2 # Character device configuration
5 menu "Character devices"
7 source "drivers/tty/Kconfig"
10 bool "Memory device driver"
13 The memory driver provides two character devices, mem and kmem, which
14 provide access to the system's memory. The mem device is a view of
15 physical memory, and each byte in the device corresponds to the
16 matching physical address. The kmem device is the same as mem, but
17 the addresses correspond to the kernel's virtual address space rather
18 than physical memory. These devices are standard parts of a Linux
19 system and most users should say Y here. You might say N if very
20 security conscience or memory is tight.
23 bool "/dev/kmem virtual device support"
26 Say Y here if you want to support the /dev/kmem device. The
27 /dev/kmem device is rarely used, but can be used for certain
28 kind of kernel debugging operations.
29 When in doubt, say "N".
32 bool "Stallion multiport serial support"
33 depends on SERIAL_NONSTANDARD
35 Stallion cards give you many serial ports. You would need something
36 like this to connect more than two modems to your Linux box, for
37 instance in order to become a dial-in server. If you say Y here,
38 you will be asked for your specific card model in the next
39 questions. Make sure to read <file:Documentation/serial/stallion.txt>
40 in this case. If you have never heard about all this, it's safe to
44 bool "SGI Altix system controller communication support"
45 depends on (IA64_SGI_SN2 || IA64_GENERIC)
47 If you have an SGI Altix and you want to enable system
48 controller communication from user space (you want this!),
49 say Y. Otherwise, say N.
52 bool "SGI TIO CX driver support"
53 depends on (IA64_SGI_SN2 || IA64_GENERIC)
55 If you have an SGI Altix and you have fpga devices attached
56 to your TIO, say Y here, otherwise say N.
59 tristate "SGI FPGA Core Services driver support"
62 If you have an SGI Altix with an attached SABrick
63 say Y or M here, otherwise say N.
65 source "drivers/tty/serial/Kconfig"
68 bool "TTY driver to output user messages via printk"
69 depends on EXPERT && TTY
72 If you say Y here, the support for writing user messages (i.e.
73 console messages) via printk is available.
75 The feature is useful to inline user messages with kernel
77 In order to use this feature, you should output user messages
78 to /dev/ttyprintk or redirect console to this TTY.
83 tristate "Blackfin On-Chip OTP Memory Support"
84 depends on BLACKFIN && (BF51x || BF52x || BF54x)
87 If you say Y here, you will get support for a character device
88 interface into the One Time Programmable memory pages that are
89 stored on the Blackfin processor. This will not get you access
90 to the secure memory pages however. You will need to write your
91 own secure code and reader for that.
93 To compile this driver as a module, choose M here: the module
94 will be called bfin-otp.
96 If unsure, it is safe to say Y.
98 config BFIN_OTP_WRITE_ENABLE
99 bool "Enable writing support of OTP pages"
103 If you say Y here, you will enable support for writing of the
104 OTP pages. This is dangerous by nature as you can only program
105 the pages once, so only enable this option when you actually
106 need it so as to not inadvertently clobber data.
111 tristate "Parallel printer support"
114 If you intend to attach a printer to the parallel port of your Linux
115 box (as opposed to using a serial printer; if the connector at the
116 printer has 9 or 25 holes ["female"], then it's serial), say Y.
117 Also read the Printing-HOWTO, available from
118 <http://www.tldp.org/docs.html#howto>.
120 It is possible to share one parallel port among several devices
121 (e.g. printer and ZIP drive) and it is safe to compile the
122 corresponding drivers into the kernel.
124 To compile this driver as a module, choose M here and read
125 <file:Documentation/parport.txt>. The module will be called lp.
127 If you have several parallel ports, you can specify which ports to
128 use with the "lp" kernel command line option. (Try "man bootparam"
129 or see the documentation of your boot loader (lilo or loadlin) about
130 how to pass options to the kernel at boot time.) The syntax of the
131 "lp" command line option can be found in <file:drivers/char/lp.c>.
133 If you have more than 8 printers, you need to increase the LP_NO
134 macro in lp.c and the PARPORT_MAX macro in parport.h.
137 bool "Support for console on line printer"
140 If you want kernel messages to be printed out as they occur, you
141 can have a console on the printer. This option adds support for
142 doing that; to actually get it to happen you need to pass the
143 option "console=lp0" to the kernel at boot time.
145 If the printer is out of paper (or off, or unplugged, or too
146 busy..) the kernel will stall until the printer is ready again.
147 By defining CONSOLE_LP_STRICT to 0 (at your own risk) you
148 can make the kernel continue when this happens,
149 but it'll lose the kernel messages.
154 tristate "Support for user-space parallel port device drivers"
157 Saying Y to this adds support for /dev/parport device nodes. This
158 is needed for programs that want portable access to the parallel
159 port, for instance deviceid (which displays Plug-and-Play device
162 This is the parallel port equivalent of SCSI generic support (sg).
163 It is safe to say N to this -- it is not needed for normal printing
164 or parallel port CD-ROM/disk support.
166 To compile this driver as a module, choose M here: the
167 module will be called ppdev.
171 source "drivers/tty/hvc/Kconfig"
173 config VIRTIO_CONSOLE
174 tristate "Virtio console"
175 depends on VIRTIO && TTY
178 Virtio console for use with lguest and other hypervisors.
180 Also serves as a general-purpose serial device for data
181 transfer between the guest and host. Character devices at
182 /dev/vportNpn will be created when corresponding ports are
183 found, where N is the device number and n is the port number
184 within that device. If specified by the host, a sysfs
185 attribute called 'name' will be populated with a name for
186 the port which can be used by udev scripts to create a
187 symlink to the device.
190 tristate "IBM POWER Barrier Synchronization Register support"
191 depends on PPC_PSERIES
193 This devices exposes a hardware mechanism for fast synchronization
194 of threads across a large system which avoids bouncing a cacheline
195 between several cores on a system
197 source "drivers/char/ipmi/Kconfig"
200 tristate "NetWinder thermometer support"
201 depends on ARCH_NETWINDER
203 Say Y here to include support for the thermal management hardware
204 found in the NetWinder. This driver allows the user to control the
205 temperature set points and to read the current temperature.
207 It is also possible to say M here to build it as a module (ds1620)
208 It is recommended to be used on a NetWinder, but it is not a
212 tristate "NetWinder Button"
213 depends on ARCH_NETWINDER
215 If you say Y here and create a character device node /dev/nwbutton
216 with major and minor numbers 10 and 158 ("man mknod"), then every
217 time the orange button is pressed a number of times, the number of
218 times the button was pressed will be written to that device.
220 This is most useful for applications, as yet unwritten, which
221 perform actions based on how many times the button is pressed in a
224 Do not hold the button down for too long, as the driver does not
225 alter the behaviour of the hardware reset circuitry attached to the
226 button; it will still execute a hard reset if the button is held
227 down for longer than approximately five seconds.
229 To compile this driver as a module, choose M here: the
230 module will be called nwbutton.
232 Most people will answer Y to this question and "Reboot Using Button"
233 below to be able to initiate a system shutdown from the button.
235 config NWBUTTON_REBOOT
236 bool "Reboot Using Button"
239 If you say Y here, then you will be able to initiate a system
240 shutdown and reboot by pressing the orange button a number of times.
241 The number of presses to initiate the shutdown is two by default,
242 but this can be altered by modifying the value of NUM_PRESSES_REBOOT
243 in nwbutton.h and recompiling the driver or, if you compile the
244 driver as a module, you can specify the number of presses at load
245 time with "insmod button reboot_count=<something>".
248 tristate "NetWinder flash support"
249 depends on ARCH_NETWINDER
251 If you say Y here and create a character device /dev/flash with
252 major 10 and minor 160 you can manipulate the flash ROM containing
253 the NetWinder firmware. Be careful as accidentally overwriting the
254 flash contents can render your computer unbootable. On no account
255 allow random users access to this device. :-)
257 To compile this driver as a module, choose M here: the
258 module will be called nwflash.
260 If you're not sure, say N.
262 source "drivers/char/hw_random/Kconfig"
265 tristate "/dev/nvram support"
266 depends on ATARI || X86 || (ARM && RTC_DRV_CMOS) || GENERIC_NVRAM
268 If you say Y here and create a character special file /dev/nvram
269 with major number 10 and minor number 144 using mknod ("man mknod"),
270 you get read and write access to the extra bytes of non-volatile
271 memory in the real time clock (RTC), which is contained in every PC
272 and most Ataris. The actual number of bytes varies, depending on the
273 nvram in the system, but is usually 114 (128-14 for the RTC).
275 This memory is conventionally called "CMOS RAM" on PCs and "NVRAM"
276 on Ataris. /dev/nvram may be used to view settings there, or to
277 change them (with some utility). It could also be used to frequently
278 save a few bits of very important data that may not be lost over
279 power-off and for which writing to disk is too insecure. Note
280 however that most NVRAM space in a PC belongs to the BIOS and you
281 should NEVER idly tamper with it. See Ralf Brown's interrupt list
282 for a guide to the use of CMOS bytes by your BIOS.
284 On Atari machines, /dev/nvram is always configured and does not need
287 To compile this driver as a module, choose M here: the
288 module will be called nvram.
291 # These legacy RTC drivers just cause too many conflicts with the generic
292 # RTC framework ... let's not even try to coexist any more.
297 tristate "Enhanced Real Time Clock Support (legacy PC RTC driver)"
298 depends on !PPC && !PARISC && !IA64 && !M68K && !SPARC && !FRV \
299 && !ARM && !SUPERH && !S390 && !AVR32 && !BLACKFIN && !UML
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
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
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.
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>
320 To compile this driver as a module, choose M here: the
321 module will be called rtc.
324 tristate "Enhanced Real Time Clock Support"
325 depends on SPARC32 && PCI
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
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
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>
342 To compile this driver as a module, choose M here: the
343 module will be called js-rtc.
346 tristate "Generic /dev/rtc emulation"
347 depends on RTC!=y && !IA64 && !ARM && !M32R && !MIPS && !SPARC && !FRV && !S390 && !SUPERH && !AVR32 && !BLACKFIN && !UML
349 If you say Y here and create a character special file /dev/rtc with
350 major number 10 and minor number 135 using mknod ("man mknod"), you
351 will get access to the real time clock (or hardware clock) built
354 It reports status information via the file /proc/driver/rtc and its
355 behaviour is set by various ioctls on /dev/rtc. If you enable the
356 "extended RTC operation" below it will also provide an emulation
357 for RTC_UIE which is required by some programs and may improve
358 precision in some cases.
360 To compile this driver as a module, choose M here: the
361 module will be called genrtc.
364 bool "Extended RTC operation"
367 Provides an emulation for RTC_UIE which is required by some programs
368 and may improve precision of the generic RTC support in some cases.
371 bool "EFI Real Time Clock Services"
375 tristate "DS1302 RTC support"
376 depends on M32R && (PLAT_M32700UT || PLAT_OPSPUT)
378 If you say Y here and create a character special file /dev/rtc with
379 major number 121 and minor number 0 using mknod ("man mknod"), you
380 will get access to the real time clock (or hardware clock) built
386 tristate "Double Talk PC internal speech card support"
389 This driver is for the DoubleTalk PC, a speech synthesizer
390 manufactured by RC Systems (<http://www.rcsys.com/>). It is also
391 called the `internal DoubleTalk'.
393 To compile this driver as a module, choose M here: the
394 module will be called dtlk.
397 tristate "Xilinx HWICAP Support"
398 depends on XILINX_VIRTEX || MICROBLAZE
400 This option enables support for Xilinx Internal Configuration
401 Access Port (ICAP) driver. The ICAP is used on Xilinx Virtex
402 FPGA platforms to partially reconfigure the FPGA at runtime.
407 tristate "Siemens R3964 line discipline"
410 This driver allows synchronous communication with devices using the
411 Siemens R3964 packet protocol. Unless you are dealing with special
412 hardware like PLCs, you are unlikely to need this.
414 To compile this driver as a module, choose M here: the
415 module will be called n_r3964.
420 tristate "Applicom intelligent fieldbus card support"
423 This driver provides the kernel-side support for the intelligent
424 fieldbus cards made by Applicom International. More information
425 about these cards can be found on the WWW at the address
426 <http://www.applicom-int.com/>, or by email from David Woodhouse
427 <dwmw2@infradead.org>.
429 To compile this driver as a module, choose M here: the
430 module will be called applicom.
435 tristate "Sony Vaio Programmable I/O Control Device support"
436 depends on X86 && PCI && INPUT && !64BIT
438 This driver enables access to the Sony Programmable I/O Control
439 Device which can be found in many (all ?) Sony Vaio laptops.
441 If you have one of those laptops, read
442 <file:Documentation/laptops/sonypi.txt>, and say Y or M here.
444 To compile this driver as a module, choose M here: the
445 module will be called sonypi.
448 tristate "TANBAC TB0219 GPIO support"
449 depends on TANBAC_TB022X
452 source "drivers/char/pcmcia/Kconfig"
455 tristate "ACP Modem (Mwave) support"
456 depends on X86 && TTY
459 The ACP modem (Mwave) for Linux is a WinModem. It is composed of a
460 kernel driver and a user level application. Together these components
461 support direct attachment to public switched telephone networks (PSTNs)
462 and support selected world wide countries.
464 This version of the ACP Modem driver supports the IBM Thinkpad 600E,
465 600, and 770 that include on board ACP modem hardware.
467 The modem also supports the standard communications port interface
468 (ttySx) and is compatible with the Hayes AT Command Set.
470 The user level application needed to use this driver can be found at
471 the IBM Linux Technology Center (LTC) web site:
472 <http://www.ibm.com/linux/ltc/>.
474 If you own one of the above IBM Thinkpads which has the Mwave chipset
477 To compile this driver as a module, choose M here: the
478 module will be called mwave.
481 tristate "NatSemi SCx200 GPIO Support"
485 Give userspace access to the GPIO pins on the National
486 Semiconductor SCx200 processors.
488 If compiled as a module, it will be called scx200_gpio.
491 tristate "NatSemi PC8736x GPIO Support"
492 depends on X86_32 && !UML
493 default SCx200_GPIO # mostly N
494 select NSC_GPIO # needed for support routines
496 Give userspace access to the GPIO pins on the National
497 Semiconductor PC-8736x (x=[03456]) SuperIO chip. The chip
498 has multiple functional units, inc several managed by
499 hwmon/pc87360 driver. Tested with PC-87366
501 If compiled as a module, it will be called pc8736x_gpio.
504 tristate "NatSemi Base GPIO Support"
506 # selected by SCx200_GPIO and PC8736x_GPIO
507 # what about 2 selectors differing: m != y
509 Common support used (and needed) by scx200_gpio and
510 pc8736x_gpio drivers. If those drivers are built as
511 modules, this one will be too, named nsc_gpio
514 tristate "RAW driver (/dev/raw/rawN)"
517 The raw driver permits block devices to be bound to /dev/raw/rawN.
518 Once bound, I/O against /dev/raw/rawN uses efficient zero-copy I/O.
519 See the raw(8) manpage for more details.
521 Applications should preferably open the device (eg /dev/hda1)
522 with the O_DIRECT flag.
525 int "Maximum number of RAW devices to support (1-65536)"
526 depends on RAW_DRIVER
529 The maximum number of RAW devices that are supported.
530 Default is 256. Increase this number in case you need lots of
534 bool "HPET - High Precision Event Timer" if (X86 || IA64)
538 If you say Y here, you will have a miscdevice named "/dev/hpet/". Each
539 open selects one of the timers supported by the HPET. The timers are
540 non-periodic and/or periodic.
543 bool "Allow mmap of HPET"
547 If you say Y here, user applications will be able to mmap
550 In some hardware implementations, the page containing HPET
551 registers may also contain other things that shouldn't be
552 exposed to the user. If this applies to your hardware,
555 config HANGCHECK_TIMER
556 tristate "Hangcheck timer"
557 depends on X86 || IA64 || PPC64 || S390
559 The hangcheck-timer module detects when the system has gone
560 out to lunch past a certain margin. It can reboot the system
561 or merely print a warning.
564 tristate "MMTIMER Memory mapped RTC for SGI Altix"
565 depends on IA64_GENERIC || IA64_SGI_SN2
568 The mmtimer device allows direct userspace access to the
572 tristate "UV_MMTIMER Memory mapped RTC for SGI UV"
576 The uv_mmtimer device allows direct userspace access to the
579 source "drivers/char/tpm/Kconfig"
582 tristate "Telecom clock driver for ATCA SBC"
586 The telecom clock device is specific to the MPCBL0010 and MPCBL0050
587 ATCA computers and allows direct userspace access to the
588 configuration of the telecom clock configuration settings. This
589 device is used for hardware synchronization across the ATCA backplane
590 fabric. Upon loading, the driver exports a sysfs directory,
591 /sys/devices/platform/telco_clock, with a number of files for
592 controlling the behavior of this hardware.
597 depends on ISA || PCI
601 tristate "DCC tty driver"
604 source "drivers/s390/char/Kconfig"
607 bool "Enable device interface for some SMD packet ports"
611 Enables userspace clients to read and write to some packet SMD
612 ports via device interface for MSM chipset.
615 bool "Character-device access via hypervisor to the Tilera SPI ROM"
619 This device provides character-level read-write access
620 to the SROM, typically via the "0", "1", and "2" devices
621 in /dev/srom/. The Tilera hypervisor makes the flash
622 device appear much like a simple EEPROM, and knows
623 how to partition a single ROM for multiple purposes.