The most common case is things like bluetooth SCO connections where if there's a baseband you want to clock from the baseband but if there's no baseband (eg, for VoIP calls) you can't do that. Some devices also need to change audio interface configuration depening on things like the number of channels.
Even without any dynamic reconfiguration you also have cases where the sequence people use to power things up is to set the clocking and then configure the audio interface format - even if the audio interface format is always the same you'll still get it being reconfigured the first time you start up.
I see.
BTW I am also planning to add SPI support to this driver. Just want to know if it should be done via reg-map APIs? If yes, then do I need to convert existing I2C stuff too to use reg-map?
TIA!