Re: [PATCH 1/2] RISC-V: Add DT documentation for SiFive L2 Cache Controller

[Sudeep Holla]

On Fri, Apr 26, 2019 at 11:20:17AM +0530, Yash Shah wrote:
> On Thu, Apr 25, 2019 at 3:43 PM Sudeep Holla <sudeep.holla@xxxxxxx> wrote:
> >
> > On Thu, Apr 25, 2019 at 11:24:55AM +0530, Yash Shah wrote:
> > > Add device tree bindings for SiFive FU540 L2 cache controller driver
> > >
> > > Signed-off-by: Yash Shah <yash.shah@xxxxxxxxxx>
> > > ---
> > >  .../devicetree/bindings/riscv/sifive-l2-cache.txt  | 53 ++++++++++++++++++++++
> > >  1 file changed, 53 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/riscv/sifive-l2-cache.txt
> > >
> > > diff --git a/Documentation/devicetree/bindings/riscv/sifive-l2-cache.txt b/Documentation/devicetree/bindings/riscv/sifive-l2-cache.txt
> > > new file mode 100644
> > > index 0000000..15132e2
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/riscv/sifive-l2-cache.txt
> > > @@ -0,0 +1,53 @@
> > > +SiFive L2 Cache Controller
> > > +--------------------------
> > > +The SiFive Level 2 Cache Controller is used to provide access to fast copies
> > > +of memory for masters in a Core Complex. The Level 2 Cache Controller also
> > > +acts as directory-based coherency manager.
> > > +
> > > +Required Properties:
> > > +--------------------
> > > +- compatible: Should be "sifive,fu540-c000-ccache"
> > > +
> > > +- cache-block-size: Specifies the block size in bytes of the cache
> > > +
> > > +- cache-level: Should be set to 2 for a level 2 cache
> > > +
> > > +- cache-sets: Specifies the number of associativity sets of the cache
> > > +
> > > +- cache-size: Specifies the size in bytes of the cache
> > > +
> > > +- cache-unified: Specifies the cache is a unified cache
> > > +
> > > +- interrupt-parent: Must be core interrupt controller
> > > +
> > > +- interrupts: Must contain 3 entries (DirError, DataError and DataFail signals)
> > > +
> > > +- reg: Physical base address and size of L2 cache controller registers map
> > > +
> > > +- reg-names: Should be "control"
> > > +
> >
> > It would be good if you mark the properties that are present in DT
> > specification and those that are added for sifive,fu540-c000-ccache
> 
> I believe there isn't any property which is added explicitly for
> sifive,fu540-c000-ccache.
> 

reg and interrupts are generally optional for normal cache and may be
required for cache controller like this. DT specification[1] covers
only caches and not cache controllers.

--
Regards,
Sudeep

[1] https://github.com/devicetree-org/devicetree-specification/releases/download/v0.2/devicetree-specification-v0.2.pdf