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

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@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Tanglei Han <hantanglei@huawei.com>
Cc: Zhuangluan Su <suzhuangluan@hisilicon.com>
Cc: Ryan Grachek <ryan@edited.us>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: dmaengine@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
v3: Renamed to hisi-dma-avail-chan
---
 Documentation/devicetree/bindings/dma/k3dma.txt | 3 +++
 1 file changed, 3 insertions(+)

On Thu, Jan 10, 2019 at 11:34 AM John Stultz <john.stultz@linaro.org> 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@kernel.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Tanglei Han <hantanglei@huawei.com>
> Cc: Zhuangluan Su <suzhuangluan@hisilicon.com>
> Cc: Ryan Grachek <ryan@edited.us>
> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> Cc: dmaengine@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
> 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

On Fri, Jan 11, 2019 at 1:58 PM Rob Herring <robh+dt@kernel.org> wrote:
>
> On Thu, Jan 10, 2019 at 11:34 AM John Stultz <john.stultz@linaro.org> 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@kernel.org>
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: Mark Rutland <mark.rutland@arm.com>
> > Cc: Tanglei Han <hantanglei@huawei.com>
> > Cc: Zhuangluan Su <suzhuangluan@hisilicon.com>
> > Cc: Ryan Grachek <ryan@edited.us>
> > Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > Cc: dmaengine@vger.kernel.org
> > Cc: devicetree@vger.kernel.org
> > Signed-off-by: John Stultz <john.stultz@linaro.org>
> > ---
> > 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

On Fri, Jan 11, 2019 at 12:04 PM Rob Herring <robh+dt@kernel.org> wrote:
>
> On Fri, Jan 11, 2019 at 1:58 PM Rob Herring <robh+dt@kernel.org> wrote:
> >
> > On Thu, Jan 10, 2019 at 11:34 AM John Stultz <john.stultz@linaro.org> 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@kernel.org>
> > > Cc: Rob Herring <robh+dt@kernel.org>
> > > Cc: Mark Rutland <mark.rutland@arm.com>
> > > Cc: Tanglei Han <hantanglei@huawei.com>
> > > Cc: Zhuangluan Su <suzhuangluan@hisilicon.com>
> > > Cc: Ryan Grachek <ryan@edited.us>
> > > Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > > Cc: dmaengine@vger.kernel.org
> > > Cc: devicetree@vger.kernel.org
> > > Signed-off-by: John Stultz <john.stultz@linaro.org>
> > > ---
> > > 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'.

Ok. I'll rework it for that then.

> 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.

Ok. I'll keep it in the driver for now unless otherwise directed.

Thanks so much for the review!
-john