Re: [PATCH v3 2/4] media: synopsys: hdmirx: add HDMI audio capture support

[Dmitry Osipenko <dmitry.osipenko@collabora.com>]

On 7/18/26 11:57, Igor Paunovic wrote:
> The Synopsys DesignWare HDMI RX controller extracts the audio stream
> embedded in the incoming HDMI signal and feeds it to an on-SoC I2S
> controller. Expose it as an ALSA capture device by registering the
> generic hdmi-codec as a child of the controller, so that a
> simple-audio-card in the device tree can bind the HDMI RX audio DAI.
> 
> The sample rate is recovered from the ACR N/CTS values together with the
> measured TMDS character rate. A periodic worker keeps the local audio
> reference clock locked to the source by nudging it in small ppm steps to
> hold the audio FIFO fill level near its target, which avoids FIFO
> under/overflow and the resulting dropped samples.
> 
> Signed-off-by: Igor Paunovic <royalnet026@gmail.com>
> ---
> Changes in v3:
> - restore the v1 audio teardown in remove(): audio_shutdown() already
>   stops the worker when the stream closes, so the extra flag clear
>   and trailing cancel added in v2 were redundant (Dmitry Osipenko)
> - rename the ACR read locals and add a comment documenting the
>   register byte packing
> - drop the get_dai_id stub so OF-graph cards resolve the DAI index
>   from the reg property
> 
> Changes in v2:
> - register the S/PDIF DAI so the indexes match the binding and reject
>   it with -EOPNOTSUPP until wired up (Sebastian Reichel)
> - use platform_device_register_data() and drop the fixed 32-bit DMA
>   mask (Dmitry Osipenko)
> - don't leave an ERR_PTR in audio_pdev on registration failure
> - fix teardown ordering in remove()
> - stop the worker before reprogramming shared state in hw_params()
> - look up the "audio" clock by name instead of indexing clks[1]
> - keep the worker on system_unbound_wq when re-arming
> 
>  .../platform/synopsys/hdmirx/snps_hdmirx.c    | 271 ++++++++++++++++++
>  .../platform/synopsys/hdmirx/snps_hdmirx.h    |   8 +
>  2 files changed, 279 insertions(+)

Works well on 5b, thanks. Only one additional review comment:

Please update hdmirx_suspend() to return -EBUSY if audio_streaming=true.

```
static __maybe_unused int hdmirx_suspend(struct device *dev)
{
	struct snps_hdmirx_dev *hdmirx_dev = dev_get_drvdata(dev);

	if (READ_ONCE((hdmirx_dev->audio_streaming)))
		return -EBUSY;
```

-- 
Best regards,
Dmitry