linux-kernel - Re: [PATCH 1/3] dt-bindings: iio: imu: mpu6050: Add level shifter

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: <3b81a9a7-69a3-4fd6-875f-7a5170c5c872@linaro.org>
Date:   Mon, 25 Sep 2023 14:24:32 +0200
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Andreas Kemnade <andreas@...nade.info>,
        Jonathan Cameron <Jonathan.Cameron@...wei.com>
Cc:     jic23@...nel.org, lars@...afoo.de, robh+dt@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org,
        bcousson@...libre.com, tony@...mide.com,
        jean-baptiste.maneyrol@....com, chenhuiz@...s.com,
        andy.shevchenko@...il.com, linux-iio@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-omap@...r.kernel.org
Subject: Re: [PATCH 1/3] dt-bindings: iio: imu: mpu6050: Add level shifter

On 25/09/2023 13:02, Andreas Kemnade wrote:
> On Mon, 25 Sep 2023 11:28:52 +0100
> Jonathan Cameron <Jonathan.Cameron@...wei.com> wrote:
> 
>> On Mon, 25 Sep 2023 08:54:08 +0200
>> Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org> wrote:
>>
>>> On 25/09/2023 00:25, Andreas Kemnade wrote:  
>>>> Found in ancient platform data struct:
>>>> level_shifter: 0: VLogic, 1: VDD
>>>>
>>>> Signed-off-by: Andreas Kemnade <andreas@...nade.info>
>>>> ---
>>>>  .../devicetree/bindings/iio/imu/invensense,mpu6050.yaml         | 2 ++
>>>>  1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/iio/imu/invensense,mpu6050.yaml b/Documentation/devicetree/bindings/iio/imu/invensense,mpu6050.yaml
>>>> index 1db6952ddca5e..6aae2272fa15c 100644
>>>> --- a/Documentation/devicetree/bindings/iio/imu/invensense,mpu6050.yaml
>>>> +++ b/Documentation/devicetree/bindings/iio/imu/invensense,mpu6050.yaml
>>>> @@ -48,6 +48,8 @@ properties:
>>>>  
>>>>    mount-matrix: true
>>>>  
>>>> +  invensense,level-shifter: true    
>>>
>>> It does not look like you tested the bindings, at least after quick
>>> look. Please run `make dt_binding_check` (see
>>> Documentation/devicetree/bindings/writing-schema.rst for instructions).
>>> Maybe you need to update your dtschema and yamllint.
>>>
>>> Best regards,
>>> Krzysztof
>>>
>>>   
>>
>> Also this one isn't obvious - give it a description in the binding doc.
>>
>> I'm not sure of the arguement for calling it level shift in general.
>>
> I have no more descrption than the old source (see the citation from there)
> https://invensense.tdk.com/wp-content/uploads/2015/02/MPU-9150-Register-Map.pdf

I could not find any reference to level shift in this manual. To which
page and part do you refer?

> 
> does not list it. But that bit is needed to get things to work what also does the
> vendor kernel do.
> 
> What could be a better descrption?

I don't know, but something reasonable to you should be put there.

Best regards,
Krzysztof