[ALSA] hda-codec - introduce command register cache

This patch adds the cache for codec command registers.
snd_hda_codec_write_cache() and snd_hda_sequence_write_cache() do
the write operations with caching, which values can be resumed via
snd_hda_codec_resume_cache().
The patch introduces only the framework, and no codec code is using
this cache yet.  It'll be implemented in the following patch.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 8 insertions, 0 deletions

diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h
index 1a69743160ce..ef94c9122c6d 100644
--- a/sound/pci/hda/hda_codec.h
+++ b/sound/pci/hda/hda_codec.h
@@ -570,6 +570,7 @@ struct hda_codec {
         u32 *wcaps;
 
         struct hda_cache_rec amp_cache; /* cache for amp access */
+        struct hda_cache_rec cmd_cache; /* cache for other commands */
 
         struct mutex spdif_mutex;
         unsigned int spdif_status;      /* IEC958 status bits */
@@ -620,6 +621,13 @@ void snd_hda_sequence_write(struct hda_codec *codec,
 /* unsolicited event */
 int snd_hda_queue_unsol_event(struct hda_bus *bus, u32 res, u32 res_ex);
 
+/* cached write */
+int snd_hda_codec_write_cache(struct hda_codec *codec, hda_nid_t nid,
+                              int direct, unsigned int verb, unsigned int parm);
+void snd_hda_sequence_write_cache(struct hda_codec *codec,
+                                  const struct hda_verb *seq);
+void snd_hda_codec_resume_cache(struct hda_codec *codec);
+
 /*
  * Mixer
  */