I2S

This document provides a guide for configuring the Audio I2S interfaces on the Genio 520/720-EVK.

Overview

Genio 520/720-EVK exposes four I2S interfaces, supporting multiple data formats suitable for interfacing with various external codecs, DSPs, or Bluetooth modules.

In terms of clock capabilities, I2SOUT0, I2SOUT1, and I2SIN0 support Master mode only, whereas I2SIN1 supports both Master and Slave modes.

I2S Interfaces

The table below details the I2S interface mapping to the AFE route diagram and Backend DAI names:

I2S Interface Mapping

Interface Name	Block on AFE Route Diagram	Front End DAI Name	Back End DAI Name
I2SOUT0	eTDM out0	DL1	I2SOUT0_BE
I2SOUT1	eTDM out1	DL3	I2SOUT1_BE
I2SIN0	eTDM in0	UL1	I2SIN0_BE
I2SIN1	eTDM in1	UL3	I2SIN1_BE

Genio 520/720-EVK I2S Interfaces

Device Tree Configuration

The I2S configuration is primarily handled within the Sound Card node in the Device Tree Source (DTS). Specifically, settings are applied within the dai-link subnodes under the &sound node.

Properties Used

To configure the I2S parameters, modify the specific dai-link node corresponding to the target I2S interface (Back End DAI).

• mediatek,clk-provider

  Defines the clock master/slave relationship between the SoC and the Codec.

  Clock Provider Configuration

  Value	Clock Provider (Master)	G520/G720 Role
  cpu	G520/G720 SoC	Master (default)
  codec	External Codec	Slave

  Usage:

  mediatek,clk-provider = "codec";
  

  Note

  Only I2SIN1 supports Slave mode. All other I2S interfaces support Master mode only.

• dai-format

  Specifies the audio data protocol format.

  Supported DAI Formats

  Value	Description
  i2s	Standard I2S format
  left_j	Left Justified
  right_j	Right Justified
  dsp_a	DSP Mode A (PCM A)
  dsp_b	DSP Mode B (PCM B)

  Usage:

  dai-format = "dsp_a";
  

Configuration Example

The following example demonstrates how to configure I2SIN1 as a Slave device using the Left Justified format.

DTS Snippet

&sound {
    /* ... other sound card properties ... */

    /* Backend DAI Link for I2SIN1 */
    dai-link-3 {
        link-name = "I2SIN1_BE";

        mediatek,clk-provider = "codec";
        dai-format = "left_j";
    };
};

Note

• Ensure that the link-name matches the backend definitions expected by the ASoC machine driver for the G720 platform.

• The numbering of dai-link-X may differ depending on the specific implementation. Please adjust according to your DTS configuration.

Limitations

Conflict between I2SOUT0 and eDP

I2SOUT0 and eDP are mutually exclusive due to the hardware resource conflict on GPIO108, GPIO109, and GPIO110.

Although these pins are assigned to I2SOUT0 by default, enabling eDP takes precedence. Consequently, the system will automatically disable I2SOUT0 when eDP is active.

Conflict between I2SIN0 and IT6625

I2SIN0 and IT6625 cannot be used simultaneously as they share the same pin GPIO103. This pin is required by I2SIN0 for the MCLK signal and by IT6625 for interrupt.

By default, the system enables I2SIN0. However, enabling IT6625 will override this setting and automatically disable I2SIN0 to accommodate the interrupt requirement.