Hi Andy,
On Mon, Oct 4, 2021 at 3:21 PM Andy Shevchenko andy.shevchenko@gmail.com wrote:
On Mon, Oct 4, 2021 at 3:45 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.
...
@@ -414,7 +421,8 @@ 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]));This is an unconditional call that will allocate the IRQ descriptor
If DEBUG and CONFIG_DYNAMIC_DEBUG* are not enabled, it's a no-op (protected by if (0) { ... }). If CONFIG_DYNAMIC_DEBUG is enabled, the operation is a no-op if not enabled dynamically (if (dynamic_checl) { ... }). If DEBUG (CONFIG_DEBUG_GPIO) is enabled, the output is wanted.
(yes, I've just checked the preprocessor and assembler output ;-).
even if we don't use it. Correct?
It calls .to_irq() of the parent GPIO controller, which is usually just doing some offset addition. But that's driver-dependent.
If so, I don't like this.
No worries, desc_to_gpio() and gpiod_to_irq() are only evaluated when the debug output is wanted.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds