[PATCH 1/2] dt-bindings: mmc: dw-mshc-common: add option for configuring DMA threshold

[Kaustabh Chakraborty]

Some controllers, such as certain Exynos SDIO ones, are unable to
perform DMA transfers of small amount of bytes properly. Add a property
to configure the DMA transfer threshold.

Signed-off-by: Kaustabh Chakraborty <kauschluss@xxxxxxxxxxx>
---
 .../devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml          | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
index 6f11b2adf1036..1693277957a91 100644
--- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
+++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
@@ -57,6 +57,14 @@ properties:
       force fifo watermark setting accordingly.
     $ref: /schemas/types.yaml#/definitions/flag
 
+  dma-threshold-bytes:
+    description:
+      DMA transfer takes place only if the transfer size is equal to or greater
+      than the number of bytes defined by the threshold value. Some controllers are
+      unable to perform the DMA transfer properly with small amounts of data.
+      This option allows to configure the threshold up to a comfortable value.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
   dmas:
     maxItems: 1
 

-- 
2.53.0