Hello
I'm interested in WWAN support, mostly for the GPS features and the cool things you can do with them (like a stratum ntp server).
I was told a EM770W doesn't even need a network registration to output NMEA coordinates (http://forum.thinkpads.com/viewtopic.php?f=30&t=114426#p735612) so I got one.
I looked at patch #4056 which enable WWAN for the EC, but it seems to only part of the job: the ACPI table should also contain a GWAN key for thinkpad-acpi
In drivers/platform/x86/thinkpad_acpi.c, you can see different references to WAN:
/* ACPI GWAN/SWAN bits */
TP_ACPI_WANCARD_HWPRESENT = 0x01, /* Wan hw available */
TP_ACPI_WANCARD_RADIOSSW = 0x02, /* Wan radio enabled */
TP_ACPI_WANCARD_RESUMECTRL = 0x04, /* Wan state at resume:
0 = disable, 1 = enable */
In wan_get_status :
if (!acpi_evalf(hkey_handle, &status, "GWAN", "d"))
return -EIO;
Apparently, this last part cause the WWAN card not to be handled by thinkpad-acpi, which would otherwise provide rfkill support (usefull to save power, something I'd like to improve)
In acpi-3.dsl Scope (\_SB.PCI0.LPC.EC.HKEY, I see entries for both GWAN and SWAN, and other things (WGPS, but what does it means???)
I believe similar entries should be added to coreboot asl, but I'm not sure of how integrated they should be. If I understand correctly, following the logic of patch #5242, there should be a conditional statement then some acpigen.
If anyone is willing to submit a patch, I would be happy to test it.
Charles