Re: [PATCH] iio: pressure: mpl115: fix temperature offset sign

[Jonathan Cameron <jic23@kernel.org>]

On 26/01/16 12:33, Peter Meerwald-Stadler wrote:
> On Sun, 24 Jan 2016, Jonathan Cameron wrote:
> 
>> On 20/01/16 16:07, Akinobu Mita wrote:
>>> According to the datasheet, the resolusion of temperature sensor is
>>> -5.35 counts/C. Temperature ADC is 472 counts at 25C.
>>> (https://www.sparkfun.com/datasheets/Sensors/Pressure/MPL115A1.pdf
>>> NOTE: This is older revision, but this information is removed from the
>>> latest datasheet from nxp somehow)
>>>
>>> Temp [C] = (Tadc - 472) / -5.35 + 25
>>>          = (Tadc - 605.750000) * -0.186915888
>>>
>>> So the correct offset is -605.750000.
> 
> Acked-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Applied to the fixes-togreg branch and marked for stable.

Thanks,

Jonathan
>  
>>> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
>>> Cc: Jonathan Cameron <jic23@kernel.org>
>>> Cc: Hartmut Knaack <knaack.h@gmx.de>
>>> Cc: Lars-Peter Clausen <lars@metafoo.de>
>>> Cc: Peter Meerwald <pmeerw@pmeerw.net>
>>> Cc: linux-iio@vger.kernel.org
>> Peter,
>>
>> I'd like your Ack on this given it is your driver.  That way
>> I can be lazy and not cross check the datasheet myself.
>>
>> Jonathan
>>> ---
>>>  drivers/iio/pressure/mpl115.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/iio/pressure/mpl115.c b/drivers/iio/pressure/mpl115.c
>>> index 138344c..73f2f0c 100644
>>> --- a/drivers/iio/pressure/mpl115.c
>>> +++ b/drivers/iio/pressure/mpl115.c
>>> @@ -118,7 +118,7 @@ static int mpl115_read_raw(struct iio_dev *indio_dev,
>>>  		*val = ret >> 6;
>>>  		return IIO_VAL_INT;
>>>  	case IIO_CHAN_INFO_OFFSET:
>>> -		*val = 605;
>>> +		*val = -605;
>>>  		*val2 = 750000;
>>>  		return IIO_VAL_INT_PLUS_MICRO;
>>>  	case IIO_CHAN_INFO_SCALE:
>>>
>>
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>