Design of WM8976 Audio Driver Based on ALSA

The WM8976 driver of an audio processor system was designed on basis of Linux operating system.It was composed of embedded processor i.MX27 and codec WM896.The audio system used by the codec driver can be applied in fields of video monitoring system,school teaching and tourist guide.The codec was configured by I2C bus and the audio data was serially transferred through I2S bus,realizing the codec driver.At the same time,ALSA structure was used to record and playback.In the design,the use of audio DMA double buffer can effectively enhance the ability of processing audio data.Tests verify that the system can achieve the recording and playback of various frequencies and the tone is very good.