regmap: Constify static regmap_bus structs

The only usage of these is to pass their address to __regmap_init() or
__devm_regmap_init(), both which takes pointers to const struct
regmap_bus. Make them const to allow the compiler to put them in
read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20220330214110.36337-1-rikard.falkeborn@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: slimbus: add support to multi read/write

SLIMbus supports upto 16 bytes in value management messages,
so add support to read/writes upto 16 bytes.

This also removes redundant single register reg_read/reg_write.

Also useful for paged register access on SLIMbus interfaced codecs.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: slimbus: allow register offsets up to 16 bits

As per SLIMBus specs Value Elements and Information Elements
address map ranges from 0x000 - 0xFFF.

So allow register addresses up to 16 bits

Fixes: 7d6f7fb053ad ("regmap: add SLIMbus support")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: add SLIMbus support

This patch adds support to read/write SLIMbus value elements.
Currently it only supports byte read/write. Adding this support in
regmap would give codec drivers more flexibility when there are more
than 2 control interfaces like SLIMbus, i2c.

Without this patch each codec driver has to directly call SLIMbus value
element apis, and this could would get messy once we want to add i2c
interface to it.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviwed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>