| * Clock Block on Freescale CoreNet Platforms | |
| Freescale CoreNet chips take primary clocking input from the external | |
| SYSCLK signal. The SYSCLK input (frequency) is multiplied using | |
| multiple phase locked loops (PLL) to create a variety of frequencies | |
| which can then be passed to a variety of internal logic, including | |
| cores and peripheral IP blocks. | |
| Please refer to the Reference Manual for details. | |
| 1. Clock Block Binding | |
| Required properties: | |
| - compatible: Should contain a specific clock block compatible string | |
| and a single chassis clock compatible string. | |
| Clock block strings include, but not limited to, one of the: | |
| * "fsl,p2041-clockgen" | |
| * "fsl,p3041-clockgen" | |
| * "fsl,p4080-clockgen" | |
| * "fsl,p5020-clockgen" | |
| * "fsl,p5040-clockgen" | |
| * "fsl,t4240-clockgen" | |
| * "fsl,b4420-clockgen" | |
| * "fsl,b4860-clockgen" | |
| Chassis clock strings include: | |
| * "fsl,qoriq-clockgen-1.0": for chassis 1.0 clocks | |
| * "fsl,qoriq-clockgen-2.0": for chassis 2.0 clocks | |
| - reg: Describes the address of the device's resources within the | |
| address space defined by its parent bus, and resource zero | |
| represents the clock register set | |
| - clock-frequency: Input system clock frequency | |
| Recommended properties: | |
| - ranges: Allows valid translation between child's address space and | |
| parent's. Must be present if the device has sub-nodes. | |
| - #address-cells: Specifies the number of cells used to represent | |
| physical base addresses. Must be present if the device has | |
| sub-nodes and set to 1 if present | |
| - #size-cells: Specifies the number of cells used to represent | |
| the size of an address. Must be present if the device has | |
| sub-nodes and set to 1 if present | |
| 2. Clock Provider/Consumer Binding | |
| Most of the bindings are from the common clock binding[1]. | |
| [1] Documentation/devicetree/bindings/clock/clock-bindings.txt | |
| Required properties: | |
| - compatible : Should include one of the following: | |
| * "fsl,qoriq-core-pll-1.0" for core PLL clocks (v1.0) | |
| * "fsl,qoriq-core-pll-2.0" for core PLL clocks (v2.0) | |
| * "fsl,qoriq-core-mux-1.0" for core mux clocks (v1.0) | |
| * "fsl,qoriq-core-mux-2.0" for core mux clocks (v2.0) | |
| * "fsl,qoriq-sysclk-1.0": for input system clock (v1.0). | |
| It takes parent's clock-frequency as its clock. | |
| * "fsl,qoriq-sysclk-2.0": for input system clock (v2.0). | |
| It takes parent's clock-frequency as its clock. | |
| - #clock-cells: From common clock binding. The number of cells in a | |
| clock-specifier. Should be <0> for "fsl,qoriq-sysclk-[1,2].0" | |
| clocks, or <1> for "fsl,qoriq-core-pll-[1,2].0" clocks. | |
| For "fsl,qoriq-core-pll-[1,2].0" clocks, the single | |
| clock-specifier cell may take the following values: | |
| * 0 - equal to the PLL frequency | |
| * 1 - equal to the PLL frequency divided by 2 | |
| * 2 - equal to the PLL frequency divided by 4 | |
| Recommended properties: | |
| - clocks: Should be the phandle of input parent clock | |
| - clock-names: From common clock binding, indicates the clock name | |
| - clock-output-names: From common clock binding, indicates the names of | |
| output clocks | |
| - reg: Should be the offset and length of clock block base address. | |
| The length should be 4. | |
| Example for clock block and clock provider: | |
| / { | |
| clockgen: global-utilities@e1000 { | |
| compatible = "fsl,p5020-clockgen", "fsl,qoriq-clockgen-1.0"; | |
| ranges = <0x0 0xe1000 0x1000>; | |
| clock-frequency = <133333333>; | |
| reg = <0xe1000 0x1000>; | |
| #address-cells = <1>; | |
| #size-cells = <1>; | |
| sysclk: sysclk { | |
| #clock-cells = <0>; | |
| compatible = "fsl,qoriq-sysclk-1.0"; | |
| clock-output-names = "sysclk"; | |
| } | |
| pll0: pll0@800 { | |
| #clock-cells = <1>; | |
| reg = <0x800 0x4>; | |
| compatible = "fsl,qoriq-core-pll-1.0"; | |
| clocks = <&sysclk>; | |
| clock-output-names = "pll0", "pll0-div2"; | |
| }; | |
| pll1: pll1@820 { | |
| #clock-cells = <1>; | |
| reg = <0x820 0x4>; | |
| compatible = "fsl,qoriq-core-pll-1.0"; | |
| clocks = <&sysclk>; | |
| clock-output-names = "pll1", "pll1-div2"; | |
| }; | |
| mux0: mux0@0 { | |
| #clock-cells = <0>; | |
| reg = <0x0 0x4>; | |
| compatible = "fsl,qoriq-core-mux-1.0"; | |
| clocks = <&pll0 0>, <&pll0 1>, <&pll1 0>, <&pll1 1>; | |
| clock-names = "pll0", "pll0-div2", "pll1", "pll1-div2"; | |
| clock-output-names = "cmux0"; | |
| }; | |
| mux1: mux1@20 { | |
| #clock-cells = <0>; | |
| reg = <0x20 0x4>; | |
| compatible = "fsl,qoriq-core-mux-1.0"; | |
| clocks = <&pll0 0>, <&pll0 1>, <&pll1 0>, <&pll1 1>; | |
| clock-names = "pll0", "pll0-div2", "pll1", "pll1-div2"; | |
| clock-output-names = "cmux1"; | |
| }; | |
| }; | |
| } | |
| Example for clock consumer: | |
| / { | |
| cpu0: PowerPC,e5500@0 { | |
| ... | |
| clocks = <&mux0>; | |
| ... | |
| }; | |
| } |