trying to get qom-{get,set} working with gpio on qemu-x86_64

[Ben Dooks]

I have been trying to get qom-get/qom-set scripts working to make an
virtual GPIO device on qemu-system-x86_64. I have a working TMP105
and I can see the MAX7310 being instantiated with the relevant Linux
devices showing up (i2c, gpio).

I can read the sensor from QEmu console:

(qemu)  qom-get /machine/peripheral/sensor temperature
20000
(qemu) qom-set  /machine/peripheral/sensor temperature 19000
(qemu)  qom-get /machine/peripheral/sensor temperature
19000

When trying to get or set anything from the GPIO chip it doesn't
seem to be working. How do I get this working, I haven't found
any useful reference online and need some help:

(qemu) qom-set /machine/peripheral/gpio unnamed-gpio-out[0] 0
Error: Device '0' not found
(qemu) qom-set /machine/peripheral/gpio unnamed-gpio-in[0] 0
Error: Insufficient permission to perform this operation

I am also having issues with both sensor and the gpio via the
qom-set, as so:

> $ sudo ./scripts/qmp/qom-set --socket ~/qmp.sock 
> /machine/peripheral/sensor.temperature 20200
> ExecuteError: Invalid parameter type for 'temperature', expected: integer
> Task was destroyed but it is pending!

Is this also a known issue?


QEmu is git checkout from 31e3caf21b6cdf54d11f3744b8b341f07a30b5d7 as
needed to enable the relevant QEmu configs so built from source. The
command line additions are:

        -device max7310,id=gpio,address=0x20
        -device tmp105,id=sensor,address=0x50
        -qmp unix:$HOME/qmp.sock,server,nowait

--
Ben Dooks                               http://www.codethink.co.uk/
Senior Engineer                         Codethink - Providing Genius

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