+Required dai-link subnodes:
+
+- cpu : CPU sub-node
+- codec : CODEC sub-node
+
+Optional dai-link subnode properties:
+
+- format : CPU/CODEC common audio format.
+ "i2s", "right_j", "left_j" , "dsp_a"
+ "dsp_b", "ac97", "pdm", "msb", "lsb"
+- frame-master : Indicates dai-link frame master.
+ phandle to a cpu or codec subnode.
+- bitclock-master : Indicates dai-link bit clock master.
+ phandle to a cpu or codec subnode.
+- bitclock-inversion : bool property. Add this if the
+ dai-link uses bit clock inversion.
+- frame-inversion : bool property. Add this if the
+ dai-link uses frame clock inversion.
+
+For backward compatibility the frame-master and bitclock-master
+properties can be used as booleans in codec subnode to indicate if the
+codec is the dai-link frame or bit clock master. In this case there
+should be no dai-link node, the same properties should not be present
+at sound-node level, and the bitclock-inversion and frame-inversion
+properties should also be placed in the codec node if needed.