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_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_16550A_VARIANTS 63 bool "Support for variants of the 16550A serial port" 64 depends on SERIAL_8250 65 default !X86 66 help 67 The 8250 driver can probe for many variants of the venerable 16550A 68 serial port. Doing so takes additional time at boot. 69 70 On modern systems, especially those using serial only for a simple 71 console, you can say N here. 72 73config SERIAL_8250_FINTEK 74 bool "Support for Fintek variants" 75 depends on SERIAL_8250 76 help 77 Selecting this option will add support for the RS232 and RS485 78 capabilities of the Fintek F81216A LPC to 4 UART as well similar 79 variants. 80 81 If this option is not selected the device will be configured as a 82 standard 16550A serial port, however the device may not function 83 correctly without this option enabled. 84 85 If unsure, say N. 86 87config SERIAL_8250_CONSOLE 88 bool "Console on 8250/16550 and compatible serial port" 89 depends on SERIAL_8250=y 90 select SERIAL_CORE_CONSOLE 91 select SERIAL_EARLYCON 92 help 93 If you say Y here, it will be possible to use a serial port as the 94 system console (the system console is the device which receives all 95 kernel messages and warnings and which allows logins in single user 96 mode). This could be useful if some terminal or printer is connected 97 to that serial port. 98 99 Even if you say Y here, the currently visible virtual console 100 (/dev/tty0) will still be used as the system console by default, but 101 you can alter that using a kernel command line option such as 102 "console=ttyS1". (Try "man bootparam" or see the documentation of 103 your boot loader (grub or lilo or loadlin) about how to pass options 104 to the kernel at boot time.) 105 106 If you don't have a VGA card installed and you say Y here, the 107 kernel will automatically use the first serial line, /dev/ttyS0, as 108 system console. 109 110 You can set that using a kernel command line option such as 111 "console=uart8250,io,0x3f8,9600n8" 112 "console=uart8250,mmio,0xff5e0000,115200n8". 113 and it will switch to normal serial console when the corresponding 114 port is ready. 115 "earlycon=uart8250,io,0x3f8,9600n8" 116 "earlycon=uart8250,mmio,0xff5e0000,115200n8". 117 it will not only setup early console. 118 119 If unsure, say N. 120 121config SERIAL_8250_PARISC 122 tristate 123 depends on SERIAL_8250 && PARISC 124 default SERIAL_8250 125 126config SERIAL_8250_DMA 127 bool "DMA support for 16550 compatible UART controllers" if EXPERT 128 depends on SERIAL_8250 && DMADEVICES=y 129 default SERIAL_8250 130 help 131 This builds DMA support that can be used with 8250/16650 132 compatible UART controllers that support DMA signaling. 133 134config SERIAL_8250_PCILIB 135 bool 136 137config SERIAL_8250_PCI 138 tristate "8250/16550 PCI device support" 139 depends on SERIAL_8250 && PCI 140 select SERIAL_8250_PCILIB 141 default SERIAL_8250 142 help 143 This builds standard PCI serial support. You may be able to 144 disable this feature if you only need legacy serial support. 145 Saves about 9K. 146 Note that serial ports on NetMos 9835 Multi-I/O cards are handled 147 by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL. 148 149config SERIAL_8250_EXAR 150 tristate "8250/16550 Exar/Commtech PCI/PCIe device support" 151 depends on SERIAL_8250 && PCI 152 select SERIAL_8250_PCILIB 153 default SERIAL_8250 154 help 155 This builds support for XR17C1xx, XR17V3xx and some Commtech 156 422x PCIe serial cards that are not covered by the more generic 157 SERIAL_8250_PCI option. 158 159config SERIAL_8250_HP300 160 tristate 161 depends on SERIAL_8250 && HP300 162 default SERIAL_8250 163 164config SERIAL_8250_CS 165 tristate "8250/16550 PCMCIA device support" 166 depends on PCMCIA && SERIAL_8250 167 help 168 Say Y here to enable support for 16-bit PCMCIA serial devices, 169 including serial port cards, modems, and the modem functions of 170 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are 171 credit-card size devices often used with laptops.) 172 173 To compile this driver as a module, choose M here: the 174 module will be called serial_cs. 175 176 If unsure, say N. 177 178config SERIAL_8250_MEN_MCB 179 tristate "MEN MCB UART device support" 180 depends on MCB && SERIAL_8250 181 help 182 This enables support for FPGA based UARTs found on many MEN 183 boards. This driver enables support for the 16z025, 16z057 184 and 16z125 UARTs. 185 186 To compile this driver as a module, chose M here: the 187 module will be called 8250_men_mcb. 188 189 190config SERIAL_8250_NR_UARTS 191 int "Maximum number of 8250/16550 serial ports" 192 depends on SERIAL_8250 193 default "4" 194 help 195 Set this to the number of serial ports you want the driver 196 to support. This includes any ports discovered via ACPI or 197 PCI enumeration and any ports that may be added at run-time 198 via hot-plug, or any ISA multi-port serial cards. 199 200config SERIAL_8250_RUNTIME_UARTS 201 int "Number of 8250/16550 serial ports to register at runtime" 202 depends on SERIAL_8250 203 range 0 SERIAL_8250_NR_UARTS 204 default "4" 205 help 206 Set this to the maximum number of serial ports you want 207 the kernel to register at boot time. This can be overridden 208 with the module parameter "nr_uarts", or boot-time parameter 209 8250.nr_uarts 210 211config SERIAL_8250_EXTENDED 212 bool "Extended 8250/16550 serial driver options" 213 depends on SERIAL_8250 214 help 215 If you wish to use any non-standard features of the standard "dumb" 216 driver, say Y here. This includes HUB6 support, shared serial 217 interrupts, special multiport support, support for more than the 218 four COM 1/2/3/4 boards, etc. 219 220 Note that the answer to this question won't directly affect the 221 kernel: saying N will just cause the configurator to skip all 222 the questions about serial driver options. If unsure, say N. 223 224config SERIAL_8250_MANY_PORTS 225 bool "Support more than 4 legacy serial ports" 226 depends on SERIAL_8250_EXTENDED 227 help 228 Say Y here if you have dumb serial boards other than the four 229 standard COM 1/2/3/4 ports. This may happen if you have an AST 230 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available 231 from <https://www.tldp.org/docs.html#howto>), or other custom 232 serial port hardware which acts similar to standard serial port 233 hardware. If you only use the standard COM 1/2/3/4 ports, you can 234 say N here to save some memory. You can also say Y if you have an 235 "intelligent" multiport card such as Digiboards, etc. 236 237# 238# Multi-port serial cards 239# 240 241config SERIAL_8250_FOURPORT 242 tristate "Support Fourport cards" 243 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 244 help 245 Say Y here if you have an AST FourPort serial board. 246 247 To compile this driver as a module, choose M here: the module 248 will be called 8250_fourport. 249 250config SERIAL_8250_ACCENT 251 tristate "Support Accent cards" 252 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 253 help 254 Say Y here if you have an Accent Async serial board. 255 256 To compile this driver as a module, choose M here: the module 257 will be called 8250_accent. 258 259config SERIAL_8250_ASPEED_VUART 260 tristate "Aspeed Virtual UART" 261 depends on SERIAL_8250 262 depends on OF 263 depends on MFD_SYSCON 264 depends on ARCH_ASPEED || COMPILE_TEST 265 select REGMAP 266 help 267 If you want to use the virtual UART (VUART) device on Aspeed 268 BMC platforms, enable this option. This enables the 16550A- 269 compatible device on the local LPC bus, giving a UART device 270 with no physical RS232 connections. 271 272config SERIAL_8250_BOCA 273 tristate "Support Boca cards" 274 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 275 help 276 Say Y here if you have a Boca serial board. Please read the Boca 277 mini-HOWTO, available from <https://www.tldp.org/docs.html#howto> 278 279 To compile this driver as a module, choose M here: the module 280 will be called 8250_boca. 281 282config SERIAL_8250_EXAR_ST16C554 283 tristate "Support Exar ST16C554/554D Quad UART" 284 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 285 help 286 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are 287 tinkering with your Envoy TU301, or have a machine with this UART, 288 say Y here. 289 290 To compile this driver as a module, choose M here: the module 291 will be called 8250_exar_st16c554. 292 293config SERIAL_8250_HUB6 294 tristate "Support Hub6 cards" 295 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 296 help 297 Say Y here if you have a HUB6 serial board. 298 299 To compile this driver as a module, choose M here: the module 300 will be called 8250_hub6. 301 302config SERIAL_8250_PCI1XXXX 303 tristate "Microchip 8250 based serial port" 304 depends on SERIAL_8250 && PCI 305 select SERIAL_8250_PCILIB 306 help 307 Select this option if you have a setup with Microchip PCIe 308 Switch with serial port enabled and wish to enable 8250 309 serial driver for the serial interface. This driver support 310 will ensure to support baud rates upto 1.5Mpbs. 311 312# 313# Misc. options/drivers. 314# 315 316config SERIAL_8250_SHARE_IRQ 317 bool "Support for sharing serial interrupts" 318 depends on SERIAL_8250_EXTENDED 319 help 320 Some serial boards have hardware support which allows multiple dumb 321 serial ports on the same board to share a single IRQ. To enable 322 support for this in the serial driver, say Y here. 323 324config SERIAL_8250_DETECT_IRQ 325 bool "Autodetect IRQ on standard ports (unsafe)" 326 depends on SERIAL_8250_EXTENDED 327 help 328 Say Y here if you want the kernel to try to guess which IRQ 329 to use for your serial port. 330 331 This is considered unsafe; it is far better to configure the IRQ in 332 a boot script using the setserial command. 333 334 If unsure, say N. 335 336config SERIAL_8250_RSA 337 bool "Support RSA serial ports" 338 depends on SERIAL_8250_EXTENDED 339 help 340 Say Y here if you have a IODATA RSA-DV II/S ISA card and 341 would like to use its >115kbps speeds. 342 You will need to provide module parameter "probe_rsa", or boot-time 343 parameter 8250.probe_rsa with I/O addresses of this card then. 344 345 If you don't have such card, or if unsure, say N. 346 347config SERIAL_8250_DWLIB 348 bool 349 350config SERIAL_8250_ACORN 351 tristate "Acorn expansion card serial port support" 352 depends on ARCH_ACORN && SERIAL_8250 353 help 354 If you have an Atomwide Serial card or Serial Port card for an Acorn 355 system, say Y to this option. The driver can handle 1, 2, or 3 port 356 cards. If unsure, say N. 357 358config SERIAL_8250_BCM2835AUX 359 tristate "BCM2835 auxiliar mini UART support" 360 depends on ARCH_BCM2835 || COMPILE_TEST 361 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ 362 help 363 Support for the BCM2835 auxiliar mini UART. 364 365 Features and limitations of the UART are 366 Registers are similar to 16650 registers, 367 set bits in the control registers that are unsupported 368 are ignored and read back as 0 369 7/8 bit operation with 1 start and 1 stop bit 370 8 symbols deep fifo for rx and tx 371 SW controlled RTS and SW readable CTS 372 Clock rate derived from system clock 373 Uses 8 times oversampling (compared to 16 times for 16650) 374 Missing break detection (but break generation) 375 Missing framing error detection 376 Missing parity bit 377 Missing receive time-out interrupt 378 Missing DCD, DSR, DTR and RI signals 379 380 If unsure, say N. 381 382config SERIAL_8250_FSL 383 tristate "Freescale 16550 UART support" if COMPILE_TEST && !(PPC || ARM || ARM64) 384 depends on SERIAL_8250 385 default SERIAL_8250 if PPC || ARM || ARM64 386 help 387 Selecting this option enables a workaround for a break-detection 388 erratum for Freescale 16550 UARTs in the 8250 driver. It also 389 enables support for ACPI enumeration. 390 391config SERIAL_8250_DFL 392 tristate "DFL bus driver for Altera 16550 UART" 393 depends on SERIAL_8250 && FPGA_DFL 394 help 395 This option enables support for a Device Feature List (DFL) bus 396 driver for the Altera 16550 UART. One or more Altera 16550 UARTs 397 can be instantiated in a FPGA and then be discovered during 398 enumeration of the DFL bus. 399 400 To compile this driver as a module, chose M here: the 401 module will be called 8250_dfl. 402 403config SERIAL_8250_DW 404 tristate "Support for Synopsys DesignWare 8250 quirks" 405 depends on SERIAL_8250 406 select SERIAL_8250_DWLIB 407 help 408 Selecting this option will enable handling of the extra features 409 present in the Synopsys DesignWare APB UART. 410 411config SERIAL_8250_EM 412 tristate "Support for Emma Mobile integrated serial port" 413 depends on SERIAL_8250 && HAVE_CLK 414 depends on ARCH_RENESAS || COMPILE_TEST 415 help 416 Selecting this option will add support for the integrated serial 417 port hardware found on the Emma Mobile line of processors. 418 If unsure, say N. 419 420config SERIAL_8250_IOC3 421 tristate "SGI IOC3 8250 UART support" 422 depends on SERIAL_8250 423 depends on SGI_MFD_IOC3 || COMPILE_TEST 424 select SERIAL_8250_EXTENDED 425 select SERIAL_8250_SHARE_IRQ 426 help 427 Enable this if you have a SGI Origin or Octane machine. This module 428 provides basic serial support by directly driving the UART chip 429 behind the IOC3 device on those systems. Maximum baud speed is 430 38400bps using this driver. 431 432config SERIAL_8250_RT288X 433 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support" 434 depends on SERIAL_8250 435 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620 436 help 437 Selecting this option will add support for the alternate register 438 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others. 439 If unsure, say N. 440 441config SERIAL_8250_OMAP 442 tristate "Support for OMAP internal UART (8250 based driver)" 443 depends on SERIAL_8250 444 depends on ARCH_OMAP2PLUS || ARCH_K3 || COMPILE_TEST 445 help 446 If you have a machine based on an Texas Instruments OMAP CPU you 447 can enable its onboard serial ports by enabling this option. 448 449 This driver uses ttyS instead of ttyO. 450 451config SERIAL_8250_OMAP_TTYO_FIXUP 452 bool "Replace ttyO with ttyS" 453 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE 454 default y 455 help 456 This option replaces the "console=ttyO" argument with the matching 457 ttyS argument if the user did not specified it on the command line. 458 This ensures that the user can see the kernel output during boot 459 which he wouldn't see otherwise. The getty has still to be configured 460 for ttyS instead of ttyO regardless of this option. 461 This option is intended for people who "automatically" enable this 462 driver without knowing that this driver requires a different console= 463 argument. If you read this, please keep this option disabled and 464 instead update your kernel command line. If you prepare a kernel for a 465 distribution or other kind of larger user base then you probably want 466 to keep this option enabled. Otherwise people might complain about a 467 not booting kernel because the serial console remains silent in case 468 they forgot to update the command line. 469 470config SERIAL_8250_LPC18XX 471 tristate "NXP LPC18xx/43xx serial port support" 472 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST) 473 default ARCH_LPC18XX 474 help 475 If you have a LPC18xx/43xx based board and want to use the 476 serial port, say Y to this option. If unsure, say Y. 477 478config SERIAL_8250_MT6577 479 tristate "Mediatek serial port support" 480 depends on SERIAL_8250 481 depends on ARCH_MEDIATEK || COMPILE_TEST 482 help 483 If you have a Mediatek based board and want to use the 484 serial port, say Y to this option. If unsure, say N. 485 486config SERIAL_8250_UNIPHIER 487 tristate "Support for UniPhier on-chip UART" 488 depends on SERIAL_8250 489 depends on ARCH_UNIPHIER || COMPILE_TEST 490 help 491 If you have a UniPhier based board and want to use the on-chip 492 serial ports, say Y to this option. If unsure, say N. 493 494config SERIAL_8250_INGENIC 495 tristate "Support for Ingenic SoC serial ports" 496 depends on SERIAL_8250 497 depends on OF_FLATTREE 498 depends on MIPS || COMPILE_TEST 499 help 500 If you have a system using an Ingenic SoC and wish to make use of 501 its UARTs, say Y to this option. If unsure, say N. 502 503config SERIAL_8250_LPSS 504 tristate "Support for serial ports on Intel LPSS platforms" 505 default SERIAL_8250 506 depends on SERIAL_8250 && PCI 507 depends on X86 || COMPILE_TEST 508 select SERIAL_8250_DWLIB 509 select DW_DMAC_CORE if SERIAL_8250_DMA 510 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS) 511 select RATIONAL 512 help 513 Selecting this option will enable handling of the UART found on 514 various Intel platforms such as: 515 - Intel Baytrail SoC 516 - Intel Braswell SoC 517 - Intel Quark X1000 SoC 518 that are not covered by the more generic SERIAL_8250_PCI option. 519 520config SERIAL_8250_MID 521 tristate "Support for serial ports on Intel MID platforms" 522 default SERIAL_8250 523 depends on SERIAL_8250 && PCI 524 depends on X86 || COMPILE_TEST 525 select HSU_DMA if SERIAL_8250_DMA 526 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID) 527 select RATIONAL 528 help 529 Selecting this option will enable handling of the UART found on 530 Intel Medfield SOC and various other Intel platforms that is not 531 covered by the more generic SERIAL_8250_PCI option. 532 533config SERIAL_8250_PERICOM 534 tristate "Support for Pericom and Acces I/O serial ports" 535 default SERIAL_8250 536 depends on SERIAL_8250 && PCI 537 help 538 Selecting this option will enable handling of the Pericom and Acces 539 I/O UARTs that are not covered by the more generic SERIAL_8250_PCI 540 option. 541 542config SERIAL_8250_PXA 543 tristate "PXA serial port support" 544 depends on SERIAL_8250 545 depends on ARCH_PXA || ARCH_MMP || COMPILE_TEST 546 help 547 If you have a machine based on an Intel XScale PXA2xx CPU you can 548 enable its onboard serial ports by enabling this option. The option is 549 applicable to both devicetree and legacy boards, and early console is 550 part of its support. 551 552config SERIAL_8250_TEGRA 553 tristate "8250 support for Tegra serial ports" 554 default SERIAL_8250 555 depends on SERIAL_8250 556 depends on ARCH_TEGRA || COMPILE_TEST 557 help 558 Select this option if you have machine with an NVIDIA Tegra SoC and 559 wish to enable 8250 serial driver for the Tegra serial interfaces. 560 561config SERIAL_8250_BCM7271 562 tristate "Broadcom 8250 based serial port" 563 depends on SERIAL_8250 && (ARCH_BRCMSTB || COMPILE_TEST) 564 default ARCH_BRCMSTB 565 help 566 If you have a Broadcom STB based board and want to use the 567 enhanced features of the Broadcom 8250 based serial port, 568 including DMA support and high accuracy BAUD rates, say 569 Y to this option. If unsure, say N. 570 571config SERIAL_OF_PLATFORM 572 tristate "Devicetree based probing for 8250 ports" 573 depends on SERIAL_8250 && OF 574 help 575 This option is used for all 8250 compatible serial ports that 576 are probed through devicetree, including Open Firmware based 577 PowerPC systems and embedded systems on architectures using the 578 flattened device tree format. 579