| # |
| # GPIO infrastructure and expanders |
| # |
| |
| config ARCH_WANT_OPTIONAL_GPIOLIB |
| bool |
| help |
| Select this config option from the architecture Kconfig, if |
| it is possible to use gpiolib on the architecture, but let the |
| user decide whether to actually build it or not. |
| Select this instead of ARCH_REQUIRE_GPIOLIB, if your architecture does |
| not depend on GPIOs being available, but rather let the user |
| decide whether he needs it or not. |
| |
| config ARCH_REQUIRE_GPIOLIB |
| bool |
| select GPIOLIB |
| help |
| Platforms select gpiolib if they use this infrastructure |
| for all their GPIOs, usually starting with ones integrated |
| into SOC processors. |
| Selecting this from the architecture code will cause the gpiolib |
| code to always get built in. |
| |
| |
| |
| menuconfig GPIOLIB |
| bool "GPIO Support" |
| depends on ARCH_WANT_OPTIONAL_GPIOLIB || ARCH_REQUIRE_GPIOLIB |
| select GENERIC_GPIO |
| help |
| This enables GPIO support through the generic GPIO library. |
| You only need to enable this, if you also want to enable |
| one or more of the GPIO expansion card drivers below. |
| |
| If unsure, say N. |
| |
| if GPIOLIB |
| |
| config DEBUG_GPIO |
| bool "Debug GPIO calls" |
| depends on DEBUG_KERNEL |
| help |
| Say Y here to add some extra checks and diagnostics to GPIO calls. |
| The checks help ensure that GPIOs have been properly initialized |
| before they are used and that sleeping calls aren not made from |
| nonsleeping contexts. They can make bitbanged serial protocols |
| slower. The diagnostics help catch the type of setup errors |
| that are most common when setting up new platforms or boards. |
| |
| config GPIO_SYSFS |
| bool "/sys/class/gpio/... (sysfs interface)" |
| depends on SYSFS && EXPERIMENTAL |
| help |
| Say Y here to add a sysfs interface for GPIOs. |
| |
| This is mostly useful to work around omissions in a system's |
| kernel support. Those are common in custom and semicustom |
| hardware assembled using standard kernels with a minimum of |
| custom patches. In those cases, userspace code may import |
| a given GPIO from the kernel, if no kernel driver requested it. |
| |
| Kernel drivers may also request that a particular GPIO be |
| exported to userspace; this can be useful when debugging. |
| |
| # put expanders in the right section, in alphabetical order |
| |
| comment "I2C GPIO expanders:" |
| |
| config GPIO_PCA953X |
| tristate "PCA953x, PCA955x, and MAX7310 I/O ports" |
| depends on I2C |
| help |
| Say yes here to provide access to several register-oriented |
| SMBus I/O expanders, made mostly by NXP or TI. Compatible |
| models include: |
| |
| 4 bits: pca9536, pca9537 |
| |
| 8 bits: max7310, pca9534, pca9538, pca9554, pca9557 |
| |
| 16 bits: pca9535, pca9539, pca9555 |
| |
| This driver can also be built as a module. If so, the module |
| will be called pca953x. |
| |
| config GPIO_PCF857X |
| tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders" |
| depends on I2C |
| help |
| Say yes here to provide access to most "quasi-bidirectional" I2C |
| GPIO expanders used for additional digital outputs or inputs. |
| Most of these parts are from NXP, though TI is a second source for |
| some of them. Compatible models include: |
| |
| 8 bits: pcf8574, pcf8574a, pca8574, pca8574a, |
| pca9670, pca9672, pca9674, pca9674a, |
| max7328, max7329 |
| |
| 16 bits: pcf8575, pcf8575c, pca8575, |
| pca9671, pca9673, pca9675 |
| |
| Your board setup code will need to declare the expanders in |
| use, and assign numbers to the GPIOs they expose. Those GPIOs |
| can then be used from drivers and other kernel code, just like |
| other GPIOs, but only accessible from task contexts. |
| |
| This driver provides an in-kernel interface to those GPIOs using |
| platform-neutral GPIO calls. |
| |
| comment "PCI GPIO expanders:" |
| |
| config GPIO_BT8XX |
| tristate "BT8XX GPIO abuser" |
| depends on PCI && VIDEO_BT848=n |
| help |
| The BT8xx frame grabber chip has 24 GPIO pins than can be abused |
| as a cheap PCI GPIO card. |
| |
| This chip can be found on Miro, Hauppauge and STB TV-cards. |
| |
| The card needs to be physically altered for using it as a |
| GPIO card. For more information on how to build a GPIO card |
| from a BT8xx TV card, see the documentation file at |
| Documentation/bt8xxgpio.txt |
| |
| If unsure, say N. |
| |
| comment "SPI GPIO expanders:" |
| |
| config GPIO_MAX7301 |
| tristate "Maxim MAX7301 GPIO expander" |
| depends on SPI_MASTER |
| help |
| gpio driver for Maxim MAX7301 SPI GPIO expander. |
| |
| config GPIO_MCP23S08 |
| tristate "Microchip MCP23S08 I/O expander" |
| depends on SPI_MASTER |
| help |
| SPI driver for Microchip MCP23S08 I/O expander. This provides |
| a GPIO interface supporting inputs and outputs. |
| |
| endif |