Re: [PATCH 1/2] dt-bindings: dmaengine: Add SpacemiT K1 PDMA request numbers

On Tue, Jun 09, 2026 at 02:55:59PM -0400, Guodong Xu wrote:
> Hi, Conor
> 
> On 2026-06-08 18:33, Conor Dooley wrote:
> > On Sun, Jun 07, 2026 at 01:41:30PM -0400, Guodong Xu wrote:
> > > Add a dt-bindings header that gives symbolic names to the SpacemiT K1
> > > PDMA request lines of the non-secure peripherals. Device trees can use
> > > these K1_PDMA_* macros instead of magic numbers.
> > > 
> > > Point the spacemit,k1-pdma binding's #dma-cells description at the new
> > > header.
> > > 
> > > Signed-off-by: Guodong Xu <[email protected]>
> > > ---
> > >  .../devicetree/bindings/dma/spacemit,k1-pdma.yaml  |  4 +-
> > >  include/dt-bindings/dma/spacemit,k1-pdma.h         | 56 ++++++++++++++++++++++
> > >  2 files changed, 59 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml b/Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml
> > > index ec06235baf5ca..0d4ac9849e27b 100644
> > > --- a/Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml
> > > +++ b/Documentation/devicetree/bindings/dma/spacemit,k1-pdma.yaml
> > > @@ -35,7 +35,9 @@ properties:
> > >    '#dma-cells':
> > >      const: 1
> > >      description:
> > > -      The DMA request number for the peripheral device.
> > > +      The single cell is the DMA request number for the peripheral device.
> > > +      See <dt-bindings/dma/spacemit,k1-pdma.h> for the list of valid request
> > > +      numbers.
> > > 
> > >  required:
> > >    - compatible
> > > diff --git a/include/dt-bindings/dma/spacemit,k1-pdma.h b/include/dt-bindings/dma/spacemit,k1-pdma.h
> > 
> > Why does this need to be in a binding when there is no use of this in
> > the driver? May as well be a header, particularly if these are numbers
> 
> Thanks for the review. You are correct that these are not referenced in the
> driver. My change to k1-pdma.yaml should be dropped.
> 
> > with a set meaning that are lifted from the TRM, rather than made up
> > numbers to make a driver work. The former seems likely, given you're
> > indexing from 3 not 0.
> 
> Yes, it is defined in the K1 manual [1], see 9.4.3 DMA Connectivity &
> Assignments
> 
> Link: https://www.spacemit.com/community/document/info?lang=en&nodepath=hardware/key_stone/k1/k1_docs/k1_usermanual/9.Top_System.md [1]
> 
> I will fix that in v2.

Just in case I wasn't clear (and I think I wasn't), when I said "may as
well be a header" I meant a header in arch/riscv/boot/dts/spacemit.

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