[PATCH 1/3] ARM: AT91: IIO: add low and high res support for adc

[ludovic.desroches]

Hi Maxime,

On 12/20/2012 11:42 AM, Maxime Ripard wrote:
> Hi,
>
> Le 19/12/2012 19:37, Jean-Christophe PLAGNIOL-VILLARD a écrit :
>> From: Ludovic Desroches <ludovic.desroches at atmel.com>
>>
>> at91 adc offers the choice between two resolutions: low and high.
>> The low and high resolution values depends on adc IP version, as many IP
>> properties have been exposed through device tree, these settings have also
>> been added to the dt bindings.
>>
>> Update at the same time the dtsi.
>>
>> Signed-off-by: Ludovic Desroches <ludovic.desroches at atmel.com>
>> [plagnioj at jcrosoft.com: udpate current adc dt support]
>> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
>> Cc: linux-iio at vger.kernel.org
>> Cc: Nicolas Ferre <nicolas.ferre at atmel.com>
>> ---
>>   .../devicetree/bindings/arm/atmel-adc.txt          |   11 +++
>>   arch/arm/boot/dts/at91sam9260.dtsi                 |    3 +
>>   arch/arm/boot/dts/at91sam9g45.dtsi                 |    3 +
>>   arch/arm/boot/dts/at91sam9x5.dtsi                  |    3 +
>>   drivers/iio/adc/at91_adc.c                         |   74 ++++++++++++++++++--
>>   5 files changed, 90 insertions(+), 4 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt
>> index c63097d..fd2d69e 100644
>> --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt
>> +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt
>> @@ -14,9 +14,17 @@ Required properties:
>>     - atmel,adc-status-register: Offset of the Interrupt Status Register
>>     - atmel,adc-trigger-register: Offset of the Trigger Register
>>     - atmel,adc-vref: Reference voltage in millivolts for the conversions
>> +  - atmel,adc-res: List of resolution in bits supported by the ADC. List size
>> +		   must be two at least.
>> +  - atmel,adc-res-names: Contains one identifier string for each resolution
>> +			 in atmel,adc-res property. "lowres" and "highres"
>> +			 identifiers are required.
>>
>>   Optional properties:
>>     - atmel,adc-use-external: Boolean to enable of external triggers
>> +  - atmel,adc-use-res: String corresponding to an identifier from
>> +		       atmel,adc-res-names property. If not specified, the highest
>> +		       resolution will be used.
>
>
> I'm wondering, why are you using such a complex dt parsing code, and
> bindings, when you only requires a boolean to switch between 8 and 10
> bits mode (which seem to be the only thing you support)?

We will have a 10 and 12 bits mode on future ADCs and I would like to 
have something which could manage more than two resolutions if it 
happens one day.

Regards

Ludovic

>
> Maxime
>