Need a clarification regarding I2C bus frequency in FreeBSD

[Rajesh Kumar]

Hi,

I am trying to use the I2C designware controller driver available in
FreeBSD (ig4_iic.c) in our boards.

Is there a clean way, I can set the I2C bus frequency from the controller
driver itself, rather than using device hints, FDT, tunables etc.,
Something like, if the driver is loaded for our boards (identified using
the PCI or ACPI ID's), then the frequency of the I2C bus needs to be
hardcoded from driver itself. This is to avoid additional configs from the
config file.

I tried adding a new interface "iicbus_set_frequency" (in line with
iicbus_get_frequency) and tried calling that from the ig4 driver after the
"iicbus" child is added.  But, iicbus instance is created only after ig4
driver is loaded. So, calling iicbus_set_frequency after child addition
leads to system panic (as there is no iicbus softc at this point).

Let me know if you need any details.

Thanks,
Rajesh.