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 depends on SERIAL_8250 && PCI 120 121config SERIAL_8250_PCI 122 tristate "8250/16550 PCI device support" 123 depends on SERIAL_8250 && PCI 124 select SERIAL_8250_PCILIB 125 default SERIAL_8250 126 help 127 This builds standard PCI serial support. You may be able to 128 disable this feature if you only need legacy serial support. 129 Saves about 9K. 130 Note that serial ports on NetMos 9835 Multi-I/O cards are handled 131 by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL. 132 133config SERIAL_8250_EXAR 134 tristate "8250/16550 Exar/Commtech PCI/PCIe device support" 135 depends on SERIAL_8250 && PCI 136 select SERIAL_8250_PCILIB 137 select EEPROM_93CX6 138 default SERIAL_8250 139 help 140 This builds support for XR17C1xx, XR17V3xx and some Commtech 141 422x PCIe serial cards that are not covered by the more generic 142 SERIAL_8250_PCI option. 143 144config SERIAL_8250_MOXA_PCIE 145 tristate "8250/16550 Moxa PCIe device support" 146 depends on SERIAL_8250 && PCI 147 default SERIAL_8250 148 help 149 Say Y here if you have a Moxa PCIe serial card. 150 151 To compile this driver as a module, choose M here: the 152 module will be called 8250_mxpcie. 153 154config SERIAL_8250_HP300 155 tristate 156 depends on SERIAL_8250 && HP300 157 default SERIAL_8250 158 159config SERIAL_8250_CS 160 tristate "8250/16550 PCMCIA device support" 161 depends on PCMCIA && SERIAL_8250 && HAS_IOPORT 162 help 163 Say Y here to enable support for 16-bit PCMCIA serial devices, 164 including serial port cards, modems, and the modem functions of 165 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are 166 credit-card size devices often used with laptops.) 167 168 To compile this driver as a module, choose M here: the 169 module will be called serial_cs. 170 171 If unsure, say N. 172 173config SERIAL_8250_MEN_MCB 174 tristate "MEN MCB UART device support" 175 depends on MCB && SERIAL_8250 176 help 177 This enables support for FPGA based UARTs found on many MEN 178 boards. This driver enables support for the 16z025, 16z057 179 and 16z125 UARTs. 180 181 To compile this driver as a module, chose M here: the 182 module will be called 8250_men_mcb. 183 184 185config SERIAL_8250_NR_UARTS 186 int "Maximum number of 8250/16550 serial ports" 187 depends on SERIAL_8250 188 default "4" 189 help 190 Set this to the number of serial ports you want the driver 191 to support. This includes any ports discovered via ACPI or 192 PCI enumeration and any ports that may be added at run-time 193 via hot-plug, or any ISA multi-port serial cards. 194 195config SERIAL_8250_RUNTIME_UARTS 196 int "Number of 8250/16550 serial ports to register at runtime" 197 depends on SERIAL_8250 198 range 0 SERIAL_8250_NR_UARTS 199 default "4" 200 help 201 Set this to the maximum number of serial ports you want 202 the kernel to register at boot time. This can be overridden 203 with the module parameter "nr_uarts", or boot-time parameter 204 8250.nr_uarts 205 206config SERIAL_8250_EXTENDED 207 bool "Extended 8250/16550 serial driver options" 208 depends on SERIAL_8250 209 help 210 If you wish to use any non-standard features of the standard "dumb" 211 driver, say Y here. This includes HUB6 support, shared serial 212 interrupts, special multiport support, support for more than the 213 four COM 1/2/3/4 boards, etc. 214 215 Note that the answer to this question won't directly affect the 216 kernel: saying N will just cause the configurator to skip all 217 the questions about serial driver options. If unsure, say N. 218 219config SERIAL_8250_SHARE_IRQ 220 bool "Support for sharing serial interrupts" 221 depends on SERIAL_8250_EXTENDED 222 help 223 Some serial boards have hardware support which allows multiple dumb 224 serial ports on the same board to share a single IRQ. To enable 225 support for this in the serial driver, say Y here. 226 227config SERIAL_8250_DETECT_IRQ 228 bool "Autodetect IRQ on standard ports (unsafe)" 229 depends on SERIAL_8250_EXTENDED 230 help 231 Say Y here if you want the kernel to try to guess which IRQ 232 to use for your serial port. 233 234 This is considered unsafe; it is far better to configure the IRQ in 235 a boot script using the setserial command. 236 237 If unsure, say N. 238 239config SERIAL_8250_RSA 240 bool "Support RSA serial ports" 241 depends on SERIAL_8250_EXTENDED 242 help 243 Say Y here if you have a IODATA RSA-DV II/S ISA card and 244 would like to use its >115kbps speeds. 245 You will need to provide module parameter "probe_rsa", or boot-time 246 parameter 8250.probe_rsa with I/O addresses of this card then. 247 248 If you don't have such card, or if unsure, say N. 249 250config SERIAL_8250_MANY_PORTS 251 bool "Support more than 4 legacy serial ports" 252 depends on SERIAL_8250_EXTENDED 253 help 254 Say Y here if you have dumb serial boards other than the four 255 standard COM 1/2/3/4 ports. This may happen if you have an AST 256 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available 257 from <https://www.tldp.org/docs.html#howto>), or other custom 258 serial port hardware which acts similar to standard serial port 259 hardware. If you only use the standard COM 1/2/3/4 ports, you can 260 say N here to save some memory. You can also say Y if you have an 261 "intelligent" multiport card such as Digiboards, etc. 262 263# 264# Multi-port serial cards 265# 266 267config SERIAL_8250_FOURPORT 268 tristate "Support Fourport cards" 269 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 270 help 271 Say Y here if you have an AST FourPort serial board. 272 273 To compile this driver as a module, choose M here: the module 274 will be called 8250_fourport. 275 276config SERIAL_8250_ACCENT 277 tristate "Support Accent cards" 278 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 279 help 280 Say Y here if you have an Accent Async serial board. 281 282 To compile this driver as a module, choose M here: the module 283 will be called 8250_accent. 284 285config SERIAL_8250_BOCA 286 tristate "Support Boca cards" 287 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 288 help 289 Say Y here if you have a Boca serial board. Please read the Boca 290 mini-HOWTO, available from <https://www.tldp.org/docs.html#howto> 291 292 To compile this driver as a module, choose M here: the module 293 will be called 8250_boca. 294 295config SERIAL_8250_EXAR_ST16C554 296 tristate "Support Exar ST16C554/554D Quad UART" 297 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 298 help 299 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are 300 tinkering with your Envoy TU301, or have a machine with this UART, 301 say Y here. 302 303 To compile this driver as a module, choose M here: the module 304 will be called 8250_exar_st16c554. 305 306config SERIAL_8250_HUB6 307 tristate "Support Hub6 cards" 308 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 309 help 310 Say Y here if you have a HUB6 serial board. 311 312 To compile this driver as a module, choose M here: the module 313 will be called 8250_hub6. 314 315config SERIAL_8250_PCI1XXXX 316 tristate "Microchip 8250 based serial port" 317 depends on SERIAL_8250 && PCI 318 select SERIAL_8250_PCILIB 319 help 320 Select this option if you have a setup with Microchip PCIe 321 Switch with serial port enabled and wish to enable 8250 322 serial driver for the serial interface. This driver support 323 will ensure to support baud rates upto 1.5Mpbs. 324 325config SERIAL_8250_ASPEED_VUART 326 tristate "Aspeed Virtual UART" 327 depends on SERIAL_8250 328 depends on OF 329 depends on MFD_SYSCON 330 depends on ARCH_ASPEED || COMPILE_TEST 331 select REGMAP 332 help 333 If you want to use the virtual UART (VUART) device on Aspeed 334 BMC platforms, enable this option. This enables the 16550A- 335 compatible device on the local LPC bus, giving a UART device 336 with no physical RS232 connections. 337 338# 339# Misc. options/drivers. 340# 341 342config SERIAL_8250_ACORN 343 tristate "Acorn expansion card serial port support" 344 depends on ARCH_ACORN && SERIAL_8250 345 help 346 If you have an Atomwide Serial card or Serial Port card for an Acorn 347 system, say Y to this option. The driver can handle 1, 2, or 3 port 348 cards. If unsure, say N. 349 350config SERIAL_8250_BCM2835AUX 351 tristate "BCM2835 auxiliar mini UART support" 352 depends on ARCH_BCM2835 || COMPILE_TEST 353 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ 354 help 355 Support for the BCM2835 auxiliar mini UART. 356 357 Features and limitations of the UART are 358 Registers are similar to 16650 registers, 359 set bits in the control registers that are unsupported 360 are ignored and read back as 0 361 7/8 bit operation with 1 start and 1 stop bit 362 8 symbols deep fifo for rx and tx 363 SW controlled RTS and SW readable CTS 364 Clock rate derived from system clock 365 Uses 8 times oversampling (compared to 16 times for 16650) 366 Missing break detection (but break generation) 367 Missing framing error detection 368 Missing parity bit 369 Missing receive time-out interrupt 370 Missing DCD, DSR, DTR and RI signals 371 372 If unsure, say N. 373 374config SERIAL_8250_FSL 375 tristate "Freescale 16550 UART support" if COMPILE_TEST && !(PPC || ARM || ARM64) 376 depends on SERIAL_8250 377 default SERIAL_8250 if PPC || ARM || ARM64 378 help 379 Selecting this option enables a workaround for a break-detection 380 erratum for Freescale 16550 UARTs in the 8250 driver. It also 381 enables support for ACPI enumeration. 382 383config SERIAL_8250_DFL 384 tristate "DFL bus driver for Altera 16550 UART" 385 depends on SERIAL_8250 && FPGA_DFL 386 help 387 This option enables support for a Device Feature List (DFL) bus 388 driver for the Altera 16550 UART. One or more Altera 16550 UARTs 389 can be instantiated in a FPGA and then be discovered during 390 enumeration of the DFL bus. 391 392 To compile this driver as a module, chose M here: the 393 module will be called 8250_dfl. 394 395config SERIAL_8250_DW 396 tristate "Support for Synopsys DesignWare 8250 quirks" 397 depends on SERIAL_8250 398 select SERIAL_8250_DWLIB 399 help 400 Selecting this option will enable handling of the extra features 401 present in the Synopsys DesignWare APB UART. 402 403config SERIAL_8250_EM 404 tristate "Support for Emma Mobile integrated serial port" 405 depends on SERIAL_8250 && HAVE_CLK 406 depends on ARCH_RENESAS || COMPILE_TEST 407 help 408 Selecting this option will add support for the integrated serial 409 port hardware found on the Emma Mobile line of processors. 410 If unsure, say N. 411 412config SERIAL_8250_IOC3 413 tristate "SGI IOC3 8250 UART support" 414 depends on SERIAL_8250 415 depends on SGI_MFD_IOC3 || COMPILE_TEST 416 select SERIAL_8250_EXTENDED 417 select SERIAL_8250_SHARE_IRQ 418 help 419 Enable this if you have a SGI Origin or Octane machine. This module 420 provides basic serial support by directly driving the UART chip 421 behind the IOC3 device on those systems. Maximum baud speed is 422 38400bps using this driver. 423 424config SERIAL_8250_KEBA 425 tristate "Support for KEBA 8250 UART" 426 depends on SERIAL_8250 427 depends on KEBA_CP500 428 help 429 Selecting this option will add support for KEBA UARTs. These UARTs 430 are used for the serial interfaces of KEBA PLCs. 431 432 This driver can also be built as a module. If so, the module will 433 be called 8250_keba. 434 435 If unsure, say N. 436 437config SERIAL_8250_RT288X 438 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support" 439 depends on SERIAL_8250 440 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620 441 help 442 Selecting this option will add support for the alternate register 443 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others. 444 If unsure, say N. 445 446config SERIAL_8250_OMAP 447 tristate "Support for OMAP internal UART (8250 based driver)" 448 depends on SERIAL_8250 449 depends on ARCH_OMAP2PLUS || ARCH_K3 || COMPILE_TEST 450 help 451 If you have a machine based on an Texas Instruments OMAP CPU you 452 can enable its onboard serial ports by enabling this option. 453 454 This driver uses ttyS instead of ttyO. 455 456config SERIAL_8250_OMAP_TTYO_FIXUP 457 bool "Replace ttyO with ttyS" 458 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE 459 default y 460 help 461 This option replaces the "console=ttyO" argument with the matching 462 ttyS argument if the user did not specified it on the command line. 463 This ensures that the user can see the kernel output during boot 464 which he wouldn't see otherwise. The getty has still to be configured 465 for ttyS instead of ttyO regardless of this option. 466 This option is intended for people who "automatically" enable this 467 driver without knowing that this driver requires a different console= 468 argument. If you read this, please keep this option disabled and 469 instead update your kernel command line. If you prepare a kernel for a 470 distribution or other kind of larger user base then you probably want 471 to keep this option enabled. Otherwise people might complain about a 472 not booting kernel because the serial console remains silent in case 473 they forgot to update the command line. 474 475config SERIAL_8250_LOONGSON 476 tristate "Loongson 8250 based serial port" 477 depends on SERIAL_8250 478 depends on LOONGARCH || MACH_LOONGSON64 || COMPILE_TEST 479 help 480 If you have a machine based on LoongArch CPU or MIPS-based Loongson 481 3A4000 CPU you can enable its onboard serial ports by enabling this 482 option. The option is applicable to both devicetree and ACPI, say Y 483 to enable this option. 484 If unsure, say N. 485 486config SERIAL_8250_LPC18XX 487 tristate "NXP LPC18xx/43xx serial port support" 488 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST) 489 default ARCH_LPC18XX 490 help 491 If you have a LPC18xx/43xx based board and want to use the 492 serial port, say Y to this option. If unsure, say Y. 493 494config SERIAL_8250_MT6577 495 tristate "Mediatek serial port support" 496 depends on SERIAL_8250 497 depends on ARCH_MEDIATEK || COMPILE_TEST 498 help 499 If you have a Mediatek based board and want to use the 500 serial port, say Y to this option. If unsure, say N. 501 502config SERIAL_8250_UNIPHIER 503 tristate "Support for UniPhier on-chip UART" 504 depends on SERIAL_8250 505 depends on ARCH_UNIPHIER || COMPILE_TEST 506 help 507 If you have a UniPhier based board and want to use the on-chip 508 serial ports, say Y to this option. If unsure, say N. 509 510config SERIAL_8250_INGENIC 511 tristate "Support for Ingenic SoC serial ports" 512 depends on SERIAL_8250 513 depends on OF_FLATTREE 514 depends on MIPS || COMPILE_TEST 515 help 516 If you have a system using an Ingenic SoC and wish to make use of 517 its UARTs, say Y to this option. If unsure, say N. 518 519config SERIAL_8250_LPSS 520 tristate "Support for serial ports on Intel LPSS platforms" 521 default SERIAL_8250 522 depends on SERIAL_8250 && PCI 523 depends on X86 || COMPILE_TEST 524 select SERIAL_8250_DWLIB 525 select DW_DMAC_CORE if SERIAL_8250_DMA 526 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS) 527 select RATIONAL 528 help 529 Selecting this option will enable handling of the UART found on 530 various Intel platforms such as: 531 - Intel Baytrail SoC 532 - Intel Braswell SoC 533 - Intel Quark X1000 SoC 534 that are not covered by the more generic SERIAL_8250_PCI option. 535 536config SERIAL_8250_MID 537 tristate "Support for serial ports on Intel MID platforms" 538 default SERIAL_8250 539 depends on SERIAL_8250 && PCI 540 depends on X86 || COMPILE_TEST 541 select HSU_DMA if SERIAL_8250_DMA 542 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID) 543 select RATIONAL 544 help 545 Selecting this option will enable handling of the UART found on 546 Intel Medfield SOC and various other Intel platforms that is not 547 covered by the more generic SERIAL_8250_PCI option. 548 549config SERIAL_8250_PERICOM 550 tristate "Support for Pericom and Acces I/O serial ports" 551 default SERIAL_8250 552 depends on SERIAL_8250 && PCI 553 help 554 Selecting this option will enable handling of the Pericom and Acces 555 I/O UARTs that are not covered by the more generic SERIAL_8250_PCI 556 option. 557 558config SERIAL_8250_PXA 559 tristate "PXA serial port support" 560 depends on SERIAL_8250 561 depends on ARCH_PXA || ARCH_MMP || COMPILE_TEST 562 help 563 If you have a machine based on an Intel XScale PXA2xx CPU you can 564 enable its onboard serial ports by enabling this option. The option is 565 applicable to both devicetree and legacy boards, and early console is 566 part of its support. 567 568config SERIAL_8250_TEGRA 569 tristate "8250 support for Tegra serial ports" 570 default SERIAL_8250 571 depends on SERIAL_8250 572 depends on ARCH_TEGRA || COMPILE_TEST 573 help 574 Select this option if you have machine with an NVIDIA Tegra SoC and 575 wish to enable 8250 serial driver for the Tegra serial interfaces. 576 577config SERIAL_8250_BCM7271 578 tristate "Broadcom 8250 based serial port" 579 depends on SERIAL_8250 && (ARCH_BRCMSTB || COMPILE_TEST) 580 default ARCH_BRCMSTB 581 help 582 If you have a Broadcom STB based board and want to use the 583 enhanced features of the Broadcom 8250 based serial port, 584 including DMA support and high accuracy BAUD rates, say 585 Y to this option. If unsure, say N. 586 587config SERIAL_8250_NI 588 tristate "NI 16550 based serial port" 589 depends on SERIAL_8250 590 depends on X86 || COMPILE_TEST 591 help 592 This driver supports the integrated serial ports on National 593 Instruments (NI) controller hardware. This is required for all NI 594 controller models with onboard RS-485 or dual-mode RS-485/RS-232 595 ports. 596 597 To compile this driver as a module, choose M here: the module 598 will be called 8250_ni. 599 600config SERIAL_OF_PLATFORM 601 tristate "Devicetree based probing for 8250 ports" 602 depends on SERIAL_8250 && OF 603 help 604 This option is used for all 8250 compatible serial ports that 605 are probed through devicetree, including Open Firmware based 606 PowerPC systems and embedded systems on architectures using the 607 flattened device tree format. 608 609config SERIAL_8250_DWLIB 610 bool 611