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* Renesas Clock Pulse Generator / Module Standby and Software Reset
On Renesas ARM SoCs (SH/R-Mobile, R-Car, RZ), the CPG (Clock Pulse Generator)
and MSSR (Module Standby and Software Reset) blocks are intimately connected,
and share the same register block.
They provide the following functionalities:
- The CPG block generates various core clocks,
- The MSSR block provides two functions:
1. Module Standby, providing a Clock Domain to control the clock supply
to individual SoC devices,
2. Reset Control, to perform a software reset of individual SoC devices.
Required Properties:
- compatible: Must be one of:
- "renesas,r8a7795-cpg-mssr" for the r8a7795 SoC (R-Car H3)
- "renesas,r8a7796-cpg-mssr" for the r8a7796 SoC (R-Car M3-W)
- reg: Base address and length of the memory resource used by the CPG/MSSR
block
- clocks: References to external parent clocks, one entry for each entry in
clock-names
- clock-names: List of external parent clock names. Valid names are:
- "extal" (r8a7795, r8a7796)
- "extalr" (r8a7795, r8a7796)
- #clock-cells: Must be 2
- For CPG core clocks, the two clock specifier cells must be "CPG_CORE"
and a core clock reference, as defined in
<dt-bindings/clock/*-cpg-mssr.h>.
- For module clocks, the two clock specifier cells must be "CPG_MOD" and
a module number, as defined in the datasheet.
- #power-domain-cells: Must be 0
- SoC devices that are part of the CPG/MSSR Clock Domain and can be
power-managed through Module Standby should refer to the CPG device
node in their "power-domains" property, as documented by the generic PM
Domain bindings in
Documentation/devicetree/bindings/power/power_domain.txt.
Examples
--------
- CPG device node:
cpg: clock-controller@e6150000 {
compatible = "renesas,r8a7795-cpg-mssr";
reg = <0 0xe6150000 0 0x1000>;
clocks = <&extal_clk>, <&extalr_clk>;
clock-names = "extal", "extalr";
#clock-cells = <2>;
#power-domain-cells = <0>;
};
- CPG/MSSR Clock Domain member device node:
scif2: serial@e6e88000 {
compatible = "renesas,scif-r8a7795", "renesas,scif";
reg = <0 0xe6e88000 0 64>;
interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&cpg CPG_MOD 310>;
clock-names = "fck";
dmas = <&dmac1 0x13>, <&dmac1 0x12>;
dma-names = "tx", "rx";
power-domains = <&cpg>;
status = "disabled";
};