Huawei mode changing updated

[Dan Williams]

On Mon, 2013-11-11 at 17:01 +0100, Aleksander Morgado wrote:
> 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 :)

Tested the prefmode support, pushed a small fixup.  That part looks
fine.  I'll have to check the SYSCFG/SYSCFGEX a bit later.

Dan