xref: /openbmc/linux/drivers/char/Kconfig (revision 7be022c9)
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	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
61config 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
78config 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
96config 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
113config 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
121config 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
135source "drivers/char/ipmi/Kconfig"
136
137config 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
149config 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
173config 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
185config 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
200source "drivers/char/hw_random/Kconfig"
201
202config 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
213config 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
223config 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
238config 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
251config 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
277config 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
287config 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
300config 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
310config 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
319config DEVMEM_BOOTPARAM
320	bool "mem.devmem boot parameter"
321	depends on DEVMEM
322	default n
323	help
324	  This option adds a 'mem.devmem' kernel parameter which activates
325	  the /dev/mem device when enabled.
326	  When in doubt, say "N".
327
328config NVRAM
329	tristate "/dev/nvram support"
330	depends on X86 || HAVE_ARCH_NVRAM_OPS
331	default M68K || PPC
332	help
333	  If you say Y here and create a character special file /dev/nvram
334	  with major number 10 and minor number 144 using mknod ("man mknod"),
335	  you get read and write access to the non-volatile memory.
336
337	  /dev/nvram may be used to view settings in NVRAM or to change them
338	  (with some utility). It could also be used to frequently
339	  save a few bits of very important data that may not be lost over
340	  power-off and for which writing to disk is too insecure. Note
341	  however that most NVRAM space in a PC belongs to the BIOS and you
342	  should NEVER idly tamper with it. See Ralf Brown's interrupt list
343	  for a guide to the use of CMOS bytes by your BIOS.
344
345	  This memory is conventionally called "NVRAM" on PowerPC machines,
346	  "CMOS RAM" on PCs, "NVRAM" on Ataris and "PRAM" on Macintoshes.
347
348	  To compile this driver as a module, choose M here: the
349	  module will be called nvram.
350
351config DEVPORT
352	bool "/dev/port character device"
353	depends on HAS_IOPORT
354	default y
355	help
356	  Say Y here if you want to support the /dev/port device. The /dev/port
357	  device is similar to /dev/mem, but for I/O ports.
358
359config HPET
360	bool "HPET - High Precision Event Timer" if (X86 || IA64)
361	default n
362	depends on ACPI
363	help
364	  If you say Y here, you will have a miscdevice named "/dev/hpet/".  Each
365	  open selects one of the timers supported by the HPET.  The timers are
366	  non-periodic and/or periodic.
367
368config HPET_MMAP
369	bool "Allow mmap of HPET"
370	default y
371	depends on HPET
372	help
373	  If you say Y here, user applications will be able to mmap
374	  the HPET registers.
375
376config HPET_MMAP_DEFAULT
377	bool "Enable HPET MMAP access by default"
378	default y
379	depends on HPET_MMAP
380	help
381	  In some hardware implementations, the page containing HPET
382	  registers may also contain other things that shouldn't be
383	  exposed to the user.  This option selects the default (if
384	  kernel parameter hpet_mmap is not set) user access to the
385	  registers for applications that require it.
386
387config HANGCHECK_TIMER
388	tristate "Hangcheck timer"
389	depends on X86 || IA64 || PPC64 || S390
390	help
391	  The hangcheck-timer module detects when the system has gone
392	  out to lunch past a certain margin.  It can reboot the system
393	  or merely print a warning.
394
395config UV_MMTIMER
396	tristate "UV_MMTIMER Memory mapped RTC for SGI UV"
397	depends on X86_UV
398	default m
399	help
400	  The uv_mmtimer device allows direct userspace access to the
401	  UV system timer.
402
403source "drivers/char/tpm/Kconfig"
404
405config TELCLOCK
406	tristate "Telecom clock driver for ATCA SBC"
407	depends on X86
408	default n
409	help
410	  The telecom clock device is specific to the MPCBL0010 and MPCBL0050
411	  ATCA computers and allows direct userspace access to the
412	  configuration of the telecom clock configuration settings.  This
413	  device is used for hardware synchronization across the ATCA backplane
414	  fabric.  Upon loading, the driver exports a sysfs directory,
415	  /sys/devices/platform/telco_clock, with a number of files for
416	  controlling the behavior of this hardware.
417
418source "drivers/s390/char/Kconfig"
419
420source "drivers/char/xillybus/Kconfig"
421
422config ADI
423	tristate "SPARC Privileged ADI driver"
424	depends on SPARC64
425	default m
426	help
427	  SPARC M7 and newer processors utilize ADI (Application Data
428	  Integrity) to version and protect memory.  This driver provides
429	  read/write access to the ADI versions for privileged processes.
430	  This feature is also known as MCD (Memory Corruption Detection)
431	  and SSM (Silicon Secured Memory).  Intended consumers of this
432	  driver include crash and makedumpfile.
433
434endmenu
435