| Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame^] | 1 | ================== |
| 2 | C-SKY CPU Bindings |
| 3 | ================== |
| 4 | |
| 5 | The device tree allows to describe the layout of CPUs in a system through |
| 6 | the "cpus" node, which in turn contains a number of subnodes (ie "cpu") |
| 7 | defining properties for every cpu. |
| 8 | |
| 9 | Only SMP system need to care about the cpus node and single processor |
| 10 | needn't define cpus node at all. |
| 11 | |
| 12 | ===================================== |
| 13 | cpus and cpu node bindings definition |
| 14 | ===================================== |
| 15 | |
| 16 | - cpus node |
| 17 | |
| 18 | Description: Container of cpu nodes |
| 19 | |
| 20 | The node name must be "cpus". |
| 21 | |
| 22 | A cpus node must define the following properties: |
| 23 | |
| 24 | - #address-cells |
| 25 | Usage: required |
| 26 | Value type: <u32> |
| 27 | Definition: must be set to 1 |
| 28 | - #size-cells |
| 29 | Usage: required |
| 30 | Value type: <u32> |
| 31 | Definition: must be set to 0 |
| 32 | |
| 33 | - cpu node |
| 34 | |
| 35 | Description: Describes one of SMP cores |
| 36 | |
| 37 | PROPERTIES |
| 38 | |
| 39 | - device_type |
| 40 | Usage: required |
| 41 | Value type: <string> |
| 42 | Definition: must be "cpu" |
| 43 | - reg |
| 44 | Usage: required |
| 45 | Value type: <u32> |
| 46 | Definition: CPU index |
| 47 | - compatible: |
| 48 | Usage: required |
| 49 | Value type: <string> |
| 50 | Definition: must contain "csky", eg: |
| 51 | "csky,610" |
| 52 | "csky,807" |
| 53 | "csky,810" |
| 54 | "csky,860" |
| 55 | |
| 56 | Example: |
| 57 | -------- |
| 58 | |
| 59 | cpus { |
| 60 | #address-cells = <1>; |
| 61 | #size-cells = <0>; |
| 62 | cpu@0 { |
| 63 | device_type = "cpu"; |
| 64 | reg = <0>; |
| 65 | status = "ok"; |
| 66 | }; |
| 67 | |
| 68 | cpu@1 { |
| 69 | device_type = "cpu"; |
| 70 | reg = <1>; |
| 71 | status = "ok"; |
| 72 | }; |
| 73 | }; |