pinctrl: qcom: Handle broken/missing PDC dual edge IRQs on sc7180
Depending on how you look at it, you can either say that: a) There is a PDC hardware issue (with the specific IP rev that exists on sc7180) that causes the PDC not to work properly when configured to handle dual edges. b) The dual edge feature of the PDC hardware was only added in later HW revisions and thus isn't in all hardware. Regardless of how you look at it, let's work around the lack of dual edge support by only ever letting our parent see requests for single edge interrupts on affected hardware. NOTE: it's possible that a driver requesting a dual edge interrupt might get several edges coalesced into a single IRQ. For instance if a line starts low and then goes high and low again, the driver that requested the IRQ is not guaranteed to be called twice. However, it is guaranteed that once the driver's interrupt handler starts running its first instruction that any new edges coming in will cause the interrupt to fire again. This is relatively commonplace for dual-edge gpio interrupts (many gpio controllers require software to emulate dual edge with single edge) so client drivers should be setup to handle it. Fixes: e35a6ae0 ("pinctrl/msm: Setup GPIO chip in hierarchy") Signed-off-by:Douglas Anderson <dianders@chromium.org> Reviewed-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200714080254.v3.1.Ie0d730120b232a86a4eac1e2909bcbec844d1766@changeid Signed-off-by:
Linus Walleij <linus.walleij@linaro.org>
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