topic Re: iMX6Q DMA operating in i.MX Processors

iMX6Q，Use DMA to operate ssi

hsl — Wed, 05 Dec 2018 09:36:08 GMT

Hello everyone：

I am having a problem now, that is：

Want to use DMA to move data from the ssi register into memory，how to operate?
I hope to get some inspiration.

Set ssi like this in my device tree:

ssi2: ssi@0202c000 {
compatible = "fsl,imx6q-ssi","fsl,imx21-ssi";
reg = <0x0202c000 0x4000>;
interrupts = <0 47 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&clks IMX6QDL_CLK_SSI2_IPG>,
<&clks IMX6QDL_CLK_SSI2>;
clock-names = "ipg", "baud";
dmas = <&sdma 41 1 0>,
<&sdma 42 1 0>;
dma-names = "rx", "tx";
fsl,fifo-depth = <15>;
fsl,ssi-dma-events = <42 41>;
status = "disabled";
};

Thank you very much!

Re: iMX6Q DMA operating

igorpadykov — Wed, 05 Dec 2018 10:15:22 GMT

Hi H

according to sect.3.7 Smart Direct Memory Access (SDMA) API attached

Linux Manual sdma is used for some audio modules like ssi, esai,spdif.

One can test it with nxp linux from:

https://source.codeaurora.org/external/imx/linux-imx/tree/?h=imx_4.9.88_2.0.0_ga

Best regards
igor
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