> On 22/02/2023 12:39, Chancel Liu wrote: > > This property specifies power up to audio out time. It's necessary > > beacause this device has to wait some time before ready to output audio > > typo... run spellcheck, also on the subject > > > after MCLK, BCLK and MUTE=1 are enabled. For more details about the > > timing constraints, please refer to WTN0302 on > > > > > > Signed-off-by: Chancel Liu <chancel.liu@xxxxxxx> > > --- > > .../devicetree/bindings/sound/wlf,wm8524.yaml | 10 > ++++++++++ > > 1 file changed, 10 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/sound/wlf,wm8524.yaml > b/Documentation/devicetree/bindings/sound/wlf,wm8524.yaml > > index 09c54cc7de95..54b4da5470e4 100644 > > --- a/Documentation/devicetree/bindings/sound/wlf,wm8524.yaml > > +++ b/Documentation/devicetree/bindings/sound/wlf,wm8524.yaml > > @@ -21,6 +21,15 @@ properties: > > description: > > a GPIO spec for the MUTE pin. > > > > + wlf,power-up-delay-ms: > > + maximum: 1500 > > maximum is 1003. Where do you see 1500? > > minimum: 82 > Yes, you are absolutely right. From the power up to audio out timing table in WTN0302, the minimum number is 82 and the maximum is 1003. Consider the following possibilities: 1. These timings may depend on the system design 2. These timings may be simulated results 3. These timings may be the minimum values I set a larger value trying to extend the time. The larger value of course introduces unwanted time delay but it benefits on avoiding beginning audio lost. I also did some tests on a board. If I want to work on 48KHZ sample rate and 512FS, the recommended value is 143. But the test result showed 143ms is not enough. I increased the value to 500ms and could hear the beginning sound. Maybe it's a better choice to let DT set the suitable value? Is there a similar situation before? > > + default: 100 > > + description: > > + Power up sequency delay time in millisecond. It specifies power up to > > typo: sequence? > Sorry. I must avoid these spelling mistakes. > > + audio out time. For more details about the timing constraints of this > > + device, please refer to WTN0302 on > > + > > According to WTN0302 this might or might not include regulator > ramp-up-delay. You should clearly indicate which part of it this delay > is to not mix up with ramp up. IOW, mention exactly from where the value > comes (e.g. Δt POWER UP TO AUDIO OUT TIMING table, depending on sampling > clock rate). Otherwise you introduce quite loose property which will be > including regulator ramp up in some cases... > > Best regards, > Krzysztof Yes. This property is designed for power up to audio out timing. I need to clearly point this out. Thank you very much for your suggestions! Regards, Chancel Liu
