-----Original Message-----
From: Andrew Lunn <andrew@lunn.ch>
Sent: Tuesday, February 24, 2026 12:27 PM
To: Shenwei Wang <shenwei.wang@nxp.com>
Cc: Arnaud POULIQUEN <arnaud.pouliquen@foss.st.com>; Linus Walleij
[off-list ref]; Bartosz Golaszewski [off-list ref]; Jonathan Corbet
[off-list ref]; Rob Herring [off-list ref]; Krzysztof Kozlowski
[off-list ref]; Conor Dooley [off-list ref]; Bjorn Andersson
[off-list ref]; Mathieu Poirier [off-list ref]; Frank Li
[off-list ref]; Sascha Hauer [off-list ref]; Shuah Khan
[off-list ref]; linux-gpio@vger.kernel.org; linux-
doc@vger.kernel.org; linux-kernel@vger.kernel.org; Pengutronix Kernel Team
[off-list ref]; Fabio Estevam [off-list ref]; Peng Fan
[off-list ref]; devicetree@vger.kernel.org; linux-
remoteproc@vger.kernel.org; imx@lists.linux.dev; linux-arm-
kernel@lists.infradead.org; dl-linux-imx [off-list ref]; Bartosz
Golaszewski [off-list ref]
Subject: [EXT] Re: [PATCH v8 3/4] gpio: rpmsg: add generic rpmsg GPIO driver

Caution: This is an external email. Please take care when clicking links or opening
attachments. When in doubt, report the message using the 'Report this email'
button

quoted

Regarding type, it’s needed, especially for the in packets. There are
two distinct kinds of incoming
packets: notification‑in and reply‑in. Because of that differences,
Combining cmd and type would blur that distinction and complicate the

implementation.

[Goes and looks at gpio-virtio]

They aren’t comparable. gpio‑virtio represents a single virtio device(transport) mapped to a single
GPIO controller — a strict 1:1 relationship.

RPMSG, on the other hand, is a bus‑style transport. Multiple GPIO controllers can run over
the same RPMSG channel.

Thanks,
Shenwei

https://elixir.bootl/
in.com%2Flinux%2Fv6.19.3%2Fsource%2Finclude%2Fuapi%2Flinux%2Fvirtio_gpio
.h%23L13&data=05%7C02%7Cshenwei.wang%40nxp.com%7C59d9438500554b
9d6a5e08de73d246cb%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C
639075544153317722%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRy
dWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D
%3D%7C0%7C%7C%7C&sdata=7fcyGY6KVuRqTIivhZbM4PK8PNTALI%2BScOfxM
yaPVh8%3D&reserved=0

/* Virtio GPIO request types */
#define VIRTIO_GPIO_MSG_GET_NAMES               0x0001
#define VIRTIO_GPIO_MSG_GET_DIRECTION           0x0002
#define VIRTIO_GPIO_MSG_SET_DIRECTION           0x0003
#define VIRTIO_GPIO_MSG_GET_VALUE               0x0004
#define VIRTIO_GPIO_MSG_SET_VALUE               0x0005
#define VIRTIO_GPIO_MSG_IRQ_TYPE                0x0006

        Andrew