mfd: Put WM8994 into cache only mode when suspending

This is required by the ASoC driver for very low power modes where the
device is fully idle but we want to update controls.

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

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c
index 9b8d1ad28ee1..d3d9d53ca9e3 100644
--- a/drivers/mfd/wm8994-core.c
+++ b/drivers/mfd/wm8994-core.c
@@ -268,6 +268,7 @@ static int wm8994_suspend(struct device *dev)
         wm8994_reg_write(wm8994, WM8994_SOFTWARE_RESET,
                          wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET));
 
+        regcache_cache_only(wm8994->regmap, true);
         regcache_mark_dirty(wm8994->regmap);
 
         wm8994->suspended = true;
@@ -298,6 +299,7 @@ static int wm8994_resume(struct device *dev)
                 return ret;
         }
 
+        regcache_cache_only(wm8994->regmap, false);
         ret = regcache_sync(wm8994->regmap);
         if (ret != 0) {
                 dev_err(dev, "Failed to restore register map: %d\n", ret);