PCM PIO extension for I2S driver

configname: CONFIG_SND_DESIGNWARE_PCM

Linux Kernel Configuration
└─>Device Drivers
└─>Sound card support
└─>Advanced Linux Sound Architecture
└─>ALSA for SoC audio support
└─>PCM PIO extension for I2S driver
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Say Y or N if you want to add a custom ALSA extension that registers
a PCM and uses PIO to transfer data.

This functionality is specially suited for I2S devices that don't have
DMA support.