[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, 1 insertions, 0 deletions

diff --git a/sound/pci/hda/hda_local.h b/sound/pci/hda/hda_local.h
index fafcffe6fc79..51208974c2da 100644
--- a/sound/pci/hda/hda_local.h
+++ b/sound/pci/hda/hda_local.h
@@ -84,6 +84,7 @@ int snd_hda_codec_amp_read(struct hda_codec *codec, hda_nid_t nid, int ch,
                            int direction, int index);
 int snd_hda_codec_amp_update(struct hda_codec *codec, hda_nid_t nid, int ch,
                              int direction, int idx, int mask, int val);
+void snd_hda_codec_resume_amp(struct hda_codec *codec);
 
 /* mono switch binding multiple inputs */
 #define HDA_BIND_MUTE_MONO(xname, nid, channel, indices, direction) \