> -----Original Message-----
> From: Andrew Davis <[email protected]>
> Sent: Thursday, June 25, 2026 3:32 PM
...
> Subject: Re: [PATCH v14 4/5] gpio: rpmsg: add generic rpmsg GPIO driver
> > + Say yes here to support the generic GPIO functions over the RPMSG
> > + bus. Currently supported devices: i.MX7ULP, i.MX8ULP, i.MX8x, and
> > + i.MX9x.
>
> The support would depend on if the right firmware is loaded/running on the
> given
> remote core. Also if you want to make this generic, then any vendor should be
> able to make a firmware that implements this protocol and make use of this
> driver.
> Suggest dropping this NXP specific device list.
>
Agree.
> > +
> > + If unsure, say N.
> > +
> > +endmenu
> > +
> > menu "SPI GPIO expanders"
> > depends on SPI_MASTER
> >
> > diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index
> > b267598b517d..ee75c0e65b8b 100644
> > --- a/drivers/gpio/Makefile
> > +++ b/drivers/gpio/Makefile
> > @@ -157,6 +157,7 @@ obj-$(CONFIG_GPIO_RDC321X) += gpio-
...
> > +
> > +static int rpmsg_gpio_channel_probe(struct rpmsg_device *rpdev) {
> > + struct device *dev = &rpdev->dev;
> > + struct device_node *np;
> > + const char *rproc_name;
> > + int idx;
> > +
> > + idx = rpmsg_get_gpio_index(rpdev->id.name, CHAN_NAME_PREFIX);
> > + if (idx < 0)
> > + return -EINVAL;
> > +
> > + if (!dev->of_node) {
> > + np = rpmsg_get_channel_ofnode(rpdev, GPIO_COMPAT_STR, idx);
> > + if (!np)
> > + return -ENODEV;
>
> This seems to imply that DT nodes are required. RPMSG is a discoverable bus
> with a nameservice that can bind/probe new devices. While then optionally
> binding to a DT node when available so sub-devices can be described in DT is
> fine,
> I don't see why it should be required.
>
First, a GPIO node typically acts as a provider for other devices.
Second, by requiring a DT node, we can ensure that only explicitly enabled GPIO
resources are managed and accessible.
> > +static struct rpmsg_driver rpmsg_gpio_channel_client = {
> > + .callback = rpmsg_gpio_channel_callback,
> > + .id_table = rpmsg_gpio_channel_id_table,
> > + .probe = rpmsg_gpio_channel_probe,
> > + .drv = {
> > + .name = KBUILD_MODNAME,
> > + .of_match_table = rpmsg_gpio_dt_ids,
>
> Does this line actually do anything anymore? Maybe it did when this was a
> platform_driver, but this is a rpmsg_driver and will probe though .id_table
> matches.
>
Yes, it can be removed because the driver will find the dt node on its own.
Thanks,
Shenwei
> Andrew
>
> > + },
> > +};
> > +module_rpmsg_driver(rpmsg_gpio_channel_client);
> > +
> > +MODULE_AUTHOR("Shenwei Wang <[email protected]>");
> > +MODULE_DESCRIPTION("generic rpmsg gpio driver");
> > +MODULE_LICENSE("GPL");
>
