Messages in this thread | | | Date | Tue, 27 Nov 2012 08:40:07 +0000 | From | Lee Jones <> | Subject | Re: [PATCH V3 3/3] mfd: stmpe: Update DT support in stmpe driver |
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On Tue, 27 Nov 2012, Viresh Kumar wrote:
> On 27 November 2012 08:10, Viresh Kumar <viresh.kumar@linaro.org> wrote: > > On 27 November 2012 00:10, Grant Likely <grant.likely@secretlab.ca> wrote: > >> It would actually be good to ask the interrupt controller driver what > >> kind of interrupt signal it expects for a given interrupt line. That > >> should also solve the problem and I think it would be more useful to > >> other devices. Can you investigate whether or not > >> irqd_get_trigger_type() returns the information you need? > > > > That's a pretty cool function to use. :) > > > > Will check it out :) > > I was thinking about this logic in my earlier mail, don't know what stopped me > from thinking it is wrong. :( > > Problem is with invert polarity, which the interrupt controller is not aware of. > For example, suppose interrupt controller needs Rising edge interrupt, but > the board has inverted the line between stmpe and IC. So, we will get > Rising high from the routine you mentioned, but we need to generate > opposite of that to make it rising high.
Surely that would be a hardware design error/quirk?
Can you give an example where this has happened?
> And so interrupt polarity field is still required.
-- Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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