linux-kernel - Re: [PATCH 2/2] ARM: DTS: Add devicetree file for the Galaxy S2

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <d9fe575926342b355f76e1f38fef62f0d7d38075.camel@gmail.com>
Date:   Tue, 31 Mar 2020 17:29:56 +0200
From:   Paweł Chmiel <pawel.mikolaj.chmiel@...il.com>
To:     Marek Szyprowski <m.szyprowski@...sung.com>,
        Paul Cercueil <paul@...pouillou.net>
Cc:     Krzysztof Kozlowski <krzk@...nel.org>,
        Kukjin Kim <kgene@...nel.org>,
        Rob Herring <robh+dt@...nel.org>, mark.rutland@....com,
        Stenkin Evgeniy <stenkinevgeniy@...il.com>,
        linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] ARM: DTS: Add devicetree file for the Galaxy S2

On Tue, 2020-03-31 at 15:55 +0200, Marek Szyprowski wrote:
> Hi Paul,
> 
> On 2020-03-31 15:09, Paul Cercueil wrote:
> > Cc: Paweł Chmiel <pawel.mikolaj.chmiel@...il.com>
> > 
> > Hi Marek,
> > 
> > Le mar. 31 mars 2020 à 7:36, Marek Szyprowski 
> > <m.szyprowski@...sung.com> a écrit :
> > > Hi Paul,
> > > 
> > > On 2020-03-18 15:25, Paul Cercueil wrote:
> > > > > >   +    };
> > > > > >   +
> > > > > >   +    tsp_reg: regulator-1 {
> > > > > >   +        compatible = "regulator-fixed";
> > > > > >   +        regulator-name = "TSP_FIXED_VOLTAGES";
> > > > > >   +        regulator-min-microvolt = <3300000>;
> > > > > >   +        regulator-max-microvolt = <3300000>;
> > > > > >   +        gpio = <&gpl0 3 GPIO_ACTIVE_HIGH>;
> > > > > >   +        startup-delay-us = <70000>;
> > > > > >   +        enable-active-high;
> > > > > >   +        regulator-boot-on;
> > > > > >   +        regulator-always-on;
> > > > > 
> > > > >  always-on and boot-on should not be needed. You have a consumer 
> > > > > for this
> > > > >  regulator.
> > > > 
> > > >  About this: the touchscreen driver does not use a regulator, so I
> > > >  believe that's why these properties were here.
> > > > 
> > > >  I sent patches upstream to address the issue:
> > > >  https://protect2.fireeye.com/url?k=e8aedc29-b53072b3-e8af5766-0cc47a336fae-759579fd576d8382&u=https://lkml.org/lkml/2020/3/15/94 
> > > > 
> > > > 
> > > >  I believe this means I cannot merge the i9100 devicetree until it is
> > > >  acked.
> > > 
> > > One more information - similar change has been already posted, but it
> > > looks it got lost then: https://patchwork.kernel.org/patch/10550903/
> > 
> > I was aware of this patch, but didn't know it was sent upstream.
> > 
> > This other patch uses two regulators, vdd/avdd but doesn't give any 
> > reason why.
> > 
> I've checked the UniversalC210 schematic, which uses the same 
> touchscreen chip. There are 2 supplies to the touchscreen chip: 2.8V VDD 
> and 3.3V AVDD. Both are enabled by the same GPIO pin though. There is 
> however no reset GPIO pin there.
Hi
Don't remember now how it worked on Galaxy S1, but it looks like it has
the same setup - two regulators enabled by one GPIO pin.
> 
> > Paweł, is that really needed?
> > 
> Best regards