Re: [EXT] Re: [PATCH v5 01/11] dt-bindings: arm: fsl: add imx-se-fw binding doc

[Krzysztof Kozlowski]

On 28/08/2023 08:00, Varun Sethi wrote:
> Hi Greg,
> 
>> -----Original Message-----
>> From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>> Sent: Friday, August 25, 2023 12:54 AM
>> To: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
>> Cc: Rob Herring <robh@xxxxxxxxxx>; Pankaj Gupta
>> <pankaj.gupta@xxxxxxx>; shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx;
>> kernel@xxxxxxxxxxxxxx; clin@xxxxxxxx; conor+dt@xxxxxxxxxx;
>> pierre.gondois@xxxxxxx; Jacky Bai <ping.bai@xxxxxxx>; Clark Wang
>> <xiaoning.wang@xxxxxxx>; Wei Fang <wei.fang@xxxxxxx>; Peng Fan
>> <peng.fan@xxxxxxx>; Bough Chen <haibo.chen@xxxxxxx>;
>> festevam@xxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>;
>> davem@xxxxxxxxxxxxx; krzysztof.kozlowski+dt@xxxxxxxxxx; linux-arm-
>> kernel@xxxxxxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
>> kernel@xxxxxxxxxxxxxxx; Gaurav Jain <gaurav.jain@xxxxxxx>;
>> alexander.stein@xxxxxxxxxxxxxxx; Sahil Malhotra
>> <sahil.malhotra@xxxxxxx>; Aisheng Dong <aisheng.dong@xxxxxxx>; Varun
>> Sethi <V.Sethi@xxxxxxx>
>> Subject: [EXT] Re: [PATCH v5 01/11] dt-bindings: arm: fsl: add imx-se-fw
>> binding doc
>>
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>>
>> On Thu, Aug 24, 2023 at 08:45:41PM +0200, Krzysztof Kozlowski wrote:
>>> On 23/08/2023 14:43, Rob Herring wrote:
>>>>> +                                                          |
>>>>> +  +------------------------------------------------------ |
>>>>> +                     |             |           |          |
>>>>> +  userspace     /dev/ele_muXch0    |           |          |
>>>>> +                           /dev/ele_muXch1     |          |
>>>>> +                                         /dev/ele_muXchY  |
>>>>> +                                                          |
>>>>> +
>>>>> +  When a user sends a command to the firmware, it registers its
>>>>> + device_ctx  as waiter of a response from firmware.
>>>>> +
>>>>> +  A user can be registered as receiver of command from the ELE.
>>>>> +  Create char devices in /dev as channels of the form
>>>>> + /dev/ele_muXchY with X  the id of the driver and Y for each
>>>>> + users. It allows to send and receive  messages to the NXP
>>>>> + EdgeLock Enclave IP firmware on NXP SoC, where current  possible
>> value, i.e., supported SoC(s) are imx8ulp, imx93.
>>>>
>>>> Looks like a bunch of Linux details which don't belong in the binding.
>>>>
>>>> Why do you need your own custom interface to userspace? No one else
>>>> has a similar feature in their platforms? Something like virtio or
>>>> rpmsg doesn't work?
>>>
>>> +Cc Greg,
>>>
>>> I doubt they care. This is some stub-driver to pass messages from
>>> user-space to the firmware. The interface is undocumented, without
>>> examples and no user-space user.
>>
>> Great, no user?  Let's delete the code then :)
>>
> [Varun] We do have middleware applications that utilize the driver.
> Following
> are the links:
> https://github.com/nxp-imx/imx-secure-enclave
> https://github.com/nxp-imx/imx-smw
> 

Why this is not explained in the cover letter and in the patch adding
the interfaces? You still need to document and explain the interface.

Best regards,
Krzysztof