ARM: dts: Document the CCI PMU DT bindings

The CCI PMU can profile bus transactions at the master and slave
interfaces of the CCI. The PMU can be used to observe an aggregated
view of the bus traffic between the various components connected to the
CCI.

Introduce a binding for the CCI PMU. The PMU node will be a sub-node of
the CCI node.

Cc: [e-mail]
Cc: Lorenzo Pieralisi <[e-mail]>
Cc: Nicolas Pitre <[e-mail]>
Cc: Rob Herring <[e-mail]>
Acked-by: Stephen Warren <[e-mail]>
Acked-by: Kumar Gala <[e-mail]>
Signed-off-by: Punit Agrawal <[e-mail]>
Signed-off-by: Will Deacon <[e-mail]>

Documentation/devicetree/bindings/arm/cci.txt

···
 				    corresponding interface programming
 				    registers.
 
+	- CCI PMU node
+
+		Parent node must be CCI interconnect node.
+
+		A CCI pmu node must contain the following properties:
+
+		- compatible
+			Usage: required
+			Value type: <string>
+			Definition: must be "arm,cci-400-pmu"
+
+		- reg:
+			Usage: required
+			Value type: Integer cells. A register entry, expressed
+				    as a pair of cells, containing base and
+				    size.
+			Definition: the base address and size of the
+				    corresponding interface programming
+				    registers.
+
+		- interrupts:
+			Usage: required
+			Value type: Integer cells. Array of interrupt specifier
+				    entries, as defined in
+				    ../interrupt-controller/interrupts.txt.
+			Definition: list of counter overflow interrupts, one per
+				    counter. The interrupts must be specified
+				    starting with the cycle counter overflow
+				    interrupt, followed by counter0 overflow
+				    interrupt, counter1 overflow interrupt,...
+				    ,counterN overflow interrupt.
+
+				    The CCI PMU has an interrupt signal for each
+				    counter. The number of interrupts must be
+				    equal to the number of counters.
+
 * CCI interconnect bus masters
 
 	Description: masters in the device tree connected to a CCI port
···
 		#address-cells = <1>;
 		#size-cells = <1>;
 		reg = <0x0 0x2c090000 0 0x1000>;
-		ranges = <0x0 0x0 0x2c090000 0x6000>;
+		ranges = <0x0 0x0 0x2c090000 0x10000>;
 
 		cci_control0: slave-if@1000 {
 			compatible = "arm,cci-400-ctrl-if";
···
 			compatible = "arm,cci-400-ctrl-if";
 			interface-type = "ace";
 			reg = <0x5000 0x1000>;
+		};
+
+		pmu@9000 {
+			 compatible = "arm,cci-400-pmu";
+			 reg = <0x9000 0x5000>;
+			 interrupts = <0 101 4>,
+				      <0 102 4>,
+				      <0 103 4>,
+				      <0 104 4>,
+				      <0 105 4>;
 		};
 	};