This makes the code slightly more readable and allows for cleaner
addition of functionality in later patches.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

If max_register is unset, regcache_flat_get_index will return 0 and only
memory for 1 unsigned int will be allocated, resulting in writing out
of bounds.

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Here we introduce regcache_flat_get_index(), which using register
stride order and bit rotation, will save some memory spaces for
flat cache. Though this will also lost some access performance,
since the bit rotation is used to get the index of the cache array,
and this could be ingored for memory I/O accessing.

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Replace kzalloc with specialized function kcalloc when the size is
a multiplication of : number * sizeof

Signed-off-by: lixiubo <lixiubo@cmss.chinamobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

If the inlcude headers aren't sorted alphabetically, then the
logical choice is to append new ones, however that creates a
lot of potential for conflicts or duplicates because every change
will then add new includes in the same location.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

While for I2C and SPI devices the overhead of using rbtree for devices with
only one block of registers is negligible the same isn't always going to
be true for MMIO devices where the I/O costs are very much lower. Cater
for these devices by adding a simple flat array type for them where the
lookups are simple array accesses, taking us right back to the original
ASoC cache implementation.

Thanks to Magnus Damm for the discussion which prompted this.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>