AnsweredAssumed Answered

we'd like use 16bit width DMA,but devicetree and driver is not supported

Question asked by sensarliar on Jul 14, 2016
Latest reply on Jul 15, 2016 by larsc

we'd like use 16bit width DMA instead of 64bit,but devicetree and driver is not supported.

I have modified  adi,source-bus-width = <64>; to  adi,source-bus-width = <16>; in zynq-picozed-sdr2.dtsi file.

but it seems make nonsense, as we received data that DMA runs in 64bit bus-width.

and we looked into the code in dma-axi-dmac.c.

it seems that the "dma_dev->src_addr_widths" did nothing in dmac driver.

it seems DMA Controller (axi_dmac) of  FPGA code fixed the transfer bus width to 64bit, is it true?

 

 

 

    rx_dma: dma@7c400000 {
   compatible = "adi,axi-dmac-1.00.a";
   reg = <0x7c400000 0x10000>;
   #dma-cells = <1>;
   interrupts = <0 57 0>;
   clocks = <&clkc 16>;

 

   dma-channel {
   adi,source-bus-width = <16>;
   adi,destination-bus-width = <16>;
   adi,type = <0>;
   };

Outcomes