Re: [PATCH] drivers: tca8418: Change the interrupt type

From	Dmitry Torokhov <dmitry.torokhov@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] drivers: tca8418: Change the interrupt type
Date	2016-11-10 05:10 +0100
Message-ID	<sBOQx-om-5@gated-at.bofh.it> (permalink)
References	<sATpf-4qY-27@gated-at.bofh.it> <sBoCJ-8eR-1@gated-at.bofh.it> <sBw7f-4HJ-3@gated-at.bofh.it>
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Hi Maxime,

On Wed, Nov 09, 2016 at 09:02:35AM +0100, Maxime Ripard wrote:
> Hello Dmitry,
> 
> On Tue, Nov 08, 2016 at 04:04:00PM -0800, Dmitry Torokhov wrote:
> > On Mon, Nov 07, 2016 at 03:40:24PM +0100, Maxime Ripard wrote:
> > > The TCA8418 interrupt has a level trigger, not a edge one.
> > > 
> > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > 
> > Hmm, maybe we could rely on OF data for trigger type?
> 
> We might, even though the i2c core doesn't change the trigger type
> when it retrieves the interrupt from the DT.

i2c core itself does not, and should not, but irq code does:

of_irq_get() -> irq_create_of_mapping() -> irq_create_fwspec_mapping()
-> irqd_set_trigger_type().

> 
> However, I'm a bit worried about the other probing mechanims (ACPI,
> board files) that should be supported as well, and removing the
> trigger type from the flags might break those. There's no board files
> using it though in the tree, but I don't know about ACPI systems.

The driver is not enabled for ACPI systems, at least not in mainline.

By the way, this is what TCA8418 binding dochas to say:

"- interrupts: IRQ line number, should trigger on falling edge"

so it seems there was at least one system that needed falling edge and
not level interrupt.

Thanks.

-- 
Dmitry

Thread

[PATCH] drivers: tca8418: Change the interrupt type Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-11-07 15:50 +0100
  Re: [PATCH] drivers: tca8418: Change the interrupt type Dmitry Torokhov <dmitry.torokhov@gmail.com> - 2016-11-09 01:10 +0100
    Re: [PATCH] drivers: tca8418: Change the interrupt type Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-11-09 09:10 +0100
      Re: [PATCH] drivers: tca8418: Change the interrupt type Dmitry Torokhov <dmitry.torokhov@gmail.com> - 2016-11-10 05:10 +0100
        Re: [PATCH] drivers: tca8418: Change the interrupt type Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-11-10 10:20 +0100

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