Re: [PATCH v5 0/5] Enable Remote GPIO over RPMSG on i.MX Platform

Arnaud POULIQUEN
2025-11-06T10:18:04Z

Hi Shenwei,

On 11/5/25 15:12, Shenwei Wang wrote:
> Hi Arnaud,
>
>> -----Original Message-----
>> From: Arnaud POULIQUEN <arnaud.pouliquen@foss.st.com>
>> Sent: Wednesday, November 5, 2025 4:26 AM
>> To: Peng Fan <peng.fan@nxp.com>; Shenwei Wang <shenwei.wang@nxp.com>;
>> Bjorn Andersson <andersson@kernel.org>; Mathieu Poirier
>> <mathieu.poirier@linaro.org>; Rob Herring <robh@kernel.org>; Krzysztof
>> Kozlowski <krzk+dt@kernel.org>; Conor Dooley <conor+dt@kernel.org>; Shawn
>> Guo <shawnguo@kernel.org>; Sascha Hauer <s.hauer@pengutronix.de>;
>> Jonathan Corbet <corbet@lwn.net>; Linus Walleij <linus.walleij@linaro.org>;
>> Bartosz Golaszewski <brgl@bgdev.pl>
>> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>; Fabio Estevam
>> <festevam@gmail.com>; linux-remoteproc@vger.kernel.org;
>> devicetree@vger.kernel.org; imx@lists.linux.dev; linux-arm-
>> kernel@lists.infradead.org; linux-kernel@vger.kernel.org; linux-
>> doc@vger.kernel.org; dl-linux-imx <linux-imx@nxp.com>; Randy Dunlap
>> <rdunlap@infradead.org>; Andrew Lunn <andrew@lunn.ch>; linux-
>> gpio@vger.kernel.org
>> Subject: [EXT] Re: [PATCH v5 0/5] Enable Remote GPIO over RPMSG on i.MX
>> Platform
>> Hi,
>>
>> On 11/5/25 02:12, Peng Fan wrote:
>>> Hi Shenwei
>>>
>>>> Subject: [PATCH v5 0/5] Enable Remote GPIO over RPMSG on i.MX
>>>> Platform
>>>>
>>>> Support the remote devices on the remote processor via the RPMSG bus
>>>> on i.MX platform.
>>>>
>>>
>>> I have not look into the details of new version, but before that, just
>>> want to check, have we agreed on what Arnaud suggested?
>>> or continue to proceed to be this as i.MX specific?
>>
>> Thanks, Peng, for pointing this out. Regarding the V3 discussions, it seems that I
>> am not the only one suggesting a generic driver.
>>
>
> As I mentioned before, the only i.MX-specific part is the transport protocol over the RPMSG bus.
> In this v5 patches, we’ve included detailed documentation for the protocol in a separate file. Any
> platform that follows the same protocol should work right out of the box.
>
> If you spot anything that could be improved, please let me know!

My concerns remain the same as those shared previously:

1) The simpler one: gpio-imx-rpmsg.c should be renamed to gpio-rpmsg.c.

2) The more complex one: the driver should be independent of the
remoteproc driver. The rpmsg protocol relies on virtio and can be used
in contexts other than remoteproc. In other words, the struct
rpmsg_driver and its associated operations should be defined within the
rpmsg-gpio driver, not in the remoteproc driver.

Thanks,
Arnaud

>
> Thanks,
> Shenwei
>
>> Thanks,
>> Arnaud
>>
>>>
>>> Thanks
>>> Peng.
>