Telit LE910 V2, cdc_ncm and systemd

[Aleksander Morgado]

Hey,

>> If it comes to implementing the NCM protocol, it's nice to hear that you will guide me :-)
>
> Aleksander gave me some guidance for a similar situation and what you want to do here is going to be very similar to the 'mm-broadband-bearer-cinterion.c' & 'mm-broadband-bearer-huawei.c' files. Basically in the 'mm-broadband-modem..' you'll need to have a way to detect support for Telits's NCM Protocol, such as sending a test read cmd and checking for a certain response. If that cmd if supported you'll set a flag to use in the 'mm-broadband-bearer..' to setup the WWAN connection, or something like that.
>
> On Thu, Nov 8, 2018 at 9:29 AM Stelling2 Carsten <Carsten.Stelling2 at goerlitz.com> wrote:
>>
>> Hi Aleksander,
>>
>> Thank you for your fast reply, and explanation.
>> Meanwhile, I've updated MM to 1.8.2 within my Yocto-Project.
>> Also, thanks for your hint to AT#USBCFG=5 (yes, 5 or 3 should work). I'll give it a try tomorrow.
>>
>> Regarding the NCM protocol, I followed the instructions in Telits's NCM Protocol User Guide.
>>
>> AT+CGDCONT=4,"IP","APN"
>> AT#NCM=2,4,0,"User Name", "Password"
>> Then, I used the output of AT+CGCONTRDP=4, to configure the wwan0 interface manually. It works.
>>
>> If it comes to implementing the NCM protocol, it's nice to hear that you will guide me :-)
>>

Yes, what Matthew said basically :)

In this case, though, we don't need any magic to know whether we're
dealing with the NCM variant of the network interface, as we can query
the kernel driver in use for that specific kernel device, and it'll
say "cdc_ncm". So, when a new bearer object is created in the Telit
modem, we check whether the network interface is NCM, and if it is we
create a new e.g. MMBroadbandBearerTelitNcm object that subclasses the
dial_3gpp() method to send the AT#NCM command and the
get_ip_config_3gpp() to query the static IP settings to use with
AT+CGCONTRDP. Probably the "mbm" plugin or the "option/hso" plugins
would be the best examples of this kind of logic needed.

-- 
Aleksander
https://aleksander.es