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    SubjectRe: [PATCH v2 06/11] arm64: dts: meson-g12a-x96-max: add regulators
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    On 18/03/2019 21:13, Martin Blumenstingl wrote:
    > Hi Neil,
    >
    > On Mon, Mar 18, 2019 at 11:06 AM Neil Armstrong <narmstrong@baylibre.com> wrote:
    >>
    >> From: Guillaume La Roque <glaroque@baylibre.com>
    >>
    >> Add system regulators for the X96 Max Set-Top-Box.
    >>
    >> Still missing
    >> * VDD_EE (0.8V - PWM controlled)
    >> * VDD_CPU (PWM controlled)
    >>
    >> Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
    >> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
    >> ---
    >> .../boot/dts/amlogic/meson-g12a-x96-max.dts | 67 +++++++++++++++++++
    >> 1 file changed, 67 insertions(+)
    >>
    >> diff --git a/arch/arm64/boot/dts/amlogic/meson-g12a-x96-max.dts b/arch/arm64/boot/dts/amlogic/meson-g12a-x96-max.dts
    >> index 0edbd00b358f..5c37930b09e2 100644
    >> --- a/arch/arm64/boot/dts/amlogic/meson-g12a-x96-max.dts
    >> +++ b/arch/arm64/boot/dts/amlogic/meson-g12a-x96-max.dts
    > [...]
    >> + vcc_5v: regulator-vcc_5v {
    >> + compatible = "regulator-fixed";
    >> + regulator-name = "VCC_5V";
    >> + regulator-min-microvolt = <5000000>;
    >> + regulator-max-microvolt = <5000000>;
    >> + vin-supply = <&dc_in>;
    >> +
    >> + gpio = <&gpio GPIOH_8 GPIO_OPEN_DRAIN>;
    >> + enable-active-high;
    > is there any way to test whether this GPIO is the right one?
    > I couldn't find a reference to a GPIOH_8 regulator in
    > buildroot_openlinux_kernel_4.9_fbdev_20180706

    The x96 is based on the U212 reference design, and the GPIOH_8 controls the 5V_EN signal,
    but you are right, it's the wrong polarity here, it should be enable-active-low instead.
    (FYI The SEI510 does not use this at all, 5V is always enabled)

    The schematics describes :
    VCC5V_EN (GPIOH_8-Hiz OD): 5V_EN
    L: Enable
    Hiz: Disable

    FYI, the GPIOH_8 is Open-Drain only, this means this pin cannot pull to TTL 1, only to TTL 0
    or set as input. We need to add a way to describe this in the pinctrl driver somehow....

    I will send a fix on v3

    I didn't notice because I power the board using a Type-A to Type-A connector,
    and the 5V from the USB port bypasses this regulator...

    Neil

    >
    >
    > Regards
    > Martin
    >

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