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_NR_UARTS
159 int "Maximum number of 8250/16550 serial ports"
160 depends on SERIAL_8250
163 Set this to the number of serial ports you want the driver
164 to support. This includes any ports discovered via ACPI or
165 PCI enumeration and any ports that may be added at run-time
166 via hot-plug, or any ISA multi-port serial cards.
168 config SERIAL_8250_RUNTIME_UARTS
169 int "Number of 8250/16550 serial ports to register at runtime"
170 depends on SERIAL_8250
171 range 0 SERIAL_8250_NR_UARTS
174 Set this to the maximum number of serial ports you want
175 the kernel to register at boot time. This can be overridden
176 with the module parameter "nr_uarts", or boot-time parameter
179 config SERIAL_8250_EXTENDED
180 bool "Extended 8250/16550 serial driver options"
181 depends on SERIAL_8250
183 If you wish to use any non-standard features of the standard "dumb"
184 driver, say Y here. This includes HUB6 support, shared serial
185 interrupts, special multiport support, support for more than the
186 four COM 1/2/3/4 boards, etc.
188 Note that the answer to this question won't directly affect the
189 kernel: saying N will just cause the configurator to skip all
190 the questions about serial driver options. If unsure, say N.
192 config SERIAL_8250_MANY_PORTS
193 bool "Support more than 4 legacy serial ports"
194 depends on SERIAL_8250_EXTENDED && !IA64
196 Say Y here if you have dumb serial boards other than the four
197 standard COM 1/2/3/4 ports. This may happen if you have an AST
198 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
199 from <http://www.tldp.org/docs.html#howto>), or other custom
200 serial port hardware which acts similar to standard serial port
201 hardware. If you only use the standard COM 1/2/3/4 ports, you can
202 say N here to save some memory. You can also say Y if you have an
203 "intelligent" multiport card such as Cyclades, Digiboards, etc.
206 # Multi-port serial cards
209 config SERIAL_8250_FOURPORT
210 tristate "Support Fourport cards"
211 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
213 Say Y here if you have an AST FourPort serial board.
215 To compile this driver as a module, choose M here: the module
216 will be called 8250_fourport.
218 config SERIAL_8250_ACCENT
219 tristate "Support Accent cards"
220 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
222 Say Y here if you have an Accent Async serial board.
224 To compile this driver as a module, choose M here: the module
225 will be called 8250_accent.
227 config SERIAL_8250_BOCA
228 tristate "Support Boca cards"
229 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
231 Say Y here if you have a Boca serial board. Please read the Boca
232 mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
234 To compile this driver as a module, choose M here: the module
235 will be called 8250_boca.
237 config SERIAL_8250_EXAR_ST16C554
238 tristate "Support Exar ST16C554/554D Quad UART"
239 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
241 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are
242 tinkering with your Envoy TU301, or have a machine with this UART,
245 To compile this driver as a module, choose M here: the module
246 will be called 8250_exar_st16c554.
248 config SERIAL_8250_HUB6
249 tristate "Support Hub6 cards"
250 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
252 Say Y here if you have a HUB6 serial board.
254 To compile this driver as a module, choose M here: the module
255 will be called 8250_hub6.
258 # Misc. options/drivers.
261 config SERIAL_8250_SHARE_IRQ
262 bool "Support for sharing serial interrupts"
263 depends on SERIAL_8250_EXTENDED
265 Some serial boards have hardware support which allows multiple dumb
266 serial ports on the same board to share a single IRQ. To enable
267 support for this in the serial driver, say Y here.
269 config SERIAL_8250_DETECT_IRQ
270 bool "Autodetect IRQ on standard ports (unsafe)"
271 depends on SERIAL_8250_EXTENDED
273 Say Y here if you want the kernel to try to guess which IRQ
274 to use for your serial port.
276 This is considered unsafe; it is far better to configure the IRQ in
277 a boot script using the setserial command.
281 config SERIAL_8250_RSA
282 bool "Support RSA serial ports"
283 depends on SERIAL_8250_EXTENDED
285 Say Y here if you have a IODATA RSA-DV II/S ISA card and
286 would like to use its >115kbps speeds.
287 You will need to provide module parameter "probe_rsa", or boot-time
288 parameter 8250.probe_rsa with I/O addresses of this card then.
290 If you don't have such card, or if unsure, say N.
292 config SERIAL_8250_ACORN
293 tristate "Acorn expansion card serial port support"
294 depends on ARCH_ACORN && SERIAL_8250
296 If you have an Atomwide Serial card or Serial Port card for an Acorn
297 system, say Y to this option. The driver can handle 1, 2, or 3 port
298 cards. If unsure, say N.
300 config SERIAL_8250_BCM2835AUX
301 tristate "BCM2835 auxiliar mini UART support"
302 depends on ARCH_BCM2835 || COMPILE_TEST
303 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
305 Support for the BCM2835 auxiliar mini UART.
307 Features and limitations of the UART are
308 Registers are similar to 16650 registers,
309 set bits in the control registers that are unsupported
310 are ignored and read back as 0
311 7/8 bit operation with 1 start and 1 stop bit
312 8 symbols deep fifo for rx and tx
313 SW controlled RTS and SW readable CTS
314 Clock rate derived from system clock
315 Uses 8 times oversampling (compared to 16 times for 16650)
316 Missing break detection (but break generation)
317 Missing framing error detection
319 Missing receive time-out interrupt
320 Missing DCD, DSR, DTR and RI signals
324 config SERIAL_8250_FSL
326 depends on SERIAL_8250_CONSOLE
327 default PPC || ARM || ARM64
329 config SERIAL_8250_DW
330 tristate "Support for Synopsys DesignWare 8250 quirks"
331 depends on SERIAL_8250
333 Selecting this option will enable handling of the extra features
334 present in the Synopsys DesignWare APB UART.
336 config SERIAL_8250_EM
337 tristate "Support for Emma Mobile integrated serial port"
338 depends on SERIAL_8250 && ARM && HAVE_CLK
340 Selecting this option will add support for the integrated serial
341 port hardware found on the Emma Mobile line of processors.
344 config SERIAL_8250_RT288X
345 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
346 depends on SERIAL_8250
347 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
349 Selecting this option will add support for the alternate register
350 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
353 config SERIAL_8250_OMAP
354 tristate "Support for OMAP internal UART (8250 based driver)"
355 depends on SERIAL_8250 && ARCH_OMAP2PLUS
357 If you have a machine based on an Texas Instruments OMAP CPU you
358 can enable its onboard serial ports by enabling this option.
360 This driver uses ttyS instead of ttyO.
362 config SERIAL_8250_OMAP_TTYO_FIXUP
363 bool "Replace ttyO with ttyS"
364 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
367 This option replaces the "console=ttyO" argument with the matching
368 ttyS argument if the user did not specified it on the command line.
369 This ensures that the user can see the kernel output during boot
370 which he wouldn't see otherwise. The getty has still to be configured
371 for ttyS instead of ttyO regardless of this option.
372 This option is intended for people who "automatically" enable this
373 driver without knowing that this driver requires a different console=
374 argument. If you read this, please keep this option disabled and
375 instead update your kernel command line. If you prepare a kernel for a
376 distribution or other kind of larger user base then you probably want
377 to keep this option enabled. Otherwise people might complain about a
378 not booting kernel because the serial console remains silent in case
379 they forgot to update the command line.
381 config SERIAL_8250_LPC18XX
382 tristate "NXP LPC18xx/43xx serial port support"
383 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
386 If you have a LPC18xx/43xx based board and want to use the
387 serial port, say Y to this option. If unsure, say Y.
389 config SERIAL_8250_MT6577
390 tristate "Mediatek serial port support"
391 depends on SERIAL_8250 && ARCH_MEDIATEK
393 If you have a Mediatek based board and want to use the
394 serial port, say Y to this option. If unsure, say N.
396 config SERIAL_8250_UNIPHIER
397 tristate "Support for UniPhier on-chip UART"
398 depends on SERIAL_8250
399 depends on ARCH_UNIPHIER || COMPILE_TEST
401 If you have a UniPhier based board and want to use the on-chip
402 serial ports, say Y to this option. If unsure, say N.
404 config SERIAL_8250_INGENIC
405 tristate "Support for Ingenic SoC serial ports"
406 depends on SERIAL_8250
407 depends on OF_FLATTREE
408 depends on MIPS || COMPILE_TEST
410 If you have a system using an Ingenic SoC and wish to make use of
411 its UARTs, say Y to this option. If unsure, say N.
413 config SERIAL_8250_LPSS
414 tristate "Support for serial ports on Intel LPSS platforms"
416 depends on SERIAL_8250 && PCI
417 depends on X86 || COMPILE_TEST
418 select DW_DMAC_CORE if SERIAL_8250_DMA
419 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
422 Selecting this option will enable handling of the extra features
423 present on the UART found on various Intel platforms such as:
426 - Intel Quark X1000 SoC
428 config SERIAL_8250_MID
429 tristate "Support for serial ports on Intel MID platforms"
431 depends on SERIAL_8250 && PCI
432 depends on X86 || COMPILE_TEST
433 select HSU_DMA if SERIAL_8250_DMA
434 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
437 Selecting this option will enable handling of the extra features
438 present on the UART found on Intel Medfield SOC and various other
441 config SERIAL_8250_MOXA
442 tristate "MOXA SmartIO MUE support"
443 depends on SERIAL_8250 && PCI
445 Say Y here if you have a Moxa SmartIO MUE multiport serial card.
448 This driver can also be built as a module. The module will be called
449 8250_moxa. If you want to do that, say M here.
451 config SERIAL_8250_PXA
452 tristate "PXA serial port support"
453 depends on SERIAL_8250
454 depends on ARCH_PXA || ARCH_MMP
456 If you have a machine based on an Intel XScale PXA2xx CPU you can
457 enable its onboard serial ports by enabling this option. The option is
458 applicable to both devicetree and legacy boards, and early console is
461 config SERIAL_OF_PLATFORM
462 tristate "Devicetree based probing for 8250 ports"
463 depends on SERIAL_8250 && OF
465 This option is used for all 8250 compatible serial ports that
466 are probed through devicetree, including Open Firmware based
467 PowerPC systems and embedded systems on architectures using the
468 flattened device tree format.