Geert Uytterhoeven
2021-Dec-03 14:06 UTC
[PATCH resend] gpio: aggregator: Add interrupt support
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 at 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