dt-bindings: usb: dwc3: add reference clock period

Document the snps,ref-clock-period-ns property that describes reference
clock period when it deviates from the default set value.

Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Link: https://lore.kernel.org/r/f5ea5bc3664a98a684ad4b699a1ac610e847176f.1630389452.git.baruch@tkos.co.il
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
index 078fb78..1040d06 100644 (file)
--- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
+++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
@@ -252,6 +252,14 @@ properties:
     minimum: 0
     maximum: 0x3f
 
+  snps,ref-clock-period-ns:
+    description:
+      Value for REFCLKPER field of GUCTL register for reference clock period in
+      nanoseconds, when the hardware set default does not match the actual
+      clock.
+    minimum: 1
+    maximum: 0x3ff
+
   snps,rx-thr-num-pkt-prd:
     description:
       Periodic ESS RX packet threshold count (host mode only). Set this and