* [PATCH] arm64: dts: imx8mn-ddr4-evk: Adjust 1.2GHz OPP voltage to OD mode
@ 2020-02-18 1:52 Anson Huang
2020-02-24 1:48 ` Shawn Guo
0 siblings, 1 reply; 3+ messages in thread
From: Anson Huang @ 2020-02-18 1:52 UTC (permalink / raw)
To: robh+dt, mark.rutland, shawnguo, s.hauer, kernel, festevam,
abel.vesa, leonard.crestez, devicetree, linux-arm-kernel,
linux-kernel
Cc: Linux-imx
According to latest datasheet Rev.0, 10/2019, there is restriction
as below:
"If VDD_SOC/GPU/DDR = 0.95V, then VDD_ARM must be >= 0.95V."
As by default SoC is running at OD mode(VDD_SOC = 0.95V), so
VDD_ARM 1.2GHz OPP's voltage should be increased to 0.95V.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts b/arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts
index 2497eeb..7a61a1a 100644
--- a/arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts
@@ -13,6 +13,12 @@
compatible = "fsl,imx8mn-ddr4-evk", "fsl,imx8mn";
};
+&a53_opp_table {
+ opp-1200000000 {
+ opp-microvolt = <950000>;
+ };
+};
+
&A53_0 {
cpu-supply = <&buck2_reg>;
};
--
2.7.4
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^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] arm64: dts: imx8mn-ddr4-evk: Adjust 1.2GHz OPP voltage to OD mode
2020-02-18 1:52 [PATCH] arm64: dts: imx8mn-ddr4-evk: Adjust 1.2GHz OPP voltage to OD mode Anson Huang
@ 2020-02-24 1:48 ` Shawn Guo
2020-02-24 2:01 ` Anson Huang
0 siblings, 1 reply; 3+ messages in thread
From: Shawn Guo @ 2020-02-24 1:48 UTC (permalink / raw)
To: Anson Huang
Cc: mark.rutland, devicetree, abel.vesa, s.hauer, linux-kernel,
robh+dt, Linux-imx, kernel, leonard.crestez, festevam,
linux-arm-kernel
On Tue, Feb 18, 2020 at 09:52:32AM +0800, Anson Huang wrote:
> According to latest datasheet Rev.0, 10/2019, there is restriction
> as below:
>
> "If VDD_SOC/GPU/DDR = 0.95V, then VDD_ARM must be >= 0.95V."
>
> As by default SoC is running at OD mode(VDD_SOC = 0.95V), so
> VDD_ARM 1.2GHz OPP's voltage should be increased to 0.95V.
>
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> ---
> arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts b/arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts
> index 2497eeb..7a61a1a 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts
> @@ -13,6 +13,12 @@
> compatible = "fsl,imx8mn-ddr4-evk", "fsl,imx8mn";
> };
>
> +&a53_opp_table {
> + opp-1200000000 {
> + opp-microvolt = <950000>;
> + };
> +};
> +
The restriction applies to SoC rather than a particular board, right?
If so, the change should be made in imx8mn.dtsi?
Shawn
> &A53_0 {
> cpu-supply = <&buck2_reg>;
> };
> --
> 2.7.4
>
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^ permalink raw reply [flat|nested] 3+ messages in thread* RE: [PATCH] arm64: dts: imx8mn-ddr4-evk: Adjust 1.2GHz OPP voltage to OD mode
2020-02-24 1:48 ` Shawn Guo
@ 2020-02-24 2:01 ` Anson Huang
0 siblings, 0 replies; 3+ messages in thread
From: Anson Huang @ 2020-02-24 2:01 UTC (permalink / raw)
To: Shawn Guo
Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, Abel Vesa,
s.hauer@pengutronix.de, linux-kernel@vger.kernel.org,
robh+dt@kernel.org, dl-linux-imx, kernel@pengutronix.de,
Leonard Crestez, festevam@gmail.com,
linux-arm-kernel@lists.infradead.org
Hi, Shawn
> Subject: Re: [PATCH] arm64: dts: imx8mn-ddr4-evk: Adjust 1.2GHz OPP
> voltage to OD mode
>
> On Tue, Feb 18, 2020 at 09:52:32AM +0800, Anson Huang wrote:
> > According to latest datasheet Rev.0, 10/2019, there is restriction as
> > below:
> >
> > "If VDD_SOC/GPU/DDR = 0.95V, then VDD_ARM must be >= 0.95V."
> >
> > As by default SoC is running at OD mode(VDD_SOC = 0.95V), so VDD_ARM
> > 1.2GHz OPP's voltage should be increased to 0.95V.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > ---
> > arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts
> > b/arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts
> > index 2497eeb..7a61a1a 100644
> > --- a/arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts
> > +++ b/arch/arm64/boot/dts/freescale/imx8mn-ddr4-evk.dts
> > @@ -13,6 +13,12 @@
> > compatible = "fsl,imx8mn-ddr4-evk", "fsl,imx8mn"; };
> >
> > +&a53_opp_table {
> > + opp-1200000000 {
> > + opp-microvolt = <950000>;
> > + };
> > +};
> > +
>
> The restriction applies to SoC rather than a particular board, right?
> If so, the change should be made in imx8mn.dtsi?
Yes, you are correct, for now, it is NOT related to board, I will do the change
in .dtsi in V2.
Anson
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^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-02-18 1:52 [PATCH] arm64: dts: imx8mn-ddr4-evk: Adjust 1.2GHz OPP voltage to OD mode Anson Huang
2020-02-24 1:48 ` Shawn Guo
2020-02-24 2:01 ` Anson Huang
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