[ALSA] hda-codec - Fix STAC922x capture boost level

STAC922x provides the capture boost level up to 4, but actually it
works only up to 2.  Since the range of the mixer is automatically
defined from amp-capability bits, we need to override the value
beforehand.  snd_hda_override_amp_caps() is introduced for this
purpose.
The function patch_stac922x() calls this for NID 0x12 (Mux Capture
Volume).  This should fix another recording problem on Intel Macs.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

sound/pci/hda/hda_codec.c

@@ -713,6 +713,19 @@ static u32 query_amp_caps(struct hda_codec *codec, hda_nid_t nid, int direction)
 	return info->amp_caps;
 }
 
+int snd_hda_override_amp_caps(struct hda_codec *codec, hda_nid_t nid, int dir,
+			      unsigned int caps)
+{
+	struct hda_amp_info *info;
+
+	info = get_alloc_amp_hash(codec, HDA_HASH_KEY(nid, dir, 0));
+	if (!info)
+		return -EINVAL;
+	info->amp_caps = caps;
+	info->status |= INFO_AMP_CAPS;
+	return 0;
+}
+
 /*
  * read the current volume to info
  * if the cache exists, read the cache value.

sound/pci/hda/hda_local.h

@@ -277,5 +277,7 @@ static inline u32 get_wcaps(struct hda_codec *codec, hda_nid_t nid)
 	return codec->wcaps[nid - codec->start_nid];
 }
 
+int snd_hda_override_amp_caps(struct hda_codec *codec, hda_nid_t nid, int dir,
+			      unsigned int caps);
 
 #endif /* __SOUND_HDA_LOCAL_H */

sound/pci/hda/patch_sigmatel.c

@@ -2159,6 +2159,13 @@ static int patch_stac927x(struct hda_codec *codec)
 
 	codec->patch_ops = stac92xx_patch_ops;
 
+	/* Fix Mux capture level; max to 2 */
+	snd_hda_override_amp_caps(codec, 0x12, HDA_OUTPUT,
+				  (0 << AC_AMPCAP_OFFSET_SHIFT) |
+				  (2 << AC_AMPCAP_NUM_STEPS_SHIFT) |
+				  (0x27 << AC_AMPCAP_STEP_SIZE_SHIFT) |
+				  (0 << AC_AMPCAP_MUTE_SHIFT));
+
 	return 0;
 }