 | bool "Initialize RNG using CPU RNG instructions" |
428 | default y | |
39a8883a | 429 | help |
846bb97e JD |
430 | Initialize the RNG using random numbers supplied by the CPU's |
431 | RNG instructions (e.g. RDRAND), if supported and available. These | |
432 | random numbers are never used directly, but are rather hashed into | |
433 | the main input pool, and this happens regardless of whether or not | |
434 | this option is enabled. Instead, this option controls whether the | |
435 | they are credited and hence can initialize the RNG. Additionally, | |
436 | other sources of randomness are always used, regardless of this | |
437 | setting. Enabling this implies trusting that the CPU can supply high | |
438 | quality and non-backdoored random numbers. | |
439 | ||
440 | Say Y here unless you have reason to mistrust your CPU or believe | |
441 | its RNG facilities may be faulty. This may also be configured at | |
442 | boot time with "random.trust_cpu=on/off". | |
428826f5 HYW |
443 | |
444 | config RANDOM_TRUST_BOOTLOADER | |
846bb97e JD |
445 | bool "Initialize RNG using bootloader-supplied seed" |
446 | default y | |
447 | help | |
448 | Initialize the RNG using a seed supplied by the bootloader or boot | |
449 | environment (e.g. EFI or a bootloader-generated device tree). This | |
450 | seed is not used directly, but is rather hashed into the main input | |
451 | pool, and this happens regardless of whether or not this option is | |
452 | enabled. Instead, this option controls whether the seed is credited | |
453 | and hence can initialize the RNG. Additionally, other sources of | |
454 | randomness are always used, regardless of this setting. Enabling | |
455 | this implies trusting that the bootloader can supply high quality and | |
456 | non-backdoored seeds. | |
457 | ||
458 | Say Y here unless you have reason to mistrust your bootloader or | |
459 | believe its RNG facilities may be faulty. This may also be configured | |
460 | at boot time with "random.trust_bootloader=on/off". | |
9e1b28b7 RD |
461 | |
462 | endmenu |