Huawei mode changing updated

[Aleksander Morgado]

Hey,

I spent some time these past weeks implementing allowed/preferred mode
changing for the new ^SYSCFGEX-capable Huawei devices [1]. This new
^SYSCFGEX command is an extension of ^SYSCFG thought for LTE devices
(like the ME906E) but is also now available in non-LTE devices (like the
MU736). Note that I only implemented mode changing, *not* explicit
frequency band changing.

While developing the support for ^SYSCFGEX, I also ended up developing
supported mode checks with AT^SYSCFG=? and AT^PREFMODE=?, instead of
blindly relying that these are supported.

I've tested the new ^SYSCFGEX support both with a ME906E and a MU736[2],
and ^SYSCFG support with a E220, but *haven't* tested with AT^PREFMODE
as I don't have a CDMA Huawei modem around.

This new development is available in the 'aleksander/huawei-modes'
branch upstream. Further tests and comments are very welcome :)


[1] https://bugzilla.gnome.org/show_bug.cgi?id=700934
[2] Thanks to Huawei for sending me those!

-- 
Aleksander