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 select SERIAL_MCTRL_GPIO if GPIOLIB 12 help 13 This selects whether you want to include the driver for the standard 14 serial ports. The standard answer is Y. People who might say N 15 here are those that are setting up dedicated Ethernet WWW/FTP 16 servers, or users that have one of the various bus mice instead of a 17 serial mouse and don't intend to use their machine's standard serial 18 port for anything. 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_PNP 38 bool "8250/16550 PNP device support" if EXPERT 39 depends on SERIAL_8250 && PNP 40 default y 41 help 42 This builds standard PNP serial support. You may be able to 43 disable this feature if you only need legacy serial support. 44 45config SERIAL_8250_16550A_VARIANTS 46 bool "Support for variants of the 16550A serial port" 47 depends on SERIAL_8250 48 default !X86 49 help 50 The 8250 driver can probe for many variants of the venerable 16550A 51 serial port. Doing so takes additional time at boot. 52 53 On modern systems, especially those using serial only for a simple 54 console, you can say N here. 55 56config SERIAL_8250_FINTEK 57 bool "Support for Fintek variants" 58 depends on SERIAL_8250 && HAS_IOPORT 59 help 60 Selecting this option will add support for the RS232 and RS485 61 capabilities of the Fintek F81216A LPC to 4 UART as well similar 62 variants. 63 64 If this option is not selected the device will be configured as a 65 standard 16550A serial port, however the device may not function 66 correctly without this option enabled. 67 68 If unsure, say N. 69 70config SERIAL_8250_CONSOLE 71 bool "Console on 8250/16550 and compatible serial port" 72 depends on SERIAL_8250=y 73 select SERIAL_CORE_CONSOLE 74 select SERIAL_EARLYCON 75 help 76 If you say Y here, it will be possible to use a serial port as the 77 system console (the system console is the device which receives all 78 kernel messages and warnings and which allows logins in single user 79 mode). This could be useful if some terminal or printer is connected 80 to that serial port. 81 82 Even if you say Y here, the currently visible virtual console 83 (/dev/tty0) will still be used as the system console by default, but 84 you can alter that using a kernel command line option such as 85 "console=ttyS1". (Try "man bootparam" or see the documentation of 86 your boot loader (grub or lilo or loadlin) about how to pass options 87 to the kernel at boot time.) 88 89 If you don't have a VGA card installed and you say Y here, the 90 kernel will automatically use the first serial line, /dev/ttyS0, as 91 system console. 92 93 You can set that using a kernel command line option such as 94 "console=uart8250,io,0x3f8,9600n8" 95 "console=uart8250,mmio,0xff5e0000,115200n8". 96 and it will switch to normal serial console when the corresponding 97 port is ready. 98 "earlycon=uart8250,io,0x3f8,9600n8" 99 "earlycon=uart8250,mmio,0xff5e0000,115200n8". 100 it will not only setup early console. 101 102 If unsure, say N. 103 104config SERIAL_8250_PARISC 105 tristate 106 depends on SERIAL_8250 && PARISC 107 default SERIAL_8250 108 109config SERIAL_8250_DMA 110 bool "DMA support for 16550 compatible UART controllers" if EXPERT 111 depends on SERIAL_8250 && DMADEVICES=y 112 default SERIAL_8250 113 help 114 This builds DMA support that can be used with 8250/16650 115 compatible UART controllers that support DMA signaling. 116 117config SERIAL_8250_PCILIB 118 bool 119 120config SERIAL_8250_PCI 121 tristate "8250/16550 PCI device support" 122 depends on SERIAL_8250 && PCI 123 select SERIAL_8250_PCILIB 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 select SERIAL_8250_PCILIB 136 select EEPROM_93CX6 137 default SERIAL_8250 138 help 139 This builds support for XR17C1xx, XR17V3xx and some Commtech 140 422x PCIe serial cards that are not covered by the more generic 141 SERIAL_8250_PCI option. 142 143config SERIAL_8250_HP300 144 tristate 145 depends on SERIAL_8250 && HP300 146 default SERIAL_8250 147 148config SERIAL_8250_CS 149 tristate "8250/16550 PCMCIA device support" 150 depends on PCMCIA && SERIAL_8250 && HAS_IOPORT 151 help 152 Say Y here to enable support for 16-bit PCMCIA serial devices, 153 including serial port cards, modems, and the modem functions of 154 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are 155 credit-card size devices often used with laptops.) 156 157 To compile this driver as a module, choose M here: the 158 module will be called serial_cs. 159 160 If unsure, say N. 161 162config SERIAL_8250_MEN_MCB 163 tristate "MEN MCB UART device support" 164 depends on MCB && SERIAL_8250 165 help 166 This enables support for FPGA based UARTs found on many MEN 167 boards. This driver enables support for the 16z025, 16z057 168 and 16z125 UARTs. 169 170 To compile this driver as a module, chose M here: the 171 module will be called 8250_men_mcb. 172 173 174config SERIAL_8250_NR_UARTS 175 int "Maximum number of 8250/16550 serial ports" 176 depends on SERIAL_8250 177 default "4" 178 help 179 Set this to the number of serial ports you want the driver 180 to support. This includes any ports discovered via ACPI or 181 PCI enumeration and any ports that may be added at run-time 182 via hot-plug, or any ISA multi-port serial cards. 183 184config SERIAL_8250_RUNTIME_UARTS 185 int "Number of 8250/16550 serial ports to register at runtime" 186 depends on SERIAL_8250 187 range 0 SERIAL_8250_NR_UARTS 188 default "4" 189 help 190 Set this to the maximum number of serial ports you want 191 the kernel to register at boot time. This can be overridden 192 with the module parameter "nr_uarts", or boot-time parameter 193 8250.nr_uarts 194 195config SERIAL_8250_EXTENDED 196 bool "Extended 8250/16550 serial driver options" 197 depends on SERIAL_8250 198 help 199 If you wish to use any non-standard features of the standard "dumb" 200 driver, say Y here. This includes HUB6 support, shared serial 201 interrupts, special multiport support, support for more than the 202 four COM 1/2/3/4 boards, etc. 203 204 Note that the answer to this question won't directly affect the 205 kernel: saying N will just cause the configurator to skip all 206 the questions about serial driver options. If unsure, say N. 207 208config SERIAL_8250_MANY_PORTS 209 bool "Support more than 4 legacy serial ports" 210 depends on SERIAL_8250_EXTENDED 211 help 212 Say Y here if you have dumb serial boards other than the four 213 standard COM 1/2/3/4 ports. This may happen if you have an AST 214 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available 215 from <https://www.tldp.org/docs.html#howto>), or other custom 216 serial port hardware which acts similar to standard serial port 217 hardware. If you only use the standard COM 1/2/3/4 ports, you can 218 say N here to save some memory. You can also say Y if you have an 219 "intelligent" multiport card such as Digiboards, etc. 220 221# 222# Multi-port serial cards 223# 224 225config SERIAL_8250_FOURPORT 226 tristate "Support Fourport cards" 227 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 228 help 229 Say Y here if you have an AST FourPort serial board. 230 231 To compile this driver as a module, choose M here: the module 232 will be called 8250_fourport. 233 234config SERIAL_8250_ACCENT 235 tristate "Support Accent cards" 236 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 237 help 238 Say Y here if you have an Accent Async serial board. 239 240 To compile this driver as a module, choose M here: the module 241 will be called 8250_accent. 242 243config SERIAL_8250_ASPEED_VUART 244 tristate "Aspeed Virtual UART" 245 depends on SERIAL_8250 246 depends on OF 247 depends on MFD_SYSCON 248 depends on ARCH_ASPEED || COMPILE_TEST 249 select REGMAP 250 help 251 If you want to use the virtual UART (VUART) device on Aspeed 252 BMC platforms, enable this option. This enables the 16550A- 253 compatible device on the local LPC bus, giving a UART device 254 with no physical RS232 connections. 255 256config SERIAL_8250_BOCA 257 tristate "Support Boca cards" 258 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 259 help 260 Say Y here if you have a Boca serial board. Please read the Boca 261 mini-HOWTO, available from <https://www.tldp.org/docs.html#howto> 262 263 To compile this driver as a module, choose M here: the module 264 will be called 8250_boca. 265 266config SERIAL_8250_EXAR_ST16C554 267 tristate "Support Exar ST16C554/554D Quad UART" 268 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 269 help 270 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are 271 tinkering with your Envoy TU301, or have a machine with this UART, 272 say Y here. 273 274 To compile this driver as a module, choose M here: the module 275 will be called 8250_exar_st16c554. 276 277config SERIAL_8250_HUB6 278 tristate "Support Hub6 cards" 279 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 280 help 281 Say Y here if you have a HUB6 serial board. 282 283 To compile this driver as a module, choose M here: the module 284 will be called 8250_hub6. 285 286config SERIAL_8250_PCI1XXXX 287 tristate "Microchip 8250 based serial port" 288 depends on SERIAL_8250 && PCI 289 select SERIAL_8250_PCILIB 290 help 291 Select this option if you have a setup with Microchip PCIe 292 Switch with serial port enabled and wish to enable 8250 293 serial driver for the serial interface. This driver support 294 will ensure to support baud rates upto 1.5Mpbs. 295 296# 297# Misc. options/drivers. 298# 299 300config SERIAL_8250_SHARE_IRQ 301 bool "Support for sharing serial interrupts" 302 depends on SERIAL_8250_EXTENDED 303 help 304 Some serial boards have hardware support which allows multiple dumb 305 serial ports on the same board to share a single IRQ. To enable 306 support for this in the serial driver, say Y here. 307 308config SERIAL_8250_DETECT_IRQ 309 bool "Autodetect IRQ on standard ports (unsafe)" 310 depends on SERIAL_8250_EXTENDED 311 help 312 Say Y here if you want the kernel to try to guess which IRQ 313 to use for your serial port. 314 315 This is considered unsafe; it is far better to configure the IRQ in 316 a boot script using the setserial command. 317 318 If unsure, say N. 319 320config SERIAL_8250_RSA 321 bool "Support RSA serial ports" 322 depends on SERIAL_8250_EXTENDED 323 help 324 Say Y here if you have a IODATA RSA-DV II/S ISA card and 325 would like to use its >115kbps speeds. 326 You will need to provide module parameter "probe_rsa", or boot-time 327 parameter 8250.probe_rsa with I/O addresses of this card then. 328 329 If you don't have such card, or if unsure, say N. 330 331config SERIAL_8250_DWLIB 332 bool 333 334config SERIAL_8250_ACORN 335 tristate "Acorn expansion card serial port support" 336 depends on ARCH_ACORN && SERIAL_8250 337 help 338 If you have an Atomwide Serial card or Serial Port card for an Acorn 339 system, say Y to this option. The driver can handle 1, 2, or 3 port 340 cards. If unsure, say N. 341 342config SERIAL_8250_BCM2835AUX 343 tristate "BCM2835 auxiliar mini UART support" 344 depends on ARCH_BCM2835 || COMPILE_TEST 345 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ 346 help 347 Support for the BCM2835 auxiliar mini UART. 348 349 Features and limitations of the UART are 350 Registers are similar to 16650 registers, 351 set bits in the control registers that are unsupported 352 are ignored and read back as 0 353 7/8 bit operation with 1 start and 1 stop bit 354 8 symbols deep fifo for rx and tx 355 SW controlled RTS and SW readable CTS 356 Clock rate derived from system clock 357 Uses 8 times oversampling (compared to 16 times for 16650) 358 Missing break detection (but break generation) 359 Missing framing error detection 360 Missing parity bit 361 Missing receive time-out interrupt 362 Missing DCD, DSR, DTR and RI signals 363 364 If unsure, say N. 365 366config SERIAL_8250_FSL 367 tristate "Freescale 16550 UART support" if COMPILE_TEST && !(PPC || ARM || ARM64) 368 depends on SERIAL_8250 369 default SERIAL_8250 if PPC || ARM || ARM64 370 help 371 Selecting this option enables a workaround for a break-detection 372 erratum for Freescale 16550 UARTs in the 8250 driver. It also 373 enables support for ACPI enumeration. 374 375config SERIAL_8250_DFL 376 tristate "DFL bus driver for Altera 16550 UART" 377 depends on SERIAL_8250 && FPGA_DFL 378 help 379 This option enables support for a Device Feature List (DFL) bus 380 driver for the Altera 16550 UART. One or more Altera 16550 UARTs 381 can be instantiated in a FPGA and then be discovered during 382 enumeration of the DFL bus. 383 384 To compile this driver as a module, chose M here: the 385 module will be called 8250_dfl. 386 387config SERIAL_8250_DW 388 tristate "Support for Synopsys DesignWare 8250 quirks" 389 depends on SERIAL_8250 390 select SERIAL_8250_DWLIB 391 help 392 Selecting this option will enable handling of the extra features 393 present in the Synopsys DesignWare APB UART. 394 395config SERIAL_8250_EM 396 tristate "Support for Emma Mobile integrated serial port" 397 depends on SERIAL_8250 && HAVE_CLK 398 depends on ARCH_RENESAS || COMPILE_TEST 399 help 400 Selecting this option will add support for the integrated serial 401 port hardware found on the Emma Mobile line of processors. 402 If unsure, say N. 403 404config SERIAL_8250_IOC3 405 tristate "SGI IOC3 8250 UART support" 406 depends on SERIAL_8250 407 depends on SGI_MFD_IOC3 || COMPILE_TEST 408 select SERIAL_8250_EXTENDED 409 select SERIAL_8250_SHARE_IRQ 410 help 411 Enable this if you have a SGI Origin or Octane machine. This module 412 provides basic serial support by directly driving the UART chip 413 behind the IOC3 device on those systems. Maximum baud speed is 414 38400bps using this driver. 415 416config SERIAL_8250_KEBA 417 tristate "Support for KEBA 8250 UART" 418 depends on SERIAL_8250 419 depends on KEBA_CP500 420 help 421 Selecting this option will add support for KEBA UARTs. These UARTs 422 are used for the serial interfaces of KEBA PLCs. 423 424 This driver can also be built as a module. If so, the module will 425 be called 8250_keba. 426 427 If unsure, say N. 428 429config SERIAL_8250_RT288X 430 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support" 431 depends on SERIAL_8250 432 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620 433 help 434 Selecting this option will add support for the alternate register 435 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others. 436 If unsure, say N. 437 438config SERIAL_8250_OMAP 439 tristate "Support for OMAP internal UART (8250 based driver)" 440 depends on SERIAL_8250 441 depends on ARCH_OMAP2PLUS || ARCH_K3 || COMPILE_TEST 442 help 443 If you have a machine based on an Texas Instruments OMAP CPU you 444 can enable its onboard serial ports by enabling this option. 445 446 This driver uses ttyS instead of ttyO. 447 448config SERIAL_8250_OMAP_TTYO_FIXUP 449 bool "Replace ttyO with ttyS" 450 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE 451 default y 452 help 453 This option replaces the "console=ttyO" argument with the matching 454 ttyS argument if the user did not specified it on the command line. 455 This ensures that the user can see the kernel output during boot 456 which he wouldn't see otherwise. The getty has still to be configured 457 for ttyS instead of ttyO regardless of this option. 458 This option is intended for people who "automatically" enable this 459 driver without knowing that this driver requires a different console= 460 argument. If you read this, please keep this option disabled and 461 instead update your kernel command line. If you prepare a kernel for a 462 distribution or other kind of larger user base then you probably want 463 to keep this option enabled. Otherwise people might complain about a 464 not booting kernel because the serial console remains silent in case 465 they forgot to update the command line. 466 467config SERIAL_8250_LOONGSON 468 tristate "Loongson 8250 based serial port" 469 depends on SERIAL_8250 470 depends on LOONGARCH || COMPILE_TEST 471 help 472 If you have a machine based on LoongArch CPU you can enable 473 its onboard serial ports by enabling this option. The option 474 is applicable to both devicetree and ACPI, say Y to this option. 475 If unsure, say N. 476 477config SERIAL_8250_LPC18XX 478 tristate "NXP LPC18xx/43xx serial port support" 479 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST) 480 default ARCH_LPC18XX 481 help 482 If you have a LPC18xx/43xx based board and want to use the 483 serial port, say Y to this option. If unsure, say Y. 484 485config SERIAL_8250_MT6577 486 tristate "Mediatek serial port support" 487 depends on SERIAL_8250 488 depends on ARCH_MEDIATEK || COMPILE_TEST 489 help 490 If you have a Mediatek based board and want to use the 491 serial port, say Y to this option. If unsure, say N. 492 493config SERIAL_8250_UNIPHIER 494 tristate "Support for UniPhier on-chip UART" 495 depends on SERIAL_8250 496 depends on ARCH_UNIPHIER || COMPILE_TEST 497 help 498 If you have a UniPhier based board and want to use the on-chip 499 serial ports, say Y to this option. If unsure, say N. 500 501config SERIAL_8250_INGENIC 502 tristate "Support for Ingenic SoC serial ports" 503 depends on SERIAL_8250 504 depends on OF_FLATTREE 505 depends on MIPS || COMPILE_TEST 506 help 507 If you have a system using an Ingenic SoC and wish to make use of 508 its UARTs, say Y to this option. If unsure, say N. 509 510config SERIAL_8250_LPSS 511 tristate "Support for serial ports on Intel LPSS platforms" 512 default SERIAL_8250 513 depends on SERIAL_8250 && PCI 514 depends on X86 || COMPILE_TEST 515 select SERIAL_8250_DWLIB 516 select DW_DMAC_CORE if SERIAL_8250_DMA 517 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS) 518 select RATIONAL 519 help 520 Selecting this option will enable handling of the UART found on 521 various Intel platforms such as: 522 - Intel Baytrail SoC 523 - Intel Braswell SoC 524 - Intel Quark X1000 SoC 525 that are not covered by the more generic SERIAL_8250_PCI option. 526 527config SERIAL_8250_MID 528 tristate "Support for serial ports on Intel MID platforms" 529 default SERIAL_8250 530 depends on SERIAL_8250 && PCI 531 depends on X86 || COMPILE_TEST 532 select HSU_DMA if SERIAL_8250_DMA 533 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID) 534 select RATIONAL 535 help 536 Selecting this option will enable handling of the UART found on 537 Intel Medfield SOC and various other Intel platforms that is not 538 covered by the more generic SERIAL_8250_PCI option. 539 540config SERIAL_8250_PERICOM 541 tristate "Support for Pericom and Acces I/O serial ports" 542 default SERIAL_8250 543 depends on SERIAL_8250 && PCI 544 help 545 Selecting this option will enable handling of the Pericom and Acces 546 I/O UARTs that are not covered by the more generic SERIAL_8250_PCI 547 option. 548 549config SERIAL_8250_PXA 550 tristate "PXA serial port support" 551 depends on SERIAL_8250 552 depends on ARCH_PXA || ARCH_MMP || COMPILE_TEST 553 help 554 If you have a machine based on an Intel XScale PXA2xx CPU you can 555 enable its onboard serial ports by enabling this option. The option is 556 applicable to both devicetree and legacy boards, and early console is 557 part of its support. 558 559config SERIAL_8250_TEGRA 560 tristate "8250 support for Tegra serial ports" 561 default SERIAL_8250 562 depends on SERIAL_8250 563 depends on ARCH_TEGRA || COMPILE_TEST 564 help 565 Select this option if you have machine with an NVIDIA Tegra SoC and 566 wish to enable 8250 serial driver for the Tegra serial interfaces. 567 568config SERIAL_8250_BCM7271 569 tristate "Broadcom 8250 based serial port" 570 depends on SERIAL_8250 && (ARCH_BRCMSTB || COMPILE_TEST) 571 default ARCH_BRCMSTB 572 help 573 If you have a Broadcom STB based board and want to use the 574 enhanced features of the Broadcom 8250 based serial port, 575 including DMA support and high accuracy BAUD rates, say 576 Y to this option. If unsure, say N. 577 578config SERIAL_8250_NI 579 tristate "NI 16550 based serial port" 580 depends on SERIAL_8250 581 depends on X86 || COMPILE_TEST 582 help 583 This driver supports the integrated serial ports on National 584 Instruments (NI) controller hardware. This is required for all NI 585 controller models with onboard RS-485 or dual-mode RS-485/RS-232 586 ports. 587 588 To compile this driver as a module, choose M here: the module 589 will be called 8250_ni. 590 591config SERIAL_OF_PLATFORM 592 tristate "Devicetree based probing for 8250 ports" 593 depends on SERIAL_8250 && OF 594 help 595 This option is used for all 8250 compatible serial ports that 596 are probed through devicetree, including Open Firmware based 597 PowerPC systems and embedded systems on architectures using the 598 flattened device tree format. 599