ASoC: Add post-CODEC bias level callback for machine driver

Currently the machine driver can only do bias level configuration before
the CODEC bias level is brought up. This means that the machine cannot do
any configuration which depends on the CODEC bias level being maintained.
Provide a post-CODEC callback which allows the machine driver to do things
like enable the FLL on a CODEC which is brought down to BIAS_OFF when idle.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>

include/sound/soc.h

@@ -632,6 +632,8 @@ struct snd_soc_card {
 	/* callbacks */
 	int (*set_bias_level)(struct snd_soc_card *,
 			      enum snd_soc_bias_level level);
+	int (*set_bias_level_post)(struct snd_soc_card *,
+				   enum snd_soc_bias_level level);
 
 	long pmdown_time;
 

sound/soc/soc-dapm.c

@@ -162,6 +162,10 @@ static int snd_soc_dapm_set_bias_level(struct snd_soc_card *card,
 		else
 			dapm->bias_level = level;
 	}
+	if (ret == 0) {
+		if (card && card->set_bias_level_post)
+			ret = card->set_bias_level_post(card, level);
+	}
 
 	trace_snd_soc_bias_level_done(card, level);