linux-kernel - Re: [PATCH v2 1/3] dt-bindings: regulator: Document regulators coupling of NVIDIA Tegra20/30 SoCs

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Message-ID: <ae79a9c0-7c87-63e4-8555-b80851cb22cd@gmail.com>
Date:   Fri, 2 Aug 2019 17:47:22 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Rob Herring <robh+dt@...nel.org>,
        Thierry Reding <thierry.reding@...il.com>,
        Peter De Schrijver <pdeschrijver@...dia.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Mark Brown <broonie@...nel.org>
Cc:     devicetree@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/3] dt-bindings: regulator: Document regulators
 coupling of NVIDIA Tegra20/30 SoCs

25.07.2019 18:18, Dmitry Osipenko пишет:
> There is voltage coupling between three regulators on Tegra20 boards and
> between two on Tegra30. The voltage coupling is a SoC-level feature and
> thus it is mandatory and common for all of the Tegra boards.
> 
> Signed-off-by: Dmitry Osipenko <digetx@...il.com>
> ---
>  .../nvidia,tegra-regulators-coupling.txt      | 65 +++++++++++++++++++
>  1 file changed, 65 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/regulator/nvidia,tegra-regulators-coupling.txt
> 
> diff --git a/Documentation/devicetree/bindings/regulator/nvidia,tegra-regulators-coupling.txt b/Documentation/devicetree/bindings/regulator/nvidia,tegra-regulators-coupling.txt
> new file mode 100644
> index 000000000000..4bf2dbf7c6cc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/regulator/nvidia,tegra-regulators-coupling.txt
> @@ -0,0 +1,65 @@
> +NVIDIA Tegra Regulators Coupling
> +================================
> +
> +NVIDIA Tegra SoC's have a mandatory voltage-coupling between regulators.
> +Thus on Tegra20 there are 3 coupled regulators and on NVIDIA Tegra30
> +there are 2.
> +
> +Tegra20 voltage coupling
> +------------------------
> +
> +On Tegra20 SoC's there are 3 coupled regulators: CORE, RTC and CPU.
> +The CORE and RTC voltages shall be in a range of 170mV from each other
> +and they both shall be higher than the CPU voltage by at least 120mV.
> +
> +Tegra30 voltage coupling
> +------------------------
> +
> +On Tegra30 SoC's there are 2 coupled regulators: CORE and CPU. The CORE
> +and CPU voltages shall be in a range of 300mV from each other and CORE
> +voltage shall be higher than the CPU by N mV, where N depends on the CPU
> +voltage.
> +
> +Required properties:
> +- nvidia,tegra-core-regulator: Boolean property that designates regulator
> +  as the "Core domain" voltage regulator.
> +- nvidia,tegra-rtc-regulator: Boolean property that designates regulator
> +  as the "RTC domain" voltage regulator.
> +- nvidia,tegra-cpu-regulator: Boolean property that designates regulator
> +  as the "CPU domain" voltage regulator.
> +
> +Example:
> +
> +	pmic {
> +		regulators {
> +			core_vdd_reg: core {
> +				regulator-name = "vdd_core";
> +				regulator-min-microvolt = <950000>;
> +				regulator-max-microvolt = <1300000>;
> +				regulator-coupled-with = <&rtc_vdd_reg &cpu_vdd_reg>;
> +				regulator-coupled-max-spread = <170000 550000>;
> +
> +				nvidia,tegra-core-regulator;
> +			};
> +
> +			rtc_vdd_reg: rtc {
> +				regulator-name = "vdd_rtc";
> +				regulator-min-microvolt = <950000>;
> +				regulator-max-microvolt = <1300000>;
> +				regulator-coupled-with = <&core_vdd_reg &cpu_vdd_reg>;
> +				regulator-coupled-max-spread = <170000 550000>;
> +
> +				nvidia,tegra-rtc-regulator;
> +			};
> +
> +			cpu_vdd_reg: cpu {
> +				regulator-name = "vdd_cpu";
> +				regulator-min-microvolt = <750000>;
> +				regulator-max-microvolt = <1125000>;
> +				regulator-coupled-with = <&core_vdd_reg &rtc_vdd_reg>;
> +				regulator-coupled-max-spread = <550000 550000>;
> +
> +				nvidia,tegra-cpu-regulator;
> +			};
> +		};
> +	};
> 

Hello Rob,

Are you okay with this patch? We just need to mark the SoC voltage
regulators appropriately and regulators themselves vary from board to
board, hence this binding is not something that could be done using
YAML, I guess.