Some examples would be:
aha1542=0x330 aha152x=0x330,11,7 tmc8xx=0x330,11
Note: the above are verbose. For an AHA1522, use "aha152x". For an AHA1505, use "aha152x". For a TMC800, use "tmc8xx".
When a parameter has commas, make sure you do not put a space after a comma. If you are supplying parameters on the command line the only spaces on should be after linux and between multiple parameters (eg. linux mcd=0x340,11 bmouse=5).