gpiolib: pcf857x i2c gpio expander support

[deliverable/linux.git] / drivers / gpio / Kconfig

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 560687c4667e9d0abba8db1d21e1c054ca5b5e33..36d5d6aefc0ee73c60e5969616c97890c199485e 100644 (file)
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -27,6 +27,29 @@ config DEBUG_GPIO
 
 comment "I2C GPIO expanders:"
 
+config GPIO_PCF857X
+       tristate "PCF857x, PCA857x, and PCA967x 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
+
+         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 "SPI GPIO expanders:"
 
 endmenu