Iio slot to support dynamic iio device numbering

device
1

The order in which i2c sensors are probed by the kernel is not fixed and the
/dev/iio:device{X} number allocation is dynamic. When system reboots, the iio devices order would change.

On my system, there are three sensor devices:

hts221
lng2dm
lps22hb

The gadget snap exposed the three iio slots:

iio0:
    interface: iio 
    path: /dev/iio:device0
iio1:
    interface: iio 
    path: /dev/iio:device1
iio2:
    interface: iio 
    path: /dev/iio:device2

The snap should not connect all the iio slots which is insecure.
The iio slot needs a new attribute to identify the iio device number mapping.

Just like serial-port slot provides PID/VID attributes to identify the USB serial port device.
For iio slot, maybe we could have a “name” attribute to identify the sensor device. The “name” information can be obtained from sysfs:

/sys/bus/iio/devices/iio:device0/name

Thoughts?

Thanks,
Darren

2

We were actually discussing allowing the shipment of udev rules in the gadget snap to assign fixed naming to dynamically assigned devices yesterday at the Ubuntu Rally. @niemeyer i think the above is another example where this would be helpful …