Re: [PATCH 2/8 v3] Documentation: bindings: k3dma: Add binding for hisi-dma-avail-chan

From: Rob Herring
Date: Fri Jan 11 2019 - 15:04:53 EST


On Fri, Jan 11, 2019 at 1:58 PM Rob Herring <robh+dt@xxxxxxxxxx> wrote:
>
> On Thu, Jan 10, 2019 at 11:34 AM John Stultz <john.stultz@xxxxxxxxxx> wrote:
> >
> > Some dma channels can be reserved for secure mode or other
> > hardware on the SoC, so provide a binding for a bitmask
> > listing the available channels for the kernel to use.
> >
> > Cc: Vinod Koul <vkoul@xxxxxxxxxx>
> > Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> > Cc: Mark Rutland <mark.rutland@xxxxxxx>
> > Cc: Tanglei Han <hantanglei@xxxxxxxxxx>
> > Cc: Zhuangluan Su <suzhuangluan@xxxxxxxxxxxxx>
> > Cc: Ryan Grachek <ryan@xxxxxxxxx>
> > Cc: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > Cc: dmaengine@xxxxxxxxxxxxxxx
> > Cc: devicetree@xxxxxxxxxxxxxxx
> > Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
> > ---
> > v3: Renamed to hisi-dma-avail-chan
> > ---
> > Documentation/devicetree/bindings/dma/k3dma.txt | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/dma/k3dma.txt b/Documentation/devicetree/bindings/dma/k3dma.txt
> > index 10a2f15..38825d4 100644
> > --- a/Documentation/devicetree/bindings/dma/k3dma.txt
> > +++ b/Documentation/devicetree/bindings/dma/k3dma.txt
> > @@ -14,6 +14,9 @@ Required properties:
> > have specific request line
> > - clocks: clock required
> >
> > +Optional properties:
> > +- hisi-dma-avail-chan: Bitmask of available physical channels
>
> Not quite right. Should be: hisilicon,dma-avail-chan

Actually, we already have the same case elsewhere with
'brcm,dma-channel-mask'. Maybe there are others. So make the property
common (i.e. documented in dma.txt) and called 'dma-channel-mask'.

Whether or not the dmaengine handles this or not is irrelevant to
whether the binding is common or not. I have no say over OS design
decisions.

Rob