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authorTang Yuantian <yuantian.tang@freescale.com>2014-01-13 12:16:35 +0400
committerScott Wood <scottwood@freescale.com>2014-01-18 05:01:27 +0400
commit4b3cbc82a04485f6400cb5b227798daaa8512a23 (patch)
treeb6817c7007c109b4686abd746504615bb2475005 /Documentation
parent9841c79c890cf7ef9ffa2c86c9924113c9a88244 (diff)
downloadlinux-4b3cbc82a04485f6400cb5b227798daaa8512a23.tar.xz
clk: corenet: Adds the clock binding
Adds the clock bindings for Freescale PowerPC CoreNet platforms Signed-off-by: Tang Yuantian <Yuantian.Tang@freescale.com> Signed-off-by: Li Yang <leoli@freescale.com> [scottwood@freescale.com: fixed clock-frequency in example] Signed-off-by: Scott Wood <scottwood@freescale.com>
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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.
+
+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>;
+ ...
+ };
+ }