i9195/Qualcomm modem support

Created by: scintill

I've tested with SMS. See f5e8e1f and 72bbfaf for an idea of the changes needed to incorporate this into a similar device. (I'd be willing to help someone port this to their device, if you're familiar with fetching source, compiling, and troubleshooting.) I've been testing with ofono like this:

sudo service ofono start

sudo dbus-send --print-reply --system --dest=org.ofono /gobi_0 org.ofono.Modem.SetProperty string:"Powered" variant:boolean:"true"
sudo dbus-send --print-reply --system --dest=org.ofono /gobi_0 org.ofono.Modem.GetProperties
sudo dbus-send --print-reply --system --dest=org.ofono /gobi_0 org.ofono.Modem.SetProperty string:"Online" variant:boolean:"true"
sudo dbus-send --system --print-reply --dest=org.ofono /gobi_0 org.ofono.MessageManager.SendMessage string:"$PHONE_NUMBER" string:"Hello world! -postmarketOS"

# receive SMS like this (might be spammy if you have other DBus apps):
sudo dbus-monitor --system

What next?

ofono mainline doesn't have support for QMI device voicecalls last I saw, but Sysmocom and Alexander Couzens have patches here that I've successfully used in my Android oFono-based RIL. I have a couple of relevant patches here too. There might be some audio device initialization that needs to be done to route the mic to the phone or something, but it's probably not too hard to figure out since my fully open-source Android stack was working.

I also had data connections working on my Android system, so I anticipate that wouldn't be far away either. We'll need a patch to set something like ofono_modem_set_string(modem, "NetworkInterface", iface_name);, maybe from udev properties. After that, I imagine there's pre-existing things (NetworkManager?) that can take care of a network connection that ofono provides.

And of course, we need a UI to use the phone features... I tried getting Plasma Mobile running on software rendering, but it was extremely slow and crashing or something. Maybe I will try again when I get voicecalls working - I know it has a dialer but I'm not sure about SMS support.

Ping #1054 (closed).