ASoC: Allow CODECs to flag invalid registers

This helps CODECs with sparse register maps work better with the
register cache display interface.

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

1 files changed, 3 insertions, 0 deletions

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 5eabb7117608..fb8d7a766155 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -1156,6 +1156,9 @@ static ssize_t soc_codec_reg_show(struct snd_soc_codec *codec, char *buf)
 
         count += sprintf(buf, "%s registers\n", codec->name);
         for (i = 0; i < codec->reg_cache_size; i += step) {
+                if (codec->readable_register && !codec->readable_register(i))
+                        continue;
+
                 count += sprintf(buf + count, "%2x: ", i);
                 if (count >= PAGE_SIZE - 1)
                         break;