IMX6UL-ADC issue

[anshulkhare]

Hello All,

I need my ADC driver working in the imx6ul board with 9 channels.

I have modified dtsi files as shown below:

adc1: adc@02198000 {
compatible = "fsl,imx6ul-adc", "fsl,vf610-adc";
reg = <0x02198000 0x4000>;
interrupts = <GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&clks IMX6UL_CLK_ADC1>;
num-channels = <9>;

clock-names = "adc";
status = "disabled";
};

pinctrl_adc1: adc1grp {

fsl,pin = <
MX6UL_PAD_GPIO1_IO00__GPIO1_IO00 0xb0
MX6UL_PAD_GPIO1_IO01__GPIO1_IO01 0xb0
.
.. .
.
MX6UL_PAD_GPIO1_IO07__GPIO1_IO07 0xb0
MX6UL_PAD_GPIO1_IO08__GPIO1_IO08 0xb0
>;

};

&adc1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_adc1>;
vref-supply = <&reg_mba6ul_3v3>;
status = "okay";
};

but i am getting the voltage as 4095 all the times when i am varying the input volatges
and in boot logs i am getting below print for adc.

imx6ul-pinctrl 20e0000.iomuxc: no fsl,pins property in node /soc/aips-bus@02000000/iomuxc@020e0000/imx6ul-mba6ul/adc1grp

So, I tried adding one of the pin(GPIO1_IO01) configuration under "lcdifgrp" and the voltage was varying for the particular channel.
Similary, we added all the pins under "lcdifgrp".
All channel voltages except one(GPIO4_IO04) was varying.
Could someone tell me what might be the issue?

Kindly help to resolve this .

Regards,

Anshul

[igorpadykov]

Hi Anshul

one can check if GPIO4_IO04 used in uboot and look at issue described on
iMX6UL adc calibration fails 

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[anshulkhare]

Hello Igor,

Thank you for the reply,
I have checked GPIO1_IO04 is not using in uboot,
but i am not able to vary the voltage value on the pin.

what could be be the issue??
kindly help to resolve this .

Regards,
Anshul

[igorpadykov]

Hi Anshul

to check if this is not hardware issue, please try to reproduce it

on i.MX6UL EVK reference board.

Best regards
igor