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" if EXPERT
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_HP300
132 depends on SERIAL_8250 && HP300
135 config SERIAL_8250_CS
136 tristate "8250/16550 PCMCIA device support"
137 depends on PCMCIA && SERIAL_8250
139 Say Y here to enable support for 16-bit PCMCIA serial devices,
140 including serial port cards, modems, and the modem functions of
141 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
142 credit-card size devices often used with laptops.)
144 To compile this driver as a module, choose M here: the
145 module will be called serial_cs.
149 config SERIAL_8250_NR_UARTS
150 int "Maximum number of 8250/16550 serial ports"
151 depends on SERIAL_8250
154 Set this to the number of serial ports you want the driver
155 to support. This includes any ports discovered via ACPI or
156 PCI enumeration and any ports that may be added at run-time
157 via hot-plug, or any ISA multi-port serial cards.
159 config SERIAL_8250_RUNTIME_UARTS
160 int "Number of 8250/16550 serial ports to register at runtime"
161 depends on SERIAL_8250
162 range 0 SERIAL_8250_NR_UARTS
165 Set this to the maximum number of serial ports you want
166 the kernel to register at boot time. This can be overridden
167 with the module parameter "nr_uarts", or boot-time parameter
170 config SERIAL_8250_EXTENDED
171 bool "Extended 8250/16550 serial driver options"
172 depends on SERIAL_8250
174 If you wish to use any non-standard features of the standard "dumb"
175 driver, say Y here. This includes HUB6 support, shared serial
176 interrupts, special multiport support, support for more than the
177 four COM 1/2/3/4 boards, etc.
179 Note that the answer to this question won't directly affect the
180 kernel: saying N will just cause the configurator to skip all
181 the questions about serial driver options. If unsure, say N.
183 config SERIAL_8250_MANY_PORTS
184 bool "Support more than 4 legacy serial ports"
185 depends on SERIAL_8250_EXTENDED && !IA64
187 Say Y here if you have dumb serial boards other than the four
188 standard COM 1/2/3/4 ports. This may happen if you have an AST
189 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
190 from <http://www.tldp.org/docs.html#howto>), or other custom
191 serial port hardware which acts similar to standard serial port
192 hardware. If you only use the standard COM 1/2/3/4 ports, you can
193 say N here to save some memory. You can also say Y if you have an
194 "intelligent" multiport card such as Cyclades, Digiboards, etc.
197 # Multi-port serial cards
200 config SERIAL_8250_FOURPORT
201 tristate "Support Fourport cards"
202 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
204 Say Y here if you have an AST FourPort serial board.
206 To compile this driver as a module, choose M here: the module
207 will be called 8250_fourport.
209 config SERIAL_8250_ACCENT
210 tristate "Support Accent cards"
211 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
213 Say Y here if you have an Accent Async serial board.
215 To compile this driver as a module, choose M here: the module
216 will be called 8250_accent.
218 config SERIAL_8250_BOCA
219 tristate "Support Boca cards"
220 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
222 Say Y here if you have a Boca serial board. Please read the Boca
223 mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
225 To compile this driver as a module, choose M here: the module
226 will be called 8250_boca.
228 config SERIAL_8250_EXAR_ST16C554
229 tristate "Support Exar ST16C554/554D Quad UART"
230 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
232 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are
233 tinkering with your Envoy TU301, or have a machine with this UART,
236 To compile this driver as a module, choose M here: the module
237 will be called 8250_exar_st16c554.
239 config SERIAL_8250_HUB6
240 tristate "Support Hub6 cards"
241 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
243 Say Y here if you have a HUB6 serial board.
245 To compile this driver as a module, choose M here: the module
246 will be called 8250_hub6.
249 # Misc. options/drivers.
252 config SERIAL_8250_SHARE_IRQ
253 bool "Support for sharing serial interrupts"
254 depends on SERIAL_8250_EXTENDED
256 Some serial boards have hardware support which allows multiple dumb
257 serial ports on the same board to share a single IRQ. To enable
258 support for this in the serial driver, say Y here.
260 config SERIAL_8250_DETECT_IRQ
261 bool "Autodetect IRQ on standard ports (unsafe)"
262 depends on SERIAL_8250_EXTENDED
264 Say Y here if you want the kernel to try to guess which IRQ
265 to use for your serial port.
267 This is considered unsafe; it is far better to configure the IRQ in
268 a boot script using the setserial command.
272 config SERIAL_8250_RSA
273 bool "Support RSA serial ports"
274 depends on SERIAL_8250_EXTENDED
276 Say Y here if you have a IODATA RSA-DV II/S ISA card and
277 would like to use its >115kbps speeds.
278 You will need to provide module parameter "probe_rsa", or boot-time
279 parameter 8250.probe_rsa with I/O addresses of this card then.
281 If you don't have such card, or if unsure, say N.
283 config SERIAL_8250_ACORN
284 tristate "Acorn expansion card serial port support"
285 depends on ARCH_ACORN && SERIAL_8250
287 If you have an Atomwide Serial card or Serial Port card for an Acorn
288 system, say Y to this option. The driver can handle 1, 2, or 3 port
289 cards. If unsure, say N.
291 config SERIAL_8250_BCM2835AUX
292 tristate "BCM2835 auxiliar mini UART support"
293 depends on ARCH_BCM2835 || COMPILE_TEST
294 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
296 Support for the BCM2835 auxiliar mini UART.
298 Features and limitations of the UART are
299 Registers are similar to 16650 registers,
300 set bits in the control registers that are unsupported
301 are ignored and read back as 0
302 7/8 bit operation with 1 start and 1 stop bit
303 8 symbols deep fifo for rx and tx
304 SW controlled RTS and SW readable CTS
305 Clock rate derived from system clock
306 Uses 8 times oversampling (compared to 16 times for 16650)
307 Missing break detection (but break generation)
308 Missing framing error detection
310 Missing receive time-out interrupt
311 Missing DCD, DSR, DTR and RI signals
315 config SERIAL_8250_FSL
317 depends on SERIAL_8250_CONSOLE
318 default PPC || ARM || ARM64
320 config SERIAL_8250_DW
321 tristate "Support for Synopsys DesignWare 8250 quirks"
322 depends on SERIAL_8250
324 Selecting this option will enable handling of the extra features
325 present in the Synopsys DesignWare APB UART.
327 config SERIAL_8250_EM
328 tristate "Support for Emma Mobile integrated serial port"
329 depends on SERIAL_8250 && ARM && HAVE_CLK
331 Selecting this option will add support for the integrated serial
332 port hardware found on the Emma Mobile line of processors.
335 config SERIAL_8250_RT288X
336 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
337 depends on SERIAL_8250
338 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
340 Selecting this option will add support for the alternate register
341 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
344 config SERIAL_8250_OMAP
345 tristate "Support for OMAP internal UART (8250 based driver)"
346 depends on SERIAL_8250 && ARCH_OMAP2PLUS
348 If you have a machine based on an Texas Instruments OMAP CPU you
349 can enable its onboard serial ports by enabling this option.
351 This driver uses ttyS instead of ttyO.
353 config SERIAL_8250_OMAP_TTYO_FIXUP
354 bool "Replace ttyO with ttyS"
355 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
358 This option replaces the "console=ttyO" argument with the matching
359 ttyS argument if the user did not specified it on the command line.
360 This ensures that the user can see the kernel output during boot
361 which he wouldn't see otherwise. The getty has still to be configured
362 for ttyS instead of ttyO regardless of this option.
363 This option is intended for people who "automatically" enable this
364 driver without knowing that this driver requires a different console=
365 argument. If you read this, please keep this option disabled and
366 instead update your kernel command line. If you prepare a kernel for a
367 distribution or other kind of larger user base then you probably want
368 to keep this option enabled. Otherwise people might complain about a
369 not booting kernel because the serial console remains silent in case
370 they forgot to update the command line.
372 config SERIAL_8250_LPC18XX
373 tristate "NXP LPC18xx/43xx serial port support"
374 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
377 If you have a LPC18xx/43xx based board and want to use the
378 serial port, say Y to this option. If unsure, say Y.
380 config SERIAL_8250_MT6577
381 tristate "Mediatek serial port support"
382 depends on SERIAL_8250 && ARCH_MEDIATEK
384 If you have a Mediatek based board and want to use the
385 serial port, say Y to this option. If unsure, say N.
387 config SERIAL_8250_UNIPHIER
388 tristate "Support for UniPhier on-chip UART"
389 depends on SERIAL_8250
390 depends on ARCH_UNIPHIER || COMPILE_TEST
392 If you have a UniPhier based board and want to use the on-chip
393 serial ports, say Y to this option. If unsure, say N.
395 config SERIAL_8250_INGENIC
396 tristate "Support for Ingenic SoC serial ports"
397 depends on SERIAL_8250
398 depends on OF_FLATTREE
399 depends on MIPS || COMPILE_TEST
401 If you have a system using an Ingenic SoC and wish to make use of
402 its UARTs, say Y to this option. If unsure, say N.
404 config SERIAL_8250_LPSS
405 tristate "Support for serial ports on Intel LPSS platforms" if EXPERT
407 depends on SERIAL_8250 && PCI
408 depends on X86 || COMPILE_TEST
409 select DW_DMAC_CORE if SERIAL_8250_DMA
410 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
413 Selecting this option will enable handling of the extra features
414 present on the UART found on various Intel platforms such as:
417 - Intel Quark X1000 SoC
419 config SERIAL_8250_MID
420 tristate "Support for serial ports on Intel MID platforms" if EXPERT
422 depends on SERIAL_8250 && PCI
423 depends on X86 || COMPILE_TEST
424 select HSU_DMA if SERIAL_8250_DMA
425 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
428 Selecting this option will enable handling of the extra features
429 present on the UART found on Intel Medfield SOC and various other
432 config SERIAL_8250_MOXA
433 tristate "MOXA SmartIO MUE support"
434 depends on SERIAL_8250 && PCI
436 Say Y here if you have a Moxa SmartIO MUE multiport serial card.
439 This driver can also be built as a module. The module will be called
440 8250_moxa. If you want to do that, say M here.
442 config SERIAL_8250_PXA
443 tristate "PXA serial port support"
444 depends on SERIAL_8250
445 depends on ARCH_PXA || ARCH_MMP
447 If you have a machine based on an Intel XScale PXA2xx CPU you can
448 enable its onboard serial ports by enabling this option. The option is
449 applicable to both devicetree and legacy boards, and early console is
452 config SERIAL_OF_PLATFORM
453 tristate "Devicetree based probing for 8250 ports"
454 depends on SERIAL_8250 && OF
456 This option is used for all 8250 compatible serial ports that
457 are probed through devicetree, including Open Firmware based
458 PowerPC systems and embedded systems on architectures using the
459 flattened device tree format.