120 lines
3.6 KiB
Plaintext
120 lines
3.6 KiB
Plaintext
#
|
|
# GPIO infrastructure and expanders
|
|
#
|
|
|
|
config HAVE_GPIO_LIB
|
|
bool
|
|
help
|
|
Platforms select gpiolib if they use this infrastructure
|
|
for all their GPIOs, usually starting with ones integrated
|
|
into SOC processors.
|
|
|
|
menu "GPIO Support"
|
|
depends on HAVE_GPIO_LIB
|
|
|
|
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.
|
|
|
|
endmenu
|