ALSA: hda/via - Add beep controls to VIA codecs

My codec has a beep-generating node:

  $ cat /proc/asound/card1/codec#0
  Codec: VIA VT1802
  ...
  Vendor Id: 0x11068446
  Subsystem Id: 0x15587410
  Revision Id: 0x100000
  ...
  Node 0x22 [Beep Generator Widget] wcaps 0x70040c: Mono Amp-Out
    Amp-Out caps: ofs=0x0a, nsteps=0x12, stepsize=0x05, mute=1
    Amp-Out vals:  [0x0a]
    Power states:  D0 D1 D2 D3
    Power: setting=D0, actual=D0
  ...

But I was missing the:

  Control: name=...

entries that I need to manage this widget from alsamixer.  With this
patch (based on the similar Mono Amp-Out handling in
patch_conexant.c), I get a new:

  input: HDA Digital PCBeep as /devices/pci0000:00/0000:00:1b.0/sound/card1/hdaudioC1D0/input15

entry in dmesg and controls to manage that beep:

  $ cat /proc/asound/card1/codec#0 | grep -A5 Beep
  Node 0x22 [Beep Generator Widget] wcaps 0x70040c: Mono Amp-Out
    Control: name="Beep Playback Volume", index=0, device=0
      ControlAmp: chs=1, dir=Out, idx=0, ofs=0
    Control: name="Beep Playback Switch", index=0, device=0
      ControlAmp: chs=1, dir=Out, idx=0, ofs=0
    Amp-Out caps: ofs=0x0a, nsteps=0x12, stepsize=0x05, mute=1
    Amp-Out vals:  [0x12]
    Power states:  D0 D1 D2 D3
    Power: setting=D0, actual=D0

[rebased and modified for the latest tree by tiwai]
Signed-off-by: NW. Trevor King <wking@tremily.us>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/pci/hda/patch_via.c

@@ -107,6 +107,8 @@ struct via_spec {
 	/* work to check hp jack state */
 	int hp_work_active;
 	int vt1708_jack_detect;
+
+	unsigned int beep_amp;
 };
 
 static enum VIA_HDA_CODEC get_codec_type(struct hda_codec *codec);
@@ -266,6 +268,59 @@ static const struct snd_kcontrol_new via_pin_power_ctl_enum[] = {
 	{} /* terminator */
 };
 
+#ifdef CONFIG_SND_HDA_INPUT_BEEP
+static inline void set_beep_amp(struct via_spec *spec, hda_nid_t nid,
+				int idx, int dir)
+{
+	spec->gen.beep_nid = nid;
+	spec->beep_amp = HDA_COMPOSE_AMP_VAL(nid, 1, idx, dir);
+}
+
+/* additional beep mixers; the actual parameters are overwritten at build */
+static const struct snd_kcontrol_new cxt_beep_mixer[] = {
+	HDA_CODEC_VOLUME_MONO("Beep Playback Volume", 0, 1, 0, HDA_OUTPUT),
+	HDA_CODEC_MUTE_BEEP_MONO("Beep Playback Switch", 0, 1, 0, HDA_OUTPUT),
+	{ } /* end */
+};
+
+/* create beep controls if needed */
+static int add_beep_ctls(struct hda_codec *codec)
+{
+	struct via_spec *spec = codec->spec;
+	int err;
+
+	if (spec->beep_amp) {
+		const struct snd_kcontrol_new *knew;
+		for (knew = cxt_beep_mixer; knew->name; knew++) {
+			struct snd_kcontrol *kctl;
+			kctl = snd_ctl_new1(knew, codec);
+			if (!kctl)
+				return -ENOMEM;
+			kctl->private_value = spec->beep_amp;
+			err = snd_hda_ctl_add(codec, 0, kctl);
+			if (err < 0)
+				return err;
+		}
+	}
+	return 0;
+}
+
+static void auto_parse_beep(struct hda_codec *codec)
+{
+	struct via_spec *spec = codec->spec;
+	hda_nid_t nid;
+
+	for_each_hda_codec_node(nid, codec)
+		if (get_wcaps_type(get_wcaps(codec, nid)) == AC_WID_BEEP) {
+			set_beep_amp(spec, nid, 0, HDA_OUTPUT);
+			break;
+		}
+}
+#else
+#define set_beep_amp(spec, nid, idx, dir) /* NOP */
+#define add_beep_ctls(codec)	0
+#define auto_parse_beep(codec)
+#endif
 
 /* check AA path's mute status */
 static bool is_aa_path_mute(struct hda_codec *codec)
@@ -352,6 +407,10 @@ static int via_build_controls(struct hda_codec *codec)
 	if (err < 0)
 		return err;
 
+	err = add_beep_ctls(codec);
+	if (err < 0)
+		return err;
+
 	spec->mixers[spec->num_mixers++] = via_pin_power_ctl_enum;
 
 	for (i = 0; i < spec->num_mixers; i++) {
@@ -512,6 +571,8 @@ static int via_parse_auto_config(struct hda_codec *codec)
 	if (err < 0)
 		return err;
 
+	auto_parse_beep(codec);
+
 	err = snd_hda_gen_parse_auto_config(codec, &spec->gen.autocfg);
 	if (err < 0)
 		return err;