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1# SPDX-License-Identifier: GPL-2.0
2#
3# The 8250/16550 serial drivers. You shouldn't be in this list unless
4# you somehow have an implicit or explicit dependency on SERIAL_8250.
5#
6
7config SERIAL_8250
8 tristate "8250/16550 and compatible serial support"
9 depends on !S390
10 select SERIAL_CORE
11 select SERIAL_MCTRL_GPIO if GPIOLIB
12 help
13 This selects whether you want to include the driver for the standard
14 serial ports. The standard answer is Y. People who might say N
15 here are those that are setting up dedicated Ethernet WWW/FTP
16 servers, or users that have one of the various bus mice instead of a
17 serial mouse and don't intend to use their machine's standard serial
18 port for anything.
19
20 To compile this driver as a module, choose M here: the
21 module will be called 8250.
22 [WARNING: Do not compile this driver as a module if you are using
23 non-standard serial ports, since the configuration information will
24 be lost when the driver is unloaded. This limitation may be lifted
25 in the future.]
26
27 BTW1: If you have a mouseman serial mouse which is not recognized by
28 the X window system, try running gpm first.
29
30 BTW2: If you intend to use a software modem (also called Winmodem)
31 under Linux, forget it. These modems are crippled and require
32 proprietary drivers which are only available under Windows.
33
34 Most people will say Y or M here, so that they can use serial mice,
35 modems and similar devices connecting to the standard serial ports.
36
37config SERIAL_8250_DEPRECATED_OPTIONS
38 bool "Support 8250_core.* kernel options (DEPRECATED)"
39 depends on SERIAL_8250
40 default y
41 help
42 In 3.7 we renamed 8250 to 8250_core by mistake, so now we have to
43 accept kernel parameters in both forms like 8250_core.nr_uarts=4 and
44 8250.nr_uarts=4. We now renamed the module back to 8250, but if
45 anybody noticed in 3.7 and changed their userspace we still have to
46 keep the 8250_core.* options around until they revert the changes
47 they already did.
48
49 If 8250 is built as a module, this adds 8250_core alias instead.
50
51 If you did not notice yet and/or you have userspace from pre-3.7, it
52 is safe (and recommended) to say N here.
53
54config SERIAL_8250_PNP
55 bool "8250/16550 PNP device support" if EXPERT
56 depends on SERIAL_8250 && PNP
57 default y
58 help
59 This builds standard PNP serial support. You may be able to
60 disable this feature if you only need legacy serial support.
61
62config SERIAL_8250_16550A_VARIANTS
63 bool "Support for variants of the 16550A serial port"
64 depends on SERIAL_8250
65 default !X86
66 help
67 The 8250 driver can probe for many variants of the venerable 16550A
68 serial port. Doing so takes additional time at boot.
69
70 On modern systems, especially those using serial only for a simple
71 console, you can say N here.
72
73config SERIAL_8250_FINTEK
74 bool "Support for Fintek variants"
75 depends on SERIAL_8250
76 help
77 Selecting this option will add support for the RS232 and RS485
78 capabilities of the Fintek F81216A LPC to 4 UART as well similar
79 variants.
80
81 If this option is not selected the device will be configured as a
82 standard 16550A serial port, however the device may not function
83 correctly without this option enabled.
84
85 If unsure, say N.
86
87config SERIAL_8250_CONSOLE
88 bool "Console on 8250/16550 and compatible serial port"
89 depends on SERIAL_8250=y
90 select SERIAL_CORE_CONSOLE
91 select SERIAL_EARLYCON
92 help
93 If you say Y here, it will be possible to use a serial port as the
94 system console (the system console is the device which receives all
95 kernel messages and warnings and which allows logins in single user
96 mode). This could be useful if some terminal or printer is connected
97 to that serial port.
98
99 Even if you say Y here, the currently visible virtual console
100 (/dev/tty0) will still be used as the system console by default, but
101 you can alter that using a kernel command line option such as
102 "console=ttyS1". (Try "man bootparam" or see the documentation of
103 your boot loader (grub or lilo or loadlin) about how to pass options
104 to the kernel at boot time.)
105
106 If you don't have a VGA card installed and you say Y here, the
107 kernel will automatically use the first serial line, /dev/ttyS0, as
108 system console.
109
110 You can set that using a kernel command line option such as
111 "console=uart8250,io,0x3f8,9600n8"
112 "console=uart8250,mmio,0xff5e0000,115200n8".
113 and it will switch to normal serial console when the corresponding
114 port is ready.
115 "earlycon=uart8250,io,0x3f8,9600n8"
116 "earlycon=uart8250,mmio,0xff5e0000,115200n8".
117 it will not only setup early console.
118
119 If unsure, say N.
120
121config SERIAL_8250_PARISC
122 tristate
123 depends on SERIAL_8250 && PARISC
124 default SERIAL_8250
125
126config SERIAL_8250_DMA
127 bool "DMA support for 16550 compatible UART controllers" if EXPERT
128 depends on SERIAL_8250 && DMADEVICES=y
129 default SERIAL_8250
130 help
131 This builds DMA support that can be used with 8250/16650
132 compatible UART controllers that support DMA signaling.
133
134config SERIAL_8250_PCILIB
135 bool
136
137config SERIAL_8250_PCI
138 tristate "8250/16550 PCI device support"
139 depends on SERIAL_8250 && PCI
140 select SERIAL_8250_PCILIB
141 default SERIAL_8250
142 help
143 This builds standard PCI serial support. You may be able to
144 disable this feature if you only need legacy serial support.
145 Saves about 9K.
146 Note that serial ports on NetMos 9835 Multi-I/O cards are handled
147 by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL.
148
149config SERIAL_8250_EXAR
150 tristate "8250/16550 Exar/Commtech PCI/PCIe device support"
151 depends on SERIAL_8250 && PCI
152 default SERIAL_8250
153 help
154 This builds support for XR17C1xx, XR17V3xx and some Commtech
155 422x PCIe serial cards that are not covered by the more generic
156 SERIAL_8250_PCI option.
157
158config SERIAL_8250_HP300
159 tristate
160 depends on SERIAL_8250 && HP300
161 default SERIAL_8250
162
163config SERIAL_8250_CS
164 tristate "8250/16550 PCMCIA device support"
165 depends on PCMCIA && SERIAL_8250
166 help
167 Say Y here to enable support for 16-bit PCMCIA serial devices,
168 including serial port cards, modems, and the modem functions of
169 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
170 credit-card size devices often used with laptops.)
171
172 To compile this driver as a module, choose M here: the
173 module will be called serial_cs.
174
175 If unsure, say N.
176
177config SERIAL_8250_MEN_MCB
178 tristate "MEN MCB UART device support"
179 depends on MCB && SERIAL_8250
180 help
181 This enables support for FPGA based UARTs found on many MEN
182 boards. This driver enables support for the 16z025, 16z057
183 and 16z125 UARTs.
184
185 To compile this driver as a module, chose M here: the
186 module will be called 8250_men_mcb.
187
188
189config SERIAL_8250_NR_UARTS
190 int "Maximum number of 8250/16550 serial ports"
191 depends on SERIAL_8250
192 default "4"
193 help
194 Set this to the number of serial ports you want the driver
195 to support. This includes any ports discovered via ACPI or
196 PCI enumeration and any ports that may be added at run-time
197 via hot-plug, or any ISA multi-port serial cards.
198
199config SERIAL_8250_RUNTIME_UARTS
200 int "Number of 8250/16550 serial ports to register at runtime"
201 depends on SERIAL_8250
202 range 0 SERIAL_8250_NR_UARTS
203 default "4"
204 help
205 Set this to the maximum number of serial ports you want
206 the kernel to register at boot time. This can be overridden
207 with the module parameter "nr_uarts", or boot-time parameter
208 8250.nr_uarts
209
210config SERIAL_8250_EXTENDED
211 bool "Extended 8250/16550 serial driver options"
212 depends on SERIAL_8250
213 help
214 If you wish to use any non-standard features of the standard "dumb"
215 driver, say Y here. This includes HUB6 support, shared serial
216 interrupts, special multiport support, support for more than the
217 four COM 1/2/3/4 boards, etc.
218
219 Note that the answer to this question won't directly affect the
220 kernel: saying N will just cause the configurator to skip all
221 the questions about serial driver options. If unsure, say N.
222
223config SERIAL_8250_MANY_PORTS
224 bool "Support more than 4 legacy serial ports"
225 depends on SERIAL_8250_EXTENDED
226 help
227 Say Y here if you have dumb serial boards other than the four
228 standard COM 1/2/3/4 ports. This may happen if you have an AST
229 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
230 from <https://www.tldp.org/docs.html#howto>), or other custom
231 serial port hardware which acts similar to standard serial port
232 hardware. If you only use the standard COM 1/2/3/4 ports, you can
233 say N here to save some memory. You can also say Y if you have an
234 "intelligent" multiport card such as Digiboards, etc.
235
236#
237# Multi-port serial cards
238#
239
240config SERIAL_8250_FOURPORT
241 tristate "Support Fourport cards"
242 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
243 help
244 Say Y here if you have an AST FourPort serial board.
245
246 To compile this driver as a module, choose M here: the module
247 will be called 8250_fourport.
248
249config SERIAL_8250_ACCENT
250 tristate "Support Accent cards"
251 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
252 help
253 Say Y here if you have an Accent Async serial board.
254
255 To compile this driver as a module, choose M here: the module
256 will be called 8250_accent.
257
258config SERIAL_8250_ASPEED_VUART
259 tristate "Aspeed Virtual UART"
260 depends on SERIAL_8250
261 depends on OF
262 depends on MFD_SYSCON
263 depends on ARCH_ASPEED || COMPILE_TEST
264 select REGMAP
265 help
266 If you want to use the virtual UART (VUART) device on Aspeed
267 BMC platforms, enable this option. This enables the 16550A-
268 compatible device on the local LPC bus, giving a UART device
269 with no physical RS232 connections.
270
271config SERIAL_8250_BOCA
272 tristate "Support Boca cards"
273 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
274 help
275 Say Y here if you have a Boca serial board. Please read the Boca
276 mini-HOWTO, available from <https://www.tldp.org/docs.html#howto>
277
278 To compile this driver as a module, choose M here: the module
279 will be called 8250_boca.
280
281config SERIAL_8250_EXAR_ST16C554
282 tristate "Support Exar ST16C554/554D Quad UART"
283 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
284 help
285 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are
286 tinkering with your Envoy TU301, or have a machine with this UART,
287 say Y here.
288
289 To compile this driver as a module, choose M here: the module
290 will be called 8250_exar_st16c554.
291
292config SERIAL_8250_HUB6
293 tristate "Support Hub6 cards"
294 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
295 help
296 Say Y here if you have a HUB6 serial board.
297
298 To compile this driver as a module, choose M here: the module
299 will be called 8250_hub6.
300
301config SERIAL_8250_PCI1XXXX
302 tristate "Microchip 8250 based serial port"
303 depends on SERIAL_8250 && PCI
304 select SERIAL_8250_PCILIB
305 help
306 Select this option if you have a setup with Microchip PCIe
307 Switch with serial port enabled and wish to enable 8250
308 serial driver for the serial interface. This driver support
309 will ensure to support baud rates upto 1.5Mpbs.
310
311#
312# Misc. options/drivers.
313#
314
315config SERIAL_8250_SHARE_IRQ
316 bool "Support for sharing serial interrupts"
317 depends on SERIAL_8250_EXTENDED
318 help
319 Some serial boards have hardware support which allows multiple dumb
320 serial ports on the same board to share a single IRQ. To enable
321 support for this in the serial driver, say Y here.
322
323config SERIAL_8250_DETECT_IRQ
324 bool "Autodetect IRQ on standard ports (unsafe)"
325 depends on SERIAL_8250_EXTENDED
326 help
327 Say Y here if you want the kernel to try to guess which IRQ
328 to use for your serial port.
329
330 This is considered unsafe; it is far better to configure the IRQ in
331 a boot script using the setserial command.
332
333 If unsure, say N.
334
335config SERIAL_8250_RSA
336 bool "Support RSA serial ports"
337 depends on SERIAL_8250_EXTENDED
338 help
339 Say Y here if you have a IODATA RSA-DV II/S ISA card and
340 would like to use its >115kbps speeds.
341 You will need to provide module parameter "probe_rsa", or boot-time
342 parameter 8250.probe_rsa with I/O addresses of this card then.
343
344 If you don't have such card, or if unsure, say N.
345
346config SERIAL_8250_DWLIB
347 bool
348
349config SERIAL_8250_ACORN
350 tristate "Acorn expansion card serial port support"
351 depends on ARCH_ACORN && SERIAL_8250
352 help
353 If you have an Atomwide Serial card or Serial Port card for an Acorn
354 system, say Y to this option. The driver can handle 1, 2, or 3 port
355 cards. If unsure, say N.
356
357config SERIAL_8250_BCM2835AUX
358 tristate "BCM2835 auxiliar mini UART support"
359 depends on ARCH_BCM2835 || COMPILE_TEST
360 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
361 help
362 Support for the BCM2835 auxiliar mini UART.
363
364 Features and limitations of the UART are
365 Registers are similar to 16650 registers,
366 set bits in the control registers that are unsupported
367 are ignored and read back as 0
368 7/8 bit operation with 1 start and 1 stop bit
369 8 symbols deep fifo for rx and tx
370 SW controlled RTS and SW readable CTS
371 Clock rate derived from system clock
372 Uses 8 times oversampling (compared to 16 times for 16650)
373 Missing break detection (but break generation)
374 Missing framing error detection
375 Missing parity bit
376 Missing receive time-out interrupt
377 Missing DCD, DSR, DTR and RI signals
378
379 If unsure, say N.
380
381config SERIAL_8250_FSL
382 tristate "Freescale 16550 UART support" if COMPILE_TEST && !(PPC || ARM || ARM64)
383 depends on SERIAL_8250
384 default SERIAL_8250 if PPC || ARM || ARM64
385 help
386 Selecting this option enables a workaround for a break-detection
387 erratum for Freescale 16550 UARTs in the 8250 driver. It also
388 enables support for ACPI enumeration.
389
390config SERIAL_8250_DFL
391 tristate "DFL bus driver for Altera 16550 UART"
392 depends on SERIAL_8250 && FPGA_DFL
393 help
394 This option enables support for a Device Feature List (DFL) bus
395 driver for the Altera 16550 UART. One or more Altera 16550 UARTs
396 can be instantiated in a FPGA and then be discovered during
397 enumeration of the DFL bus.
398
399 To compile this driver as a module, chose M here: the
400 module will be called 8250_dfl.
401
402config SERIAL_8250_DW
403 tristate "Support for Synopsys DesignWare 8250 quirks"
404 depends on SERIAL_8250
405 select SERIAL_8250_DWLIB
406 help
407 Selecting this option will enable handling of the extra features
408 present in the Synopsys DesignWare APB UART.
409
410config SERIAL_8250_EM
411 tristate "Support for Emma Mobile integrated serial port"
412 depends on SERIAL_8250 && HAVE_CLK
413 depends on ARCH_RENESAS || COMPILE_TEST
414 help
415 Selecting this option will add support for the integrated serial
416 port hardware found on the Emma Mobile line of processors.
417 If unsure, say N.
418
419config SERIAL_8250_IOC3
420 tristate "SGI IOC3 8250 UART support"
421 depends on SERIAL_8250
422 depends on SGI_MFD_IOC3 || COMPILE_TEST
423 select SERIAL_8250_EXTENDED
424 select SERIAL_8250_SHARE_IRQ
425 help
426 Enable this if you have a SGI Origin or Octane machine. This module
427 provides basic serial support by directly driving the UART chip
428 behind the IOC3 device on those systems. Maximum baud speed is
429 38400bps using this driver.
430
431config SERIAL_8250_RT288X
432 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
433 depends on SERIAL_8250
434 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
435 help
436 Selecting this option will add support for the alternate register
437 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
438 If unsure, say N.
439
440config SERIAL_8250_OMAP
441 tristate "Support for OMAP internal UART (8250 based driver)"
442 depends on SERIAL_8250
443 depends on ARCH_OMAP2PLUS || ARCH_K3 || COMPILE_TEST
444 help
445 If you have a machine based on an Texas Instruments OMAP CPU you
446 can enable its onboard serial ports by enabling this option.
447
448 This driver uses ttyS instead of ttyO.
449
450config SERIAL_8250_OMAP_TTYO_FIXUP
451 bool "Replace ttyO with ttyS"
452 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
453 default y
454 help
455 This option replaces the "console=ttyO" argument with the matching
456 ttyS argument if the user did not specified it on the command line.
457 This ensures that the user can see the kernel output during boot
458 which he wouldn't see otherwise. The getty has still to be configured
459 for ttyS instead of ttyO regardless of this option.
460 This option is intended for people who "automatically" enable this
461 driver without knowing that this driver requires a different console=
462 argument. If you read this, please keep this option disabled and
463 instead update your kernel command line. If you prepare a kernel for a
464 distribution or other kind of larger user base then you probably want
465 to keep this option enabled. Otherwise people might complain about a
466 not booting kernel because the serial console remains silent in case
467 they forgot to update the command line.
468
469config SERIAL_8250_LPC18XX
470 tristate "NXP LPC18xx/43xx serial port support"
471 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
472 default ARCH_LPC18XX
473 help
474 If you have a LPC18xx/43xx based board and want to use the
475 serial port, say Y to this option. If unsure, say Y.
476
477config SERIAL_8250_MT6577
478 tristate "Mediatek serial port support"
479 depends on SERIAL_8250
480 depends on ARCH_MEDIATEK || COMPILE_TEST
481 help
482 If you have a Mediatek based board and want to use the
483 serial port, say Y to this option. If unsure, say N.
484
485config SERIAL_8250_UNIPHIER
486 tristate "Support for UniPhier on-chip UART"
487 depends on SERIAL_8250
488 depends on ARCH_UNIPHIER || COMPILE_TEST
489 help
490 If you have a UniPhier based board and want to use the on-chip
491 serial ports, say Y to this option. If unsure, say N.
492
493config SERIAL_8250_INGENIC
494 tristate "Support for Ingenic SoC serial ports"
495 depends on SERIAL_8250
496 depends on OF_FLATTREE
497 depends on MIPS || COMPILE_TEST
498 help
499 If you have a system using an Ingenic SoC and wish to make use of
500 its UARTs, say Y to this option. If unsure, say N.
501
502config SERIAL_8250_LPSS
503 tristate "Support for serial ports on Intel LPSS platforms"
504 default SERIAL_8250
505 depends on SERIAL_8250 && PCI
506 depends on X86 || COMPILE_TEST
507 select SERIAL_8250_DWLIB
508 select DW_DMAC_CORE if SERIAL_8250_DMA
509 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
510 select RATIONAL
511 help
512 Selecting this option will enable handling of the UART found on
513 various Intel platforms such as:
514 - Intel Baytrail SoC
515 - Intel Braswell SoC
516 - Intel Quark X1000 SoC
517 that are not covered by the more generic SERIAL_8250_PCI option.
518
519config SERIAL_8250_MID
520 tristate "Support for serial ports on Intel MID platforms"
521 default SERIAL_8250
522 depends on SERIAL_8250 && PCI
523 depends on X86 || COMPILE_TEST
524 select HSU_DMA if SERIAL_8250_DMA
525 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
526 select RATIONAL
527 help
528 Selecting this option will enable handling of the UART found on
529 Intel Medfield SOC and various other Intel platforms that is not
530 covered by the more generic SERIAL_8250_PCI option.
531
532config SERIAL_8250_PERICOM
533 tristate "Support for Pericom and Acces I/O serial ports"
534 default SERIAL_8250
535 depends on SERIAL_8250 && PCI
536 help
537 Selecting this option will enable handling of the Pericom and Acces
538 I/O UARTs that are not covered by the more generic SERIAL_8250_PCI
539 option.
540
541config SERIAL_8250_PXA
542 tristate "PXA serial port support"
543 depends on SERIAL_8250
544 depends on ARCH_PXA || ARCH_MMP || COMPILE_TEST
545 help
546 If you have a machine based on an Intel XScale PXA2xx CPU you can
547 enable its onboard serial ports by enabling this option. The option is
548 applicable to both devicetree and legacy boards, and early console is
549 part of its support.
550
551config SERIAL_8250_TEGRA
552 tristate "8250 support for Tegra serial ports"
553 default SERIAL_8250
554 depends on SERIAL_8250
555 depends on ARCH_TEGRA || COMPILE_TEST
556 help
557 Select this option if you have machine with an NVIDIA Tegra SoC and
558 wish to enable 8250 serial driver for the Tegra serial interfaces.
559
560config SERIAL_8250_BCM7271
561 tristate "Broadcom 8250 based serial port"
562 depends on SERIAL_8250 && (ARCH_BRCMSTB || COMPILE_TEST)
563 default ARCH_BRCMSTB
564 help
565 If you have a Broadcom STB based board and want to use the
566 enhanced features of the Broadcom 8250 based serial port,
567 including DMA support and high accuracy BAUD rates, say
568 Y to this option. If unsure, say N.
569
570config SERIAL_OF_PLATFORM
571 tristate "Devicetree based probing for 8250 ports"
572 depends on SERIAL_8250 && OF
573 help
574 This option is used for all 8250 compatible serial ports that
575 are probed through devicetree, including Open Firmware based
576 PowerPC systems and embedded systems on architectures using the
577 flattened device tree format.
1# SPDX-License-Identifier: GPL-2.0
2#
3# The 8250/16550 serial drivers. You shouldn't be in this list unless
4# you somehow have an implicit or explicit dependency on SERIAL_8250.
5#
6
7config SERIAL_8250
8 tristate "8250/16550 and compatible serial support"
9 depends on !S390
10 select SERIAL_CORE
11 select SERIAL_MCTRL_GPIO if GPIOLIB
12 help
13 This selects whether you want to include the driver for the standard
14 serial ports. The standard answer is Y. People who might say N
15 here are those that are setting up dedicated Ethernet WWW/FTP
16 servers, or users that have one of the various bus mice instead of a
17 serial mouse and don't intend to use their machine's standard serial
18 port for anything.
19
20 To compile this driver as a module, choose M here: the
21 module will be called 8250.
22 [WARNING: Do not compile this driver as a module if you are using
23 non-standard serial ports, since the configuration information will
24 be lost when the driver is unloaded. This limitation may be lifted
25 in the future.]
26
27 BTW1: If you have a mouseman serial mouse which is not recognized by
28 the X window system, try running gpm first.
29
30 BTW2: If you intend to use a software modem (also called Winmodem)
31 under Linux, forget it. These modems are crippled and require
32 proprietary drivers which are only available under Windows.
33
34 Most people will say Y or M here, so that they can use serial mice,
35 modems and similar devices connecting to the standard serial ports.
36
37config SERIAL_8250_DEPRECATED_OPTIONS
38 bool "Support 8250_core.* kernel options (DEPRECATED)"
39 depends on SERIAL_8250
40 default y
41 help
42 In 3.7 we renamed 8250 to 8250_core by mistake, so now we have to
43 accept kernel parameters in both forms like 8250_core.nr_uarts=4 and
44 8250.nr_uarts=4. We now renamed the module back to 8250, but if
45 anybody noticed in 3.7 and changed their userspace we still have to
46 keep the 8250_core.* options around until they revert the changes
47 they already did.
48
49 If 8250 is built as a module, this adds 8250_core alias instead.
50
51 If you did not notice yet and/or you have userspace from pre-3.7, it
52 is safe (and recommended) to say N here.
53
54config SERIAL_8250_PNP
55 bool "8250/16550 PNP device support" if EXPERT
56 depends on SERIAL_8250 && PNP
57 default y
58 help
59 This builds standard PNP serial support. You may be able to
60 disable this feature if you only need legacy serial support.
61
62config SERIAL_8250_16550A_VARIANTS
63 bool "Support for variants of the 16550A serial port"
64 depends on SERIAL_8250
65 default !X86
66 help
67 The 8250 driver can probe for many variants of the venerable 16550A
68 serial port. Doing so takes additional time at boot.
69
70 On modern systems, especially those using serial only for a simple
71 console, you can say N here.
72
73config SERIAL_8250_FINTEK
74 bool "Support for Fintek F81216A LPC to 4 UART RS485 API"
75 depends on SERIAL_8250
76 help
77 Selecting this option will add support for the RS485 capabilities
78 of the Fintek F81216A LPC to 4 UART.
79
80 If this option is not selected the device will be configured as a
81 standard 16550A serial port.
82
83 If unsure, say N.
84
85config SERIAL_8250_CONSOLE
86 bool "Console on 8250/16550 and compatible serial port"
87 depends on SERIAL_8250=y
88 select SERIAL_CORE_CONSOLE
89 select SERIAL_EARLYCON
90 help
91 If you say Y here, it will be possible to use a serial port as the
92 system console (the system console is the device which receives all
93 kernel messages and warnings and which allows logins in single user
94 mode). This could be useful if some terminal or printer is connected
95 to that serial port.
96
97 Even if you say Y here, the currently visible virtual console
98 (/dev/tty0) will still be used as the system console by default, but
99 you can alter that using a kernel command line option such as
100 "console=ttyS1". (Try "man bootparam" or see the documentation of
101 your boot loader (grub or lilo or loadlin) about how to pass options
102 to the kernel at boot time.)
103
104 If you don't have a VGA card installed and you say Y here, the
105 kernel will automatically use the first serial line, /dev/ttyS0, as
106 system console.
107
108 You can set that using a kernel command line option such as
109 "console=uart8250,io,0x3f8,9600n8"
110 "console=uart8250,mmio,0xff5e0000,115200n8".
111 and it will switch to normal serial console when the corresponding
112 port is ready.
113 "earlycon=uart8250,io,0x3f8,9600n8"
114 "earlycon=uart8250,mmio,0xff5e0000,115200n8".
115 it will not only setup early console.
116
117 If unsure, say N.
118
119config SERIAL_8250_PARISC
120 tristate
121 depends on SERIAL_8250 && PARISC
122 default SERIAL_8250
123
124config SERIAL_8250_DMA
125 bool "DMA support for 16550 compatible UART controllers" if EXPERT
126 depends on SERIAL_8250 && DMADEVICES=y
127 default SERIAL_8250
128 help
129 This builds DMA support that can be used with 8250/16650
130 compatible UART controllers that support DMA signaling.
131
132config SERIAL_8250_PCI
133 tristate "8250/16550 PCI device support"
134 depends on SERIAL_8250 && PCI
135 default SERIAL_8250
136 help
137 This builds standard PCI serial support. You may be able to
138 disable this feature if you only need legacy serial support.
139 Saves about 9K.
140 Note that serial ports on NetMos 9835 Multi-I/O cards are handled
141 by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL.
142
143config SERIAL_8250_EXAR
144 tristate "8250/16550 Exar/Commtech PCI/PCIe device support"
145 depends on SERIAL_8250_PCI
146 default SERIAL_8250
147 help
148 This builds support for XR17C1xx, XR17V3xx and some Commtech
149 422x PCIe serial cards that are not covered by the more generic
150 SERIAL_8250_PCI option.
151
152config SERIAL_8250_HP300
153 tristate
154 depends on SERIAL_8250 && HP300
155 default SERIAL_8250
156
157config SERIAL_8250_CS
158 tristate "8250/16550 PCMCIA device support"
159 depends on PCMCIA && SERIAL_8250
160 help
161 Say Y here to enable support for 16-bit PCMCIA serial devices,
162 including serial port cards, modems, and the modem functions of
163 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
164 credit-card size devices often used with laptops.)
165
166 To compile this driver as a module, choose M here: the
167 module will be called serial_cs.
168
169 If unsure, say N.
170
171config SERIAL_8250_MEN_MCB
172 tristate "MEN MCB UART device support"
173 depends on MCB && SERIAL_8250
174 help
175 This enables support for FPGA based UARTs found on many MEN
176 boards. This driver enables support for the 16z025, 16z057
177 and 16z125 UARTs.
178
179 To compile this driver as a module, chose M here: the
180 module will be called 8250_men_mcb.
181
182
183config SERIAL_8250_NR_UARTS
184 int "Maximum number of 8250/16550 serial ports"
185 depends on SERIAL_8250
186 default "4"
187 help
188 Set this to the number of serial ports you want the driver
189 to support. This includes any ports discovered via ACPI or
190 PCI enumeration and any ports that may be added at run-time
191 via hot-plug, or any ISA multi-port serial cards.
192
193config SERIAL_8250_RUNTIME_UARTS
194 int "Number of 8250/16550 serial ports to register at runtime"
195 depends on SERIAL_8250
196 range 0 SERIAL_8250_NR_UARTS
197 default "4"
198 help
199 Set this to the maximum number of serial ports you want
200 the kernel to register at boot time. This can be overridden
201 with the module parameter "nr_uarts", or boot-time parameter
202 8250.nr_uarts
203
204config SERIAL_8250_EXTENDED
205 bool "Extended 8250/16550 serial driver options"
206 depends on SERIAL_8250
207 help
208 If you wish to use any non-standard features of the standard "dumb"
209 driver, say Y here. This includes HUB6 support, shared serial
210 interrupts, special multiport support, support for more than the
211 four COM 1/2/3/4 boards, etc.
212
213 Note that the answer to this question won't directly affect the
214 kernel: saying N will just cause the configurator to skip all
215 the questions about serial driver options. If unsure, say N.
216
217config SERIAL_8250_MANY_PORTS
218 bool "Support more than 4 legacy serial ports"
219 depends on SERIAL_8250_EXTENDED && !IA64
220 help
221 Say Y here if you have dumb serial boards other than the four
222 standard COM 1/2/3/4 ports. This may happen if you have an AST
223 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
224 from <https://www.tldp.org/docs.html#howto>), or other custom
225 serial port hardware which acts similar to standard serial port
226 hardware. If you only use the standard COM 1/2/3/4 ports, you can
227 say N here to save some memory. You can also say Y if you have an
228 "intelligent" multiport card such as Digiboards, etc.
229
230#
231# Multi-port serial cards
232#
233
234config SERIAL_8250_FOURPORT
235 tristate "Support Fourport cards"
236 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
237 help
238 Say Y here if you have an AST FourPort serial board.
239
240 To compile this driver as a module, choose M here: the module
241 will be called 8250_fourport.
242
243config SERIAL_8250_ACCENT
244 tristate "Support Accent cards"
245 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
246 help
247 Say Y here if you have an Accent Async serial board.
248
249 To compile this driver as a module, choose M here: the module
250 will be called 8250_accent.
251
252config SERIAL_8250_ASPEED_VUART
253 tristate "Aspeed Virtual UART"
254 depends on SERIAL_8250
255 depends on OF
256 depends on REGMAP && MFD_SYSCON
257 depends on ARCH_ASPEED || COMPILE_TEST
258 help
259 If you want to use the virtual UART (VUART) device on Aspeed
260 BMC platforms, enable this option. This enables the 16550A-
261 compatible device on the local LPC bus, giving a UART device
262 with no physical RS232 connections.
263
264config SERIAL_8250_BOCA
265 tristate "Support Boca cards"
266 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
267 help
268 Say Y here if you have a Boca serial board. Please read the Boca
269 mini-HOWTO, available from <https://www.tldp.org/docs.html#howto>
270
271 To compile this driver as a module, choose M here: the module
272 will be called 8250_boca.
273
274config SERIAL_8250_EXAR_ST16C554
275 tristate "Support Exar ST16C554/554D Quad UART"
276 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
277 help
278 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are
279 tinkering with your Envoy TU301, or have a machine with this UART,
280 say Y here.
281
282 To compile this driver as a module, choose M here: the module
283 will be called 8250_exar_st16c554.
284
285config SERIAL_8250_HUB6
286 tristate "Support Hub6 cards"
287 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
288 help
289 Say Y here if you have a HUB6 serial board.
290
291 To compile this driver as a module, choose M here: the module
292 will be called 8250_hub6.
293
294#
295# Misc. options/drivers.
296#
297
298config SERIAL_8250_SHARE_IRQ
299 bool "Support for sharing serial interrupts"
300 depends on SERIAL_8250_EXTENDED
301 help
302 Some serial boards have hardware support which allows multiple dumb
303 serial ports on the same board to share a single IRQ. To enable
304 support for this in the serial driver, say Y here.
305
306config SERIAL_8250_DETECT_IRQ
307 bool "Autodetect IRQ on standard ports (unsafe)"
308 depends on SERIAL_8250_EXTENDED
309 help
310 Say Y here if you want the kernel to try to guess which IRQ
311 to use for your serial port.
312
313 This is considered unsafe; it is far better to configure the IRQ in
314 a boot script using the setserial command.
315
316 If unsure, say N.
317
318config SERIAL_8250_RSA
319 bool "Support RSA serial ports"
320 depends on SERIAL_8250_EXTENDED
321 help
322 Say Y here if you have a IODATA RSA-DV II/S ISA card and
323 would like to use its >115kbps speeds.
324 You will need to provide module parameter "probe_rsa", or boot-time
325 parameter 8250.probe_rsa with I/O addresses of this card then.
326
327 If you don't have such card, or if unsure, say N.
328
329config SERIAL_8250_DWLIB
330 bool
331
332config SERIAL_8250_ACORN
333 tristate "Acorn expansion card serial port support"
334 depends on ARCH_ACORN && SERIAL_8250
335 help
336 If you have an Atomwide Serial card or Serial Port card for an Acorn
337 system, say Y to this option. The driver can handle 1, 2, or 3 port
338 cards. If unsure, say N.
339
340config SERIAL_8250_BCM2835AUX
341 tristate "BCM2835 auxiliar mini UART support"
342 depends on ARCH_BCM2835 || COMPILE_TEST
343 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
344 help
345 Support for the BCM2835 auxiliar mini UART.
346
347 Features and limitations of the UART are
348 Registers are similar to 16650 registers,
349 set bits in the control registers that are unsupported
350 are ignored and read back as 0
351 7/8 bit operation with 1 start and 1 stop bit
352 8 symbols deep fifo for rx and tx
353 SW controlled RTS and SW readable CTS
354 Clock rate derived from system clock
355 Uses 8 times oversampling (compared to 16 times for 16650)
356 Missing break detection (but break generation)
357 Missing framing error detection
358 Missing parity bit
359 Missing receive time-out interrupt
360 Missing DCD, DSR, DTR and RI signals
361
362 If unsure, say N.
363
364config SERIAL_8250_FSL
365 bool "Freescale 16550 UART support" if COMPILE_TEST && !(PPC || ARM || ARM64)
366 depends on SERIAL_8250_CONSOLE
367 default PPC || ARM || ARM64
368 help
369 Selecting this option enables a workaround for a break-detection
370 erratum for Freescale 16550 UARTs in the 8250 driver. It also
371 enables support for ACPI enumeration.
372
373config SERIAL_8250_DW
374 tristate "Support for Synopsys DesignWare 8250 quirks"
375 depends on SERIAL_8250
376 select SERIAL_8250_DWLIB
377 help
378 Selecting this option will enable handling of the extra features
379 present in the Synopsys DesignWare APB UART.
380
381config SERIAL_8250_EM
382 tristate "Support for Emma Mobile integrated serial port"
383 depends on SERIAL_8250 && HAVE_CLK
384 depends on ARCH_RENESAS || COMPILE_TEST
385 help
386 Selecting this option will add support for the integrated serial
387 port hardware found on the Emma Mobile line of processors.
388 If unsure, say N.
389
390config SERIAL_8250_IOC3
391 tristate "SGI IOC3 8250 UART support"
392 depends on SERIAL_8250
393 depends on SGI_MFD_IOC3 || COMPILE_TEST
394 select SERIAL_8250_EXTENDED
395 select SERIAL_8250_SHARE_IRQ
396 help
397 Enable this if you have a SGI Origin or Octane machine. This module
398 provides basic serial support by directly driving the UART chip
399 behind the IOC3 device on those systems. Maximum baud speed is
400 38400bps using this driver.
401
402config SERIAL_8250_RT288X
403 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
404 depends on SERIAL_8250
405 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
406 help
407 Selecting this option will add support for the alternate register
408 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
409 If unsure, say N.
410
411config SERIAL_8250_OMAP
412 tristate "Support for OMAP internal UART (8250 based driver)"
413 depends on SERIAL_8250
414 depends on ARCH_OMAP2PLUS || ARCH_K3 || COMPILE_TEST
415 help
416 If you have a machine based on an Texas Instruments OMAP CPU you
417 can enable its onboard serial ports by enabling this option.
418
419 This driver uses ttyS instead of ttyO.
420
421config SERIAL_8250_OMAP_TTYO_FIXUP
422 bool "Replace ttyO with ttyS"
423 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
424 default y
425 help
426 This option replaces the "console=ttyO" argument with the matching
427 ttyS argument if the user did not specified it on the command line.
428 This ensures that the user can see the kernel output during boot
429 which he wouldn't see otherwise. The getty has still to be configured
430 for ttyS instead of ttyO regardless of this option.
431 This option is intended for people who "automatically" enable this
432 driver without knowing that this driver requires a different console=
433 argument. If you read this, please keep this option disabled and
434 instead update your kernel command line. If you prepare a kernel for a
435 distribution or other kind of larger user base then you probably want
436 to keep this option enabled. Otherwise people might complain about a
437 not booting kernel because the serial console remains silent in case
438 they forgot to update the command line.
439
440config SERIAL_8250_LPC18XX
441 tristate "NXP LPC18xx/43xx serial port support"
442 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
443 default ARCH_LPC18XX
444 help
445 If you have a LPC18xx/43xx based board and want to use the
446 serial port, say Y to this option. If unsure, say Y.
447
448config SERIAL_8250_MT6577
449 tristate "Mediatek serial port support"
450 depends on SERIAL_8250
451 depends on ARCH_MEDIATEK || COMPILE_TEST
452 help
453 If you have a Mediatek based board and want to use the
454 serial port, say Y to this option. If unsure, say N.
455
456config SERIAL_8250_UNIPHIER
457 tristate "Support for UniPhier on-chip UART"
458 depends on SERIAL_8250
459 depends on ARCH_UNIPHIER || COMPILE_TEST
460 help
461 If you have a UniPhier based board and want to use the on-chip
462 serial ports, say Y to this option. If unsure, say N.
463
464config SERIAL_8250_INGENIC
465 tristate "Support for Ingenic SoC serial ports"
466 depends on SERIAL_8250
467 depends on OF_FLATTREE
468 depends on MIPS || COMPILE_TEST
469 help
470 If you have a system using an Ingenic SoC and wish to make use of
471 its UARTs, say Y to this option. If unsure, say N.
472
473config SERIAL_8250_LPSS
474 tristate "Support for serial ports on Intel LPSS platforms"
475 default SERIAL_8250
476 depends on SERIAL_8250 && PCI
477 depends on X86 || COMPILE_TEST
478 select SERIAL_8250_DWLIB
479 select DW_DMAC_CORE if SERIAL_8250_DMA
480 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
481 select RATIONAL
482 help
483 Selecting this option will enable handling of the UART found on
484 various Intel platforms such as:
485 - Intel Baytrail SoC
486 - Intel Braswell SoC
487 - Intel Quark X1000 SoC
488 that are not covered by the more generic SERIAL_8250_PCI option.
489
490config SERIAL_8250_MID
491 tristate "Support for serial ports on Intel MID platforms"
492 default SERIAL_8250
493 depends on SERIAL_8250 && PCI
494 depends on X86 || COMPILE_TEST
495 select HSU_DMA if SERIAL_8250_DMA
496 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
497 select RATIONAL
498 help
499 Selecting this option will enable handling of the UART found on
500 Intel Medfield SOC and various other Intel platforms that is not
501 covered by the more generic SERIAL_8250_PCI option.
502
503config SERIAL_8250_PERICOM
504 tristate "Support for Pericom and Acces I/O serial ports"
505 default SERIAL_8250
506 depends on SERIAL_8250 && PCI
507 help
508 Selecting this option will enable handling of the Pericom and Acces
509 I/O UARTs that are not covered by the more generic SERIAL_8250_PCI
510 option.
511
512config SERIAL_8250_PXA
513 tristate "PXA serial port support"
514 depends on SERIAL_8250
515 depends on ARCH_PXA || ARCH_MMP || COMPILE_TEST
516 help
517 If you have a machine based on an Intel XScale PXA2xx CPU you can
518 enable its onboard serial ports by enabling this option. The option is
519 applicable to both devicetree and legacy boards, and early console is
520 part of its support.
521
522config SERIAL_8250_TEGRA
523 tristate "8250 support for Tegra serial ports"
524 default SERIAL_8250
525 depends on SERIAL_8250
526 depends on ARCH_TEGRA || COMPILE_TEST
527 help
528 Select this option if you have machine with an NVIDIA Tegra SoC and
529 wish to enable 8250 serial driver for the Tegra serial interfaces.
530
531config SERIAL_8250_BCM7271
532 tristate "Broadcom 8250 based serial port"
533 depends on SERIAL_8250 && (ARCH_BRCMSTB || COMPILE_TEST)
534 default ARCH_BRCMSTB
535 help
536 If you have a Broadcom STB based board and want to use the
537 enhanced features of the Broadcom 8250 based serial port,
538 including DMA support and high accuracy BAUD rates, say
539 Y to this option. If unsure, say N.
540
541config SERIAL_OF_PLATFORM
542 tristate "Devicetree based probing for 8250 ports"
543 depends on SERIAL_8250 && OF
544 help
545 This option is used for all 8250 compatible serial ports that
546 are probed through devicetree, including Open Firmware based
547 PowerPC systems and embedded systems on architectures using the
548 flattened device tree format.