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Problem with interfacing SPI device with wandboard dual

Question asked by ARAVIND S on Jan 4, 2017
Latest reply on Jan 5, 2017 by igorpadykov

Hi,
I'm using imx6 wandboard dual tried to configure spi1,

made device-tree changes:

-----------------------------------------------
...
&iomuxc {
...
    ecspi1 {
         pinctrl_ecspi1_cs: ecspi1cs {
                         fsl,pins = <
                             MX6QDL_PAD_EIM_EB2__ECSPI1_SS0  0x80000000
                             >;
                     };
 pinctrl_ecspi1: ecspi1grp {
                      fsl,pins = <
                          MX6QDL_PAD_EIM_D17__ECSPI1_MISO 0x100b1
                          MX6QDL_PAD_EIM_D18__ECSPI1_MOSI 0x100b1
                          MX6QDL_PAD_EIM_D16__ECSPI1_SCLK 0x100b1
                          >;
                  };
    };
...

...
&ecspi1 {
    fsl,spi-num-chipselects = <1>;
    pinctrl-names = "default";
    pinctrl-0 = <&pinctrl_ecspi1 &pinctrl_ecspi1_cs>;
    status = "okay";
    spidev@0x01 {
        compatible = "linux,lcd-st7565";
        spi-max-frequency = <20000000>;
        reg = <0x0>;
        register-sel-gpio =<&gpio4 5 0>;
        reset-gpio =<&gpio7 13 0>;
        backlight-gpio =<&gpio3 26 0>;
        status = "okay";
    };
};
...
----------------------------------------------------------------

but while connecting the LCD to the SPI, its not working (lcd-st7565 driver for my LCD, which is working fine as i get all debug prints)on probing the SPI pins with oscilloscope confirmed data is coming but in some distorted manner (overshoot undershoot problem),

 

kernel version 3.14.28

oscilloscope probed  : data line and clock
can anyone please guide me what is the reason for such a behavior..??

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