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+DT bindings for the Renesas R-Car System Controller
+
+== System Controller Node ==
+
+The R-Car System Controller provides power management for the CPU cores and
+various coprocessors.
+
+Required properties:
+ - compatible: Should be "renesas,sysc-<soctype>", "renesas,sysc-rcar" as
+ fallback.
+ Examples with soctypes are:
+ - "renesas,sysc-r8a7779" (R-Car H1)
+ - "renesas,sysc-r8a7790" (R-Car H2)
+ - "renesas,sysc-r8a7791" (R-Car M2-W)
+ - "renesas,sysc-r8a7793" (R-Car M2-N)
+ - "renesas,sysc-r8a7794" (R-Car E2)
+ - reg: Address start and address range for the device.
+ - pm-domains: This node contains a hierarchy of PM Domain Nodes.
+ Dependencies (e.g. parent SCUs should not be powered off while child CPUs
+ are on) should be reflected using subnodes.
+
+
+== PM Domain Nodes ==
+
+Each of the PM domain nodes represents a PM domain, as documented by the
+generic PM domain bindings in
+Documentation/devicetree/bindings/power/power_domain.txt.
+
+Required properties:
+ - #power-domain-cells: Must be 0.
+ - reg: This property must contain 2 values:
+ - The first value is the number of the interrupt bit representing
+ the power area in the various Interrupt Registers (e.g. SYSCISR,
+ Interrupt Status Register),
+ - The second value encodes the power register block offset (which is
+ a multiple of 64), and the number of the bit representing the
+ power area in the various Power Control Registers (e.g. PWROFFSR,
+ Power Shutoff Status Register). This value is created by ORing
+ these two numbers.
+ The parent's node must contain the following two properties:
+ - #address-cells: Must be 2,
+ - #size-cells: Must be 0.
+
+
+Example:
+
+ sysc: system-controller@e6180000 {
+ compatible = "renesas,sysc-r8a7791", "renesas,sysc-rcar";
+ reg = <0 0xe6180000 0 0x0200>;
+
+ pm-domains {
+ #address-cells = <2>;
+ #size-cells = <0>;
+
+ pd_ca15_scu: scu@12 {
+ reg = <12 0x180>;
+ #address-cells = <2>;
+ #size-cells = <0>;
+ #power-domain-cells = <0>;
+
+ pd_ca15_cpu0: cpu@0 {
+ reg = <0 0x40>;
+ #power-domain-cells = <0>;
+ };
+
+ pd_ca15_cpu1: cpu@1 {
+ reg = <1 0x41>;
+ #power-domain-cells = <0>;
+ };
+ };
+
+ pd_sh: sh@16 {
+ reg = <16 0x80>;
+ #power-domain-cells = <0>;
+ };
+
+ pd_sgx: sgx@20 {
+ reg = <20 0xc0>;
+ #power-domain-cells = <0>;
+ };
+ };
+ };
The Renesas R-Car System Controller provides power management for the CPU cores and various coprocessors, following the generic PM domain bindings in Documentation/devicetree/bindings/power/power_domain.txt. This supports both R-Car Gen1 and Gen2. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- Alternatives I considered: - Using a single node per power register block, even if it contains multiple domains. - You cannot just have a property with the number of domains, as index 0 is not used on R-Car H1. Hence the need for "renesas,pm-domain-indices" and "renesas,interrupt-bits", - "#power-domain-cells = <1>" for nodes with multiple domains, which allows typos in "power-domains = <&pd_ca15_cpu n>", using an invalid value of "n", - Hence my first version had: pd_ca15_scu: ca15_scu@180 { reg = <0x180 0x20>; #address-cells = <1>; #size-cells = <0>; #power-domain-cells = <0>; renesas,interrupt-bits = <12>; pd_ca15_cpu: ca15_cpu@40 { reg = <0x40 0x20>; #power-domain-cells = <1>; renesas,pm-domain-indices = <0 1>; renesas,pm-domain-names = "ca15_cpu0", "ca15_cpu1"; renesas,interrupt-bits = <0 1>; }; }; - Using a linear description in DT - Needs parent links for subdomains, - More complicated to parse (lesson learned from R-Mobile PM Domain support). - Keeping the power register block offset and the bit number as separate "reg" cells, increasing "#address-cells" from 2 to 3, - Merging the interrupt bit (which needs only 5 bits) in the other "reg" cell, decreasing "#address-cells" from 2 to 1. .../bindings/power/renesas,sysc-rcar.txt | 82 ++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 Documentation/devicetree/bindings/power/renesas,sysc-rcar.txt