[ALSA] ac97: YMF743 missing controls support (2/2)

These patches enable a few YMF743 controls (Tone/3D/IEC958) that won't
be detected with the current version of ALSA.
The second one contains following changes:
- A chip-specific SPDIF support for YMF743 (It doesn't have AC97
 standard SPDIF registers seen on YMF753).
- The implementation for 'IEC958 Playback Source' and 'IEC958 Mute'
 are identical to the ones for YMF753. But there is no 'IEC958 Output
 Pin' for YMF743.

Signed-off-by: Keita Maehara <maehara@debian.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/sound/pci/ac97/ac97_proc.c b/sound/pci/ac97/ac97_proc.c
index a3fdd7d..f547986 100644
--- a/sound/pci/ac97/ac97_proc.c
+++ b/sound/pci/ac97/ac97_proc.c
@@ -236,10 +236,14 @@
 		val = snd_ac97_read(ac97, AC97_PCM_MIC_ADC_RATE);
 		snd_iprintf(buffer, "PCM MIC ADC      : %iHz\n", val);
 	}
-	if ((ext & AC97_EI_SPDIF) || (ac97->flags & AC97_CS_SPDIF)) {
+	if ((ext & AC97_EI_SPDIF) || (ac97->flags & AC97_CS_SPDIF) ||
+	    (ac97->id == AC97_ID_YMF743)) {
 	        if (ac97->flags & AC97_CS_SPDIF)
 			val = snd_ac97_read(ac97, AC97_CSR_SPDIF);
-		else
+		else if (ac97->id == AC97_ID_YMF743) {
+			val = snd_ac97_read(ac97, AC97_YMF7X3_DIT_CTRL);
+			val = 0x2000 | (val & 0xff00) >> 4 | (val & 0x38) >> 2;
+		} else
 			val = snd_ac97_read(ac97, AC97_SPDIF);
 
 		snd_iprintf(buffer, "SPDIF Control    :%s%s%s%s Category=0x%x Generation=%i%s%s%s\n",