i.MX ProcessorsのトピックRe: IMX6UL ADC test from user space

IMX6UL ADC test from user space

anshulkhare — Mon, 15 Jan 2018 17:02:27 GMT

Hi All,

I want to do an adc test on imx6ul board. But, I am not able to see anything under /sys/bus/iio/devices/.

I have enabled the ADC support in kernel configurations.

My dtsi(imx6ul.dtsi) file contains :

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 = <2>;
clock-names = "adc";
status = "disabled";
};

Is there anything more to be done to see the devices in /sys/bus/iio/devices/.

Could anyone kindly help me out on this ?

Re: IMX6UL ADC test from user space

igorpadykov — Mon, 15 Jan 2018 23:04:56 GMT

Hi Anshul

please try procedures described in sect.53.3.3 Programming Interface

attached Linux Manual, use nxp bsps described on

https://www.nxp.com/support/developer-resources/run-time-software/i.mx-developer-resources/i.mx-6series-i.mx-7series-software-and-development-tool-resources:IMX_SW

Best regards
igor
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Re: IMX6UL ADC test from user space

anshulkhare — Tue, 16 Jan 2018 07:02:13 GMT

Hello igor,

Thank you for the suggestion. But as per the document, we have enabled freescale vf610 ADC driver as well as ADC driver for imx6 (the board we are using). Still we are not able to see any devices under /sys/bus/iio/devices/.

Is there anything else we are supposed to do?

Re: IMX6UL ADC test from user space

igorpadykov — Tue, 16 Jan 2018 07:31:07 GMT

Hi Anshul

according to document interface is available at

/sys/devices/soc0/soc.1/2200000.aips-bus/

Best regards
igor

Re: IMX6UL ADC test from user space

anshulkhare — Tue, 16 Jan 2018 07:46:47 GMT

Hi igor,

There is nothing as soc.1 under /sys/devices/soc0/.

I can see only family, machine, power(dir), revision, soc_id, subsystem(link), uevent under this directory.

Re: IMX6UL ADC test from user space

igorpadykov — Tue, 16 Jan 2018 07:50:58 GMT

Hi Anshul

please try demo images

https://www.nxp.com/webapp/Download?colCode=L4.1.15_2.0.0_iMX6UL&appType=license&location=null

Best regards
igor

Re: IMX6UL ADC test from user space

fabio_poiatti — Wed, 21 Aug 2019 08:14:24 GMT

I have the same problem ... and the demo image does not work signalling a

Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

Any suggestion?

thanks

Re: IMX6UL ADC test from user space

fabio_poiatti — Thu, 29 Aug 2019 12:10:06 GMT

any news?

always in the same condition .... and I also modified the DTS file to produce the adc1 anabled ..

but always I didn't see anything in the /sys directories

Thanks

Re: IMX6UL ADC test from user space

huf — Tue, 03 Sep 2019 05:59:22 GMT

&adc1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_adc1>;
vref-supply = <&reg_vref_3v3>;
status = "okay";
};

pinctrl_adc1 define the pins.

I think the key is: status = "okay";

you will see /sys/bus/iio/devices/iio:device0，document is wrong.

Re: IMX6UL ADC test from user space

fabio_poiatti — Tue, 03 Sep 2019 11:02:25 GMT

I don't se anything ...

is it correct the pin definition

&iomuxc {
imx6ul-ccimx6ul {
/* Uncomment specific pins of the ADC channels enabled in 'adc-ch-list' */
pinctrl_adc1: adc1grp {
fsl,pins = <
/* GPIO1_4/ADC1_IN4 (pin 7 of the expansion header) */
MX6UL_PAD_GPIO1_IO04__GPIO1_IO04 0x80
>;
};
};

thanks

Re: IMX6UL ADC test from user space

huf — Wed, 04 Sep 2019 01:23:43 GMT

my dts：

pinctrl_adc1: adc1grp {
fsl,pins = <
MX6UL_PAD_GPIO1_IO03__GPIO1_IO03 0x1b0b0
>;
};

ADC_IN4, the i.MX Pins Tools recommed configuration is

MX6UL_PAD_GPIO1_IO04__GPIO1_IO04 0x000010B0

adn maybe your kernel configuration is not correct.

Re: IMX6UL ADC test from user space

fabio_poiatti — Thu, 05 Sep 2019 14:59:14 GMT

now I see something but I have some doubts regarding the meaning of pinctrl_adc1 ...

1) in your example you set pinctrl_adc1 as MX6UL_PAD_GPIO1_IO03__GPIO1_IO03 with value 0x10B0

is it correct? is the initial value for IOMUXC_SW_PAD_CTL_PAD_GPIO1_IO03 register? The same for

MX6UL_PAD_GPIO1_IO04__GPIO1_IO04

2) how is possible to set the adc input channel? Or in other words ... how is the relationship

beetwen the adc input channel, the bit0.4 of ADC1.HC0.ADCH register and the setting as

pinctrl_adc1 in the DTB file?

thanks

Re: IMX6UL ADC test from user space

fabio_poiatti — Mon, 09 Sep 2019 14:48:58 GMT

Hi,

I tried the MX6UL_PAD_GPIO1_IO04__GPIO1_IO04 as ADC_IN4 connecting the physical pin to 3.3V

or 0V but I read always a number near 4095 as I read a different gpio pin ...

Any suggestion?

Thanks

Re: IMX6UL ADC test from user space

huf — Tue, 10 Sep 2019 06:20:25 GMT

num-channels = <5>;

and then try: cat /sys/bus/iio/devices/iio\:device0/in_voltage4_raw

Re: IMX6UL ADC test from user space

fabio_poiatti — Wed, 18 Sep 2019 08:05:00 GMT

It is working :-)

many thanks