ASoC: Allow pins to be force enabled

Allow pins to be forced on regardless of their power state. This is
intended for use with microphone bias supplies which need to be
enabled in order to support microphone detection - in systems without
appropriate hardware leaving the microphone unbiased when not in use
saves power.

The force done at power check time in order to avoid disrupting other
power detection logic.

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

1 files changed, 34 insertions, 1 deletions

diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index 86ded22e36af..bbb2135a0b21 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -979,7 +979,10 @@ static int dapm_power_widgets(struct snd_soc_codec *codec, int event)
 				break;
 
 			default:
-				power = w->power_check(w);
+				if (!w->force)
+					power = w->power_check(w);
+				else
+					power = 1;
 				if (power)
 					sys_power = 1;
 				break;
@@ -2134,6 +2137,36 @@ int snd_soc_dapm_enable_pin(struct snd_soc_codec *codec, const char *pin)
 EXPORT_SYMBOL_GPL(snd_soc_dapm_enable_pin);
 
 /**
+ * snd_soc_dapm_force_enable_pin - force a pin to be enabled
+ * @codec: SoC codec
+ * @pin: pin name
+ *
+ * Enables input/output pin regardless of any other state.  This is
+ * intended for use with microphone bias supplies used in microphone
+ * jack detection.
+ *
+ * NOTE: snd_soc_dapm_sync() needs to be called after this for DAPM to
+ * do any widget power switching.
+ */
+int snd_soc_dapm_force_enable_pin(struct snd_soc_codec *codec, const char *pin)
+{
+	struct snd_soc_dapm_widget *w;
+
+	list_for_each_entry(w, &codec->dapm_widgets, list) {
+		if (!strcmp(w->name, pin)) {
+			pr_debug("dapm: %s: pin %s\n", codec->name, pin);
+			w->connected = 1;
+			w->force = 1;
+			return 0;
+		}
+	}
+
+	pr_err("dapm: %s: configuring unknown pin %s\n", codec->name, pin);
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(snd_soc_dapm_force_enable_pin);
+
+/**
  * snd_soc_dapm_disable_pin - disable pin.
  * @codec: SoC codec
  * @pin: pin name