mfd: Enable rbtree cache for wm831x devices

Most useful with the regulators where we're doing a lot of read/modify/write
updates in potentially performance critical paths.  Providing some defaults
would make this slightly better but this is a win right now.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/mfd/wm831x-core.c b/drivers/mfd/wm831x-core.c
index e758c89ac5bb..0a2b8d41a702 100644
--- a/drivers/mfd/wm831x-core.c
+++ b/drivers/mfd/wm831x-core.c
@@ -1602,6 +1602,8 @@ struct regmap_config wm831x_regmap_config = {
         .reg_bits = 16,
         .val_bits = 16,
 
+        .cache_type = REGCACHE_RBTREE,
+
         .max_register = WM831X_DBE_CHECK_DATA,
         .readable_reg = wm831x_reg_readable,
         .writeable_reg = wm831x_reg_writeable,