Some Samsung Exynos boards using the arm64 architecture have DW MMC controllers configured for a 32-bit data bus but a 64-bit FIFO. On these systems the 64-bit FIFO registers must be accessed in two 32-bit halves. --- .../devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml index 8dfad89c7..d025b38ca 100644 --- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml +++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml @@ -57,6 +57,13 @@ properties: force fifo watermark setting accordingly. $ref: /schemas/types.yaml#/definitions/flag + fifo-access-32bit: + description: + Specifies that this device requires accesses to its 64-bit registers + to be done as pairs of 32-bit accesses, even on architectures where + readq is available. + $ref: /schemas/types.yaml#/definitions/flag + dmas: maxItems: 1 -- 2.38.3