Skip to content

Support polling/non-compensated magnetometers

I would like to get the compass exposed to Geoclue on this device, but iio-sensor-proxy doesn't appear to be finding it.

The device is the LIS3MDL, using the st_sensors_i2c driver:

$ lsmod | grep st:

st_sensors_i2c         16384  1 st_magn_i2c
st_magn                20480  1 st_magn_i2c
st_sensors             24576  3 st_magn_i2c,st_magn
industrialio_triggered_buffer    16384  2 inv_mpu6050,st_magn
kfifo_buf              16384  1 industrialio_triggered_buffer

$ uname -a:

Linux mobian 5.7-pinephone #5.7.0+pinephone5 SMP PREEMPT Mon Jul 6 15:28:18 CEST 2020 aarch64 GNU/Linux

I am able to read the raw output directly from sysfs with e.g. cat /sys/bus/iio/devices/iio:device3/in_magn_x_raw.

The relevant $ udevadm info --export-db:

N: iio:device3
L: 0
E: DEVPATH=/devices/platform/soc/1c2b000.i2c/i2c-1/1-001e/iio:device3
E: SUBSYSTEM=iio
E: DEVNAME=/dev/iio:device3
E: DEVTYPE=iio_device
E: OF_NAME=lis3mdl
E: OF_FULLNAME=/soc/i2c@1c2b000/lis3mdl@1e
E: OF_COMPATIBLE_0=st,lis3mdl-magn
E: OF_COMPATIBLE_N=1
E: MAJOR=248
E: MINOR=3

P: /devices/platform/soc/1c2b000.i2c/i2c-1/1-001e/trigger0
L: 0
E: DEVPATH=/devices/platform/soc/1c2b000.i2c/i2c-1/1-001e/trigger0
E: SUBSYSTEM=iio

$ gdbus introspect --system --dest net.hadess.SensorProxy --object-path /net/hadess/SensorProxy:

  interface org.freedesktop.DBus.Properties {
    methods:
      Get(in  s interface_name,
          in  s property_name,
          out v value);
      GetAll(in  s interface_name,
             out a{sv} properties);
      Set(in  s interface_name,
          in  s property_name,
          in  v value);
    signals:
      PropertiesChanged(s interface_name,
                        a{sv} changed_properties,
                        as invalidated_properties);
    properties:
  };
  interface org.freedesktop.DBus.Introspectable {
    methods:
      Introspect(out s xml_data);
    signals:
    properties:
  };
  interface org.freedesktop.DBus.Peer {
    methods:
      Ping();
      GetMachineId(out s machine_uuid);
    signals:
    properties:
  };
  interface net.hadess.SensorProxy {
    methods:
      ClaimAccelerometer();
      ReleaseAccelerometer();
      ClaimLight();
      ReleaseLight();
      ClaimProximity();
      ReleaseProximity();
    signals:
    properties:
      readonly b HasAccelerometer = true;
      readonly s AccelerometerOrientation = 'undefined';
      readonly b HasAmbientLight = true;
      readonly s LightLevelUnit = 'lux';
      readonly d LightLevel = 0.40000000000000002;
      readonly b HasProximity = true;
      readonly b ProximityNear = false;
  };
  node Compass {
  };
};

G_MESSAGES_DEBUG=all iio-sensor-proxy:

** (process:5980): DEBUG: 00:11:41.829: Found device /sys/devices/platform/soc/1c2b000.i2c/i2c-1/1-0048/iio:device1 of type ambient light sensor at IIO Polling Light sensor
** (process:5980): DEBUG: 00:11:41.829: Found IIO poll proximity sensor at /sys/devices/platform/soc/1c2b000.i2c/i2c-1/1-0048/iio:device1
** (process:5980): DEBUG: 00:11:41.830: Found device /sys/devices/platform/soc/1c2b000.i2c/i2c-1/1-0048/iio:device1 of type proximity at IIO Poll proximity sensor

** (process:5980): WARNING **: 00:11:41.835: Could not find trigger name associated with /sys/devices/platform/soc/1c2b000.i2c/i2c-1/1-0068/iio:device2
** (process:5980): DEBUG: 00:11:41.835: Found IIO poll accelerometer at /sys/devices/platform/soc/1c2b000.i2c/i2c-1/1-0068/iio:device2
** (process:5980): DEBUG: 00:11:41.835: No auto-detected location, falling back to display location
** (process:5980): DEBUG: 00:11:41.836: Found device /sys/devices/platform/soc/1c2b000.i2c/i2c-1/1-0068/iio:device2 of type accelerometer at IIO Poll accelerometer
** (process:5980): DEBUG: 00:11:41.859: No auto-detected location, falling back to display location
** (process:5980): DEBUG: 00:11:41.859: Attribute in_accel_scale ('0.000598') found on sysfs
** (process:5980): DEBUG: 00:11:41.860: Near level: 250
** (process:5980): DEBUG: 00:11:41.867: Handling driver refcounting method 'ClaimLight' for ambient light sensor device
** (process:5980): DEBUG: 00:11:41.965: Light read from IIO: 4.000000, (scale 0.100000)
** (process:5980): DEBUG: 00:11:41.965: Light level sent by driver (quirk applied): 0.400000 (unit: lux)
...

Running monitor-sensor as geoclue reports No compass. Setting FAKE_COMPASS=1 doesn't appear to change anything.

apt tells me I have iio-sensor-proxy version 3.0 installed.

Edited by Bastien Nocera