[1/2] pinctrl: starfive: jh7110: ignore disabled device tree nodes

The driver always registers pin configurations in device tree. This can
cause some inconvenience to users, as pin configurations in the base
device tree cannot be disabled in the device tree overlay, even when the
relevant devices are not used.

Ignore disabled pin configuration nodes in device tree.

Fixes: 447976ab62c5 ("pinctrl: starfive: Add StarFive JH7110 sys controller driver")
Cc: stable@vger.kernel.org
Signed-off-by: Nam Cao <namcao@linutronix.de>
---
 drivers/pinctrl/starfive/pinctrl-starfive-jh7110.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Emil Renner Berthing wrote:
> Nam Cao wrote:
> > The driver always registers pin configurations in device tree. This can
> > cause some inconvenience to users, as pin configurations in the base
> > device tree cannot be disabled in the device tree overlay, even when the
> > relevant devices are not used.
> >
> > Ignore disabled pin configuration nodes in device tree.
> >
> > Fixes: ec648f6b7686 ("pinctrl: starfive: Add pinctrl driver for StarFive SoCs")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Nam Cao <namcao@linutronix.de>
> > ---
> >  drivers/pinctrl/starfive/pinctrl-starfive-jh7100.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/pinctrl/starfive/pinctrl-starfive-jh7100.c b/drivers/pinctrl/starfive/pinctrl-starfive-jh7100.c
> > index 530fe340a9a1..561fd0c6b9b0 100644
> > --- a/drivers/pinctrl/starfive/pinctrl-starfive-jh7100.c
> > +++ b/drivers/pinctrl/starfive/pinctrl-starfive-jh7100.c
> > @@ -492,7 +492,7 @@ static int starfive_dt_node_to_map(struct pinctrl_dev *pctldev,
> >
> >  	nmaps = 0;
> >  	ngroups = 0;
> > -	for_each_child_of_node(np, child) {
> > +	for_each_available_child_of_node(np, child) {
>
> Hi Nam,
>
> Is this safe to do? I mean will the children considered "available" not change
> as drivers are loaded during boot so this is racy?

I just noticed the Allwinner D1 device trees use /omit-if-no-ref/ in front of
the pin group nodes. I think all current pin group nodes (for the JH7100 at
least) are used by some peripheral, so if you're removing peripherals from the
device tree you should be removing the reference too and this scheme should
work for you.

/Emil

On Fri, Dec 01, 2023 at 03:43:04PM +0100, Emil Renner Berthing wrote:
> I just noticed the Allwinner D1 device trees use /omit-if-no-ref/ in front of
> the pin group nodes. I think all current pin group nodes (for the JH7100 at
> least) are used by some peripheral, so if you're removing peripherals from the
> device tree you should be removing the reference too and this scheme should
> work for you.

If I am not mistaken, /omit-if-no-ref/ (and similar stuffs like
/delete-node/ and /delete-property/) is only for compile-time node
removal. It doesn't do anything with device tree overlay.

Best regards,
Nam

On Fri, Dec 1, 2023 at 10:23 AM Nam Cao <namcao@linutronix.de> wrote:

> The driver always registers pin configurations in device tree. This can
> cause some inconvenience to users, as pin configurations in the base
> device tree cannot be disabled in the device tree overlay, even when the
> relevant devices are not used.
>
> Ignore disabled pin configuration nodes in device tree.
>
> Fixes: 447976ab62c5 ("pinctrl: starfive: Add StarFive JH7110 sys controller driver")
> Cc: stable@vger.kernel.org
> Signed-off-by: Nam Cao <namcao@linutronix.de>

This patch (1/2) applied for fixes.

Yours,
Linus Walleij