The maple tree register cache is based on a much more modern data structure
than the rbtree cache and makes optimisation choices which are probably
more appropriate for modern systems than those made by the rbtree cache. In
v6.5 it has also acquired the ability to generate multi-register writes in
sync operations, bringing performance up to parity with the rbtree cache
there.

Update the cs47l92 driver to use the more modern data structure.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230713-mfd-cirrus-maple-v1-6-16dacae402a8@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>

GPL-2.0-only is the preferred way of expressing v2 of the GPL, so switch
to that. Remove some redundant copyright notices and correct some
instances where the wrong comment type has been used in header files.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

This patch adds all the core support and defines for the Cirrus
Logic CS42L92, CS47L92 and CS47L93 smart audio CODECs.

Registers or fields are named MADERA_* if it is part of the
common hardware platform and does not conflict with any other
Madera codecs. It is named CS47L15_* if it is unique to CS47L15
and conflicts with definitions on other codecs.

Signed-off-by: Stuart Henderson <stuarth@opensource.cirrus.com>
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>