dts: bindings: serial: nrf-uarte: Add timer property

Timer property indicates which TIMER instance should be used for byte counting. If timer property is present then given instance is using TIMER to count received bytes. Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>

Author: nordic-krch

dts/bindings/serial/nordic,nrf-uarte.yaml

@@ -24,3 +24,11 @@ properties:
  type: boolean
  description: |
  UARTE allows usage of cross domain pins with constant latency mode required.
+
+ timer:
+ type: phandle
+ description: |
+ Timer instance used to count received bytes. Due to issues with frame timeout
+ feature it is required to reliably receive data in cases where flow control
+ is not used and new byte can appear on the line when frame timeout expires
+ but before it is handled.