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>

1 files changed, 44 insertions, 10 deletions

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index ca963e94ec03..a51f2320a3dd 100644
--- 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: