PCA953x, PCA955x, and MAX7310 I/O ports

modulename: pca953x.ko

and/or

gpio-pca953x.ko

configname: CONFIG_GPIO_PCA953X

Linux Kernel Configuration
└─>Device Drivers
└─>GPIO Support
└─>I2C support
└─>PCA953x, PCA955x, and MAX7310 I/O ports
In linux kernel since version 2.6.25 (release Date: 2008-04-16)  
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.

source code: