9phone

Hello all,



I've been working on trying to get a pinephone kernel that can run

9front at https://github.com/driusan/9front-A64



I spent some time this weekend on the userspace getting readings off

the i2c sensors.



I've managed to use /dev/i2c*/ to get data from the:

1. Touch panel

2. Light/proximity sensor

3. Magnetometer

4. Accelerometer/gyroscope



and now I want to expose the data in a filesystem before I put it

online in some other repo.  I've done some looking around but can't

find any prior art for any of the above sensor types in Plan9.  Does

anyone know of any?  I'd like to aim for compatibility if they exist.



Assuming they don't, I'm looking for input if anyone has any strong

opinions on what the interface should look like.



Left to my own devices my plan is:



1. TouchPanel -- just write to /dev/mousein and treat touches as

   button 1.  Since it's a userspace driver we can experiment with

   multitouch later.

2. Light/proximity sensor - create a /dev/lightsensor that

   returns light readings.  A /dev/proximity read returns "close" or

   "notclose".  No ctl files or scaling.

3. Magnetometer - /dev/compass blocks until there's enough

   data to calibrate.  Reads return 3 values, x y z that are the raw

   (short int) readings.  /dev/compassctl for calibrating

   sensitivity/etc.

4. Accel/gyroscope - /dev/accel returns 6 readings of the

   raw (also short) value ax ay az gx gy gz.  /dev/accelctl

   for customizing sensitivity/etc.



x/y/z aren't the raw sensor orientation, but normalized so that +y is the

top of the screen, +x is to the right, and +z is towards the back of the

phone.



I've done the work to read the values but haven't done any work to

expose it other than printing debugging to stdout, so I'm open to

suggestions to other interfaces.



- Dave