diff --git a/Documentation/devicetree/bindings/mmc/arm,pl18x.yaml b/Documentation/devicetree/bindings/mmc/arm,pl18x.yaml
index fbc866d9bb2f3deaba9026b1209746cb52ef83d4..f0a44b2cfa799ac3cd761c3cc2695ee3004d53ba 100644
--- a/Documentation/devicetree/bindings/mmc/arm,pl18x.yaml
+++ b/Documentation/devicetree/bindings/mmc/arm,pl18x.yaml
@@ -53,6 +53,12 @@ properties:
         items:
           - const: arm,pl18x
           - const: arm,primecell
+      - description: Entry for STMicroelectronics variant of PL18x.
+          This dedicated compatible is used by bootloaders.
+        items:
+          - const: st,stm32-sdmmc2
+          - const: arm,pl18x
+          - const: arm,primecell
 
   clocks:
     description: One or two clocks, the "apb_pclk" and the "MCLK"