[Letux-kernel] pyra wwan

H. Nikolaus Schaller hns at goldelico.com
Fri Aug 2 16:50:42 CEST 2019


> Am 02.08.2019 um 16:17 schrieb aTc <atc at k-n-p.org>:
> Hi,
> I got some extra sim cards to play with the modem a bit, but can't really find any docs on how to get a data connection going.
> I found the AT command specification, and the hardware interface description, and from that side everything seems to connect and respond fine, but nothing really for the steps required after that on the linux side of things.
> The letux wwan script also doesn't help here, with just a #todo and it sending a command to get the module voltage in the pyra section.
> It would be nice to know what all these ttyACM and wwan0/1 ethernet ports are for, and how to use them properly.
> Do you have any more docs/sdk stuff from gemalto on this ?

Unfortunatley, there isn't much more than the AT commands. And the 3GPP standards.
The ttyACM ports are for AT commands - some do echo others don't. And some can send unsolicited messages.
Allare more or less running in parallel. They have some predefined purposes "Application", "NMEA", "Modem".

So usually user-space uses some middleware taking care of all the AT commands and talking to the modem though one of the ttyACM ports. Examples of such middleware are FSO and ofono or RIL (Android).

The root/pin, root/dial and root/tam scripts do that with pure shell scripts and show several commands.

There is also https://github.com/akemnade/simple-gsmgui

But this all is for telephony and not data.

There is the root/wwan script and indeed it has only a stub for the Gemalto modem because I didn't find time to finish it and setup data connections myself.

The wwan ports seem to be instantiated automatically by the kernel because the module appears to support some standard-USB protocol. There is no special setup to make that happen. Maybe Ethernet over USB? But I do not know. I think dmesg and maybe /sys reveals something about these network interfaces and which driver is responsible.

So I think it could suffice to ifconfig up and add some routing table to make them work.
Maybe it also needs some AT command to connect in 2G, 3G or 4G data mode. This should be in the list of AT commands.

The general approach should not be extremely different from the OPTION GTM601, just the vendor private AT commands differ.

Hope this helps to move a little forward.


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