Reduced Serial Bus (RSB) is an Allwinner proprietery interface
used to communicate with PMICs and other peripheral ICs.

RSB is a two-wire push-pull serial bus that supports 1 master
device and up to 15 active slave devices.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Reviewed-by: NMark Brown <broonie@kernel.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>