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 default SERIAL_8250 153 help 154 This builds support for XR17C1xx, XR17V3xx and some Commtech 155 422x PCIe serial cards that are not covered by the more generic 156 SERIAL_8250_PCI option. 157 158config SERIAL_8250_HP300 159 tristate 160 depends on SERIAL_8250 && HP300 161 default SERIAL_8250 162 163config SERIAL_8250_CS 164 tristate "8250/16550 PCMCIA device support" 165 depends on PCMCIA && SERIAL_8250 166 help 167 Say Y here to enable support for 16-bit PCMCIA serial devices, 168 including serial port cards, modems, and the modem functions of 169 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are 170 credit-card size devices often used with laptops.) 171 172 To compile this driver as a module, choose M here: the 173 module will be called serial_cs. 174 175 If unsure, say N. 176 177config SERIAL_8250_MEN_MCB 178 tristate "MEN MCB UART device support" 179 depends on MCB && SERIAL_8250 180 help 181 This enables support for FPGA based UARTs found on many MEN 182 boards. This driver enables support for the 16z025, 16z057 183 and 16z125 UARTs. 184 185 To compile this driver as a module, chose M here: the 186 module will be called 8250_men_mcb. 187 188 189config SERIAL_8250_NR_UARTS 190 int "Maximum number of 8250/16550 serial ports" 191 depends on SERIAL_8250 192 default "4" 193 help 194 Set this to the number of serial ports you want the driver 195 to support. This includes any ports discovered via ACPI or 196 PCI enumeration and any ports that may be added at run-time 197 via hot-plug, or any ISA multi-port serial cards. 198 199config SERIAL_8250_RUNTIME_UARTS 200 int "Number of 8250/16550 serial ports to register at runtime" 201 depends on SERIAL_8250 202 range 0 SERIAL_8250_NR_UARTS 203 default "4" 204 help 205 Set this to the maximum number of serial ports you want 206 the kernel to register at boot time. This can be overridden 207 with the module parameter "nr_uarts", or boot-time parameter 208 8250.nr_uarts 209 210config SERIAL_8250_EXTENDED 211 bool "Extended 8250/16550 serial driver options" 212 depends on SERIAL_8250 213 help 214 If you wish to use any non-standard features of the standard "dumb" 215 driver, say Y here. This includes HUB6 support, shared serial 216 interrupts, special multiport support, support for more than the 217 four COM 1/2/3/4 boards, etc. 218 219 Note that the answer to this question won't directly affect the 220 kernel: saying N will just cause the configurator to skip all 221 the questions about serial driver options. If unsure, say N. 222 223config SERIAL_8250_MANY_PORTS 224 bool "Support more than 4 legacy serial ports" 225 depends on SERIAL_8250_EXTENDED && !IA64 226 help 227 Say Y here if you have dumb serial boards other than the four 228 standard COM 1/2/3/4 ports. This may happen if you have an AST 229 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available 230 from <https://www.tldp.org/docs.html#howto>), or other custom 231 serial port hardware which acts similar to standard serial port 232 hardware. If you only use the standard COM 1/2/3/4 ports, you can 233 say N here to save some memory. You can also say Y if you have an 234 "intelligent" multiport card such as Digiboards, etc. 235 236# 237# Multi-port serial cards 238# 239 240config SERIAL_8250_FOURPORT 241 tristate "Support Fourport cards" 242 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 243 help 244 Say Y here if you have an AST FourPort serial board. 245 246 To compile this driver as a module, choose M here: the module 247 will be called 8250_fourport. 248 249config SERIAL_8250_ACCENT 250 tristate "Support Accent cards" 251 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 252 help 253 Say Y here if you have an Accent Async serial board. 254 255 To compile this driver as a module, choose M here: the module 256 will be called 8250_accent. 257 258config SERIAL_8250_ASPEED_VUART 259 tristate "Aspeed Virtual UART" 260 depends on SERIAL_8250 261 depends on OF 262 depends on MFD_SYSCON 263 depends on ARCH_ASPEED || COMPILE_TEST 264 select REGMAP 265 help 266 If you want to use the virtual UART (VUART) device on Aspeed 267 BMC platforms, enable this option. This enables the 16550A- 268 compatible device on the local LPC bus, giving a UART device 269 with no physical RS232 connections. 270 271config SERIAL_8250_BOCA 272 tristate "Support Boca cards" 273 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 274 help 275 Say Y here if you have a Boca serial board. Please read the Boca 276 mini-HOWTO, available from <https://www.tldp.org/docs.html#howto> 277 278 To compile this driver as a module, choose M here: the module 279 will be called 8250_boca. 280 281config SERIAL_8250_EXAR_ST16C554 282 tristate "Support Exar ST16C554/554D Quad UART" 283 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 284 help 285 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are 286 tinkering with your Envoy TU301, or have a machine with this UART, 287 say Y here. 288 289 To compile this driver as a module, choose M here: the module 290 will be called 8250_exar_st16c554. 291 292config SERIAL_8250_HUB6 293 tristate "Support Hub6 cards" 294 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 295 help 296 Say Y here if you have a HUB6 serial board. 297 298 To compile this driver as a module, choose M here: the module 299 will be called 8250_hub6. 300 301config SERIAL_8250_PCI1XXXX 302 tristate "Microchip 8250 based serial port" 303 depends on SERIAL_8250 && PCI 304 select SERIAL_8250_PCILIB 305 help 306 Select this option if you have a setup with Microchip PCIe 307 Switch with serial port enabled and wish to enable 8250 308 serial driver for the serial interface. This driver support 309 will ensure to support baud rates upto 1.5Mpbs. 310 311# 312# Misc. options/drivers. 313# 314 315config SERIAL_8250_SHARE_IRQ 316 bool "Support for sharing serial interrupts" 317 depends on SERIAL_8250_EXTENDED 318 help 319 Some serial boards have hardware support which allows multiple dumb 320 serial ports on the same board to share a single IRQ. To enable 321 support for this in the serial driver, say Y here. 322 323config SERIAL_8250_DETECT_IRQ 324 bool "Autodetect IRQ on standard ports (unsafe)" 325 depends on SERIAL_8250_EXTENDED 326 help 327 Say Y here if you want the kernel to try to guess which IRQ 328 to use for your serial port. 329 330 This is considered unsafe; it is far better to configure the IRQ in 331 a boot script using the setserial command. 332 333 If unsure, say N. 334 335config SERIAL_8250_RSA 336 bool "Support RSA serial ports" 337 depends on SERIAL_8250_EXTENDED 338 help 339 Say Y here if you have a IODATA RSA-DV II/S ISA card and 340 would like to use its >115kbps speeds. 341 You will need to provide module parameter "probe_rsa", or boot-time 342 parameter 8250.probe_rsa with I/O addresses of this card then. 343 344 If you don't have such card, or if unsure, say N. 345 346config SERIAL_8250_DWLIB 347 bool 348 349config SERIAL_8250_ACORN 350 tristate "Acorn expansion card serial port support" 351 depends on ARCH_ACORN && SERIAL_8250 352 help 353 If you have an Atomwide Serial card or Serial Port card for an Acorn 354 system, say Y to this option. The driver can handle 1, 2, or 3 port 355 cards. If unsure, say N. 356 357config SERIAL_8250_BCM2835AUX 358 tristate "BCM2835 auxiliar mini UART support" 359 depends on ARCH_BCM2835 || COMPILE_TEST 360 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ 361 help 362 Support for the BCM2835 auxiliar mini UART. 363 364 Features and limitations of the UART are 365 Registers are similar to 16650 registers, 366 set bits in the control registers that are unsupported 367 are ignored and read back as 0 368 7/8 bit operation with 1 start and 1 stop bit 369 8 symbols deep fifo for rx and tx 370 SW controlled RTS and SW readable CTS 371 Clock rate derived from system clock 372 Uses 8 times oversampling (compared to 16 times for 16650) 373 Missing break detection (but break generation) 374 Missing framing error detection 375 Missing parity bit 376 Missing receive time-out interrupt 377 Missing DCD, DSR, DTR and RI signals 378 379 If unsure, say N. 380 381config SERIAL_8250_FSL 382 tristate "Freescale 16550 UART support" if COMPILE_TEST && !(PPC || ARM || ARM64) 383 depends on SERIAL_8250 384 default SERIAL_8250 if PPC || ARM || ARM64 385 help 386 Selecting this option enables a workaround for a break-detection 387 erratum for Freescale 16550 UARTs in the 8250 driver. It also 388 enables support for ACPI enumeration. 389 390config SERIAL_8250_DFL 391 tristate "DFL bus driver for Altera 16550 UART" 392 depends on SERIAL_8250 && FPGA_DFL 393 help 394 This option enables support for a Device Feature List (DFL) bus 395 driver for the Altera 16550 UART. One or more Altera 16550 UARTs 396 can be instantiated in a FPGA and then be discovered during 397 enumeration of the DFL bus. 398 399 To compile this driver as a module, chose M here: the 400 module will be called 8250_dfl. 401 402config SERIAL_8250_DW 403 tristate "Support for Synopsys DesignWare 8250 quirks" 404 depends on SERIAL_8250 405 select SERIAL_8250_DWLIB 406 help 407 Selecting this option will enable handling of the extra features 408 present in the Synopsys DesignWare APB UART. 409 410config SERIAL_8250_EM 411 tristate "Support for Emma Mobile integrated serial port" 412 depends on SERIAL_8250 && HAVE_CLK 413 depends on ARCH_RENESAS || COMPILE_TEST 414 help 415 Selecting this option will add support for the integrated serial 416 port hardware found on the Emma Mobile line of processors. 417 If unsure, say N. 418 419config SERIAL_8250_IOC3 420 tristate "SGI IOC3 8250 UART support" 421 depends on SERIAL_8250 422 depends on SGI_MFD_IOC3 || COMPILE_TEST 423 select SERIAL_8250_EXTENDED 424 select SERIAL_8250_SHARE_IRQ 425 help 426 Enable this if you have a SGI Origin or Octane machine. This module 427 provides basic serial support by directly driving the UART chip 428 behind the IOC3 device on those systems. Maximum baud speed is 429 38400bps using this driver. 430 431config SERIAL_8250_RT288X 432 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support" 433 depends on SERIAL_8250 434 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620 435 help 436 Selecting this option will add support for the alternate register 437 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others. 438 If unsure, say N. 439 440config SERIAL_8250_OMAP 441 tristate "Support for OMAP internal UART (8250 based driver)" 442 depends on SERIAL_8250 443 depends on ARCH_OMAP2PLUS || ARCH_K3 || COMPILE_TEST 444 help 445 If you have a machine based on an Texas Instruments OMAP CPU you 446 can enable its onboard serial ports by enabling this option. 447 448 This driver uses ttyS instead of ttyO. 449 450config SERIAL_8250_OMAP_TTYO_FIXUP 451 bool "Replace ttyO with ttyS" 452 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE 453 default y 454 help 455 This option replaces the "console=ttyO" argument with the matching 456 ttyS argument if the user did not specified it on the command line. 457 This ensures that the user can see the kernel output during boot 458 which he wouldn't see otherwise. The getty has still to be configured 459 for ttyS instead of ttyO regardless of this option. 460 This option is intended for people who "automatically" enable this 461 driver without knowing that this driver requires a different console= 462 argument. If you read this, please keep this option disabled and 463 instead update your kernel command line. If you prepare a kernel for a 464 distribution or other kind of larger user base then you probably want 465 to keep this option enabled. Otherwise people might complain about a 466 not booting kernel because the serial console remains silent in case 467 they forgot to update the command line. 468 469config SERIAL_8250_LPC18XX 470 tristate "NXP LPC18xx/43xx serial port support" 471 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST) 472 default ARCH_LPC18XX 473 help 474 If you have a LPC18xx/43xx based board and want to use the 475 serial port, say Y to this option. If unsure, say Y. 476 477config SERIAL_8250_MT6577 478 tristate "Mediatek serial port support" 479 depends on SERIAL_8250 480 depends on ARCH_MEDIATEK || COMPILE_TEST 481 help 482 If you have a Mediatek based board and want to use the 483 serial port, say Y to this option. If unsure, say N. 484 485config SERIAL_8250_UNIPHIER 486 tristate "Support for UniPhier on-chip UART" 487 depends on SERIAL_8250 488 depends on ARCH_UNIPHIER || COMPILE_TEST 489 help 490 If you have a UniPhier based board and want to use the on-chip 491 serial ports, say Y to this option. If unsure, say N. 492 493config SERIAL_8250_INGENIC 494 tristate "Support for Ingenic SoC serial ports" 495 depends on SERIAL_8250 496 depends on OF_FLATTREE 497 depends on MIPS || COMPILE_TEST 498 help 499 If you have a system using an Ingenic SoC and wish to make use of 500 its UARTs, say Y to this option. If unsure, say N. 501 502config SERIAL_8250_LPSS 503 tristate "Support for serial ports on Intel LPSS platforms" 504 default SERIAL_8250 505 depends on SERIAL_8250 && PCI 506 depends on X86 || COMPILE_TEST 507 select SERIAL_8250_DWLIB 508 select DW_DMAC_CORE if SERIAL_8250_DMA 509 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS) 510 select RATIONAL 511 help 512 Selecting this option will enable handling of the UART found on 513 various Intel platforms such as: 514 - Intel Baytrail SoC 515 - Intel Braswell SoC 516 - Intel Quark X1000 SoC 517 that are not covered by the more generic SERIAL_8250_PCI option. 518 519config SERIAL_8250_MID 520 tristate "Support for serial ports on Intel MID platforms" 521 default SERIAL_8250 522 depends on SERIAL_8250 && PCI 523 depends on X86 || COMPILE_TEST 524 select HSU_DMA if SERIAL_8250_DMA 525 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID) 526 select RATIONAL 527 help 528 Selecting this option will enable handling of the UART found on 529 Intel Medfield SOC and various other Intel platforms that is not 530 covered by the more generic SERIAL_8250_PCI option. 531 532config SERIAL_8250_PERICOM 533 tristate "Support for Pericom and Acces I/O serial ports" 534 default SERIAL_8250 535 depends on SERIAL_8250 && PCI 536 help 537 Selecting this option will enable handling of the Pericom and Acces 538 I/O UARTs that are not covered by the more generic SERIAL_8250_PCI 539 option. 540 541config SERIAL_8250_PXA 542 tristate "PXA serial port support" 543 depends on SERIAL_8250 544 depends on ARCH_PXA || ARCH_MMP || COMPILE_TEST 545 help 546 If you have a machine based on an Intel XScale PXA2xx CPU you can 547 enable its onboard serial ports by enabling this option. The option is 548 applicable to both devicetree and legacy boards, and early console is 549 part of its support. 550 551config SERIAL_8250_TEGRA 552 tristate "8250 support for Tegra serial ports" 553 default SERIAL_8250 554 depends on SERIAL_8250 555 depends on ARCH_TEGRA || COMPILE_TEST 556 help 557 Select this option if you have machine with an NVIDIA Tegra SoC and 558 wish to enable 8250 serial driver for the Tegra serial interfaces. 559 560config SERIAL_8250_BCM7271 561 tristate "Broadcom 8250 based serial port" 562 depends on SERIAL_8250 && (ARCH_BRCMSTB || COMPILE_TEST) 563 default ARCH_BRCMSTB 564 help 565 If you have a Broadcom STB based board and want to use the 566 enhanced features of the Broadcom 8250 based serial port, 567 including DMA support and high accuracy BAUD rates, say 568 Y to this option. If unsure, say N. 569 570config SERIAL_OF_PLATFORM 571 tristate "Devicetree based probing for 8250 ports" 572 depends on SERIAL_8250 && OF 573 help 574 This option is used for all 8250 compatible serial ports that 575 are probed through devicetree, including Open Firmware based 576 PowerPC systems and embedded systems on architectures using the 577 flattened device tree format. 578