[ALSA] hda-codec - Add virtual master controls

Add master controls using vmaster to codecs that have no real hardware
master volume registers.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

1 files changed, 60 insertions, 0 deletions

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index a2b40dc372c9..caacc58c0813 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -1012,6 +1012,66 @@ int snd_hda_mixer_amp_tlv(struct snd_kcontrol *kcontrol, int op_flag,
         return 0;
 }
 
+/*
+ * set (static) TLV for virtual master volume; recalculated as max 0dB
+ */
+void snd_hda_set_vmaster_tlv(struct hda_codec *codec, hda_nid_t nid, int dir,
+                             unsigned int *tlv)
+{
+        u32 caps;
+        int nums, step;
+
+        caps = query_amp_caps(codec, nid, dir);
+        nums = (caps & AC_AMPCAP_NUM_STEPS) >> AC_AMPCAP_NUM_STEPS_SHIFT;
+        step = (caps & AC_AMPCAP_STEP_SIZE) >> AC_AMPCAP_STEP_SIZE_SHIFT;
+        step = (step + 1) * 25;
+        tlv[0] = SNDRV_CTL_TLVT_DB_SCALE;
+        tlv[1] = 2 * sizeof(unsigned int);
+        tlv[2] = -nums * step;
+        tlv[3] = step;
+}
+
+/* find a mixer control element with the given name */
+struct snd_kcontrol *snd_hda_find_mixer_ctl(struct hda_codec *codec,
+                                            const char *name)
+{
+        struct snd_ctl_elem_id id;
+        memset(&id, 0, sizeof(id));
+        id.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+        strcpy(id.name, name);
+        return snd_ctl_find_id(codec->bus->card, &id);
+}
+
+/* create a virtual master control and add slaves */
+int snd_hda_add_vmaster(struct hda_codec *codec, char *name,
+                        unsigned int *tlv, const char **slaves)
+{
+        struct snd_kcontrol *kctl;
+        const char **s;
+        int err;
+
+        kctl = snd_ctl_make_virtual_master(name, tlv);
+        if (!kctl)
+                return -ENOMEM;
+        err = snd_ctl_add(codec->bus->card, kctl);
+        if (err < 0)
+                return err;
+        
+        for (s = slaves; *s; s++) {
+                struct snd_kcontrol *sctl;
+
+                sctl = snd_hda_find_mixer_ctl(codec, *s);
+                if (!sctl) {
+                        snd_printdd("Cannot find slave %s, skipped\n", *s);
+                        continue;
+                }
+                err = snd_ctl_add_slave(kctl, sctl);
+                if (err < 0)
+                        return err;
+        }
+        return 0;
+}
+
 /* switch */
 int snd_hda_mixer_amp_switch_info(struct snd_kcontrol *kcontrol,
                                   struct snd_ctl_elem_info *uinfo)