ALSA: hda - Add snd_hda_get_default_vref() helper function
Add a new helper function to guess the default VREF pin control bits
for mic in. This can be used to set the pin control value safely
matching with the actual pin capabilities.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 2d9716e..8b8b74a 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -4795,6 +4795,33 @@
}
EXPORT_SYMBOL_HDA(snd_hda_multi_out_analog_cleanup);
+/**
+ * snd_hda_get_default_vref - Get the default (mic) VREF pin bits
+ *
+ * Guess the suitable VREF pin bits to be set as the pin-control value.
+ * Note: the function doesn't set the AC_PINCTL_IN_EN bit.
+ */
+unsigned int snd_hda_get_default_vref(struct hda_codec *codec, hda_nid_t pin)
+{
+ unsigned int pincap;
+ unsigned int oldval;
+ oldval = snd_hda_codec_read(codec, pin, 0,
+ AC_VERB_GET_PIN_WIDGET_CONTROL, 0);
+ pincap = snd_hda_query_pin_caps(codec, pin);
+ pincap = (pincap & AC_PINCAP_VREF) >> AC_PINCAP_VREF_SHIFT;
+ /* Exception: if the default pin setup is vref50, we give it priority */
+ if ((pincap & AC_PINCAP_VREF_80) && oldval != PIN_VREF50)
+ return AC_PINCTL_VREF_80;
+ else if (pincap & AC_PINCAP_VREF_50)
+ return AC_PINCTL_VREF_50;
+ else if (pincap & AC_PINCAP_VREF_100)
+ return AC_PINCTL_VREF_100;
+ else if (pincap & AC_PINCAP_VREF_GRD)
+ return AC_PINCTL_VREF_GRD;
+ return AC_PINCTL_VREF_HIZ;
+}
+EXPORT_SYMBOL_HDA(snd_hda_get_default_vref);
+
int _snd_hda_set_pin_ctl(struct hda_codec *codec, hda_nid_t pin,
unsigned int val, bool cached)
{