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_CONSOLE
61 bool "Console on 8250/16550 and compatible serial port"
62 depends on SERIAL_8250=y
63 select SERIAL_CORE_CONSOLE
64 select SERIAL_EARLYCON
66 If you say Y here, it will be possible to use a serial port as the
67 system console (the system console is the device which receives all
68 kernel messages and warnings and which allows logins in single user
69 mode). This could be useful if some terminal or printer is connected
72 Even if you say Y here, the currently visible virtual console
73 (/dev/tty0) will still be used as the system console by default, but
74 you can alter that using a kernel command line option such as
75 "console=ttyS1". (Try "man bootparam" or see the documentation of
76 your boot loader (grub or lilo or loadlin) about how to pass options
77 to the kernel at boot time.)
79 If you don't have a VGA card installed and you say Y here, the
80 kernel will automatically use the first serial line, /dev/ttyS0, as
83 You can set that using a kernel command line option such as
84 "console=uart8250,io,0x3f8,9600n8"
85 "console=uart8250,mmio,0xff5e0000,115200n8".
86 and it will switch to normal serial console when the corresponding
88 "earlycon=uart8250,io,0x3f8,9600n8"
89 "earlycon=uart8250,mmio,0xff5e0000,115200n8".
90 it will not only setup early console.
94 config SERIAL_8250_GSC
96 depends on SERIAL_8250 && GSC
99 config SERIAL_8250_DMA
100 bool "DMA support for 16550 compatible UART controllers" if EXPERT
101 depends on SERIAL_8250 && DMADEVICES=y
104 This builds DMA support that can be used with 8250/16650
105 compatible UART controllers that support DMA signaling.
107 config SERIAL_8250_PCI
108 tristate "8250/16550 PCI device support" if EXPERT
109 depends on SERIAL_8250 && PCI
113 This builds standard PCI serial support. You may be able to
114 disable this feature if you only need legacy serial support.
116 Note that serial ports on NetMos 9835 Multi-I/O cards are handled
117 by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL.
119 config SERIAL_8250_HP300
121 depends on SERIAL_8250 && HP300
124 config SERIAL_8250_CS
125 tristate "8250/16550 PCMCIA device support"
126 depends on PCMCIA && SERIAL_8250
128 Say Y here to enable support for 16-bit PCMCIA serial devices,
129 including serial port cards, modems, and the modem functions of
130 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
131 credit-card size devices often used with laptops.)
133 To compile this driver as a module, choose M here: the
134 module will be called serial_cs.
138 config SERIAL_8250_NR_UARTS
139 int "Maximum number of 8250/16550 serial ports"
140 depends on SERIAL_8250
143 Set this to the number of serial ports you want the driver
144 to support. This includes any ports discovered via ACPI or
145 PCI enumeration and any ports that may be added at run-time
146 via hot-plug, or any ISA multi-port serial cards.
148 config SERIAL_8250_RUNTIME_UARTS
149 int "Number of 8250/16550 serial ports to register at runtime"
150 depends on SERIAL_8250
151 range 0 SERIAL_8250_NR_UARTS
154 Set this to the maximum number of serial ports you want
155 the kernel to register at boot time. This can be overridden
156 with the module parameter "nr_uarts", or boot-time parameter
159 config SERIAL_8250_EXTENDED
160 bool "Extended 8250/16550 serial driver options"
161 depends on SERIAL_8250
163 If you wish to use any non-standard features of the standard "dumb"
164 driver, say Y here. This includes HUB6 support, shared serial
165 interrupts, special multiport support, support for more than the
166 four COM 1/2/3/4 boards, etc.
168 Note that the answer to this question won't directly affect the
169 kernel: saying N will just cause the configurator to skip all
170 the questions about serial driver options. If unsure, say N.
172 config SERIAL_8250_MANY_PORTS
173 bool "Support more than 4 legacy serial ports"
174 depends on SERIAL_8250_EXTENDED && !IA64
176 Say Y here if you have dumb serial boards other than the four
177 standard COM 1/2/3/4 ports. This may happen if you have an AST
178 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
179 from <http://www.tldp.org/docs.html#howto>), or other custom
180 serial port hardware which acts similar to standard serial port
181 hardware. If you only use the standard COM 1/2/3/4 ports, you can
182 say N here to save some memory. You can also say Y if you have an
183 "intelligent" multiport card such as Cyclades, Digiboards, etc.
186 # Multi-port serial cards
189 config SERIAL_8250_FOURPORT
190 tristate "Support Fourport cards"
191 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
193 Say Y here if you have an AST FourPort serial board.
195 To compile this driver as a module, choose M here: the module
196 will be called 8250_fourport.
198 config SERIAL_8250_ACCENT
199 tristate "Support Accent cards"
200 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
202 Say Y here if you have an Accent Async serial board.
204 To compile this driver as a module, choose M here: the module
205 will be called 8250_accent.
207 config SERIAL_8250_BOCA
208 tristate "Support Boca cards"
209 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
211 Say Y here if you have a Boca serial board. Please read the Boca
212 mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
214 To compile this driver as a module, choose M here: the module
215 will be called 8250_boca.
217 config SERIAL_8250_EXAR_ST16C554
218 tristate "Support Exar ST16C554/554D Quad UART"
219 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
221 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are
222 tinkering with your Envoy TU301, or have a machine with this UART,
225 To compile this driver as a module, choose M here: the module
226 will be called 8250_exar_st16c554.
228 config SERIAL_8250_HUB6
229 tristate "Support Hub6 cards"
230 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
232 Say Y here if you have a HUB6 serial board.
234 To compile this driver as a module, choose M here: the module
235 will be called 8250_hub6.
238 # Misc. options/drivers.
241 config SERIAL_8250_SHARE_IRQ
242 bool "Support for sharing serial interrupts"
243 depends on SERIAL_8250_EXTENDED
245 Some serial boards have hardware support which allows multiple dumb
246 serial ports on the same board to share a single IRQ. To enable
247 support for this in the serial driver, say Y here.
249 config SERIAL_8250_DETECT_IRQ
250 bool "Autodetect IRQ on standard ports (unsafe)"
251 depends on SERIAL_8250_EXTENDED
253 Say Y here if you want the kernel to try to guess which IRQ
254 to use for your serial port.
256 This is considered unsafe; it is far better to configure the IRQ in
257 a boot script using the setserial command.
261 config SERIAL_8250_RSA
262 bool "Support RSA serial ports"
263 depends on SERIAL_8250_EXTENDED
265 ::: To be written :::
267 config SERIAL_8250_ACORN
268 tristate "Acorn expansion card serial port support"
269 depends on ARCH_ACORN && SERIAL_8250
271 If you have an Atomwide Serial card or Serial Port card for an Acorn
272 system, say Y to this option. The driver can handle 1, 2, or 3 port
273 cards. If unsure, say N.
275 config SERIAL_8250_BCM2835AUX
276 tristate "BCM2835 auxiliar mini UART support"
277 depends on ARCH_BCM2835 || COMPILE_TEST
278 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
280 Support for the BCM2835 auxiliar mini UART.
282 Features and limitations of the UART are
283 Registers are similar to 16650 registers,
284 set bits in the control registers that are unsupported
285 are ignored and read back as 0
286 7/8 bit operation with 1 start and 1 stop bit
287 8 symbols deep fifo for rx and tx
288 SW controlled RTS and SW readable CTS
289 Clock rate derived from system clock
290 Uses 8 times oversampling (compared to 16 times for 16650)
291 Missing break detection (but break generation)
292 Missing framing error detection
294 Missing receive time-out interrupt
295 Missing DCD, DSR, DTR and RI signals
299 config SERIAL_8250_FSL
301 depends on SERIAL_8250_CONSOLE
302 default PPC || ARM || ARM64
304 config SERIAL_8250_DW
305 tristate "Support for Synopsys DesignWare 8250 quirks"
306 depends on SERIAL_8250
308 Selecting this option will enable handling of the extra features
309 present in the Synopsys DesignWare APB UART.
311 config SERIAL_8250_EM
312 tristate "Support for Emma Mobile integrated serial port"
313 depends on SERIAL_8250 && ARM && HAVE_CLK
315 Selecting this option will add support for the integrated serial
316 port hardware found on the Emma Mobile line of processors.
319 config SERIAL_8250_RT288X
320 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
321 depends on SERIAL_8250
322 depends on MIPS || COMPILE_TEST
323 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
325 Selecting this option will add support for the alternate register
326 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
329 config SERIAL_8250_OMAP
330 tristate "Support for OMAP internal UART (8250 based driver)"
331 depends on SERIAL_8250 && ARCH_OMAP2PLUS
333 If you have a machine based on an Texas Instruments OMAP CPU you
334 can enable its onboard serial ports by enabling this option.
336 This driver uses ttyS instead of ttyO.
338 config SERIAL_8250_OMAP_TTYO_FIXUP
339 bool "Replace ttyO with ttyS"
340 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
343 This option replaces the "console=ttyO" argument with the matching
344 ttyS argument if the user did not specified it on the command line.
345 This ensures that the user can see the kernel output during boot
346 which he wouldn't see otherwise. The getty has still to be configured
347 for ttyS instead of ttyO regardless of this option.
348 This option is intended for people who "automatically" enable this
349 driver without knowing that this driver requires a different console=
350 argument. If you read this, please keep this option disabled and
351 instead update your kernel command line. If you prepare a kernel for a
352 distribution or other kind of larger user base then you probably want
353 to keep this option enabled. Otherwise people might complain about a
354 not booting kernel because the serial console remains silent in case
355 they forgot to update the command line.
357 config SERIAL_8250_FINTEK
358 tristate "Support for Fintek F81216A LPC to 4 UART"
359 depends on SERIAL_8250 && PNP
361 Selecting this option will add support for the Fintek F81216A
362 LPC to 4 UART. This device has some RS485 functionality not available
363 through the PNP driver. If unsure, say N.
365 config SERIAL_8250_LPC18XX
366 tristate "NXP LPC18xx/43xx serial port support"
367 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
370 If you have a LPC18xx/43xx based board and want to use the
371 serial port, say Y to this option. If unsure, say Y.
373 config SERIAL_8250_MT6577
374 tristate "Mediatek serial port support"
375 depends on SERIAL_8250 && ARCH_MEDIATEK
377 If you have a Mediatek based board and want to use the
378 serial port, say Y to this option. If unsure, say N.
380 config SERIAL_8250_UNIPHIER
381 tristate "Support for UniPhier on-chip UART"
382 depends on SERIAL_8250 && ARCH_UNIPHIER
384 If you have a UniPhier based board and want to use the on-chip
385 serial ports, say Y to this option. If unsure, say N.
387 config SERIAL_8250_INGENIC
388 tristate "Support for Ingenic SoC serial ports"
389 depends on SERIAL_8250
390 depends on (OF_FLATTREE && SERIAL_8250_CONSOLE) || !SERIAL_EARLYCON
391 depends on MIPS || COMPILE_TEST
393 If you have a system using an Ingenic SoC and wish to make use of
394 its UARTs, say Y to this option. If unsure, say N.
396 config SERIAL_8250_MID
397 tristate "Support for serial ports on Intel MID platforms"
398 depends on SERIAL_8250 && PCI
399 select HSU_DMA if SERIAL_8250_DMA
400 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
403 Selecting this option will enable handling of the extra features
404 present on the UART found on Intel Medfield SOC and various other
407 config SERIAL_8250_MOXA
408 tristate "MOXA SmartIO MUE support"
409 depends on SERIAL_8250 && PCI
411 Say Y here if you have a Moxa SmartIO MUE multiport serial card.
414 This driver can also be built as a module. The module will be called
415 8250_moxa. If you want to do that, say M here.
417 config SERIAL_OF_PLATFORM
418 tristate "Devicetree based probing for 8250 ports"
419 depends on SERIAL_8250 && OF
421 This option is used for all 8250 compatible serial ports that
422 are probed through devicetree, including Open Firmware based
423 PowerPC systems and embedded systems on architectures using the
424 flattened device tree format.