If you don't know what type of controller you're using, you can use the pci utility to identify it.
For example:
pci -vvv | less
The output from this command looks something like this:
Class = Mass Storage (IDE)
Vendor ID = 8086h, Intel Corporation
Device ID = 7111h, 82371AB/EB PIIX4 IDE Controller
PCI index = 0h
Class Codes = 010180h
Revision ID = 1h
Bus number = 0
Device number = 4
Function num = 1
Status Reg = 280h
Command Reg = 5h
I/O space access enabled
Memory space access disabled
Bus Master enabled
Special Cycle operations ignored
Memory Write and Invalidate disabled
Palette Snooping disabled
Parity Checking disabled
Data/Address stepping disabled
SERR# driver disabled
Fast back-to-back transactions to different agents disabled
Header type = 0h Single-function
BIST = 0h Build-in-self-test not supported
Latency Timer = 20h
Cache Line Size= 0h
PCI IO Address = d800h length 16 enabled
Max Lat = 0ns
Min Gnt = 0ns
PCI Int Pin = NC
Interrupt line = 0
Device Dependent Registers:
0x40: 07 c0 03 80 00 00 00 00 05 00 02 02 00 00 00 00
0x50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0xA0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0xB0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0xC0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0xD0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0xE0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0xF0: 00 00 00 00 00 00 00 00 30 0f 00 00 00 00 00 00
Find the entry for the device you want to locate and it'll give you the details on the manufacturer/vendor ID and device ID. You may need to search for keywords (e.g., Audio) in order to identify your device.
You can search the manufacturer's website for information, or use the vendor and device IDs to cross-reference with /usr/include/hw/pci_devices.h. You can also search https://www.pcilookup.com/.