regmap: flat: Add flat cache type
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>
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 401d191..e22bb80 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -177,5 +177,6 @@
extern struct regcache_ops regcache_rbtree_ops;
extern struct regcache_ops regcache_lzo_ops;
+extern struct regcache_ops regcache_flat_ops;
#endif