ARM: OMAP5+: Fix inverted nirq pin interrupts with irq_set_type

ARM: OMAP5+: Fix inverted nirq pin interrupts with irq_set_type

commit d0243693fbf6fbd48b4efb2ba7210765983b03e3 upstream.

Commit 83a86fbb5b56 ("irqchip/gic: Loudly complain about the use of
IRQ_TYPE_NONE") started warning about incorrect dts usage for irqs.
ARM GIC only supports active-high interrupts for SPI (Shared Peripheral
Interrupts), and the Palmas PMIC by default is active-low.

Palmas PMIC allows changing the interrupt polarity using register
PALMAS_POLARITY_CTRL_INT_POLARITY, but configuring sys_nirq1 with
a pull-down and setting PALMAS_POLARITY_CTRL_INT_POLARITY made the
Palmas RTC interrupts stop working. This can be easily tested with
kernel tools rtctest.c.

Turns out the SoC inverts the sys_nirq pins for GIC as they do not go
through a peripheral device but go directly to the MPUSS wakeupgen.
I've verified this by muxing the interrupt line temporarily to gpio_wk16
instead of sys_nirq1. with a gpio, the interrupt works fine both
active-low and active-high with the SoC internal pull configured and
palmas polarity configured. But as sys_nirq1, the interrupt only works
when configured ACTIVE_LOW for palmas, and ACTIVE_HIGH for GIC.

Note that there was a similar issue earlier with tegra114 and palmas
interrupt polarity that got fixed by commit df545d1cd01a ("mfd: palmas:
Provide irq flags through DT/platform data"). However, the difference
between omap5 and tegra114 is that tegra inverts the palmas interrupt
twice, once when entering tegra PMC, and again when exiting tegra PMC
to GIC.

Let's fix the issue by adding a custom wakeupgen_irq_set_type() for
wakeupgen and invert any interrupts with wrong polarity. Let's also
warn about any non-sysnirq pins using wrong polarity. Note that we
also need to update the dts for the level as IRQ_TYPE_NONE never
has irq_set_type() called, and let's add some comments and use proper
pin nameing to avoid more confusion later on.

Cc: Belisko Marek <marek.belisko@gmail.com>
Cc: Dmitry Lifshitz <lifshitz@compulab.co.il>
Cc: "Dr. H. Nikolaus Schaller" <hns@goldelico.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: stable@vger.kernel.org # v4.17+
Reported-by: Belisko Marek <marek.belisko@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>