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

Andrew Lunn
2025-11-14T17:39:12Z

On Wed, Nov 12, 2025 at 04:31:52PM +0000, Shenwei Wang wrote:
>
>
> > -----Original Message-----
> > From: Andrew Lunn <andrew@lunn.ch>
> > Sent: Wednesday, November 12, 2025 7:42 AM
> > To: Shenwei Wang <shenwei.wang@nxp.com>
> > Cc: Linus Walleij <linus.walleij@linaro.org>; 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>; Bartosz
> > Golaszewski <brgl@bgdev.pl>; Pengutronix Kernel Team
> > <kernel@pengutronix.de>; Fabio Estevam <festevam@gmail.com>; Peng Fan
> > <peng.fan@nxp.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>
> > 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