ALSA: hda - check supported power states

Add function to check whether power states supported by specific
codec node.
Signed-off-by: Wang Xingchao <xingchao.wang@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/hda_codec.c

@@ -3504,6 +3504,22 @@ void snd_hda_codec_set_power_to_all(struct hda_codec *codec, hda_nid_t fg,
 }
 EXPORT_SYMBOL_HDA(snd_hda_codec_set_power_to_all);
 
+/*
+ *  supported power states check
+ */
+static bool snd_hda_codec_get_supported_ps(struct hda_codec *codec, hda_nid_t fg,
+				unsigned int power_state)
+{
+	int sup = snd_hda_param_read(codec, fg, AC_PAR_POWER_STATE);
+
+	if (sup < 0)
+		return false;
+	if (sup & power_state)
+		return true;
+	else
+		return false;
+}
+
 /*
  * set power state of the codec
  */