linux-kernel - Re: [PATCH 07/15] dt-bindings: clock: Add Ambarella clock bindings

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: <185f7c1c693.b1cad2b8487563.1022046142491625830@linux.beauty>
Date:   Sat, 28 Jan 2023 17:42:29 +0800
From:   Li Chen <me@...ux.beauty>
To:     "Krzysztof Kozlowski" <krzysztof.kozlowski@...aro.org>
Cc:     "li chen" <lchen@...arella.com>,
        "michael turquette" <mturquette@...libre.com>,
        "stephen boyd" <sboyd@...nel.org>,
        "rob herring" <robh+dt@...nel.org>,
        "krzysztof kozlowski" <krzysztof.kozlowski+dt@...aro.org>,
        "moderated list:arm/ambarella soc support" 
        <linux-arm-kernel@...ts.infradead.org>,
        "open list:common clk framework" <linux-clk@...r.kernel.org>,
        "open list:open firmware and flattened device tree bindings" 
        <devicetree@...r.kernel.org>,
        "open list" <linux-kernel@...r.kernel.org>,
        "arnd bergmann" <arnd@...db.de>
Subject: Re: [PATCH 07/15] dt-bindings: clock: Add Ambarella clock bindings

Hi Krzysztof,

 ---- On Fri, 27 Jan 2023 23:08:09 +0800  Krzysztof Kozlowski  wrote --- 
 > On 27/01/2023 15:48, Li Chen wrote:
 > >  > 
 > >  > but what you are saying is that there is no separate clock controller
 > >  > device with its own IO address but these clocks are part of rct_syscon.
 > >  > Then model it that way in DTS. The rct_syscon is then your clock
 > >  > controller and all these fake gclk-core and gclk-ddr nodes should be gone.
 > > 
 > > Ok, I will remove these fake nodes, and model the hardware as:
 > > 
 > > rct_syscon node
 > > | clock node(pll, div, mux, composite  clocks live in the same driver)
 > > | other periphal nodes
 > 
 > You need clock node if it takes any resources. If it doesn't, you do not
 > need it.

Got it, I will model it as:

rct_syscon(compatible include "ambarella, <SoC>-clock"...)
| peripheral A
| peripheral B
| ...


One more question, two driver models:
a. compatible = "ambarella, <SoC>-clock", handle all clocks(pll, div, mux, composite) in single driver.
b. compatible = "ambarella, <SoC>-pll-clock", "ambarella, <SoC>-composite-clock", "ambarella, <SoC>-div-clock"...... 
    and implement a driver for each of them.

Which driver model is preferred?

Regards,
Li