dt-bindings: ti: dpll: add spread spectrum support

DT bindings for enabling and adjusting spread spectrum clocking have
been added.

Signed-off-by: Dario Binacchi <dariobin@libero.it>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210606202253.31649-3-dariobin@libero.it
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Author: passgat

Documentation/devicetree/bindings/clock/ti/dpll.txt

@@ -42,6 +42,11 @@ Required properties:
 	"idlest" - contains the idle status register base address
 	"mult-div1" - contains the multiplier / divider register base address
 	"autoidle" - contains the autoidle register base address (optional)
+	"ssc-deltam" - DPLL supports spread spectrum clocking (SSC), contains
+		       the frequency spreading register base address (optional)
+	"ssc-modfreq" - DPLL supports spread spectrum clocking (SSC), contains
+		        the modulation frequency register base address
+			(optional)
   ti,am3-* dpll types do not have autoidle register
   ti,omap2-* dpll type does not support idlest / autoidle registers
 
@@ -51,6 +56,14 @@ Optional properties:
 	- ti,low-power-stop : DPLL supports low power stop mode, gating output
 	- ti,low-power-bypass : DPLL output matches rate of parent bypass clock
 	- ti,lock : DPLL locks in programmed rate
+	- ti,min-div : the minimum divisor to start from to round the DPLL
+		       target rate
+	- ti,ssc-deltam : DPLL supports spread spectrum clocking, frequency
+			  spreading in permille (10th of a percent)
+	- ti,ssc-modfreq-hz : DPLL supports spread spectrum clocking, spread
+			      spectrum modulation frequency
+	- ti,ssc-downspread : DPLL supports spread spectrum clocking, boolean
+			      to enable the downspread feature
 
 Examples:
 	dpll_core_ck: dpll_core_ck@44e00490 {
@@ -83,3 +96,10 @@ Examples:
 		clocks = <&sys_ck>, <&sys_ck>;
 		reg = <0x0500>, <0x0540>;
 	};
+
+	dpll_disp_ck: dpll_disp_ck {
+		#clock-cells = <0>;
+		compatible = "ti,am3-dpll-no-gate-clock";
+		clocks = <&sys_clkin_ck>, <&sys_clkin_ck>;
+		reg = <0x0498>, <0x0448>, <0x0454>, <0x044c>, <0x0450>;
+	};