RE: [PATCH v7 1/2] Documentation: DT: dma: Add Xilinx zynqmp dma device tree binding documentation

[Appana Durga Kedareswara Rao]

Hi Lars,

> -----Original Message-----
> From: Lars-Peter Clausen [mailto:lars@xxxxxxxxxx]
> Sent: Wednesday, April 27, 2016 12:42 PM
> To: Appana Durga Kedareswara Rao <appanad@xxxxxxxxxx>;
> robh+dt@xxxxxxxxxx; pawel.moll@xxxxxxx; mark.rutland@xxxxxxx;
> ijc+devicetree@xxxxxxxxxxxxxx; galak@xxxxxxxxxxxxxx; Michal Simek
> <michals@xxxxxxxxxx>; Soren Brinkmann <sorenb@xxxxxxxxxx>;
> vinod.koul@xxxxxxxxx; dan.j.williams@xxxxxxxxx; Appana Durga Kedareswara
> Rao <appanad@xxxxxxxxxx>; moritz.fischer@xxxxxxxxx;
> laurent.pinchart@xxxxxxxxxxxxxxxx; luis@xxxxxxxxxxxxxxxxx; Anirudha
> Sarangi <anirudh@xxxxxxxxxx>; Punnaiah Choudary Kalluri
> <punnaia@xxxxxxxxxx>
> Cc: devicetree@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; dmaengine@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v7 1/2] Documentation: DT: dma: Add Xilinx zynqmp dma
> device tree binding documentation
> 
> On 04/27/2016 09:05 AM, Kedareswara rao Appana wrote:
> [...]
> > +- xlnx,include-sg	: Indicates the controller to operate in simple or
> > +			  scatter gather dma mode
> > +- xlnx,ratectrl		: Scheduling interval in terms of clock cycles for
> > +			  source AXI transaction
> > +- xlnx,overfetch	: Tells whether the channel is allowed to over
> > +			  fetch the data
> > +- xlnx,src-issue	: Number of AXI outstanding transactions on source
> side
> > +- xlnx,src-burst-len	: AXI length for data read. Support only power of
> > +			  2 byte values.
> > +- xlnx,dst-burst-len	: AXI length for data write. Support only power of
> 
> These are all software runtime configuration parameters that you'd want to
> change at runtime depending on which peripheral you are targeting with a
> specific DMA transfer. These really do not belong into the devicetree.

You mean to have a separate config structure in the driver and handle the above parameters
Through that structure???

I understand that above will work for slave dma transfer types what about memory to memory
Transfers where we don't have provision to the use this parameters...

Regards,
Kedar.