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From:   Vicente Bergas <vicencb@gmail.com>
To:     Kever Yang <kever.yang@rock-chips.com>
Cc:     <heiko@sntech.de>, <linux-rockchip@lists.infradead.org>,
        Elaine Zhang <zhangqing@rock-chips.com>,
        Peter Robinson <pbrobinson@gmail.com>,
        Akash Gajjar <akash@openedev.com>,
        Alexis Ballier <aballier@gentoo.org>,
        =?utf-8?B?QW5kcml1cyDFoHRpa29uYXM=?= <andrius@stikonas.eu>,
        Andy Yan <andyshrk@gmail.com>,
        Ezequiel Garcia <ezequiel@collabora.com>,
        Hugh Cole-Baker <sigmaris@gmail.com>,
        Katsuhiro Suzuki <katsuhiro@katsuster.net>,
        Mark Rutland <mark.rutland@arm.com>,
        Nick Xie <nick@khadas.com>,
        Oskari Lemmela <oskari@lemmela.net>,
        Pragnesh Patel <Pragnesh_Patel@mentor.com>,
        Rob Herring <robh+dt@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Soeren Moch <smoch@web.de>,
        Vivek Unune <npcomplete13@gmail.com>,
        <devicetree@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 3/3] arm64: dts: rk3399: Add init voltage for =?iso-8859-1?Q?vdd=5Flog?=
Date:   Wed, 13 Nov 2019 18:50:57 +0100
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 <20191111005158.25070-3-kever.yang@rock-chips.com>
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On Monday, November 11, 2019 1:51:58 AM CET, Kever Yang wrote:
> Since there is no devfreq used for vdd_log, so the vdd_log(pwm regulator)
> will be 'enable' with the dts node at a default PWM state with high or low
> output. Both too high or too low for vdd_log is not good for the board,
> add init voltage for driver to make the regulator get into a know output.
>
> Note that this will be used by U-Boot for init voltage output, and this
> is very important for it may get system hang somewhere during system
> boot up with regulator enable and without this init value.

Hi, just for reference: doing the math based on the Sapphire board
schematic, the values for vdd_log are:
|------|-------|
| PWM  | Volts |
|------|-------|
| Hi-Z | 1.136 |
|   0% | 1.356 |
| 100% | .9167 |
|------|-------|
The datasheet states that the acceptable range for vdd_log is 0.8 .. 1.0
So, an option could be to configure GPIO1_C3 as output high and vdd_log
would be at the range's center.

Aside from math on paper, it has been tested. Setting GPIO1_C3 as output
high gives a vdd_log of 0.922 measured volts and the board, so far, works
fine.

Regards,
  Vicente.

> CC: Elaine Zhang <zhangqing@rock-chips.com>
> CC: Peter Robinson <pbrobinson@gmail.com>
> Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
> ---
>
>  arch/arm64/boot/dts/rockchip/rk3399-evb.dts          | 1 +
>  arch/arm64/boot/dts/rockchip/rk3399-firefly.dts      | 1 +
>  arch/arm64/boot/dts/rockchip/rk3399-hugsun-x99.dts   | 1 +
>  arch/arm64/boot/dts/rockchip/rk3399-khadas-edge.dtsi | 1 +
>  arch/arm64/boot/dts/rockchip/rk3399-leez-p710.dts    | 1 +
>  arch/arm64/boot/dts/rockchip/rk3399-orangepi.dts     | 1 +
>  arch/arm64/boot/dts/rockchip/rk3399-roc-pc.dts       | 1 +
>  arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dts    | 1 +
>  arch/arm64/boot/dts/rockchip/rk3399-sapphire.dtsi    | 1 +
>  9 files changed, 9 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-evb.dts=20
> b/arch/arm64/boot/dts/rockchip/rk3399-evb.dts
> index 77008dca45bc..fa241aeb11b0 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-evb.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-evb.dts
> @@ -65,6 +65,7 @@
>  =09=09regulator-name =3D "vdd_center";
>  =09=09regulator-min-microvolt =3D <800000>;
>  =09=09regulator-max-microvolt =3D <1400000>;
> +=09=09regulator-init-microvolt =3D <950000>;
>  =09=09regulator-always-on;
>  =09=09regulator-boot-on;
>  =09=09status =3D "okay";
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-firefly.dts=20
> b/arch/arm64/boot/dts/rockchip/rk3399-firefly.dts
> index 92de83dd4dbc..4e45269fcdff 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-firefly.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-firefly.dts
> @@ -208,6 +208,7 @@
>  =09=09regulator-boot-on;
>  =09=09regulator-min-microvolt =3D <430000>;
>  =09=09regulator-max-microvolt =3D <1400000>;
> +=09=09regulator-init-microvolt =3D <950000>;
>  =09=09vin-supply =3D <&vcc_sys>;
>  =09};
>  };
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-hugsun-x99.dts=20
> b/arch/arm64/boot/dts/rockchip/rk3399-hugsun-x99.dts
> index c133e8d64b2a..692f3154edc3 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-hugsun-x99.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-hugsun-x99.dts
> @@ -100,6 +100,7 @@
>  =09=09regulator-name =3D "vdd_log";
>  =09=09regulator-min-microvolt =3D <800000>;
>  =09=09regulator-max-microvolt =3D <1400000>;
> +=09=09regulator-init-microvolt =3D <950000>;
>  =09=09regulator-always-on;
>  =09=09regulator-boot-on;
>  =09};
> diff --git=20
> a/arch/arm64/boot/dts/rockchip/rk3399-khadas-edge.dtsi=20
> b/arch/arm64/boot/dts/rockchip/rk3399-khadas-edge.dtsi
> index 4944d78a0a1c..c2ac80d99301 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-khadas-edge.dtsi
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-khadas-edge.dtsi
> @@ -79,6 +79,7 @@
>  =09=09regulator-boot-on;
>  =09=09regulator-min-microvolt =3D <800000>;
>  =09=09regulator-max-microvolt =3D <1400000>;
> +=09=09regulator-init-microvolt =3D <950000>;
>  =09=09vin-supply =3D <&vsys_3v3>;
>  =09};
> =20
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-leez-p710.dts=20
> b/arch/arm64/boot/dts/rockchip/rk3399-leez-p710.dts
> index 73be38a53796..c32abcc4ddc1 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-leez-p710.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-leez-p710.dts
> @@ -101,6 +101,7 @@
>  =09=09regulator-boot-on;
>  =09=09regulator-min-microvolt =3D <800000>;
>  =09=09regulator-max-microvolt =3D <1400000>;
> +=09=09regulator-init-microvolt =3D <950000>;
>  =09=09vin-supply =3D <&vcc5v0_sys>;
>  =09};
>  };
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-orangepi.dts=20
> b/arch/arm64/boot/dts/rockchip/rk3399-orangepi.dts
> index 0541dfce924d..9d674c51f025 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-orangepi.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-orangepi.dts
> @@ -164,6 +164,7 @@
>  =09=09regulator-boot-on;
>  =09=09regulator-min-microvolt =3D <800000>;
>  =09=09regulator-max-microvolt =3D <1400000>;
> +=09=09regulator-init-microvolt =3D <950000>;
>  =09=09vin-supply =3D <&vcc_sys>;
>  =09};
>  };
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-roc-pc.dts=20
> b/arch/arm64/boot/dts/rockchip/rk3399-roc-pc.dts
> index 19f7732d728c..7d856ce1d156 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-roc-pc.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-roc-pc.dts
> @@ -129,6 +129,7 @@
>  =09=09regulator-boot-on;
>  =09=09regulator-min-microvolt =3D <800000>;
>  =09=09regulator-max-microvolt =3D <1400000>;
> +=09=09regulator-init-microvolt =3D <950000>;
>  =09=09vin-supply =3D <&vcc3v3_sys>;
>  =09};
>  };
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dts=20
> b/arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dts
> index e544deb61d28..8fbccbc8bf47 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dts
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dts
> @@ -174,6 +174,7 @@
>  =09=09regulator-boot-on;
>  =09=09regulator-min-microvolt =3D <800000>;
>  =09=09regulator-max-microvolt =3D <1700000>;
> +=09=09regulator-init-microvolt =3D <950000>;
>  =09=09vin-supply =3D <&vcc5v0_sys>;
>  =09};
>  };
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399-sapphire.dtsi=20
> b/arch/arm64/boot/dts/rockchip/rk3399-sapphire.dtsi
> index 1bc1579674e5..f8e2cb8c0624 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399-sapphire.dtsi
> +++ b/arch/arm64/boot/dts/rockchip/rk3399-sapphire.dtsi
> @@ -133,6 +133,7 @@
>  =09=09regulator-boot-on;
>  =09=09regulator-min-microvolt =3D <800000>;
>  =09=09regulator-max-microvolt =3D <1400000>;
> +=09=09regulator-init-microvolt =3D <950000>;
>  =09=09vin-supply =3D <&vcc_sys>;
>  =09};
>  };