[PATCH v3 3/4] gpio: imx-rpmsg: add imx-rpmsg GPIO driver

[Shenwei Wang]

> -----Original Message-----
> From: Andrew Lunn <andrew at lunn.ch>
> Sent: Monday, October 13, 2025 9:56 AM
> To: Shenwei Wang <shenwei.wang at nxp.com>
> Cc: Bjorn Andersson <andersson at kernel.org>; Mathieu Poirier
> <mathieu.poirier at linaro.org>; Rob Herring <robh at kernel.org>; Krzysztof
> Kozlowski <krzk+dt at kernel.org>; Conor Dooley <conor+dt at kernel.org>; Shawn
> Guo <shawnguo at kernel.org>; Sascha Hauer <s.hauer at pengutronix.de>; Linus
> Walleij <linus.walleij at linaro.org>; Bartosz Golaszewski <brgl at bgdev.pl>;
> Pengutronix Kernel Team <kernel at pengutronix.de>; Fabio Estevam
> <festevam at gmail.com>; Peng Fan <peng.fan at nxp.com>; linux-
> remoteproc at vger.kernel.org; devicetree at vger.kernel.org; imx at lists.linux.dev;
> linux-arm-kernel at lists.infradead.org; linux-kernel at vger.kernel.org; dl-linux-imx
> <linux-imx at nxp.com>
> Subject: [EXT] Re: [PATCH v3 3/4] gpio: imx-rpmsg: add imx-rpmsg GPIO driver
> > > Maybe Documentation/admin-guide/gpio-rpmsg.rst would be better.  You
> > > should also document how to handle features the device does not
> > > support. e.g. i _think_ your hardware supports all 4 interrupt
> > > types. But maybe other hardware needs to return something meaning -
> EOPNOTSUP?
> > >
> >
> > That should be one type of the error return code in the out field of REPLY
> message.
> > The return code of 0 means success, and the others are error codes.
>
> You need to be careful of architecture code:
>
> https://elixir.bootl/
> in.com%2Flinux%2Fv6.17.1%2FA%2Fident%2FEOPNOTSUPP&data=05%7C02%7
> Cshenwei.wang%40nxp.com%7Ce2c6c89bb8cb41882a5208de0a68aa7b%7C686
> ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C638959641921284557%7CUn
> known%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIs
> IlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata
> =Lx%2B8iM3d8flgUq8kn8bnaDmxZDea8pPp2wL5V7JT%2BDM%3D&reserved=0
>
> Notice how ENOPNOTSUPP can be 45, 122, 223, or 95. Returning EL2NSYNC or
> EDQUOT to user space is going to cause confusion...
>

I think we should just follow the definitions in include/uapi/asm-generic/errno.h, right?

Thanks,
Shenwei

>        Andrew