Re: SAGEM HiloNC v2 Driver

[Denis Kenzior <denkenz@gmail.com>]

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Hi Marco,

On 03/26/2013 04:07 AM, Freedreamer wrote:
> Hi Everybody,
>
> I'm developing a driver for an embedded system which uses a sagem HiloNC
> v2 and I really should need your help. It's my will to commit everything
> when shall be ready and working.
> First of all I will tell you what i did..I created a plugin sagem.c
> ,added a new Vendor ,  modified makefile & other stuff and seems to work
> properly. I started from calypso driver 'cause the modem is based on a
> Uart and I needed the MUX over that.
> With a very raw/dirty code I was able to use PPP/SMS/net service over
> virtual com.. Very good work dude! :)
>
> Now I would like to clean up my code and get a better understanding of
> the stack. Unfortunately I saw that functions/modules are not always
> commented so I have to ask u a lot of questions (maybe also trivial):
>
> 1) AT cmds sent with "g_at_chat_send" are always async , is that right ?
> Is there any chance to get them sync ?

There is not, we do not want to encourage any sort of blocking behavior 
in the daemon.  Remember there are potentially multiple modems being 
operated on and we do not use threads.

> 2) in enable fnc the modem is powered but The sim is not ready so
> sometimes It hangs up...Do I have to to poll the sim status until is
> ready  , or the driver will do  that by itself ?

oFono never polls for anything.  It is the driver's responsibility to do 
that in the best possible way for the hardware.  Also, powering on the 
modem is separate from the sim being ready.  The general flow is this:

-Enable modem
-Wait for the modem to power on and use ofono_modem_set_powered when 
that happens successfully / fails.
- Figure out if the SIM is inserted and signal using 
ofono_sim_inserted_notify.  Do this step only once the SIM is ready to 
be queried for its PIN status and perform any I/O on SIM files that are 
always accessible (e.g. ICCID)


> 3) could u explain me what should I really do in virtual fnc  set_online
> / post_online ? i tried to stub them but they have not never been called...

oFono has 3 basic states:
- Off
- Radio Off, Sim On
- Radio On, Sim On

set_online turns radio on / off
post_online populates the atoms that are available in radio 'On' state.

> 4) unfortunately this modem has a SIM detection URC but it reset itself
> every time the status changes... so i should call the disable function
> and the enable again in order to have the MUX working... how can i do that?

I'm not following.  Care to elaborate?

> 5) I created and started the MUX as the first thing in enable fnc but is
> that right ? sometimes seems that the modem hangs up if just powered up.
> Put a delay but don't like it very much as a solution...moreover when I
> power up the modem all the URC have been lost 'cause the MUX has not
> been created yet..

That is what we do for most devices with a MUX, put it into MUX state 
right away after basic initialization.  The devices we have can be 
queried for their state in addition to URCs, so it works out very well.

Regards,
-Denis