2# Character device configuration
5menu "Character devices"
7source "drivers/tty/Kconfig"
9config DEVMEM
10    bool "/dev/mem virtual device support"
11    default y
12    help
13      Say Y here if you want to support the /dev/mem device.
14      Some X server drivers access the video hardware using this device.
15      Accessing hardware directly from user space can be useful in some
16      cases, but it is not without risks.
17      When in doubt, say "N".
19config DEVKMEM
20    bool "/dev/kmem virtual device support"
21    default y
22    help
23      Say Y here if you want to support the /dev/kmem device. The
24      /dev/kmem device is rarely used, but can be used for certain
25      kind of kernel debugging operations.
26      When in doubt, say "N".
28config STALDRV
29    bool "Stallion multiport serial support"
30    depends on SERIAL_NONSTANDARD
31    help
32      Stallion cards give you many serial ports. You would need something
33      like this to connect more than two modems to your Linux box, for
34      instance in order to become a dial-in server. If you say Y here,
35      you will be asked for your specific card model in the next
36      questions. Make sure to read <file:Documentation/serial/stallion.txt>
37      in this case. If you have never heard about all this, it's safe to
38      say N.
40config SGI_SNSC
41    bool "SGI Altix system controller communication support"
42    depends on (IA64_SGI_SN2 || IA64_GENERIC)
43    help
44      If you have an SGI Altix and you want to enable system
45      controller communication from user space (you want this!),
46      say Y. Otherwise, say N.
48config SGI_TIOCX
49       bool "SGI TIO CX driver support"
50       depends on (IA64_SGI_SN2 || IA64_GENERIC)
51       help
52         If you have an SGI Altix and you have fpga devices attached
53         to your TIO, say Y here, otherwise say N.
55config SGI_MBCS
56       tristate "SGI FPGA Core Services driver support"
57       depends on SGI_TIOCX
58       help
59         If you have an SGI Altix with an attached SABrick
60         say Y or M here, otherwise say N.
62source "drivers/tty/serial/Kconfig"
64config TTY_PRINTK
65    bool "TTY driver to output user messages via printk"
66    depends on EXPERT && TTY
67    default n
68    ---help---
69      If you say Y here, the support for writing user messages (i.e.
70      console messages) via printk is available.
72      The feature is useful to inline user messages with kernel
73      messages.
74      In order to use this feature, you should output user messages
75      to /dev/ttyprintk or redirect console to this TTY.
77      If unsure, say N.
79config BFIN_OTP
80    tristate "Blackfin On-Chip OTP Memory Support"
81    depends on BLACKFIN && (BF51x || BF52x || BF54x)
82    default y
83    help
84      If you say Y here, you will get support for a character device
85      interface into the One Time Programmable memory pages that are
86      stored on the Blackfin processor. This will not get you access
87      to the secure memory pages however. You will need to write your
88      own secure code and reader for that.
90      To compile this driver as a module, choose M here: the module
91      will be called bfin-otp.
93      If unsure, it is safe to say Y.
96    bool "Enable writing support of OTP pages"
97    depends on BFIN_OTP
98    default n
99    help
100      If you say Y here, you will enable support for writing of the
101      OTP pages. This is dangerous by nature as you can only program
102      the pages once, so only enable this option when you actually
103      need it so as to not inadvertently clobber data.
105      If unsure, say N.
107config PRINTER
108    tristate "Parallel printer support"
109    depends on PARPORT
110    ---help---
111      If you intend to attach a printer to the parallel port of your Linux
112      box (as opposed to using a serial printer; if the connector at the
113      printer has 9 or 25 holes ["female"], then it's serial), say Y.
114      Also read the Printing-HOWTO, available from
115      <>.
117      It is possible to share one parallel port among several devices
118      (e.g. printer and ZIP drive) and it is safe to compile the
119      corresponding drivers into the kernel.
121      To compile this driver as a module, choose M here and read
122      <file:Documentation/parport.txt>. The module will be called lp.
124      If you have several parallel ports, you can specify which ports to
125      use with the "lp" kernel command line option. (Try "man bootparam"
126      or see the documentation of your boot loader (lilo or loadlin) about
127      how to pass options to the kernel at boot time.) The syntax of the
128      "lp" command line option can be found in <file:drivers/char/lp.c>.
130      If you have more than 8 printers, you need to increase the LP_NO
131      macro in lp.c and the PARPORT_MAX macro in parport.h.
133config LP_CONSOLE
134    bool "Support for console on line printer"
135    depends on PRINTER
136    ---help---
137      If you want kernel messages to be printed out as they occur, you
138      can have a console on the printer. This option adds support for
139      doing that; to actually get it to happen you need to pass the
140      option "console=lp0" to the kernel at boot time.
142      If the printer is out of paper (or off, or unplugged, or too
143      busy..) the kernel will stall until the printer is ready again.
144      By defining CONSOLE_LP_STRICT to 0 (at your own risk) you
145      can make the kernel continue when this happens,
146      but it'll lose the kernel messages.
148      If unsure, say N.
150config PPDEV
151    tristate "Support for user-space parallel port device drivers"
152    depends on PARPORT
153    ---help---
154      Saying Y to this adds support for /dev/parport device nodes. This
155      is needed for programs that want portable access to the parallel
156      port, for instance deviceid (which displays Plug-and-Play device
157      IDs).
159      This is the parallel port equivalent of SCSI generic support (sg).
160      It is safe to say N to this -- it is not needed for normal printing
161      or parallel port CD-ROM/disk support.
163      To compile this driver as a module, choose M here: the
164      module will be called ppdev.
166      If unsure, say N.
168source "drivers/tty/hvc/Kconfig"
171    tristate "Virtio console"
172    depends on VIRTIO && TTY
173    select HVC_DRIVER
174    help
175      Virtio console for use with lguest and other hypervisors.
177      Also serves as a general-purpose serial device for data
178      transfer between the guest and host. Character devices at
179      /dev/vportNpn will be created when corresponding ports are
180      found, where N is the device number and n is the port number
181      within that device. If specified by the host, a sysfs
182      attribute called 'name' will be populated with a name for
183      the port which can be used by udev scripts to create a
184      symlink to the device.
186config IBM_BSR
187    tristate "IBM POWER Barrier Synchronization Register support"
188    depends on PPC_PSERIES
189    help
190      This devices exposes a hardware mechanism for fast synchronization
191      of threads across a large system which avoids bouncing a cacheline
192      between several cores on a system
194source "drivers/char/ipmi/Kconfig"
196config DS1620
197    tristate "NetWinder thermometer support"
198    depends on ARCH_NETWINDER
199    help
200      Say Y here to include support for the thermal management hardware
201      found in the NetWinder. This driver allows the user to control the
202      temperature set points and to read the current temperature.
204      It is also possible to say M here to build it as a module (ds1620)
205      It is recommended to be used on a NetWinder, but it is not a
206      necessity.
208config NWBUTTON
209    tristate "NetWinder Button"
210    depends on ARCH_NETWINDER
211    ---help---
212      If you say Y here and create a character device node /dev/nwbutton
213      with major and minor numbers 10 and 158 ("man mknod"), then every
214      time the orange button is pressed a number of times, the number of
215      times the button was pressed will be written to that device.
217      This is most useful for applications, as yet unwritten, which
218      perform actions based on how many times the button is pressed in a
219      row.
221      Do not hold the button down for too long, as the driver does not
222      alter the behaviour of the hardware reset circuitry attached to the
223      button; it will still execute a hard reset if the button is held
224      down for longer than approximately five seconds.
226      To compile this driver as a module, choose M here: the
227      module will be called nwbutton.
229      Most people will answer Y to this question and "Reboot Using Button"
230      below to be able to initiate a system shutdown from the button.
233    bool "Reboot Using Button"
234    depends on NWBUTTON
235    help
236      If you say Y here, then you will be able to initiate a system
237      shutdown and reboot by pressing the orange button a number of times.
238      The number of presses to initiate the shutdown is two by default,
239      but this can be altered by modifying the value of NUM_PRESSES_REBOOT
240      in nwbutton.h and recompiling the driver or, if you compile the
241      driver as a module, you can specify the number of presses at load
242      time with "insmod button reboot_count=<something>".
244config NWFLASH
245    tristate "NetWinder flash support"
246    depends on ARCH_NETWINDER
247    ---help---
248      If you say Y here and create a character device /dev/flash with
249      major 10 and minor 160 you can manipulate the flash ROM containing
250      the NetWinder firmware. Be careful as accidentally overwriting the
251      flash contents can render your computer unbootable. On no account
252      allow random users access to this device. :-)
254      To compile this driver as a module, choose M here: the
255      module will be called nwflash.
257      If you're not sure, say N.
259source "drivers/char/hw_random/Kconfig"
261config NVRAM
262    tristate "/dev/nvram support"
263    depends on ATARI || X86 || (ARM && RTC_DRV_CMOS) || GENERIC_NVRAM
264    ---help---
265      If you say Y here and create a character special file /dev/nvram
266      with major number 10 and minor number 144 using mknod ("man mknod"),
267      you get read and write access to the extra bytes of non-volatile
268      memory in the real time clock (RTC), which is contained in every PC
269      and most Ataris. The actual number of bytes varies, depending on the
270      nvram in the system, but is usually 114 (128-14 for the RTC).
272      This memory is conventionally called "CMOS RAM" on PCs and "NVRAM"
273      on Ataris. /dev/nvram may be used to view settings there, or to
274      change them (with some utility). It could also be used to frequently
275      save a few bits of very important data that may not be lost over
276      power-off and for which writing to disk is too insecure. Note
277      however that most NVRAM space in a PC belongs to the BIOS and you
278      should NEVER idly tamper with it. See Ralf Brown's interrupt list
279      for a guide to the use of CMOS bytes by your BIOS.
281      On Atari machines, /dev/nvram is always configured and does not need
282      to be selected.
284      To compile this driver as a module, choose M here: the
285      module will be called nvram.
288# These legacy RTC drivers just cause too many conflicts with the generic
289# RTC framework ... let's not even try to coexist any more.
291if RTC_LIB=n
293config RTC
294    tristate "Enhanced Real Time Clock Support (legacy PC RTC driver)"
295    depends on !PPC && !PARISC && !IA64 && !M68K && !SPARC && !FRV \
296            && !ARM && !SUPERH && !S390 && !AVR32 && !BLACKFIN && !UML
297    ---help---
298      If you say Y here and create a character special file /dev/rtc with
299      major number 10 and minor number 135 using mknod ("man mknod"), you
300      will get access to the real time clock (or hardware clock) built
301      into your computer.
303      Every PC has such a clock built in. It can be used to generate
304      signals from as low as 1Hz up to 8192Hz, and can also be used
305      as a 24 hour alarm. It reports status information via the file
306      /proc/driver/rtc and its behaviour is set by various ioctls on
307      /dev/rtc.
309      If you run Linux on a multiprocessor machine and said Y to
310      "Symmetric Multi Processing" above, you should say Y here to read
311      and set the RTC in an SMP compatible fashion.
313      If you think you have a use for such a device (such as periodic data
314      sampling), then say Y here, and read <file:Documentation/rtc.txt>
315      for details.
317      To compile this driver as a module, choose M here: the
318      module will be called rtc.
320config JS_RTC
321    tristate "Enhanced Real Time Clock Support"
322    depends on SPARC32 && PCI
323    ---help---
324      If you say Y here and create a character special file /dev/rtc with
325      major number 10 and minor number 135 using mknod ("man mknod"), you
326      will get access to the real time clock (or hardware clock) built
327      into your computer.
329      Every PC has such a clock built in. It can be used to generate
330      signals from as low as 1Hz up to 8192Hz, and can also be used
331      as a 24 hour alarm. It reports status information via the file
332      /proc/driver/rtc and its behaviour is set by various ioctls on
333      /dev/rtc.
335      If you think you have a use for such a device (such as periodic data
336      sampling), then say Y here, and read <file:Documentation/rtc.txt>
337      for details.
339      To compile this driver as a module, choose M here: the
340      module will be called js-rtc.
342config GEN_RTC
343    tristate "Generic /dev/rtc emulation"
344    depends on RTC!=y && !IA64 && !ARM && !M32R && !MIPS && !SPARC && !FRV && !S390 && !SUPERH && !AVR32 && !BLACKFIN && !UML
345    ---help---
346      If you say Y here and create a character special file /dev/rtc with
347      major number 10 and minor number 135 using mknod ("man mknod"), you
348      will get access to the real time clock (or hardware clock) built
349      into your computer.
351      It reports status information via the file /proc/driver/rtc and its
352      behaviour is set by various ioctls on /dev/rtc. If you enable the
353      "extended RTC operation" below it will also provide an emulation
354      for RTC_UIE which is required by some programs and may improve
355      precision in some cases.
357      To compile this driver as a module, choose M here: the
358      module will be called genrtc.
360config GEN_RTC_X
361    bool "Extended RTC operation"
362    depends on GEN_RTC
363    help
364      Provides an emulation for RTC_UIE which is required by some programs
365      and may improve precision of the generic RTC support in some cases.
367config EFI_RTC
368    bool "EFI Real Time Clock Services"
369    depends on IA64
371config DS1302
372    tristate "DS1302 RTC support"
373    depends on M32R && (PLAT_M32700UT || PLAT_OPSPUT)
374    help
375      If you say Y here and create a character special file /dev/rtc with
376      major number 121 and minor number 0 using mknod ("man mknod"), you
377      will get access to the real time clock (or hardware clock) built
378      into your computer.
380endif # RTC_LIB
382config DTLK
383    tristate "Double Talk PC internal speech card support"
384    depends on ISA
385    help
386      This driver is for the DoubleTalk PC, a speech synthesizer
387      manufactured by RC Systems (<>). It is also
388      called the `internal DoubleTalk'.
390      To compile this driver as a module, choose M here: the
391      module will be called dtlk.
394    tristate "Xilinx HWICAP Support"
395    depends on XILINX_VIRTEX || MICROBLAZE
396    help
397      This option enables support for Xilinx Internal Configuration
398      Access Port (ICAP) driver. The ICAP is used on Xilinx Virtex
399      FPGA platforms to partially reconfigure the FPGA at runtime.
401      If unsure, say N.
403config R3964
404    tristate "Siemens R3964 line discipline"
405    depends on TTY
406    ---help---
407      This driver allows synchronous communication with devices using the
408      Siemens R3964 packet protocol. Unless you are dealing with special
409      hardware like PLCs, you are unlikely to need this.
411      To compile this driver as a module, choose M here: the
412      module will be called n_r3964.
414      If unsure, say N.
416config APPLICOM
417    tristate "Applicom intelligent fieldbus card support"
418    depends on PCI
419    ---help---
420      This driver provides the kernel-side support for the intelligent
421      fieldbus cards made by Applicom International. More information
422      about these cards can be found on the WWW at the address
423      <>, or by email from David Woodhouse
424      <>.
426      To compile this driver as a module, choose M here: the
427      module will be called applicom.
429      If unsure, say N.
431config SONYPI
432    tristate "Sony Vaio Programmable I/O Control Device support"
433    depends on X86 && PCI && INPUT && !64BIT
434    ---help---
435      This driver enables access to the Sony Programmable I/O Control
436      Device which can be found in many (all ?) Sony Vaio laptops.
438      If you have one of those laptops, read
439      <file:Documentation/laptops/sonypi.txt>, and say Y or M here.
441      To compile this driver as a module, choose M here: the
442      module will be called sonypi.
444config GPIO_TB0219
445    tristate "TANBAC TB0219 GPIO support"
446    depends on TANBAC_TB022X
447    select GPIO_VR41XX
449source "drivers/char/pcmcia/Kconfig"
451config MWAVE
452    tristate "ACP Modem (Mwave) support"
453    depends on X86 && TTY
454    select SERIAL_8250
455    ---help---
456      The ACP modem (Mwave) for Linux is a WinModem. It is composed of a
457      kernel driver and a user level application. Together these components
458      support direct attachment to public switched telephone networks (PSTNs)
459      and support selected world wide countries.
461      This version of the ACP Modem driver supports the IBM Thinkpad 600E,
462      600, and 770 that include on board ACP modem hardware.
464      The modem also supports the standard communications port interface
465      (ttySx) and is compatible with the Hayes AT Command Set.
467      The user level application needed to use this driver can be found at
468      the IBM Linux Technology Center (LTC) web site:
469      <>.
471      If you own one of the above IBM Thinkpads which has the Mwave chipset
472      in it, say Y.
474      To compile this driver as a module, choose M here: the
475      module will be called mwave.
477config SCx200_GPIO
478    tristate "NatSemi SCx200 GPIO Support"
479    depends on SCx200
480    select NSC_GPIO
481    help
482      Give userspace access to the GPIO pins on the National
483      Semiconductor SCx200 processors.
485      If compiled as a module, it will be called scx200_gpio.
487config PC8736x_GPIO
488    tristate "NatSemi PC8736x GPIO Support"
489    depends on X86_32 && !UML
490    default SCx200_GPIO # mostly N
491    select NSC_GPIO # needed for support routines
492    help
493      Give userspace access to the GPIO pins on the National
494      Semiconductor PC-8736x (x=[03456]) SuperIO chip. The chip
495      has multiple functional units, inc several managed by
496      hwmon/pc87360 driver. Tested with PC-87366
498      If compiled as a module, it will be called pc8736x_gpio.
500config NSC_GPIO
501    tristate "NatSemi Base GPIO Support"
502    depends on X86_32
503    # selected by SCx200_GPIO and PC8736x_GPIO
504    # what about 2 selectors differing: m != y
505    help
506      Common support used (and needed) by scx200_gpio and
507      pc8736x_gpio drivers. If those drivers are built as
508      modules, this one will be too, named nsc_gpio
510config RAW_DRIVER
511    tristate "RAW driver (/dev/raw/rawN)"
512    depends on BLOCK
513    help
514      The raw driver permits block devices to be bound to /dev/raw/rawN.
515      Once bound, I/O against /dev/raw/rawN uses efficient zero-copy I/O.
516      See the raw(8) manpage for more details.
518          Applications should preferably open the device (eg /dev/hda1)
519          with the O_DIRECT flag.
521config MAX_RAW_DEVS
522    int "Maximum number of RAW devices to support (1-65536)"
523    depends on RAW_DRIVER
524    default "256"
525    help
526      The maximum number of RAW devices that are supported.
527      Default is 256. Increase this number in case you need lots of
528      raw devices.
530config HPET
531    bool "HPET - High Precision Event Timer" if (X86 || IA64)
532    default n
533    depends on ACPI
534    help
535      If you say Y here, you will have a miscdevice named "/dev/hpet/". Each
536      open selects one of the timers supported by the HPET. The timers are
537      non-periodic and/or periodic.
539config HPET_MMAP
540    bool "Allow mmap of HPET"
541    default y
542    depends on HPET
543    help
544      If you say Y here, user applications will be able to mmap
545      the HPET registers.
547      In some hardware implementations, the page containing HPET
548      registers may also contain other things that shouldn't be
549      exposed to the user. If this applies to your hardware,
550      say N here.
553    tristate "Hangcheck timer"
554    depends on X86 || IA64 || PPC64 || S390
555    help
556      The hangcheck-timer module detects when the system has gone
557      out to lunch past a certain margin. It can reboot the system
558      or merely print a warning.
560config MMTIMER
561    tristate "MMTIMER Memory mapped RTC for SGI Altix"
562    depends on IA64_GENERIC || IA64_SGI_SN2
563    default y
564    help
565      The mmtimer device allows direct userspace access to the
566      Altix system timer.
568config UV_MMTIMER
569    tristate "UV_MMTIMER Memory mapped RTC for SGI UV"
570    depends on X86_UV
571    default m
572    help
573      The uv_mmtimer device allows direct userspace access to the
574      UV system timer.
576source "drivers/char/tpm/Kconfig"
578config TELCLOCK
579    tristate "Telecom clock driver for ATCA SBC"
580    depends on X86
581    default n
582    help
583      The telecom clock device is specific to the MPCBL0010 and MPCBL0050
584      ATCA computers and allows direct userspace access to the
585      configuration of the telecom clock configuration settings. This
586      device is used for hardware synchronization across the ATCA backplane
587      fabric. Upon loading, the driver exports a sysfs directory,
588      /sys/devices/platform/telco_clock, with a number of files for
589      controlling the behavior of this hardware.
591config DEVPORT
592    bool
593    depends on !M68K
594    depends on ISA || PCI
595    default y
597source "drivers/s390/char/Kconfig"
599config MSM_SMD_PKT
600    bool "Enable device interface for some SMD packet ports"
601    default n
602    depends on MSM_SMD
603    help
604      Enables userspace clients to read and write to some packet SMD
605      ports via device interface for MSM chipset.
607config TILE_SROM
608    bool "Character-device access via hypervisor to the Tilera SPI ROM"
609    depends on TILE
610    default y
611    ---help---
612      This device provides character-level read-write access
613      to the SROM, typically via the "0", "1", and "2" devices
614      in /dev/srom/. The Tilera hypervisor makes the flash
615      device appear much like a simple EEPROM, and knows
616      how to partition a single ROM for multiple purposes.

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