Re: [PATCH V3 22/26] dt-bindings: interrupt-controller: C-SKY SMP intc

From: Arnd Bergmann
Date: Thu Sep 06 2018 - 09:03:36 EST


On Thu, Sep 6, 2018 at 4:23 AM Guo Ren <ren_guo@xxxxxxxxx> wrote:
> On Wed, Sep 05, 2018 at 07:45:12PM -0500, Rob Herring wrote:
> > On Wed, Sep 5, 2018 at 7:09 AM Guo Ren <ren_guo@xxxxxxxxx> wrote:
> > > +
> > > +C-SKY Multi-processors Interrupt Controller is designed for ck807/ck810/ck860
> > > +SMP soc, and it also could be used in non-SMP system.
> >
> > How is it accessed? No mmio registers?
> Mmio reg base is got from cpu-coprocessor register and I'll detail
> it here in next version patch.
>
> csky_mpintc_init(struct device_node *node, struct device_node *parent)
> {
> ...
> INTCG_base = ioremap(mfcr("cr<31, 14>"), INTC_SIZE);

It that reliable? I remember a similar situation with some registers on ARM
that are usually identified through a special CPU register, but in some
cases the SoC integrator put the wrong address in there, so we need to
look up the address in DT anyway.

Arnd