rust: io: support register projections

`IoLoc`s themselves just describe a projection from a region to a
concrete register. Thus, support it in `io_project` macro too. Also,
update methods that operate on `IoLoc` to use I/O projection.

Documentation of `io_project!` is not expanded yet as the example works
better when `register!` type can specify base type. `io_read!` and
`io_write!` gains the ability to operate on registers as corollary of
the capability of `io_project!`. Examples are not added because `read`
and `write` is still preferably used instead.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260901-typed_register-v4-5-5552b1d59525@garyguo.net
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

0 files changed, 0 insertions, 0 deletions