[PATCH v3 4/4] nds32: Add document for NDS32 PMU.

[Nickhu]

The document for how to add NDS32 PMU
in devicetree.

Signed-off-by: Nickhu <nickhu@xxxxxxxxxxxxx>
---
 Documentation/devicetree/bindings/nds32/pmu.txt | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/nds32/pmu.txt

diff --git a/Documentation/devicetree/bindings/nds32/pmu.txt b/Documentation/devicetree/bindings/nds32/pmu.txt
new file mode 100644
index 000000000000..1bd15785b4ae
--- /dev/null
+++ b/Documentation/devicetree/bindings/nds32/pmu.txt
@@ -0,0 +1,17 @@
+* NDS32 Performance Monitor Units
+
+NDS32 core have a PMU for counting cpu and cache events like cache misses.
+The NDS32 PMU representation in the device tree should be done as under:
+
+Required properties:
+
+- compatible :
+	"andestech,nds32v3-pmu"
+
+- interrupts : The interrupt number for NDS32 PMU is 13.
+
+Example:
+pmu{
+	compatible = "andestech,nds32v3-pmu";
+	interrupts = <13>;
+}
-- 
2.17.0