[PATCH v2 1/2] dt-bindings: mmc: mtk-sd: add tuning steps related property

Axe Yang
2023-11-28T07:02:02Z

Add 'mediatek,tuning-steps' setting. This property will give MSDC
a chance to extend tuning steps up to 64. With more tuning steps,
MSDC may achieve a more optimal calibration result, thus avoiding
potential CRC issues.

Signed-off-by: Axe Yang <axe.yang@mediatek.com>
---
Documentation/devicetree/bindings/mmc/mtk-sd.yaml | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/mtk-sd.yaml b/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
index 3fffa467e4e1..c532ec92d2d9 100644
--- a/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
+++ b/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
@@ -145,6 +145,15 @@ properties:
minimum: 0
maximum: 7

+ mediatek,tuning-step:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Some SoCs need extend tuning step for better delay value to avoid CRC issue.
+ If not present, default tuning step is 32. For eMMC and SD, this can yield
+ satisfactory calibration results in most cases.
+ enum: [32, 64]
+ default: 32
+
resets:
maxItems: 1

--
2.25.1