ASoC: fsl_ssi: mark some registers precious

Mark some registers precious since their
reads have side effects (like clearing flags).

Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index cc22354d7758e687601a1ac91826558da55190a5..40dfd8a3648408a2cc76bb6e4c4c3872c8e28ac3 100644 (file)
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -157,6 +157,21 @@ static bool fsl_ssi_volatile_reg(struct device *dev, unsigned int reg)
        }
 }
 
+static bool fsl_ssi_precious_reg(struct device *dev, unsigned int reg)
+{
+       switch (reg) {
+       case CCSR_SSI_SRX0:
+       case CCSR_SSI_SRX1:
+       case CCSR_SSI_SISR:
+       case CCSR_SSI_SACADD:
+       case CCSR_SSI_SACDAT:
+       case CCSR_SSI_SATAG:
+               return true;
+       default:
+               return false;
+       }
+}
+
 static bool fsl_ssi_writeable_reg(struct device *dev, unsigned int reg)
 {
        switch (reg) {
@@ -179,6 +194,7 @@ static const struct regmap_config fsl_ssi_regconfig = {
        .num_reg_defaults = ARRAY_SIZE(fsl_ssi_reg_defaults),
        .readable_reg = fsl_ssi_readable_reg,
        .volatile_reg = fsl_ssi_volatile_reg,
+       .precious_reg = fsl_ssi_precious_reg,
        .writeable_reg = fsl_ssi_writeable_reg,
        .cache_type = REGCACHE_RBTREE,
 };