xref: /openbmc/linux/drivers/tty/serial/8250/Kconfig (revision 56bbd862)
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" if EXPERT
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_HP300
131	tristate
132	depends on SERIAL_8250 && HP300
133	default SERIAL_8250
134
135config SERIAL_8250_CS
136	tristate "8250/16550 PCMCIA device support"
137	depends on PCMCIA && SERIAL_8250
138	---help---
139	  Say Y here to enable support for 16-bit PCMCIA serial devices,
140	  including serial port cards, modems, and the modem functions of
141	  multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
142	  credit-card size devices often used with laptops.)
143
144	  To compile this driver as a module, choose M here: the
145	  module will be called serial_cs.
146
147	  If unsure, say N.
148
149config SERIAL_8250_NR_UARTS
150	int "Maximum number of 8250/16550 serial ports"
151	depends on SERIAL_8250
152	default "4"
153	help
154	  Set this to the number of serial ports you want the driver
155	  to support.  This includes any ports discovered via ACPI or
156	  PCI enumeration and any ports that may be added at run-time
157	  via hot-plug, or any ISA multi-port serial cards.
158
159config SERIAL_8250_RUNTIME_UARTS
160	int "Number of 8250/16550 serial ports to register at runtime"
161	depends on SERIAL_8250
162	range 0 SERIAL_8250_NR_UARTS
163	default "4"
164	help
165	  Set this to the maximum number of serial ports you want
166	  the kernel to register at boot time.  This can be overridden
167	  with the module parameter "nr_uarts", or boot-time parameter
168	  8250.nr_uarts
169
170config SERIAL_8250_EXTENDED
171	bool "Extended 8250/16550 serial driver options"
172	depends on SERIAL_8250
173	help
174	  If you wish to use any non-standard features of the standard "dumb"
175	  driver, say Y here. This includes HUB6 support, shared serial
176	  interrupts, special multiport support, support for more than the
177	  four COM 1/2/3/4 boards, etc.
178
179	  Note that the answer to this question won't directly affect the
180	  kernel: saying N will just cause the configurator to skip all
181	  the questions about serial driver options. If unsure, say N.
182
183config SERIAL_8250_MANY_PORTS
184	bool "Support more than 4 legacy serial ports"
185	depends on SERIAL_8250_EXTENDED && !IA64
186	help
187	  Say Y here if you have dumb serial boards other than the four
188	  standard COM 1/2/3/4 ports. This may happen if you have an AST
189	  FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
190	  from <http://www.tldp.org/docs.html#howto>), or other custom
191	  serial port hardware which acts similar to standard serial port
192	  hardware. If you only use the standard COM 1/2/3/4 ports, you can
193	  say N here to save some memory. You can also say Y if you have an
194	  "intelligent" multiport card such as Cyclades, Digiboards, etc.
195
196#
197# Multi-port serial cards
198#
199
200config SERIAL_8250_FOURPORT
201	tristate "Support Fourport cards"
202	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
203	help
204	  Say Y here if you have an AST FourPort serial board.
205
206	  To compile this driver as a module, choose M here: the module
207	  will be called 8250_fourport.
208
209config SERIAL_8250_ACCENT
210	tristate "Support Accent cards"
211	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
212	help
213	  Say Y here if you have an Accent Async serial board.
214
215	  To compile this driver as a module, choose M here: the module
216	  will be called 8250_accent.
217
218config SERIAL_8250_BOCA
219	tristate "Support Boca cards"
220	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
221	help
222	  Say Y here if you have a Boca serial board.  Please read the Boca
223	  mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
224
225	  To compile this driver as a module, choose M here: the module
226	  will be called 8250_boca.
227
228config SERIAL_8250_EXAR_ST16C554
229	tristate "Support Exar ST16C554/554D Quad UART"
230	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
231	help
232	  The Uplogix Envoy TU301 uses this Exar Quad UART.  If you are
233	  tinkering with your Envoy TU301, or have a machine with this UART,
234	  say Y here.
235
236	  To compile this driver as a module, choose M here: the module
237	  will be called 8250_exar_st16c554.
238
239config SERIAL_8250_HUB6
240	tristate "Support Hub6 cards"
241	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
242	help
243	  Say Y here if you have a HUB6 serial board.
244
245	  To compile this driver as a module, choose M here: the module
246	  will be called 8250_hub6.
247
248#
249# Misc. options/drivers.
250#
251
252config SERIAL_8250_SHARE_IRQ
253	bool "Support for sharing serial interrupts"
254	depends on SERIAL_8250_EXTENDED
255	help
256	  Some serial boards have hardware support which allows multiple dumb
257	  serial ports on the same board to share a single IRQ. To enable
258	  support for this in the serial driver, say Y here.
259
260config SERIAL_8250_DETECT_IRQ
261	bool "Autodetect IRQ on standard ports (unsafe)"
262	depends on SERIAL_8250_EXTENDED
263	help
264	  Say Y here if you want the kernel to try to guess which IRQ
265	  to use for your serial port.
266
267	  This is considered unsafe; it is far better to configure the IRQ in
268	  a boot script using the setserial command.
269
270	  If unsure, say N.
271
272config SERIAL_8250_RSA
273	bool "Support RSA serial ports"
274	depends on SERIAL_8250_EXTENDED
275	help
276	  Say Y here if you have a IODATA RSA-DV II/S ISA card and
277	  would like to use its >115kbps speeds.
278	  You will need to provide module parameter "probe_rsa", or boot-time
279	  parameter 8250.probe_rsa with I/O addresses of this card then.
280
281	  If you don't have such card, or if unsure, say N.
282
283config SERIAL_8250_ACORN
284	tristate "Acorn expansion card serial port support"
285	depends on ARCH_ACORN && SERIAL_8250
286	help
287	  If you have an Atomwide Serial card or Serial Port card for an Acorn
288	  system, say Y to this option.  The driver can handle 1, 2, or 3 port
289	  cards.  If unsure, say N.
290
291config SERIAL_8250_BCM2835AUX
292	tristate "BCM2835 auxiliar mini UART support"
293	depends on ARCH_BCM2835 || COMPILE_TEST
294	depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
295	help
296	  Support for the BCM2835 auxiliar mini UART.
297
298	  Features and limitations of the UART are
299	    Registers are similar to 16650 registers,
300              set bits in the control registers that are unsupported
301	      are ignored and read back as 0
302	    7/8 bit operation with 1 start and 1 stop bit
303	    8 symbols deep fifo for rx and tx
304	    SW controlled RTS and SW readable CTS
305	    Clock rate derived from system clock
306	    Uses 8 times oversampling (compared to 16 times for 16650)
307	    Missing break detection (but break generation)
308	    Missing framing error detection
309	    Missing parity bit
310	    Missing receive time-out interrupt
311	    Missing DCD, DSR, DTR and RI signals
312
313	  If unsure, say N.
314
315config SERIAL_8250_FSL
316	bool
317	depends on SERIAL_8250_CONSOLE
318	default PPC || ARM || ARM64
319
320config SERIAL_8250_DW
321	tristate "Support for Synopsys DesignWare 8250 quirks"
322	depends on SERIAL_8250
323	help
324	  Selecting this option will enable handling of the extra features
325	  present in the Synopsys DesignWare APB UART.
326
327config SERIAL_8250_EM
328	tristate "Support for Emma Mobile integrated serial port"
329	depends on SERIAL_8250 && ARM && HAVE_CLK
330	help
331	  Selecting this option will add support for the integrated serial
332	  port hardware found on the Emma Mobile line of processors.
333	  If unsure, say N.
334
335config SERIAL_8250_RT288X
336	bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
337	depends on SERIAL_8250
338	default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
339	help
340	  Selecting this option will add support for the alternate register
341	  layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
342	  If unsure, say N.
343
344config SERIAL_8250_OMAP
345	tristate "Support for OMAP internal UART (8250 based driver)"
346	depends on SERIAL_8250 && ARCH_OMAP2PLUS
347	help
348	  If you have a machine based on an Texas Instruments OMAP CPU you
349	  can enable its onboard serial ports by enabling this option.
350
351	  This driver uses ttyS instead of ttyO.
352
353config SERIAL_8250_OMAP_TTYO_FIXUP
354	bool "Replace ttyO with ttyS"
355	depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
356	default y
357	help
358	  This option replaces the "console=ttyO" argument with the matching
359	  ttyS argument if the user did not specified it on the command line.
360	  This ensures that the user can see the kernel output during boot
361	  which he wouldn't see otherwise. The getty has still to be configured
362	  for ttyS instead of ttyO regardless of this option.
363	  This option is intended for people who "automatically" enable this
364	  driver without knowing that this driver requires a different console=
365	  argument. If you read this, please keep this option disabled and
366	  instead update your kernel command line. If you prepare a kernel for a
367	  distribution or other kind of larger user base then you probably want
368	  to keep this option enabled. Otherwise people might complain about a
369	  not booting kernel because the serial console remains silent in case
370	  they forgot to update the command line.
371
372config SERIAL_8250_LPC18XX
373	tristate "NXP LPC18xx/43xx serial port support"
374	depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
375	default ARCH_LPC18XX
376	help
377	  If you have a LPC18xx/43xx based board and want to use the
378	  serial port, say Y to this option. If unsure, say Y.
379
380config SERIAL_8250_MT6577
381	tristate "Mediatek serial port support"
382	depends on SERIAL_8250 && ARCH_MEDIATEK
383	help
384	  If you have a Mediatek based board and want to use the
385	  serial port, say Y to this option. If unsure, say N.
386
387config SERIAL_8250_UNIPHIER
388	tristate "Support for UniPhier on-chip UART"
389	depends on SERIAL_8250
390	depends on ARCH_UNIPHIER || COMPILE_TEST
391	help
392	  If you have a UniPhier based board and want to use the on-chip
393	  serial ports, say Y to this option. If unsure, say N.
394
395config SERIAL_8250_INGENIC
396	tristate "Support for Ingenic SoC serial ports"
397	depends on SERIAL_8250
398	depends on OF_FLATTREE
399	depends on MIPS || COMPILE_TEST
400	help
401	  If you have a system using an Ingenic SoC and wish to make use of
402	  its UARTs, say Y to this option. If unsure, say N.
403
404config SERIAL_8250_LPSS
405	tristate "Support for serial ports on Intel LPSS platforms" if EXPERT
406	default SERIAL_8250
407	depends on SERIAL_8250 && PCI
408	depends on X86 || COMPILE_TEST
409	select DW_DMAC_CORE if SERIAL_8250_DMA
410	select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
411	select RATIONAL
412	help
413	  Selecting this option will enable handling of the extra features
414	  present on the UART found on various Intel platforms such as:
415	    - Intel Baytrail SoC
416	    - Intel Braswell SoC
417	    - Intel Quark X1000 SoC
418
419config SERIAL_8250_MID
420	tristate "Support for serial ports on Intel MID platforms" if EXPERT
421	default SERIAL_8250
422	depends on SERIAL_8250 && PCI
423	depends on X86 || COMPILE_TEST
424	select HSU_DMA if SERIAL_8250_DMA
425	select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
426	select RATIONAL
427	help
428	  Selecting this option will enable handling of the extra features
429	  present on the UART found on Intel Medfield SOC and various other
430	  Intel platforms.
431
432config SERIAL_8250_MOXA
433	tristate "MOXA SmartIO MUE support"
434	depends on SERIAL_8250 && PCI
435	help
436	  Say Y here if you have a Moxa SmartIO MUE multiport serial card.
437	  If unsure, say N.
438
439	  This driver can also be built as a module. The module will be called
440	  8250_moxa. If you want to do that, say M here.
441
442config SERIAL_8250_PXA
443	tristate "PXA serial port support"
444	depends on SERIAL_8250
445	depends on ARCH_PXA || ARCH_MMP
446	help
447	  If you have a machine based on an Intel XScale PXA2xx CPU you can
448	  enable its onboard serial ports by enabling this option. The option is
449	  applicable to both devicetree and legacy boards, and early console is
450	  part of its support.
451
452config SERIAL_OF_PLATFORM
453	tristate "Devicetree based probing for 8250 ports"
454	depends on SERIAL_8250 && OF
455	help
456	  This option is used for all 8250 compatible serial ports that
457	  are probed through devicetree, including Open Firmware based
458	  PowerPC systems and embedded systems on architectures using the
459	  flattened device tree format.
460