Intel SkyLake ACPI INT3472 not working on Dell Latitude 7450

[Alan Stern]

Dan:

The 6.9 kernel fails to activate the webcam on my new laptop.  Comparing 
dmesg logs with the webcam enabled vs. disabled in the BIOS shows 
that the difference lies in the INT3472 driver.  With the camera 
enabled, the following messages appear:

[    5.128560] int3472-discrete INT3472:01: GPIO type 0x12 unknown; the sensor may not work
[    5.128588] int3472-discrete INT3472:01: cannot find GPIO chip INTC10D1:00, deferring
[    5.135938] int3472-discrete INT3472:01: GPIO type 0x12 unknown; the sensor may not work
[    5.135960] int3472-discrete INT3472:01: cannot find GPIO chip INTC10D1:00, deferring
[    5.141230] int3472-discrete INT3472:0c: GPIO type 0x12 unknown; the sensor may not work
[    5.141243] int3472-discrete INT3472:0c: unknown \_SB.GPI0 pin number mismatch _DSM 17 resource 369
[    5.141245] int3472-discrete INT3472:0c: GPIO type 0x02 unknown; the sensor may not work
[    5.148382] int3472-discrete INT3472:01: GPIO type 0x12 unknown; the sensor may not work
[    5.148413] int3472-discrete INT3472:01: cannot find GPIO chip INTC10D1:00, deferring
... many repeats ...
[   17.421707] platform INT3472:01: deferred probe pending: int3472-discrete: Failed to get GPIO

Can you say what's needed to get this working, or suggest a more 
appropriate person to ask?

Thanks,

Alan Stern