xref: /openbmc/linux/drivers/tty/serial/8250/Kconfig (revision c0c74acb)
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_BOCA
228	tristate "Support Boca cards"
229	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
230	help
231	  Say Y here if you have a Boca serial board.  Please read the Boca
232	  mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
233
234	  To compile this driver as a module, choose M here: the module
235	  will be called 8250_boca.
236
237config SERIAL_8250_EXAR_ST16C554
238	tristate "Support Exar ST16C554/554D Quad UART"
239	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
240	help
241	  The Uplogix Envoy TU301 uses this Exar Quad UART.  If you are
242	  tinkering with your Envoy TU301, or have a machine with this UART,
243	  say Y here.
244
245	  To compile this driver as a module, choose M here: the module
246	  will be called 8250_exar_st16c554.
247
248config SERIAL_8250_HUB6
249	tristate "Support Hub6 cards"
250	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
251	help
252	  Say Y here if you have a HUB6 serial board.
253
254	  To compile this driver as a module, choose M here: the module
255	  will be called 8250_hub6.
256
257#
258# Misc. options/drivers.
259#
260
261config SERIAL_8250_SHARE_IRQ
262	bool "Support for sharing serial interrupts"
263	depends on SERIAL_8250_EXTENDED
264	help
265	  Some serial boards have hardware support which allows multiple dumb
266	  serial ports on the same board to share a single IRQ. To enable
267	  support for this in the serial driver, say Y here.
268
269config SERIAL_8250_DETECT_IRQ
270	bool "Autodetect IRQ on standard ports (unsafe)"
271	depends on SERIAL_8250_EXTENDED
272	help
273	  Say Y here if you want the kernel to try to guess which IRQ
274	  to use for your serial port.
275
276	  This is considered unsafe; it is far better to configure the IRQ in
277	  a boot script using the setserial command.
278
279	  If unsure, say N.
280
281config SERIAL_8250_RSA
282	bool "Support RSA serial ports"
283	depends on SERIAL_8250_EXTENDED
284	help
285	  Say Y here if you have a IODATA RSA-DV II/S ISA card and
286	  would like to use its >115kbps speeds.
287	  You will need to provide module parameter "probe_rsa", or boot-time
288	  parameter 8250.probe_rsa with I/O addresses of this card then.
289
290	  If you don't have such card, or if unsure, say N.
291
292config SERIAL_8250_ACORN
293	tristate "Acorn expansion card serial port support"
294	depends on ARCH_ACORN && SERIAL_8250
295	help
296	  If you have an Atomwide Serial card or Serial Port card for an Acorn
297	  system, say Y to this option.  The driver can handle 1, 2, or 3 port
298	  cards.  If unsure, say N.
299
300config SERIAL_8250_BCM2835AUX
301	tristate "BCM2835 auxiliar mini UART support"
302	depends on ARCH_BCM2835 || COMPILE_TEST
303	depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
304	help
305	  Support for the BCM2835 auxiliar mini UART.
306
307	  Features and limitations of the UART are
308	    Registers are similar to 16650 registers,
309              set bits in the control registers that are unsupported
310	      are ignored and read back as 0
311	    7/8 bit operation with 1 start and 1 stop bit
312	    8 symbols deep fifo for rx and tx
313	    SW controlled RTS and SW readable CTS
314	    Clock rate derived from system clock
315	    Uses 8 times oversampling (compared to 16 times for 16650)
316	    Missing break detection (but break generation)
317	    Missing framing error detection
318	    Missing parity bit
319	    Missing receive time-out interrupt
320	    Missing DCD, DSR, DTR and RI signals
321
322	  If unsure, say N.
323
324config SERIAL_8250_FSL
325	bool
326	depends on SERIAL_8250_CONSOLE
327	default PPC || ARM || ARM64
328
329config SERIAL_8250_DW
330	tristate "Support for Synopsys DesignWare 8250 quirks"
331	depends on SERIAL_8250
332	help
333	  Selecting this option will enable handling of the extra features
334	  present in the Synopsys DesignWare APB UART.
335
336config SERIAL_8250_EM
337	tristate "Support for Emma Mobile integrated serial port"
338	depends on SERIAL_8250 && ARM && HAVE_CLK
339	help
340	  Selecting this option will add support for the integrated serial
341	  port hardware found on the Emma Mobile line of processors.
342	  If unsure, say N.
343
344config SERIAL_8250_RT288X
345	bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
346	depends on SERIAL_8250
347	default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
348	help
349	  Selecting this option will add support for the alternate register
350	  layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
351	  If unsure, say N.
352
353config SERIAL_8250_OMAP
354	tristate "Support for OMAP internal UART (8250 based driver)"
355	depends on SERIAL_8250 && ARCH_OMAP2PLUS
356	help
357	  If you have a machine based on an Texas Instruments OMAP CPU you
358	  can enable its onboard serial ports by enabling this option.
359
360	  This driver uses ttyS instead of ttyO.
361
362config SERIAL_8250_OMAP_TTYO_FIXUP
363	bool "Replace ttyO with ttyS"
364	depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
365	default y
366	help
367	  This option replaces the "console=ttyO" argument with the matching
368	  ttyS argument if the user did not specified it on the command line.
369	  This ensures that the user can see the kernel output during boot
370	  which he wouldn't see otherwise. The getty has still to be configured
371	  for ttyS instead of ttyO regardless of this option.
372	  This option is intended for people who "automatically" enable this
373	  driver without knowing that this driver requires a different console=
374	  argument. If you read this, please keep this option disabled and
375	  instead update your kernel command line. If you prepare a kernel for a
376	  distribution or other kind of larger user base then you probably want
377	  to keep this option enabled. Otherwise people might complain about a
378	  not booting kernel because the serial console remains silent in case
379	  they forgot to update the command line.
380
381config SERIAL_8250_LPC18XX
382	tristate "NXP LPC18xx/43xx serial port support"
383	depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
384	default ARCH_LPC18XX
385	help
386	  If you have a LPC18xx/43xx based board and want to use the
387	  serial port, say Y to this option. If unsure, say Y.
388
389config SERIAL_8250_MT6577
390	tristate "Mediatek serial port support"
391	depends on SERIAL_8250 && ARCH_MEDIATEK
392	help
393	  If you have a Mediatek based board and want to use the
394	  serial port, say Y to this option. If unsure, say N.
395
396config SERIAL_8250_UNIPHIER
397	tristate "Support for UniPhier on-chip UART"
398	depends on SERIAL_8250
399	depends on ARCH_UNIPHIER || COMPILE_TEST
400	help
401	  If you have a UniPhier based board and want to use the on-chip
402	  serial ports, say Y to this option. If unsure, say N.
403
404config SERIAL_8250_INGENIC
405	tristate "Support for Ingenic SoC serial ports"
406	depends on SERIAL_8250
407	depends on OF_FLATTREE
408	depends on MIPS || COMPILE_TEST
409	help
410	  If you have a system using an Ingenic SoC and wish to make use of
411	  its UARTs, say Y to this option. If unsure, say N.
412
413config SERIAL_8250_LPSS
414	tristate "Support for serial ports on Intel LPSS platforms"
415	default SERIAL_8250
416	depends on SERIAL_8250 && PCI
417	depends on X86 || COMPILE_TEST
418	select DW_DMAC_CORE if SERIAL_8250_DMA
419	select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
420	select RATIONAL
421	help
422	  Selecting this option will enable handling of the extra features
423	  present on the UART found on various Intel platforms such as:
424	    - Intel Baytrail SoC
425	    - Intel Braswell SoC
426	    - Intel Quark X1000 SoC
427
428config SERIAL_8250_MID
429	tristate "Support for serial ports on Intel MID platforms"
430	default SERIAL_8250
431	depends on SERIAL_8250 && PCI
432	depends on X86 || COMPILE_TEST
433	select HSU_DMA if SERIAL_8250_DMA
434	select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
435	select RATIONAL
436	help
437	  Selecting this option will enable handling of the extra features
438	  present on the UART found on Intel Medfield SOC and various other
439	  Intel platforms.
440
441config SERIAL_8250_MOXA
442	tristate "MOXA SmartIO MUE support"
443	depends on SERIAL_8250 && PCI
444	help
445	  Say Y here if you have a Moxa SmartIO MUE multiport serial card.
446	  If unsure, say N.
447
448	  This driver can also be built as a module. The module will be called
449	  8250_moxa. If you want to do that, say M here.
450
451config SERIAL_8250_PXA
452	tristate "PXA serial port support"
453	depends on SERIAL_8250
454	depends on ARCH_PXA || ARCH_MMP
455	help
456	  If you have a machine based on an Intel XScale PXA2xx CPU you can
457	  enable its onboard serial ports by enabling this option. The option is
458	  applicable to both devicetree and legacy boards, and early console is
459	  part of its support.
460
461config SERIAL_OF_PLATFORM
462	tristate "Devicetree based probing for 8250 ports"
463	depends on SERIAL_8250 && OF
464	help
465	  This option is used for all 8250 compatible serial ports that
466	  are probed through devicetree, including Open Firmware based
467	  PowerPC systems and embedded systems on architectures using the
468	  flattened device tree format.
469