If I understand Aleksandar correctly, the naming is incorrect
because too generic to AVR family, why Sarah only modeled the
Atmel implementation.
Renaming devices such hw/char/avr_usart.c ->
hw/char/atmel_usart.c (similarly with the macros) would be
enough Aleksandar?
Some renaming could help, perhaps not quite like the one above, but
my point (which I find hard to believe I can't explain to you) is
that peripherals inside the chip evolved over time, as starkly
opposed to external peripherals that are set in stone...