1 ================== 1 ==================
2 C-SKY CPU Bindings 2 C-SKY CPU Bindings
3 ================== 3 ==================
4 4
5 The device tree allows to describe the layout 5 The device tree allows to describe the layout of CPUs in a system through
6 the "cpus" node, which in turn contains a numb 6 the "cpus" node, which in turn contains a number of subnodes (ie "cpu")
7 defining properties for every cpu. 7 defining properties for every cpu.
8 8
9 Only SMP system need to care about the cpus no 9 Only SMP system need to care about the cpus node and single processor
10 needn't define cpus node at all. 10 needn't define cpus node at all.
11 11
12 ===================================== 12 =====================================
13 cpus and cpu node bindings definition 13 cpus and cpu node bindings definition
14 ===================================== 14 =====================================
15 15
16 - cpus node 16 - cpus node
17 17
18 Description: Container of cpu nodes 18 Description: Container of cpu nodes
19 19
20 The node name must be "cpus". 20 The node name must be "cpus".
21 21
22 A cpus node must define the following 22 A cpus node must define the following properties:
23 23
24 - #address-cells 24 - #address-cells
25 Usage: required 25 Usage: required
26 Value type: <u32> 26 Value type: <u32>
27 Definition: must be set to 1 27 Definition: must be set to 1
28 - #size-cells 28 - #size-cells
29 Usage: required 29 Usage: required
30 Value type: <u32> 30 Value type: <u32>
31 Definition: must be set to 0 31 Definition: must be set to 0
32 32
33 - cpu node 33 - cpu node
34 34
35 Description: Describes one of SMP core 35 Description: Describes one of SMP cores
36 36
37 PROPERTIES 37 PROPERTIES
38 38
39 - device_type 39 - device_type
40 Usage: required 40 Usage: required
41 Value type: <string> 41 Value type: <string>
42 Definition: must be "cpu" 42 Definition: must be "cpu"
43 - reg 43 - reg
44 Usage: required 44 Usage: required
45 Value type: <u32> 45 Value type: <u32>
46 Definition: CPU index 46 Definition: CPU index
47 - compatible: 47 - compatible:
48 Usage: required 48 Usage: required
49 Value type: <string> 49 Value type: <string>
50 Definition: must contain "csky 50 Definition: must contain "csky", eg:
51 "csky,610" 51 "csky,610"
52 "csky,807" 52 "csky,807"
53 "csky,810" 53 "csky,810"
54 "csky,860" 54 "csky,860"
55 55
56 Example: 56 Example:
57 -------- 57 --------
58 58
59 cpus { 59 cpus {
60 #address-cells = <1>; 60 #address-cells = <1>;
61 #size-cells = <0>; 61 #size-cells = <0>;
62 cpu@0 { 62 cpu@0 {
63 device_type = "cpu"; 63 device_type = "cpu";
64 reg = <0>; 64 reg = <0>;
65 status = "ok"; 65 status = "ok";
66 }; 66 };
67 67
68 cpu@1 { 68 cpu@1 {
69 device_type = "cpu"; 69 device_type = "cpu";
70 reg = <1>; 70 reg = <1>;
71 status = "ok"; 71 status = "ok";
72 }; 72 };
73 }; 73 };
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