drivers/tty/serial/8250/Kconfig

   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
   7 config 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
  38 config 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
  55 config 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
  63 config SERIAL_8250_16550A_VARIANTS
  64         bool "Support for variants of the 16550A serial port"
  65         depends on SERIAL_8250
  66         default !X86
  67         help
  68           The 8250 driver can probe for many variants of the venerable 16550A
  69           serial port. Doing so takes additional time at boot.
  70
  71           On modern systems, especially those using serial only for a simple
  72           console, you can say N here.
  73
  74 config SERIAL_8250_FINTEK
  75         bool "Support for Fintek F81216A LPC to 4 UART RS485 API"
  76         depends on SERIAL_8250
  77         help
  78           Selecting this option will add support for the RS485 capabilities
  79           of the Fintek F81216A LPC to 4 UART.
  80
  81           If this option is not selected the device will be configured as a
  82           standard 16550A serial port.
  83
  84           If unsure, say N.
  85
  86 config SERIAL_8250_CONSOLE
  87         bool "Console on 8250/16550 and compatible serial port"
  88         depends on SERIAL_8250=y
  89         select SERIAL_CORE_CONSOLE
  90         select SERIAL_EARLYCON
  91         help
  92           If you say Y here, it will be possible to use a serial port as the
  93           system console (the system console is the device which receives all
  94           kernel messages and warnings and which allows logins in single user
  95           mode). This could be useful if some terminal or printer is connected
  96           to that serial port.
  97
  98           Even if you say Y here, the currently visible virtual console
  99           (/dev/tty0) will still be used as the system console by default, but
 100           you can alter that using a kernel command line option such as
 101           "console=ttyS1". (Try "man bootparam" or see the documentation of
 102           your boot loader (grub or lilo or loadlin) about how to pass options
 103           to the kernel at boot time.)
 104
 105           If you don't have a VGA card installed and you say Y here, the
 106           kernel will automatically use the first serial line, /dev/ttyS0, as
 107           system console.
 108
 109           You can set that using a kernel command line option such as
 110           "console=uart8250,io,0x3f8,9600n8"
 111           "console=uart8250,mmio,0xff5e0000,115200n8".
 112           and it will switch to normal serial console when the corresponding
 113           port is ready.
 114           "earlycon=uart8250,io,0x3f8,9600n8"
 115           "earlycon=uart8250,mmio,0xff5e0000,115200n8".
 116           it will not only setup early console.
 117
 118           If unsure, say N.
 119
 120 config SERIAL_8250_GSC
 121         tristate
 122         depends on SERIAL_8250 && GSC
 123         default SERIAL_8250
 124
 125 config SERIAL_8250_DMA
 126         bool "DMA support for 16550 compatible UART controllers" if EXPERT
 127         depends on SERIAL_8250 && DMADEVICES=y
 128         default SERIAL_8250
 129         help
 130           This builds DMA support that can be used with 8250/16650
 131           compatible UART controllers that support DMA signaling.
 132
 133 config SERIAL_8250_PCI
 134         tristate "8250/16550 PCI device support"
 135         depends on SERIAL_8250 && PCI
 136         default SERIAL_8250
 137         help
 138           This builds standard PCI serial support. You may be able to
 139           disable this feature if you only need legacy serial support.
 140           Saves about 9K.
 141           Note that serial ports on NetMos 9835 Multi-I/O cards are handled
 142           by the parport_serial driver, enabled with CONFIG_PARPORT_SERIAL.
 143
 144 config SERIAL_8250_EXAR
 145         tristate "8250/16550 Exar/Commtech PCI/PCIe device support"
 146         depends on SERIAL_8250_PCI
 147         default SERIAL_8250
 148         help
 149           This builds support for XR17C1xx, XR17V3xx and some Commtech
 150           422x PCIe serial cards that are not covered by the more generic
 151           SERIAL_8250_PCI option.
 152
 153 config SERIAL_8250_HP300
 154         tristate
 155         depends on SERIAL_8250 && HP300
 156         default SERIAL_8250
 157
 158 config SERIAL_8250_CS
 159         tristate "8250/16550 PCMCIA device support"
 160         depends on PCMCIA && SERIAL_8250
 161         help
 162           Say Y here to enable support for 16-bit PCMCIA serial devices,
 163           including serial port cards, modems, and the modem functions of
 164           multi-function Ethernet/modem cards. (PCMCIA- or PC-cards are
 165           credit-card size devices often used with laptops.)
 166
 167           To compile this driver as a module, choose M here: the
 168           module will be called serial_cs.
 169
 170           If unsure, say N.
 171
 172 config SERIAL_8250_MEN_MCB
 173         tristate "MEN MCB UART device support"
 174         depends on MCB && SERIAL_8250
 175         help
 176           This enables support for FPGA based UARTs found on many MEN
 177           boards. This driver enables support for the 16z025, 16z057
 178           and 16z125 UARTs.
 179
 180           To compile this driver as a module, chose M here: the
 181           module will be called 8250_men_mcb.
 182
 183
 184 config SERIAL_8250_NR_UARTS
 185         int "Maximum number of 8250/16550 serial ports"
 186         depends on SERIAL_8250
 187         default "4"
 188         help
 189           Set this to the number of serial ports you want the driver
 190           to support.  This includes any ports discovered via ACPI or
 191           PCI enumeration and any ports that may be added at run-time
 192           via hot-plug, or any ISA multi-port serial cards.
 193
 194 config SERIAL_8250_RUNTIME_UARTS
 195         int "Number of 8250/16550 serial ports to register at runtime"
 196         depends on SERIAL_8250
 197         range 0 SERIAL_8250_NR_UARTS
 198         default "4"
 199         help
 200           Set this to the maximum number of serial ports you want
 201           the kernel to register at boot time.  This can be overridden
 202           with the module parameter "nr_uarts", or boot-time parameter
 203           8250.nr_uarts
 204
 205 config SERIAL_8250_EXTENDED
 206         bool "Extended 8250/16550 serial driver options"
 207         depends on SERIAL_8250
 208         help
 209           If you wish to use any non-standard features of the standard "dumb"
 210           driver, say Y here. This includes HUB6 support, shared serial
 211           interrupts, special multiport support, support for more than the
 212           four COM 1/2/3/4 boards, etc.
 213
 214           Note that the answer to this question won't directly affect the
 215           kernel: saying N will just cause the configurator to skip all
 216           the questions about serial driver options. If unsure, say N.
 217
 218 config SERIAL_8250_MANY_PORTS
 219         bool "Support more than 4 legacy serial ports"
 220         depends on SERIAL_8250_EXTENDED && !IA64
 221         help
 222           Say Y here if you have dumb serial boards other than the four
 223           standard COM 1/2/3/4 ports. This may happen if you have an AST
 224           FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
 225           from <https://www.tldp.org/docs.html#howto>), or other custom
 226           serial port hardware which acts similar to standard serial port
 227           hardware. If you only use the standard COM 1/2/3/4 ports, you can
 228           say N here to save some memory. You can also say Y if you have an
 229           "intelligent" multiport card such as Cyclades, Digiboards, etc.
 230
 231 #
 232 # Multi-port serial cards
 233 #
 234
 235 config SERIAL_8250_FOURPORT
 236         tristate "Support Fourport cards"
 237         depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
 238         help
 239           Say Y here if you have an AST FourPort serial board.
 240
 241           To compile this driver as a module, choose M here: the module
 242           will be called 8250_fourport.
 243
 244 config SERIAL_8250_ACCENT
 245         tristate "Support Accent cards"
 246         depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
 247         help
 248           Say Y here if you have an Accent Async serial board.
 249
 250           To compile this driver as a module, choose M here: the module
 251           will be called 8250_accent.
 252
 253 config SERIAL_8250_ASPEED_VUART
 254         tristate "Aspeed Virtual UART"
 255         depends on SERIAL_8250
 256         depends on OF
 257         depends on REGMAP && MFD_SYSCON
 258         help
 259           If you want to use the virtual UART (VUART) device on Aspeed
 260           BMC platforms, enable this option. This enables the 16550A-
 261           compatible device on the local LPC bus, giving a UART device
 262           with no physical RS232 connections.
 263
 264 config SERIAL_8250_BOCA
 265         tristate "Support Boca cards"
 266         depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
 267         help
 268           Say Y here if you have a Boca serial board.  Please read the Boca
 269           mini-HOWTO, available from <https://www.tldp.org/docs.html#howto>
 270
 271           To compile this driver as a module, choose M here: the module
 272           will be called 8250_boca.
 273
 274 config SERIAL_8250_EXAR_ST16C554
 275         tristate "Support Exar ST16C554/554D Quad UART"
 276         depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
 277         help
 278           The Uplogix Envoy TU301 uses this Exar Quad UART.  If you are
 279           tinkering with your Envoy TU301, or have a machine with this UART,
 280           say Y here.
 281
 282           To compile this driver as a module, choose M here: the module
 283           will be called 8250_exar_st16c554.
 284
 285 config SERIAL_8250_HUB6
 286         tristate "Support Hub6 cards"
 287         depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
 288         help
 289           Say Y here if you have a HUB6 serial board.
 290
 291           To compile this driver as a module, choose M here: the module
 292           will be called 8250_hub6.
 293
 294 #
 295 # Misc. options/drivers.
 296 #
 297
 298 config SERIAL_8250_SHARE_IRQ
 299         bool "Support for sharing serial interrupts"
 300         depends on SERIAL_8250_EXTENDED
 301         help
 302           Some serial boards have hardware support which allows multiple dumb
 303           serial ports on the same board to share a single IRQ. To enable
 304           support for this in the serial driver, say Y here.
 305
 306 config SERIAL_8250_DETECT_IRQ
 307         bool "Autodetect IRQ on standard ports (unsafe)"
 308         depends on SERIAL_8250_EXTENDED
 309         help
 310           Say Y here if you want the kernel to try to guess which IRQ
 311           to use for your serial port.
 312
 313           This is considered unsafe; it is far better to configure the IRQ in
 314           a boot script using the setserial command.
 315
 316           If unsure, say N.
 317
 318 config SERIAL_8250_RSA
 319         bool "Support RSA serial ports"
 320         depends on SERIAL_8250_EXTENDED
 321         help
 322           Say Y here if you have a IODATA RSA-DV II/S ISA card and
 323           would like to use its >115kbps speeds.
 324           You will need to provide module parameter "probe_rsa", or boot-time
 325           parameter 8250.probe_rsa with I/O addresses of this card then.
 326
 327           If you don't have such card, or if unsure, say N.
 328
 329 config SERIAL_8250_DWLIB
 330         bool
 331
 332 config SERIAL_8250_ACORN
 333         tristate "Acorn expansion card serial port support"
 334         depends on ARCH_ACORN && SERIAL_8250
 335         help
 336           If you have an Atomwide Serial card or Serial Port card for an Acorn
 337           system, say Y to this option.  The driver can handle 1, 2, or 3 port
 338           cards.  If unsure, say N.
 339
 340 config SERIAL_8250_BCM2835AUX
 341         tristate "BCM2835 auxiliar mini UART support"
 342         depends on ARCH_BCM2835 || COMPILE_TEST
 343         depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ
 344         help
 345           Support for the BCM2835 auxiliar mini UART.
 346
 347           Features and limitations of the UART are
 348             Registers are similar to 16650 registers,
 349               set bits in the control registers that are unsupported
 350               are ignored and read back as 0
 351             7/8 bit operation with 1 start and 1 stop bit
 352             8 symbols deep fifo for rx and tx
 353             SW controlled RTS and SW readable CTS
 354             Clock rate derived from system clock
 355             Uses 8 times oversampling (compared to 16 times for 16650)
 356             Missing break detection (but break generation)
 357             Missing framing error detection
 358             Missing parity bit
 359             Missing receive time-out interrupt
 360             Missing DCD, DSR, DTR and RI signals
 361
 362           If unsure, say N.
 363
 364 config SERIAL_8250_FSL
 365         bool
 366         depends on SERIAL_8250_CONSOLE
 367         default PPC || ARM || ARM64
 368
 369 config SERIAL_8250_DW
 370         tristate "Support for Synopsys DesignWare 8250 quirks"
 371         depends on SERIAL_8250
 372         select SERIAL_8250_DWLIB
 373         help
 374           Selecting this option will enable handling of the extra features
 375           present in the Synopsys DesignWare APB UART.
 376
 377 config SERIAL_8250_EM
 378         tristate "Support for Emma Mobile integrated serial port"
 379         depends on SERIAL_8250 && ARM && HAVE_CLK
 380         help
 381           Selecting this option will add support for the integrated serial
 382           port hardware found on the Emma Mobile line of processors.
 383           If unsure, say N.
 384
 385 config SERIAL_8250_IOC3
 386         tristate "SGI IOC3 8250 UART support"
 387         depends on SGI_MFD_IOC3 && SERIAL_8250
 388         select SERIAL_8250_EXTENDED
 389         select SERIAL_8250_SHARE_IRQ
 390         help
 391           Enable this if you have a SGI Origin or Octane machine. This module
 392           provides basic serial support by directly driving the UART chip
 393           behind the IOC3 device on those systems.  Maximum baud speed is
 394           38400bps using this driver.
 395
 396 config SERIAL_8250_RT288X
 397         bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
 398         depends on SERIAL_8250
 399         default y if MIPS_ALCHEMY || SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620
 400         help
 401           Selecting this option will add support for the alternate register
 402           layout used by Ralink RT288x/RT305x, Alchemy Au1xxx, and some others.
 403           If unsure, say N.
 404
 405 config SERIAL_8250_OMAP
 406         tristate "Support for OMAP internal UART (8250 based driver)"
 407         depends on SERIAL_8250 && (ARCH_OMAP2PLUS || ARCH_K3)
 408         help
 409           If you have a machine based on an Texas Instruments OMAP CPU you
 410           can enable its onboard serial ports by enabling this option.
 411
 412           This driver uses ttyS instead of ttyO.
 413
 414 config SERIAL_8250_OMAP_TTYO_FIXUP
 415         bool "Replace ttyO with ttyS"
 416         depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
 417         default y
 418         help
 419           This option replaces the "console=ttyO" argument with the matching
 420           ttyS argument if the user did not specified it on the command line.
 421           This ensures that the user can see the kernel output during boot
 422           which he wouldn't see otherwise. The getty has still to be configured
 423           for ttyS instead of ttyO regardless of this option.
 424           This option is intended for people who "automatically" enable this
 425           driver without knowing that this driver requires a different console=
 426           argument. If you read this, please keep this option disabled and
 427           instead update your kernel command line. If you prepare a kernel for a
 428           distribution or other kind of larger user base then you probably want
 429           to keep this option enabled. Otherwise people might complain about a
 430           not booting kernel because the serial console remains silent in case
 431           they forgot to update the command line.
 432
 433 config SERIAL_8250_LPC18XX
 434         tristate "NXP LPC18xx/43xx serial port support"
 435         depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)
 436         default ARCH_LPC18XX
 437         help
 438           If you have a LPC18xx/43xx based board and want to use the
 439           serial port, say Y to this option. If unsure, say Y.
 440
 441 config SERIAL_8250_MT6577
 442         tristate "Mediatek serial port support"
 443         depends on SERIAL_8250 && ARCH_MEDIATEK
 444         help
 445           If you have a Mediatek based board and want to use the
 446           serial port, say Y to this option. If unsure, say N.
 447
 448 config SERIAL_8250_UNIPHIER
 449         tristate "Support for UniPhier on-chip UART"
 450         depends on SERIAL_8250
 451         depends on ARCH_UNIPHIER || COMPILE_TEST
 452         help
 453           If you have a UniPhier based board and want to use the on-chip
 454           serial ports, say Y to this option. If unsure, say N.
 455
 456 config SERIAL_8250_INGENIC
 457         tristate "Support for Ingenic SoC serial ports"
 458         depends on SERIAL_8250
 459         depends on OF_FLATTREE
 460         depends on MIPS || COMPILE_TEST
 461         help
 462           If you have a system using an Ingenic SoC and wish to make use of
 463           its UARTs, say Y to this option. If unsure, say N.
 464
 465 config SERIAL_8250_LPSS
 466         tristate "Support for serial ports on Intel LPSS platforms"
 467         default SERIAL_8250
 468         depends on SERIAL_8250 && PCI
 469         depends on X86 || COMPILE_TEST
 470         select SERIAL_8250_DWLIB
 471         select DW_DMAC_CORE if SERIAL_8250_DMA
 472         select DW_DMAC_PCI if (SERIAL_8250_DMA && X86_INTEL_LPSS)
 473         select RATIONAL
 474         help
 475           Selecting this option will enable handling of the extra features
 476           present on the UART found on various Intel platforms such as:
 477             - Intel Baytrail SoC
 478             - Intel Braswell SoC
 479             - Intel Quark X1000 SoC
 480
 481 config SERIAL_8250_MID
 482         tristate "Support for serial ports on Intel MID platforms"
 483         default SERIAL_8250
 484         depends on SERIAL_8250 && PCI
 485         depends on X86 || COMPILE_TEST
 486         select HSU_DMA if SERIAL_8250_DMA
 487         select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
 488         select RATIONAL
 489         help
 490           Selecting this option will enable handling of the extra features
 491           present on the UART found on Intel Medfield SOC and various other
 492           Intel platforms.
 493
 494 config SERIAL_8250_PXA
 495         tristate "PXA serial port support"
 496         depends on SERIAL_8250
 497         depends on ARCH_PXA || ARCH_MMP
 498         help
 499           If you have a machine based on an Intel XScale PXA2xx CPU you can
 500           enable its onboard serial ports by enabling this option. The option is
 501           applicable to both devicetree and legacy boards, and early console is
 502           part of its support.
 503
 504 config SERIAL_8250_TEGRA
 505         tristate "8250 support for Tegra serial ports"
 506         default SERIAL_8250
 507         depends on SERIAL_8250
 508         depends on ARCH_TEGRA || COMPILE_TEST
 509         help
 510           Select this option if you have machine with an NVIDIA Tegra SoC and
 511           wish to enable 8250 serial driver for the Tegra serial interfaces.
 512
 513 config SERIAL_OF_PLATFORM
 514         tristate "Devicetree based probing for 8250 ports"
 515         depends on SERIAL_8250 && OF
 516         help
 517           This option is used for all 8250 compatible serial ports that
 518           are probed through devicetree, including Open Firmware based
 519           PowerPC systems and embedded systems on architectures using the
 520           flattened device tree format.