ASoC: Use BIAS_OFF when idle for wm_hubs devices

This provides a small power saving when audio is inactive.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>

1 files changed, 6 insertions, 0 deletions

diff --git a/sound/soc/codecs/wm_hubs.c b/sound/soc/codecs/wm_hubs.c
index d73c30536a2c..a67319d9ca7e 100644
--- a/sound/soc/codecs/wm_hubs.c
+++ b/sound/soc/codecs/wm_hubs.c
@@ -753,6 +753,12 @@ int wm_hubs_handle_analogue_pdata(struct snd_soc_codec *codec,
                                     WM8993_LINEOUT2_MODE,
                                     WM8993_LINEOUT2_MODE);
 
+        /* If the line outputs are differential then we aren't presenting
+         * VMID as an output and can disable it.
+         */
+        if (lineout1_diff && lineout2_diff)
+                codec->idle_bias_off = 1;
+
         if (lineout1fb)
                 snd_soc_update_bits(codec, WM8993_ADDITIONAL_CONTROL,
                                     WM8993_LINEOUT1_FB, WM8993_LINEOUT1_FB);