ADAU7118

ADAU7118 8 Channel, PDM to I2S or TDM Conversion IC Linux Driver.

Supported Devices

Evaluation Boards

Description

The ADAU7118 converts four stereo pulse density modulation (PDM) bitstreams into one pulse code modulation (PCM) output stream. The source for the PDM data can be eight microphones or other PDM sources. The PCM audio data is output on a serial audio interface port in either inter-IC serial (I2S) or time domain multiplexed (TDM) format. The ADAU7118 has an I2C interface which can be used to fully configure the device. It can set the device to operate either in stereo or TDM mode, disable/enable inputs, etc… Furthermore, the device can also operate in HW only mode where the I2C interface is disabled. In this mode, only TDM mode is supported.

Source Code

Status

Source

Mainlined?

sound/soc/codecs/adau7118.c

yes

sound/soc/codecs/adau7118.h

yes

sound/soc/codecs/adau7118-i2c.c

yes

sound/soc/codecs/adau7118-hw.c

yes

Files

Function

File

core driver

sound/soc/codecs/adau7118.c

core include

sound/soc/codecs/adau7118.h

driver

sound/soc/codecs/adau7118-i2c.c

driver

sound/soc/codecs/adau7118-hw.c

devicetree

Documentation/devicetree/bindings/sound/adi,adau7118.yaml

Adding Linux driver support

Kernel configuration

Device Drivers  --->
<*> Sound card support  --->
<*>   Advanced Linux Sound Architecture  --->
<*>     ALSA for SoC audio support  --->
<*>       CODEC drivers  --->
<*>          Analog Devices ADAU7118 8 Channel PDM-to-I2S/TDM Converter - HW Mode
<*>          Analog Devices ADAU7118 8 Channel PDM-to-I2S/TDM Converter - I2C

Devicetree configuration

The ADAU7118 driver is fully devicetree compatible.

Required properties:

  • compatible: Must be adi,adau7118

  • #sound-dai-cells: Must be 0

  • iovdd-supply: Regulator phandle for the digital I/O supply.

  • dvdd-supply: Regulator phandle for the internal core digital supply.

Optional properties:

  • reg: I2C address when the device is used with I2C support.

  • adi,decimation-ratio: Set’s the decimation ratio of PDM to PCM audio data.

  • adi,pdm-clk-map: The ADAU7118 has two PDM clocks for the four Inputs. Each input must be assigned to one of these two clocks. This property set’s the mapping between the clocks and the inputs.

Example device initialization

The ADAU7118 supports I2C control and standalone hardware mode. Both examples require lowercase iovdd-supply and dvdd-supply properties and #sound-dai-cells = <0>. The board must define the actual supply and supply2 regulators; these labels do not imply fixed voltages.

I2C mode

The board must define i2c0. Match the address and interface configuration to the connected device.

&i2c0 {
    #address-cells = <1>;
    #size-cells = <0>;
    status = "okay";

    adau7118_codec: audio-codec@14 {
        compatible = "adi,adau7118";
        reg = <0x14>;
        #sound-dai-cells = <0>;
        iovdd-supply = <&supply>;
        dvdd-supply = <&supply2>;
        adi,pdm-clk-map = <1 1 0 0>;
        adi,decimation-ratio = <16>;
    };
};
HW mode

Standalone hardware mode uses an unaddressed platform node, not an I2C address or a reg property. Configure the device’s hardware straps for the actual board interface.

/ {
    adau7118_codec_hw: adau7118-codec-hw {
        compatible = "adi,adau7118";
        #sound-dai-cells = <0>;
        iovdd-supply = <&supply>;
        dvdd-supply = <&supply2>;
    };
};

Driver testing

Routing and DAPM

ASoC DAPM widgets (HW Mode)

Name

Description

PDM_DAT0

PDM0 signal input

PDM_DAT1

PDM1 signal input

PDM_DAT2

PDM2 signal input

PDM_DAT3

PDM3 signal input

AIF1TX

Audio Interface Output

ASoC DAPM widgets (I2C)

Name

Description

PDM_DAT0

PDM0 signal input

PDM_DAT1

PDM1 signal input

PDM_DAT2

PDM2 signal input

PDM_DAT3

PDM3 signal input

PDM0

PDM0 switch control

PDM1

PDM1 switch control

PDM2

PDM2 switch control

PDM3

PDM3 switch control

PDM_CLK0

Clock0 supply widget

PDM_CLK1

Clock1 supply widget

AIF1TX1

Audio Interface Output - Channel 1

AIF1TX2

Audio Interface Output - Channel 2

AIF1TX3

Audio Interface Output - Channel 3

AIF1TX4

Audio Interface Output - Channel 4

AIF1TX5

Audio Interface Output - Channel 5

AIF1TX6

Audio Interface Output - Channel 6

AIF1TX7

Audio Interface Output - Channel 7

AIF1TX8

Audio Interface Output - Channel 8

ALSA controls

Name

Description

Capture Switch

PDM0 input enable

Capture Switch

PDM1 input enable

Capture Switch

PDM2 input enable

Capture Switch

PDM3 input enable

DAI formats and clocks

DAI Configuration

The driver registers one DAI called ``adau7118-hifi-capture``.

Supported DAI formats

Name

Supported by driver

Description

SND_SOC_DAIFMT_I2S

yes*

I2S mode

SND_SOC_DAIFMT_RIGHT_J

yes*

Right Justified mode

SND_SOC_DAIFMT_LEFT_J

yes*

Left Justified mode

SND_SOC_DAIFMT_DSP_A

no

data MSB after FRM LRC

SND_SOC_DAIFMT_DSP_B

no

data MSB during FRM LRC

SND_SOC_DAIFMT_AC97

no

AC97 mode

SND_SOC_DAIFMT_PDM

no

Pulse density modulation

SND_SOC_DAIFMT_NB_NF

yes*

Normal bit- and frameclock

SND_SOC_DAIFMT_NB_IF

yes*

Normal bitclock, inverted frameclock

SND_SOC_DAIFMT_IB_NF

yes*

Inverted frameclock, normal bitclock

SND_SOC_DAIFMT_IB_IF

yes*

Inverted bit- and frameclock

SND_SOC_DAIFMT_CBM_CFM

no

Codec bit- and frameclock master

SND_SOC_DAIFMT_CBS_CFM

no

Codec bitclock slave, frameclock master

SND_SOC_DAIFMT_CBM_CFS

no

Codec bitclock master, frameclock slave

SND_SOC_DAIFMT_CBS_CFS

yes

Codec bit- and frameclock slave

* The supported DAI format are limited for HW only mode (only I2S and Normal bit- and frameclock is supported). In this mode, the I2C SCL and SDA pins are used to select different functionality. Check table 11 of the datasheet for more details.

More Information

Need Help?