On 24/11/2023 08:08, Axe Yang wrote: > Add 'mediatek,tune-64-steps' option. This property will give MSDC > a chance to achieve a more optimal calibration result, thus avoiding > potential CRC issues. Documentation goes before users. > > Signed-off-by: Axe Yang <axe.yang@xxxxxxxxxxxx> > --- > Documentation/devicetree/bindings/mmc/mtk-sd.yaml | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mmc/mtk-sd.yaml b/Documentation/devicetree/bindings/mmc/mtk-sd.yaml > index 3fffa467e4e1..c33301e2ea33 100644 > --- a/Documentation/devicetree/bindings/mmc/mtk-sd.yaml > +++ b/Documentation/devicetree/bindings/mmc/mtk-sd.yaml > @@ -145,6 +145,14 @@ properties: > minimum: 0 > maximum: 7 > > + mediatek,tune-64-steps: > + $ref: /schemas/types.yaml#/definitions/flag > + description: > + Some Soc need enable 64-steps tuning for better delay value to avoid CRC issue. This scales poorly. Instead should be enum with number of tuning steps. > + If present, tune 64 steps to cover a complete clock cycle. > + If not present, tune only 32 steps. For eMMC and SD, this can also yield > + satisfactory calibration results in most cases. Best regards, Krzysztof
