ALSA: usb-audio: Add support for Selector Units in UAC3

This patch add support for Selector Units and Clock Selector Units
defined in the new UAC3 spec.

Selector Units play a really important role in the new UAC3 spec as
Processing Units do not define an on/off switch control anymore.
This forces topology designers to add bypass paths in the topology
to enable/dissable the Processing Units.

Signed-off-by: Jorge Sanjuan <jorge.sanjuan@codethink.co.uk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index ca963e9..a51f232 100644 (file)
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -940,6 +940,19 @@ static int check_input_term(struct mixer_build *state, int id,
 
                                return 0;
                        }
+                       case UAC3_SELECTOR_UNIT:
+                       case UAC3_CLOCK_SELECTOR: {
+                               struct uac_selector_unit_descriptor *d = p1;
+                               /* call recursively to retrieve the channel info */
+                               err = check_input_term(state, d->baSourceID[0], term);
+                               if (err < 0)
+                                       return err;
+                               term->type = d->bDescriptorSubtype << 16; /* virtual type */
+                               term->id = id;
+                               term->name = 0; /* TODO: UAC3 Class-specific strings */
+
+                               return 0;
+                       }
                        default:
                                return -ENODEV;
                        }
@@ -2509,11 +2522,20 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid,
        cval->res = 1;
        cval->initialized = 1;
 
-       if (state->mixer->protocol == UAC_VERSION_1)
+       switch (state->mixer->protocol) {
+       case UAC_VERSION_1:
+       default:
                cval->control = 0;
-       else /* UAC_VERSION_2 */
-               cval->control = (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR) ?
-                       UAC2_CX_CLOCK_SELECTOR : UAC2_SU_SELECTOR;
+               break;
+       case UAC_VERSION_2:
+       case UAC_VERSION_3:
+               if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR ||
+                   desc->bDescriptorSubtype == UAC3_CLOCK_SELECTOR)
+                       cval->control = UAC2_CX_CLOCK_SELECTOR;
+               else /* UAC2/3_SELECTOR_UNIT */
+                       cval->control = UAC2_SU_SELECTOR;
+               break;
+       }
 
        namelist = kmalloc_array(desc->bNrInPins, sizeof(char *), GFP_KERNEL);
        if (!namelist) {
@@ -2555,12 +2577,22 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid,
        len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
        if (!len) {
                /* no mapping ? */
+               switch (state->mixer->protocol) {
+               case UAC_VERSION_1:
+               case UAC_VERSION_2:
+               default:
                /* if iSelector is given, use it */
-               nameid = uac_selector_unit_iSelector(desc);
-               if (nameid)
-                       len = snd_usb_copy_string_desc(state->chip, nameid,
-                                                      kctl->id.name,
-                                                      sizeof(kctl->id.name));
+                       nameid = uac_selector_unit_iSelector(desc);
+                       if (nameid)
+                               len = snd_usb_copy_string_desc(state->chip,
+                                                       nameid, kctl->id.name,
+                                                       sizeof(kctl->id.name));
+                       break;
+               case UAC_VERSION_3:
+                       /* TODO: Class-Specific strings not yet supported */
+                       break;
+               }
+
                /* ... or pick up the terminal name at next */
                if (!len)
                        len = get_term_name(state->chip, &state->oterm,
@@ -2570,7 +2602,8 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid,
                        strlcpy(kctl->id.name, "USB", sizeof(kctl->id.name));
 
                /* and add the proper suffix */
-               if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR)
+               if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR ||
+                   desc->bDescriptorSubtype == UAC3_CLOCK_SELECTOR)
                        append_ctl_name(kctl, " Clock Source");
                else if ((state->oterm.type & 0xff00) == 0x0100)
                        append_ctl_name(kctl, " Capture Source");
@@ -2641,6 +2674,7 @@ static int parse_audio_unit(struct mixer_build *state, int unitid)
                        return parse_audio_mixer_unit(state, unitid, p1);
                case UAC3_CLOCK_SOURCE:
                        return parse_clock_source_unit(state, unitid, p1);
+               case UAC3_SELECTOR_UNIT:
                case UAC3_CLOCK_SELECTOR:
                        return parse_audio_selector_unit(state, unitid, p1);
                case UAC3_FEATURE_UNIT: