Re: iio: adc: add exynos5 adc driver under iio framwork

From: Guenter Roeck
Date: Wed Feb 13 2013 - 10:50:43 EST


On Wed, Feb 13, 2013 at 06:46:01PM +0530, Naveen Krishna Ch wrote:
[ ... ]
>
> Hello Guenter,
>
> I've rebase my adc driver on top of your (OF for IIO patch)
>
> My setup is like the below one. kindly, help me find the right device
> tree node params
>
> One ADC controller with 8 channels,
> 4 NTC thermistors are connected to channel 3, 4, 5 and 6 of ADC respectively
>
> ADC ch - 0
> ADC ch - 1
> ADC ch - 2
> ADC ch - 3 ------------------NTC
> ADC ch - 4 ------------------NTC
> ADC ch - 5 ------------------NTC
> ADC ch - 6 ------------------NTC
> ADC ch - 7
>
> I've started off with something like this.
>
> adc0: adc@12D10000 {
> compatible = "samsung,exynos5250-adc";
> reg = <0x12D10000 0x100>;
> interrupts = <0 106 0>;
> #io-channel-cells = <1>;
> };
>
> adc0: adc@12D10000 {
> vdd-supply = <&buck5_reg>;
>
> ncp15wb473@0 {
> compatible = "ntc,ncp15wb473";
> io-channels = <&adc0 3>;
> io-channel-names = "adc3";
> pullup-uV = <1800000>;
> pullup-ohm = <47000>;
> pulldown-ohm = <0>;
> id = <3>;
> };
>
> ncp15wb473@1 {
> compatible = "ntc,ncp15wb473";
> pullup-uV = <1800000>;
> pullup-ohm = <47000>;
> pulldown-ohm = <0>;
> io-channels = <&adc0 4>;
> io-channel-names = "adc4";
> id = <4>;
> };
> ncp15wb473@2 {
> compatible = "ntc,ncp15wb473";
> pullup-uV = <1800000>;
> pullup-ohm = <47000>;
> pulldown-ohm = <0>;
> io-channels = <&adc0 5>;
> io-channel-names = "adc5";
> id = <5>;
> };
> ncp15wb473@3 {
> compatible = "ntc,ncp15wb473";
> pullup-uV = <1800000>;
> pullup-ohm = <47000>;
> pulldown-ohm = <0>;
> io-channels = <&adc0 6>;
> io-channel-names = "adc6";
> id = <6>;
> };
> };
>
> ADC driver will use of_platform_populate() to populate the child nodes
> (ntc thermistors in my case)
>
> I've modified the NTC driver to support DT. in probe
> chan = iio_channel_get(&pdev->dev, "adcX");
> and using "id" field to use respective ADC channel to do the raw_read()
>
> Issue:
> 1. I get weird device names for thermistors starting from ncp15wb473.2
> to ncp15wb473.5

I noticed that device IDs and names created when OF is active are sometimes
not as one would expect. I never managed to get the device IDs I tried to
configure. Ultimately, it did not matter and I never bothered to track it down.

Guenter
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