linux-kernel - Re: [PATCH v9 05/10] dt-bindings: clock: Add bindings for SP7021 clock driver

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: <39ce4a12-ff56-e0cf-b0b2-2a3545a9cb7f@canonical.com>
Date:   Mon, 28 Feb 2022 10:20:39 +0100
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>
To:     qinjian[覃健] <qinjian@...lus1.com>,
        "robh+dt@...nel.org" <robh+dt@...nel.org>
Cc:     "mturquette@...libre.com" <mturquette@...libre.com>,
        "sboyd@...nel.org" <sboyd@...nel.org>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "maz@...nel.org" <maz@...nel.org>,
        "p.zabel@...gutronix.de" <p.zabel@...gutronix.de>,
        "linux@...linux.org.uk" <linux@...linux.org.uk>,
        "broonie@...nel.org" <broonie@...nel.org>,
        "arnd@...db.de" <arnd@...db.de>,
        "stefan.wahren@...e.com" <stefan.wahren@...e.com>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-clk@...r.kernel.org" <linux-clk@...r.kernel.org>,
        Wells Lu 呂芳騰 <wells.lu@...plus.com>,
        Rob Herring <robh@...nel.org>
Subject: Re: [PATCH v9 05/10] dt-bindings: clock: Add bindings for SP7021
 clock driver

On 28/02/2022 07:31, qinjian[覃健] wrote:
>>> +examples:
>>> +  - |
>>> +    clkc: clock-controller@...00000 {
>>> +      compatible = "sunplus,sp7021-clkc";
>>> +      #clock-cells = <1>;
>>> +      reg = <0x9c000000 0x280>;
>>> +      clocks = <&extclk>, <&clkc PLL_SYS>;
>>
>> Except the warning pointed out by Rob's bot, it looks like you feed this
>> clock-controller with a clock from itself. Is there a point to express
>> it in DTS at all?
>  
> Yes, pllsys is an internal clock, but it also as a parent clock for some other
> clocks in this clock-controller.

What is the point to express it in DTS? Usually such internal
parent-child relation is described in the driver.

And how does it even work? How can you get a clock from a device before
you registered that device?


Best regards,
Krzysztof