Intel IXP4xx HSS (synchronous serial port) support

modulename: ixp4xx_hss.ko

configname: CONFIG_IXP4XX_HSS

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Wan interfaces support
└─>Device Tree and Open Firmware support
└─>Intel IXP4xx HSS (synchronous serial port) support
In linux kernel since version 2.6.29 (release Date: 2009-03-23)  
Say Y here if you want to use built-in HSS ports
on IXP4xx processor.

source code:
drivers/net/wan/ixp4xx_hss.c