2 # GPIO infrastructure and expanders
8 Platforms select gpiolib if they use this infrastructure
9 for all their GPIOs, usually starting with ones integrated
13 depends on HAVE_GPIO_LIB
16 bool "Debug GPIO calls"
17 depends on DEBUG_KERNEL
19 Say Y here to add some extra checks and diagnostics to GPIO calls.
20 The checks help ensure that GPIOs have been properly initialized
21 before they are used and that sleeping calls aren not made from
22 nonsleeping contexts. They can make bitbanged serial protocols
23 slower. The diagnostics help catch the type of setup errors
24 that are most common when setting up new platforms or boards.
26 # put expanders in the right section, in alphabetical order
28 comment "I2C GPIO expanders:"
31 tristate "PCA9539 16-bit I/O port"
34 Say yes here to support the PCA9539 16-bit I/O port. These
35 parts are made by NXP and TI.
37 This driver can also be built as a module. If so, the module
38 will be called pca9539.
41 tristate "PCF857x, PCA857x, and PCA967x I2C GPIO expanders"
44 Say yes here to provide access to most "quasi-bidirectional" I2C
45 GPIO expanders used for additional digital outputs or inputs.
46 Most of these parts are from NXP, though TI is a second source for
47 some of them. Compatible models include:
49 8 bits: pcf8574, pcf8574a, pca8574, pca8574a,
50 pca9670, pca9672, pca9674, pca9674a
52 16 bits: pcf8575, pcf8575c, pca8575,
53 pca9671, pca9673, pca9675
55 Your board setup code will need to declare the expanders in
56 use, and assign numbers to the GPIOs they expose. Those GPIOs
57 can then be used from drivers and other kernel code, just like
58 other GPIOs, but only accessible from task contexts.
60 This driver provides an in-kernel interface to those GPIOs using
61 platform-neutral GPIO calls.
63 comment "SPI GPIO expanders:"
66 tristate "Microchip MCP23S08 I/O expander"
69 SPI driver for Microchip MCP23S08 I/O expander. This provides
70 a GPIO interface supporting inputs and outputs.