ALSA: hda - Add pcm_playback_hook to hda_gen_spec

The new hook which is called at each PCM playback ops.
It can be used to control the codec-specific power-saving feature in
each codec driver.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_generic.h b/sound/pci/hda/hda_generic.h
index 4c0d9ad..7e84c22 100644
--- a/sound/pci/hda/hda_generic.h
+++ b/sound/pci/hda/hda_generic.h
@@ -69,6 +69,14 @@
 /* active stream id */
 enum { STREAM_MULTI_OUT, STREAM_INDEP_HP };
 
+/* PCM hook action */
+enum {
+	HDA_GEN_PCM_ACT_OPEN,
+	HDA_GEN_PCM_ACT_PREPARE,
+	HDA_GEN_PCM_ACT_CLEANUP,
+	HDA_GEN_PCM_ACT_CLOSE,
+};
+
 struct hda_gen_spec {
 	char stream_name_analog[32];	/* analog PCM stream */
 	const struct hda_pcm_stream *stream_analog_playback;
@@ -191,6 +199,12 @@
 	void (*automute_hook)(struct hda_codec *codec);
 	void (*cap_sync_hook)(struct hda_codec *codec);
 
+	/* PCM playback hook */
+	void (*pcm_playback_hook)(struct hda_pcm_stream *hinfo,
+				  struct hda_codec *codec,
+				  struct snd_pcm_substream *substream,
+				  int action);
+
 	/* automute / autoswitch hooks */
 	void (*hp_automute_hook)(struct hda_codec *codec,
 				 struct hda_jack_tbl *tbl);