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 PCI device support"
132 depends on SERIAL_8250_PCI
135 config SERIAL_8250_HP300
137 depends on SERIAL_8250 && HP300
140 config SERIAL_8250_CS
141 tristate "8250/16550 PCMCIA device support"
142 depends on PCMCIA && SERIAL_8250
144 Say Y here to enable support for 16-bit PCMCIA serial devices,
145 including serial port cards, modems, and the modem functions of
146 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
147 credit-card size devices often used with laptops.)
149 To compile this driver as a module, choose M here: the
150 module will be called serial_cs.
154 config SERIAL_8250_NR_UARTS
155 int "Maximum number of 8250/16550 serial ports"
156 depends on SERIAL_8250
159 Set this to the number of serial ports you want the driver
160 to support. This includes any ports discovered via ACPI or
161 PCI enumeration and any ports that may be added at run-time
162 via hot-plug, or any ISA multi-port serial cards.
164 config SERIAL_8250_RUNTIME_UARTS
165 int "Number of 8250/16550 serial ports to register at runtime"
166 depends on SERIAL_8250
167 range 0 SERIAL_8250_NR_UARTS
170 Set this to the maximum number of serial ports you want
171 the kernel to register at boot time. This can be overridden
172 with the module parameter "nr_uarts", or boot-time parameter
175 config SERIAL_8250_EXTENDED
176 bool "Extended 8250/16550 serial driver options"
177 depends on SERIAL_8250
179 If you wish to use any non-standard features of the standard "dumb"
180 driver, say Y here. This includes HUB6 support, shared serial
181 interrupts, special multiport support, support for more than the
182 four COM 1/2/3/4 boards, etc.
184 Note that the answer to this question won't directly affect the
185 kernel: saying N will just cause the configurator to skip all
186 the questions about serial driver options. If unsure, say N.
188 config SERIAL_8250_MANY_PORTS
189 bool "Support more than 4 legacy serial ports"
190 depends on SERIAL_8250_EXTENDED && !IA64
192 Say Y here if you have dumb serial boards other than the four
193 standard COM 1/2/3/4 ports. This may happen if you have an AST
194 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
195 from <http://www.tldp.org/docs.html#howto>), or other custom
196 serial port hardware which acts similar to standard serial port
197 hardware. If you only use the standard COM 1/2/3/4 ports, you can
198 say N here to save some memory. You can also say Y if you have an
199 "intelligent" multiport card such as Cyclades, Digiboards, etc.
202 # Multi-port serial cards
205 config SERIAL_8250_FOURPORT
206 tristate "Support Fourport cards"
207 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
209 Say Y here if you have an AST FourPort serial board.
211 To compile this driver as a module, choose M here: the module
212 will be called 8250_fourport.
214 config SERIAL_8250_ACCENT
215 tristate "Support Accent cards"
216 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
218 Say Y here if you have an Accent Async serial board.
220 To compile this driver as a module, choose M here: the module
221 will be called 8250_accent.
223 config SERIAL_8250_BOCA
224 tristate "Support Boca cards"
225 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
227 Say Y here if you have a Boca serial board. Please read the Boca
228 mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
230 To compile this driver as a module, choose M here: the module
231 will be called 8250_boca.
233 config SERIAL_8250_EXAR_ST16C554
234 tristate "Support Exar ST16C554/554D Quad UART"
235 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
237 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are
238 tinkering with your Envoy TU301, or have a machine with this UART,
241 To compile this driver as a module, choose M here: the module
242 will be called 8250_exar_st16c554.
244 config SERIAL_8250_HUB6
245 tristate "Support Hub6 cards"
246 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
248 Say Y here if you have a HUB6 serial board.
250 To compile this driver as a module, choose M here: the module
251 will be called 8250_hub6.
254 # Misc. options/drivers.
257 config SERIAL_8250_SHARE_IRQ
258 bool "Support for sharing serial interrupts"
259 depends on SERIAL_8250_EXTENDED
261 Some serial boards have hardware support which allows multiple dumb
262 serial ports on the same board to share a single IRQ. To enable
263 support for this in the serial driver, say Y here.
265 config SERIAL_8250_DETECT_IRQ
266 bool "Autodetect IRQ on standard ports (unsafe)"
267 depends on SERIAL_8250_EXTENDED
269 Say Y here if you want the kernel to try to guess which IRQ
270 to use for your serial port.
272 This is considered unsafe; it is far better to configure the IRQ in
273 a boot script using the setserial command.
277 config SERIAL_8250_RSA
278 bool "Support RSA serial ports"
279 depends on SERIAL_8250_EXTENDED
281 Say Y here if you have a IODATA RSA-DV II/S ISA card and
282 would like to use its >115kbps speeds.
283 You will need to provide module parameter "probe_rsa", or boot-time
284 parameter 8250.probe_rsa with I/O addresses of this card then.
286 If you don't have such card, or if unsure, say N.
288 config SERIAL_8250_ACORN
289 tristate "Acorn expansion card serial port support"
290 depends on ARCH_ACORN && SERIAL_8250
292 If you have an Atomwide Serial card or Serial Port card for an Acorn
293 system, say Y to this option. The driver can handle 1, 2, or 3 port
294 cards. If unsure, say N.
296 config SERIAL_8250_BCM2835AUX
297 tristate "BCM2835 auxiliar mini UART support"
298 depends on ARCH_BCM2835 || COMPILE_TEST
299 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
301 Support for the BCM2835 auxiliar mini UART.
303 Features and limitations of the UART are
304 Registers are similar to 16650 registers,
305 set bits in the control registers that are unsupported
306 are ignored and read back as 0
307 7/8 bit operation with 1 start and 1 stop bit
308 8 symbols deep fifo for rx and tx
309 SW controlled RTS and SW readable CTS
310 Clock rate derived from system clock
311 Uses 8 times oversampling (compared to 16 times for 16650)
312 Missing break detection (but break generation)
313 Missing framing error detection
315 Missing receive time-out interrupt
316 Missing DCD, DSR, DTR and RI signals
320 config SERIAL_8250_FSL
322 depends on SERIAL_8250_CONSOLE
323 default PPC || ARM || ARM64
325 config SERIAL_8250_DW
326 tristate "Support for Synopsys DesignWare 8250 quirks"
327 depends on SERIAL_8250
329 Selecting this option will enable handling of the extra features
330 present in the Synopsys DesignWare APB UART.
332 config SERIAL_8250_EM
333 tristate "Support for Emma Mobile integrated serial port"
334 depends on SERIAL_8250 && ARM && HAVE_CLK
336 Selecting this option will add support for the integrated serial
337 port hardware found on the Emma Mobile line of processors.
340 config SERIAL_8250_RT288X
341 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
342 depends on SERIAL_8250
343 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
345 Selecting this option will add support for the alternate register
346 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
349 config SERIAL_8250_OMAP
350 tristate "Support for OMAP internal UART (8250 based driver)"
351 depends on SERIAL_8250 && ARCH_OMAP2PLUS
353 If you have a machine based on an Texas Instruments OMAP CPU you
354 can enable its onboard serial ports by enabling this option.
356 This driver uses ttyS instead of ttyO.
358 config SERIAL_8250_OMAP_TTYO_FIXUP
359 bool "Replace ttyO with ttyS"
360 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
363 This option replaces the "console=ttyO" argument with the matching
364 ttyS argument if the user did not specified it on the command line.
365 This ensures that the user can see the kernel output during boot
366 which he wouldn't see otherwise. The getty has still to be configured
367 for ttyS instead of ttyO regardless of this option.
368 This option is intended for people who "automatically" enable this
369 driver without knowing that this driver requires a different console=
370 argument. If you read this, please keep this option disabled and
371 instead update your kernel command line. If you prepare a kernel for a
372 distribution or other kind of larger user base then you probably want
373 to keep this option enabled. Otherwise people might complain about a
374 not booting kernel because the serial console remains silent in case
375 they forgot to update the command line.
377 config SERIAL_8250_LPC18XX
378 tristate "NXP LPC18xx/43xx serial port support"
379 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
382 If you have a LPC18xx/43xx based board and want to use the
383 serial port, say Y to this option. If unsure, say Y.
385 config SERIAL_8250_MT6577
386 tristate "Mediatek serial port support"
387 depends on SERIAL_8250 && ARCH_MEDIATEK
389 If you have a Mediatek based board and want to use the
390 serial port, say Y to this option. If unsure, say N.
392 config SERIAL_8250_UNIPHIER
393 tristate "Support for UniPhier on-chip UART"
394 depends on SERIAL_8250
395 depends on ARCH_UNIPHIER || COMPILE_TEST
397 If you have a UniPhier based board and want to use the on-chip
398 serial ports, say Y to this option. If unsure, say N.
400 config SERIAL_8250_INGENIC
401 tristate "Support for Ingenic SoC serial ports"
402 depends on SERIAL_8250
403 depends on OF_FLATTREE
404 depends on MIPS || COMPILE_TEST
406 If you have a system using an Ingenic SoC and wish to make use of
407 its UARTs, say Y to this option. If unsure, say N.
409 config SERIAL_8250_LPSS
410 tristate "Support for serial ports on Intel LPSS platforms"
412 depends on SERIAL_8250 && PCI
413 depends on X86 || COMPILE_TEST
414 select DW_DMAC_CORE if SERIAL_8250_DMA
415 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
418 Selecting this option will enable handling of the extra features
419 present on the UART found on various Intel platforms such as:
422 - Intel Quark X1000 SoC
424 config SERIAL_8250_MID
425 tristate "Support for serial ports on Intel MID platforms"
427 depends on SERIAL_8250 && PCI
428 depends on X86 || COMPILE_TEST
429 select HSU_DMA if SERIAL_8250_DMA
430 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
433 Selecting this option will enable handling of the extra features
434 present on the UART found on Intel Medfield SOC and various other
437 config SERIAL_8250_MOXA
438 tristate "MOXA SmartIO MUE support"
439 depends on SERIAL_8250 && PCI
441 Say Y here if you have a Moxa SmartIO MUE multiport serial card.
444 This driver can also be built as a module. The module will be called
445 8250_moxa. If you want to do that, say M here.
447 config SERIAL_8250_PXA
448 tristate "PXA serial port support"
449 depends on SERIAL_8250
450 depends on ARCH_PXA || ARCH_MMP
452 If you have a machine based on an Intel XScale PXA2xx CPU you can
453 enable its onboard serial ports by enabling this option. The option is
454 applicable to both devicetree and legacy boards, and early console is
457 config SERIAL_OF_PLATFORM
458 tristate "Devicetree based probing for 8250 ports"
459 depends on SERIAL_8250 && OF
461 This option is used for all 8250 compatible serial ports that
462 are probed through devicetree, including Open Firmware based
463 PowerPC systems and embedded systems on architectures using the
464 flattened device tree format.