On 29/12/14 15:05, Tirdea, Irina wrote: > > >> -----Original Message----- >> From: Jonathan Cameron [mailto:jic23@xxxxxxxxxx] >> Sent: 26 December, 2014 15:31 >> To: Tirdea, Irina; linux-iio@xxxxxxxxxxxxxxx >> Cc: linux-kernel@xxxxxxxxxxxxxxx; Dogaru, Vlad; Baluta, Daniel; Hartmut Knaack; Lars-Peter Clausen; Peter Meerwald >> Subject: Re: [PATCH 4/8] iio: core: Introduce IO_CHAN_INFO_CALIBWEIGHT >> >> On 19/12/14 22:57, Irina Tirdea wrote: >>> Some devices need the weight of the user to compute other >>> parameters. One of this devices is Freescale's MMA9553L >>> (http://www.freescale.com/files/sensors/doc/ref_manual/MMA9553LSWRM.pdf) >>> that needs the weight of the user to compute the number of calories burnt. >>> >>> Signed-off-by: Irina Tirdea <irina.tirdea@xxxxxxxxx> >>> --- >>> Documentation/ABI/testing/sysfs-bus-iio | 7 +++++++ >>> drivers/iio/industrialio-core.c | 1 + >>> include/linux/iio/iio.h | 1 + >>> 3 files changed, 9 insertions(+) >>> >>> diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio >>> index 07acef7..e480175 100644 >>> --- a/Documentation/ABI/testing/sysfs-bus-iio >>> +++ b/Documentation/ABI/testing/sysfs-bus-iio >>> @@ -351,6 +351,13 @@ Description: >>> to compute the stride length, distance, speed and activity >>> type. >>> >>> +What: /sys/bus/iio/devices/iio:deviceX/in_steps_calibweight >>> +KernelVersion: 3.19 >>> +Contact: linux-iio@xxxxxxxxxxxxxxx >>> +Description: >>> + Weight of the user (in kg). It is needed by some pedometers >>> + to compute the calories burnt by the user. >> How about grams? Nice to keep to SI units going forward (I appreciate we >> have broken that for what seemed like good reasons at the time) in one >> or two places, but it makes it much harder to define consistent interfaces in the >> long run. > > According to SI [1] kg is the base unit for mass, so this was the obvious first choice. I'd forgotten that piece if 'entirely intuitive' unit choice ;) > I have nothing against using grams, but it is not clear to me why using grams would make it easier to define consistent interfaces in the long run. > I am probably missing something, so could you please clarify this? kg fine as we have a good argument for why ;) The consistent interface bit comes when we start getting compound units if we had picked non SI choices (such is mA and mV - which we are stuck with unfortunately). Now as Joules are kg m^2 s^-2 for example, we are on good grounds with the kg. > > Thanks, > Irina > > [1] http://www.bipm.org/en/measurement-units/ > >> J >>> + >>> What: /sys/bus/iio/devices/iio:deviceX/in_accel_scale_available >>> What: /sys/.../iio:deviceX/in_voltageX_scale_available >>> What: /sys/.../iio:deviceX/in_voltage-voltage_scale_available >>> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c >>> index 5e50aca..4c435c8 100644 >>> --- a/drivers/iio/industrialio-core.c >>> +++ b/drivers/iio/industrialio-core.c >>> @@ -124,6 +124,7 @@ static const char * const iio_chan_info_postfix[] = { >>> [IIO_CHAN_INFO_INT_TIME] = "integration_time", >>> [IIO_CHAN_INFO_ENABLE] = "en", >>> [IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight", >>> + [IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight", >>> }; >>> >>> /** >>> diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h >>> index 878d861..752a929 100644 >>> --- a/include/linux/iio/iio.h >>> +++ b/include/linux/iio/iio.h >>> @@ -40,6 +40,7 @@ enum iio_chan_info_enum { >>> IIO_CHAN_INFO_INT_TIME, >>> IIO_CHAN_INFO_ENABLE, >>> IIO_CHAN_INFO_CALIBHEIGHT, >>> + IIO_CHAN_INFO_CALIBWEIGHT, >>> }; >>> >>> enum iio_shared_by { >>> > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
