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
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_HP300
133 depends on SERIAL_8250 && HP300
136 config SERIAL_8250_CS
137 tristate "8250/16550 PCMCIA device support"
138 depends on PCMCIA && SERIAL_8250
140 Say Y here to enable support for 16-bit PCMCIA serial devices,
141 including serial port cards, modems, and the modem functions of
142 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
143 credit-card size devices often used with laptops.)
145 To compile this driver as a module, choose M here: the
146 module will be called serial_cs.
150 config SERIAL_8250_NR_UARTS
151 int "Maximum number of 8250/16550 serial ports"
152 depends on SERIAL_8250
155 Set this to the number of serial ports you want the driver
156 to support. This includes any ports discovered via ACPI or
157 PCI enumeration and any ports that may be added at run-time
158 via hot-plug, or any ISA multi-port serial cards.
160 config SERIAL_8250_RUNTIME_UARTS
161 int "Number of 8250/16550 serial ports to register at runtime"
162 depends on SERIAL_8250
163 range 0 SERIAL_8250_NR_UARTS
166 Set this to the maximum number of serial ports you want
167 the kernel to register at boot time. This can be overridden
168 with the module parameter "nr_uarts", or boot-time parameter
171 config SERIAL_8250_EXTENDED
172 bool "Extended 8250/16550 serial driver options"
173 depends on SERIAL_8250
175 If you wish to use any non-standard features of the standard "dumb"
176 driver, say Y here. This includes HUB6 support, shared serial
177 interrupts, special multiport support, support for more than the
178 four COM 1/2/3/4 boards, etc.
180 Note that the answer to this question won't directly affect the
181 kernel: saying N will just cause the configurator to skip all
182 the questions about serial driver options. If unsure, say N.
184 config SERIAL_8250_MANY_PORTS
185 bool "Support more than 4 legacy serial ports"
186 depends on SERIAL_8250_EXTENDED && !IA64
188 Say Y here if you have dumb serial boards other than the four
189 standard COM 1/2/3/4 ports. This may happen if you have an AST
190 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
191 from <http://www.tldp.org/docs.html#howto>), or other custom
192 serial port hardware which acts similar to standard serial port
193 hardware. If you only use the standard COM 1/2/3/4 ports, you can
194 say N here to save some memory. You can also say Y if you have an
195 "intelligent" multiport card such as Cyclades, Digiboards, etc.
198 # Multi-port serial cards
201 config SERIAL_8250_FOURPORT
202 tristate "Support Fourport cards"
203 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
205 Say Y here if you have an AST FourPort serial board.
207 To compile this driver as a module, choose M here: the module
208 will be called 8250_fourport.
210 config SERIAL_8250_ACCENT
211 tristate "Support Accent cards"
212 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
214 Say Y here if you have an Accent Async serial board.
216 To compile this driver as a module, choose M here: the module
217 will be called 8250_accent.
219 config SERIAL_8250_BOCA
220 tristate "Support Boca cards"
221 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
223 Say Y here if you have a Boca serial board. Please read the Boca
224 mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
226 To compile this driver as a module, choose M here: the module
227 will be called 8250_boca.
229 config SERIAL_8250_EXAR_ST16C554
230 tristate "Support Exar ST16C554/554D Quad UART"
231 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
233 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are
234 tinkering with your Envoy TU301, or have a machine with this UART,
237 To compile this driver as a module, choose M here: the module
238 will be called 8250_exar_st16c554.
240 config SERIAL_8250_HUB6
241 tristate "Support Hub6 cards"
242 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
244 Say Y here if you have a HUB6 serial board.
246 To compile this driver as a module, choose M here: the module
247 will be called 8250_hub6.
250 # Misc. options/drivers.
253 config SERIAL_8250_SHARE_IRQ
254 bool "Support for sharing serial interrupts"
255 depends on SERIAL_8250_EXTENDED
257 Some serial boards have hardware support which allows multiple dumb
258 serial ports on the same board to share a single IRQ. To enable
259 support for this in the serial driver, say Y here.
261 config SERIAL_8250_DETECT_IRQ
262 bool "Autodetect IRQ on standard ports (unsafe)"
263 depends on SERIAL_8250_EXTENDED
265 Say Y here if you want the kernel to try to guess which IRQ
266 to use for your serial port.
268 This is considered unsafe; it is far better to configure the IRQ in
269 a boot script using the setserial command.
273 config SERIAL_8250_RSA
274 bool "Support RSA serial ports"
275 depends on SERIAL_8250_EXTENDED
277 Say Y here if you have a IODATA RSA-DV II/S ISA card and
278 would like to use its >115kbps speeds.
279 You will need to provide module parameter "probe_rsa", or boot-time
280 parameter 8250.probe_rsa with I/O addresses of this card then.
282 If you don't have such card, or if unsure, say N.
284 config SERIAL_8250_ACORN
285 tristate "Acorn expansion card serial port support"
286 depends on ARCH_ACORN && SERIAL_8250
288 If you have an Atomwide Serial card or Serial Port card for an Acorn
289 system, say Y to this option. The driver can handle 1, 2, or 3 port
290 cards. If unsure, say N.
292 config SERIAL_8250_BCM2835AUX
293 tristate "BCM2835 auxiliar mini UART support"
294 depends on ARCH_BCM2835 || COMPILE_TEST
295 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
297 Support for the BCM2835 auxiliar mini UART.
299 Features and limitations of the UART are
300 Registers are similar to 16650 registers,
301 set bits in the control registers that are unsupported
302 are ignored and read back as 0
303 7/8 bit operation with 1 start and 1 stop bit
304 8 symbols deep fifo for rx and tx
305 SW controlled RTS and SW readable CTS
306 Clock rate derived from system clock
307 Uses 8 times oversampling (compared to 16 times for 16650)
308 Missing break detection (but break generation)
309 Missing framing error detection
311 Missing receive time-out interrupt
312 Missing DCD, DSR, DTR and RI signals
316 config SERIAL_8250_FSL
318 depends on SERIAL_8250_CONSOLE
319 default PPC || ARM || ARM64
321 config SERIAL_8250_DW
322 tristate "Support for Synopsys DesignWare 8250 quirks"
323 depends on SERIAL_8250
325 Selecting this option will enable handling of the extra features
326 present in the Synopsys DesignWare APB UART.
328 config SERIAL_8250_EM
329 tristate "Support for Emma Mobile integrated serial port"
330 depends on SERIAL_8250 && ARM && HAVE_CLK
332 Selecting this option will add support for the integrated serial
333 port hardware found on the Emma Mobile line of processors.
336 config SERIAL_8250_RT288X
337 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
338 depends on SERIAL_8250
339 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
341 Selecting this option will add support for the alternate register
342 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
345 config SERIAL_8250_OMAP
346 tristate "Support for OMAP internal UART (8250 based driver)"
347 depends on SERIAL_8250 && ARCH_OMAP2PLUS
349 If you have a machine based on an Texas Instruments OMAP CPU you
350 can enable its onboard serial ports by enabling this option.
352 This driver uses ttyS instead of ttyO.
354 config SERIAL_8250_OMAP_TTYO_FIXUP
355 bool "Replace ttyO with ttyS"
356 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
359 This option replaces the "console=ttyO" argument with the matching
360 ttyS argument if the user did not specified it on the command line.
361 This ensures that the user can see the kernel output during boot
362 which he wouldn't see otherwise. The getty has still to be configured
363 for ttyS instead of ttyO regardless of this option.
364 This option is intended for people who "automatically" enable this
365 driver without knowing that this driver requires a different console=
366 argument. If you read this, please keep this option disabled and
367 instead update your kernel command line. If you prepare a kernel for a
368 distribution or other kind of larger user base then you probably want
369 to keep this option enabled. Otherwise people might complain about a
370 not booting kernel because the serial console remains silent in case
371 they forgot to update the command line.
373 config SERIAL_8250_LPC18XX
374 tristate "NXP LPC18xx/43xx serial port support"
375 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
378 If you have a LPC18xx/43xx based board and want to use the
379 serial port, say Y to this option. If unsure, say Y.
381 config SERIAL_8250_MT6577
382 tristate "Mediatek serial port support"
383 depends on SERIAL_8250 && ARCH_MEDIATEK
385 If you have a Mediatek based board and want to use the
386 serial port, say Y to this option. If unsure, say N.
388 config SERIAL_8250_UNIPHIER
389 tristate "Support for UniPhier on-chip UART"
390 depends on SERIAL_8250
391 depends on ARCH_UNIPHIER || COMPILE_TEST
393 If you have a UniPhier based board and want to use the on-chip
394 serial ports, say Y to this option. If unsure, say N.
396 config SERIAL_8250_INGENIC
397 tristate "Support for Ingenic SoC serial ports"
398 depends on SERIAL_8250
399 depends on OF_FLATTREE
400 depends on MIPS || COMPILE_TEST
402 If you have a system using an Ingenic SoC and wish to make use of
403 its UARTs, say Y to this option. If unsure, say N.
405 config SERIAL_8250_MID
406 tristate "Support for serial ports on Intel MID platforms" if EXPERT
408 depends on SERIAL_8250 && PCI
409 depends on X86 || COMPILE_TEST
410 select HSU_DMA if SERIAL_8250_DMA
411 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
414 Selecting this option will enable handling of the extra features
415 present on the UART found on Intel Medfield SOC and various other
418 config SERIAL_8250_MOXA
419 tristate "MOXA SmartIO MUE support"
420 depends on SERIAL_8250 && PCI
422 Say Y here if you have a Moxa SmartIO MUE multiport serial card.
425 This driver can also be built as a module. The module will be called
426 8250_moxa. If you want to do that, say M here.
428 config SERIAL_OF_PLATFORM
429 tristate "Devicetree based probing for 8250 ports"
430 depends on SERIAL_8250 && OF
432 This option is used for all 8250 compatible serial ports that
433 are probed through devicetree, including Open Firmware based
434 PowerPC systems and embedded systems on architectures using the
435 flattened device tree format.