ARM: tegra: Correct polarity for Tegra114 PMIC interrupt

From: Jon Hunter <jonathanh@nvidia.com>

The ARM GIC only supports interrupts with either level-high or
rising-edge types for SPIs. The interrupt type for the Palmas PMIC used
for Tegra114 boards is specified as level-low which is invalid for the
GIC. This has gone undetected because until recently, failures to set
the interrupt type when the interrupts are mapped via firmware (such as
device-tree) have not been reported. Since commits 4b357daed698
("genirq: Look-up trigger type if not specified by caller") and
1e2a7d78499e ("irqdomain: Don't set type when mapping an IRQ"), failure
to set the interrupt type will cause the requesting of the interrupt to
fail and exposing incorrectly configured interrupts.

Please note that although the interrupt type was never being set for the
Palmas PMIC, it was still working fine, because the default type setting
for the interrupt, 'level-high', happen to match the correct type for
the interrupt.

Finally, it should be noted that the Palmas interrupt from the PMIC is
actually 'level-low', however, this interrupt signal is inverted by the
Tegra PMC and so the GIC actually sees a 'level-high' interrupt which is
what should be specified in the device-tree interrupt specifier.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
Hi ARM-SoC maintainers,

this is a fix required for v4.8, or else the PMIC won't work on various
Tegra114 boards.

Thanks,
Thierry

 arch/arm/boot/dts/tegra114-dalmore.dts | 2 +-
 arch/arm/boot/dts/tegra114-roth.dts    | 2 +-
 arch/arm/boot/dts/tegra114-tn7.dts     | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

On Wed, Aug 24, 2016 at 03:14:38PM +0200, Thierry Reding wrote:
> From: Jon Hunter <jonathanh@nvidia.com>
> 
> The ARM GIC only supports interrupts with either level-high or
> rising-edge types for SPIs. The interrupt type for the Palmas PMIC used
> for Tegra114 boards is specified as level-low which is invalid for the
> GIC. This has gone undetected because until recently, failures to set
> the interrupt type when the interrupts are mapped via firmware (such as
> device-tree) have not been reported. Since commits 4b357daed698
> ("genirq: Look-up trigger type if not specified by caller") and
> 1e2a7d78499e ("irqdomain: Don't set type when mapping an IRQ"), failure
> to set the interrupt type will cause the requesting of the interrupt to
> fail and exposing incorrectly configured interrupts.
> 
> Please note that although the interrupt type was never being set for the
> Palmas PMIC, it was still working fine, because the default type setting
> for the interrupt, 'level-high', happen to match the correct type for
> the interrupt.
> 
> Finally, it should be noted that the Palmas interrupt from the PMIC is
> actually 'level-low', however, this interrupt signal is inverted by the
> Tegra PMC and so the GIC actually sees a 'level-high' interrupt which is
> what should be specified in the device-tree interrupt specifier.
> 
> Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
> Hi ARM-SoC maintainers,
> 
> this is a fix required for v4.8, or else the PMIC won't work on various
> Tegra114 boards.

Applied to fixes.


Thanks,


-Olof

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