How to create a sound-card with ESAI

[Riyan]

I need to get a sound from radio-device, which use I2S protocol. The radio-device connected to the imx8 processor through ESAI. I have to registrate the radio-device and ESAI in the linux-kernel.

sound-x28 {
        compatible = "simple-audio-card";
        simple-audio-card,name = "x28-audio";
        simple-audio-card,format="i2s";
        simple-audio-card,mclk-fs = <64>;
        simple-audio-card,frame-master = <&sound2_esai>;
        simple-audio-card,bitclock-master = <&sound2_esai>;
        simple-audio-card,widgets =
                "Microphone", "Mic Jack",
                "Line", "Line In",
                "Line", "Line Out",
                "Headphone", "Headphone Jack";
        simple-audio-card,routing =
                "DMIC AIF", "DMic";
        mux-int-port = <1>;
        mux-ext-port = <4>;
        sound2_esai: simple-audio-card,cpu {
            sound-dai = <&esai1 0>;
            system-clock-frequency = <3072000>;
            dai-tdm-slot-num = <2>;
            dai-tdm-slot-width = <32>;
        };
        sound2codec: simple-audio-card,codec {
            sound-dai = <&sound>;
        };
    };
codec_x28: codec_x28 {
            #sound-dai-cells = <0>;
            compatible = "dmic,dmic-codec";
};
&esai1{
    #sound-dai-cells=<1>;
    status="okay";
};

 I don't fully understand how phandle #sound-dai-cells works. The sound-device "sound-x28" has passed a registration in the sysfs. But alsa don't see this device through aplay -l. I can't understand where I made a error in dts file. Or should I use  another driver? Please, could you show me your dts with ESAI?

[dmitry_sidorenkov]

imx8qm has esai interface with multiple (4RX and 6 TX) pins, but NXP doesn't provide even single example how to use it existing drivers look useless for example how to use esai bus with 2-3 independent codecs, which can be used in simple-audio-card driver, but this driver can't work with esai because can't setup clocking.
Also, https://source.codeaurora.org is not available.

[Riyan]

The problem hasn't been solved yet. I use a driver imx-cs42888.c as you had said. But I get faults:

[ 7.824936] fsl-asoc-card custom-sound: CPU phandle missing or invalid
[ 7.824943] fsl-asoc-card: probe of custom-sound failed with error -22
[ 7.825762] imx-cs42888 custom-sound: failed to find codec platform device

custom-sound {
compatible = "fsl,imx-audio-cs42888";
model = "custom-sound";
esai-controller = <&esai1>;
audio-codec = <&codec>;
asrc-controller = <&asrc0>;
};

codec: codec {
#sound-dai-cells = <0>;
compatible = "dmic,dmic-codec";
};

&esai1{
#sound-dai-cells=<0>;
status="okay";
};

What could I do wrong?

[igorpadykov]

Hi Riyan

one can look at sound-cs42888 with esai example on

https://source.codeaurora.org/external/imx/linux-imx/tree/arch/arm64/boot/dts/freescale/imx8qm-mek.d...

and description of audio in i.MX Linux Reference Manual​

https://www.nxp.com/design/software/embedded-software/i-mx-software/embedded-linux-for-i-mx-applicat...

nxp does not support "simple-audio-card" for esai.

Best regards
igor

[Riyan]

Hi Igor,

thank you for the answer. But My custom board have not a chip cs42888. Or are the chip and a codec not the same?

sound-cs42888 {
compatible = "fsl,imx8qm-sabreauto-cs42888",
"fsl,imx-audio-cs42888";
model = "imx-cs42888";
esai-controller = <&esai1>;
 audio-codec = <&cs42888>;
asrc-controller = <&asrc0>;
status = "okay";
};

[igorpadykov]

Hi Riyan

one can use cs42888 as example and create support for other chip, follow

Figure 27. ALSA SoC Software Architecture, sect.7.1.4.1 ASoC Driver Source Architecture

  i.MX Linux Reference Manual​

Best regards
igor

[Riyan]

Please, help me solve the problem