xref: /openbmc/linux/drivers/tty/serial/8250/Kconfig (revision bc5aa3a0)
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	select RATIONAL
124	help
125	  This builds standard PCI serial support. You may be able to
126	  disable this feature if you only need legacy serial support.
127	  Saves about 9K.
128	  Note that serial ports on NetMos 9835 Multi-I/O cards are handled
129	  by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL.
130
131config SERIAL_8250_HP300
132	tristate
133	depends on SERIAL_8250 && HP300
134	default SERIAL_8250
135
136config SERIAL_8250_CS
137	tristate "8250/16550 PCMCIA device support"
138	depends on PCMCIA && SERIAL_8250
139	---help---
140	  Say Y here to enable support for 16-bit PCMCIA serial devices,
141	  including serial port cards, modems, and the modem functions of
142	  multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
143	  credit-card size devices often used with laptops.)
144
145	  To compile this driver as a module, choose M here: the
146	  module will be called serial_cs.
147
148	  If unsure, say N.
149
150config SERIAL_8250_NR_UARTS
151	int "Maximum number of 8250/16550 serial ports"
152	depends on SERIAL_8250
153	default "4"
154	help
155	  Set this to the number of serial ports you want the driver
156	  to support.  This includes any ports discovered via ACPI or
157	  PCI enumeration and any ports that may be added at run-time
158	  via hot-plug, or any ISA multi-port serial cards.
159
160config SERIAL_8250_RUNTIME_UARTS
161	int "Number of 8250/16550 serial ports to register at runtime"
162	depends on SERIAL_8250
163	range 0 SERIAL_8250_NR_UARTS
164	default "4"
165	help
166	  Set this to the maximum number of serial ports you want
167	  the kernel to register at boot time.  This can be overridden
168	  with the module parameter "nr_uarts", or boot-time parameter
169	  8250.nr_uarts
170
171config SERIAL_8250_EXTENDED
172	bool "Extended 8250/16550 serial driver options"
173	depends on SERIAL_8250
174	help
175	  If you wish to use any non-standard features of the standard "dumb"
176	  driver, say Y here. This includes HUB6 support, shared serial
177	  interrupts, special multiport support, support for more than the
178	  four COM 1/2/3/4 boards, etc.
179
180	  Note that the answer to this question won't directly affect the
181	  kernel: saying N will just cause the configurator to skip all
182	  the questions about serial driver options. If unsure, say N.
183
184config SERIAL_8250_MANY_PORTS
185	bool "Support more than 4 legacy serial ports"
186	depends on SERIAL_8250_EXTENDED && !IA64
187	help
188	  Say Y here if you have dumb serial boards other than the four
189	  standard COM 1/2/3/4 ports. This may happen if you have an AST
190	  FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
191	  from <http://www.tldp.org/docs.html#howto>), or other custom
192	  serial port hardware which acts similar to standard serial port
193	  hardware. If you only use the standard COM 1/2/3/4 ports, you can
194	  say N here to save some memory. You can also say Y if you have an
195	  "intelligent" multiport card such as Cyclades, Digiboards, etc.
196
197#
198# Multi-port serial cards
199#
200
201config SERIAL_8250_FOURPORT
202	tristate "Support Fourport cards"
203	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
204	help
205	  Say Y here if you have an AST FourPort serial board.
206
207	  To compile this driver as a module, choose M here: the module
208	  will be called 8250_fourport.
209
210config SERIAL_8250_ACCENT
211	tristate "Support Accent cards"
212	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
213	help
214	  Say Y here if you have an Accent Async serial board.
215
216	  To compile this driver as a module, choose M here: the module
217	  will be called 8250_accent.
218
219config SERIAL_8250_BOCA
220	tristate "Support Boca cards"
221	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
222	help
223	  Say Y here if you have a Boca serial board.  Please read the Boca
224	  mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
225
226	  To compile this driver as a module, choose M here: the module
227	  will be called 8250_boca.
228
229config SERIAL_8250_EXAR_ST16C554
230	tristate "Support Exar ST16C554/554D Quad UART"
231	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
232	help
233	  The Uplogix Envoy TU301 uses this Exar Quad UART.  If you are
234	  tinkering with your Envoy TU301, or have a machine with this UART,
235	  say Y here.
236
237	  To compile this driver as a module, choose M here: the module
238	  will be called 8250_exar_st16c554.
239
240config SERIAL_8250_HUB6
241	tristate "Support Hub6 cards"
242	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
243	help
244	  Say Y here if you have a HUB6 serial board.
245
246	  To compile this driver as a module, choose M here: the module
247	  will be called 8250_hub6.
248
249#
250# Misc. options/drivers.
251#
252
253config SERIAL_8250_SHARE_IRQ
254	bool "Support for sharing serial interrupts"
255	depends on SERIAL_8250_EXTENDED
256	help
257	  Some serial boards have hardware support which allows multiple dumb
258	  serial ports on the same board to share a single IRQ. To enable
259	  support for this in the serial driver, say Y here.
260
261config SERIAL_8250_DETECT_IRQ
262	bool "Autodetect IRQ on standard ports (unsafe)"
263	depends on SERIAL_8250_EXTENDED
264	help
265	  Say Y here if you want the kernel to try to guess which IRQ
266	  to use for your serial port.
267
268	  This is considered unsafe; it is far better to configure the IRQ in
269	  a boot script using the setserial command.
270
271	  If unsure, say N.
272
273config SERIAL_8250_RSA
274	bool "Support RSA serial ports"
275	depends on SERIAL_8250_EXTENDED
276	help
277	  Say Y here if you have a IODATA RSA-DV II/S ISA card and
278	  would like to use its >115kbps speeds.
279	  You will need to provide module parameter "probe_rsa", or boot-time
280	  parameter 8250.probe_rsa with I/O addresses of this card then.
281
282	  If you don't have such card, or if unsure, say N.
283
284config SERIAL_8250_ACORN
285	tristate "Acorn expansion card serial port support"
286	depends on ARCH_ACORN && SERIAL_8250
287	help
288	  If you have an Atomwide Serial card or Serial Port card for an Acorn
289	  system, say Y to this option.  The driver can handle 1, 2, or 3 port
290	  cards.  If unsure, say N.
291
292config SERIAL_8250_BCM2835AUX
293	tristate "BCM2835 auxiliar mini UART support"
294	depends on ARCH_BCM2835 || COMPILE_TEST
295	depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
296	help
297	  Support for the BCM2835 auxiliar mini UART.
298
299	  Features and limitations of the UART are
300	    Registers are similar to 16650 registers,
301              set bits in the control registers that are unsupported
302	      are ignored and read back as 0
303	    7/8 bit operation with 1 start and 1 stop bit
304	    8 symbols deep fifo for rx and tx
305	    SW controlled RTS and SW readable CTS
306	    Clock rate derived from system clock
307	    Uses 8 times oversampling (compared to 16 times for 16650)
308	    Missing break detection (but break generation)
309	    Missing framing error detection
310	    Missing parity bit
311	    Missing receive time-out interrupt
312	    Missing DCD, DSR, DTR and RI signals
313
314	  If unsure, say N.
315
316config SERIAL_8250_FSL
317	bool
318	depends on SERIAL_8250_CONSOLE
319	default PPC || ARM || ARM64
320
321config SERIAL_8250_DW
322	tristate "Support for Synopsys DesignWare 8250 quirks"
323	depends on SERIAL_8250
324	help
325	  Selecting this option will enable handling of the extra features
326	  present in the Synopsys DesignWare APB UART.
327
328config SERIAL_8250_EM
329	tristate "Support for Emma Mobile integrated serial port"
330	depends on SERIAL_8250 && ARM && HAVE_CLK
331	help
332	  Selecting this option will add support for the integrated serial
333	  port hardware found on the Emma Mobile line of processors.
334	  If unsure, say N.
335
336config SERIAL_8250_RT288X
337	bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
338	depends on SERIAL_8250
339	default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
340	help
341	  Selecting this option will add support for the alternate register
342	  layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
343	  If unsure, say N.
344
345config SERIAL_8250_OMAP
346	tristate "Support for OMAP internal UART (8250 based driver)"
347	depends on SERIAL_8250 && ARCH_OMAP2PLUS
348	help
349	  If you have a machine based on an Texas Instruments OMAP CPU you
350	  can enable its onboard serial ports by enabling this option.
351
352	  This driver uses ttyS instead of ttyO.
353
354config SERIAL_8250_OMAP_TTYO_FIXUP
355	bool "Replace ttyO with ttyS"
356	depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
357	default y
358	help
359	  This option replaces the "console=ttyO" argument with the matching
360	  ttyS argument if the user did not specified it on the command line.
361	  This ensures that the user can see the kernel output during boot
362	  which he wouldn't see otherwise. The getty has still to be configured
363	  for ttyS instead of ttyO regardless of this option.
364	  This option is intended for people who "automatically" enable this
365	  driver without knowing that this driver requires a different console=
366	  argument. If you read this, please keep this option disabled and
367	  instead update your kernel command line. If you prepare a kernel for a
368	  distribution or other kind of larger user base then you probably want
369	  to keep this option enabled. Otherwise people might complain about a
370	  not booting kernel because the serial console remains silent in case
371	  they forgot to update the command line.
372
373config SERIAL_8250_LPC18XX
374	tristate "NXP LPC18xx/43xx serial port support"
375	depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
376	default ARCH_LPC18XX
377	help
378	  If you have a LPC18xx/43xx based board and want to use the
379	  serial port, say Y to this option. If unsure, say Y.
380
381config SERIAL_8250_MT6577
382	tristate "Mediatek serial port support"
383	depends on SERIAL_8250 && ARCH_MEDIATEK
384	help
385	  If you have a Mediatek based board and want to use the
386	  serial port, say Y to this option. If unsure, say N.
387
388config SERIAL_8250_UNIPHIER
389	tristate "Support for UniPhier on-chip UART"
390	depends on SERIAL_8250
391	depends on ARCH_UNIPHIER || COMPILE_TEST
392	help
393	  If you have a UniPhier based board and want to use the on-chip
394	  serial ports, say Y to this option. If unsure, say N.
395
396config SERIAL_8250_INGENIC
397	tristate "Support for Ingenic SoC serial ports"
398	depends on SERIAL_8250
399	depends on OF_FLATTREE
400	depends on MIPS || COMPILE_TEST
401	help
402	  If you have a system using an Ingenic SoC and wish to make use of
403	  its UARTs, say Y to this option. If unsure, say N.
404
405config SERIAL_8250_MID
406	tristate "Support for serial ports on Intel MID platforms" if EXPERT
407	default SERIAL_8250
408	depends on SERIAL_8250 && PCI
409	depends on X86 || COMPILE_TEST
410	select HSU_DMA if SERIAL_8250_DMA
411	select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
412	select RATIONAL
413	help
414	  Selecting this option will enable handling of the extra features
415	  present on the UART found on Intel Medfield SOC and various other
416	  Intel platforms.
417
418config SERIAL_8250_MOXA
419	tristate "MOXA SmartIO MUE support"
420	depends on SERIAL_8250 && PCI
421	help
422	  Say Y here if you have a Moxa SmartIO MUE multiport serial card.
423	  If unsure, say N.
424
425	  This driver can also be built as a module. The module will be called
426	  8250_moxa. If you want to do that, say M here.
427
428config SERIAL_OF_PLATFORM
429	tristate "Devicetree based probing for 8250 ports"
430	depends on SERIAL_8250 && OF
431	help
432	  This option is used for all 8250 compatible serial ports that
433	  are probed through devicetree, including Open Firmware based
434	  PowerPC systems and embedded systems on architectures using the
435	  flattened device tree format.
436