linux-kernel - Re: [PATCH v3 1/3] dt-bindings: mmc: renesas,sdhi: Document RZ/V2H(P) support

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: <CA+V-a8uhb1Visg9jUV-Te3ZHkfdRonM08s823RYa6k=KAHYgQw@mail.gmail.com>
Date: Tue, 25 Jun 2024 09:46:54 +0100
From: "Lad, Prabhakar" <prabhakar.csengg@...il.com>
To: Geert Uytterhoeven <geert@...ux-m68k.org>
Cc: Ulf Hansson <ulf.hansson@...aro.org>, Wolfram Sang <wsa+renesas@...g-engineering.com>, 
	Geert Uytterhoeven <geert+renesas@...der.be>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Magnus Damm <magnus.damm@...il.com>, linux-mmc@...r.kernel.org, 
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, 
	linux-renesas-soc@...r.kernel.org, Biju Das <biju.das.jz@...renesas.com>, 
	Fabrizio Castro <fabrizio.castro.jz@...esas.com>, 
	Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
Subject: Re: [PATCH v3 1/3] dt-bindings: mmc: renesas,sdhi: Document RZ/V2H(P) support

Hi Geert,

Thank you for the review.

On Tue, Jun 25, 2024 at 7:57 AM Geert Uytterhoeven <geert@...ux-m68k.org> wrote:
>
> Hi Prabhakar,
>
> On Mon, Jun 24, 2024 at 5:33 PM Prabhakar <prabhakar.csengg@...il.com> wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
> >
> > The SD/MMC block on the RZ/V2H(P) ("R9A09G057") SoC is similar to that
> > of the R-Car Gen3, but it has some differences:
> > - HS400 is not supported.
> > - It supports the SD_IOVS bit to control the IO voltage level.
> > - It supports fixed address mode.
> >
> > To accommodate these differences, a SoC-specific 'renesas,sdhi-r9a09g057'
> > compatible string is added.
> >
> > A 'vqmmc-regulator' object is introduced to handle the power enable (PWEN)
> > and voltage level switching for the SD/MMC.
> >
> > Additionally, the 'renesas,sdhi-use-internal-regulator' flag is introduced
> > to indicate that an internal regulator is used instead of a
> > GPIO-controlled regulator. This flag will help configure the internal
> > regulator and avoid special handling when GPIO is used for voltage
> > regulation instead of the SD_(IOVS/PWEN) pins.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
> > ---
> > v2->v3
> > - Renamed vqmmc-r9a09g057-regulator object to vqmmc-regulator
> > - Added regulator-compatible property for vqmmc-regulator
> > - Added 'renesas,sdhi-use-internal-regulator' property
>
> Thanks for the update!
>
> > --- a/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
> > +++ b/Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml
> > @@ -204,6 +207,31 @@ allOf:
> >          sectioned off to be run by a separate second clock source to allow
> >          the main core clock to be turned off to save power.
> >
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            const: renesas,sdhi-r9a09g057
> > +    then:
> > +      properties:
> > +        renesas,sdhi-use-internal-regulator:
> > +          $ref: /schemas/types.yaml#/definitions/flag
> > +          description:
> > +            Flag to indicate internal regulator is being used instead of GPIO regulator.
>
> Do you really need this?
For cases where the status is okay for the regulator but still the
user has phandle for the GPIO regulator or shall I drop this case?

> The status of the regulator subnode already indicates this.
You mean to use of_device_is_available() ?

>
> > +
> > +        vqmmc-regulator:
> > +          type: object
> > +          description: VQMMC SD regulator
> > +          $ref: /schemas/regulator/regulator.yaml#
> > +          unevaluatedProperties: false
> > +
> > +          properties:
> > +            regulator-compatible:
> > +              pattern: "^vqmmc-r9a09g057-regulator"
> > +
> > +      required:
> > +        - vqmmc-regulator
>
> I'm not 100% sure this works correctly: does the checker complain if
> a required subnode is disabled? Note that I haven't checked that.
>
Here is the experiment which I tried and the checker didnt complain,

&sdhi1 {
    status = "okay";
};

&vqmmc_sdhi1 {
    status = "disabled";
};

But the above is still a valid case where the user wants to use a GPIO
regulator?

Cheers,
Prabhakar