diff mbox series

[RFC] pinctrl: pinmux: Introduce API to check if a pin is requested

Message ID 20241015162043.254517-1-prabhakar.mahadev-lad.rj@bp.renesas.com
State New
Headers show
Series [RFC] pinctrl: pinmux: Introduce API to check if a pin is requested | expand

Commit Message

Lad, Prabhakar Oct. 15, 2024, 4:20 p.m. UTC 
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(+)

Comments

Lad, Prabhakar Oct. 17, 2024, 8:47 a.m. UTC | #1 
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
diff mbox series

Patch

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)