Helper functions or macros are just as clean as the bitfield syntax. That said, hardware register access is one of those things that is intrinsically tied to a specific platform (and if you target multiple platforms, it will already be behind an abstraction layer), so you can usually know the quirks of how the toolchain for that platform supports bitfields, and use them accordingly. Still more work for people reading the code, though since there are a lot of hidden assumptions behind that deceptively simple "=" than with an explicit mask and shift.