Telit LE910-NVG

[Randy Yates]

Hi,

We have a board that is a derivative of the BeagleBone Black. In 
fact it is almost identical with the exception of the addition of
a few components, namely the Telit LE910-NVG cellular module. 

We are running version 4.4 of the linux kernel and the Debian Jesse
distribution. This is somewhat customized build based on Robert C.
Nelson's custom build instructions here: 

  https://eewiki.net/display/linuxonarm/BeagleBone+Black

When the system first boots there are no /dev/ttyUSBzz devices listed
in the device filesystem. I wrote some userland code that performs
the initialization for the Telit module:

  1) controls the regulator on 

  2) wiggles the ON/OFF# line to the module per the timing specified
  in section 4.2 of the Telit LE910 Hardware User Guide. 

After running this code, the 910 enumerates on the USB bus. I see
/dev/ttyUSB0 through /dev/ttyUSB4. I can also connect to /dev/ttyUSB2
and issue AT commands successfully, e.g., "AT+GSN" and receive the
IMEI number back.

Also the result of lsusb looks right:

  root at arm:~# lsusb
  Bus 001 Device 002: ID 1bc7:1201 Telit 
  Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

The qmi_wwan kernel module also appears to be loaded as evidenced
from the lsmod:

  root at arm:~# lsmod
  Module                  Size  Used by
  sg                     25685  0 
  option                 29643  0 
  usb_wwan                9306  1 option
  qmi_wwan               11910  0 
  cdc_wdm                11671  1 qmi_wwan
  uas                    11809  0 
  usbserial              34565  2 option,usb_wwan
  usbnet                 31258  1 qmi_wwan
  mii                     4596  1 usbnet
  usb_f_ecm               9400  1 
  g_ether                 4791  0 
  usb_f_rndis            22035  2 g_ether
  u_ether                11013  3 usb_f_ecm,usb_f_rndis,g_ether
  libcomposite           42737  3 usb_f_ecm,usb_f_rndis,g_ether
  omap_aes               13361  0 
  omap_sham              21319  0 
  snd_soc_davinci_mcasp    15887  0 
  snd_soc_edma            1290  1 snd_soc_davinci_mcasp
  snd_soc_omap            3058  1 snd_soc_davinci_mcasp
  omap_rng                4359  0 
  rng_core                7254  1 omap_rng
  snd_soc_core          155574  3 snd_soc_davinci_mcasp,snd_soc_edma,snd_soc_omap
  snd_pcm_dmaengine       5273  2 snd_soc_core,snd_soc_omap
  snd_pcm                79420  4 snd_soc_davinci_mcasp,snd_soc_core,snd_soc_omap,snd_pcm_dmaengine
  snd_timer              17433  1 snd_pcm
  spi_omap2_mcspi        11203  0 
  snd                    57634  3 snd_soc_core,snd_timer,snd_pcm
  soundcore               7029  1 snd
  evdev                   9907  0 
  uio_pdrv_genirq         3437  0 
  leds_gpio               3420  0 
  uio                     8806  1 uio_pdrv_genirq

We seem to be 90 percent of the way to a working network interface, but
ifconfig still does not list anything other than the standard lo and eth0 
interfaces.

What more do I need to do to get our module to show up as a network interface?
-- 
Randy Yates, DSP/Embedded Firmware Developer
Digital Signal Labs
http://www.digitalsignallabs.com