linux-kernel - Re: [PATCH] arm64: dts: qcom: milos-fairphone-fp6: Add Hall Effect sensor

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: <DFUYB761EVX6.35AVTPBTUV0A6@fairphone.com>
Date: Thu, 22 Jan 2026 08:48:40 +0100
From: "Luca Weiss" <luca.weiss@...rphone.com>
To: "Dmitry Torokhov" <dmitry.torokhov@...il.com>, "Luca Weiss"
 <luca.weiss@...rphone.com>
Cc: "Dmitry Baryshkov" <dmitry.baryshkov@....qualcomm.com>, "Konrad Dybcio"
 <konrad.dybcio@....qualcomm.com>, "Bjorn Andersson" <andersson@...nel.org>,
 "Konrad Dybcio" <konradybcio@...nel.org>, "Rob Herring" <robh@...nel.org>,
 "Krzysztof Kozlowski" <krzk+dt@...nel.org>, "Conor Dooley"
 <conor+dt@...nel.org>, <~postmarketos/upstreaming@...ts.sr.ht>,
 <phone-devel@...r.kernel.org>, <linux-arm-msm@...r.kernel.org>,
 <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
 <linux-input@...r.kernel.org>
Subject: Re: [PATCH] arm64: dts: qcom: milos-fairphone-fp6: Add Hall Effect
 sensor

On Wed Jan 21, 2026 at 9:06 PM CET, Dmitry Torokhov wrote:
> On Wed, Jan 21, 2026 at 09:07:44AM +0100, Luca Weiss wrote:
>> On Wed Jan 21, 2026 at 12:05 AM CET, Dmitry Baryshkov wrote:
>> > On Mon, Jan 19, 2026 at 04:52:23PM +0100, Luca Weiss wrote:
>> >> On Mon Jan 19, 2026 at 3:41 PM CET, Konrad Dybcio wrote:
>> >> > On 1/16/26 3:22 PM, Luca Weiss wrote:
>> >> >> Add a node for the Hall Effect sensor, used to detect whether the Flip
>> >> >> Cover is closed or not.
>> >> >> 
>> >> >> The sensor is powered through vreg_l10b, so let's put a
>> >> >> regulator-always-on on that to make sure the sensor gets power.
>> >> >
>> >> > Is there anything else on L10B? Can we turn it off if the hall sensor
>> >> > is e.g. user-disabled?
>> >> 
>> >> It's the voltage source for pull-up of sensor I2C bus (so
>> >> ADSP-managed?), DVDD for amplifiers and VDD for a most sensors like
>> >> the gyro.
>> >> 
>> >> So realistically, it'll probably be (nearly) always on anyways. And I
>> >> don't want to shave another yak by adding vdd support to gpio-keys...
>> >
>> > Why? If it is exactly what happens on the board: the device producing
>> > GPIO events _is_ powered via a vdd. Added Input maintainer / list to cc.
>> 
>> Yes, the hall sensor which is connected to the GPIO on the SoC, has an
>> extra VDD input which needs to be on in order for the Hall-effect sensor
>> to be on.
>> 
>> See page 133 "HALL" in the center of the page
>> https://www.fairphone.com/wp-content/uploads/2025/08/Fairphone-Gen.-6_-Information-on-how-to-repair-dispose-of-and-recycle-EN-NL-FR-DE.pdf
>> 
>> The IC is OCH166AEV4AD where VDD is (as expected) "Power Supply Input":
>> https://www.orient-chip.com/Public/Uploads/uploadfile/files/20231014/1OCH166Adatasheet202203221.pdf
>
> If we add regulator support to gpio-keys do we expect it to be
> per-gpio/per-key? Or we'd recommend splitting into several instances of
> gpio-keys so that there is on set of supplies per gpio-keys device?

In my opinion it would fit in this case in the event-hall-sensor node,
that next to gpios = <&tlmm 70 GPIO_ACTIVE_LOW> we get a
vdd-supply = <&vreg_l10b>.

Regards
Luca

>
> Thanks.