linux-kernel - Re: [PATCH 0/2] i2c: at91: Add support for programmable clock source

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

Message-ID: <8a775c67-00a3-1dbe-daa3-09a537f482d8@microchip.com>
Date:   Wed, 13 Oct 2021 08:49:20 +0000
From:   <Codrin.Ciubotariu@...rochip.com>
To:     <Horatiu.Vultur@...rochip.com>, <robh+dt@...nel.org>,
        <Nicolas.Ferre@...rochip.com>, <alexandre.belloni@...tlin.com>,
        <Ludovic.Desroches@...rochip.com>, <linux-i2c@...r.kernel.org>,
        <devicetree@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 0/2] i2c: at91: Add support for programmable clock source

On 12.10.2021 17:07, Horatiu Vultur wrote:
> Add support to be able to set BRSRCCLK. This feature is support on lan966x
> 
> Horatiu Vultur (2):
>    dt-bindings: i2c: at91: Extend compatible list for lan966x
>    i2c: at91: add support for brsrcclk
> 
>   .../devicetree/bindings/i2c/i2c-at91.txt      |  6 +++--
>   drivers/i2c/busses/i2c-at91-core.c            | 16 +++++++++++++
>   drivers/i2c/busses/i2c-at91-master.c          | 23 +++++++++++++++++--
>   drivers/i2c/busses/i2c-at91.h                 |  1 +
>   4 files changed, 42 insertions(+), 4 deletions(-)
> 

Hi Horatiu,

 From what I understand, on your DTS, you replaced the peripheral clock 
with the GCLK in the I2C node. This means that you are forcing all the 
variants that support clk_brsrcclk to treat the current clock as GCLK. 
This is not necessarily correct, since this newer variants can also work 
fine with only the peripheral clock and we should keep these option 
available.

I would add an optional GCLK clock binding in the I2C node. This way 
GCLK will be used only if it is present in DT and clk_brsrcclk set.

Best regards,
Codrin