[PATCH 1/2] dt-bindings: mmc: add no-mmc-hs400 flag

[Lucas Stach]

HS400 requires a data strobe line in addition to the other MMC signal
lines, so if a board design neglects to wire up this signal, HS400 mode
is no available, even if both the controller and the eMMC are claiming
to support this mode. Add a DT flag to allow boards to disable the
HS400 support in this case.

Signed-off-by: Lucas Stach <dev at lynxeye.de>
---
 Documentation/devicetree/bindings/mmc/mmc-controller.yaml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
index e141330c1114..ac80d09df3a9 100644
--- a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
+++ b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
@@ -220,6 +220,11 @@ properties:
     description:
       eMMC HS400 enhanced strobe mode is supported
 
+  no-mmc-hs400:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      All eMMC HS400 modes are not supported.
+
   dsr:
     description:
       Value the card Driver Stage Register (DSR) should be programmed
-- 
2.31.1