Supported devices

[Igor Almeida]

Hi,

On 01/13/2014 01:50 PM, Aleksander Morgado wrote:
> Hey,
>
>>
>> As well i wanted to ask about cdc-wdm,  qmi_wwan device drivers since i do
>> not find much information about it. On one blog i can read: " This protocol
>> is easily accessible in recent enough Linux kernels (>= 3.4), through the
>> cdc-wdm and qmi_wwan drivers. Once these drivers are in place and the modem
>> gets plugged in, the kernel will expose a new /dev/cdc-wdm device which can
>> talk QMI, along with a wwan interface associated to each QMI port."
>>
>> But if i plug in my Samsung Galaxy S4 i just can see /dev/ttyACM0. Is there
>> a way to install/adapt those device drivers for the Galaxy Android Phone or
>> is this currently not supported? I'm assuming that the latest Snapdragon
>> processors are using QMI is well.
>>
>
> Android, even if using kernel 3.4, doesn't use the upstream qmi_wwan
> driver to handle the QMI protocol internally. The QMI-based Android
> RIL layer will end up using Google's own version of the original
> Qualcomm GobiNet driver, which may actually even use shared memory for
> the QMI protocol instead of a character device in /dev.
>
In my Nexus 4 (LG E960) I do see character devices
/dev/{qmi0,qmi1,qmi2,smd_cxm_qmi} which *may* be usable, though I
have not tried to do anything with them since libqmi requires glib and
there wasn't one readily available in the android toolchain/libs.

I have since found [1] and think it could work.

Of course, this approach requires cross-compiling and using 'adb shell'
to run the cli program, since you won't be able to see the modem directly
from your PC.

[1] http://qinchuan.me/article.php?id=62

> Another thing is how the Android phone is exposed in your PC when the
> phone is plugged in. Android will not expose any QMI device or the
> like to your PC, and you'll likely just get a net interface that you
> can use to share the mobile connection of your phone.
>
> If you want to play with libqmi in your Linux-based system, better use
> a plain modem dongle, like the Huawei one you suggested.
>
> Cheers!
>

-- 
Igor Almeida