On Mon, Aug 24, 2015 at 7:17 PM, Lars-Peter Clausen <lars@xxxxxxxxxx> wrote: > On 08/06/2015 05:19 AM, Punnaiah Choudary Kalluri wrote: > [...] >> +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-cohrnt: Tells whether the AXI transactions generated for the >> + descriptor read are marked Non-coherent >> +- xlnx,src-axi-cohrnt: Tells whether the AXI transactions generated for the >> + source descriptor payload are marked Non-coherent >> +- xlnx,dst-axi-cohrnt: Tells whether the AXI transactions generated for the >> + dst descriptor payload are marked Non-coherent >> +- xlnx,desc-axi-qos: AXI QOS bits to be used for descriptor fetch >> +- xlnx,src-axi-qos: AXI QOS bits to be used for data read >> +- xlnx,dst-axi-qos: AXI QOS bits to be used for data write >> +- xlnx,desc-axi-cache: AXI cache bits to be used for descriptor fetch. >> +- xlnx,desc-axi-cache: AXI cache bits to be used for data read >> +- xlnx,desc-axi-cache: AXI cache bits to be used for data write >> +- xlnx,src-burst-len: AXI length for data read. Support only power of 2 values >> + i.e 1,2,4,8 and 16 >> +- xlnx,dst-burst-len: AXI length for data write. Support only power of 2 values >> + i.e 1,2,4,8 and 16 > > None of these really belong into the devicetree. This is all runtime > configuration data. This is a general purpose dma and provides more flexibility to the user for configuring the descriptor, data and bus parameters. one way is as you said these parameters can be configured at runtime but i didn't find a way configuring the channel at runtime for mem to mem transfers. I have checked the device_config function description and it is strictly meant for slave operations only. So, i didn't see anything wrong having these parameter values from the device tree as these all are hw parameters. Regards, Punnaiah > > - Lars -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
