Adding Telit ME310G1-WW support

[Aleksander Morgado]

Hey!

> I've attached a patch which uses the "custom regex" feature of the
> existing parser in order to detect PPP and say that things are good.
> A few things to note:
>
> * I created the regex based on data I saw output from my modem.  At
> best it is correct, at worst it won't do any harm.

I find this regex is extremely specific to your usecase. As you said
it may be a fix, or it may not do anything, that isn't a complete
solution, and I think we should try to find some other way to handle
this if possible.

I find it very very weird that the modem doesn't reply a CONNECT
response after the ATD, that would be a very weird firmware bug! Maybe
the TTY we're using for connection isn't the correct one? @Daniele
Palmas @Carlo Lobrano Do you guys have any idea of why this may be
happening in the ME310?

> * Ideally I would only use this for the ME310 modem, but I didn't see
> a way to do that in the plugin.  I'm certainly open to suggestions.

If we needed a quirk like this one, we could flag via udev with a new udev tag.

> This particular device has a second port configuration (1bc7:1102),
> which which  looks like this:
>
> /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=atmel-ehci/3p, 480M
>     |__ Port 2: Dev 7, If 0, Class=Vendor Specific Class, Driver=option, 480M
>     |__ Port 2: Dev 7, If 1, Class=Vendor Specific Class, Driver=option, 480M
>     |__ Port 2: Dev 7, If 2, Class=Vendor Specific Class, Driver=option, 480M
>     |__ Port 2: Dev 7, If 3, Class=Communications, Driver=cdc_ether, 480M
>     |__ Port 2: Dev 7, If 4, Class=CDC Data, Driver=cdc_ether, 480M
>
> I've not been able to get the cdc_ether portion working yet, although
> I am hopeful.  If both ECM and "option" serial interfaces are
> available, how does ModemManager choose between them?

MM doesn't have any implementation yet to handle ECM interfaces in
Telit modems, but that would definitely be preferred over PPP in a
TTY.

Regarding the patch itself, you shouldn't add the regex to the primary
port. You should run mm_base_modem_peek_data_ports() and add the regex
to all data ports that are TTYs (MM_IS_PORT_SERIAL()). But as said, I
would totally prefer to have this solved somehow without needing to
detect the PPP stream, because it is pppd the only one who should be
touching that (MM yields the control of the TTY to pppd as soon as the
port is in data mode).

-- 
Aleksander
https://aleksander.es