xref: /linux/drivers/tty/serial/8250/Kconfig (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
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	select SERIAL_MCTRL_GPIO if GPIOLIB
10	---help---
11	  This selects whether you want to include the driver for the standard
12	  serial ports.  The standard answer is Y.  People who might say N
13	  here are those that are setting up dedicated Ethernet WWW/FTP
14	  servers, or users that have one of the various bus mice instead of a
15	  serial mouse and don't intend to use their machine's standard serial
16	  port for anything.  (Note that the Cyclades multi serial port driver
17	  does not need this driver built in for it to work.)
18
19	  To compile this driver as a module, choose M here: the
20	  module will be called 8250.
21	  [WARNING: Do not compile this driver as a module if you are using
22	  non-standard serial ports, since the configuration information will
23	  be lost when the driver is unloaded.  This limitation may be lifted
24	  in the future.]
25
26	  BTW1: If you have a mouseman serial mouse which is not recognized by
27	  the X window system, try running gpm first.
28
29	  BTW2: If you intend to use a software modem (also called Winmodem)
30	  under Linux, forget it.  These modems are crippled and require
31	  proprietary drivers which are only available under Windows.
32
33	  Most people will say Y or M here, so that they can use serial mice,
34	  modems and similar devices connecting to the standard serial ports.
35
36config SERIAL_8250_DEPRECATED_OPTIONS
37	bool "Support 8250_core.* kernel options (DEPRECATED)"
38	depends on SERIAL_8250
39	default y
40	---help---
41	  In 3.7 we renamed 8250 to 8250_core by mistake, so now we have to
42	  accept kernel parameters in both forms like 8250_core.nr_uarts=4 and
43	  8250.nr_uarts=4. We now renamed the module back to 8250, but if
44	  anybody noticed in 3.7 and changed their userspace we still have to
45	  keep the 8250_core.* options around until they revert the changes
46	  they already did.
47
48	  If 8250 is built as a module, this adds 8250_core alias instead.
49
50	  If you did not notice yet and/or you have userspace from pre-3.7, it
51	  is safe (and recommended) to say N here.
52
53config SERIAL_8250_PNP
54	bool "8250/16550 PNP device support" if EXPERT
55	depends on SERIAL_8250 && PNP
56	default y
57	---help---
58	  This builds standard PNP serial support. You may be able to
59	  disable this feature if you only need legacy serial support.
60
61config SERIAL_8250_FINTEK
62	bool "Support for Fintek F81216A LPC to 4 UART RS485 API"
63	depends on SERIAL_8250
64	---help---
65	  Selecting this option will add support for the RS485 capabilities
66	  of the Fintek F81216A LPC to 4 UART.
67
68	  If this option is not selected the device will be configured as a
69	  standard 16550A serial port.
70
71	  If unsure, say N.
72
73config SERIAL_8250_CONSOLE
74	bool "Console on 8250/16550 and compatible serial port"
75	depends on SERIAL_8250=y
76	select SERIAL_CORE_CONSOLE
77	select SERIAL_EARLYCON
78	---help---
79	  If you say Y here, it will be possible to use a serial port as the
80	  system console (the system console is the device which receives all
81	  kernel messages and warnings and which allows logins in single user
82	  mode). This could be useful if some terminal or printer is connected
83	  to that serial port.
84
85	  Even if you say Y here, the currently visible virtual console
86	  (/dev/tty0) will still be used as the system console by default, but
87	  you can alter that using a kernel command line option such as
88	  "console=ttyS1". (Try "man bootparam" or see the documentation of
89	  your boot loader (grub or lilo or loadlin) about how to pass options
90	  to the kernel at boot time.)
91
92	  If you don't have a VGA card installed and you say Y here, the
93	  kernel will automatically use the first serial line, /dev/ttyS0, as
94	  system console.
95
96	  You can set that using a kernel command line option such as
97	  "console=uart8250,io,0x3f8,9600n8"
98	  "console=uart8250,mmio,0xff5e0000,115200n8".
99	  and it will switch to normal serial console when the corresponding
100	  port is ready.
101	  "earlycon=uart8250,io,0x3f8,9600n8"
102	  "earlycon=uart8250,mmio,0xff5e0000,115200n8".
103	  it will not only setup early console.
104
105	  If unsure, say N.
106
107config SERIAL_8250_GSC
108	tristate
109	depends on SERIAL_8250 && GSC
110	default SERIAL_8250
111
112config SERIAL_8250_DMA
113	bool "DMA support for 16550 compatible UART controllers" if EXPERT
114	depends on SERIAL_8250 && DMADEVICES=y
115	default SERIAL_8250
116	help
117	  This builds DMA support that can be used with 8250/16650
118	  compatible UART controllers that support DMA signaling.
119
120config SERIAL_8250_PCI
121	tristate "8250/16550 PCI device support" if EXPERT
122	depends on SERIAL_8250 && PCI
123	default SERIAL_8250
124	select RATIONAL
125	help
126	  This builds standard PCI serial support. You may be able to
127	  disable this feature if you only need legacy serial support.
128	  Saves about 9K.
129	  Note that serial ports on NetMos 9835 Multi-I/O cards are handled
130	  by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL.
131
132config SERIAL_8250_HP300
133	tristate
134	depends on SERIAL_8250 && HP300
135	default SERIAL_8250
136
137config SERIAL_8250_CS
138	tristate "8250/16550 PCMCIA device support"
139	depends on PCMCIA && SERIAL_8250
140	---help---
141	  Say Y here to enable support for 16-bit PCMCIA serial devices,
142	  including serial port cards, modems, and the modem functions of
143	  multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
144	  credit-card size devices often used with laptops.)
145
146	  To compile this driver as a module, choose M here: the
147	  module will be called serial_cs.
148
149	  If unsure, say N.
150
151config SERIAL_8250_NR_UARTS
152	int "Maximum number of 8250/16550 serial ports"
153	depends on SERIAL_8250
154	default "4"
155	help
156	  Set this to the number of serial ports you want the driver
157	  to support.  This includes any ports discovered via ACPI or
158	  PCI enumeration and any ports that may be added at run-time
159	  via hot-plug, or any ISA multi-port serial cards.
160
161config SERIAL_8250_RUNTIME_UARTS
162	int "Number of 8250/16550 serial ports to register at runtime"
163	depends on SERIAL_8250
164	range 0 SERIAL_8250_NR_UARTS
165	default "4"
166	help
167	  Set this to the maximum number of serial ports you want
168	  the kernel to register at boot time.  This can be overridden
169	  with the module parameter "nr_uarts", or boot-time parameter
170	  8250.nr_uarts
171
172config SERIAL_8250_EXTENDED
173	bool "Extended 8250/16550 serial driver options"
174	depends on SERIAL_8250
175	help
176	  If you wish to use any non-standard features of the standard "dumb"
177	  driver, say Y here. This includes HUB6 support, shared serial
178	  interrupts, special multiport support, support for more than the
179	  four COM 1/2/3/4 boards, etc.
180
181	  Note that the answer to this question won't directly affect the
182	  kernel: saying N will just cause the configurator to skip all
183	  the questions about serial driver options. If unsure, say N.
184
185config SERIAL_8250_MANY_PORTS
186	bool "Support more than 4 legacy serial ports"
187	depends on SERIAL_8250_EXTENDED && !IA64
188	help
189	  Say Y here if you have dumb serial boards other than the four
190	  standard COM 1/2/3/4 ports. This may happen if you have an AST
191	  FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
192	  from <http://www.tldp.org/docs.html#howto>), or other custom
193	  serial port hardware which acts similar to standard serial port
194	  hardware. If you only use the standard COM 1/2/3/4 ports, you can
195	  say N here to save some memory. You can also say Y if you have an
196	  "intelligent" multiport card such as Cyclades, Digiboards, etc.
197
198#
199# Multi-port serial cards
200#
201
202config SERIAL_8250_FOURPORT
203	tristate "Support Fourport cards"
204	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
205	help
206	  Say Y here if you have an AST FourPort serial board.
207
208	  To compile this driver as a module, choose M here: the module
209	  will be called 8250_fourport.
210
211config SERIAL_8250_ACCENT
212	tristate "Support Accent cards"
213	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
214	help
215	  Say Y here if you have an Accent Async serial board.
216
217	  To compile this driver as a module, choose M here: the module
218	  will be called 8250_accent.
219
220config SERIAL_8250_BOCA
221	tristate "Support Boca cards"
222	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
223	help
224	  Say Y here if you have a Boca serial board.  Please read the Boca
225	  mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
226
227	  To compile this driver as a module, choose M here: the module
228	  will be called 8250_boca.
229
230config SERIAL_8250_EXAR_ST16C554
231	tristate "Support Exar ST16C554/554D Quad UART"
232	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
233	help
234	  The Uplogix Envoy TU301 uses this Exar Quad UART.  If you are
235	  tinkering with your Envoy TU301, or have a machine with this UART,
236	  say Y here.
237
238	  To compile this driver as a module, choose M here: the module
239	  will be called 8250_exar_st16c554.
240
241config SERIAL_8250_HUB6
242	tristate "Support Hub6 cards"
243	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
244	help
245	  Say Y here if you have a HUB6 serial board.
246
247	  To compile this driver as a module, choose M here: the module
248	  will be called 8250_hub6.
249
250#
251# Misc. options/drivers.
252#
253
254config SERIAL_8250_SHARE_IRQ
255	bool "Support for sharing serial interrupts"
256	depends on SERIAL_8250_EXTENDED
257	help
258	  Some serial boards have hardware support which allows multiple dumb
259	  serial ports on the same board to share a single IRQ. To enable
260	  support for this in the serial driver, say Y here.
261
262config SERIAL_8250_DETECT_IRQ
263	bool "Autodetect IRQ on standard ports (unsafe)"
264	depends on SERIAL_8250_EXTENDED
265	help
266	  Say Y here if you want the kernel to try to guess which IRQ
267	  to use for your serial port.
268
269	  This is considered unsafe; it is far better to configure the IRQ in
270	  a boot script using the setserial command.
271
272	  If unsure, say N.
273
274config SERIAL_8250_RSA
275	bool "Support RSA serial ports"
276	depends on SERIAL_8250_EXTENDED
277	help
278	  Say Y here if you have a IODATA RSA-DV II/S ISA card and
279	  would like to use its >115kbps speeds.
280	  You will need to provide module parameter "probe_rsa", or boot-time
281	  parameter 8250.probe_rsa with I/O addresses of this card then.
282
283	  If you don't have such card, or if unsure, say N.
284
285config SERIAL_8250_ACORN
286	tristate "Acorn expansion card serial port support"
287	depends on ARCH_ACORN && SERIAL_8250
288	help
289	  If you have an Atomwide Serial card or Serial Port card for an Acorn
290	  system, say Y to this option.  The driver can handle 1, 2, or 3 port
291	  cards.  If unsure, say N.
292
293config SERIAL_8250_BCM2835AUX
294	tristate "BCM2835 auxiliar mini UART support"
295	depends on ARCH_BCM2835 || COMPILE_TEST
296	depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
297	help
298	  Support for the BCM2835 auxiliar mini UART.
299
300	  Features and limitations of the UART are
301	    Registers are similar to 16650 registers,
302              set bits in the control registers that are unsupported
303	      are ignored and read back as 0
304	    7/8 bit operation with 1 start and 1 stop bit
305	    8 symbols deep fifo for rx and tx
306	    SW controlled RTS and SW readable CTS
307	    Clock rate derived from system clock
308	    Uses 8 times oversampling (compared to 16 times for 16650)
309	    Missing break detection (but break generation)
310	    Missing framing error detection
311	    Missing parity bit
312	    Missing receive time-out interrupt
313	    Missing DCD, DSR, DTR and RI signals
314
315	  If unsure, say N.
316
317config SERIAL_8250_FSL
318	bool
319	depends on SERIAL_8250_CONSOLE
320	default PPC || ARM || ARM64
321
322config SERIAL_8250_DW
323	tristate "Support for Synopsys DesignWare 8250 quirks"
324	depends on SERIAL_8250
325	help
326	  Selecting this option will enable handling of the extra features
327	  present in the Synopsys DesignWare APB UART.
328
329config SERIAL_8250_EM
330	tristate "Support for Emma Mobile integrated serial port"
331	depends on SERIAL_8250 && ARM && HAVE_CLK
332	help
333	  Selecting this option will add support for the integrated serial
334	  port hardware found on the Emma Mobile line of processors.
335	  If unsure, say N.
336
337config SERIAL_8250_RT288X
338	bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
339	depends on SERIAL_8250
340	default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
341	help
342	  Selecting this option will add support for the alternate register
343	  layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
344	  If unsure, say N.
345
346config SERIAL_8250_OMAP
347	tristate "Support for OMAP internal UART (8250 based driver)"
348	depends on SERIAL_8250 && ARCH_OMAP2PLUS
349	help
350	  If you have a machine based on an Texas Instruments OMAP CPU you
351	  can enable its onboard serial ports by enabling this option.
352
353	  This driver uses ttyS instead of ttyO.
354
355config SERIAL_8250_OMAP_TTYO_FIXUP
356	bool "Replace ttyO with ttyS"
357	depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
358	default y
359	help
360	  This option replaces the "console=ttyO" argument with the matching
361	  ttyS argument if the user did not specified it on the command line.
362	  This ensures that the user can see the kernel output during boot
363	  which he wouldn't see otherwise. The getty has still to be configured
364	  for ttyS instead of ttyO regardless of this option.
365	  This option is intended for people who "automatically" enable this
366	  driver without knowing that this driver requires a different console=
367	  argument. If you read this, please keep this option disabled and
368	  instead update your kernel command line. If you prepare a kernel for a
369	  distribution or other kind of larger user base then you probably want
370	  to keep this option enabled. Otherwise people might complain about a
371	  not booting kernel because the serial console remains silent in case
372	  they forgot to update the command line.
373
374config SERIAL_8250_LPC18XX
375	tristate "NXP LPC18xx/43xx serial port support"
376	depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
377	default ARCH_LPC18XX
378	help
379	  If you have a LPC18xx/43xx based board and want to use the
380	  serial port, say Y to this option. If unsure, say Y.
381
382config SERIAL_8250_MT6577
383	tristate "Mediatek serial port support"
384	depends on SERIAL_8250 && ARCH_MEDIATEK
385	help
386	  If you have a Mediatek based board and want to use the
387	  serial port, say Y to this option. If unsure, say N.
388
389config SERIAL_8250_UNIPHIER
390	tristate "Support for UniPhier on-chip UART"
391	depends on SERIAL_8250
392	depends on ARCH_UNIPHIER || COMPILE_TEST
393	help
394	  If you have a UniPhier based board and want to use the on-chip
395	  serial ports, say Y to this option. If unsure, say N.
396
397config SERIAL_8250_INGENIC
398	tristate "Support for Ingenic SoC serial ports"
399	depends on SERIAL_8250
400	depends on OF_FLATTREE
401	depends on MIPS || COMPILE_TEST
402	help
403	  If you have a system using an Ingenic SoC and wish to make use of
404	  its UARTs, say Y to this option. If unsure, say N.
405
406config SERIAL_8250_MID
407	tristate "Support for serial ports on Intel MID platforms" if EXPERT
408	default SERIAL_8250
409	depends on SERIAL_8250 && PCI
410	depends on X86 || COMPILE_TEST
411	select HSU_DMA if SERIAL_8250_DMA
412	select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
413	select RATIONAL
414	help
415	  Selecting this option will enable handling of the extra features
416	  present on the UART found on Intel Medfield SOC and various other
417	  Intel platforms.
418
419config SERIAL_8250_MOXA
420	tristate "MOXA SmartIO MUE support"
421	depends on SERIAL_8250 && PCI
422	help
423	  Say Y here if you have a Moxa SmartIO MUE multiport serial card.
424	  If unsure, say N.
425
426	  This driver can also be built as a module. The module will be called
427	  8250_moxa. If you want to do that, say M here.
428
429config SERIAL_OF_PLATFORM
430	tristate "Devicetree based probing for 8250 ports"
431	depends on SERIAL_8250 && OF
432	help
433	  This option is used for all 8250 compatible serial ports that
434	  are probed through devicetree, including Open Firmware based
435	  PowerPC systems and embedded systems on architectures using the
436	  flattened device tree format.
437