* [PATCH] iio: pressure: mpl115: fix temperature offset sign
@ 2016-01-20 16:07 Akinobu Mita
2016-01-24 16:33 ` Jonathan Cameron
0 siblings, 1 reply; 4+ messages in thread
From: Akinobu Mita @ 2016-01-20 16:07 UTC (permalink / raw)
To: linux-iio
Cc: Akinobu Mita, Jonathan Cameron, Hartmut Knaack,
Lars-Peter Clausen, Peter Meerwald
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.
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
---
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:
--
2.5.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] iio: pressure: mpl115: fix temperature offset sign
2016-01-20 16:07 [PATCH] iio: pressure: mpl115: fix temperature offset sign Akinobu Mita
@ 2016-01-24 16:33 ` Jonathan Cameron
2016-01-26 12:33 ` Peter Meerwald-Stadler
0 siblings, 1 reply; 4+ messages in thread
From: Jonathan Cameron @ 2016-01-24 16:33 UTC (permalink / raw)
To: Akinobu Mita, linux-iio
Cc: Hartmut Knaack, Lars-Peter Clausen, Peter Meerwald
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.
>
> 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:
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] iio: pressure: mpl115: fix temperature offset sign
2016-01-24 16:33 ` Jonathan Cameron
@ 2016-01-26 12:33 ` Peter Meerwald-Stadler
2016-01-30 16:08 ` Jonathan Cameron
0 siblings, 1 reply; 4+ messages in thread
From: Peter Meerwald-Stadler @ 2016-01-26 12:33 UTC (permalink / raw)
To: Jonathan Cameron
Cc: Akinobu Mita, linux-iio, Hartmut Knaack, Lars-Peter Clausen
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>
> > 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:
> >
>
> --
> 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
>
--
Peter Meerwald-Stadler
+43-664-2444418 (mobile)
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] iio: pressure: mpl115: fix temperature offset sign
2016-01-26 12:33 ` Peter Meerwald-Stadler
@ 2016-01-30 16:08 ` Jonathan Cameron
0 siblings, 0 replies; 4+ messages in thread
From: Jonathan Cameron @ 2016-01-30 16:08 UTC (permalink / raw)
To: Peter Meerwald-Stadler
Cc: Akinobu Mita, linux-iio, Hartmut Knaack, Lars-Peter Clausen
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:
>>>
>>
>> --
>> 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
>>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-01-30 16:08 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2016-01-20 16:07 [PATCH] iio: pressure: mpl115: fix temperature offset sign Akinobu Mita
2016-01-24 16:33 ` Jonathan Cameron
2016-01-26 12:33 ` Peter Meerwald-Stadler
2016-01-30 16:08 ` Jonathan Cameron
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