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Diffstat (limited to 'Documentation/devicetree/bindings/opp/sun50i-nvmem-cpufreq.txt')
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diff --git a/Documentation/devicetree/bindings/opp/sun50i-nvmem-cpufreq.txt b/Documentation/devicetree/bindings/opp/sun50i-nvmem-cpufreq.txt new file mode 100644 index 000000000000..7deae57a587b --- /dev/null +++ b/Documentation/devicetree/bindings/opp/sun50i-nvmem-cpufreq.txt @@ -0,0 +1,167 @@ +Allwinner Technologies, Inc. NVMEM CPUFreq and OPP bindings +=================================== + +For some SoCs, the CPU frequency subset and voltage value of each OPP +varies based on the silicon variant in use. Allwinner Process Voltage +Scaling Tables defines the voltage and frequency value based on the +speedbin blown in the efuse combination. The sun50i-cpufreq-nvmem driver +reads the efuse value from the SoC to provide the OPP framework with +required information. + +Required properties: +-------------------- +In 'cpus' nodes: +- operating-points-v2: Phandle to the operating-points-v2 table to use. + +In 'operating-points-v2' table: +- compatible: Should be + - 'allwinner,sun50i-h6-operating-points'. +- nvmem-cells: A phandle pointing to a nvmem-cells node representing the + efuse registers that has information about the speedbin + that is used to select the right frequency/voltage value + pair. Please refer the for nvmem-cells bindings + Documentation/devicetree/bindings/nvmem/nvmem.txt and + also examples below. + +In every OPP node: +- opp-microvolt-<name>: Voltage in micro Volts. + At runtime, the platform can pick a <name> and + matching opp-microvolt-<name> property. + [See: opp.txt] + HW: <name>: + sun50i-h6 speed0 speed1 speed2 + +Example 1: +--------- + + cpus { + #address-cells = <1>; + #size-cells = <0>; + + cpu0: cpu@0 { + compatible = "arm,cortex-a53"; + device_type = "cpu"; + reg = <0>; + enable-method = "psci"; + clocks = <&ccu CLK_CPUX>; + clock-latency-ns = <244144>; /* 8 32k periods */ + operating-points-v2 = <&cpu_opp_table>; + #cooling-cells = <2>; + }; + + cpu1: cpu@1 { + compatible = "arm,cortex-a53"; + device_type = "cpu"; + reg = <1>; + enable-method = "psci"; + clocks = <&ccu CLK_CPUX>; + clock-latency-ns = <244144>; /* 8 32k periods */ + operating-points-v2 = <&cpu_opp_table>; + #cooling-cells = <2>; + }; + + cpu2: cpu@2 { + compatible = "arm,cortex-a53"; + device_type = "cpu"; + reg = <2>; + enable-method = "psci"; + clocks = <&ccu CLK_CPUX>; + clock-latency-ns = <244144>; /* 8 32k periods */ + operating-points-v2 = <&cpu_opp_table>; + #cooling-cells = <2>; + }; + + cpu3: cpu@3 { + compatible = "arm,cortex-a53"; + device_type = "cpu"; + reg = <3>; + enable-method = "psci"; + clocks = <&ccu CLK_CPUX>; + clock-latency-ns = <244144>; /* 8 32k periods */ + operating-points-v2 = <&cpu_opp_table>; + #cooling-cells = <2>; + }; + }; + + cpu_opp_table: opp_table { + compatible = "allwinner,sun50i-h6-operating-points"; + nvmem-cells = <&speedbin_efuse>; + opp-shared; + + opp@480000000 { + clock-latency-ns = <244144>; /* 8 32k periods */ + opp-hz = /bits/ 64 <480000000>; + + opp-microvolt-speed0 = <880000>; + opp-microvolt-speed1 = <820000>; + opp-microvolt-speed2 = <800000>; + }; + + opp@720000000 { + clock-latency-ns = <244144>; /* 8 32k periods */ + opp-hz = /bits/ 64 <720000000>; + + opp-microvolt-speed0 = <880000>; + opp-microvolt-speed1 = <820000>; + opp-microvolt-speed2 = <800000>; + }; + + opp@816000000 { + clock-latency-ns = <244144>; /* 8 32k periods */ + opp-hz = /bits/ 64 <816000000>; + + opp-microvolt-speed0 = <880000>; + opp-microvolt-speed1 = <820000>; + opp-microvolt-speed2 = <800000>; + }; + + opp@888000000 { + clock-latency-ns = <244144>; /* 8 32k periods */ + opp-hz = /bits/ 64 <888000000>; + + opp-microvolt-speed0 = <940000>; + opp-microvolt-speed1 = <820000>; + opp-microvolt-speed2 = <800000>; + }; + + opp@1080000000 { + clock-latency-ns = <244144>; /* 8 32k periods */ + opp-hz = /bits/ 64 <1080000000>; + + opp-microvolt-speed0 = <1060000>; + opp-microvolt-speed1 = <880000>; + opp-microvolt-speed2 = <840000>; + }; + + opp@1320000000 { + clock-latency-ns = <244144>; /* 8 32k periods */ + opp-hz = /bits/ 64 <1320000000>; + + opp-microvolt-speed0 = <1160000>; + opp-microvolt-speed1 = <940000>; + opp-microvolt-speed2 = <900000>; + }; + + opp@1488000000 { + clock-latency-ns = <244144>; /* 8 32k periods */ + opp-hz = /bits/ 64 <1488000000>; + + opp-microvolt-speed0 = <1160000>; + opp-microvolt-speed1 = <1000000>; + opp-microvolt-speed2 = <960000>; + }; + }; +.... +soc { +.... + sid: sid@3006000 { + compatible = "allwinner,sun50i-h6-sid"; + reg = <0x03006000 0x400>; + #address-cells = <1>; + #size-cells = <1>; + .... + speedbin_efuse: speed@1c { + reg = <0x1c 4>; + }; + }; +}; |