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ESCPI1-SPIDEV0-CLK_CS_MOSI_MISO pin voltage issue "Linux 3.14.52"

Question asked by Vishal Gupta on Jul 4, 2016
Latest reply on May 17, 2018 by sharddha bhalerao

Hi IMx Friends,

 

I was trying to interface a transceiver module to the imx6 dual lite using the SPI protocol.

 

Here with the Pin mux Details:

From IOMUX Tool :

 

 

 

From my  imxqdl_my.dtsi file :

 

&ecspi1 {

        fsl,spi-num-chipselects = <1>;

        cs-gpios = <&gpio5 25 GPIO_ACTIVE_HIGH>;

        pinctrl-names = "default";

        pinctrl-0 = <&pinctrl_ecspi1>;

        status = "okay";

 

        spidev@0 {

               compatible = "spidev";

               spi-max-frequency = <100000>;

               reg = <0>;

        };

};

 

 

pinctrl_ecspi1: ecspi1grp {

                        fsl,pins = <

                                MX6QDL_PAD_CSI0_DAT6__ECSPI1_MISO       0x100b1

                                MX6QDL_PAD_CSI0_DAT5__ECSPI1_MOSI       0x100b1

                                MX6QDL_PAD_CSI0_DAT4__ECSPI1_SCLK       0x100b1

                                /*MX6QDL_PAD_CSI0_DAT7__ECSPI1_SS0      0x100b1*/

                                MX6QDL_PAD_CSI0_DAT7__GPIO5_IO25        0x000b1

                        >;

                };

 

 

Note: The imx6dl works at 3.3volt and the transceiver works at 1.8 volts.

 

With the above setting when i run my SPI test application, here are the probe results of the SPI_MOSI , SPI_MISO, SPI_CLK , SPI_CS as attached below .

 

The problem is :

ECSPI_SS0 chip select never pulls down( its stays at 1.8 volts as shown in the attached SPI_CS figure) when the IMx6 assert the MOSI and MISO lines.

I only see my data of ECSPI_MOSI from imx6 to transceiver coming as shown in the SPI_MOSI figure.

I only see ECSPI_MISO line goes from 0 to 0.2 volt .

I only See ECSPI_SCLK clock only comes when i run the application that to the amplitude of the signal goes up to 0.4 volts .

 

Can anyone please guide me how to make my SPI Communication block working between iMx6dl to transceiver  and drive the SPI pins?

 

Thanks,

Vishal

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