[IMX93] How to config device tree for SPDIF bind with HDMI Audio

[charleshuang]

Hi NXP Team,

As title, we connect SPDIF output "MX93_PAD_GPIO_IO23__SPDIF_OUT" to ADV7535 audio on our board. So, for this purpose, how should we configure the device tree?

[charleshuang]

Hi @jimmychan ,

Yes, the imx93 does not directly support HDMI video/audio.

Our board is MIPI to HDMI, and the SPDIF_OUT is connected to the bridge IC.

In theory, it should work. Please refer to the attached document for the device tree modifications.

And please help us confirm where the issue might be? Thank you!

[jimmychan]

What is the issue you met? No sound come out?

When you test, do you unblank the HDMI?

FYI. https://community.nxp.com/t5/i-MX-Processors/IMX8MP-HDMI-audio-no-sound/td-p/1939886

[weikeng-jimmy]

Hi Sir,

My customer would to know how to achieve this function as figure (hdmi audio).

We refer Beacon development board setting and use "i2s" audio card format can work normally. (imx8mm-beacon-kit.dts)

sound-hdmi {
compatible = "simple-audio-card";
simple-audio-card,name = "sound-hdmi";
simple-audio-card,format = "i2s";

simple-audio-card,cpu {
sound-dai = <&sai5>;
system-clock-direction-out;
};

simple-audio-card,codec {
sound-dai = <&adv_bridge>;
};
};

Can you give we some suggestion for "spdif" setting. Thanks !

sound-hdmi {
compatible = "simple-audio-card";
simple-audio-card,name = "sound-hdmi";

#address-cells = <1>;
#size-cells = <0>;

simple-audio-card,cpu {
sound-dai = <&xcvr>; // sound-dai = <&sai5>;
};

simple-audio-card,codec {
sound-dai = <&adv7535>;
};
};

error log message as below.

[ 3.134115] asoc-simple-card sound-hdmi: control 3:0:0:IEC958 Playback Default:0 is already present
[ 3.143195] hdmi-audio-codec hdmi-audio-codec.1.auto: ASoC: error at snd_soc_pcm_dai_new on spdif-hifi: -16

[charleshuang]

Hi @jimmychan 

Thank your reply, I tried 'unblank the HDMI' but it look like no use.

Yes, there is no audio output.
I tested by using `gplay` to play a AV file.
The SPDIF_OUT has a signal, but there is no sound heard from the HDMI panel.

And my sound card information as below :

root@imx93afee320a1:~# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: imxaudioxcvr [imx-audio-xcvr], device 0: XCVR PCM snd-soc-dummy-dai-0 [XCVR PCM snd-soc-dummy-dai-0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: sgtl5000 [sgtl5000], device 0: HiFi sgtl5000-0 [HiFi sgtl5000-0]
Subdevices: 1/1
Subdevice #0: subdevice #0

The document of `xcvr` say it support HDMI Audio, is there anything that we need to pay attention to?
https://github.com/nxp-imx/linux-imx/blob/lf-6.1.36-2.1.0/Documentation/devicetree/bindings/sound/fs...

[jimmychan]

For your reference, the attachment is an example of spdif in dts.

[weikeng-jimmy]

Hi Jimmy,                                                                                                                                                               Thanks for your support. The imx93-11x11-frdm-aud-hat.dts have xcvr setting same as original imx93 dts file. Can you help to provide spdif access bridge definition in dts as below example.

https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next/+/refs/heads/akpm-base/Docu...

sound {
compatible = "simple-audio-card";
simple-audio-card,name = "Cubox Audio";

#address-cells = <1>;
#size-cells = <0>;

simple-audio-card,dai-link@0 { /* I2S - HDMI */
reg = <0>;
format = "i2s";
cpu {
sound-dai = <&audio0>;
};
codec {
sound-dai = <&tda998x0>;
};
};

simple-audio-card,dai-link@1 { /* S/PDIF - HDMI */
reg = <1>;
cpu {
sound-dai = <&audio1>;
};
codec {
sound-dai = <&tda998x1>;
};
};

simple-audio-card,dai-link@2 { /* S/PDIF - S/PDIF */
reg = <2>;
cpu {
sound-dai = <&audio2>;
};
codec {
sound-dai = <&spdif_codec>;
};
};
};

[jimmychan]

Hello,

I got the AE reply. The define of SPDIF in the example "imx93-11x11-frdm-aud-hat.dts " is almost the same with the one on i.mx93-11x11-evk.dts. The attachment is the imx93-11x11-frdm.dts that the AE used. 

Best regards,

Jimmy

[jimmychan]

"The SPDIF_OUT has a signal, but there is no sound heard from the HDMI panel."

Have you try the "alsamixer" to tune the volume?

[jimmychan]

According to the release notes, i.MX93 is not support the HDMI audio.

https://www.nxp.com/docs/en/release-note/IMX_LINUX_RELEASE_NOTES.pdf