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From:   Alistair Francis <alistair23@gmail.com>
Date:   Fri, 20 Jan 2023 19:17:00 +1000
Message-ID: <CAKmqyKMvSYr6WiVrvQWCWeiYF3R-VJmfuwxXczyE9j4QnYB_KA@mail.gmail.com>
Subject: Re: [PATCH v2 3/3] ARM: dts: imx7d-remarkable2: Enable the rohm,bd71815
To:     Matti Vaittinen <mazziesaccount@gmail.com>
Cc:     Marco Felsch <m.felsch@pengutronix.de>,
        Alistair Francis <alistair@alistair23.me>,
        linux-kernel@vger.kernel.org, shawnguo@kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-imx@nxp.com,
        s.hauer@pengutronix.de, robh+dt@kernel.org,
        devicetree@vger.kernel.org, krzysztof.kozlowski+dt@linaro.org,
        arnd@arndb.de, linux@armlinux.org.uk, jernej.skrabec@gmail.com,
        kernel@pengutronix.de, festevam@gmail.com
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On Tue, Jan 10, 2023 at 5:13 AM Matti Vaittinen
<mazziesaccount@gmail.com> wrote:
>
> ma 9. tammik. 2023 klo 14.32 Alistair Francis (alistair23@gmail.com) kirjoitti:
> >
> > On Tue, Dec 20, 2022 at 11:17 PM Marco Felsch <m.felsch@pengutronix.de> wrote:
> > >
> > > Hi Alistair,
> > >
> > > thanks for your patch, please see below.
> > >
> > > On 22-12-20, Alistair Francis wrote:
> > > > Add support for the rohm,bd71815 power controller controller for the
> > > > reMarkable 2.
> > > >
> > > > Signed-off-by: Alistair Francis <alistair@alistair23.me>
> > > > ---
> > > >  arch/arm/boot/dts/imx7d-remarkable2.dts | 159 ++++++++++++++++++++++++
> > > >  1 file changed, 159 insertions(+)
> > > >
> > > > diff --git a/arch/arm/boot/dts/imx7d-remarkable2.dts b/arch/arm/boot/dts/imx7d-remarkable2.dts
> > > > index a138b292ec6a..4387d30d6180 100644
> > > > --- a/arch/arm/boot/dts/imx7d-remarkable2.dts
> > > > +++ b/arch/arm/boot/dts/imx7d-remarkable2.dts
> > > > @@ -92,6 +92,10 @@ wifi_pwrseq: wifi_pwrseq {
> > > >       };
> > > >  };
> > > >
> > > > +&cpu0 {
> > > > +     cpu-supply = <&buck1_reg>;
> > > > +};
> > > > +
> > > >  &clks {
> > > >       assigned-clocks = <&clks IMX7D_CLKO2_ROOT_SRC>,
> > > >                         <&clks IMX7D_CLKO2_ROOT_DIV>;
> > > > @@ -119,6 +123,148 @@ wacom_digitizer: digitizer@9 {
> > > >       };
> > > >  };
> > > >
> > > > +&i2c2 {
> > > > +     clock-frequency = <100000>;
> > >
> > > We can set this now to 400kHz since the driver can handle quirks now
> > > internal.
> >
> > After a discussion on the first patch I'm going to leave this as is.
> > Let me know if you do want me to change it.
> >
> > >
> > > > +     pinctrl-names = "default", "sleep";
> > > > +     pinctrl-0 = <&pinctrl_i2c2>;
> > > > +     pinctrl-1 = <&pinctrl_i2c2>;
> > >
> > > Do we need a "sleep" config here since this will be the same
> > > configuration as the "default" one.
> >
> > Nope, dropped.
> >
> > >
> > > > +     status = "okay";
> > > > +
> > > > +     bd71815: pmic@4b {
> > > > +             compatible = "rohm,bd71815";
> > > > +             reg = <0x4b>;
> > > > +             pinctrl-names = "default";
> > > > +             pinctrl-0 = <&pinctrl_bd71815>;
> > > > +             interrupt-parent = <&gpio6>; /* PMIC_INT_B GPIO6_IO16 */
> > > > +             interrupts = <16 IRQ_TYPE_LEVEL_LOW>;
> > > > +             gpio-controller;
> > > > +             clocks = <&clks IMX7D_CLKO2_ROOT_SRC>;
> > > > +             clock-output-names = "bd71815-32k-out";
> > > > +             #clock-cells = <0>;
> > > > +             #gpio-cells = <1>;
> > > > +
> > > > +             regulators {
> > > > +                     #address-cells = <1>;
> > > > +                     #size-cells = <0>;
> > > > +
> > > > +                     buck1_reg: regulator@0 {
> > > > +                             reg = <0>;
> > > > +                             regulator-compatible = "buck1";
> > > > +                             regulator-min-microvolt = <800000>;
> > > > +                             regulator-max-microvolt = <2000000>;
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                             regulator-ramp-delay = <1250>;
> > > > +                     };
> > > > +
> > > > +                     buck2_reg: regulator@1 {
> > > > +                             reg = <1>;
> > > > +                             regulator-compatible = "buck2";
> > > > +                             regulator-min-microvolt = <800000>;
> > > > +                             regulator-max-microvolt = <2000000>;
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                             regulator-ramp-delay = <1250>;
> > > > +                     };
> > > > +
> > > > +                     buck3_reg: regulator@2 {
> > > > +                             reg = <2>;
> > > > +                             regulator-compatible = "buck3";
> > > > +                             regulator-min-microvolt = <1200000>;
> > > > +                             regulator-max-microvolt = <2700000>;
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                     };
> > > > +
> > > > +                     buck4_reg: regulator@3 {
> > > > +                             reg = <3>;
> > > > +                             regulator-compatible = "buck4";
> > > > +                             regulator-min-microvolt = <1100000>;
> > > > +                             regulator-max-microvolt = <1850000>;
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                     };
> > > > +
> > > > +                     buck5_reg: regulator@4 {
> > > > +                             reg = <4>;
> > > > +                             regulator-compatible = "buck5";
> > > > +                             regulator-min-microvolt = <1800000>;
> > > > +                             regulator-max-microvolt = <3300000>;
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                     };
> > > > +
> > > > +                     ldo1_reg: regulator@5 {
> > > > +                             reg = <5>;
> > > > +                             regulator-compatible = "ldo1";
> > > > +                             regulator-min-microvolt = <800000>;
> > > > +                             regulator-max-microvolt = <3300000>;
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                     };
> > > > +
> > > > +                     ldo2_reg: regulator@6 {
> > > > +                             reg = <6>;
> > > > +                             regulator-compatible = "ldo2";
> > > > +                             regulator-min-microvolt = <800000>;
> > > > +                             regulator-max-microvolt = <3300000>;
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                     };
> > > > +
> > > > +                     ldo3_reg: regulator@7 {
> > > > +                             reg = <7>;
> > > > +                             regulator-compatible = "ldo3";
> > > > +                             regulator-min-microvolt = <800000>;
> > > > +                             regulator-max-microvolt = <3300000>;
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                     };
> > > > +
> > > > +                     ldo4_reg: regulator@8 {
> > > > +                             reg = <8>;
> > > > +                             regulator-compatible = "ldo4";
> > > > +                             regulator-min-microvolt = <800000>;
> > > > +                             regulator-max-microvolt = <3300000>;
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                     };
> > > > +
> > > > +                     ldo5_reg: regulator@9 {
> > > > +                             reg = <9>;
> > > > +                             regulator-compatible = "ldo5";
> > > > +                             regulator-min-microvolt = <800000>;
> > > > +                             regulator-max-microvolt = <3300000>;
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                     };
> > > > +
> > > > +                     dvref_reg: regulator@a {
> > > > +                             reg = <0xa>;
> > > > +                             regulator-compatible = "dvref";
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                     };
> > > > +
> > > > +                     lpsr_reg: regulator@b {
> > > > +                             reg = <0xb>;
> > > > +                             regulator-compatible = "lpsr";
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                     };
> > > > +
> > > > +                     wled_reg: regulator@c {
> > > > +                             reg = <0xc>;
> > > > +                             regulator-compatible = "wled";
> > > > +                             regulator-min-microamp = <10>;
> > > > +                             regulator-max-microamp = <25000>;
> > > > +                             regulator-boot-on;
> > > > +                             regulator-always-on;
> > > > +                     };
> > >
> > > Note: You have marked all regulators as always on, this is rather
> > > suboptimal due to power consumption.
> >
> > Good point. The power consumption is already pretty bad, as mainline
> > doesn't support the i.MX deep sleep. As I know this works I'd like to
> > keep it as is. I'll test to see if removing them doesn't break
> > anything and then send a follow up patch.
>
> I'd like to suggest also seeing what removing the "regulator-boot-on"
> causes. As far as I understand, the "regulator-boot-on" mainly (only?)
> intended to be used in situations where the regulator state can not be
> reliably read from the hardware at the boot-up. AFAIR, unlike the
> BD71837 and BD71847,
> the BD71815 does not have this limitation. (This is just my
> understanding - which is based on some age-old discussions with Mark
> Brown - hence this comment is just a suggestion to try this while
> testing, not a comment intended to be demanding for a change)

I have tried removing both "regulator-boot-on" and "regulator-always-on".

After one boot to userspace (where the display didn't work correctly)
the device now seems to not power up at all. Even u-boot is failing to
start. I'm not sure if the regulators are now in some strange state or
if something is fried.

I'm currently waiting for the battery to discharge to see if that helps.

Alistair

>
> Yours
>     Matti
>
> --
>
> Matti Vaittinen
> Linux kernel developer at ROHM Semiconductors
> Oulu Finland
>
> ~~ When things go utterly wrong vim users can always type :help! ~~
>
> Discuss - Estimate - Plan - Report and finally accomplish this:
> void do_work(int time) __attribute__ ((const));