regmap: Implement regcache_cache_bypass helper function

Ensure we've got a function so users can enable/disable the
cache bypass option.

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

2 files changed, 20 insertions, 0 deletions

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 5dbc5076267e..876622453cd8 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -286,6 +286,25 @@ void regcache_cache_only(struct regmap *map, bool enable)
 }
 EXPORT_SYMBOL_GPL(regcache_cache_only);
 
+/**
+ * regcache_cache_bypass: Put a register map into cache bypass mode
+ *
+ * @map: map to configure
+ * @cache_only: flag if changes should not be written to the hardware
+ *
+ * When a register map is marked with the cache bypass option, writes
+ * to the register map API will only update the hardware and not the
+ * the cache directly.  This is useful when syncing the cache back to
+ * the hardware.
+ */
+void regcache_cache_bypass(struct regmap *map, bool enable)
+{
+        mutex_lock(&map->lock);
+        map->cache_bypass = enable;
+        mutex_unlock(&map->lock);
+}
+EXPORT_SYMBOL_GPL(regcache_cache_bypass);
+
 bool regcache_set_val(void *base, unsigned int idx,
                       unsigned int val, unsigned int word_size)
 {
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 76ac255a17a5..3daac2d8dc37 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -142,5 +142,6 @@ 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);
 
 #endif