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| -rw-r--r-- | Documentation/devicetree/bindings/clock/corenet-clock.txt | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/clock/corenet-clock.txt b/Documentation/devicetree/bindings/clock/corenet-clock.txt new file mode 100644 index 000000000000..24711af48e30 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/corenet-clock.txt @@ -0,0 +1,134 @@ +* 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>; + ... + }; + } |