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"
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.)
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
26 BTW1: If you have a mouseman serial mouse which is not recognized by
27 the X window system, try running gpm first.
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.
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.
36 config SERIAL_8250_DEPRECATED_OPTIONS
37 bool "Support 8250_core.* kernel options (DEPRECATED)"
38 depends on SERIAL_8250
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
48 If 8250 is built as a module, this adds 8250_core alias instead.
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.
53 config SERIAL_8250_PNP
54 bool "8250/16550 PNP device support" if EXPERT
55 depends on SERIAL_8250 && PNP
58 This builds standard PNP serial support. You may be able to
59 disable this feature if you only need legacy serial support.
61 config SERIAL_8250_FINTEK
62 bool "Support for Fintek F81216A LPC to 4 UART RS485 API"
63 depends on SERIAL_8250
65 Selecting this option will add support for the RS485 capabilities
66 of the Fintek F81216A LPC to 4 UART.
68 If this option is not selected the device will be configured as a
69 standard 16550A serial port.
73 config 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
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
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.)
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
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
101 "earlycon=uart8250,io,0x3f8,9600n8"
102 "earlycon=uart8250,mmio,0xff5e0000,115200n8".
103 it will not only setup early console.
107 config SERIAL_8250_GSC
109 depends on SERIAL_8250 && GSC
112 config SERIAL_8250_DMA
113 bool "DMA support for 16550 compatible UART controllers" if EXPERT
114 depends on SERIAL_8250 && DMADEVICES=y
117 This builds DMA support that can be used with 8250/16650
118 compatible UART controllers that support DMA signaling.
120 config SERIAL_8250_PCI
121 tristate "8250/16550 PCI device support"
122 depends on SERIAL_8250 && PCI
125 This builds standard PCI serial support. You may be able to
126 disable this feature if you only need legacy serial support.
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.
131 config SERIAL_8250_EXAR
132 tristate "8250/16550 Exar/Commtech PCI/PCIe device support"
133 depends on SERIAL_8250_PCI
136 This builds support for XR17C1xx, XR17V3xx and some Commtech
137 422x PCIe serial cards that are not covered by the more generic
138 SERIAL_8250_PCI option.
140 config SERIAL_8250_HP300
142 depends on SERIAL_8250 && HP300
145 config SERIAL_8250_CS
146 tristate "8250/16550 PCMCIA device support"
147 depends on PCMCIA && SERIAL_8250
149 Say Y here to enable support for 16-bit PCMCIA serial devices,
150 including serial port cards, modems, and the modem functions of
151 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
152 credit-card size devices often used with laptops.)
154 To compile this driver as a module, choose M here: the
155 module will be called serial_cs.
159 config SERIAL_8250_MEN_MCB
160 tristate "MEN Z125 UART device support"
161 depends on MCB && SERIAL_8250
163 This enables support for FPGA based UARTs found on many MEN
164 boards. This driver enables support for the Z125 UARTs.
166 To compile this driver as a module, chose M here: the
167 module will be called 8250_men_mcb.
170 config SERIAL_8250_NR_UARTS
171 int "Maximum number of 8250/16550 serial ports"
172 depends on SERIAL_8250
175 Set this to the number of serial ports you want the driver
176 to support. This includes any ports discovered via ACPI or
177 PCI enumeration and any ports that may be added at run-time
178 via hot-plug, or any ISA multi-port serial cards.
180 config SERIAL_8250_RUNTIME_UARTS
181 int "Number of 8250/16550 serial ports to register at runtime"
182 depends on SERIAL_8250
183 range 0 SERIAL_8250_NR_UARTS
186 Set this to the maximum number of serial ports you want
187 the kernel to register at boot time. This can be overridden
188 with the module parameter "nr_uarts", or boot-time parameter
191 config SERIAL_8250_EXTENDED
192 bool "Extended 8250/16550 serial driver options"
193 depends on SERIAL_8250
195 If you wish to use any non-standard features of the standard "dumb"
196 driver, say Y here. This includes HUB6 support, shared serial
197 interrupts, special multiport support, support for more than the
198 four COM 1/2/3/4 boards, etc.
200 Note that the answer to this question won't directly affect the
201 kernel: saying N will just cause the configurator to skip all
202 the questions about serial driver options. If unsure, say N.
204 config SERIAL_8250_MANY_PORTS
205 bool "Support more than 4 legacy serial ports"
206 depends on SERIAL_8250_EXTENDED && !IA64
208 Say Y here if you have dumb serial boards other than the four
209 standard COM 1/2/3/4 ports. This may happen if you have an AST
210 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
211 from <http://www.tldp.org/docs.html#howto>), or other custom
212 serial port hardware which acts similar to standard serial port
213 hardware. If you only use the standard COM 1/2/3/4 ports, you can
214 say N here to save some memory. You can also say Y if you have an
215 "intelligent" multiport card such as Cyclades, Digiboards, etc.
218 # Multi-port serial cards
221 config SERIAL_8250_FOURPORT
222 tristate "Support Fourport cards"
223 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
225 Say Y here if you have an AST FourPort serial board.
227 To compile this driver as a module, choose M here: the module
228 will be called 8250_fourport.
230 config SERIAL_8250_ACCENT
231 tristate "Support Accent cards"
232 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
234 Say Y here if you have an Accent Async serial board.
236 To compile this driver as a module, choose M here: the module
237 will be called 8250_accent.
239 config SERIAL_8250_ASPEED_VUART
240 tristate "Aspeed Virtual UART"
241 depends on SERIAL_8250
244 If you want to use the virtual UART (VUART) device on Aspeed
245 BMC platforms, enable this option. This enables the 16550A-
246 compatible device on the local LPC bus, giving a UART device
247 with no physical RS232 connections.
249 config SERIAL_8250_BOCA
250 tristate "Support Boca cards"
251 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
253 Say Y here if you have a Boca serial board. Please read the Boca
254 mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
256 To compile this driver as a module, choose M here: the module
257 will be called 8250_boca.
259 config SERIAL_8250_EXAR_ST16C554
260 tristate "Support Exar ST16C554/554D Quad UART"
261 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
263 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are
264 tinkering with your Envoy TU301, or have a machine with this UART,
267 To compile this driver as a module, choose M here: the module
268 will be called 8250_exar_st16c554.
270 config SERIAL_8250_HUB6
271 tristate "Support Hub6 cards"
272 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
274 Say Y here if you have a HUB6 serial board.
276 To compile this driver as a module, choose M here: the module
277 will be called 8250_hub6.
280 # Misc. options/drivers.
283 config SERIAL_8250_SHARE_IRQ
284 bool "Support for sharing serial interrupts"
285 depends on SERIAL_8250_EXTENDED
287 Some serial boards have hardware support which allows multiple dumb
288 serial ports on the same board to share a single IRQ. To enable
289 support for this in the serial driver, say Y here.
291 config SERIAL_8250_DETECT_IRQ
292 bool "Autodetect IRQ on standard ports (unsafe)"
293 depends on SERIAL_8250_EXTENDED
295 Say Y here if you want the kernel to try to guess which IRQ
296 to use for your serial port.
298 This is considered unsafe; it is far better to configure the IRQ in
299 a boot script using the setserial command.
303 config SERIAL_8250_RSA
304 bool "Support RSA serial ports"
305 depends on SERIAL_8250_EXTENDED
307 Say Y here if you have a IODATA RSA-DV II/S ISA card and
308 would like to use its >115kbps speeds.
309 You will need to provide module parameter "probe_rsa", or boot-time
310 parameter 8250.probe_rsa with I/O addresses of this card then.
312 If you don't have such card, or if unsure, say N.
314 config SERIAL_8250_ACORN
315 tristate "Acorn expansion card serial port support"
316 depends on ARCH_ACORN && SERIAL_8250
318 If you have an Atomwide Serial card or Serial Port card for an Acorn
319 system, say Y to this option. The driver can handle 1, 2, or 3 port
320 cards. If unsure, say N.
322 config SERIAL_8250_BCM2835AUX
323 tristate "BCM2835 auxiliar mini UART support"
324 depends on ARCH_BCM2835 || COMPILE_TEST
325 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
327 Support for the BCM2835 auxiliar mini UART.
329 Features and limitations of the UART are
330 Registers are similar to 16650 registers,
331 set bits in the control registers that are unsupported
332 are ignored and read back as 0
333 7/8 bit operation with 1 start and 1 stop bit
334 8 symbols deep fifo for rx and tx
335 SW controlled RTS and SW readable CTS
336 Clock rate derived from system clock
337 Uses 8 times oversampling (compared to 16 times for 16650)
338 Missing break detection (but break generation)
339 Missing framing error detection
341 Missing receive time-out interrupt
342 Missing DCD, DSR, DTR and RI signals
346 config SERIAL_8250_FSL
348 depends on SERIAL_8250_CONSOLE
349 default PPC || ARM || ARM64
351 config SERIAL_8250_DW
352 tristate "Support for Synopsys DesignWare 8250 quirks"
353 depends on SERIAL_8250
355 Selecting this option will enable handling of the extra features
356 present in the Synopsys DesignWare APB UART.
358 config SERIAL_8250_EM
359 tristate "Support for Emma Mobile integrated serial port"
360 depends on SERIAL_8250 && ARM && HAVE_CLK
362 Selecting this option will add support for the integrated serial
363 port hardware found on the Emma Mobile line of processors.
366 config SERIAL_8250_RT288X
367 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
368 depends on SERIAL_8250
369 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
371 Selecting this option will add support for the alternate register
372 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
375 config SERIAL_8250_OMAP
376 tristate "Support for OMAP internal UART (8250 based driver)"
377 depends on SERIAL_8250 && ARCH_OMAP2PLUS
379 If you have a machine based on an Texas Instruments OMAP CPU you
380 can enable its onboard serial ports by enabling this option.
382 This driver uses ttyS instead of ttyO.
384 config SERIAL_8250_OMAP_TTYO_FIXUP
385 bool "Replace ttyO with ttyS"
386 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
389 This option replaces the "console=ttyO" argument with the matching
390 ttyS argument if the user did not specified it on the command line.
391 This ensures that the user can see the kernel output during boot
392 which he wouldn't see otherwise. The getty has still to be configured
393 for ttyS instead of ttyO regardless of this option.
394 This option is intended for people who "automatically" enable this
395 driver without knowing that this driver requires a different console=
396 argument. If you read this, please keep this option disabled and
397 instead update your kernel command line. If you prepare a kernel for a
398 distribution or other kind of larger user base then you probably want
399 to keep this option enabled. Otherwise people might complain about a
400 not booting kernel because the serial console remains silent in case
401 they forgot to update the command line.
403 config SERIAL_8250_LPC18XX
404 tristate "NXP LPC18xx/43xx serial port support"
405 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
408 If you have a LPC18xx/43xx based board and want to use the
409 serial port, say Y to this option. If unsure, say Y.
411 config SERIAL_8250_MT6577
412 tristate "Mediatek serial port support"
413 depends on SERIAL_8250 && ARCH_MEDIATEK
415 If you have a Mediatek based board and want to use the
416 serial port, say Y to this option. If unsure, say N.
418 config SERIAL_8250_UNIPHIER
419 tristate "Support for UniPhier on-chip UART"
420 depends on SERIAL_8250
421 depends on ARCH_UNIPHIER || COMPILE_TEST
423 If you have a UniPhier based board and want to use the on-chip
424 serial ports, say Y to this option. If unsure, say N.
426 config SERIAL_8250_INGENIC
427 tristate "Support for Ingenic SoC serial ports"
428 depends on SERIAL_8250
429 depends on OF_FLATTREE
430 depends on MIPS || COMPILE_TEST
432 If you have a system using an Ingenic SoC and wish to make use of
433 its UARTs, say Y to this option. If unsure, say N.
435 config SERIAL_8250_LPSS
436 tristate "Support for serial ports on Intel LPSS platforms"
438 depends on SERIAL_8250 && PCI
439 depends on X86 || COMPILE_TEST
440 select DW_DMAC_CORE if SERIAL_8250_DMA
441 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
444 Selecting this option will enable handling of the extra features
445 present on the UART found on various Intel platforms such as:
448 - Intel Quark X1000 SoC
450 config SERIAL_8250_MID
451 tristate "Support for serial ports on Intel MID platforms"
453 depends on SERIAL_8250 && PCI
454 depends on X86 || COMPILE_TEST
455 select HSU_DMA if SERIAL_8250_DMA
456 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
459 Selecting this option will enable handling of the extra features
460 present on the UART found on Intel Medfield SOC and various other
463 config SERIAL_8250_MOXA
464 tristate "MOXA SmartIO MUE support"
465 depends on SERIAL_8250 && PCI
467 Say Y here if you have a Moxa SmartIO MUE multiport serial card.
470 This driver can also be built as a module. The module will be called
471 8250_moxa. If you want to do that, say M here.
473 config SERIAL_8250_PXA
474 tristate "PXA serial port support"
475 depends on SERIAL_8250
476 depends on ARCH_PXA || ARCH_MMP
478 If you have a machine based on an Intel XScale PXA2xx CPU you can
479 enable its onboard serial ports by enabling this option. The option is
480 applicable to both devicetree and legacy boards, and early console is
483 config SERIAL_OF_PLATFORM
484 tristate "Devicetree based probing for 8250 ports"
485 depends on SERIAL_8250 && OF
487 This option is used for all 8250 compatible serial ports that
488 are probed through devicetree, including Open Firmware based
489 PowerPC systems and embedded systems on architectures using the
490 flattened device tree format.