regcache: Introduce the index parsing API by stride order

Here introduces regcache_get_index_by_order() for regmap cache,
which uses the register stride order and bit rotation, to improve
the performance.

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

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index c22b04b2ca17..5c79526245c2 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -273,4 +273,10 @@ static inline unsigned int regmap_get_offset(const struct regmap *map,
                 return index * map->reg_stride;
 }
 
+static inline unsigned int regcache_get_index_by_order(const struct regmap *map,
+                                                       unsigned int reg)
+{
+        return reg >> map->reg_stride_order;
+}
+
 #endif