diff mbox series

[resend] gpio: aggregator: Add interrupt support

Message ID ba7f82f348d77b6a65498dd13a92550949e69cc3.1638540167.git.geert+renesas@glider.be
State New
Headers show
Series [resend] gpio: aggregator: Add interrupt support | expand

Commit Message

Geert Uytterhoeven Dec. 3, 2021, 2:06 p.m. UTC
Currently the GPIO Aggregator does not support interrupts.  This means
that kernel drivers going from a GPIO to an IRQ using gpiod_to_irq(),
and userspace applications using line events do not work.

Add interrupt support by providing a gpio_chip.to_irq() callback, which
just calls into the parent GPIO controller.

Note that this does not implement full interrupt controller (irq_chip)
support, so using e.g. gpio-keys with "interrupts" instead of "gpios"
still does not work.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
I would prefer to avoid implementing irq_chip support, until there is a
real use case for this.

This has been tested with gpio-keys and gpiomon on the Koelsch
development board:

  - gpio-keys, using a DT overlay[1]:

	$ overlay add r8a7791-koelsch-keyboard-controlled-led
	$ echo gpio-aggregator > /sys/devices/platform/frobnicator/driver_override
	$ echo frobnicator > /sys/bus/platform/drivers/gpio-aggregator/bind

	$ gpioinfo frobnicator
	gpiochip12 - 3 lines:
		line   0:      "light"      "light"  output  active-high [used]
		line   1:         "on"         "On"   input   active-low [used]
		line   2:        "off"        "Off"   input   active-low [used]

	$ echo 255 > /sys/class/leds/light/brightness
	$ echo 0 > /sys/class/leds/light/brightness

	$ evtest /dev/input/event0

  - gpiomon, using the GPIO sysfs API:

	$ echo keyboard > /sys/bus/platform/drivers/gpio-keys/unbind
	$ echo e6055800.gpio 2,6 > /sys/bus/platform/drivers/gpio-aggregator/new_device
	$ gpiomon gpiochip12 0 1

[1] "ARM: dts: koelsch: Add overlay for keyboard-controlled LED"
    https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/commit/?h=topic/renesas-overlays&id=c78d817869e63a3485bb4ab98aeea6ce368a396e
---
 drivers/gpio/gpio-aggregator.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Comments

Bartosz Golaszewski Dec. 3, 2021, 2:56 p.m. UTC | #1
On Fri, Dec 3, 2021 at 3:06 PM Geert Uytterhoeven
<geert+renesas@glider.be> wrote:
>
> Currently the GPIO Aggregator does not support interrupts.  This means
> that kernel drivers going from a GPIO to an IRQ using gpiod_to_irq(),
> and userspace applications using line events do not work.
>
> Add interrupt support by providing a gpio_chip.to_irq() callback, which
> just calls into the parent GPIO controller.
>
> Note that this does not implement full interrupt controller (irq_chip)
> support, so using e.g. gpio-keys with "interrupts" instead of "gpios"
> still does not work.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> I would prefer to avoid implementing irq_chip support, until there is a
> real use case for this.
>
> This has been tested with gpio-keys and gpiomon on the Koelsch
> development board:
>
>   - gpio-keys, using a DT overlay[1]:
>
>         $ overlay add r8a7791-koelsch-keyboard-controlled-led
>         $ echo gpio-aggregator > /sys/devices/platform/frobnicator/driver_override
>         $ echo frobnicator > /sys/bus/platform/drivers/gpio-aggregator/bind
>
>         $ gpioinfo frobnicator
>         gpiochip12 - 3 lines:
>                 line   0:      "light"      "light"  output  active-high [used]
>                 line   1:         "on"         "On"   input   active-low [used]
>                 line   2:        "off"        "Off"   input   active-low [used]
>
>         $ echo 255 > /sys/class/leds/light/brightness
>         $ echo 0 > /sys/class/leds/light/brightness
>
>         $ evtest /dev/input/event0
>
>   - gpiomon, using the GPIO sysfs API:
>
>         $ echo keyboard > /sys/bus/platform/drivers/gpio-keys/unbind
>         $ echo e6055800.gpio 2,6 > /sys/bus/platform/drivers/gpio-aggregator/new_device
>         $ gpiomon gpiochip12 0 1
>
> [1] "ARM: dts: koelsch: Add overlay for keyboard-controlled LED"
>     https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/commit/?h=topic/renesas-overlays&id=c78d817869e63a3485bb4ab98aeea6ce368a396e
> ---
>  drivers/gpio/gpio-aggregator.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
> index e9671d1660ef4b40..869dc952cf45218b 100644
> --- a/drivers/gpio/gpio-aggregator.c
> +++ b/drivers/gpio/gpio-aggregator.c
> @@ -371,6 +371,13 @@ static int gpio_fwd_set_config(struct gpio_chip *chip, unsigned int offset,
>         return gpiod_set_config(fwd->descs[offset], config);
>  }
>
> +static int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset)
> +{
> +       struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
> +
> +       return gpiod_to_irq(fwd->descs[offset]);
> +}
> +
>  /**
>   * gpiochip_fwd_create() - Create a new GPIO forwarder
>   * @dev: Parent device pointer
> @@ -411,7 +418,8 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
>         for (i = 0; i < ngpios; i++) {
>                 struct gpio_chip *parent = gpiod_to_chip(descs[i]);
>
> -               dev_dbg(dev, "%u => gpio-%d\n", i, desc_to_gpio(descs[i]));
> +               dev_dbg(dev, "%u => gpio %d irq %d\n", i,
> +                       desc_to_gpio(descs[i]), gpiod_to_irq(descs[i]));
>
>                 if (gpiod_cansleep(descs[i]))
>                         chip->can_sleep = true;
> @@ -429,6 +437,7 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
>         chip->get_multiple = gpio_fwd_get_multiple_locked;
>         chip->set = gpio_fwd_set;
>         chip->set_multiple = gpio_fwd_set_multiple_locked;
> +       chip->to_irq = gpio_fwd_to_irq;
>         chip->base = -1;
>         chip->ngpio = ngpios;
>         fwd->descs = descs;
> --
> 2.25.1
>

Applied, thanks!

Bart
Bartosz Golaszewski Dec. 3, 2021, 2:58 p.m. UTC | #2
On Fri, Dec 3, 2021 at 3:56 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
>
> On Fri, Dec 3, 2021 at 3:06 PM Geert Uytterhoeven
> <geert+renesas@glider.be> wrote:
> >
> > Currently the GPIO Aggregator does not support interrupts.  This means
> > that kernel drivers going from a GPIO to an IRQ using gpiod_to_irq(),
> > and userspace applications using line events do not work.
> >
> > Add interrupt support by providing a gpio_chip.to_irq() callback, which
> > just calls into the parent GPIO controller.
> >
> > Note that this does not implement full interrupt controller (irq_chip)
> > support, so using e.g. gpio-keys with "interrupts" instead of "gpios"
> > still does not work.
> >
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > ---
> > I would prefer to avoid implementing irq_chip support, until there is a
> > real use case for this.
> >
> > This has been tested with gpio-keys and gpiomon on the Koelsch
> > development board:
> >
> >   - gpio-keys, using a DT overlay[1]:
> >
> >         $ overlay add r8a7791-koelsch-keyboard-controlled-led
> >         $ echo gpio-aggregator > /sys/devices/platform/frobnicator/driver_override
> >         $ echo frobnicator > /sys/bus/platform/drivers/gpio-aggregator/bind
> >
> >         $ gpioinfo frobnicator
> >         gpiochip12 - 3 lines:
> >                 line   0:      "light"      "light"  output  active-high [used]
> >                 line   1:         "on"         "On"   input   active-low [used]
> >                 line   2:        "off"        "Off"   input   active-low [used]
> >
> >         $ echo 255 > /sys/class/leds/light/brightness
> >         $ echo 0 > /sys/class/leds/light/brightness
> >
> >         $ evtest /dev/input/event0
> >
> >   - gpiomon, using the GPIO sysfs API:
> >
> >         $ echo keyboard > /sys/bus/platform/drivers/gpio-keys/unbind
> >         $ echo e6055800.gpio 2,6 > /sys/bus/platform/drivers/gpio-aggregator/new_device
> >         $ gpiomon gpiochip12 0 1
> >
> > [1] "ARM: dts: koelsch: Add overlay for keyboard-controlled LED"
> >     https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/commit/?h=topic/renesas-overlays&id=c78d817869e63a3485bb4ab98aeea6ce368a396e
> > ---
> >  drivers/gpio/gpio-aggregator.c | 11 ++++++++++-
> >  1 file changed, 10 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
> > index e9671d1660ef4b40..869dc952cf45218b 100644
> > --- a/drivers/gpio/gpio-aggregator.c
> > +++ b/drivers/gpio/gpio-aggregator.c
> > @@ -371,6 +371,13 @@ static int gpio_fwd_set_config(struct gpio_chip *chip, unsigned int offset,
> >         return gpiod_set_config(fwd->descs[offset], config);
> >  }
> >
> > +static int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset)
> > +{
> > +       struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
> > +
> > +       return gpiod_to_irq(fwd->descs[offset]);
> > +}
> > +
> >  /**
> >   * gpiochip_fwd_create() - Create a new GPIO forwarder
> >   * @dev: Parent device pointer
> > @@ -411,7 +418,8 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
> >         for (i = 0; i < ngpios; i++) {
> >                 struct gpio_chip *parent = gpiod_to_chip(descs[i]);
> >
> > -               dev_dbg(dev, "%u => gpio-%d\n", i, desc_to_gpio(descs[i]));
> > +               dev_dbg(dev, "%u => gpio %d irq %d\n", i,
> > +                       desc_to_gpio(descs[i]), gpiod_to_irq(descs[i]));
> >
> >                 if (gpiod_cansleep(descs[i]))
> >                         chip->can_sleep = true;
> > @@ -429,6 +437,7 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
> >         chip->get_multiple = gpio_fwd_get_multiple_locked;
> >         chip->set = gpio_fwd_set;
> >         chip->set_multiple = gpio_fwd_set_multiple_locked;
> > +       chip->to_irq = gpio_fwd_to_irq;
> >         chip->base = -1;
> >         chip->ngpio = ngpios;
> >         fwd->descs = descs;
> > --
> > 2.25.1
> >
>
> Applied, thanks!
>
> Bart

Eek, missed the explanation.

I think this is fine. For user-space eventual switch to a real
irq_chip won't break anything so let's take it.

Bart
diff mbox series

Patch

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index e9671d1660ef4b40..869dc952cf45218b 100644
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -371,6 +371,13 @@  static int gpio_fwd_set_config(struct gpio_chip *chip, unsigned int offset,
 	return gpiod_set_config(fwd->descs[offset], config);
 }
 
+static int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset)
+{
+	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
+
+	return gpiod_to_irq(fwd->descs[offset]);
+}
+
 /**
  * gpiochip_fwd_create() - Create a new GPIO forwarder
  * @dev: Parent device pointer
@@ -411,7 +418,8 @@  static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
 	for (i = 0; i < ngpios; i++) {
 		struct gpio_chip *parent = gpiod_to_chip(descs[i]);
 
-		dev_dbg(dev, "%u => gpio-%d\n", i, desc_to_gpio(descs[i]));
+		dev_dbg(dev, "%u => gpio %d irq %d\n", i,
+			desc_to_gpio(descs[i]), gpiod_to_irq(descs[i]));
 
 		if (gpiod_cansleep(descs[i]))
 			chip->can_sleep = true;
@@ -429,6 +437,7 @@  static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
 	chip->get_multiple = gpio_fwd_get_multiple_locked;
 	chip->set = gpio_fwd_set;
 	chip->set_multiple = gpio_fwd_set_multiple_locked;
+	chip->to_irq = gpio_fwd_to_irq;
 	chip->base = -1;
 	chip->ngpio = ngpios;
 	fwd->descs = descs;