regmap: Track if the register cache is dirty and suppress unneeded syncs

Allow drivers to optimise out the register cache sync if they didn't need
to do one. If the hardware is desynced from the register cache (by power
loss for example) then the driver should call regcache_mark_dirty() to
let the core know about this.

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

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 690276a642cf..32043a9749e6 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -143,5 +143,6 @@ int regmap_update_bits(struct regmap *map, unsigned int reg,
 int regcache_sync(struct regmap *map);
 void regcache_cache_only(struct regmap *map, bool enable);
 void regcache_cache_bypass(struct regmap *map, bool enable);
+void regcache_mark_dirty(struct regmap *map);
 
 #endif