GPIO controlled MDIO bus multiplexers

modulename: mdio-mux-gpio.ko

configname: CONFIG_MDIO_BUS_MUX_GPIO

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>PHY Device support and infrastructure
└─>GPIO controlled MDIO bus multiplexers
In linux kernel since version 3.1 (release Date: 2011-10-24)  
This module provides a driver for MDIO bus multiplexers that
are controlled via GPIO lines. The multiplexer connects one of
several child MDIO busses to a parent bus. Child bus
selection is under the control of GPIO lines.

source code: