Re: [PATCH v2 2/2] irqchip: irq-qcom-mpm: Support passing a slice of SRAM as reg space

From: Shawn Guo
Date: Thu Apr 06 2023 - 00:08:34 EST


On Wed, Apr 05, 2023 at 12:48:35PM +0200, Konrad Dybcio wrote:
> The MPM hardware is accessible to us from the ARM CPUs through a shared
> memory region (RPM MSG RAM) that's also concurrently accessed by other
> kinds of cores on the system (like modem, ADSP etc.). Modeling this
> relation in a (somewhat) sane manner in the device tree basically
> requires us to either present the MPM as a child of said memory region
> (which makes little sense, as a mapped memory carveout is not a bus),
> define nodes which bleed their register spaces into one another, or
> passing their slice of the MSG RAM through some kind of a property.
>
> Go with the third option and add a way to map a region passed through
> the "qcom,rpm-msg-ram" property as our register space.
>
> The current way of using 'reg' is preserved for ABI reasons.
>
> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>

Acked-by: Shawn Guo <shawn.guo@xxxxxxxxxx>