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.
7 tristate "8250/16550 and compatible serial support"
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.)
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
25 BTW1: If you have a mouseman serial mouse which is not recognized by
26 the X window system, try running gpm first.
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.
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.
35 config SERIAL_8250_DEPRECATED_OPTIONS
36 bool "Support 8250_core.* kernel options (DEPRECATED)"
37 depends on SERIAL_8250
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
47 If 8250 is built as a module, this adds 8250_core alias instead.
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.
52 config SERIAL_8250_PNP
53 bool "8250/16550 PNP device support" if EXPERT
54 depends on SERIAL_8250 && PNP
57 This builds standard PNP serial support. You may be able to
58 disable this feature if you only need legacy serial support.
60 config SERIAL_8250_FINTEK
61 bool "Support for Fintek F81216A LPC to 4 UART RS485 API"
62 depends on SERIAL_8250
64 Selecting this option will add support for the RS485 capabilities
65 of the Fintek F81216A LPC to 4 UART.
67 If this option is not selected the device will be configured as a
68 standard 16550A serial port.
72 config 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
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
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.)
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
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
100 "earlycon=uart8250,io,0x3f8,9600n8"
101 "earlycon=uart8250,mmio,0xff5e0000,115200n8".
102 it will not only setup early console.
106 config SERIAL_8250_GSC
108 depends on SERIAL_8250 && GSC
111 config SERIAL_8250_DMA
112 bool "DMA support for 16550 compatible UART controllers" if EXPERT
113 depends on SERIAL_8250 && DMADEVICES=y
116 This builds DMA support that can be used with 8250/16650
117 compatible UART controllers that support DMA signaling.
119 config SERIAL_8250_PCI
120 tristate "8250/16550 PCI device support"
121 depends on SERIAL_8250 && PCI
124 This builds standard PCI serial support. You may be able to
125 disable this feature if you only need legacy serial support.
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.
130 config SERIAL_8250_EXAR
131 tristate "8250/16550 Exar/Commtech PCI/PCIe device support"
132 depends on SERIAL_8250_PCI
135 This builds support for XR17C1xx, XR17V3xx and some Commtech
136 422x PCIe serial cards that are not covered by the more generic
137 SERIAL_8250_PCI option.
139 config SERIAL_8250_HP300
141 depends on SERIAL_8250 && HP300
144 config SERIAL_8250_CS
145 tristate "8250/16550 PCMCIA device support"
146 depends on PCMCIA && SERIAL_8250
148 Say Y here to enable support for 16-bit PCMCIA serial devices,
149 including serial port cards, modems, and the modem functions of
150 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
151 credit-card size devices often used with laptops.)
153 To compile this driver as a module, choose M here: the
154 module will be called serial_cs.
158 config SERIAL_8250_MEN_MCB
159 tristate "MEN Z125 UART device support"
160 depends on MCB && SERIAL_8250
162 This enables support for FPGA based UARTs found on many MEN
163 boards. This driver enables support for the Z125 UARTs.
165 To compile this driver as a module, chose M here: the
166 module will be called 8250_men_mcb.
169 config SERIAL_8250_NR_UARTS
170 int "Maximum number of 8250/16550 serial ports"
171 depends on SERIAL_8250
174 Set this to the number of serial ports you want the driver
175 to support. This includes any ports discovered via ACPI or
176 PCI enumeration and any ports that may be added at run-time
177 via hot-plug, or any ISA multi-port serial cards.
179 config SERIAL_8250_RUNTIME_UARTS
180 int "Number of 8250/16550 serial ports to register at runtime"
181 depends on SERIAL_8250
182 range 0 SERIAL_8250_NR_UARTS
185 Set this to the maximum number of serial ports you want
186 the kernel to register at boot time. This can be overridden
187 with the module parameter "nr_uarts", or boot-time parameter
190 config SERIAL_8250_EXTENDED
191 bool "Extended 8250/16550 serial driver options"
192 depends on SERIAL_8250
194 If you wish to use any non-standard features of the standard "dumb"
195 driver, say Y here. This includes HUB6 support, shared serial
196 interrupts, special multiport support, support for more than the
197 four COM 1/2/3/4 boards, etc.
199 Note that the answer to this question won't directly affect the
200 kernel: saying N will just cause the configurator to skip all
201 the questions about serial driver options. If unsure, say N.
203 config SERIAL_8250_MANY_PORTS
204 bool "Support more than 4 legacy serial ports"
205 depends on SERIAL_8250_EXTENDED && !IA64
207 Say Y here if you have dumb serial boards other than the four
208 standard COM 1/2/3/4 ports. This may happen if you have an AST
209 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
210 from <http://www.tldp.org/docs.html#howto>), or other custom
211 serial port hardware which acts similar to standard serial port
212 hardware. If you only use the standard COM 1/2/3/4 ports, you can
213 say N here to save some memory. You can also say Y if you have an
214 "intelligent" multiport card such as Cyclades, Digiboards, etc.
217 # Multi-port serial cards
220 config SERIAL_8250_FOURPORT
221 tristate "Support Fourport cards"
222 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
224 Say Y here if you have an AST FourPort serial board.
226 To compile this driver as a module, choose M here: the module
227 will be called 8250_fourport.
229 config SERIAL_8250_ACCENT
230 tristate "Support Accent cards"
231 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
233 Say Y here if you have an Accent Async serial board.
235 To compile this driver as a module, choose M here: the module
236 will be called 8250_accent.
238 config SERIAL_8250_ASPEED_VUART
239 tristate "Aspeed Virtual UART"
240 depends on SERIAL_8250
243 If you want to use the virtual UART (VUART) device on Aspeed
244 BMC platforms, enable this option. This enables the 16550A-
245 compatible device on the local LPC bus, giving a UART device
246 with no physical RS232 connections.
248 config SERIAL_8250_BOCA
249 tristate "Support Boca cards"
250 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
252 Say Y here if you have a Boca serial board. Please read the Boca
253 mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
255 To compile this driver as a module, choose M here: the module
256 will be called 8250_boca.
258 config SERIAL_8250_EXAR_ST16C554
259 tristate "Support Exar ST16C554/554D Quad UART"
260 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
262 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are
263 tinkering with your Envoy TU301, or have a machine with this UART,
266 To compile this driver as a module, choose M here: the module
267 will be called 8250_exar_st16c554.
269 config SERIAL_8250_HUB6
270 tristate "Support Hub6 cards"
271 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
273 Say Y here if you have a HUB6 serial board.
275 To compile this driver as a module, choose M here: the module
276 will be called 8250_hub6.
279 # Misc. options/drivers.
282 config SERIAL_8250_SHARE_IRQ
283 bool "Support for sharing serial interrupts"
284 depends on SERIAL_8250_EXTENDED
286 Some serial boards have hardware support which allows multiple dumb
287 serial ports on the same board to share a single IRQ. To enable
288 support for this in the serial driver, say Y here.
290 config SERIAL_8250_DETECT_IRQ
291 bool "Autodetect IRQ on standard ports (unsafe)"
292 depends on SERIAL_8250_EXTENDED
294 Say Y here if you want the kernel to try to guess which IRQ
295 to use for your serial port.
297 This is considered unsafe; it is far better to configure the IRQ in
298 a boot script using the setserial command.
302 config SERIAL_8250_RSA
303 bool "Support RSA serial ports"
304 depends on SERIAL_8250_EXTENDED
306 Say Y here if you have a IODATA RSA-DV II/S ISA card and
307 would like to use its >115kbps speeds.
308 You will need to provide module parameter "probe_rsa", or boot-time
309 parameter 8250.probe_rsa with I/O addresses of this card then.
311 If you don't have such card, or if unsure, say N.
313 config SERIAL_8250_ACORN
314 tristate "Acorn expansion card serial port support"
315 depends on ARCH_ACORN && SERIAL_8250
317 If you have an Atomwide Serial card or Serial Port card for an Acorn
318 system, say Y to this option. The driver can handle 1, 2, or 3 port
319 cards. If unsure, say N.
321 config SERIAL_8250_BCM2835AUX
322 tristate "BCM2835 auxiliar mini UART support"
323 depends on ARCH_BCM2835 || COMPILE_TEST
324 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
326 Support for the BCM2835 auxiliar mini UART.
328 Features and limitations of the UART are
329 Registers are similar to 16650 registers,
330 set bits in the control registers that are unsupported
331 are ignored and read back as 0
332 7/8 bit operation with 1 start and 1 stop bit
333 8 symbols deep fifo for rx and tx
334 SW controlled RTS and SW readable CTS
335 Clock rate derived from system clock
336 Uses 8 times oversampling (compared to 16 times for 16650)
337 Missing break detection (but break generation)
338 Missing framing error detection
340 Missing receive time-out interrupt
341 Missing DCD, DSR, DTR and RI signals
345 config SERIAL_8250_FSL
347 depends on SERIAL_8250_CONSOLE
348 default PPC || ARM || ARM64
350 config SERIAL_8250_DW
351 tristate "Support for Synopsys DesignWare 8250 quirks"
352 depends on SERIAL_8250
354 Selecting this option will enable handling of the extra features
355 present in the Synopsys DesignWare APB UART.
357 config SERIAL_8250_EM
358 tristate "Support for Emma Mobile integrated serial port"
359 depends on SERIAL_8250 && ARM && HAVE_CLK
361 Selecting this option will add support for the integrated serial
362 port hardware found on the Emma Mobile line of processors.
365 config SERIAL_8250_RT288X
366 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
367 depends on SERIAL_8250
368 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
370 Selecting this option will add support for the alternate register
371 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
374 config SERIAL_8250_OMAP
375 tristate "Support for OMAP internal UART (8250 based driver)"
376 depends on SERIAL_8250 && ARCH_OMAP2PLUS
378 If you have a machine based on an Texas Instruments OMAP CPU you
379 can enable its onboard serial ports by enabling this option.
381 This driver uses ttyS instead of ttyO.
383 config SERIAL_8250_OMAP_TTYO_FIXUP
384 bool "Replace ttyO with ttyS"
385 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
388 This option replaces the "console=ttyO" argument with the matching
389 ttyS argument if the user did not specified it on the command line.
390 This ensures that the user can see the kernel output during boot
391 which he wouldn't see otherwise. The getty has still to be configured
392 for ttyS instead of ttyO regardless of this option.
393 This option is intended for people who "automatically" enable this
394 driver without knowing that this driver requires a different console=
395 argument. If you read this, please keep this option disabled and
396 instead update your kernel command line. If you prepare a kernel for a
397 distribution or other kind of larger user base then you probably want
398 to keep this option enabled. Otherwise people might complain about a
399 not booting kernel because the serial console remains silent in case
400 they forgot to update the command line.
402 config SERIAL_8250_LPC18XX
403 tristate "NXP LPC18xx/43xx serial port support"
404 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
407 If you have a LPC18xx/43xx based board and want to use the
408 serial port, say Y to this option. If unsure, say Y.
410 config SERIAL_8250_MT6577
411 tristate "Mediatek serial port support"
412 depends on SERIAL_8250 && ARCH_MEDIATEK
414 If you have a Mediatek based board and want to use the
415 serial port, say Y to this option. If unsure, say N.
417 config SERIAL_8250_UNIPHIER
418 tristate "Support for UniPhier on-chip UART"
419 depends on SERIAL_8250
420 depends on ARCH_UNIPHIER || COMPILE_TEST
422 If you have a UniPhier based board and want to use the on-chip
423 serial ports, say Y to this option. If unsure, say N.
425 config SERIAL_8250_INGENIC
426 tristate "Support for Ingenic SoC serial ports"
427 depends on SERIAL_8250
428 depends on OF_FLATTREE
429 depends on MIPS || COMPILE_TEST
431 If you have a system using an Ingenic SoC and wish to make use of
432 its UARTs, say Y to this option. If unsure, say N.
434 config SERIAL_8250_LPSS
435 tristate "Support for serial ports on Intel LPSS platforms"
437 depends on SERIAL_8250 && PCI
438 depends on X86 || COMPILE_TEST
439 select DW_DMAC_CORE if SERIAL_8250_DMA
440 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
443 Selecting this option will enable handling of the extra features
444 present on the UART found on various Intel platforms such as:
447 - Intel Quark X1000 SoC
449 config SERIAL_8250_MID
450 tristate "Support for serial ports on Intel MID platforms"
452 depends on SERIAL_8250 && PCI
453 depends on X86 || COMPILE_TEST
454 select HSU_DMA if SERIAL_8250_DMA
455 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
458 Selecting this option will enable handling of the extra features
459 present on the UART found on Intel Medfield SOC and various other
462 config SERIAL_8250_MOXA
463 tristate "MOXA SmartIO MUE support"
464 depends on SERIAL_8250 && PCI
466 Say Y here if you have a Moxa SmartIO MUE multiport serial card.
469 This driver can also be built as a module. The module will be called
470 8250_moxa. If you want to do that, say M here.
472 config SERIAL_8250_PXA
473 tristate "PXA serial port support"
474 depends on SERIAL_8250
475 depends on ARCH_PXA || ARCH_MMP
477 If you have a machine based on an Intel XScale PXA2xx CPU you can
478 enable its onboard serial ports by enabling this option. The option is
479 applicable to both devicetree and legacy boards, and early console is
482 config SERIAL_OF_PLATFORM
483 tristate "Devicetree based probing for 8250 ports"
484 depends on SERIAL_8250 && OF
486 This option is used for all 8250 compatible serial ports that
487 are probed through devicetree, including Open Firmware based
488 PowerPC systems and embedded systems on architectures using the
489 flattened device tree format.