[RFC 3/5] powerpc/mpic: Add support for non-contiguous irq ranges

[Rob Herring]

On Fri, Jul 27, 2018 at 03:17:59PM +0530, Bharat Bhushan wrote:
> Freescale MPIC h/w may not support all interrupt sources reported
> by hardware, "last-interrupt-source" or platform. On these platforms
> a misconfigured device tree that assigns one of the reserved
> interrupts leaves a non-functioning system without warning.

There are lots of ways to misconfigure DTs. I don't think this is 
special and needs a property. We've had some interrupt mask or valid 
properties in the past, but generally don't accept those.

> 
> This patch adds "supported-irq-ranges" property in device tree to
> provide the range of supported source of interrupts. If a reserved
> interrupt used then it will not be programming h/w, which it does
> currently, and through warning.
> 
> Signed-off-by: Bharat Bhushan <Bharat.Bhushan at nxp.com>
> ---
>  .../devicetree/bindings/powerpc/fsl/mpic.txt       |   8 ++
>  arch/powerpc/include/asm/mpic.h                    |   9 ++
>  arch/powerpc/sysdev/mpic.c                         | 113 +++++++++++++++++++--
>  3 files changed, 121 insertions(+), 9 deletions(-)