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This version (13 Dec 2019 14:27) was approved by nsa.The Previously approved version (23 Sep 2019 13:36) is available.Diff

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.

Status

Files

Devicetree bindings

The ADAU7118 driver is fully devicetree compatible.

Required properties:

  • compatible: Must be “adi,adau7118”
  • #sound-dai-cells: Must be 0

Optional properties:

  • reg: I2C address when the device is used with I2C support.
  • IOVDD-supply: Phandle and specifier for the power supply providing the IOVDD supply as covered in Documentation/devicetree/bindings/regulator/regulator.txt. If this property is not present it is assumed that the supply pin is hardwired to always on.
  • DVDD-supply: Phandle and specifier for the power supply providing the DVDD supply as covered in Documentation/devicetree/bindings/regulator/regulator.txt. If this property is not present it is assumed that the supply pin is hardwired to always on.
  • 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 interface and can operate in HW only mode (no communications with the device). Currently, the devices can only be instantiated via device tree.

I2C mode

i2c0 {
         #address-cells = <1>;
         #size-cells = <0>;
         status = "okay";
         adau7118_codec: adau7118-codec@14 {
                 compatible = "adi,adau7118";
                 reg = <0x14>;
                 status = "okay";
                 adi,pdm-clk-map = <1 1 0 0>;
                 adi,decimation-ratio = <16>;   
         };
};

HW mode

/ {
         adau7118_codec: adau7118-codec@14 {
                 compatible = "adi,adau7118";
                 reg = <0x14>;
                 status = "okay";
                 IOVDD-supply = <&supply>;
                 DVDD-supply = <&supply2>;
         };
};

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

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 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

31 Jul 2012 17:53 · larsc
resources/tools-software/linux-drivers/sound/adau7118.txt · Last modified: 13 Dec 2019 14:26 by nsa