imx6ul ecspi generating signal cs

[2669889282]

hi:

There is currently a peripheral spi regmap API used for read and write operations,  in ecspi3 bus connection,The cs pin is configured as required cs function which automatically generates a CS signal, not configured GPIO function to generate a CS signal manually .

dts configuration is as follows:
                pinctrl_ecspi3: ecspi3grp {
                        fsl,pins = <
                                MX6UL_PAD_UART2_RTS_B__ECSPI3_MISO        0x100b1  /* MISO*/
                                MX6UL_PAD_UART2_CTS_B__ECSPI3_MOSI        0x100b1  /* MOSI*/
                                MX6UL_PAD_UART2_RX_DATA__ECSPI3_SCLK      0x100b1  /* CLK*/
                                MX6UL_PAD_UART2_TX_DATA__ECSPI3_SS0       0x100b1  /* CS*/
                        >;
                };

However, the automatic generation CS / SS signals are as follows:

But my spi peripherals required CS / SS signals, as follows

How do I modify the kernel and dts?
linux kernel version is linux-4.9.88

[igorpadykov]

Hi lincheng

one can try below patch :

[v4,1/3] spi: imx: GPIO chip select DT property should not be required - Patchwork 

Best regards
igor
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[2669889282]

hi igorpadykov：

patch does not solve my problem

SPI requires native chip select lines which automatically generates a CS signal ,instead of using the GPIO  generates  signal CS manually

ths

[MicMoba]

Hi lincheng,

did you find a solution for your problem? I have the same issue. I need that the CS stays low during a transmission of one command byte and receive three data bytes.

Currently I solved this by using the CS manually as GPIO but this is not very satisfy.