Re: [PATCH V3] iio: pressure: hp03: Add Hope RF HP03 sensor support

[Marek Vasut <marex@denx.de>]

On 04/18/2016 03:57 PM, jic23@jic23.retrosnub.co.uk wrote:
> On 18.04.2016 14:56, Marek Vasut wrote:
>> On 04/18/2016 03:44 PM, jic23@jic23.retrosnub.co.uk wrote:
>>> On 18.04.2016 14:26, Marek Vasut wrote:
>>>> On 04/16/2016 09:40 PM, Jonathan Cameron wrote:
>>>>> On 10/04/16 21:52, Marek Vasut wrote:
>>>>>> Add support for HopeRF pressure and temperature sensor.
>>>>>>
>>>>>> This device uses two fixed I2C addresses, one for storing
>>>>>> calibration coefficients and another for accessing the ADC.
>>>>>>
>>>>>> Signed-off-by: Marek Vasut <marex@denx.de>
>>>>>> Cc: Matt Ranostay <mranostay@gmail.com>
>>>>>> Cc: Jonathan Cameron <jic23@kernel.org>
>>>>> Sorry I didn't get to this earlier in the week.
>>>>>
>>>>> Unfortunately the resulting scales don't match the standard ABI for
>>>>> these
>>>>> two channel types.
>>>>
>>>> Ah, sorry for the inconvenience.
>>>>
>>>>> Otherwise, looks good. I've cc'd the devicetree list and maintainers.
>>>>> The binding is trivial I think, but always good to give people a
>>>>> opportunity to comment.
>>>>>
>>>>> Jonathan
>>>>>> ---
>>>>>> V2: - Expand the binding document with more details on the XCLR pin
>>>>>>     - Switch from IIO_CHAN_INFO_PROCESSED to RAW + SCALE
>>>>>>     - Add failpath into hp03_update_temp_pressure() for the case
>>>>>>       when ADC readout fails. This correctly sets the XCLR pin back
>>>>>>       to LO now.
>>>>>>     - Add comment explaining the need for allocation of child device
>>>>>>       in hp03_probe().
>>>>>> V3: - Fix indent in the DT binding documentation
>>>>>>     - Report raw pressure and temperature unmodified
>>>>> Good
>>>>>>     - Report pressure scale to be 1 , since pressure is in Pa
>>>>> Standard units for pressure (see
>>>>> Documentation/ABI/testing/sysfs-bus-iio
>>>>> are KPa so it wants to report 0.001)
>>>>
>>>> OK, got it.
>>>>
>>>>>>     - Report temperature scale to be 0.01 , since temp is in 0.01C
>>>>>> steps
>>>>> Unfortunately the documented base unit for temp (originally from
>>>>> hwmon before
>>>>> we started going for SI units every time) are milli Celcius.  Thus
>>>>> the value
>>>>> reported * scale should end up in milli degrees Celcius. Hence if it
>>>>> is in 0.01
>>>>> steps the scale should be 0.1
>>>>
>>>> Shouldn't this be 10 ? The value is in 0.01C steps , so the value
>>>> has to
>>>> be multiplied by 10 to convert it into mC units.
>>> err. yes I'm clearly wrong :)
>>
>> Thanks for confirming :) V4 is coming.
> Beware, I might not be any more correct today ;)

That's fine, take your time, MW opening is far away :)

-- 
Best regards,
Marek Vasut