On Thu, Oct 29, 2020 at 7:32 PM Ricardo Ribalda <ribalda@xxxxxxxxxx> wrote: > On Thu, Oct 29, 2020 at 6:26 PM Andy Shevchenko > <andy.shevchenko@xxxxxxxxx> wrote: > > On Thu, Oct 29, 2020 at 7:20 PM Andy Shevchenko > > <andy.shevchenko@xxxxxxxxx> wrote: > > > On Thu, Oct 29, 2020 at 7:17 PM Andy Shevchenko > > > <andy.shevchenko@xxxxxxxxx> wrote: > > > > On Thu, Oct 29, 2020 at 4:55 PM Ricardo Ribalda <ribalda@xxxxxxxxxx> wrote: > > > > > On Thu, Oct 29, 2020 at 3:45 PM Andy Shevchenko > > > > > <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote: > > > > > > On Wed, Oct 28, 2020 at 10:10:42PM +0100, Ricardo Ribalda wrote: > > > > > > > > ... > > > > > > > > > > ActiveLevel field is described in 19.6.55 GpioInt (GPIO Interrupt Connection > > > > > > Resource Descriptor Macro). > > > > > > > > > > > > > Without using the active_low, how can we describe a pin that is > > > > > > > active low and has to trigger an irq on both edges? > > > > > > > > > > > > This is nonsense. > > > > > > What does it mean? > > > > > > > > > > Let me try to explain myself again: > > > > > > > > > > I have a gpio pin that produces IRQs on both edges. so ActiveLevel is Both > > > > > > > > > > The problem is that the value of that pin is inverted: Low means 1 and > > > > > high means 0. > > > > > > > > > > How can I describe that the pin "is inverted" without using the _DSD field? > > > > > > > > "Both edges" and "inverted" or "polarity low" in one sentence make no sense. > > > > > > To be on the constructive side, I can *imagine* so badly designed > > > hardware that uses level and edge at the same time, but before I go to > > > conclusions, can you share relevant (pieces of) datasheet? > > > > The [1] is a real example of how GPIO is being used to detect changing > > of current level of the signal. > > Note, ACPI tables for that device have problems [2], but I guess you > > may get the idea. > > > This is exactly what I need to do. Get an IRQ whenever the value > changes. But the pin is "inverted" Yes. It's fine. The above is using GpioIo() resource where polarity is part of the _DSD (okay, the actual ACPI table doesn't have it, but you can do it). > This is the "schematic" : https://ibb.co/f8GMBbP . I want to pass to > userspace a "1" when the switch is closed and "0" when it is open. > > [1]: https://elixir.bootlin.com/linux/latest/source/drivers/extcon/extcon-intel-int3496.c#L138 > > [2]: https://elixir.bootlin.com/linux/latest/source/drivers/extcon/extcon-intel-int3496.c#L45 -- With Best Regards, Andy Shevchenko
