1NVIDIA Tegra Regulators Coupling 2================================ 3 4NVIDIA Tegra SoC's have a mandatory voltage-coupling between regulators. 5Thus on Tegra20 there are 3 coupled regulators and on NVIDIA Tegra30 6there are 2. 7 8Tegra20 voltage coupling 9------------------------ 10 11On Tegra20 SoC's there are 3 coupled regulators: CORE, RTC and CPU. 12The CORE and RTC voltages shall be in a range of 170mV from each other 13and they both shall be higher than the CPU voltage by at least 120mV. 14 15Tegra30 voltage coupling 16------------------------ 17 18On Tegra30 SoC's there are 2 coupled regulators: CORE and CPU. The CORE 19and CPU voltages shall be in a range of 300mV from each other and CORE 20voltage shall be higher than the CPU by N mV, where N depends on the CPU 21voltage. 22 23Required properties: 24- nvidia,tegra-core-regulator: Boolean property that designates regulator 25 as the "Core domain" voltage regulator. 26- nvidia,tegra-rtc-regulator: Boolean property that designates regulator 27 as the "RTC domain" voltage regulator. 28- nvidia,tegra-cpu-regulator: Boolean property that designates regulator 29 as the "CPU domain" voltage regulator. 30 31Example: 32 33 pmic { 34 regulators { 35 core_vdd_reg: core { 36 regulator-name = "vdd_core"; 37 regulator-min-microvolt = <950000>; 38 regulator-max-microvolt = <1300000>; 39 regulator-coupled-with = <&rtc_vdd_reg &cpu_vdd_reg>; 40 regulator-coupled-max-spread = <170000 550000>; 41 42 nvidia,tegra-core-regulator; 43 }; 44 45 rtc_vdd_reg: rtc { 46 regulator-name = "vdd_rtc"; 47 regulator-min-microvolt = <950000>; 48 regulator-max-microvolt = <1300000>; 49 regulator-coupled-with = <&core_vdd_reg &cpu_vdd_reg>; 50 regulator-coupled-max-spread = <170000 550000>; 51 52 nvidia,tegra-rtc-regulator; 53 }; 54 55 cpu_vdd_reg: cpu { 56 regulator-name = "vdd_cpu"; 57 regulator-min-microvolt = <750000>; 58 regulator-max-microvolt = <1125000>; 59 regulator-coupled-with = <&core_vdd_reg &rtc_vdd_reg>; 60 regulator-coupled-max-spread = <550000 550000>; 61 62 nvidia,tegra-cpu-regulator; 63 }; 64 }; 65 }; 66