This patch adds the documentation to describe that how to add cpu nodes in
dts for SMP.

Signed-off-by: Guo Ren <redacted>
Cc: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/csky/cpus.txt | 70 +++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/csky/cpus.txt

diff --git a/Documentation/devicetree/bindings/csky/cpus.txt b/Documentation/devicetree/bindings/csky/cpus.txt
new file mode 100644
index 0000000..ee3901d
--- /dev/null
+++ b/Documentation/devicetree/bindings/csky/cpus.txt

@@ -0,0 +1,70 @@
+==================
+C-SKY CPU Bindings
+==================
+
+The device tree allows to describe the layout of CPUs in a system through
+the "cpus" node, which in turn contains a number of subnodes (ie "cpu")
+defining properties for every cpu.
+
+Only SMP system need to care about the cpus node and single processor
+needn't define cpus node at all.
+
+=====================================
+cpus and cpu node bindings definition
+=====================================
+
+- cpus node
+
+        Description: Container of cpu nodes
+
+        The node name must be "cpus".
+
+        A cpus node must define the following properties:
+
+        - #address-cells
+                Usage: required
+                Value type: <u32>
+                Definition: must be set to 1
+        - #size-cells
+                Usage: required
+                Value type: <u32>
+                Definition: must be set to 0
+
+- cpu node
+
+        Description: Describes one of SMP cores
+
+        PROPERTIES
+