On Sun, Nov 25, 2018 at 08:35:07AM +0000, Jonathan Cameron wrote: > On Sat, 24 Nov 2018 23:14:13 +0100 > Tomasz Duszynski <tduszyns@xxxxxxxxx> wrote: > > > Measuring particulate matter in ug / m3 (micro-grams per cubic meter) > > is de facto standard. Existing air quality sensors usually follow > > this convention and are capable of returning measurements using > > this unit. > > > > IIO currently does not offer suitable channel type for this > > type of measurements hence this patch adds this. > > > > In addition, two modifiers are introduced used for distinguishing > > between coarse (PM10) and fine particles (PM2p5) measurements, i.e > > IIO_MOD_PM10 and IIO_MOD_PM2p5. > I initially wondered why these particular numbers and why don't > we provide an attribute specify this separately? > > However google suggests these two are pretty much the only > ones anyone worries about in pollution sensors. I ended > up fairly quickly at the EPA website > https://www.epa.gov/pm-pollution/table-historical-particulate-matter-pm-national-ambient-air-quality-standards-naaqs > which tells me these two have be used since about 1987. > Usually sensors can measure more than just PM10 and PM2.5. Fairy common is measurement of PM1.0. SPS30 additionally measures PM4.0 but frankly I don't now know exactly what's the real usecase for that. > So I think the modifier route is the right approach here > (I think we've gotten this wrong in the past such as light > sensor colours where the list keeps on growing). > > I would like a reference or two in the docs though to point > people to these definitions. > Okay, will add something reasonable so everyone interested could get the basic idea quickly. > Thanks, > > Jonathan > > > > > Signed-off-by: Tomasz Duszynski <tduszyns@xxxxxxxxx> > > --- > > Documentation/ABI/testing/sysfs-bus-iio | 11 ++++++++++- > > drivers/iio/industrialio-core.c | 3 +++ > > include/uapi/linux/iio/types.h | 3 +++ > > tools/iio/iio_event_monitor.c | 6 ++++++ > > 4 files changed, 22 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio > > index 8127a08e366d..ce0ed140660d 100644 > > --- a/Documentation/ABI/testing/sysfs-bus-iio > > +++ b/Documentation/ABI/testing/sysfs-bus-iio > > @@ -1684,4 +1684,13 @@ KernelVersion: 4.18 > > Contact: linux-iio@xxxxxxxxxxxxxxx > > Description: > > Raw (unscaled) phase difference reading from channel Y > > - that can be processed to radians. > > \ No newline at end of file > > + that can be processed to radians. > > + > > +What: /sys/bus/iio/devices/iio:deviceX/in_massconcentration_pm2p5_input > > +What: /sys/bus/iio/devices/iio:deviceX/in_massconcentrationY_pm2p5_input > > +What: /sys/bus/iio/devices/iio:deviceX/in_massconcentration_pm10_input > > +What: /sys/bus/iio/devices/iio:deviceX/in_massconcentrationY_pm10_input > > +KernelVersion: 4.21 > > +Contact: linux-iio@xxxxxxxxxxxxxxx > > +Description: > > + Mass concentration reading of particulate matter in ug / m3. > > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c > > index a062cfddc5af..2a9ef600c1fb 100644 > > --- a/drivers/iio/industrialio-core.c > > +++ b/drivers/iio/industrialio-core.c > > @@ -87,6 +87,7 @@ static const char * const iio_chan_type_name_spec[] = { > > [IIO_GRAVITY] = "gravity", > > [IIO_POSITIONRELATIVE] = "positionrelative", > > [IIO_PHASE] = "phase", > > + [IIO_MASSCONCENTRATION] = "massconcentration", > > }; > > > > static const char * const iio_modifier_names[] = { > > @@ -127,6 +128,8 @@ static const char * const iio_modifier_names[] = { > > [IIO_MOD_Q] = "q", > > [IIO_MOD_CO2] = "co2", > > [IIO_MOD_VOC] = "voc", > > + [IIO_MOD_PM2p5] = "pm2p5", > > + [IIO_MOD_PM10] = "pm10", > > }; > > > > /* relies on pairs of these shared then separate */ > > diff --git a/include/uapi/linux/iio/types.h b/include/uapi/linux/iio/types.h > > index 92baabc103ac..465044b42af5 100644 > > --- a/include/uapi/linux/iio/types.h > > +++ b/include/uapi/linux/iio/types.h > > @@ -46,6 +46,7 @@ enum iio_chan_type { > > IIO_GRAVITY, > > IIO_POSITIONRELATIVE, > > IIO_PHASE, > > + IIO_MASSCONCENTRATION, > > }; > > > > enum iio_modifier { > > @@ -87,6 +88,8 @@ enum iio_modifier { > > IIO_MOD_VOC, > > IIO_MOD_LIGHT_UV, > > IIO_MOD_LIGHT_DUV, > > + IIO_MOD_PM2p5, > > + IIO_MOD_PM10, > > }; > > > > enum iio_event_type { > > diff --git a/tools/iio/iio_event_monitor.c b/tools/iio/iio_event_monitor.c > > index ac2de6b7e89f..f0fcfeddba2b 100644 > > --- a/tools/iio/iio_event_monitor.c > > +++ b/tools/iio/iio_event_monitor.c > > @@ -60,6 +60,7 @@ static const char * const iio_chan_type_name_spec[] = { > > [IIO_GRAVITY] = "gravity", > > [IIO_POSITIONRELATIVE] = "positionrelative", > > [IIO_PHASE] = "phase", > > + [IIO_MASSCONCENTRATION] = "massconcentration", > > }; > > > > static const char * const iio_ev_type_text[] = { > > @@ -115,6 +116,8 @@ static const char * const iio_modifier_names[] = { > > [IIO_MOD_Q] = "q", > > [IIO_MOD_CO2] = "co2", > > [IIO_MOD_VOC] = "voc", > > + [IIO_MOD_PM2p5] = "pm2p5", > > + [IIO_MOD_PM10] = "pm10", > > }; > > > > static bool event_is_known(struct iio_event_data *event) > > @@ -156,6 +159,7 @@ static bool event_is_known(struct iio_event_data *event) > > case IIO_GRAVITY: > > case IIO_POSITIONRELATIVE: > > case IIO_PHASE: > > + case IIO_MASSCONCENTRATION: > > break; > > default: > > return false; > > @@ -200,6 +204,8 @@ static bool event_is_known(struct iio_event_data *event) > > case IIO_MOD_Q: > > case IIO_MOD_CO2: > > case IIO_MOD_VOC: > > + case IIO_MOD_PM2p5: > > + case IIO_MOD_PM10: > > break; > > default: > > return false; >
