What: /sys/bus/platform/devices/[..]/fsi-master-gpio/external_mode Date: Feb 2018 KernelVersion: 4.17 Contact: jk@ozlabs.org Description: Controls access arbitration for GPIO-based FSI master. A value of 0 (the default) sets normal mode, where the driver performs FSI bus transactions, 1 sets external mode, where the FSI bus is driven externally (for example, by a debug device).