• Machine driver-handles any machine specific controls and audio events, such as
turning on an external amp at the beginning of playback.
• Platform driver-contains the audio DMA engine and audio interface drivers (for
example, I
2
S, AC97, PCM) for that platform.
• CODEC driver-platform independent and contains audio controls, audio interface
capabilities, the CODEC DAPM definition, and CODEC I/O functions.
More detailed information about ASoC can be found in the Linux kernel documentation
in the linux source tree at linux/Documentation/sound/alsa/soc and at
project.org/main/index.php/ASoC
25.2 SoC Sound Card
Currently, the stereo CODEC (wm8962), 7.1 CODEC (cs42888), and AM/FM CODEC
drivers are implemented by using SoC architecture.
These sound card drivers are built in independently. The stereo sound card supports
stereo playback and capture. The 7.1 sound card supports up to eight channels of audio
playback, while enabling ASRC, 7.1 sound card only supports 2 or 6 channels audio
playback. The AM/FM sound card supports radio PCM capture.
NOTE
The 7.1 CODEC is only supported on the i.MX 6Quad Sabre-
AI platform.
The AM/FM CODEC is only supported on the i.MX 6Quad
Sabre-AI platform.
25.2.1 Stereo CODEC Features
The stereo CODEC supports the following features:
• Sample rates for playback and capture are 8KHz, 32 KHz, 44.1 KHz, 48 KHz, and 96
KHz
• Channels:
• Playback: supports two channels.
• Capture: supports two channels.
• Audio formats:
• Playback:
• SNDRV_PCM_FMTBIT_S16_LE
SoC Sound Card
i.MX 6Solo/6DualLite Linux Reference Manual, Rev. L3.0.35_4.1.0, 09/2013
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Freescale Semiconductor, Inc.
