From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Introduce `pin_requestesd` API to check if a pin is currently requested.
This API allows pinctrl drivers to verify whether a pin is requested or
not by checking if the pin is owned by either `gpio_owner` or `mux_owner`.

GPIO pins used as interrupts through the `interrupts` DT property do not
follow the usual `gpio_request`/`pin_request` path, unlike GPIO pins used
as interrupts via the `gpios` property. As a result, such pins were
reported as `UNCLAIMED` in the `pinmux-pins` sysfs file, even though they
were in use as interrupts.

With the newly introduced API, pinctrl drivers can check if a pin is
already requested by the pinctrl core and ensure that pin is requested
during when using as irq. This helps to ensure that the `pinmux-pins`
sysfs file reflects the correct status of the pin.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 drivers/pinctrl/pinmux.c | 14 ++++++++++++++
 drivers/pinctrl/pinmux.h |  5 +++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
index 02033ea1c643..19c68e174c36 100644
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -99,6 +99,20 @@ bool pinmux_can_be_used_for_gpio(struct pinctrl_dev *pctldev, unsigned int pin)
 	return !(ops->strict && !!desc->gpio_owner);
 }
 
+bool pin_requestesd(struct pinctrl_dev *pctldev, int pin)
+{
+	struct pin_desc *desc;
+
+	desc = pin_desc_get(pctldev, pin);
+	if (!desc)
+		return false;
+
+	if (!desc->gpio_owner && !desc->mux_owner)
+		return false;
+
+	return true;
+}
+
 /**
  * pin_request() - request a single pin to be muxed in, typically for GPIO
  * @pctldev: the associated pin controller device
diff --git a/drivers/pinctrl/pinmux.h b/drivers/pinctrl/pinmux.h
index 2965ec20b77f..550cb3b4c068 100644
--- a/drivers/pinctrl/pinmux.h
+++ b/drivers/pinctrl/pinmux.h
@@ -42,6 +42,7 @@ int pinmux_map_to_setting(const struct pinctrl_map *map,
 void pinmux_free_setting(const struct pinctrl_setting *setting);
 int pinmux_enable_setting(const struct pinctrl_setting *setting);
 void pinmux_disable_setting(const struct pinctrl_setting *setting);
+bool pin_requestesd(struct pinctrl_dev *pctldev, int pin);
 
 #else
 
@@ -100,6 +101,10 @@ static inline void pinmux_disable_setting(const struct pinctrl_setting *setting)
 {
 }
 
+bool pin_requestesd(struct pinctrl_dev *pctldev, int pin)
+{
+	return false;
+}
 #endif
 
 #if defined(CONFIG_PINMUX) && defined(CONFIG_DEBUG_FS)
-- 
2.43.0

Hi Prabhakar,

thanks for your patch!

On Tue, Oct 15, 2024 at 6:21 PM Prabhakar <prabhakar.csengg@gmail.com> wrote:


> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Introduce `pin_requestesd` API to check if a pin is currently requested.

What kind of function name is this?

Do you mean

pin_requested()?

> This API allows pinctrl drivers to verify whether a pin is requested or
> not by checking if the pin is owned by either `gpio_owner` or `mux_owner`.

There is nothing wrong with the patch as such, but it needs to be
illustrated by submitting it together with the first intended user
and show how it is used, we don't add upfront APIs.

Yours,
Linus Walleij

Hi Linus,

Thank you for the review.

On Tue, Oct 15, 2024 at 10:43 PM Linus Walleij <linus.walleij@linaro.org> wrote:
>
> Hi Prabhakar,
>
> thanks for your patch!
>
> On Tue, Oct 15, 2024 at 6:21 PM Prabhakar <prabhakar.csengg@gmail.com> wrote:
>
>
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >
> > Introduce `pin_requestesd` API to check if a pin is currently requested.
>
> What kind of function name is this?
>
> Do you mean
>
> pin_requested()?
>
Ouch, I will fix that.

> > This API allows pinctrl drivers to verify whether a pin is requested or
> > not by checking if the pin is owned by either `gpio_owner` or `mux_owner`.
>
> There is nothing wrong with the patch as such, but it needs to be
> illustrated by submitting it together with the first intended user
> and show how it is used, we don't add upfront APIs.
>
Sure, I will post the patches.

Cheers,
Prabhakar