Re: [PATCH v5 3/5] docs: staging: gpio-rpmsg: gpio over rpmsg bus

[Andrew Lunn]

On Wed, Nov 12, 2025 at 04:31:52PM +0000, Shenwei Wang wrote:
> 
> 
> > -----Original Message-----
> > From: Andrew Lunn <andrew@xxxxxxx>
> > Sent: Wednesday, November 12, 2025 7:42 AM
> > To: Shenwei Wang <shenwei.wang@xxxxxxx>
> > Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>; Bjorn Andersson
> > <andersson@xxxxxxxxxx>; Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>; Rob
> > Herring <robh@xxxxxxxxxx>; Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>; Conor
> > Dooley <conor+dt@xxxxxxxxxx>; Shawn Guo <shawnguo@xxxxxxxxxx>; Sascha
> > Hauer <s.hauer@xxxxxxxxxxxxxx>; Jonathan Corbet <corbet@xxxxxxx>; Bartosz
> > Golaszewski <brgl@xxxxxxxx>; Pengutronix Kernel Team
> > <kernel@xxxxxxxxxxxxxx>; Fabio Estevam <festevam@xxxxxxxxx>; Peng Fan
> > <peng.fan@xxxxxxx>; linux-remoteproc@xxxxxxxxxxxxxxx;
> > devicetree@xxxxxxxxxxxxxxx; imx@xxxxxxxxxxxxxxx; linux-arm-
> > kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-
> > doc@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>
> > Subject: [EXT] Re: [PATCH v5 3/5] docs: staging: gpio-rpmsg: gpio over rpmsg bus
> > 
> > Since this has not been merged yet, there are no existing systems.
> > 
> 
> In this context, "system" refers to both Linux and the remote firmware. The remote firmware 
> for i.MX platforms has already been released and widely used by our customers. Maintaining 
> compatibility with the existing firmware would provide a better solution for customers.

>From what i understand, this is not just GPIO. There is also I2C? And
RTC? I would expect a generic implementation of these as well? I find
it unlikely you can persuade all these subsystem Maintainers to accept
your protocols as is. You need to make changes so that GPIOs
interrupts work correctly, so i would just accept you need to change
the firmware. And i've given you a way you can keep backwards
compatible to your out of tree driver...

	  Andrew