1# 2# GPIO infrastructure and drivers 3# 4 5config ARCH_HAVE_CUSTOM_GPIO_H 6 bool 7 help 8 Selecting this config option from the architecture Kconfig allows 9 the architecture to provide a custom asm/gpio.h implementation 10 overriding the default implementations. New uses of this are 11 strongly discouraged. 12 13config ARCH_WANT_OPTIONAL_GPIOLIB 14 bool 15 help 16 Select this config option from the architecture Kconfig, if 17 it is possible to use gpiolib on the architecture, but let the 18 user decide whether to actually build it or not. 19 Select this instead of ARCH_REQUIRE_GPIOLIB, if your architecture does 20 not depend on GPIOs being available, but rather let the user 21 decide whether he needs it or not. 22 23config ARCH_REQUIRE_GPIOLIB 24 bool 25 select GPIOLIB 26 help 27 Platforms select gpiolib if they use this infrastructure 28 for all their GPIOs, usually starting with ones integrated 29 into SOC processors. 30 Selecting this from the architecture code will cause the gpiolib 31 code to always get built in. 32 33 34 35menuconfig GPIOLIB 36 bool "GPIO Support" 37 depends on ARCH_WANT_OPTIONAL_GPIOLIB || ARCH_REQUIRE_GPIOLIB 38 select GENERIC_GPIO 39 help 40 This enables GPIO support through the generic GPIO library. 41 You only need to enable this, if you also want to enable 42 one or more of the GPIO drivers below. 43 44 If unsure, say N. 45 46if GPIOLIB 47 48config OF_GPIO 49 def_bool y 50 depends on OF 51 52config GPIO_ACPI 53 def_bool y 54 depends on ACPI 55 56config DEBUG_GPIO 57 bool "Debug GPIO calls" 58 depends on DEBUG_KERNEL 59 help 60 Say Y here to add some extra checks and diagnostics to GPIO calls. 61 These checks help ensure that GPIOs have been properly initialized 62 before they are used, and that sleeping calls are not made from 63 non-sleeping contexts. They can make bitbanged serial protocols 64 slower. The diagnostics help catch the type of setup errors 65 that are most common when setting up new platforms or boards. 66 67config GPIO_SYSFS 68 bool "/sys/class/gpio/... (sysfs interface)" 69 depends on SYSFS && EXPERIMENTAL 70 help 71 Say Y here to add a sysfs interface for GPIOs. 72 73 This is mostly useful to work around omissions in a system's 74 kernel support. Those are common in custom and semicustom 75 hardware assembled using standard kernels with a minimum of 76 custom patches. In those cases, userspace code may import 77 a given GPIO from the kernel, if no kernel driver requested it. 78 79 Kernel drivers may also request that a particular GPIO be 80 exported to userspace; this can be useful when debugging. 81 82config GPIO_GENERIC 83 tristate 84 85# put drivers in the right section, in alphabetical order 86 87config GPIO_DA9052 88 tristate "Dialog DA9052 GPIO" 89 depends on PMIC_DA9052 90 help 91 Say yes here to enable the GPIO driver for the DA9052 chip. 92 93config GPIO_DA9055 94 tristate "Dialog Semiconductor DA9055 GPIO" 95 depends on MFD_DA9055 96 help 97 Say yes here to enable the GPIO driver for the DA9055 chip. 98 99 The Dialog DA9055 PMIC chip has 3 GPIO pins that can be 100 be controller by this driver. 101 102 If driver is built as a module it will be called gpio-da9055. 103 104config GPIO_MAX730X 105 tristate 106 107comment "Memory mapped GPIO drivers:" 108 109config GPIO_CLPS711X 110 def_bool y 111 depends on ARCH_CLPS711X 112 113config GPIO_GENERIC_PLATFORM 114 tristate "Generic memory-mapped GPIO controller support (MMIO platform device)" 115 select GPIO_GENERIC 116 help 117 Say yes here to support basic platform_device memory-mapped GPIO controllers. 118 119config GPIO_IT8761E 120 tristate "IT8761E GPIO support" 121 depends on X86 # unconditional access to IO space. 122 help 123 Say yes here to support GPIO functionality of IT8761E super I/O chip. 124 125config GPIO_EM 126 tristate "Emma Mobile GPIO" 127 depends on ARM 128 help 129 Say yes here to support GPIO on Renesas Emma Mobile SoCs. 130 131config GPIO_EP93XX 132 def_bool y 133 depends on ARCH_EP93XX 134 select GPIO_GENERIC 135 136config GPIO_MM_LANTIQ 137 bool "Lantiq Memory mapped GPIOs" 138 depends on LANTIQ && SOC_XWAY 139 help 140 This enables support for memory mapped GPIOs on the External Bus Unit 141 (EBU) found on Lantiq SoCs. The gpios are output only as they are 142 created by attaching a 16bit latch to the bus. 143 144config GPIO_MPC5200 145 def_bool y 146 depends on PPC_MPC52xx 147 148config GPIO_MPC8XXX 149 bool "MPC512x/MPC8xxx GPIO support" 150 depends on PPC_MPC512x || PPC_MPC831x || PPC_MPC834x || PPC_MPC837x || \ 151 FSL_SOC_BOOKE || PPC_86xx 152 help 153 Say Y here if you're going to use hardware that connects to the 154 MPC512x/831x/834x/837x/8572/8610 GPIOs. 155 156config GPIO_MSM_V1 157 tristate "Qualcomm MSM GPIO v1" 158 depends on GPIOLIB && ARCH_MSM && (ARCH_MSM7X00A || ARCH_MSM7X30 || ARCH_QSD8X50) 159 help 160 Say yes here to support the GPIO interface on ARM v6 based 161 Qualcomm MSM chips. Most of the pins on the MSM can be 162 selected for GPIO, and are controlled by this driver. 163 164config GPIO_MSM_V2 165 tristate "Qualcomm MSM GPIO v2" 166 depends on GPIOLIB && ARCH_MSM 167 help 168 Say yes here to support the GPIO interface on ARM v7 based 169 Qualcomm MSM chips. Most of the pins on the MSM can be 170 selected for GPIO, and are controlled by this driver. 171 172config GPIO_MVEBU 173 def_bool y 174 depends on PLAT_ORION 175 depends on OF 176 select GPIO_GENERIC 177 select GENERIC_IRQ_CHIP 178 179config GPIO_MXC 180 def_bool y 181 depends on ARCH_MXC 182 select GPIO_GENERIC 183 select GENERIC_IRQ_CHIP 184 185config GPIO_MXS 186 def_bool y 187 depends on ARCH_MXS 188 select GPIO_GENERIC 189 select GENERIC_IRQ_CHIP 190 191config GPIO_PL061 192 bool "PrimeCell PL061 GPIO support" 193 depends on ARM && ARM_AMBA 194 select GENERIC_IRQ_CHIP 195 help 196 Say yes here to support the PrimeCell PL061 GPIO device 197 198config GPIO_PXA 199 bool "PXA GPIO support" 200 depends on ARCH_PXA || ARCH_MMP 201 help 202 Say yes here to support the PXA GPIO device 203 204config GPIO_SPEAR_SPICS 205 bool "ST SPEAr13xx SPI Chip Select as GPIO support" 206 depends on PLAT_SPEAR 207 select GENERIC_IRQ_CHIP 208 help 209 Say yes here to support ST SPEAr SPI Chip Select as GPIO device 210 211config GPIO_STA2X11 212 bool "STA2x11/ConneXt GPIO support" 213 depends on MFD_STA2X11 214 select GENERIC_IRQ_CHIP 215 help 216 Say yes here to support the STA2x11/ConneXt GPIO device. 217 The GPIO module has 128 GPIO pins with alternate functions. 218 219config GPIO_TS5500 220 tristate "TS-5500 DIO blocks and compatibles" 221 help 222 This driver supports Digital I/O exposed by pin blocks found on some 223 Technologic Systems platforms. It includes, but is not limited to, 3 224 blocks of the TS-5500: DIO1, DIO2 and the LCD port, and the TS-5600 225 LCD port. 226 227config GPIO_VT8500 228 bool "VIA/Wondermedia SoC GPIO Support" 229 depends on ARCH_VT8500 230 help 231 Say yes here to support the VT8500/WM8505/WM8650 GPIO controller. 232 233config GPIO_XILINX 234 bool "Xilinx GPIO support" 235 depends on PPC_OF || MICROBLAZE 236 help 237 Say yes here to support the Xilinx FPGA GPIO device 238 239config GPIO_VR41XX 240 tristate "NEC VR4100 series General-purpose I/O Uint support" 241 depends on CPU_VR41XX 242 help 243 Say yes here to support the NEC VR4100 series General-purpose I/O Uint 244 245config GPIO_SCH 246 tristate "Intel SCH/TunnelCreek/Centerton GPIO" 247 depends on PCI && X86 248 select MFD_CORE 249 select LPC_SCH 250 help 251 Say yes here to support GPIO interface on Intel Poulsbo SCH, 252 Intel Tunnel Creek processor or Intel Centerton processor. 253 The Intel SCH contains a total of 14 GPIO pins. Ten GPIOs are 254 powered by the core power rail and are turned off during sleep 255 modes (S3 and higher). The remaining four GPIOs are powered by 256 the Intel SCH suspend power supply. These GPIOs remain 257 active during S3. The suspend powered GPIOs can be used to wake the 258 system from the Suspend-to-RAM state. 259 The Intel Tunnel Creek processor has 5 GPIOs powered by the 260 core power rail and 9 from suspend power supply. 261 The Intel Centerton processor has a total of 30 GPIO pins. 262 Twenty-one are powered by the core power rail and 9 from the 263 suspend power supply. 264 265config GPIO_ICH 266 tristate "Intel ICH GPIO" 267 depends on PCI && X86 268 select MFD_CORE 269 select LPC_ICH 270 help 271 Say yes here to support the GPIO functionality of a number of Intel 272 ICH-based chipsets. Currently supported devices: ICH6, ICH7, ICH8 273 ICH9, ICH10, Series 5/3400 (eg Ibex Peak), Series 6/C200 (eg 274 Cougar Point), NM10 (Tiger Point), and 3100 (Whitmore Lake). 275 276 If unsure, say N. 277 278config GPIO_VX855 279 tristate "VIA VX855/VX875 GPIO" 280 depends on PCI 281 select MFD_CORE 282 select MFD_VX855 283 help 284 Support access to the VX855/VX875 GPIO lines through the gpio library. 285 286 This driver provides common support for accessing the device, 287 additional drivers must be enabled in order to use the 288 functionality of the device. 289 290config GPIO_GE_FPGA 291 bool "GE FPGA based GPIO" 292 depends on GE_FPGA 293 help 294 Support for common GPIO functionality provided on some GE Single Board 295 Computers. 296 297 This driver provides basic support (configure as input or output, read 298 and write pin state) for GPIO implemented in a number of GE single 299 board computers. 300 301comment "I2C GPIO expanders:" 302 303config GPIO_ARIZONA 304 tristate "Wolfson Microelectronics Arizona class devices" 305 depends on MFD_ARIZONA 306 help 307 Support for GPIOs on Wolfson Arizona class devices. 308 309config GPIO_MAX7300 310 tristate "Maxim MAX7300 GPIO expander" 311 depends on I2C 312 select GPIO_MAX730X 313 help 314 GPIO driver for Maxim MAX7301 I2C-based GPIO expander. 315 316config GPIO_MAX732X 317 tristate "MAX7319, MAX7320-7327 I2C Port Expanders" 318 depends on I2C 319 help 320 Say yes here to support the MAX7319, MAX7320-7327 series of I2C 321 Port Expanders. Each IO port on these chips has a fixed role of 322 Input (designated by 'I'), Push-Pull Output ('O'), or Open-Drain 323 Input and Output (designed by 'P'). The combinations are listed 324 below: 325 326 8 bits: max7319 (8I), max7320 (8O), max7321 (8P), 327 max7322 (4I4O), max7323 (4P4O) 328 329 16 bits: max7324 (8I8O), max7325 (8P8O), 330 max7326 (4I12O), max7327 (4P12O) 331 332 Board setup code must specify the model to use, and the start 333 number for these GPIOs. 334 335config GPIO_MAX732X_IRQ 336 bool "Interrupt controller support for MAX732x" 337 depends on GPIO_MAX732X=y && GENERIC_HARDIRQS 338 help 339 Say yes here to enable the max732x to be used as an interrupt 340 controller. It requires the driver to be built in the kernel. 341 342config GPIO_MC9S08DZ60 343 bool "MX35 3DS BOARD MC9S08DZ60 GPIO functions" 344 depends on I2C=y && MACH_MX35_3DS 345 help 346 Select this to enable the MC9S08DZ60 GPIO driver 347 348config GPIO_PCA953X 349 tristate "PCA953x, PCA955x, PCA957x, TCA64xx, and MAX7310 I/O ports" 350 depends on I2C 351 help 352 Say yes here to provide access to several register-oriented 353 SMBus I/O expanders, made mostly by NXP or TI. Compatible 354 models include: 355 356 4 bits: pca9536, pca9537 357 358 8 bits: max7310, max7315, pca6107, pca9534, pca9538, pca9554, 359 pca9556, pca9557, pca9574, tca6408 360 361 16 bits: max7312, max7313, pca9535, pca9539, pca9555, pca9575, 362 tca6416 363 364config GPIO_PCA953X_IRQ 365 bool "Interrupt controller support for PCA953x" 366 depends on GPIO_PCA953X=y 367 help 368 Say yes here to enable the pca953x to be used as an interrupt 369 controller. It requires the driver to be built in the kernel. 370 371config GPIO_PCF857X 372 tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders" 373 depends on I2C 374 select IRQ_DOMAIN 375 help 376 Say yes here to provide access to most "quasi-bidirectional" I2C 377 GPIO expanders used for additional digital outputs or inputs. 378 Most of these parts are from NXP, though TI is a second source for 379 some of them. Compatible models include: 380 381 8 bits: pcf8574, pcf8574a, pca8574, pca8574a, 382 pca9670, pca9672, pca9674, pca9674a, 383 max7328, max7329 384 385 16 bits: pcf8575, pcf8575c, pca8575, 386 pca9671, pca9673, pca9675 387 388 Your board setup code will need to declare the expanders in 389 use, and assign numbers to the GPIOs they expose. Those GPIOs 390 can then be used from drivers and other kernel code, just like 391 other GPIOs, but only accessible from task contexts. 392 393 This driver provides an in-kernel interface to those GPIOs using 394 platform-neutral GPIO calls. 395 396config GPIO_RC5T583 397 bool "RICOH RC5T583 GPIO" 398 depends on MFD_RC5T583 399 help 400 Select this option to enable GPIO driver for the Ricoh RC5T583 401 chip family. 402 This driver provides the support for driving/reading the gpio pins 403 of RC5T583 device through standard gpio library. 404 405config GPIO_SX150X 406 bool "Semtech SX150x I2C GPIO expander" 407 depends on I2C=y 408 default n 409 help 410 Say yes here to provide support for Semtech SX150-series I2C 411 GPIO expanders. Compatible models include: 412 413 8 bits: sx1508q 414 16 bits: sx1509q 415 416config GPIO_STMPE 417 bool "STMPE GPIOs" 418 depends on MFD_STMPE 419 help 420 This enables support for the GPIOs found on the STMPE I/O 421 Expanders. 422 423config GPIO_STP_XWAY 424 bool "XWAY STP GPIOs" 425 depends on SOC_XWAY 426 help 427 This enables support for the Serial To Parallel (STP) unit found on 428 XWAY SoC. The STP allows the SoC to drive a shift registers cascade, 429 that can be up to 24 bit. This peripheral is aimed at driving leds. 430 Some of the gpios/leds can be auto updated by the soc with dsl and 431 phy status. 432 433config GPIO_TC3589X 434 bool "TC3589X GPIOs" 435 depends on MFD_TC3589X 436 help 437 This enables support for the GPIOs found on the TC3589X 438 I/O Expander. 439 440config GPIO_TPS65912 441 tristate "TI TPS65912 GPIO" 442 depends on (MFD_TPS65912_I2C || MFD_TPS65912_SPI) 443 help 444 This driver supports TPS65912 gpio chip 445 446config GPIO_TWL4030 447 tristate "TWL4030, TWL5030, and TPS659x0 GPIOs" 448 depends on TWL4030_CORE 449 help 450 Say yes here to access the GPIO signals of various multi-function 451 power management chips from Texas Instruments. 452 453config GPIO_TWL6040 454 tristate "TWL6040 GPO" 455 depends on TWL6040_CORE 456 help 457 Say yes here to access the GPO signals of twl6040 458 audio chip from Texas Instruments. 459 460config GPIO_WM831X 461 tristate "WM831x GPIOs" 462 depends on MFD_WM831X 463 help 464 Say yes here to access the GPIO signals of WM831x power management 465 chips from Wolfson Microelectronics. 466 467config GPIO_WM8350 468 tristate "WM8350 GPIOs" 469 depends on MFD_WM8350 470 help 471 Say yes here to access the GPIO signals of WM8350 power management 472 chips from Wolfson Microelectronics. 473 474config GPIO_WM8994 475 tristate "WM8994 GPIOs" 476 depends on MFD_WM8994 477 help 478 Say yes here to access the GPIO signals of WM8994 audio hub 479 CODECs from Wolfson Microelectronics. 480 481config GPIO_ADP5520 482 tristate "GPIO Support for ADP5520 PMIC" 483 depends on PMIC_ADP5520 484 help 485 This option enables support for on-chip GPIO found 486 on Analog Devices ADP5520 PMICs. 487 488config GPIO_ADP5588 489 tristate "ADP5588 I2C GPIO expander" 490 depends on I2C 491 help 492 This option enables support for 18 GPIOs found 493 on Analog Devices ADP5588 GPIO Expanders. 494 495config GPIO_ADP5588_IRQ 496 bool "Interrupt controller support for ADP5588" 497 depends on GPIO_ADP5588=y 498 help 499 Say yes here to enable the adp5588 to be used as an interrupt 500 controller. It requires the driver to be built in the kernel. 501 502config GPIO_ADNP 503 tristate "Avionic Design N-bit GPIO expander" 504 depends on I2C && OF_GPIO 505 help 506 This option enables support for N GPIOs found on Avionic Design 507 I2C GPIO expanders. The register space will be extended by powers 508 of two, so the controller will need to accommodate for that. For 509 example: if a controller provides 48 pins, 6 registers will be 510 enough to represent all pins, but the driver will assume a 511 register layout for 64 pins (8 registers). 512 513comment "PCI GPIO expanders:" 514 515config GPIO_CS5535 516 tristate "AMD CS5535/CS5536 GPIO support" 517 depends on PCI && X86 && MFD_CS5535 518 help 519 The AMD CS5535 and CS5536 southbridges support 28 GPIO pins that 520 can be used for quite a number of things. The CS5535/6 is found on 521 AMD Geode and Lemote Yeeloong devices. 522 523 If unsure, say N. 524 525config GPIO_BT8XX 526 tristate "BT8XX GPIO abuser" 527 depends on PCI && VIDEO_BT848=n 528 help 529 The BT8xx frame grabber chip has 24 GPIO pins than can be abused 530 as a cheap PCI GPIO card. 531 532 This chip can be found on Miro, Hauppauge and STB TV-cards. 533 534 The card needs to be physically altered for using it as a 535 GPIO card. For more information on how to build a GPIO card 536 from a BT8xx TV card, see the documentation file at 537 Documentation/bt8xxgpio.txt 538 539 If unsure, say N. 540 541config GPIO_AMD8111 542 tristate "AMD 8111 GPIO driver" 543 depends on PCI 544 help 545 The AMD 8111 south bridge contains 32 GPIO pins which can be used. 546 547 Note, that usually system firmware/ACPI handles GPIO pins on their 548 own and users might easily break their systems with uncarefull usage 549 of this driver! 550 551 If unsure, say N 552 553config GPIO_LANGWELL 554 bool "Intel Langwell/Penwell GPIO support" 555 depends on PCI && X86 556 select IRQ_DOMAIN 557 help 558 Say Y here to support Intel Langwell/Penwell GPIO. 559 560config GPIO_PCH 561 tristate "Intel EG20T PCH/LAPIS Semiconductor IOH(ML7223/ML7831) GPIO" 562 depends on PCI && X86 563 select GENERIC_IRQ_CHIP 564 help 565 This driver is for PCH(Platform controller Hub) GPIO of Intel Topcliff 566 which is an IOH(Input/Output Hub) for x86 embedded processor. 567 This driver can access PCH GPIO device. 568 569 This driver also can be used for LAPIS Semiconductor IOH(Input/ 570 Output Hub), ML7223 and ML7831. 571 ML7223 IOH is for MP(Media Phone) use. 572 ML7831 IOH is for general purpose use. 573 ML7223/ML7831 is companion chip for Intel Atom E6xx series. 574 ML7223/ML7831 is completely compatible for Intel EG20T PCH. 575 576config GPIO_ML_IOH 577 tristate "OKI SEMICONDUCTOR ML7213 IOH GPIO support" 578 depends on PCI 579 select GENERIC_IRQ_CHIP 580 help 581 ML7213 is companion chip for Intel Atom E6xx series. 582 This driver can be used for OKI SEMICONDUCTOR ML7213 IOH(Input/Output 583 Hub) which is for IVI(In-Vehicle Infotainment) use. 584 This driver can access the IOH's GPIO device. 585 586config GPIO_SODAVILLE 587 bool "Intel Sodaville GPIO support" 588 depends on X86 && PCI && OF 589 select GPIO_GENERIC 590 select GENERIC_IRQ_CHIP 591 help 592 Say Y here to support Intel Sodaville GPIO. 593 594config GPIO_TIMBERDALE 595 bool "Support for timberdale GPIO IP" 596 depends on MFD_TIMBERDALE && HAS_IOMEM 597 ---help--- 598 Add support for the GPIO IP in the timberdale FPGA. 599 600config GPIO_RDC321X 601 tristate "RDC R-321x GPIO support" 602 depends on PCI 603 select MFD_CORE 604 select MFD_RDC321X 605 help 606 Support for the RDC R321x SoC GPIOs over southbridge 607 PCI configuration space. 608 609comment "SPI GPIO expanders:" 610 611config GPIO_MAX7301 612 tristate "Maxim MAX7301 GPIO expander" 613 depends on SPI_MASTER 614 select GPIO_MAX730X 615 help 616 GPIO driver for Maxim MAX7301 SPI-based GPIO expander. 617 618config GPIO_MCP23S08 619 tristate "Microchip MCP23xxx I/O expander" 620 depends on SPI_MASTER || I2C 621 help 622 SPI/I2C driver for Microchip MCP23S08/MCP23S17/MCP23008/MCP23017 623 I/O expanders. 624 This provides a GPIO interface supporting inputs and outputs. 625 626config GPIO_MC33880 627 tristate "Freescale MC33880 high-side/low-side switch" 628 depends on SPI_MASTER 629 help 630 SPI driver for Freescale MC33880 high-side/low-side switch. 631 This provides GPIO interface supporting inputs and outputs. 632 633config GPIO_74X164 634 tristate "74x164 serial-in/parallel-out 8-bits shift register" 635 depends on SPI_MASTER 636 help 637 Platform driver for 74x164 compatible serial-in/parallel-out 638 8-outputs shift registers. This driver can be used to provide access 639 to more gpio outputs. 640 641comment "AC97 GPIO expanders:" 642 643config GPIO_UCB1400 644 bool "Philips UCB1400 GPIO" 645 depends on UCB1400_CORE 646 help 647 This enables support for the Philips UCB1400 GPIO pins. 648 The UCB1400 is an AC97 audio codec. 649 650comment "MODULbus GPIO expanders:" 651 652config GPIO_JANZ_TTL 653 tristate "Janz VMOD-TTL Digital IO Module" 654 depends on MFD_JANZ_CMODIO 655 help 656 This enables support for the Janz VMOD-TTL Digital IO module. 657 This driver provides support for driving the pins in output 658 mode only. Input mode is not supported. 659 660config GPIO_AB8500 661 bool "ST-Ericsson AB8500 Mixed Signal Circuit gpio functions" 662 depends on AB8500_CORE && BROKEN 663 help 664 Select this to enable the AB8500 IC GPIO driver 665 666config GPIO_TPS6586X 667 bool "TPS6586X GPIO" 668 depends on MFD_TPS6586X 669 help 670 Select this option to enable GPIO driver for the TPS6586X 671 chip family. 672 673config GPIO_TPS65910 674 bool "TPS65910 GPIO" 675 depends on MFD_TPS65910 676 help 677 Select this option to enable GPIO driver for the TPS65910 678 chip family. 679 680config GPIO_MSIC 681 bool "Intel MSIC mixed signal gpio support" 682 depends on MFD_INTEL_MSIC 683 help 684 Enable support for GPIO on intel MSIC controllers found in 685 intel MID devices 686 687comment "USB GPIO expanders:" 688 689config GPIO_VIPERBOARD 690 tristate "Viperboard GPIO a & b support" 691 depends on MFD_VIPERBOARD && USB 692 help 693 Say yes here to access the GPIO signals of Nano River 694 Technologies Viperboard. There are two GPIO chips on the 695 board: gpioa and gpiob. 696 See viperboard API specification and Nano 697 River Tech's viperboard.h for detailed meaning 698 of the module parameters. 699 700endif 701