ALSA: ASoC: Add support for generic DAPM register modifier widget

This generic register modifier widget is for updating multiple codec
register bits at once when the widget changes its power state.

Signed-off-by: Jarkko Nikula <jarkko.nikula@nokia.com>
Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index 728f3ac..2536382 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -443,6 +443,25 @@
 }
 
 /*
+ * Handler for generic register modifier widget.
+ */
+int dapm_reg_event(struct snd_soc_dapm_widget *w,
+		   struct snd_kcontrol *kcontrol, int event)
+{
+	unsigned int val;
+
+	if (SND_SOC_DAPM_EVENT_ON(event))
+		val = w->on_val;
+	else
+		val = w->off_val;
+
+	snd_soc_update_bits(w->codec, -(w->reg + 1),
+			    w->mask << w->shift, val << w->shift);
+
+	return 0;
+}
+
+/*
  * Scan each dapm widget for complete audio path.
  * A complete path is a route that has valid endpoints i.e.:-
  *