Tom Deckert wrote:
Hi,
The 3G USBModem I purchase does not work when I plug it
in to Ubuntu Intrepid Ibex. I want it to "just work".
I emailed here, and Ubuntu Forums, and then finally thought
to contact the manufacturer, ZTE.
I told them adding Linux support would be easy, all they needed
to do was provide information about their devices to the Linux
community.
On their support forum, they responded: "What information do you need?"
So, what information do I need? To whom do I need to provide it?
I know:
Model: MF626
VendorID = 0x19d2
ProductID = 0x2000 (Storage)
ProductID = 0x0031 (modem)
A person at the ZTE forums reported the Device Map:
DIAG VID=0x19D2,PID=0x0031 MI=00
NMEA VID=0x19D2,PID=0x0031 MI=01
TCard VID=0x19D2,PID=0x0031 MI=02
Modem VID=0x19D2,PID=0x0031 MI=03
The modem commands are:
AT+ZOPRT=5 - makes the device to stay in online mode
AT+ZCDRUN=8 - disables auto-run
AT+CGDCONT - configures the correct APN profile
These devices look like a modem to Linux. Like a modem
you issue AT commands and use PPP to establish the Internet
link.
That's an illusion of course, since the PPP connection
terminates on the card itself, and the card communicates
with the telco infrastructure using another set of protocols.
You can get a view of that world from the DIAG port, and the
protocol for that port is vendor-specific. Usefully, the DIAG
port will cough up received signal strength information.
The NMEA port is a USB serial device view of an artificial
NMEA device (NMEA is the serial protocol used to network
boat electronics). The NMEA protocol could be used to access
the timing signal of the GSM protocol, or there might be a
full GPS receiver in the USB stick. You'll need to ask, and
you'll need specs on what NMEA "sentences" activate which
features.
The Tcard is your USB storage device. Typically manufacturers are including
these to give distributors a simple way to distribute their driver
software with the device. I've only ever seen one device where this
also held the firmware for the device -- more typically the firmware
is upgraded through the DIAG port.
I'm not sure who's job it is to figure out that when a
MF626 is plugged in, it should ignore the USB Mass Storage
and just set up the modem to run.
You want all of the on-board devices to come up: you just
need to push the IDs into the USB serial driver (there's
module options if you want to experiment prior to coding).
For the modem and NMEA serial devices you want the features
and the AT commands or NMEA sentences to use those features.
Sierra Wireless gives these out in their manuals, and they
are a nice example to provide your manufacturer.
Question: Should I file A) HAL bug report, B)NetworkManager
bug report, C) HAL and NetworkManager bug reports?
D) Something else?
If the serial driver doesn't automatically load, then it needs
IDs added, and this involves udev.
If it does load then it's up to HAL to organise the correct
user-space response. For the GSM modem that's sending a
D-Bus message with the serial device ID, which Network
Manager receives. Later NM understands GSM modems.
Although that sounds a lot of work, copying the XML
HAL configuration from another GSM modem is simple.
As you can see, udev and HAL duplicate some functions,
and there's a move to combine the two.
For the NMEA device, HAL doesn't understand these at all.
Which is a shame, as there's a growing need for applications
to share info from location and time devices. Without
developing all that, ensuring udev loads the USB serial
driver and you can see the sentences in a terminal emulator
is about all which can be done.
The DIAG port will need a driver. From what I've seen to
date, this can be a trivial module layered over USB serial.
The storage works, as it should. Would be worthwhile seeing
if there's a HAL option to hint to the desktop system not
to bring this device to the user's immediate attention
(ie, create desktop icon, but don't open the file manager).
--
Glen Turner <http://www.gdt.id.au/~gdt/>
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