On 16/02/2023 11:15, Claudiu.Beznea@xxxxxxxxxxxxx wrote: > On 16.02.2023 12:04, Krzysztof Kozlowski wrote: >> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >> >> On 14/02/2023 17:14, Claudiu Beznea wrote: >>> Add microchip,startup-delay-us binding to let PDMC users to specify >>> startup delay. >>> >>> Signed-off-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx> >>> --- >>> .../devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml | 6 ++++++ >>> 1 file changed, 6 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml b/Documentation/devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml >>> index c4cf1e5ab84b..9b40268537cb 100644 >>> --- a/Documentation/devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml >>> +++ b/Documentation/devicetree/bindings/sound/microchip,sama7g5-pdmc.yaml >>> @@ -67,6 +67,12 @@ properties: >>> maxItems: 4 >>> uniqueItems: true >>> >>> + microchip,startup-delay-us: >>> + description: | >>> + Specifies the delay in microseconds that needs to be applied after >>> + enabling the PDMC microphones to avoid unwanted noise due to microphones >>> + not being ready. >> >> Is this some hardware delay? Or OS? If OS, why Linux specific delay is >> put into DT? > > It's the delay used in software workaround that IP needs to filter noises. Then this sounds like OS? Linux related properties usually do not belong to DT. > The IP is not fully featured to do this kind of filtering on its own thus > this software workaround. This delay may depend on used microphones thus > for different kind of setups (PDMC + different microphones) I introduced > this in DT. I understand your driver needs delay and I am not questioning this. I am questioning why this is suitable for DT? Best regards, Krzysztof
