Platform:iMX8QXP
Build enviroment:yocto
question:config ADC_IN0~ADC_IN5 as ADC channel,but the function is abnormal.
1.confirm CONFIG_IMX8QXP_ADC=y in arch/arm64/configs/defconfig;
2.add dts info in fsl-imx8qxp-ctx0800-rohs.dtsi file as followings:
&iomuxc {
[...]
pinctrl_adc0: adc0grp {
fsl,pins = <
SC_P_ADC_IN0_ADMA_ADC_IN0 0xc0000060
SC_P_ADC_IN1_ADMA_ADC_IN1 0xc0000060
SC_P_ADC_IN2_ADMA_ADC_IN2 0xc0000060
SC_P_ADC_IN3_ADMA_ADC_IN3 0xc0000060
SC_P_ADC_IN4_ADMA_ADC_IN4 0xc0000060
SC_P_ADC_IN5_ADMA_ADC_IN5 0xc0000060
>;
};
};
&adc0 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_adc0>;
digi,adc-ch-list = <0 1 2 3 4 5>;
status = "okay";
};
3.I can see /dev/iio:device0 device node;
4.root@CTX0800-RoHS:~# cat /sys/bus/iio/devices/iio\:device0/in_voltage_scale
1048.575927734
The value is abnormal.
5.check kernel startup log:
[ 3.085389] imx8qxp-pinctrl iomuxc: pin_config_set op failed for pin 100
[ 3.092240] imx8qxp_adc 5a880000.adc: Error applying setting, reverse things back
[ 3.100523] imx8qxp_adc 5a880000.adc: 5a880000.adc supply vref not found, using dummy regulator
as above info(point 5),ADC_IN0(pin 100) configration are conflicts with somewhere.Moreover ADC supply vref is abnormal.
Can someone help me?
BRs!
Johnny
Hi igor,
Tks for your suggestion.
I researched Linux 4.14.98_2.3.0 Documentation carefully,But They are unuseful for me.
BRs
Johnny
Hi Johnny
please check that latest rev.C0 revision used in the case and
latest linux L4.14.98_2.3.0 supporting that revision
Linux 4.14.98_2.3.0 Documentation
Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------