linux-kernel - Re: [PATCH 1/2] dt-bindings: regulator: Add bindings for Richtek RT5190A PMIC

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CADiBU387CFZNGoxu1G_8P8a6oFE-QLMTiDDXKTc0rkOsgbi4bw@mail.gmail.com>
Date:   Mon, 7 Mar 2022 22:21:25 +0800
From:   ChiYuan Huang <u0084500@...il.com>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>
Cc:     Mark Brown <broonie@...nel.org>, Rob Herring <robh+dt@...nel.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        cy_huang <cy_huang@...htek.com>,
        lkml <linux-kernel@...r.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@...r.kernel.org>
Subject: Re: [PATCH 1/2] dt-bindings: regulator: Add bindings for Richtek
 RT5190A PMIC

HI, Krzysztof:

Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com> 於 2022年3月7日 週一 下午9:27寫道：
>
> On 07/03/2022 14:21, ChiYuan Huang wrote:
> > Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com> 於 2022年3月7日 週一 下午7:14寫道：
> >>
> >> On 07/03/2022 11:08, cy_huang wrote:
> >>> From: ChiYuan Huang <cy_huang@...htek.com>
> >>>
> >>> Add bindings for Richtek RT5190A PMIC.
> >>>
> >>> Signed-off-by: ChiYuan Huang <cy_huang@...htek.com>
> >>> ---
> >>>  .../regulator/richtek,rt5190a-regulator.yaml       | 138 +++++++++++++++++++++
> >>>  1 file changed, 138 insertions(+)
> >>>  create mode 100644 Documentation/devicetree/bindings/regulator/richtek,rt5190a-regulator.yaml
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/regulator/richtek,rt5190a-regulator.yaml b/Documentation/devicetree/bindings/regulator/richtek,rt5190a-regulator.yaml
> >>> new file mode 100644
> >>> index 00000000..b9f5836
> >>> --- /dev/null
> >>> +++ b/Documentation/devicetree/bindings/regulator/richtek,rt5190a-regulator.yaml
> >>> @@ -0,0 +1,138 @@
> >>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> >>> +%YAML 1.2
> >>> +---
> >>> +$id: http://devicetree.org/schemas/regulator/richtek,rt5190a-regulator.yaml#
> >>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> >>> +
> >>> +title: Richtek RT5190A PMIC Regulator
> >>> +
> >>> +maintainers:
> >>> +  - ChiYuan Huang <cy_huang@...htek.com>
> >>> +
> >>> +description: |
> >>> +  The RT5190A integrates 1 channel buck controller, 3 channels high efficiency
> >>> +  synchronous buck converters, 1 LDO, I2C control interface and peripherial
> >>> +  logical control.
> >>> +
> >>> +  It also supports mute AC OFF depop sound and quick setting storage while
> >>> +  input power is removed.
> >>> +
> >>> +properties:
> >>> +  compatible:
> >>> +    enum:
> >>> +      - richtek,rt5190a
> >>> +
> >>> +  reg:
> >>> +    maxItems: 1
> >>> +
> >>> +  interrupts:
> >>> +    maxItems: 1
> >>> +
> >>> +  vin2-supply:
> >>> +    description: phandle to buck2 input voltage.
> >>> +
> >>> +  vin3-supply:
> >>> +    description: phandle to buck3 input voltage.
> >>> +
> >>> +  vin4-supply:
> >>> +    description: phandle to buck4 input voltage.
> >>> +
> >>> +  vinldo-supply:
> >>> +    description: phandle to ldo input voltage
> >>> +
> >>> +  richtek,buck1-fixed-microvolt:
> >>> +    description: buck1 fixed voltage that depends on the external resistor.
> >>> +    $ref: "/schemas/types.yaml#/definitions/uint32"
> >>
> >> You should use standard bindings for it.
> >>
> > Sorry, I didn't get the point for the meaning 'standard binding'.
> > Do you mean to change 'richtek,buck1-fixed-microvolt' or 'uint32' definition?
> > This voltage depends on the external resistor selection. It's 'fixed'
> > by the application.
>
> I meant that you should not have dedicated binding to set regulator
> voltage, but use regulator-min/max-microvolt instead, within one
> regulator node. Just set min/max to same level and handle it in the
> driver. See for example:
> drivers/regulator/scmi-regulator.c
>
As I know, regulator-min/max-microvolt is used as the usage constraint.

But out buck1/buck4/ldo vout is defined by
Vout = VFb * (1 + R1/R2) where R1/R2 is chosen by the circuit design.

It seems not similar with the scmi-regulator.

Do you really suggest to use regulator-min/max-microvolt????

>
> Best regards,
> Krzysztof