Configuring Oversampling on STM32MP135F ADC: Parameter Ignored

[giz]

For a project using the STM32MP135F Discovery kit, I configured ADC1 with an oversampling ratio of 16. However, in sysfs, I can see that the device tree parameter is being ignored:

 

# cat /sys/bus/iio/devices/iio:device0/oversampling_ratio
1

 

What am I missing?

My device tree:

 

#include "stm32mp135f-dk.dts"

...

&pinctrl {
	adc1_pins_a: adc1-0 {
		pins {
			pinmux =
				<STM32_PINMUX('A', 5, ANALOG)>, /* ADC1_INP2 */
				<STM32_PINMUX('A', 0, ANALOG)>; /* ADC1_INP7 */
		};
	};
};

&adc_1 {
	pinctrl-names = "default";
	pinctrl-0 = <&adc1_pins_a>;
	vdda-supply = <&scmi_vdd_adc>;
	vref-supply = <&scmi_vdd_adc>;
	status = "okay";
	adc1: adc@0 {
		status = "okay";
		oversampling-ratio = <16>;
		/delete-node/ channel@6;
		/delete-node/ channel@12;
		channel@2 {
			reg = <2>;
			st,min-sample-time-ns = <100000>;
		};
		channel@7 {
			reg = <7>;
			st,min-sample-time-ns = <100000>;
		};
	};
};

 

 

 

[Gregory PLANCHON]

Hi @giz 

 

I saw this old post for MP15 which should be able to guide you in your use case :

https://community.st.com/t5/stm32-mpus-products/stm32mp15x-adc-oversample/td-p/573095

If you need more information, don't hesitate to come back to me.

 

Regards,

Grégory