dt-bindings: snps, dw-apb-ssi: Add sparx5 support, plus rx-sample-delay-ns property

This has the following changes for the snps,dw-apb-ss DT bindings:

- Add "microchip,sparx5-spi" as the compatible for the Sparx5 SoC
  controller

- Add the property "rx-sample-delay-ns"

Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200824203010.2033-5-lars.povlsen@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml

@@ -36,6 +36,8 @@ properties:
               - mscc,ocelot-spi
               - mscc,jaguar2-spi
           - const: snps,dw-apb-ssi
+      - description: Microchip Sparx5 SoC SPI Controller
+        const: microchip,sparx5-spi
       - description: Amazon Alpine SPI Controller
         const: amazon,alpine-dw-apb-ssi
       - description: Renesas RZ/N1 SPI Controller
@@ -93,6 +95,12 @@ properties:
       - const: tx
       - const: rx
 
+  rx-sample-delay-ns:
+    default: 0
+    description: Default value of the rx-sample-delay-ns property.
+      This value will be used if the property is not explicitly defined
+      for a SPI slave device. See below.
+
 patternProperties:
   "^.*@[0-9a-f]+$":
     type: object
@@ -107,6 +115,13 @@ patternProperties:
       spi-tx-bus-width:
         const: 1
 
+      rx-sample-delay-ns:
+        description: SPI Rx sample delay offset, unit is nanoseconds.
+          The delay from the default sample time before the actual
+          sample of the rxd input signal occurs. The "rx_sample_delay"
+          is an optional feature of the designware controller, and the
+          upper limit is also subject to controller configuration.
+
 unevaluatedProperties: false
 
 required:
@@ -129,5 +144,11 @@ examples:
       num-cs = <2>;
       cs-gpios = <&gpio0 13 0>,
                  <&gpio0 14 0>;
+      rx-sample-delay-ns = <3>;
+      spi-flash@1 {
+        compatible = "spi-nand";
+        reg = <1>;
+        rx-sample-delay-ns = <7>;
+      };
     };
 ...