Re: [PATCH] soc: fsl: qe: properly scan GPIO nodes at startup

[Herve Codina <herve.codina@bootlin.com>]

Hi Christophe,

On Wed, 29 Jul 2026 16:10:36 +0200
"Christophe Leroy (CS GROUP)" <chleroy@kernel.org> wrote:

> Before commit 156460811def ("soc: fsl: qe: Change GPIO driver to a
> proper platform driver") qe_add_gpiochips() was walking the device
> tree to find all nodes with compatible "fsl,mpc8323-qe-pario-bank".
> 
> After that commit the discovery is handled by the platform core,
> therefore it is necessary to call of_platform_default_populate() on
> the par_io node.
> 
> Fixes: 156460811def ("soc: fsl: qe: Change GPIO driver to a proper platform driver")
> Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
> ---
>  drivers/soc/fsl/qe/qe_io.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/drivers/soc/fsl/qe/qe_io.c b/drivers/soc/fsl/qe/qe_io.c
> index a5e2d0e5ab51..02ca556c8db0 100644
> --- a/drivers/soc/fsl/qe/qe_io.c
> +++ b/drivers/soc/fsl/qe/qe_io.c
> @@ -15,6 +15,7 @@
>  #include <linux/errno.h>
>  #include <linux/module.h>
>  #include <linux/ioport.h>
> +#include <linux/of_platform.h>
>  
>  #include <asm/io.h>
>  #include <soc/fsl/qe/qe.h>
> @@ -184,3 +185,17 @@ int par_io_of_config(struct device_node *np)
>  	return 0;
>  }
>  EXPORT_SYMBOL(par_io_of_config);
> +
> +static int __init par_io_populate(void)
> +{
> +	struct device_node *np = of_find_node_by_name(NULL, "par_io");
> +
> +	if (!np)
> +		return 0;
> +
> +	of_platform_default_populate(np, NULL, NULL);
> +	of_node_put(np);
> +
> +	return 0;
> +}
> +arch_initcall(par_io_populate);


The par_io node is a sub-node of the soc@xxx node.
The soc@xxx node is simple-bus compatible. This child node should be
populated.

Why do we need this additional of_platform_default_populate?

Also par_io node has a compatible. Maybe the related driver should call
of_platform_populate() to populate children of par_io if needed. If this
driver is missing, maybe it should be created.

Do I miss something?

Best regards,
Hervé