linux-kernel - Re: [PATCH v5 3/3] arm64: dts: qcom: monaco-evk-camera: Add DT overlay

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] [day] [month] [year] [list]

Message-ID: <4b73f64a-1e28-4f25-80d2-3d59575b9da2@oss.qualcomm.com>
Date: Mon, 17 Nov 2025 13:37:45 +0100
From: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
To: Nihal Kumar Gupta <quic_nihalkum@...cinc.com>,
        Vikram Sharma <quic_vikramsa@...cinc.com>, bryan.odonoghue@...aro.org,
        mchehab@...nel.org, robh@...nel.org, krzk+dt@...nel.org,
        conor+dt@...nel.org, andersson@...nel.org, konradybcio@...nel.org,
        hverkuil-cisco@...all.nl, cros-qcom-dts-watchers@...omium.org,
        catalin.marinas@....com, will@...nel.org
Cc: linux-arm-kernel@...ts.infradead.org, quic_svankada@...cinc.com,
        linux-media@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        Ravi Shankar <quic_rshankar@...cinc.com>,
        Vishal Verma <quic_vishverm@...cinc.com>,
        Vladimir Zapolskiy <vladimir.zapolskiy@...aro.org>
Subject: Re: [PATCH v5 3/3] arm64: dts: qcom: monaco-evk-camera: Add DT
 overlay

On 11/15/25 6:53 AM, Nihal Kumar Gupta wrote:
> 
> 
> On 15-11-2025 03:49, Konrad Dybcio wrote:
>>> +&{/} {
>>> +	vreg_cam1_2p8: vreg-cam1-2p8 {
>> Where does this regulator lie physically? Is its presence dependent
>> on the connection of the sensor, is it part of the EVK carrier board,
>> or perhaps something else?
> vreg_cam1_2p8 is a fixed 2.8 V regulator located on the EVK carrier board. 
> It supplies the camera sensor’s AVDD rail and is enabled via GPIO 74, which is controlled by the TLMM block. 

Please keep this definition in the EVK board then. It would let one
reuse it for another consumer

> 
>>
>>> +		compatible = "regulator-fixed";
>>> +		regulator-name = "vreg_cam1_2p8";
>>> +		startup-delay-us = <10000>;
>>> +		enable-active-high;
>>> +		gpio = <&tlmm 74 GPIO_ACTIVE_HIGH>;
>>> +		pinctrl-names = "default";
>>> +		pinctrl-0 = <&cam1_avdd_2v8_en_default>;
>> property-n
>> property-names
>>
>> please
>>
> ACK
> 
>> [...]
>>
>>> +&tlmm {
>>> +	/*
>>> +	 * gpio67, gpio68, gpio69 provide MCLK0, MCLK1, MCLK2 for
>>> +	 * CAM0, CAM1 and CAM2 respectively via the "cam_mclk" function.
>>> +	 * So, here it's MCLK1 pin for instance.
>>> +	 */
>> I don't really see the value in these comments..
>>
>> Vladimir requested you to move the 'description' (meaning the node
>> describing the hardware, not a comment explaining the function of the
>> DT hunk in natural language) to monaco.dtsi too
> I’ve added descriptions to indicate which pins enable which camera MCLK/Regulators. If these aren’t considered useful, I can remove them.

Please do

> Should I need to add hardware descriptions for all GPIOs (gpio67–69 for MCLK and gpio73–75 for regulator enable), even if they are unused?

You're going to need them when you add support for other sensors, so I see
no reason why you'd not want to do it right away

> I have referenced qcs6490-rb3gen2-vision-mezzanine.dtso for the MCLK pin hardware description (cam1_default).
> All TLMM GPIOs mentioned above are muxed pins. As Bryan suggested in v4, these should go into the mezzanine-specific dtso. Do I need to extend this in monaco.dtsi as well?

These mux settings apply to any and all users of the mclk function, there
is nothing specific to this single mezzanine about it

Konrad