Cory Maccarrone <[email protected]> writes: > Some chips, namely any OMAP1 chips using METHOD_MPUIO, > OMAP15xx and OMAP7xx, cannot be setup to respond to on-chip GPIO > interrupts in both rising and falling edge directions -- they can > only respond to one direction or the other, depending on how the > ICR is configured. > > Additionally, current code forces rising edge detection if both > flags are specified: > > if (trigger & IRQ_TYPE_EDGE_RISING) > l |= 1 << gpio; > else if (trigger & IRQ_TYPE_EDGE_FALLING) > l &= ~(1 << gpio); > else > goto bad; > > This change implements a toggle function that will modify the ICR > to flip the direction of interrupt for IRQs that are requested with > both rising and falling flags. The toggle function is not called > for chips and GPIOs it does not apply to through the use of a flip_mask > that's added on a per-bank basis. The mask is only set for those > GPIOs where a toggle is necessary. Edge detection starts out the > same as above with FALLING mode first. > > The toggle happens on EACH interrupt; without it, we have the > following sequence of actions on GPIO transition: > > ICR GPIO Result > 0x1 0 -> 1 (rising) Interrupt > 0x1 1 -> 0 (falling) No interrupt > > (set ICR to 0x0 manually) > 0x0 0 -> 1 (rising) No interrupt > 0x0 1 -> 0 (falling) Interrupt > > That is, with the ICR set to 1 for a gpio, only rising edge interrupts > are caught, and with it set to 0, only falling edge interrupts are > caught. If we add in the toggle, we get this: > > ICR GPIO Result > 0x1 0 -> 1 (rising) Interrupt (ICR set to 0x0) > 0x0 1 -> 0 (falling) Interrupt (ICR set to 0x1) > 0x1 0 -> 1 ... > > so, both rising and falling are caught, per the request for both > (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING). > > Signed-off-by: Cory Maccarrone <[email protected]>
This version looks good. Acked-by: Kevin Hilman <[email protected]> Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
