Which is why it was important to say what signalling was being used on the phone side.
The data sheet doesn’t include the word “asterisk”, so I can’t tell if it includes Asterisk.
BRCM is not a standard Asterisk device technology name, so we are talking about third party hardware and third party drivers. BRCM probably stands for Broadcom, a major supplier of mobile phone chip sets, which also ties in with the fact that this is ARM based. Unfortunately, Broadcom tend to only provide full details under NDA, which can limit the ability to fully use their products in an open source environment.
You need to take this back to the vendor.
The last time I encountered this driver, the thread died off after suggesting contacting the vendor:
I think the relevant conversion is Asterisk internal to analogue, i.e the channel driver interface to the BRCM channel driver. Asterisk is a back to back user agent, and converts from the incoming technology to its internal signalling then back to the outgoing technology. The BRCM driver will not know about the SIP side.