why imx8qxp spi chip select have overturn after 8bit transfer?

[caoyk]

Now wo use lpspi0 to  connect spi dev.

dts :

&lpspi0 {
#address-cells = <1>;
#size-cells = <0>;
fsl,spi-num-chipselects = <1>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_lpspi0>;

status = "okay";

    fm1388_spi@0 {
    compatible = "fm1388_spi";
    reg = <0>;
    spi-max-frequency = <2000000>;
    //spi-cpha;
    //spi-cpol;
    //poll_mode = <0>;
    //type = <0>;
    //enable_dma = <1>;
    };

};

Then lpspi0 is work fine but spi dev have no return data.

After it we use  Logic analyzer to capture spi waveform. 

Result is in Attachment.

We can see spi chip select have overturn after 8bit transfer. Maybe it cause error.

How to change chip select be high after all date  transfered, looking forward to a reply .

[VijayAnnamalaisamy]

Hi all,

I am also facing the same issue with iMX8 QXP. Using LPSPI0 with SPIDEV. Observing that Chip select signal comes back to HIGH after 8 bit transfer. Because of this, the response from the SPI slave was not received.

Please let me know if there is a solution to this problem.

Thanks in advance,

Vijay