1# 2# SPI driver configuration 3# 4# NOTE: the reason this doesn't show SPI slave support is mostly that 5# nobody's needed a slave side API yet. The master-role API is not 6# fully appropriate there, so it'd need some thought to do well. 7# 8menuconfig SPI 9 bool "SPI support" 10 depends on HAS_IOMEM 11 help 12 The "Serial Peripheral Interface" is a low level synchronous 13 protocol. Chips that support SPI can have data transfer rates 14 up to several tens of Mbit/sec. Chips are addressed with a 15 controller and a chipselect. Most SPI slaves don't support 16 dynamic device discovery; some are even write-only or read-only. 17 18 SPI is widely used by microcontrollers to talk with sensors, 19 eeprom and flash memory, codecs and various other controller 20 chips, analog to digital (and d-to-a) converters, and more. 21 MMC and SD cards can be accessed using SPI protocol; and for 22 DataFlash cards used in MMC sockets, SPI must always be used. 23 24 SPI is one of a family of similar protocols using a four wire 25 interface (select, clock, data in, data out) including Microwire 26 (half duplex), SSP, SSI, and PSP. This driver framework should 27 work with most such devices and controllers. 28 29if SPI 30 31config SPI_DEBUG 32 bool "Debug support for SPI drivers" 33 depends on DEBUG_KERNEL 34 help 35 Say "yes" to enable debug messaging (like dev_dbg and pr_debug), 36 sysfs, and debugfs support in SPI controller and protocol drivers. 37 38# 39# MASTER side ... talking to discrete SPI slave chips including microcontrollers 40# 41 42config SPI_MASTER 43# bool "SPI Master Support" 44 bool 45 default SPI 46 help 47 If your system has an master-capable SPI controller (which 48 provides the clock and chipselect), you can enable that 49 controller and the protocol drivers for the SPI slave chips 50 that are connected. 51 52if SPI_MASTER 53 54comment "SPI Master Controller Drivers" 55 56config SPI_ALTERA 57 tristate "Altera SPI Controller" 58 select SPI_BITBANG 59 help 60 This is the driver for the Altera SPI Controller. 61 62config SPI_ATH79 63 tristate "Atheros AR71XX/AR724X/AR913X SPI controller driver" 64 depends on ATH79 && GPIOLIB 65 select SPI_BITBANG 66 help 67 This enables support for the SPI controller present on the 68 Atheros AR71XX/AR724X/AR913X SoCs. 69 70config SPI_ATMEL 71 tristate "Atmel SPI Controller" 72 depends on HAS_DMA 73 depends on (ARCH_AT91 || AVR32 || COMPILE_TEST) 74 help 75 This selects a driver for the Atmel SPI Controller, present on 76 many AT32 (AVR32) and AT91 (ARM) chips. 77 78config SPI_BCM2835 79 tristate "BCM2835 SPI controller" 80 depends on ARCH_BCM2835 || COMPILE_TEST 81 help 82 This selects a driver for the Broadcom BCM2835 SPI master. 83 84 The BCM2835 contains two types of SPI master controller; the 85 "universal SPI master", and the regular SPI controller. This driver 86 is for the regular SPI controller. Slave mode operation is not also 87 not supported. 88 89config SPI_BFIN5XX 90 tristate "SPI controller driver for ADI Blackfin5xx" 91 depends on BLACKFIN && !BF60x 92 help 93 This is the SPI controller master driver for Blackfin 5xx processor. 94 95config SPI_ADI_V3 96 tristate "SPI controller v3 for ADI" 97 depends on BF60x 98 help 99 This is the SPI controller v3 master driver 100 found on Blackfin 60x processor. 101 102config SPI_BFIN_SPORT 103 tristate "SPI bus via Blackfin SPORT" 104 depends on BLACKFIN 105 help 106 Enable support for a SPI bus via the Blackfin SPORT peripheral. 107 108config SPI_AU1550 109 tristate "Au1550/Au1200/Au1300 SPI Controller" 110 depends on MIPS_ALCHEMY 111 select SPI_BITBANG 112 help 113 If you say yes to this option, support will be included for the 114 PSC SPI controller found on Au1550, Au1200 and Au1300 series. 115 116config SPI_BCM53XX 117 tristate "Broadcom BCM53xx SPI controller" 118 depends on ARCH_BCM_5301X 119 depends on BCMA_POSSIBLE 120 select BCMA 121 help 122 Enable support for the SPI controller on Broadcom BCM53xx ARM SoCs. 123 124config SPI_BCM63XX 125 tristate "Broadcom BCM63xx SPI controller" 126 depends on BCM63XX 127 help 128 Enable support for the SPI controller on the Broadcom BCM63xx SoCs. 129 130config SPI_BCM63XX_HSSPI 131 tristate "Broadcom BCM63XX HS SPI controller driver" 132 depends on BCM63XX || COMPILE_TEST 133 help 134 This enables support for the High Speed SPI controller present on 135 newer Broadcom BCM63XX SoCs. 136 137config SPI_BITBANG 138 tristate "Utilities for Bitbanging SPI masters" 139 help 140 With a few GPIO pins, your system can bitbang the SPI protocol. 141 Select this to get SPI support through I/O pins (GPIO, parallel 142 port, etc). Or, some systems' SPI master controller drivers use 143 this code to manage the per-word or per-transfer accesses to the 144 hardware shift registers. 145 146 This is library code, and is automatically selected by drivers that 147 need it. You only need to select this explicitly to support driver 148 modules that aren't part of this kernel tree. 149 150config SPI_BUTTERFLY 151 tristate "Parallel port adapter for AVR Butterfly (DEVELOPMENT)" 152 depends on PARPORT 153 select SPI_BITBANG 154 help 155 This uses a custom parallel port cable to connect to an AVR 156 Butterfly <http://www.atmel.com/products/avr/butterfly>, an 157 inexpensive battery powered microcontroller evaluation board. 158 This same cable can be used to flash new firmware. 159 160config SPI_CADENCE 161 tristate "Cadence SPI controller" 162 help 163 This selects the Cadence SPI controller master driver 164 used by Xilinx Zynq and ZynqMP. 165 166config SPI_CLPS711X 167 tristate "CLPS711X host SPI controller" 168 depends on ARCH_CLPS711X || COMPILE_TEST 169 help 170 This enables dedicated general purpose SPI/Microwire1-compatible 171 master mode interface (SSI1) for CLPS711X-based CPUs. 172 173config SPI_COLDFIRE_QSPI 174 tristate "Freescale Coldfire QSPI controller" 175 depends on (M520x || M523x || M5249 || M525x || M527x || M528x || M532x) 176 help 177 This enables support for the Coldfire QSPI controller in master 178 mode. 179 180config SPI_DAVINCI 181 tristate "Texas Instruments DaVinci/DA8x/OMAP-L/AM1x SoC SPI controller" 182 depends on ARCH_DAVINCI || ARCH_KEYSTONE 183 select SPI_BITBANG 184 help 185 SPI master controller for DaVinci/DA8x/OMAP-L/AM1x SPI modules. 186 187config SPI_DLN2 188 tristate "Diolan DLN-2 USB SPI adapter" 189 depends on MFD_DLN2 190 help 191 If you say yes to this option, support will be included for Diolan 192 DLN2, a USB to SPI interface. 193 194 This driver can also be built as a module. If so, the module 195 will be called spi-dln2. 196 197config SPI_EFM32 198 tristate "EFM32 SPI controller" 199 depends on OF && ARM && (ARCH_EFM32 || COMPILE_TEST) 200 select SPI_BITBANG 201 help 202 Driver for the spi controller found on Energy Micro's EFM32 SoCs. 203 204config SPI_EP93XX 205 tristate "Cirrus Logic EP93xx SPI controller" 206 depends on HAS_DMA 207 depends on ARCH_EP93XX || COMPILE_TEST 208 help 209 This enables using the Cirrus EP93xx SPI controller in master 210 mode. 211 212config SPI_FALCON 213 tristate "Falcon SPI controller support" 214 depends on SOC_FALCON 215 help 216 The external bus unit (EBU) found on the FALC-ON SoC has SPI 217 emulation that is designed for serial flash access. This driver 218 has only been tested with m25p80 type chips. The hardware has no 219 support for other types of SPI peripherals. 220 221config SPI_GPIO 222 tristate "GPIO-based bitbanging SPI Master" 223 depends on GPIOLIB 224 select SPI_BITBANG 225 help 226 This simple GPIO bitbanging SPI master uses the arch-neutral GPIO 227 interface to manage MOSI, MISO, SCK, and chipselect signals. SPI 228 slaves connected to a bus using this driver are configured as usual, 229 except that the spi_board_info.controller_data holds the GPIO number 230 for the chipselect used by this controller driver. 231 232 Note that this driver often won't achieve even 1 Mbit/sec speeds, 233 making it unusually slow for SPI. If your platform can inline 234 GPIO operations, you should be able to leverage that for better 235 speed with a custom version of this driver; see the source code. 236 237config SPI_IMG_SPFI 238 tristate "IMG SPFI controller" 239 depends on MIPS || COMPILE_TEST 240 help 241 This enables support for the SPFI master controller found on 242 IMG SoCs. 243 244config SPI_IMX 245 tristate "Freescale i.MX SPI controllers" 246 depends on ARCH_MXC || COMPILE_TEST 247 select SPI_BITBANG 248 help 249 This enables using the Freescale i.MX SPI controllers in master 250 mode. 251 252config SPI_LM70_LLP 253 tristate "Parallel port adapter for LM70 eval board (DEVELOPMENT)" 254 depends on PARPORT 255 select SPI_BITBANG 256 help 257 This driver supports the NS LM70 LLP Evaluation Board, 258 which interfaces to an LM70 temperature sensor using 259 a parallel port. 260 261config SPI_MPC52xx 262 tristate "Freescale MPC52xx SPI (non-PSC) controller support" 263 depends on PPC_MPC52xx 264 help 265 This drivers supports the MPC52xx SPI controller in master SPI 266 mode. 267 268config SPI_MPC52xx_PSC 269 tristate "Freescale MPC52xx PSC SPI controller" 270 depends on PPC_MPC52xx 271 help 272 This enables using the Freescale MPC52xx Programmable Serial 273 Controller in master SPI mode. 274 275config SPI_MPC512x_PSC 276 tristate "Freescale MPC512x PSC SPI controller" 277 depends on PPC_MPC512x 278 help 279 This enables using the Freescale MPC5121 Programmable Serial 280 Controller in SPI master mode. 281 282config SPI_FSL_LIB 283 tristate 284 depends on OF 285 286config SPI_FSL_CPM 287 tristate 288 depends on FSL_SOC 289 290config SPI_FSL_SPI 291 tristate "Freescale SPI controller and Aeroflex Gaisler GRLIB SPI controller" 292 depends on OF 293 select SPI_FSL_LIB 294 select SPI_FSL_CPM if FSL_SOC 295 help 296 This enables using the Freescale SPI controllers in master mode. 297 MPC83xx platform uses the controller in cpu mode or CPM/QE mode. 298 MPC8569 uses the controller in QE mode, MPC8610 in cpu mode. 299 This also enables using the Aeroflex Gaisler GRLIB SPI controller in 300 master mode. 301 302config SPI_FSL_DSPI 303 tristate "Freescale DSPI controller" 304 select REGMAP_MMIO 305 depends on SOC_VF610 || COMPILE_TEST 306 help 307 This enables support for the Freescale DSPI controller in master 308 mode. VF610 platform uses the controller. 309 310config SPI_FSL_ESPI 311 tristate "Freescale eSPI controller" 312 depends on FSL_SOC 313 select SPI_FSL_LIB 314 help 315 This enables using the Freescale eSPI controllers in master mode. 316 From MPC8536, 85xx platform uses the controller, and all P10xx, 317 P20xx, P30xx,P40xx, P50xx uses this controller. 318 319config SPI_MESON_SPIFC 320 tristate "Amlogic Meson SPIFC controller" 321 depends on ARCH_MESON || COMPILE_TEST 322 select REGMAP_MMIO 323 help 324 This enables master mode support for the SPIFC (SPI flash 325 controller) available in Amlogic Meson SoCs. 326 327config SPI_OC_TINY 328 tristate "OpenCores tiny SPI" 329 depends on GPIOLIB 330 select SPI_BITBANG 331 help 332 This is the driver for OpenCores tiny SPI master controller. 333 334config SPI_OCTEON 335 tristate "Cavium OCTEON SPI controller" 336 depends on CAVIUM_OCTEON_SOC 337 help 338 SPI host driver for the hardware found on some Cavium OCTEON 339 SOCs. 340 341config SPI_OMAP_UWIRE 342 tristate "OMAP1 MicroWire" 343 depends on ARCH_OMAP1 344 select SPI_BITBANG 345 help 346 This hooks up to the MicroWire controller on OMAP1 chips. 347 348config SPI_OMAP24XX 349 tristate "McSPI driver for OMAP" 350 depends on HAS_DMA 351 depends on ARM || ARM64 || AVR32 || HEXAGON || MIPS || SUPERH 352 depends on ARCH_OMAP2PLUS || COMPILE_TEST 353 help 354 SPI master controller for OMAP24XX and later Multichannel SPI 355 (McSPI) modules. 356 357config SPI_TI_QSPI 358 tristate "DRA7xxx QSPI controller support" 359 depends on ARCH_OMAP2PLUS || COMPILE_TEST 360 help 361 QSPI master controller for DRA7xxx used for flash devices. 362 This device supports single, dual and quad read support, while 363 it only supports single write mode. 364 365config SPI_OMAP_100K 366 tristate "OMAP SPI 100K" 367 depends on ARCH_OMAP850 || ARCH_OMAP730 || COMPILE_TEST 368 help 369 OMAP SPI 100K master controller for omap7xx boards. 370 371config SPI_ORION 372 tristate "Orion SPI master" 373 depends on PLAT_ORION || COMPILE_TEST 374 help 375 This enables using the SPI master controller on the Orion chips. 376 377config SPI_PL022 378 tristate "ARM AMBA PL022 SSP controller" 379 depends on ARM_AMBA 380 default y if MACH_U300 381 default y if ARCH_REALVIEW 382 default y if INTEGRATOR_IMPD1 383 default y if ARCH_VERSATILE 384 help 385 This selects the ARM(R) AMBA(R) PrimeCell PL022 SSP 386 controller. If you have an embedded system with an AMBA(R) 387 bus and a PL022 controller, say Y or M here. 388 389config SPI_PPC4xx 390 tristate "PPC4xx SPI Controller" 391 depends on PPC32 && 4xx 392 select SPI_BITBANG 393 help 394 This selects a driver for the PPC4xx SPI Controller. 395 396config SPI_PXA2XX_PXADMA 397 bool "PXA2xx SSP legacy PXA DMA API support" 398 depends on SPI_PXA2XX && ARCH_PXA 399 help 400 Enable PXA private legacy DMA API support. Note that this is 401 deprecated in favor of generic DMA engine API. 402 403config SPI_PXA2XX_DMA 404 def_bool y 405 depends on SPI_PXA2XX && !SPI_PXA2XX_PXADMA 406 407config SPI_PXA2XX 408 tristate "PXA2xx SSP SPI master" 409 depends on (ARCH_PXA || PCI || ACPI) 410 select PXA_SSP if ARCH_PXA 411 help 412 This enables using a PXA2xx or Sodaville SSP port as a SPI master 413 controller. The driver can be configured to use any SSP port and 414 additional documentation can be found a Documentation/spi/pxa2xx. 415 416config SPI_PXA2XX_PCI 417 def_tristate SPI_PXA2XX && PCI && COMMON_CLK 418 419config SPI_ROCKCHIP 420 tristate "Rockchip SPI controller driver" 421 depends on ARM || ARM64 || AVR32 || HEXAGON || MIPS || SUPERH 422 help 423 This selects a driver for Rockchip SPI controller. 424 425 If you say yes to this option, support will be included for 426 RK3066, RK3188 and RK3288 families of SPI controller. 427 Rockchip SPI controller support DMA transport and PIO mode. 428 The main usecase of this controller is to use spi flash as boot 429 device. 430 431config SPI_RSPI 432 tristate "Renesas RSPI/QSPI controller" 433 depends on SUPERH || ARCH_SHMOBILE || COMPILE_TEST 434 help 435 SPI driver for Renesas RSPI and QSPI blocks. 436 437config SPI_QUP 438 tristate "Qualcomm SPI controller with QUP interface" 439 depends on ARCH_QCOM || (ARM && COMPILE_TEST) 440 help 441 Qualcomm Universal Peripheral (QUP) core is an AHB slave that 442 provides a common data path (an output FIFO and an input FIFO) 443 for serial peripheral interface (SPI) mini-core. SPI in master 444 mode supports up to 50MHz, up to four chip selects, programmable 445 data path from 4 bits to 32 bits and numerous protocol variants. 446 447 This driver can also be built as a module. If so, the module 448 will be called spi_qup. 449 450config SPI_S3C24XX 451 tristate "Samsung S3C24XX series SPI" 452 depends on ARCH_S3C24XX 453 select SPI_BITBANG 454 help 455 SPI driver for Samsung S3C24XX series ARM SoCs 456 457config SPI_S3C24XX_FIQ 458 bool "S3C24XX driver with FIQ pseudo-DMA" 459 depends on SPI_S3C24XX 460 select FIQ 461 help 462 Enable FIQ support for the S3C24XX SPI driver to provide pseudo 463 DMA by using the fast-interrupt request framework, This allows 464 the driver to get DMA-like performance when there are either 465 no free DMA channels, or when doing transfers that required both 466 TX and RX data paths. 467 468config SPI_S3C64XX 469 tristate "Samsung S3C64XX series type SPI" 470 depends on (PLAT_SAMSUNG || ARCH_EXYNOS) 471 help 472 SPI driver for Samsung S3C64XX and newer SoCs. 473 474config SPI_SC18IS602 475 tristate "NXP SC18IS602/602B/603 I2C to SPI bridge" 476 depends on I2C 477 help 478 SPI driver for NXP SC18IS602/602B/603 I2C to SPI bridge. 479 480config SPI_SH_MSIOF 481 tristate "SuperH MSIOF SPI controller" 482 depends on HAVE_CLK && HAS_DMA 483 depends on SUPERH || ARCH_SHMOBILE || COMPILE_TEST 484 help 485 SPI driver for SuperH and SH Mobile MSIOF blocks. 486 487config SPI_SH 488 tristate "SuperH SPI controller" 489 depends on SUPERH || COMPILE_TEST 490 help 491 SPI driver for SuperH SPI blocks. 492 493config SPI_SH_SCI 494 tristate "SuperH SCI SPI controller" 495 depends on SUPERH 496 select SPI_BITBANG 497 help 498 SPI driver for SuperH SCI blocks. 499 500config SPI_SH_HSPI 501 tristate "SuperH HSPI controller" 502 depends on ARCH_SHMOBILE || COMPILE_TEST 503 help 504 SPI driver for SuperH HSPI blocks. 505 506config SPI_SIRF 507 tristate "CSR SiRFprimaII SPI controller" 508 depends on SIRF_DMA 509 select SPI_BITBANG 510 help 511 SPI driver for CSR SiRFprimaII SoCs 512 513config SPI_ST_SSC4 514 tristate "STMicroelectronics SPI SSC-based driver" 515 depends on ARCH_STI 516 help 517 STMicroelectronics SoCs support for SPI. If you say yes to 518 this option, support will be included for the SSC driven SPI. 519 520config SPI_SUN4I 521 tristate "Allwinner A10 SoCs SPI controller" 522 depends on ARCH_SUNXI || COMPILE_TEST 523 help 524 SPI driver for Allwinner sun4i, sun5i and sun7i SoCs 525 526config SPI_SUN6I 527 tristate "Allwinner A31 SPI controller" 528 depends on ARCH_SUNXI || COMPILE_TEST 529 depends on RESET_CONTROLLER 530 help 531 This enables using the SPI controller on the Allwinner A31 SoCs. 532 533config SPI_MXS 534 tristate "Freescale MXS SPI controller" 535 depends on ARCH_MXS 536 select STMP_DEVICE 537 help 538 SPI driver for Freescale MXS devices. 539 540config SPI_TEGRA114 541 tristate "NVIDIA Tegra114 SPI Controller" 542 depends on (ARCH_TEGRA && TEGRA20_APB_DMA) || COMPILE_TEST 543 depends on RESET_CONTROLLER && HAS_DMA 544 help 545 SPI driver for NVIDIA Tegra114 SPI Controller interface. This controller 546 is different than the older SoCs SPI controller and also register interface 547 get changed with this controller. 548 549config SPI_TEGRA20_SFLASH 550 tristate "Nvidia Tegra20 Serial flash Controller" 551 depends on ARCH_TEGRA || COMPILE_TEST 552 depends on RESET_CONTROLLER 553 help 554 SPI driver for Nvidia Tegra20 Serial flash Controller interface. 555 The main usecase of this controller is to use spi flash as boot 556 device. 557 558config SPI_TEGRA20_SLINK 559 tristate "Nvidia Tegra20/Tegra30 SLINK Controller" 560 depends on (ARCH_TEGRA && TEGRA20_APB_DMA) || COMPILE_TEST 561 depends on RESET_CONTROLLER && HAS_DMA 562 help 563 SPI driver for Nvidia Tegra20/Tegra30 SLINK Controller interface. 564 565config SPI_TOPCLIFF_PCH 566 tristate "Intel EG20T PCH/LAPIS Semicon IOH(ML7213/ML7223/ML7831) SPI" 567 depends on PCI && (X86_32 || COMPILE_TEST) 568 help 569 SPI driver for the Topcliff PCH (Platform Controller Hub) SPI bus 570 used in some x86 embedded processors. 571 572 This driver also supports the ML7213/ML7223/ML7831, a companion chip 573 for the Atom E6xx series and compatible with the Intel EG20T PCH. 574 575config SPI_TXX9 576 tristate "Toshiba TXx9 SPI controller" 577 depends on GPIOLIB && (CPU_TX49XX || COMPILE_TEST) 578 help 579 SPI driver for Toshiba TXx9 MIPS SoCs 580 581config SPI_XCOMM 582 tristate "Analog Devices AD-FMCOMMS1-EBZ SPI-I2C-bridge driver" 583 depends on I2C 584 help 585 Support for the SPI-I2C bridge found on the Analog Devices 586 AD-FMCOMMS1-EBZ board. 587 588config SPI_XILINX 589 tristate "Xilinx SPI controller common module" 590 depends on HAS_IOMEM 591 select SPI_BITBANG 592 help 593 This exposes the SPI controller IP from the Xilinx EDK. 594 595 See the "OPB Serial Peripheral Interface (SPI) (v1.00e)" 596 Product Specification document (DS464) for hardware details. 597 598 Or for the DS570, see "XPS Serial Peripheral Interface (SPI) (v2.00b)" 599 600config SPI_XTENSA_XTFPGA 601 tristate "Xtensa SPI controller for xtfpga" 602 depends on (XTENSA && XTENSA_PLATFORM_XTFPGA) || COMPILE_TEST 603 select SPI_BITBANG 604 help 605 SPI driver for xtfpga SPI master controller. 606 607 This simple SPI master controller is built into xtfpga bitstreams 608 and is used to control daughterboard audio codec. It always transfers 609 16 bit words in SPI mode 0, automatically asserting CS on transfer 610 start and deasserting on end. 611 612config SPI_NUC900 613 tristate "Nuvoton NUC900 series SPI" 614 depends on ARCH_W90X900 615 select SPI_BITBANG 616 help 617 SPI driver for Nuvoton NUC900 series ARM SoCs 618 619# 620# Add new SPI master controllers in alphabetical order above this line 621# 622 623config SPI_DESIGNWARE 624 tristate "DesignWare SPI controller core support" 625 help 626 general driver for SPI controller core from DesignWare 627 628config SPI_DW_PCI 629 tristate "PCI interface driver for DW SPI core" 630 depends on SPI_DESIGNWARE && PCI 631 632config SPI_DW_MID_DMA 633 bool "DMA support for DW SPI controller on Intel MID platform" 634 depends on SPI_DW_PCI && DW_DMAC_PCI 635 636config SPI_DW_MMIO 637 tristate "Memory-mapped io interface driver for DW SPI core" 638 depends on SPI_DESIGNWARE 639 640# 641# There are lots of SPI device types, with sensors and memory 642# being probably the most widely used ones. 643# 644comment "SPI Protocol Masters" 645 646config SPI_SPIDEV 647 tristate "User mode SPI device driver support" 648 help 649 This supports user mode SPI protocol drivers. 650 651 Note that this application programming interface is EXPERIMENTAL 652 and hence SUBJECT TO CHANGE WITHOUT NOTICE while it stabilizes. 653 654config SPI_TLE62X0 655 tristate "Infineon TLE62X0 (for power switching)" 656 depends on SYSFS 657 help 658 SPI driver for Infineon TLE62X0 series line driver chips, 659 such as the TLE6220, TLE6230 and TLE6240. This provides a 660 sysfs interface, with each line presented as a kind of GPIO 661 exposing both switch control and diagnostic feedback. 662 663# 664# Add new SPI protocol masters in alphabetical order above this line 665# 666 667endif # SPI_MASTER 668 669# (slave support would go here) 670 671endif # SPI 672