Hi, On 11 May 2012 13:33, Josh Wu <josh.wu@xxxxxxxxx> wrote: > Hi, Javier > > > On 5/11/2012 5:13 PM, javier Martin wrote: > >> Hi all, >> let's take a chip which presents a similar issue like the pca953x [1]. >> This chip has an IRQ line that is meant to be connected to a SoC input >> like the qt1070. >> >> The flags that are used for pca953x are: (IRQF_TRIGGER_LOW | IRQF_ONESHOT) >> >> Can't we do the same for qt1070? > > > I did a simple test in my board in 2.6.39, This flag doesn't work. But > IRQF_TRIGGER_FALLING works fine. > So the question is what is different between this flag with > IRQF_TRIGGER_FALLING? I don't know but IRQF_TRIGGER_FALLING works for me too. >> And even more important, can you give me an example of an architecture >> in mainline which cannot support these irq flags and still be able to >> detect a change from high to low in a GPIO as qt1070 requires? > > > For now, AT91SAM9M10 can only detect GPIO input change, it cannot tell is > falling or rising. So in theory it cannot support falling flags. > The strange thing is, currently we use IRQF_TRIGGER_NONE in 2.6.39 kernel > for both AT91SAM9M10 and 9X5 chips, and they all work fine. So I need check > the code of GPIO part. > > >> >> Moreover, if you try a grep for IRQ_TRIGGER_NONE in the kernel tree >> you won't find any driver doing this strange thing. >> >> Do you agree at least that we must change IRQ_TRIGGER_NONE flag into a >> more sensible choice? > > > Yes. I agreed. > >> >> Regards. >> >> [1] http://lxr.linux.no/#linux+v3.3.4/drivers/gpio/gpio-pca953x.c#L495 -- Javier Martin Vista Silicon S.L. CDTUC - FASE C - Oficina S-345 Avda de los Castros s/n 39005- Santander. Cantabria. Spain +34 942 25 32 60 www.vista-silicon.com -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
