1# SPDX-License-Identifier: GPL-2.0 2# 3# The 8250/16550 serial drivers. You shouldn't be in this list unless 4# you somehow have an implicit or explicit dependency on SERIAL_8250. 5# 6 7config SERIAL_8250 8 tristate "8250/16550 and compatible serial support" 9 depends on !S390 10 select SERIAL_CORE 11 ---help--- 12 This selects whether you want to include the driver for the standard 13 serial ports. The standard answer is Y. People who might say N 14 here are those that are setting up dedicated Ethernet WWW/FTP 15 servers, or users that have one of the various bus mice instead of a 16 serial mouse and don't intend to use their machine's standard serial 17 port for anything. (Note that the Cyclades multi serial port driver 18 does not need this driver built in for it to work.) 19 20 To compile this driver as a module, choose M here: the 21 module will be called 8250. 22 [WARNING: Do not compile this driver as a module if you are using 23 non-standard serial ports, since the configuration information will 24 be lost when the driver is unloaded. This limitation may be lifted 25 in the future.] 26 27 BTW1: If you have a mouseman serial mouse which is not recognized by 28 the X window system, try running gpm first. 29 30 BTW2: If you intend to use a software modem (also called Winmodem) 31 under Linux, forget it. These modems are crippled and require 32 proprietary drivers which are only available under Windows. 33 34 Most people will say Y or M here, so that they can use serial mice, 35 modems and similar devices connecting to the standard serial ports. 36 37config SERIAL_8250_DEPRECATED_OPTIONS 38 bool "Support 8250_core.* kernel options (DEPRECATED)" 39 depends on SERIAL_8250 40 default y 41 ---help--- 42 In 3.7 we renamed 8250 to 8250_core by mistake, so now we have to 43 accept kernel parameters in both forms like 8250_core.nr_uarts=4 and 44 8250.nr_uarts=4. We now renamed the module back to 8250, but if 45 anybody noticed in 3.7 and changed their userspace we still have to 46 keep the 8250_core.* options around until they revert the changes 47 they already did. 48 49 If 8250 is built as a module, this adds 8250_core alias instead. 50 51 If you did not notice yet and/or you have userspace from pre-3.7, it 52 is safe (and recommended) to say N here. 53 54config SERIAL_8250_PNP 55 bool "8250/16550 PNP device support" if EXPERT 56 depends on SERIAL_8250 && PNP 57 default y 58 ---help--- 59 This builds standard PNP serial support. You may be able to 60 disable this feature if you only need legacy serial support. 61 62config SERIAL_8250_FINTEK 63 bool "Support for Fintek F81216A LPC to 4 UART RS485 API" 64 depends on SERIAL_8250 65 ---help--- 66 Selecting this option will add support for the RS485 capabilities 67 of the Fintek F81216A LPC to 4 UART. 68 69 If this option is not selected the device will be configured as a 70 standard 16550A serial port. 71 72 If unsure, say N. 73 74config SERIAL_8250_CONSOLE 75 bool "Console on 8250/16550 and compatible serial port" 76 depends on SERIAL_8250=y 77 select SERIAL_CORE_CONSOLE 78 select SERIAL_EARLYCON 79 ---help--- 80 If you say Y here, it will be possible to use a serial port as the 81 system console (the system console is the device which receives all 82 kernel messages and warnings and which allows logins in single user 83 mode). This could be useful if some terminal or printer is connected 84 to that serial port. 85 86 Even if you say Y here, the currently visible virtual console 87 (/dev/tty0) will still be used as the system console by default, but 88 you can alter that using a kernel command line option such as 89 "console=ttyS1". (Try "man bootparam" or see the documentation of 90 your boot loader (grub or lilo or loadlin) about how to pass options 91 to the kernel at boot time.) 92 93 If you don't have a VGA card installed and you say Y here, the 94 kernel will automatically use the first serial line, /dev/ttyS0, as 95 system console. 96 97 You can set that using a kernel command line option such as 98 "console=uart8250,io,0x3f8,9600n8" 99 "console=uart8250,mmio,0xff5e0000,115200n8". 100 and it will switch to normal serial console when the corresponding 101 port is ready. 102 "earlycon=uart8250,io,0x3f8,9600n8" 103 "earlycon=uart8250,mmio,0xff5e0000,115200n8". 104 it will not only setup early console. 105 106 If unsure, say N. 107 108config SERIAL_8250_GSC 109 tristate 110 depends on SERIAL_8250 && GSC 111 default SERIAL_8250 112 113config SERIAL_8250_DMA 114 bool "DMA support for 16550 compatible UART controllers" if EXPERT 115 depends on SERIAL_8250 && DMADEVICES=y 116 default SERIAL_8250 117 help 118 This builds DMA support that can be used with 8250/16650 119 compatible UART controllers that support DMA signaling. 120 121config SERIAL_8250_PCI 122 tristate "8250/16550 PCI device support" 123 depends on SERIAL_8250 && PCI 124 default SERIAL_8250 125 help 126 This builds standard PCI serial support. You may be able to 127 disable this feature if you only need legacy serial support. 128 Saves about 9K. 129 Note that serial ports on NetMos 9835 Multi-I/O cards are handled 130 by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL. 131 132config SERIAL_8250_EXAR 133 tristate "8250/16550 Exar/Commtech PCI/PCIe device support" 134 depends on SERIAL_8250_PCI 135 default SERIAL_8250 136 help 137 This builds support for XR17C1xx, XR17V3xx and some Commtech 138 422x PCIe serial cards that are not covered by the more generic 139 SERIAL_8250_PCI option. 140 141config SERIAL_8250_HP300 142 tristate 143 depends on SERIAL_8250 && HP300 144 default SERIAL_8250 145 146config SERIAL_8250_CS 147 tristate "8250/16550 PCMCIA device support" 148 depends on PCMCIA && SERIAL_8250 149 ---help--- 150 Say Y here to enable support for 16-bit PCMCIA serial devices, 151 including serial port cards, modems, and the modem functions of 152 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are 153 credit-card size devices often used with laptops.) 154 155 To compile this driver as a module, choose M here: the 156 module will be called serial_cs. 157 158 If unsure, say N. 159 160config SERIAL_8250_MEN_MCB 161 tristate "MEN MCB UART device support" 162 depends on MCB && SERIAL_8250 163 help 164 This enables support for FPGA based UARTs found on many MEN 165 boards. This driver enables support for the 16z025, 16z057 166 and 16z125 UARTs. 167 168 To compile this driver as a module, chose M here: the 169 module will be called 8250_men_mcb. 170 171 172config SERIAL_8250_NR_UARTS 173 int "Maximum number of 8250/16550 serial ports" 174 depends on SERIAL_8250 175 default "4" 176 help 177 Set this to the number of serial ports you want the driver 178 to support. This includes any ports discovered via ACPI or 179 PCI enumeration and any ports that may be added at run-time 180 via hot-plug, or any ISA multi-port serial cards. 181 182config SERIAL_8250_RUNTIME_UARTS 183 int "Number of 8250/16550 serial ports to register at runtime" 184 depends on SERIAL_8250 185 range 0 SERIAL_8250_NR_UARTS 186 default "4" 187 help 188 Set this to the maximum number of serial ports you want 189 the kernel to register at boot time. This can be overridden 190 with the module parameter "nr_uarts", or boot-time parameter 191 8250.nr_uarts 192 193config SERIAL_8250_EXTENDED 194 bool "Extended 8250/16550 serial driver options" 195 depends on SERIAL_8250 196 help 197 If you wish to use any non-standard features of the standard "dumb" 198 driver, say Y here. This includes HUB6 support, shared serial 199 interrupts, special multiport support, support for more than the 200 four COM 1/2/3/4 boards, etc. 201 202 Note that the answer to this question won't directly affect the 203 kernel: saying N will just cause the configurator to skip all 204 the questions about serial driver options. If unsure, say N. 205 206config SERIAL_8250_MANY_PORTS 207 bool "Support more than 4 legacy serial ports" 208 depends on SERIAL_8250_EXTENDED && !IA64 209 help 210 Say Y here if you have dumb serial boards other than the four 211 standard COM 1/2/3/4 ports. This may happen if you have an AST 212 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available 213 from <http://www.tldp.org/docs.html#howto>), or other custom 214 serial port hardware which acts similar to standard serial port 215 hardware. If you only use the standard COM 1/2/3/4 ports, you can 216 say N here to save some memory. You can also say Y if you have an 217 "intelligent" multiport card such as Cyclades, Digiboards, etc. 218 219# 220# Multi-port serial cards 221# 222 223config SERIAL_8250_FOURPORT 224 tristate "Support Fourport cards" 225 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 226 help 227 Say Y here if you have an AST FourPort serial board. 228 229 To compile this driver as a module, choose M here: the module 230 will be called 8250_fourport. 231 232config SERIAL_8250_ACCENT 233 tristate "Support Accent cards" 234 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 235 help 236 Say Y here if you have an Accent Async serial board. 237 238 To compile this driver as a module, choose M here: the module 239 will be called 8250_accent. 240 241config SERIAL_8250_ASPEED_VUART 242 tristate "Aspeed Virtual UART" 243 depends on SERIAL_8250 244 depends on OF 245 help 246 If you want to use the virtual UART (VUART) device on Aspeed 247 BMC platforms, enable this option. This enables the 16550A- 248 compatible device on the local LPC bus, giving a UART device 249 with no physical RS232 connections. 250 251config SERIAL_8250_BOCA 252 tristate "Support Boca cards" 253 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 254 help 255 Say Y here if you have a Boca serial board. Please read the Boca 256 mini-HOWTO, available from <http://www.tldp.org/docs.html#howto> 257 258 To compile this driver as a module, choose M here: the module 259 will be called 8250_boca. 260 261config SERIAL_8250_EXAR_ST16C554 262 tristate "Support Exar ST16C554/554D Quad UART" 263 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 264 help 265 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are 266 tinkering with your Envoy TU301, or have a machine with this UART, 267 say Y here. 268 269 To compile this driver as a module, choose M here: the module 270 will be called 8250_exar_st16c554. 271 272config SERIAL_8250_HUB6 273 tristate "Support Hub6 cards" 274 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 275 help 276 Say Y here if you have a HUB6 serial board. 277 278 To compile this driver as a module, choose M here: the module 279 will be called 8250_hub6. 280 281# 282# Misc. options/drivers. 283# 284 285config SERIAL_8250_SHARE_IRQ 286 bool "Support for sharing serial interrupts" 287 depends on SERIAL_8250_EXTENDED 288 help 289 Some serial boards have hardware support which allows multiple dumb 290 serial ports on the same board to share a single IRQ. To enable 291 support for this in the serial driver, say Y here. 292 293config SERIAL_8250_DETECT_IRQ 294 bool "Autodetect IRQ on standard ports (unsafe)" 295 depends on SERIAL_8250_EXTENDED 296 help 297 Say Y here if you want the kernel to try to guess which IRQ 298 to use for your serial port. 299 300 This is considered unsafe; it is far better to configure the IRQ in 301 a boot script using the setserial command. 302 303 If unsure, say N. 304 305config SERIAL_8250_RSA 306 bool "Support RSA serial ports" 307 depends on SERIAL_8250_EXTENDED 308 help 309 Say Y here if you have a IODATA RSA-DV II/S ISA card and 310 would like to use its >115kbps speeds. 311 You will need to provide module parameter "probe_rsa", or boot-time 312 parameter 8250.probe_rsa with I/O addresses of this card then. 313 314 If you don't have such card, or if unsure, say N. 315 316config SERIAL_8250_ACORN 317 tristate "Acorn expansion card serial port support" 318 depends on ARCH_ACORN && SERIAL_8250 319 help 320 If you have an Atomwide Serial card or Serial Port card for an Acorn 321 system, say Y to this option. The driver can handle 1, 2, or 3 port 322 cards. If unsure, say N. 323 324config SERIAL_8250_BCM2835AUX 325 tristate "BCM2835 auxiliar mini UART support" 326 depends on ARCH_BCM2835 || COMPILE_TEST 327 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ 328 help 329 Support for the BCM2835 auxiliar mini UART. 330 331 Features and limitations of the UART are 332 Registers are similar to 16650 registers, 333 set bits in the control registers that are unsupported 334 are ignored and read back as 0 335 7/8 bit operation with 1 start and 1 stop bit 336 8 symbols deep fifo for rx and tx 337 SW controlled RTS and SW readable CTS 338 Clock rate derived from system clock 339 Uses 8 times oversampling (compared to 16 times for 16650) 340 Missing break detection (but break generation) 341 Missing framing error detection 342 Missing parity bit 343 Missing receive time-out interrupt 344 Missing DCD, DSR, DTR and RI signals 345 346 If unsure, say N. 347 348config SERIAL_8250_FSL 349 bool 350 depends on SERIAL_8250_CONSOLE 351 default PPC || ARM || ARM64 352 353config SERIAL_8250_DW 354 tristate "Support for Synopsys DesignWare 8250 quirks" 355 depends on SERIAL_8250 356 help 357 Selecting this option will enable handling of the extra features 358 present in the Synopsys DesignWare APB UART. 359 360config SERIAL_8250_EM 361 tristate "Support for Emma Mobile integrated serial port" 362 depends on SERIAL_8250 && ARM && HAVE_CLK 363 help 364 Selecting this option will add support for the integrated serial 365 port hardware found on the Emma Mobile line of processors. 366 If unsure, say N. 367 368config SERIAL_8250_RT288X 369 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support" 370 depends on SERIAL_8250 371 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620 372 help 373 Selecting this option will add support for the alternate register 374 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others. 375 If unsure, say N. 376 377config SERIAL_8250_OMAP 378 tristate "Support for OMAP internal UART (8250 based driver)" 379 depends on SERIAL_8250 && (ARCH_OMAP2PLUS || ARCH_K3) 380 help 381 If you have a machine based on an Texas Instruments OMAP CPU you 382 can enable its onboard serial ports by enabling this option. 383 384 This driver uses ttyS instead of ttyO. 385 386config SERIAL_8250_OMAP_TTYO_FIXUP 387 bool "Replace ttyO with ttyS" 388 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE 389 default y 390 help 391 This option replaces the "console=ttyO" argument with the matching 392 ttyS argument if the user did not specified it on the command line. 393 This ensures that the user can see the kernel output during boot 394 which he wouldn't see otherwise. The getty has still to be configured 395 for ttyS instead of ttyO regardless of this option. 396 This option is intended for people who "automatically" enable this 397 driver without knowing that this driver requires a different console= 398 argument. If you read this, please keep this option disabled and 399 instead update your kernel command line. If you prepare a kernel for a 400 distribution or other kind of larger user base then you probably want 401 to keep this option enabled. Otherwise people might complain about a 402 not booting kernel because the serial console remains silent in case 403 they forgot to update the command line. 404 405config SERIAL_8250_LPC18XX 406 tristate "NXP LPC18xx/43xx serial port support" 407 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST) 408 default ARCH_LPC18XX 409 help 410 If you have a LPC18xx/43xx based board and want to use the 411 serial port, say Y to this option. If unsure, say Y. 412 413config SERIAL_8250_MT6577 414 tristate "Mediatek serial port support" 415 depends on SERIAL_8250 && ARCH_MEDIATEK 416 help 417 If you have a Mediatek based board and want to use the 418 serial port, say Y to this option. If unsure, say N. 419 420config SERIAL_8250_UNIPHIER 421 tristate "Support for UniPhier on-chip UART" 422 depends on SERIAL_8250 423 depends on ARCH_UNIPHIER || COMPILE_TEST 424 help 425 If you have a UniPhier based board and want to use the on-chip 426 serial ports, say Y to this option. If unsure, say N. 427 428config SERIAL_8250_INGENIC 429 tristate "Support for Ingenic SoC serial ports" 430 depends on SERIAL_8250 431 depends on OF_FLATTREE 432 depends on MIPS || COMPILE_TEST 433 help 434 If you have a system using an Ingenic SoC and wish to make use of 435 its UARTs, say Y to this option. If unsure, say N. 436 437config SERIAL_8250_LPSS 438 tristate "Support for serial ports on Intel LPSS platforms" 439 default SERIAL_8250 440 depends on SERIAL_8250 && PCI 441 depends on X86 || COMPILE_TEST 442 select DW_DMAC_CORE if SERIAL_8250_DMA 443 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS) 444 select RATIONAL 445 help 446 Selecting this option will enable handling of the extra features 447 present on the UART found on various Intel platforms such as: 448 - Intel Baytrail SoC 449 - Intel Braswell SoC 450 - Intel Quark X1000 SoC 451 452config SERIAL_8250_MID 453 tristate "Support for serial ports on Intel MID platforms" 454 default SERIAL_8250 455 depends on SERIAL_8250 && PCI 456 depends on X86 || COMPILE_TEST 457 select HSU_DMA if SERIAL_8250_DMA 458 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID) 459 select RATIONAL 460 help 461 Selecting this option will enable handling of the extra features 462 present on the UART found on Intel Medfield SOC and various other 463 Intel platforms. 464 465config SERIAL_8250_MOXA 466 tristate "MOXA SmartIO MUE support" 467 depends on SERIAL_8250 && PCI 468 help 469 Say Y here if you have a Moxa SmartIO MUE multiport serial card. 470 If unsure, say N. 471 472 This driver can also be built as a module. The module will be called 473 8250_moxa. If you want to do that, say M here. 474 475config SERIAL_8250_PXA 476 tristate "PXA serial port support" 477 depends on SERIAL_8250 478 depends on ARCH_PXA || ARCH_MMP 479 help 480 If you have a machine based on an Intel XScale PXA2xx CPU you can 481 enable its onboard serial ports by enabling this option. The option is 482 applicable to both devicetree and legacy boards, and early console is 483 part of its support. 484 485config SERIAL_OF_PLATFORM 486 tristate "Devicetree based probing for 8250 ports" 487 depends on SERIAL_8250 && OF 488 help 489 This option is used for all 8250 compatible serial ports that 490 are probed through devicetree, including Open Firmware based 491 PowerPC systems and embedded systems on architectures using the 492 flattened device tree format. 493