Hi everybody,
I've an imx6sx board and I now need to use the adc, reading sampled value in my C program.
So, I've enabled adc2 in the dts, that's the code (exactly the same provided by Freescale):
.dtsi:
adc2: adc@02284000 {
compatible = "fsl,imx6sx-adc", "fsl,vf610-adc";
reg = <0x02284000 0x4000>;
interrupts = <GIC_SPI 101 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&clks IMX6SX_CLK_IPG>;
num-channels = <4>;
clock-names = "adc";
status = "disabled";
};
.dts:
&adc2 {
vref-supply = <®_vref_3v3>;
status = "okay";
};
Everything works in the right way if I cat the files in /sys/bus/iio/devices/iio:device0/ , getting the right voltage values.
Problems begin when trying to cat the node /dev/iio:device0, which returns "read error: Invalid argument". From my C program I'm able to open this device file, but when I'm going to read it, I still (obviously) get errorno -22, therfore "Invalid argument".
I've spent some hours googling and what I've found is that the device node represents a buffer where readings of all channels are "saved". Also, it seems that device driver vf610-adc has no buffer support, am I right? Is this the reason why I can't read the node?
In that case, how I can get adc readings in my C program (I'm just interested in only one of the 4 channels value)?
Many thanks
Andrea
