Hi Rob, Thanks for the review... > -----Original Message----- > From: Rob Herring [mailto:robh@xxxxxxxxxx] > Sent: Thursday, April 14, 2016 8:34 PM > To: Appana Durga Kedareswara Rao <appanad@xxxxxxxxxx> > Cc: 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>; devicetree@xxxxxxxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > dmaengine@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v5 1/2] Documentation: DT: dma: Add Xilinx zynqmp dma > device tree binding documentation > > On Wed, Apr 13, 2016 at 10:46:48AM +0530, Kedareswara rao Appana wrote: > > Device-tree binding documentation for Xilinx zynqmp dma engine used in > > Zynq UltraScale+ MPSoC. > > > > Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xxxxxxxxxx> > > Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx> > > --- > > Changes in v5: > > - Use dma-coherent flag for coherent transfers as suggested by rob. > > - Removed unnecessary properties from binding doc as suggested by Rob. > > Changes in v4: > > - None > > Changes in v3: > > - None > > Changes in v2: > > - None. > > > > .../devicetree/bindings/dma/xilinx/zynqmp_dma.txt | 50 > ++++++++++++++++++++++ > > 1 file changed, 50 insertions(+) > > create mode 100644 > Documentation/devicetree/bindings/dma/xilinx/zynqmp_dma.txt > > > > diff --git a/Documentation/devicetree/bindings/dma/xilinx/zynqmp_dma.txt > b/Documentation/devicetree/bindings/dma/xilinx/zynqmp_dma.txt > > new file mode 100644 > > index 0000000..4ad0aea40 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/dma/xilinx/zynqmp_dma.txt > > @@ -0,0 +1,50 @@ > > +Xilinx ZynqMP DMA engine, it does support memory to memory transfers, > > +memory to device and device to memory transfers. It also has flow > > +control and rate control support for slave/peripheral dma access. > > + > > +Required properties: > > +- compatible : Should be "xlnx,zynqmp-dma-1.0" > > +- reg : Memory map for gdma/adma module access. > > +- interrupt-parent : Interrupt controller the interrupt is routed through > > +- interrupts : Should contain DMA channel interrupt. > > +- xlnx,bus-width : Axi buswidth in bits. Should contain 128 or 64 > > +- clock-names : List of input clocks "clk_main", "clk_apb" > > + (see clock bindings for details) > > + > > +Optional properties: > > +- 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,desc-axi-cache : AXI cache bits to be used for descriptor fetch > > +- xlnx,src-axi-cache : AXI cache bits to be used for data read > > +- xlnx,dst-axi-cache : AXI cache bits to be used for data write > > Shouldn't you be able to derive these values from whether dma-coherent > is set. To put it another way, allowing setting both allows for lots of > broken combinations. Ok will remove these properties and will set these cache bits only When dma-coherent is present in the driver. > > > +- xlnx,src-burst-len : AXI length for data read. Support only power of > > + 2 values. > > +- xlnx,dst-burst-len : AXI length for data write. Support only power of > > + 2 values. > > What unit? Seems to be beats from the example. I would suggest bytes > instead. Bytes only will fix in next version... > > > +- dma-coherent : Present if dma operations are coherent. > > + > > +Example: > > +++++++++ > > +fpd_dma_chan1: dma@FD500000 { > > lowercase address. Will fix in next version. > > > + compatible = "xlnx,zynqmp-dma-1.0"; > > + reg = <0x0 0xFD500000 0x1000>; > > + interrupt-parent = <&gic>; > > + interrupts = <0 117 4>; > > + clock-names = "clk_main", "clk_apb"; > > + xlnx,bus-width = <128>; > > + xlnx,include-sg; > > + xlnx,overfetch; > > + dma-coherent; > > + xlnx,ratectrl = <0>; > > + xlnx,src-issue = <16>; > > + xlnx,desc-axi-cache = <0xFF>; > > + xlnx,src-axi-cache = <0xFF>; > > + xlnx,dst-axi-cache = <0xFF>; > > Last I checked, AXI only has 4 cache bits. Hmm wrong example anyway will remove these properties in the next version... Regards, Kedar. > > > + xlnx,src-burst-len = <4>; > > + xlnx,dst-burst-len = <4>; > > +}; > > -- > > 2.1.2 > > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
