Make the "clock valid" control a global control instead of a mixer so that it doesn't appear in mixer applications.
Additionally, remove the check for writeability prohibited by spec, and Use common code to read the control value.
Tested with a UAC2 Audio device that presents a clock validity control. The control still shows up in /proc usbmixer but not in alsamixer.
Signed-off-by: Andrew Chant achant@google.com --- sound/usb/mixer.c | 34 +++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 15 deletions(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 3db4185a5f96..162c10f10dd0 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -1235,8 +1235,8 @@ static int mixer_ctl_feature_put(struct snd_kcontrol *kcontrol, return changed; }
-/* get the current value from a mixer element */ -static int mixer_ctl_connector_get(struct snd_kcontrol *kcontrol, +/* get the boolean value from the master channel of a UAC control */ +static int mixer_ctl_master_bool_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct usb_mixer_elem_info *cval = kcontrol->private_data; @@ -1267,13 +1267,16 @@ static const struct snd_kcontrol_new usb_feature_unit_ctl_ro = { .put = NULL, };
-/* A UAC connector mixer control */ -static struct snd_kcontrol_new usb_connector_ctl_ro = { +/* + * A control which shows the boolean value from reading a UAC control on + * the master channel. + */ +static struct snd_kcontrol_new usb_bool_master_control_ctl_ro = { .iface = SNDRV_CTL_ELEM_IFACE_CARD, .name = "", /* will be filled later manually */ .access = SNDRV_CTL_ELEM_ACCESS_READ, .info = snd_ctl_boolean_mono_info, - .get = mixer_ctl_connector_get, + .get = mixer_ctl_master_bool_get, .put = NULL, };
@@ -1520,13 +1523,18 @@ static void build_connector_control(struct mixer_build *state, if (!cval) return; snd_usb_mixer_elem_init_std(&cval->head, state->mixer, term->id); + /* + * The first byte from reading the UAC2_TE_CONNECTOR control returns the + * number of channels connected. This boolean ctl will simply report + * if any channels are connected or not. + * (Audio20_final.pdf Table 5-10: Connector Control CUR Parameter Block) + */ cval->control = UAC2_TE_CONNECTOR; cval->val_type = USB_MIXER_BOOLEAN; - cval->channels = term->channels; - cval->cmask = term->chconfig; + cval->channels = 1; // only report boolean connected-or-not. cval->min = 0; cval->max = 1; - kctl = snd_ctl_new1(&usb_connector_ctl_ro, cval); + kctl = snd_ctl_new1(&usb_bool_master_control_ctl_ro, cval); if (!kctl) { usb_audio_err(state->chip, "cannot malloc kcontrol\n"); kfree(cval); @@ -1577,13 +1585,9 @@ static int parse_clock_source_unit(struct mixer_build *state, int unitid, cval->val_type = USB_MIXER_BOOLEAN; cval->control = UAC2_CS_CONTROL_CLOCK_VALID;
- if (uac_v2v3_control_is_writeable(hdr->bmControls, - UAC2_CS_CONTROL_CLOCK_VALID)) - kctl = snd_ctl_new1(&usb_feature_unit_ctl, cval); - else { - cval->master_readonly = 1; - kctl = snd_ctl_new1(&usb_feature_unit_ctl_ro, cval); - } + cval->master_readonly = 1; + /* From UAC2 5.2.5.1.2 "Only the get request is supported." */ + kctl = snd_ctl_new1(&usb_bool_master_control_ctl_ro, cval);
if (!kctl) { kfree(cval);