[PATCHv4 1/3] dt-bindings: mmc: synopsys-dw-mshc: document "altr,sysmgr-syscon"

[Dinh Nguyen <dinguyen@kernel.org>]

Document the optional "altr,sysmgr-syscon" binding that is used to
access the System Manager register that controls the SDMMC clock
phase.

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
---
v4: add else statement
v3: document that the "altr,sysmgr-syscon" binding is only applicable to
    "altr,socfpga-dw-mshc"
v2: document "altr,sysmgr-syscon" in the MMC section
---
 .../bindings/mmc/synopsys-dw-mshc.yaml        | 31 +++++++++++++++++--
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.yaml b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.yaml
index ae6d6fca79e2..b73324273464 100644
--- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.yaml
+++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.yaml
@@ -6,9 +6,6 @@ $schema: http://devicetree.org/meta-schemas/core.yaml#
 
 title: Synopsys Designware Mobile Storage Host Controller Binding
 
-allOf:
-  - $ref: "synopsys-dw-mshc-common.yaml#"
-
 maintainers:
   - Ulf Hansson <ulf.hansson@linaro.org>
 
@@ -38,6 +35,34 @@ properties:
       - const: biu
       - const: ciu
 
+  altr,sysmgr-syscon:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      - items:
+          - description: phandle to the sysmgr node
+          - description: register offset that controls the SDMMC clock phase
+    description:
+      Contains the phandle to System Manager block that contains
+      the SDMMC clock-phase control register. The first value is the pointer
+      to the sysmgr and the 2nd value is the register offset for the SDMMC
+      clock phase register.
+
+allOf:
+  - $ref: "synopsys-dw-mshc-common.yaml#"
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            const:
+              - altr,socfpga-dw-mshc
+    then:
+      required:
+        - altr,sysmgr-syscon
+    else:
+      properties:
+        altr,sysmgr-syscon: false
+
 required:
   - compatible
   - reg
-- 
2.25.1