Asynchronous interrupt is a mechanism that allow SDIO devices alarm
interrupt when host stop providing clock to card. Add a DT flag to
enable this feature if it is supported by SDIO card.

Signed-off-by: Axe Yang <axe.yang@mediatek.com>
---
 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 513f3c8758aa..16fb06f88471 100644
--- a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
+++ b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
@@ -165,6 +165,11 @@ properties:
     description:
       eMMC hardware reset is supported
 
+  cap-sdio-async-irq:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      SDIO async interrupt is supported.
+
   cap-sdio-irq:
     $ref: /schemas/types.yaml#/definitions/flag
     description:
-- 
2.25.1