ALSA: hda - Add standard channel maps

Although HD-audio allows pair-wise channel configurations, only the
fixed channel positions are used in this version.  In future, this can
be changed and allow user to modify the channel positions.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/hda_codec.c

@@ -3688,6 +3688,36 @@ int /*__devinit*/ snd_hda_build_controls(struct hda_bus *bus)
 }
 EXPORT_SYMBOL_HDA(snd_hda_build_controls);
 
+/*
+ * add standard channel maps if not specified
+ */
+static int add_std_chmaps(struct hda_codec *codec)
+{
+	int i, str, err;
+
+	for (i = 0; i < codec->num_pcms; i++) {
+		for (str = 0; str < 2; str++) {
+			struct snd_pcm *pcm = codec->pcm_info[i].pcm;
+			struct hda_pcm_stream *hinfo =
+				&codec->pcm_info[i].stream[str];
+			struct snd_pcm_chmap *chmap;
+
+			if (codec->pcm_info[i].own_chmap)
+				continue;
+			if (!pcm || !hinfo->substreams)
+				continue;
+			err = snd_pcm_add_chmap_ctls(pcm, str,
+						     snd_pcm_std_chmaps,
+						     hinfo->channels_max,
+						     0, &chmap);
+			if (err < 0)
+				return err;
+			chmap->channel_mask = SND_PCM_CHMAP_MASK_2468;
+		}
+	}
+	return 0;
+}
+
 int snd_hda_codec_build_controls(struct hda_codec *codec)
 {
 	int err = 0;
@@ -3699,6 +3729,12 @@ int snd_hda_codec_build_controls(struct hda_codec *codec)
 		err = codec->patch_ops.build_controls(codec);
 	if (err < 0)
 		return err;
+
+	/* we create chmaps here instead of build_pcms */
+	err = add_std_chmaps(codec);
+	if (err < 0)
+		return err;
+
 	snd_hda_jack_report_sync(codec); /* call at the last init point */
 	return 0;
 }

sound/pci/hda/hda_codec.h

@@ -776,6 +776,7 @@ struct hda_pcm {
 	unsigned int pcm_type;	/* HDA_PCM_TYPE_XXX */
 	int device;		/* device number to assign */
 	struct snd_pcm *pcm;	/* assigned PCM instance */
+	bool own_chmap;		/* codec driver provides own channel maps */
 };
 
 /* codec information */

sound/pci/hda/patch_realtek.c

@@ -2287,6 +2287,8 @@ static int alc_build_pcms(struct hda_codec *codec)
 			p = &alc_pcm_analog_playback;
 		info->stream[SNDRV_PCM_STREAM_PLAYBACK] = *p;
 		info->stream[SNDRV_PCM_STREAM_PLAYBACK].nid = spec->multiout.dac_nids[0];
+		info->stream[SNDRV_PCM_STREAM_PLAYBACK].channels_max =
+			spec->multiout.max_channels;
 	}
 	if (spec->adc_nids) {
 		p = spec->stream_analog_capture;