xref: /openbmc/linux/drivers/tty/serial/8250/Kconfig (revision 4562236b)
1#
2# The 8250/16550 serial drivers.  You shouldn't be in this list unless
3# you somehow have an implicit or explicit dependency on SERIAL_8250.
4#
5
6config SERIAL_8250
7	tristate "8250/16550 and compatible serial support"
8	select SERIAL_CORE
9	---help---
10	  This selects whether you want to include the driver for the standard
11	  serial ports.  The standard answer is Y.  People who might say N
12	  here are those that are setting up dedicated Ethernet WWW/FTP
13	  servers, or users that have one of the various bus mice instead of a
14	  serial mouse and don't intend to use their machine's standard serial
15	  port for anything.  (Note that the Cyclades multi serial port driver
16	  does not need this driver built in for it to work.)
17
18	  To compile this driver as a module, choose M here: the
19	  module will be called 8250.
20	  [WARNING: Do not compile this driver as a module if you are using
21	  non-standard serial ports, since the configuration information will
22	  be lost when the driver is unloaded.  This limitation may be lifted
23	  in the future.]
24
25	  BTW1: If you have a mouseman serial mouse which is not recognized by
26	  the X window system, try running gpm first.
27
28	  BTW2: If you intend to use a software modem (also called Winmodem)
29	  under Linux, forget it.  These modems are crippled and require
30	  proprietary drivers which are only available under Windows.
31
32	  Most people will say Y or M here, so that they can use serial mice,
33	  modems and similar devices connecting to the standard serial ports.
34
35config SERIAL_8250_DEPRECATED_OPTIONS
36	bool "Support 8250_core.* kernel options (DEPRECATED)"
37	depends on SERIAL_8250
38	default y
39	---help---
40	  In 3.7 we renamed 8250 to 8250_core by mistake, so now we have to
41	  accept kernel parameters in both forms like 8250_core.nr_uarts=4 and
42	  8250.nr_uarts=4. We now renamed the module back to 8250, but if
43	  anybody noticed in 3.7 and changed their userspace we still have to
44	  keep the 8250_core.* options around until they revert the changes
45	  they already did.
46
47	  If 8250 is built as a module, this adds 8250_core alias instead.
48
49	  If you did not notice yet and/or you have userspace from pre-3.7, it
50	  is safe (and recommended) to say N here.
51
52config SERIAL_8250_PNP
53	bool "8250/16550 PNP device support" if EXPERT
54	depends on SERIAL_8250 && PNP
55	default y
56	---help---
57	  This builds standard PNP serial support. You may be able to
58	  disable this feature if you only need legacy serial support.
59
60config SERIAL_8250_FINTEK
61	bool "Support for Fintek F81216A LPC to 4 UART RS485 API"
62	depends on SERIAL_8250
63	---help---
64	  Selecting this option will add support for the RS485 capabilities
65	  of the Fintek F81216A LPC to 4 UART.
66
67	  If this option is not selected the device will be configured as a
68	  standard 16550A serial port.
69
70	  If unsure, say N.
71
72config SERIAL_8250_CONSOLE
73	bool "Console on 8250/16550 and compatible serial port"
74	depends on SERIAL_8250=y
75	select SERIAL_CORE_CONSOLE
76	select SERIAL_EARLYCON
77	---help---
78	  If you say Y here, it will be possible to use a serial port as the
79	  system console (the system console is the device which receives all
80	  kernel messages and warnings and which allows logins in single user
81	  mode). This could be useful if some terminal or printer is connected
82	  to that serial port.
83
84	  Even if you say Y here, the currently visible virtual console
85	  (/dev/tty0) will still be used as the system console by default, but
86	  you can alter that using a kernel command line option such as
87	  "console=ttyS1". (Try "man bootparam" or see the documentation of
88	  your boot loader (grub or lilo or loadlin) about how to pass options
89	  to the kernel at boot time.)
90
91	  If you don't have a VGA card installed and you say Y here, the
92	  kernel will automatically use the first serial line, /dev/ttyS0, as
93	  system console.
94
95	  You can set that using a kernel command line option such as
96	  "console=uart8250,io,0x3f8,9600n8"
97	  "console=uart8250,mmio,0xff5e0000,115200n8".
98	  and it will switch to normal serial console when the corresponding
99	  port is ready.
100	  "earlycon=uart8250,io,0x3f8,9600n8"
101	  "earlycon=uart8250,mmio,0xff5e0000,115200n8".
102	  it will not only setup early console.
103
104	  If unsure, say N.
105
106config SERIAL_8250_GSC
107	tristate
108	depends on SERIAL_8250 && GSC
109	default SERIAL_8250
110
111config SERIAL_8250_DMA
112	bool "DMA support for 16550 compatible UART controllers" if EXPERT
113	depends on SERIAL_8250 && DMADEVICES=y
114	default SERIAL_8250
115	help
116	  This builds DMA support that can be used with 8250/16650
117	  compatible UART controllers that support DMA signaling.
118
119config SERIAL_8250_PCI
120	tristate "8250/16550 PCI device support"
121	depends on SERIAL_8250 && PCI
122	default SERIAL_8250
123	help
124	  This builds standard PCI serial support. You may be able to
125	  disable this feature if you only need legacy serial support.
126	  Saves about 9K.
127	  Note that serial ports on NetMos 9835 Multi-I/O cards are handled
128	  by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL.
129
130config SERIAL_8250_EXAR
131	tristate "8250/16550 Exar/Commtech PCI/PCIe device support"
132	depends on SERIAL_8250_PCI
133	default SERIAL_8250
134	help
135	  This builds support for XR17C1xx, XR17V3xx and some Commtech
136	  422x PCIe serial cards that are not covered by the more generic
137	  SERIAL_8250_PCI option.
138
139config SERIAL_8250_HP300
140	tristate
141	depends on SERIAL_8250 && HP300
142	default SERIAL_8250
143
144config SERIAL_8250_CS
145	tristate "8250/16550 PCMCIA device support"
146	depends on PCMCIA && SERIAL_8250
147	---help---
148	  Say Y here to enable support for 16-bit PCMCIA serial devices,
149	  including serial port cards, modems, and the modem functions of
150	  multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
151	  credit-card size devices often used with laptops.)
152
153	  To compile this driver as a module, choose M here: the
154	  module will be called serial_cs.
155
156	  If unsure, say N.
157
158config SERIAL_8250_NR_UARTS
159	int "Maximum number of 8250/16550 serial ports"
160	depends on SERIAL_8250
161	default "4"
162	help
163	  Set this to the number of serial ports you want the driver
164	  to support.  This includes any ports discovered via ACPI or
165	  PCI enumeration and any ports that may be added at run-time
166	  via hot-plug, or any ISA multi-port serial cards.
167
168config SERIAL_8250_RUNTIME_UARTS
169	int "Number of 8250/16550 serial ports to register at runtime"
170	depends on SERIAL_8250
171	range 0 SERIAL_8250_NR_UARTS
172	default "4"
173	help
174	  Set this to the maximum number of serial ports you want
175	  the kernel to register at boot time.  This can be overridden
176	  with the module parameter "nr_uarts", or boot-time parameter
177	  8250.nr_uarts
178
179config SERIAL_8250_EXTENDED
180	bool "Extended 8250/16550 serial driver options"
181	depends on SERIAL_8250
182	help
183	  If you wish to use any non-standard features of the standard "dumb"
184	  driver, say Y here. This includes HUB6 support, shared serial
185	  interrupts, special multiport support, support for more than the
186	  four COM 1/2/3/4 boards, etc.
187
188	  Note that the answer to this question won't directly affect the
189	  kernel: saying N will just cause the configurator to skip all
190	  the questions about serial driver options. If unsure, say N.
191
192config SERIAL_8250_MANY_PORTS
193	bool "Support more than 4 legacy serial ports"
194	depends on SERIAL_8250_EXTENDED && !IA64
195	help
196	  Say Y here if you have dumb serial boards other than the four
197	  standard COM 1/2/3/4 ports. This may happen if you have an AST
198	  FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
199	  from <http://www.tldp.org/docs.html#howto>), or other custom
200	  serial port hardware which acts similar to standard serial port
201	  hardware. If you only use the standard COM 1/2/3/4 ports, you can
202	  say N here to save some memory. You can also say Y if you have an
203	  "intelligent" multiport card such as Cyclades, Digiboards, etc.
204
205#
206# Multi-port serial cards
207#
208
209config SERIAL_8250_FOURPORT
210	tristate "Support Fourport cards"
211	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
212	help
213	  Say Y here if you have an AST FourPort serial board.
214
215	  To compile this driver as a module, choose M here: the module
216	  will be called 8250_fourport.
217
218config SERIAL_8250_ACCENT
219	tristate "Support Accent cards"
220	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
221	help
222	  Say Y here if you have an Accent Async serial board.
223
224	  To compile this driver as a module, choose M here: the module
225	  will be called 8250_accent.
226
227config SERIAL_8250_ASPEED_VUART
228	tristate "Aspeed Virtual UART"
229	depends on SERIAL_8250
230	depends on OF
231	help
232	  If you want to use the virtual UART (VUART) device on Aspeed
233	  BMC platforms, enable this option. This enables the 16550A-
234	  compatible device on the local LPC bus, giving a UART device
235	  with no physical RS232 connections.
236
237config SERIAL_8250_BOCA
238	tristate "Support Boca cards"
239	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
240	help
241	  Say Y here if you have a Boca serial board.  Please read the Boca
242	  mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
243
244	  To compile this driver as a module, choose M here: the module
245	  will be called 8250_boca.
246
247config SERIAL_8250_EXAR_ST16C554
248	tristate "Support Exar ST16C554/554D Quad UART"
249	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
250	help
251	  The Uplogix Envoy TU301 uses this Exar Quad UART.  If you are
252	  tinkering with your Envoy TU301, or have a machine with this UART,
253	  say Y here.
254
255	  To compile this driver as a module, choose M here: the module
256	  will be called 8250_exar_st16c554.
257
258config SERIAL_8250_HUB6
259	tristate "Support Hub6 cards"
260	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
261	help
262	  Say Y here if you have a HUB6 serial board.
263
264	  To compile this driver as a module, choose M here: the module
265	  will be called 8250_hub6.
266
267#
268# Misc. options/drivers.
269#
270
271config SERIAL_8250_SHARE_IRQ
272	bool "Support for sharing serial interrupts"
273	depends on SERIAL_8250_EXTENDED
274	help
275	  Some serial boards have hardware support which allows multiple dumb
276	  serial ports on the same board to share a single IRQ. To enable
277	  support for this in the serial driver, say Y here.
278
279config SERIAL_8250_DETECT_IRQ
280	bool "Autodetect IRQ on standard ports (unsafe)"
281	depends on SERIAL_8250_EXTENDED
282	help
283	  Say Y here if you want the kernel to try to guess which IRQ
284	  to use for your serial port.
285
286	  This is considered unsafe; it is far better to configure the IRQ in
287	  a boot script using the setserial command.
288
289	  If unsure, say N.
290
291config SERIAL_8250_RSA
292	bool "Support RSA serial ports"
293	depends on SERIAL_8250_EXTENDED
294	help
295	  Say Y here if you have a IODATA RSA-DV II/S ISA card and
296	  would like to use its >115kbps speeds.
297	  You will need to provide module parameter "probe_rsa", or boot-time
298	  parameter 8250.probe_rsa with I/O addresses of this card then.
299
300	  If you don't have such card, or if unsure, say N.
301
302config SERIAL_8250_ACORN
303	tristate "Acorn expansion card serial port support"
304	depends on ARCH_ACORN && SERIAL_8250
305	help
306	  If you have an Atomwide Serial card or Serial Port card for an Acorn
307	  system, say Y to this option.  The driver can handle 1, 2, or 3 port
308	  cards.  If unsure, say N.
309
310config SERIAL_8250_BCM2835AUX
311	tristate "BCM2835 auxiliar mini UART support"
312	depends on ARCH_BCM2835 || COMPILE_TEST
313	depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
314	help
315	  Support for the BCM2835 auxiliar mini UART.
316
317	  Features and limitations of the UART are
318	    Registers are similar to 16650 registers,
319              set bits in the control registers that are unsupported
320	      are ignored and read back as 0
321	    7/8 bit operation with 1 start and 1 stop bit
322	    8 symbols deep fifo for rx and tx
323	    SW controlled RTS and SW readable CTS
324	    Clock rate derived from system clock
325	    Uses 8 times oversampling (compared to 16 times for 16650)
326	    Missing break detection (but break generation)
327	    Missing framing error detection
328	    Missing parity bit
329	    Missing receive time-out interrupt
330	    Missing DCD, DSR, DTR and RI signals
331
332	  If unsure, say N.
333
334config SERIAL_8250_FSL
335	bool
336	depends on SERIAL_8250_CONSOLE
337	default PPC || ARM || ARM64
338
339config SERIAL_8250_DW
340	tristate "Support for Synopsys DesignWare 8250 quirks"
341	depends on SERIAL_8250
342	help
343	  Selecting this option will enable handling of the extra features
344	  present in the Synopsys DesignWare APB UART.
345
346config SERIAL_8250_EM
347	tristate "Support for Emma Mobile integrated serial port"
348	depends on SERIAL_8250 && ARM && HAVE_CLK
349	help
350	  Selecting this option will add support for the integrated serial
351	  port hardware found on the Emma Mobile line of processors.
352	  If unsure, say N.
353
354config SERIAL_8250_RT288X
355	bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
356	depends on SERIAL_8250
357	default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
358	help
359	  Selecting this option will add support for the alternate register
360	  layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
361	  If unsure, say N.
362
363config SERIAL_8250_OMAP
364	tristate "Support for OMAP internal UART (8250 based driver)"
365	depends on SERIAL_8250 && ARCH_OMAP2PLUS
366	help
367	  If you have a machine based on an Texas Instruments OMAP CPU you
368	  can enable its onboard serial ports by enabling this option.
369
370	  This driver uses ttyS instead of ttyO.
371
372config SERIAL_8250_OMAP_TTYO_FIXUP
373	bool "Replace ttyO with ttyS"
374	depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
375	default y
376	help
377	  This option replaces the "console=ttyO" argument with the matching
378	  ttyS argument if the user did not specified it on the command line.
379	  This ensures that the user can see the kernel output during boot
380	  which he wouldn't see otherwise. The getty has still to be configured
381	  for ttyS instead of ttyO regardless of this option.
382	  This option is intended for people who "automatically" enable this
383	  driver without knowing that this driver requires a different console=
384	  argument. If you read this, please keep this option disabled and
385	  instead update your kernel command line. If you prepare a kernel for a
386	  distribution or other kind of larger user base then you probably want
387	  to keep this option enabled. Otherwise people might complain about a
388	  not booting kernel because the serial console remains silent in case
389	  they forgot to update the command line.
390
391config SERIAL_8250_LPC18XX
392	tristate "NXP LPC18xx/43xx serial port support"
393	depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
394	default ARCH_LPC18XX
395	help
396	  If you have a LPC18xx/43xx based board and want to use the
397	  serial port, say Y to this option. If unsure, say Y.
398
399config SERIAL_8250_MT6577
400	tristate "Mediatek serial port support"
401	depends on SERIAL_8250 && ARCH_MEDIATEK
402	help
403	  If you have a Mediatek based board and want to use the
404	  serial port, say Y to this option. If unsure, say N.
405
406config SERIAL_8250_UNIPHIER
407	tristate "Support for UniPhier on-chip UART"
408	depends on SERIAL_8250
409	depends on ARCH_UNIPHIER || COMPILE_TEST
410	help
411	  If you have a UniPhier based board and want to use the on-chip
412	  serial ports, say Y to this option. If unsure, say N.
413
414config SERIAL_8250_INGENIC
415	tristate "Support for Ingenic SoC serial ports"
416	depends on SERIAL_8250
417	depends on OF_FLATTREE
418	depends on MIPS || COMPILE_TEST
419	help
420	  If you have a system using an Ingenic SoC and wish to make use of
421	  its UARTs, say Y to this option. If unsure, say N.
422
423config SERIAL_8250_LPSS
424	tristate "Support for serial ports on Intel LPSS platforms"
425	default SERIAL_8250
426	depends on SERIAL_8250 && PCI
427	depends on X86 || COMPILE_TEST
428	select DW_DMAC_CORE if SERIAL_8250_DMA
429	select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
430	select RATIONAL
431	help
432	  Selecting this option will enable handling of the extra features
433	  present on the UART found on various Intel platforms such as:
434	    - Intel Baytrail SoC
435	    - Intel Braswell SoC
436	    - Intel Quark X1000 SoC
437
438config SERIAL_8250_MID
439	tristate "Support for serial ports on Intel MID platforms"
440	default SERIAL_8250
441	depends on SERIAL_8250 && PCI
442	depends on X86 || COMPILE_TEST
443	select HSU_DMA if SERIAL_8250_DMA
444	select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
445	select RATIONAL
446	help
447	  Selecting this option will enable handling of the extra features
448	  present on the UART found on Intel Medfield SOC and various other
449	  Intel platforms.
450
451config SERIAL_8250_MOXA
452	tristate "MOXA SmartIO MUE support"
453	depends on SERIAL_8250 && PCI
454	help
455	  Say Y here if you have a Moxa SmartIO MUE multiport serial card.
456	  If unsure, say N.
457
458	  This driver can also be built as a module. The module will be called
459	  8250_moxa. If you want to do that, say M here.
460
461config SERIAL_8250_PXA
462	tristate "PXA serial port support"
463	depends on SERIAL_8250
464	depends on ARCH_PXA || ARCH_MMP
465	help
466	  If you have a machine based on an Intel XScale PXA2xx CPU you can
467	  enable its onboard serial ports by enabling this option. The option is
468	  applicable to both devicetree and legacy boards, and early console is
469	  part of its support.
470
471config SERIAL_OF_PLATFORM
472	tristate "Devicetree based probing for 8250 ports"
473	depends on SERIAL_8250 && OF
474	help
475	  This option is used for all 8250 compatible serial ports that
476	  are probed through devicetree, including Open Firmware based
477	  PowerPC systems and embedded systems on architectures using the
478	  flattened device tree format.
479