xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/csky/cpus.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun==================
2*4882a593SmuzhiyunC-SKY CPU Bindings
3*4882a593Smuzhiyun==================
4*4882a593Smuzhiyun
5*4882a593SmuzhiyunThe device tree allows to describe the layout of CPUs in a system through
6*4882a593Smuzhiyunthe "cpus" node, which in turn contains a number of subnodes (ie "cpu")
7*4882a593Smuzhiyundefining properties for every cpu.
8*4882a593Smuzhiyun
9*4882a593SmuzhiyunOnly SMP system need to care about the cpus node and single processor
10*4882a593Smuzhiyunneedn't define cpus node at all.
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun=====================================
13*4882a593Smuzhiyuncpus and cpu node bindings definition
14*4882a593Smuzhiyun=====================================
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun- cpus node
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun	Description: Container of cpu nodes
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun	The node name must be "cpus".
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun	A cpus node must define the following properties:
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun	- #address-cells
25*4882a593Smuzhiyun		Usage: required
26*4882a593Smuzhiyun		Value type: <u32>
27*4882a593Smuzhiyun		Definition: must be set to 1
28*4882a593Smuzhiyun	- #size-cells
29*4882a593Smuzhiyun		Usage: required
30*4882a593Smuzhiyun		Value type: <u32>
31*4882a593Smuzhiyun		Definition: must be set to 0
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun- cpu node
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun	Description: Describes one of SMP cores
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun	PROPERTIES
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun	- device_type
40*4882a593Smuzhiyun		Usage: required
41*4882a593Smuzhiyun		Value type: <string>
42*4882a593Smuzhiyun		Definition: must be "cpu"
43*4882a593Smuzhiyun	- reg
44*4882a593Smuzhiyun		Usage: required
45*4882a593Smuzhiyun		Value type: <u32>
46*4882a593Smuzhiyun		Definition: CPU index
47*4882a593Smuzhiyun	- compatible:
48*4882a593Smuzhiyun		Usage: required
49*4882a593Smuzhiyun		Value type: <string>
50*4882a593Smuzhiyun		Definition: must contain "csky", eg:
51*4882a593Smuzhiyun			"csky,610"
52*4882a593Smuzhiyun			"csky,807"
53*4882a593Smuzhiyun			"csky,810"
54*4882a593Smuzhiyun			"csky,860"
55*4882a593Smuzhiyun
56*4882a593SmuzhiyunExample:
57*4882a593Smuzhiyun--------
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun	cpus {
60*4882a593Smuzhiyun		#address-cells = <1>;
61*4882a593Smuzhiyun		#size-cells = <0>;
62*4882a593Smuzhiyun		cpu@0 {
63*4882a593Smuzhiyun			device_type = "cpu";
64*4882a593Smuzhiyun			reg = <0>;
65*4882a593Smuzhiyun			status = "ok";
66*4882a593Smuzhiyun		};
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun		cpu@1 {
69*4882a593Smuzhiyun			device_type = "cpu";
70*4882a593Smuzhiyun			reg = <1>;
71*4882a593Smuzhiyun			status = "ok";
72*4882a593Smuzhiyun		};
73*4882a593Smuzhiyun	};
74