Messages in this thread | | | Subject | Re: [PATCH 1/2] dt-bindings: iio: stm32-adc: add option to set resolution | From | Fabrice Gasnier <> | Date | Tue, 28 Feb 2017 09:21:49 +0100 |
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On 02/25/2017 04:11 PM, Jonathan Cameron wrote: > On 24/02/17 16:04, Fabrice Gasnier wrote: >> On 02/19/2017 01:09 PM, Jonathan Cameron wrote: >>> On 15/02/17 16:55, Fabrice Gasnier wrote: >>>> Add documentation for 'st,adc-res' dt optional property. >>>> >>>> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> >>> I'm happy with this, but would like to leave time for a device tree review. >>> >>> Ultimately we may well want to make this a generic property and call it something >>> like adc-resolution but perhaps we need to wait until we have a few more devices >>> supporting setting it via device tree to figure out what the best interface is. >>> It would exactly be a problem to support this as a deprecated binding at that >>> point. >> >> Hi Jonathan, >> >> I agree with you on this... It may be better to have generic property >> for this, especially if you see that it will come in the near future. >> May I suggest this prop to be less restrictive, e.g. like >> resolution-bits as is may also be worth for other device types, e.g. >> DAC as an example ?> > Sure, why not - no loss of meaning here. We may never use it for anything > else but that doesn't matter.
Hi Jonathan,
Following Rob's comment, how you see such a common property can be integrated. Currently I don't see much devices are doing this. Do you have ideas or preferences on this ?
- Do you think replacing 'st,adc-res' by 'resolution-bits' in current patchset is enough for now ? - Or do I need to add dt parsing routine in IIO core, e.g. as simple as of_iio_get_resolution(), or something like this ? Or parsing routine that may fill in a common properties structure (but only resolution will be there from the start)...
Please let me know.
Thanks, Fabrice
>>> >>> Give me a poke if we hear nothing from Rob or Mark for say another week. >> >> No news yet, but it can wait a little longer. > Rob / Mark, can you take a look at this if you have time? > > Thanks, > > Jonathan >> >> Please advise, >> Regards, >> Fabrice >> >>> >>> Thanks, >>> >>> Jonathan >>> >>>> --- >>>> Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt | 4 ++++ >>>> 1 file changed, 4 insertions(+) >>>> >>>> diff --git a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt >>>> index 5dfc88e..45f7ff2 100644 >>>> --- a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt >>>> +++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt >>>> @@ -57,6 +57,9 @@ Optional properties: >>>> - dmas: Phandle to dma channel for this ADC instance. >>>> See ../../dma/dma.txt for details. >>>> - dma-names: Must be "rx" when dmas property is being used. >>>> +- st,adc-res: Resolution (bits) to use for conversions. Must match device >>>> + available resolutions (e.g. can be 6, 8, 10 or 12 on stm32f4). Default >>>> + is maximum resolution if unset. >>>> >>>> Example: >>>> adc: adc@40012000 { >>>> @@ -84,6 +87,7 @@ Example: >>>> st,adc-channels = <8>; >>>> dmas = <&dma2 0 0 0x400 0x0>; >>>> dma-names = "rx"; >>>> + st,adc-res = <8>; >>>> }; >>>> ... >>>> other adc child nodes follow... >>>> >>> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-iio" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >
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