regmap: Support register patch sets

Device manufacturers frequently provide register sequences, usually not
fully documented, to be run at startup in order to provide better defaults
for devices (for example, improving performance in the light of silicon
evaluation). Support such updates by allowing drivers to register update
sets with the core. These updates will be written to the device immediately
and will also be rewritten when the cache is synced.

The assumption is that the reason for resyncing the cache will always be
that the device has been powered off. If this turns out to not be the case
then a separate operation can be provided.

Currently the implementation only allows a single set of updates to be
specified for a device, this could be extended in future.

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

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index eb93921cdd30..860739a8a6dd 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -149,6 +149,9 @@ 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);
 
+int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
+                          int num_regs);
+
 /**
  * Description of an IRQ for the generic regmap irq_chip.
  *