Re: [PATCH v2 1/4] dt-bindings: dma: Add binding for Actions Semi Owl SoCs

[Manivannan Sadhasivam]

Hi Vinod,

On Tue, Jul 24, 2018 at 05:46:04PM +0530, Vinod wrote:
> Hi Mani,
> 
> Patch title should be dmaengine: ... Please always use the apt tags and
> one can find them using git log <subsystem>
> 

Did you mean, dt-bindings: dmaengine? If yes, then I will use it for the
future patches.

> On 23-07-18, 09:47, Manivannan Sadhasivam wrote:
> > Add devicetree binding for Actions Semi Owl SoCs DMA controller.
> 
> 
> It would help for review to describe the controller here
> 

Okay.

> > 
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > ---
> >  .../devicetree/bindings/dma/owl-dma.txt       | 46 +++++++++++++++++++
> >  1 file changed, 46 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/dma/owl-dma.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/dma/owl-dma.txt b/Documentation/devicetree/bindings/dma/owl-dma.txt
> > new file mode 100644
> > index 000000000000..dd6ce237b216
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/dma/owl-dma.txt
> > @@ -0,0 +1,46 @@
> > +* Actions Semi Owl SoCs DMA controller
> > +
> > +This binding follows the generic DMA bindings defined in dma.txt.
> > +
> > +Required properties:
> > +- compatible: Should be "actions,s900-dma".
> > +- reg: Should contain DMA registers location and length.
> > +- interrupts: Should contain 4 interrupts shared by all channel.
> > +- #dma-cells: Must be <1>. Used to represent the number of integer
> > +              cells in the dmas property of client device.
> > +- dma-channels: Physical channels supported.
> > +- dma-requests: Virtual channels supported.
> 
> not really, virtual channel is a software concepts. On the other hand
> you may have request lines in hw and you can describe that, if not skip
> this one
> 

Okay. Will change the property description to request signals.

Thanks,
Mani

> > +- clocks: Phandle and Specifier of the clock feeding the DMA controller.
> > +
> > +Example:
> > +
> > +Controller:
> > +                dma: dma-controller@e0260000 {
> > +                        compatible = "actions,s900-dma";
> > +                        reg = <0x0 0xe0260000 0x0 0x1000>;
> > +                        interrupts = <GIC_SPI 57 IRQ_TYPE_LEVEL_HIGH>,
> > +                                     <GIC_SPI 58 IRQ_TYPE_LEVEL_HIGH>,
> > +                                     <GIC_SPI 59 IRQ_TYPE_LEVEL_HIGH>,
> > +                                     <GIC_SPI 60 IRQ_TYPE_LEVEL_HIGH>;
> > +                        #dma-cells = <1>;
> > +                        dma-channels = <12>;
> > +                        dma-requests = <46>;
> > +                        clocks = <&clock CLK_DMAC>;
> > +                };
> > +
> > +Client:
> > +
> > +DMA clients connected to the Actions Semi Owl SoCs DMA controller must
> > +use the format described in the dma.txt file, using a two-cell specifier
> > +for each channel.
> > +
> > +The two cells in order are:
> > +1. A phandle pointing to the DMA controller.
> > +2. The channel id.
> > +
> > +uart5: serial@e012a000 {
> > +        ...
> > +        dma-names = "tx", "rx";
> > +        dmas = <&dma 26>, <&dma 27>;
> > +        ...
> > +};
> > -- 
> > 2.17.1
> 
> -- 
> ~Vinod