iMX6Q,Use DMA to operate ssi

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iMX6Q,Use DMA to operate ssi

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hsl
Contributor I

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!

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igorpadykov
NXP Employee
NXP Employee

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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