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 depends on REGMAP && MFD_SYSCON 247 help 248 If you want to use the virtual UART (VUART) device on Aspeed 249 BMC platforms, enable this option. This enables the 16550A- 250 compatible device on the local LPC bus, giving a UART device 251 with no physical RS232 connections. 252 253config SERIAL_8250_BOCA 254 tristate "Support Boca cards" 255 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 256 help 257 Say Y here if you have a Boca serial board. Please read the Boca 258 mini-HOWTO, available from <http://www.tldp.org/docs.html#howto> 259 260 To compile this driver as a module, choose M here: the module 261 will be called 8250_boca. 262 263config SERIAL_8250_EXAR_ST16C554 264 tristate "Support Exar ST16C554/554D Quad UART" 265 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 266 help 267 The Uplogix Envoy TU301 uses this Exar Quad UART. If you are 268 tinkering with your Envoy TU301, or have a machine with this UART, 269 say Y here. 270 271 To compile this driver as a module, choose M here: the module 272 will be called 8250_exar_st16c554. 273 274config SERIAL_8250_HUB6 275 tristate "Support Hub6 cards" 276 depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS 277 help 278 Say Y here if you have a HUB6 serial board. 279 280 To compile this driver as a module, choose M here: the module 281 will be called 8250_hub6. 282 283# 284# Misc. options/drivers. 285# 286 287config SERIAL_8250_SHARE_IRQ 288 bool "Support for sharing serial interrupts" 289 depends on SERIAL_8250_EXTENDED 290 help 291 Some serial boards have hardware support which allows multiple dumb 292 serial ports on the same board to share a single IRQ. To enable 293 support for this in the serial driver, say Y here. 294 295config SERIAL_8250_DETECT_IRQ 296 bool "Autodetect IRQ on standard ports (unsafe)" 297 depends on SERIAL_8250_EXTENDED 298 help 299 Say Y here if you want the kernel to try to guess which IRQ 300 to use for your serial port. 301 302 This is considered unsafe; it is far better to configure the IRQ in 303 a boot script using the setserial command. 304 305 If unsure, say N. 306 307config SERIAL_8250_RSA 308 bool "Support RSA serial ports" 309 depends on SERIAL_8250_EXTENDED 310 help 311 Say Y here if you have a IODATA RSA-DV II/S ISA card and 312 would like to use its >115kbps speeds. 313 You will need to provide module parameter "probe_rsa", or boot-time 314 parameter 8250.probe_rsa with I/O addresses of this card then. 315 316 If you don't have such card, or if unsure, say N. 317 318config SERIAL_8250_DWLIB 319 bool 320 321config SERIAL_8250_ACORN 322 tristate "Acorn expansion card serial port support" 323 depends on ARCH_ACORN && SERIAL_8250 324 help 325 If you have an Atomwide Serial card or Serial Port card for an Acorn 326 system, say Y to this option. The driver can handle 1, 2, or 3 port 327 cards. If unsure, say N. 328 329config SERIAL_8250_BCM2835AUX 330 tristate "BCM2835 auxiliar mini UART support" 331 depends on ARCH_BCM2835 || COMPILE_TEST 332 depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ 333 help 334 Support for the BCM2835 auxiliar mini UART. 335 336 Features and limitations of the UART are 337 Registers are similar to 16650 registers, 338 set bits in the control registers that are unsupported 339 are ignored and read back as 0 340 7/8 bit operation with 1 start and 1 stop bit 341 8 symbols deep fifo for rx and tx 342 SW controlled RTS and SW readable CTS 343 Clock rate derived from system clock 344 Uses 8 times oversampling (compared to 16 times for 16650) 345 Missing break detection (but break generation) 346 Missing framing error detection 347 Missing parity bit 348 Missing receive time-out interrupt 349 Missing DCD, DSR, DTR and RI signals 350 351 If unsure, say N. 352 353config SERIAL_8250_FSL 354 bool 355 depends on SERIAL_8250_CONSOLE 356 default PPC || ARM || ARM64 357 358config SERIAL_8250_DW 359 tristate "Support for Synopsys DesignWare 8250 quirks" 360 depends on SERIAL_8250 361 select SERIAL_8250_DWLIB 362 help 363 Selecting this option will enable handling of the extra features 364 present in the Synopsys DesignWare APB UART. 365 366config SERIAL_8250_EM 367 tristate "Support for Emma Mobile integrated serial port" 368 depends on SERIAL_8250 && ARM && HAVE_CLK 369 help 370 Selecting this option will add support for the integrated serial 371 port hardware found on the Emma Mobile line of processors. 372 If unsure, say N. 373 374config SERIAL_8250_RT288X 375 bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support" 376 depends on SERIAL_8250 377 default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620 378 help 379 Selecting this option will add support for the alternate register 380 layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others. 381 If unsure, say N. 382 383config SERIAL_8250_OMAP 384 tristate "Support for OMAP internal UART (8250 based driver)" 385 depends on SERIAL_8250 && (ARCH_OMAP2PLUS || ARCH_K3) 386 help 387 If you have a machine based on an Texas Instruments OMAP CPU you 388 can enable its onboard serial ports by enabling this option. 389 390 This driver uses ttyS instead of ttyO. 391 392config SERIAL_8250_OMAP_TTYO_FIXUP 393 bool "Replace ttyO with ttyS" 394 depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE 395 default y 396 help 397 This option replaces the "console=ttyO" argument with the matching 398 ttyS argument if the user did not specified it on the command line. 399 This ensures that the user can see the kernel output during boot 400 which he wouldn't see otherwise. The getty has still to be configured 401 for ttyS instead of ttyO regardless of this option. 402 This option is intended for people who "automatically" enable this 403 driver without knowing that this driver requires a different console= 404 argument. If you read this, please keep this option disabled and 405 instead update your kernel command line. If you prepare a kernel for a 406 distribution or other kind of larger user base then you probably want 407 to keep this option enabled. Otherwise people might complain about a 408 not booting kernel because the serial console remains silent in case 409 they forgot to update the command line. 410 411config SERIAL_8250_LPC18XX 412 tristate "NXP LPC18xx/43xx serial port support" 413 depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST) 414 default ARCH_LPC18XX 415 help 416 If you have a LPC18xx/43xx based board and want to use the 417 serial port, say Y to this option. If unsure, say Y. 418 419config SERIAL_8250_MT6577 420 tristate "Mediatek serial port support" 421 depends on SERIAL_8250 && ARCH_MEDIATEK 422 help 423 If you have a Mediatek based board and want to use the 424 serial port, say Y to this option. If unsure, say N. 425 426config SERIAL_8250_UNIPHIER 427 tristate "Support for UniPhier on-chip UART" 428 depends on SERIAL_8250 429 depends on ARCH_UNIPHIER || COMPILE_TEST 430 help 431 If you have a UniPhier based board and want to use the on-chip 432 serial ports, say Y to this option. If unsure, say N. 433 434config SERIAL_8250_INGENIC 435 tristate "Support for Ingenic SoC serial ports" 436 depends on SERIAL_8250 437 depends on OF_FLATTREE 438 depends on MIPS || COMPILE_TEST 439 help 440 If you have a system using an Ingenic SoC and wish to make use of 441 its UARTs, say Y to this option. If unsure, say N. 442 443config SERIAL_8250_LPSS 444 tristate "Support for serial ports on Intel LPSS platforms" 445 default SERIAL_8250 446 depends on SERIAL_8250 && PCI 447 depends on X86 || COMPILE_TEST 448 select SERIAL_8250_DWLIB 449 select DW_DMAC_CORE if SERIAL_8250_DMA 450 select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS) 451 select RATIONAL 452 help 453 Selecting this option will enable handling of the extra features 454 present on the UART found on various Intel platforms such as: 455 - Intel Baytrail SoC 456 - Intel Braswell SoC 457 - Intel Quark X1000 SoC 458 459config SERIAL_8250_MID 460 tristate "Support for serial ports on Intel MID platforms" 461 default SERIAL_8250 462 depends on SERIAL_8250 && PCI 463 depends on X86 || COMPILE_TEST 464 select HSU_DMA if SERIAL_8250_DMA 465 select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID) 466 select RATIONAL 467 help 468 Selecting this option will enable handling of the extra features 469 present on the UART found on Intel Medfield SOC and various other 470 Intel platforms. 471 472config SERIAL_8250_PXA 473 tristate "PXA serial port support" 474 depends on SERIAL_8250 475 depends on ARCH_PXA || ARCH_MMP 476 help 477 If you have a machine based on an Intel XScale PXA2xx CPU you can 478 enable its onboard serial ports by enabling this option. The option is 479 applicable to both devicetree and legacy boards, and early console is 480 part of its support. 481 482config SERIAL_OF_PLATFORM 483 tristate "Devicetree based probing for 8250 ports" 484 depends on SERIAL_8250 && OF 485 help 486 This option is used for all 8250 compatible serial ports that 487 are probed through devicetree, including Open Firmware based 488 PowerPC systems and embedded systems on architectures using the 489 flattened device tree format. 490