linux-kernel - Re: [PATCH V2 03/15] arm64: dts: imx8mp-evk: fix BUCK/LDO voltage

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Message-ID: <20221028145306.66lcoycuzmfb5yug@pengutronix.de>
Date:   Fri, 28 Oct 2022 16:53:06 +0200
From:   Marco Felsch <m.felsch@...gutronix.de>
To:     "Peng Fan (OSS)" <peng.fan@....nxp.com>
Cc:     robh+dt@...nel.org, krzysztof.kozlowski+dt@...aro.org,
        shawnguo@...nel.org, s.hauer@...gutronix.de,
        devicetree@...r.kernel.org, Peng Fan <peng.fan@....com>,
        linux-kernel@...r.kernel.org, linux-imx@....com,
        kernel@...gutronix.de, festevam@...il.com,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH V2 03/15] arm64: dts: imx8mp-evk: fix BUCK/LDO voltage

On 22-10-24, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@....com>
> 
> Per PCA9450C datasheet, the voltage range as below:
> BUCK1 0.6 - 2.1875
> BUCK2 0.6 - 2.1875
> BUCK4 0.6 - 3.4
> BUCK5 0.6 - 3.4
> BUCK6 0.6 - 3.4
> 
> LDO1 1.6-1.9, 3.0-3.3
> LDO2 0.8 – 1.15
> LDO3 0.8 - 3.3
> LDO4 0.8 - 3.3
> LDO5 1.8 - 3.3
> 
> Currently we set the board voltage range same as PMIC regulator
> range.

We did not therefore you aligned it. Also are you sure that this will
not damage the boards since you're lowering the min-voltage and raising
the max. voltage? According the schematic, BUCK1 is for VDD_SOC which is
min. 0.805V and max. 1.0V. After you're change someone could set it to
2.1875V. Same applies to BUCK2 which is for VDD_ARM and should be within
min. 0.805V and max. 1.05V.

Regards,
  Marco

> Also add LDO[2,4] in this patch
> 
> Fixes: 5497bc2a2bff ("arm64: dts: imx8mp-evk: Add PMIC device")
> Signed-off-by: Peng Fan <peng.fan@....com>
> ---
>  arch/arm64/boot/dts/freescale/imx8mp-evk.dts | 44 +++++++++++++-------
>  1 file changed, 30 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
> index b4c1ef2559f2..a4cddc5a8620 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
> @@ -248,8 +248,8 @@ pmic@25 {
>  		regulators {
>  			BUCK1 {
>  				regulator-name = "BUCK1";
> -				regulator-min-microvolt = <720000>;
> -				regulator-max-microvolt = <1000000>;
> +				regulator-min-microvolt = <600000>;
> +				regulator-max-microvolt = <2187500>;
>  				regulator-boot-on;
>  				regulator-always-on;
>  				regulator-ramp-delay = <3125>;
> @@ -257,8 +257,8 @@ BUCK1 {
>  
>  			reg_arm: BUCK2 {
>  				regulator-name = "BUCK2";
> -				regulator-min-microvolt = <720000>;
> -				regulator-max-microvolt = <1025000>;
> +				regulator-min-microvolt = <600000>;
> +				regulator-max-microvolt = <2187500>;
>  				regulator-boot-on;
>  				regulator-always-on;
>  				regulator-ramp-delay = <3125>;
> @@ -268,40 +268,56 @@ reg_arm: BUCK2 {
>  
>  			BUCK4 {
>  				regulator-name = "BUCK4";
> -				regulator-min-microvolt = <3000000>;
> -				regulator-max-microvolt = <3600000>;
> +				regulator-min-microvolt = <600000>;
> +				regulator-max-microvolt = <3400000>;
>  				regulator-boot-on;
>  				regulator-always-on;
>  			};
>  
>  			BUCK5 {
>  				regulator-name = "BUCK5";
> -				regulator-min-microvolt = <1650000>;
> -				regulator-max-microvolt = <1950000>;
> +				regulator-min-microvolt = <600000>;
> +				regulator-max-microvolt = <3400000>;
>  				regulator-boot-on;
>  				regulator-always-on;
>  			};
>  
>  			BUCK6 {
>  				regulator-name = "BUCK6";
> -				regulator-min-microvolt = <1045000>;
> -				regulator-max-microvolt = <1155000>;
> +				regulator-min-microvolt = <600000>;
> +				regulator-max-microvolt = <3400000>;
>  				regulator-boot-on;
>  				regulator-always-on;
>  			};
>  
>  			LDO1 {
>  				regulator-name = "LDO1";
> -				regulator-min-microvolt = <1650000>;
> -				regulator-max-microvolt = <1950000>;
> +				regulator-min-microvolt = <1600000>;
> +				regulator-max-microvolt = <3300000>;
> +				regulator-boot-on;
> +				regulator-always-on;
> +			};
> +
> +			LDO2 {
> +				regulator-name = "LDO2";
> +				regulator-min-microvolt = <800000>;
> +				regulator-max-microvolt = <1150000>;
>  				regulator-boot-on;
>  				regulator-always-on;
>  			};
>  
>  			LDO3 {
>  				regulator-name = "LDO3";
> -				regulator-min-microvolt = <1710000>;
> -				regulator-max-microvolt = <1890000>;
> +				regulator-min-microvolt = <800000>;
> +				regulator-max-microvolt = <3300000>;
> +				regulator-boot-on;
> +				regulator-always-on;
> +			};
> +
> +			ldo4: LDO4 {
> +				regulator-name = "LDO4";
> +				regulator-min-microvolt = <800000>;
> +				regulator-max-microvolt = <3300000>;
>  				regulator-boot-on;
>  				regulator-always-on;
>  			};
> -- 
> 2.37.1
> 
> 
>