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. (Note that the Cyclades multi serial port driver 19 does not need this driver built in for it to work.) 20 21 To compile this driver as a module, choose M here: the 22 module will be called 8250. 23 [WARNING: Do not compile this driver as a module if you are using 24 non-standard serial ports, since the configuration information will 25 be lost when the driver is unloaded. This limitation may be lifted 26 in the future.] 27 28 BTW1: If you have a mouseman serial mouse which is not recognized by 29 the X window system, try running gpm first. 30 31 BTW2: If you intend to use a software modem (also called Winmodem) 32 under Linux, forget it. These modems are crippled and require 33 proprietary drivers which are only available under Windows. 34 35 Most people will say Y or M here, so that they can use serial mice, 36 modems and similar devices connecting to the standard serial ports. 37 38config SERIAL_8250_DEPRECATED_OPTIONS 39 bool "Support 8250_core.* kernel options (DEPRECATED)" 40 depends on SERIAL_8250 41 default y 42 ---help--- 43 In 3.7 we renamed 8250 to 8250_core by mistake, so now we have to 44 accept kernel parameters in both forms like 8250_core.nr_uarts=4 and 45 8250.nr_uarts=4. We now renamed the module back to 8250, but if 46 anybody noticed in 3.7 and changed their userspace we still have to 47 keep the 8250_core.* options around until they revert the changes 48 they already did. 49 50 If 8250 is built as a module, this adds 8250_core alias instead. 51 52 If you did not notice yet and/or you have userspace from pre-3.7, it 53 is safe (and recommended) to say N here. 54 55config SERIAL_8250_PNP 56 bool "8250/16550 PNP device support" if EXPERT 57 depends on SERIAL_8250 && PNP 58 default y 59 ---help--- 60 This builds standard PNP serial support. You may be able to 61 disable this feature if you only need legacy serial support. 62 63config SERIAL_8250_FINTEK 64 bool "Support for Fintek F81216A LPC to 4 UART RS485 API" 65 depends on SERIAL_8250 66 ---help--- 67 Selecting this option will add support for the RS485 capabilities 68 of the Fintek F81216A LPC to 4 UART. 69 70 If this option is not selected the device will be configured as a 71 standard 16550A serial port. 72 73 If unsure, say N. 74 75config SERIAL_8250_CONSOLE 76 bool "Console on 8250/16550 and compatible serial port" 77 depends on SERIAL_8250=y 78 select SERIAL_CORE_CONSOLE 79 select SERIAL_EARLYCON 80 ---help--- 81 If you say Y here, it will be possible to use a serial port as the 82 system console (the system console is the device which receives all 83 kernel messages and warnings and which allows logins in single user 84 mode). This could be useful if some terminal or printer is connected 85 to that serial port. 86 87 Even if you say Y here, the currently visible virtual console 88 (/dev/tty0) will still be used as the system console by default, but 89 you can alter that using a kernel command line option such as 90 "console=ttyS1". (Try "man bootparam" or see the documentation of 91 your boot loader (grub or lilo or loadlin) about how to pass options 92 to the kernel at boot time.) 93 94 If you don't have a VGA card installed and you say Y here, the 95 kernel will automatically use the first serial line, /dev/ttyS0, as 96 system console. 97 98 You can set that using a kernel command line option such as 99 "console=uart8250,io,0x3f8,9600n8" 100 "console=uart8250,mmio,0xff5e0000,115200n8". 101 and it will switch to normal serial console when the corresponding 102 port is ready. 103 "earlycon=uart8250,io,0x3f8,9600n8" 104 "earlycon=uart8250,mmio,0xff5e0000,115200n8". 105 it will not only setup early console. 106 107 If unsure, say N. 108 109config SERIAL_8250_GSC 110 tristate 111 depends on SERIAL_8250 && GSC 112 default SERIAL_8250 113 114config SERIAL_8250_DMA 115 bool "DMA support for 16550 compatible UART controllers" if EXPERT 116 depends on SERIAL_8250 && DMADEVICES=y 117 default SERIAL_8250 118 help 119 This builds DMA support that can be used with 8250/16650 120 compatible UART controllers that support DMA signaling. 121 122config SERIAL_8250_PCI 123 tristate "8250/16550 PCI device support" 124 depends on SERIAL_8250 && PCI 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 default SERIAL_8250 137 help 138 This builds support for XR17C1xx, XR17V3xx and some Commtech 139 422x PCIe serial cards that are not covered by the more generic 140 SERIAL_8250_PCI option. 141 142config SERIAL_8250_HP300 143 tristate 144 depends on SERIAL_8250 && HP300 145 default SERIAL_8250 146 147config SERIAL_8250_CS 148 tristate "8250/16550 PCMCIA device support" 149 depends on PCMCIA && SERIAL_8250 150 ---help--- 151 Say Y here to enable support for 16-bit PCMCIA serial devices, 152 including serial port cards, modems, and the modem functions of 153 multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are 154 credit-card size devices often used with laptops.) 155 156 To compile this driver as a module, choose M here: the 157 module will be called serial_cs. 158 159 If unsure, say N. 160 161config SERIAL_8250_MEN_MCB 162 tristate "MEN MCB UART device support" 163 depends on MCB && SERIAL_8250 164 help 165 This enables support for FPGA based UARTs found on many MEN 166 boards. This driver enables support for the 16z025, 16z057 167 and 16z125 UARTs. 168 169 To compile this driver as a module, chose M here: the 170 module will be called 8250_men_mcb. 171 172 173config SERIAL_8250_NR_UARTS 174 int "Maximum number of 8250/16550 serial ports" 175 depends on SERIAL_8250 176 default "4" 177 help 178 Set this to the number of serial ports you want the driver 179 to support. This includes any ports discovered via ACPI or 180 PCI enumeration and any ports that may be added at run-time 181 via hot-plug, or any ISA multi-port serial cards. 182 183config SERIAL_8250_RUNTIME_UARTS 184 int "Number of 8250/16550 serial ports to register at runtime" 185 depends on SERIAL_8250 186 range 0 SERIAL_8250_NR_UARTS 187 default "4" 188 help 189 Set this to the maximum number of serial ports you want 190 the kernel to register at boot time. This can be overridden 191 with the module parameter "nr_uarts", or boot-time parameter 192 8250.nr_uarts 193 194config SERIAL_8250_EXTENDED 195 bool "Extended 8250/16550 serial driver options" 196 depends on SERIAL_8250 197 help 198 If you wish to use any non-standard features of the standard "dumb" 199 driver, say Y here. This includes HUB6 support, shared serial 200 interrupts, special multiport support, support for more than the 201 four COM 1/2/3/4 boards, etc. 202 203 Note that the answer to this question won't directly affect the 204 kernel: saying N will just cause the configurator to skip all 205 the questions about serial driver options. If unsure, say N. 206 207config SERIAL_8250_MANY_PORTS 208 bool "Support more than 4 legacy serial ports" 209 depends on SERIAL_8250_EXTENDED && !IA64 210 help 211 Say Y here if you have dumb serial boards other than the four 212 standard COM 1/2/3/4 ports. This may happen if you have an AST 213 FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available 214 from <http://www.tldp.org/docs.html#howto>), or other custom 215 serial port hardware which acts similar to standard serial port 216 hardware. If you only use the standard COM 1/2/3/4 ports, you can 217 say N here to save some memory. You can also say Y if you have an 218 "intelligent" multiport card such as Cyclades, Digiboards, etc. 219 220# 221# Multi-port serial cards 222# 223 224config SERIAL_8250_FOURPORT 225 tristate "Support Fourport cards" 226 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 227 help 228 Say Y here if you have an AST FourPort serial board. 229 230 To compile this driver as a module, choose M here: the module 231 will be called 8250_fourport. 232 233config SERIAL_8250_ACCENT 234 tristate "Support Accent cards" 235 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 236 help 237 Say Y here if you have an Accent Async serial board. 238 239 To compile this driver as a module, choose M here: the module 240 will be called 8250_accent. 241 242config SERIAL_8250_ASPEED_VUART 243 tristate "Aspeed Virtual UART" 244 depends on SERIAL_8250 245 depends on OF 246 help 247 If you want to use the virtual UART (VUART) device on Aspeed 248 BMC platforms, enable this option. This enables the 16550A- 249 compatible device on the local LPC bus, giving a UART device 250 with no physical RS232 connections. 251 252config SERIAL_8250_BOCA 253 tristate "Support Boca cards" 254 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 255 help 256 Say Y here if you have a Boca serial board. Please read the Boca 257 mini-HOWTO, available from <http://www.tldp.org/docs.html#howto> 258 259 To compile this driver as a module, choose M here: the module 260 will be called 8250_boca. 261 262config SERIAL_8250_EXAR_ST16C554 263 tristate "Support Exar ST16C554/554D Quad UART" 264 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 265 help 266 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are 267 tinkering with your Envoy TU301, or have a machine with this UART, 268 say Y here. 269 270 To compile this driver as a module, choose M here: the module 271 will be called 8250_exar_st16c554. 272 273config SERIAL_8250_HUB6 274 tristate "Support Hub6 cards" 275 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 276 help 277 Say Y here if you have a HUB6 serial board. 278 279 To compile this driver as a module, choose M here: the module 280 will be called 8250_hub6. 281 282# 283# Misc. options/drivers. 284# 285 286config SERIAL_8250_SHARE_IRQ 287 bool "Support for sharing serial interrupts" 288 depends on SERIAL_8250_EXTENDED 289 help 290 Some serial boards have hardware support which allows multiple dumb 291 serial ports on the same board to share a single IRQ. To enable 292 support for this in the serial driver, say Y here. 293 294config SERIAL_8250_DETECT_IRQ 295 bool "Autodetect IRQ on standard ports (unsafe)" 296 depends on SERIAL_8250_EXTENDED 297 help 298 Say Y here if you want the kernel to try to guess which IRQ 299 to use for your serial port. 300 301 This is considered unsafe; it is far better to configure the IRQ in 302 a boot script using the setserial command. 303 304 If unsure, say N. 305 306config SERIAL_8250_RSA 307 bool "Support RSA serial ports" 308 depends on SERIAL_8250_EXTENDED 309 help 310 Say Y here if you have a IODATA RSA-DV II/S ISA card and 311 would like to use its >115kbps speeds. 312 You will need to provide module parameter "probe_rsa", or boot-time 313 parameter 8250.probe_rsa with I/O addresses of this card then. 314 315 If you don't have such card, or if unsure, say N. 316 317config SERIAL_8250_ACORN 318 tristate "Acorn expansion card serial port support" 319 depends on ARCH_ACORN && SERIAL_8250 320 help 321 If you have an Atomwide Serial card or Serial Port card for an Acorn 322 system, say Y to this option. The driver can handle 1, 2, or 3 port 323 cards. If unsure, say N. 324 325config SERIAL_8250_BCM2835AUX 326 tristate "BCM2835 auxiliar mini UART support" 327 depends on ARCH_BCM2835 || COMPILE_TEST 328 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ 329 help 330 Support for the BCM2835 auxiliar mini UART. 331 332 Features and limitations of the UART are 333 Registers are similar to 16650 registers, 334 set bits in the control registers that are unsupported 335 are ignored and read back as 0 336 7/8 bit operation with 1 start and 1 stop bit 337 8 symbols deep fifo for rx and tx 338 SW controlled RTS and SW readable CTS 339 Clock rate derived from system clock 340 Uses 8 times oversampling (compared to 16 times for 16650) 341 Missing break detection (but break generation) 342 Missing framing error detection 343 Missing parity bit 344 Missing receive time-out interrupt 345 Missing DCD, DSR, DTR and RI signals 346 347 If unsure, say N. 348 349config SERIAL_8250_FSL 350 bool 351 depends on SERIAL_8250_CONSOLE 352 default PPC || ARM || ARM64 353 354config SERIAL_8250_DW 355 tristate "Support for Synopsys DesignWare 8250 quirks" 356 depends on SERIAL_8250 357 help 358 Selecting this option will enable handling of the extra features 359 present in the Synopsys DesignWare APB UART. 360 361config SERIAL_8250_EM 362 tristate "Support for Emma Mobile integrated serial port" 363 depends on SERIAL_8250 && ARM && HAVE_CLK 364 help 365 Selecting this option will add support for the integrated serial 366 port hardware found on the Emma Mobile line of processors. 367 If unsure, say N. 368 369config SERIAL_8250_RT288X 370 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support" 371 depends on SERIAL_8250 372 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620 373 help 374 Selecting this option will add support for the alternate register 375 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others. 376 If unsure, say N. 377 378config SERIAL_8250_OMAP 379 tristate "Support for OMAP internal UART (8250 based driver)" 380 depends on SERIAL_8250 && (ARCH_OMAP2PLUS || ARCH_K3) 381 help 382 If you have a machine based on an Texas Instruments OMAP CPU you 383 can enable its onboard serial ports by enabling this option. 384 385 This driver uses ttyS instead of ttyO. 386 387config SERIAL_8250_OMAP_TTYO_FIXUP 388 bool "Replace ttyO with ttyS" 389 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE 390 default y 391 help 392 This option replaces the "console=ttyO" argument with the matching 393 ttyS argument if the user did not specified it on the command line. 394 This ensures that the user can see the kernel output during boot 395 which he wouldn't see otherwise. The getty has still to be configured 396 for ttyS instead of ttyO regardless of this option. 397 This option is intended for people who "automatically" enable this 398 driver without knowing that this driver requires a different console= 399 argument. If you read this, please keep this option disabled and 400 instead update your kernel command line. If you prepare a kernel for a 401 distribution or other kind of larger user base then you probably want 402 to keep this option enabled. Otherwise people might complain about a 403 not booting kernel because the serial console remains silent in case 404 they forgot to update the command line. 405 406config SERIAL_8250_LPC18XX 407 tristate "NXP LPC18xx/43xx serial port support" 408 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST) 409 default ARCH_LPC18XX 410 help 411 If you have a LPC18xx/43xx based board and want to use the 412 serial port, say Y to this option. If unsure, say Y. 413 414config SERIAL_8250_MT6577 415 tristate "Mediatek serial port support" 416 depends on SERIAL_8250 && ARCH_MEDIATEK 417 help 418 If you have a Mediatek based board and want to use the 419 serial port, say Y to this option. If unsure, say N. 420 421config SERIAL_8250_UNIPHIER 422 tristate "Support for UniPhier on-chip UART" 423 depends on SERIAL_8250 424 depends on ARCH_UNIPHIER || COMPILE_TEST 425 help 426 If you have a UniPhier based board and want to use the on-chip 427 serial ports, say Y to this option. If unsure, say N. 428 429config SERIAL_8250_INGENIC 430 tristate "Support for Ingenic SoC serial ports" 431 depends on SERIAL_8250 432 depends on OF_FLATTREE 433 depends on MIPS || COMPILE_TEST 434 help 435 If you have a system using an Ingenic SoC and wish to make use of 436 its UARTs, say Y to this option. If unsure, say N. 437 438config SERIAL_8250_LPSS 439 tristate "Support for serial ports on Intel LPSS platforms" 440 default SERIAL_8250 441 depends on SERIAL_8250 && PCI 442 depends on X86 || COMPILE_TEST 443 select DW_DMAC_CORE if SERIAL_8250_DMA 444 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS) 445 select RATIONAL 446 help 447 Selecting this option will enable handling of the extra features 448 present on the UART found on various Intel platforms such as: 449 - Intel Baytrail SoC 450 - Intel Braswell SoC 451 - Intel Quark X1000 SoC 452 453config SERIAL_8250_MID 454 tristate "Support for serial ports on Intel MID platforms" 455 default SERIAL_8250 456 depends on SERIAL_8250 && PCI 457 depends on X86 || COMPILE_TEST 458 select HSU_DMA if SERIAL_8250_DMA 459 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID) 460 select RATIONAL 461 help 462 Selecting this option will enable handling of the extra features 463 present on the UART found on Intel Medfield SOC and various other 464 Intel platforms. 465 466config SERIAL_8250_MOXA 467 tristate "MOXA SmartIO MUE support" 468 depends on SERIAL_8250 && PCI 469 help 470 Say Y here if you have a Moxa SmartIO MUE multiport serial card. 471 If unsure, say N. 472 473 This driver can also be built as a module. The module will be called 474 8250_moxa. If you want to do that, say M here. 475 476config SERIAL_8250_PXA 477 tristate "PXA serial port support" 478 depends on SERIAL_8250 479 depends on ARCH_PXA || ARCH_MMP 480 help 481 If you have a machine based on an Intel XScale PXA2xx CPU you can 482 enable its onboard serial ports by enabling this option. The option is 483 applicable to both devicetree and legacy boards, and early console is 484 part of its support. 485 486config SERIAL_OF_PLATFORM 487 tristate "Devicetree based probing for 8250 ports" 488 depends on SERIAL_8250 && OF 489 help 490 This option is used for all 8250 compatible serial ports that 491 are probed through devicetree, including Open Firmware based 492 PowerPC systems and embedded systems on architectures using the 493 flattened device tree format. 494