--- zzzz-none-000/linux-4.4.60/Documentation/devicetree/bindings/serial/qcom,msm-uartdm.txt	2017-04-08 07:53:53.000000000 +0000
+++ dragonfly-4020-701/linux-4.4.60/Documentation/devicetree/bindings/serial/qcom,msm-uartdm.txt	2018-11-08 13:36:17.000000000 +0000
@@ -32,6 +32,8 @@
 - qcom,rx-crci: Identificator <u32> for Client Rate Control Interface to be
            used with RX DMA channel. Required when using DMA for reception
            with UARTDM v1.3 and bellow.
+- serial_clk: Required to set the clock rate when its not passing from boot
+            loader such as u-boot.
 
 Note: Aliases may be defined to ensure the correct ordering of the UARTs.
 The alias serialN will result in the UART being assigned port N.  If any