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

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

[Christophe Leroy (CS GROUP)]

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);
-- 
2.54.0

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

[Bartosz Golaszewski]

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

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

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

[Herve Codina]

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

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

[Christophe Leroy (CS GROUP)]

Hi Hervé,

Le 29/07/2026 à 17:21, Herve Codina a écrit :
> 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?

As discussed together off-line, at the time being the par_io driver is 
not a platform driver. par_io_init() is called from setup_arch() by some 
board setups.

In order to fix the regression, I keep it minimal with an 
arch_initcall() function which is equivalent to what we had before 
changing this driver to a platform driver. It will also ease applying 
the fix to stable without too much churn.

It will still be possible to rework par_io driver in a follow-up patch 
and change it to a propoer platform driver.

Christophe

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

[Christophe Leroy (CS GROUP)]

On Wed, 29 Jul 2026 16:10:36 +0200, Christophe Leroy (CS GROUP) 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.
> 
> [...]

Applied, thanks!

[1/1] soc: fsl: qe: properly scan GPIO nodes at startup
      commit: cf91e5909e620b77164b53c9b316a5c1f11f9ea7

Best regards,
-- 
Christophe Leroy (CS GROUP) <chleroy@kernel.org>

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

[Herve Codina]

Hi Christophe,

On Thu, 30 Jul 2026 10:11:29 +0200
"Christophe Leroy (CS GROUP)" <chleroy@kernel.org> wrote:

> Hi Hervé,
> 
> Le 29/07/2026 à 17:21, Herve Codina a écrit :
> > 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?  
> 
> As discussed together off-line, at the time being the par_io driver is 
> not a platform driver. par_io_init() is called from setup_arch() by some 
> board setups.
> 
> In order to fix the regression, I keep it minimal with an 
> arch_initcall() function which is equivalent to what we had before 
> changing this driver to a platform driver. It will also ease applying 
> the fix to stable without too much churn.
> 
> It will still be possible to rework par_io driver in a follow-up patch 
> and change it to a propoer platform driver.
> 

Yes, indeed, this makes sense.

Thanks for the clarification.

Best regards,
Hervé