ALSA: hda - Add a fake mute feature

Some codecs don't supply the mute amp-capabilities although the lowest
volume gives the mute.  It'd be handy if the parser provides the mute
mixers in such a case.

This patch adds an extension amp-cap bit (which is used only in the
driver) to represent the min volume = mute state.  Also modified the
amp cache code to support the fake mute feature when this bit is set
but the real mute bit is unset.

In addition, conexant cx5051 parser uses this new feature to implement
the missing mute controls.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=42825

Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h
index e9f71dc0d464..f0f1943a4b2c 100644
--- a/sound/pci/hda/hda_codec.h
+++ b/sound/pci/hda/hda_codec.h
@@ -298,6 +298,9 @@ enum {
 #define AC_AMPCAP_MUTE                  (1<<31)    /* mute capable */
 #define AC_AMPCAP_MUTE_SHIFT            31
 
+/* driver-specific amp-caps: using bits 24-30 */
+#define AC_AMPCAP_MIN_MUTE              (1 << 30) /* min-volume = mute */
+
 /* Connection list */
 #define AC_CLIST_LENGTH                 (0x7f<<0)
 #define AC_CLIST_LONG                   (1<<7)