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- * 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.
- All references to "1.0" and "2.0" refer to the QorIQ chassis version to
- which the chip complies.
- Chassis Version Example Chips
- --------------- -------------
- 1.0 p4080, p5020, p5040
- 2.0 t4240, b4860, t1040
- 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>;
- ...
- };
- }
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