Buffered capture support

configname: CONFIG_IIO_SIMPLE_DUMMY_BUFFER

Linux Kernel Configuration
└─>Device Drivers
└─>Industrial I/O support
└─>IIO dummy driver
└─>Buffered capture support
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Add buffered data capture to the simple dummy driver.

Buffer handling elements of industrial I/O reference driver.
Uses the kfifo buffer.