QE: Add ucc hdlc document to bindings

Add ucc hdlc document to
Documentation/devicetree/bindings/powerpc/fsl/cpm_qe/network.txt

Signed-off-by: Zhao Qiang <qiang.zhao@nxp.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Scott Wood <oss@buserror.net>

Documentation/devicetree/bindings/powerpc/fsl/cpm_qe/network.txt

@@ -41,3 +41,84 @@ Example:
 		fsl,mdio-pin = <12>;
 		fsl,mdc-pin = <13>;
 	};
+
+* HDLC
+
+Currently defined compatibles:
+- fsl,ucc-hdlc
+
+Properties for fsl,ucc-hdlc:
+- rx-clock-name
+- tx-clock-name
+	Usage: required
+	Value type: <string>
+	Definition : Must be "brg1"-"brg16" for internal clock source,
+		     Must be "clk1"-"clk24" for external clock source.
+
+- fsl,tdm-interface
+	Usage: optional
+	Value type: <empty>
+	Definition : Specify that hdlc is based on tdm-interface
+
+The property below is dependent on fsl,tdm-interface:
+- fsl,rx-sync-clock
+	Usage: required
+	Value type: <string>
+	Definition : Must be "none", "rsync_pin", "brg9-11" and "brg13-15".
+
+- fsl,tx-sync-clock
+	Usage: required
+	Value type: <string>
+	Definition : Must be "none", "tsync_pin", "brg9-11" and "brg13-15".
+
+- fsl,tdm-framer-type
+	Usage: required for tdm interface
+	Value type: <string>
+	Definition : "e1" or "t1".Now e1 and t1 are used, other framer types
+		     are not supported.
+
+- fsl,tdm-id
+	Usage: required for tdm interface
+	Value type: <u32>
+	Definition : number of TDM ID
+
+- fsl,tx-timeslot-mask
+- fsl,rx-timeslot-mask
+	Usage: required for tdm interface
+	Value type: <u32>
+	Definition : time slot mask for TDM operation. Indicates which time
+		     slots used for transmitting and receiving.
+
+- fsl,siram-entry-id
+	Usage: required for tdm interface
+	Value type: <u32>
+	Definition : Must be 0,2,4...64. the number of TDM entry.
+
+- fsl,tdm-internal-loopback
+	usage: optional for tdm interface
+	value type: <empty>
+	Definition : Internal loopback connecting on TDM layer.
+
+Example for tdm interface:
+
+	ucc@2000 {
+		compatible = "fsl,ucc-hdlc";
+		rx-clock-name = "clk8";
+		tx-clock-name = "clk9";
+		fsl,rx-sync-clock = "rsync_pin";
+		fsl,tx-sync-clock = "tsync_pin";
+		fsl,tx-timeslot-mask = <0xfffffffe>;
+		fsl,rx-timeslot-mask = <0xfffffffe>;
+		fsl,tdm-framer-type = "e1";
+		fsl,tdm-id = <0>;
+		fsl,siram-entry-id = <0>;
+		fsl,tdm-interface;
+	};
+
+Example for hdlc without tdm interface:
+
+	ucc@2000 {
+		compatible = "fsl,ucc-hdlc";
+		rx-clock-name = "brg1";
+		tx-clock-name = "brg1";
+	};