dt-bindings: PCI: brcmstb: add optional property - "brcm,tperst-clk-ms"

This property can be used to delay deassertion of external fundamental
reset, which may be useful for endpoints that require an extended time for
internal setup to complete.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

Author: P33M

Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml

@@ -130,6 +130,14 @@ properties:
       - const: bridge
       - const: swinit
 
+  brcm,tperst-clk-ms:
+    category: optional
+    type: int
+    description: u32 giving the number of milliseconds to extend
+      the time between internal release of fundamental reset and
+      the deassertion of the external PERST# pin. This has the
+      effect of increasing the Tperst_clk phase of link init.
+
 required:
   - compatible
   - reg