[ALSA] ac97 - Added a codec patch for LM4550

Modules: AC97 Codec

Added a codec patch for LM4550.  It sets up a static volume resolution
table.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/ac97/ac97_codec.c

@@ -150,7 +150,7 @@ static const struct ac97_codec_id snd_ac97_codec_ids[] = {
 { 0x49544561, 0xffffffff, "IT2646E",		patch_it2646,	NULL },
 { 0x4e534300, 0xffffffff, "LM4540,43,45,46,48",	NULL,		NULL }, // only guess --jk
 { 0x4e534331, 0xffffffff, "LM4549",		NULL,		NULL },
-{ 0x4e534350, 0xffffffff, "LM4550",		NULL,		NULL },
+{ 0x4e534350, 0xffffffff, "LM4550",		patch_lm4550,  	NULL }, // volume wrap fix 
 { 0x50534304, 0xffffffff, "UCB1400",		NULL,		NULL },
 { 0x53494c20, 0xffffffe0, "Si3036,8",		mpatch_si3036,	mpatch_si3036, AC97_MODEM_PATCH },
 { 0x54524102, 0xffffffff, "TR28022",		NULL,		NULL },

sound/pci/ac97/ac97_patch.c

@@ -2825,3 +2825,34 @@ int mpatch_si3036(struct snd_ac97 * ac97)
 	snd_ac97_write_cache(ac97, 0x68, 0);
 	return 0;
 }
+
+/*
+ * LM 4550 Codec
+ *
+ * We use a static resolution table since LM4550 codec cannot be
+ * properly autoprobed to determine the resolution via
+ * check_volume_resolution().
+ */
+
+static struct snd_ac97_res_table lm4550_restbl[] = {
+	{ AC97_MASTER, 0x1f1f },
+	{ AC97_HEADPHONE, 0x1f1f },
+	{ AC97_MASTER_MONO, 0x001f },
+	{ AC97_PC_BEEP, 0x001f },	/* LSB is ignored */
+	{ AC97_PHONE, 0x001f },
+	{ AC97_PHONE, 0x001f },
+	{ AC97_MIC, 0x001f },
+	{ AC97_LINE, 0x1f1f },
+	{ AC97_CD, 0x1f1f },
+	{ AC97_VIDEO, 0x1f1f },
+	{ AC97_AUX, 0x1f1f },
+	{ AC97_PCM, 0x1f1f },
+	{ AC97_REC_GAIN, 0x0f0f },
+	{ } /* terminator */
+};
+
+int patch_lm4550(struct snd_ac97 *ac97)
+{
+	ac97->res_table = lm4550_restbl;
+	return 0;
+}

sound/pci/ac97/ac97_patch.h

@@ -59,3 +59,4 @@ int patch_vt1616(struct snd_ac97 * ac97);
 int patch_vt1617a(struct snd_ac97 * ac97);
 int patch_it2646(struct snd_ac97 * ac97);
 int mpatch_si3036(struct snd_ac97 * ac97);
+int patch_lm4550(struct snd_ac97 * ac97);