ALSA: usb-audio: scarlett2: Add support for the talkback feature

Add support for the talkback feature of the 18i20 Gen 3.

Co-developed-by: Vladimir Sadovnikov <sadko4u@gmail.com>
Signed-off-by: Vladimir Sadovnikov <sadko4u@gmail.com>
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Link: https://lore.kernel.org/r/e39599893a7479c290e1aaec6c79dcee87681b47.1624379707.git.g@b4.vu
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/mixer_scarlett_gen2.c b/sound/usb/mixer_scarlett_gen2.c
index f26ab6c398599f9e518dda0b1c46419784b0791b..fcba682cd422d0b0db7edb1000461a82aff2dee0 100644 (file)
--- a/sound/usb/mixer_scarlett_gen2.c
+++ b/sound/usb/mixer_scarlett_gen2.c
@@ -48,8 +48,8 @@
  * Support for Solo/2i2 Gen 3 added in May 2021 (thanks to Alexander
  * Vorona for 2i2 protocol traces).
  *
- * Support for phantom power, direct monitoring, and speaker switching
- * added in May-June 2021.
+ * Support for phantom power, direct monitoring, speaker switching,
+ * and talkback added in May-June 2021.
  *
  * This ALSA mixer gives access to (model-dependent):
  *  - input, output, mixer-matrix muxes
@@ -57,7 +57,8 @@
  *  - gain/volume/mute controls
  *  - level meters
  *  - line/inst level, pad, and air controls
- *  - phantom power, direct monitor, and speaker switching controls
+ *  - phantom power, direct monitor, speaker switching, and talkback
+ *    controls
  *  - disable/enable MSD mode
  *
  * <ditaa>
@@ -318,6 +319,9 @@ struct scarlett2_device_info {
        /* support for main/alt speaker switching */
        u8 has_speaker_switching;
 
+       /* support for talkback microphone */
+       u8 has_talkback;
+
        /* the number of analogue inputs with a software switchable
         * level control that can be set to line or instrument
         */
@@ -396,6 +400,8 @@ struct scarlett2_data {
        u8 phantom_persistence;
        u8 direct_monitor_switch;
        u8 speaker_switching_switch;
+       u8 talkback_switch;
+       u8 talkback_map[SCARLETT2_OUTPUT_MIX_MAX];
        u8 msd_switch;
        struct snd_kcontrol *sync_ctl;
        struct snd_kcontrol *master_vol_ctl;
@@ -410,6 +416,7 @@ struct scarlett2_data {
        struct snd_kcontrol *mux_ctls[SCARLETT2_MUX_MAX];
        struct snd_kcontrol *direct_monitor_ctl;
        struct snd_kcontrol *speaker_switching_ctl;
+       struct snd_kcontrol *talkback_ctl;
        u8 mux[SCARLETT2_MUX_MAX];
        u8 mix[SCARLETT2_INPUT_MIX_MAX * SCARLETT2_OUTPUT_MIX_MAX];
 };
@@ -764,6 +771,7 @@ static const struct scarlett2_device_info s18i20_gen3_info = {
        .has_mixer = 1,
        .line_out_hw_vol = 1,
        .has_speaker_switching = 1,
+       .has_talkback = 1,
        .level_input_count = 2,
        .pad_input_count = 8,
        .air_input_count = 8,
@@ -923,7 +931,8 @@ enum {
        SCARLETT2_CONFIG_DIRECT_MONITOR = 10,
        SCARLETT2_CONFIG_MONITOR_OTHER_SWITCH = 11,
        SCARLETT2_CONFIG_MONITOR_OTHER_ENABLE = 12,
-       SCARLETT2_CONFIG_COUNT = 13
+       SCARLETT2_CONFIG_TALKBACK_MAP = 13,
+       SCARLETT2_CONFIG_COUNT = 14
 };
 
 /* Location, size, and activation command number for the configuration
@@ -998,6 +1007,9 @@ static const struct scarlett2_config
 
        [SCARLETT2_CONFIG_MONITOR_OTHER_ENABLE] = {
                .offset = 0xa0, .size = 1, .activate = 10 },
+
+       [SCARLETT2_CONFIG_TALKBACK_MAP] = {
+               .offset = 0xb0, .size = 16, .activate = 10 },
 } };
 
 /* proprietary request/response format */
@@ -2361,10 +2373,14 @@ static int scarlett2_update_monitor_other(struct usb_mixer_interface *mixer)
        const struct scarlett2_device_info *info = private->info;
        int err;
 
-       /* monitor_other_enable[0] enables speaker switching */
+       /* monitor_other_enable[0] enables speaker switching
+        * monitor_other_enable[1] enables talkback
+        */
        u8 monitor_other_enable[2];
 
-       /* monitor_other_switch[0] activates the alternate speakers */
+       /* monitor_other_switch[0] activates the alternate speakers
+        * monitor_other_switch[1] activates talkback
+        */
        u8 monitor_other_switch[2];
 
        private->monitor_other_updated = 0;
@@ -2374,6 +2390,9 @@ static int scarlett2_update_monitor_other(struct usb_mixer_interface *mixer)
                        mixer, SCARLETT2_CONFIG_DIRECT_MONITOR,
                        1, &private->direct_monitor_switch);
 
+       /* if it doesn't do speaker switching then it also doesn't do
+        * talkback
+        */
        if (!info->has_speaker_switching)
                return 0;
 
@@ -2394,6 +2413,26 @@ static int scarlett2_update_monitor_other(struct usb_mixer_interface *mixer)
        else
                private->speaker_switching_switch = monitor_other_switch[0] + 1;
 
+       if (info->has_talkback) {
+               const int (*port_count)[SCARLETT2_PORT_DIRNS] =
+                       info->port_count;
+               int num_mixes =
+                       port_count[SCARLETT2_PORT_TYPE_MIX][SCARLETT2_PORT_IN];
+               u16 bitmap;
+               int i;
+
+               if (!monitor_other_enable[1])
+                       private->talkback_switch = 0;
+               else
+                       private->talkback_switch = monitor_other_switch[1] + 1;
+
+               err = scarlett2_usb_get_config(mixer,
+                                              SCARLETT2_CONFIG_TALKBACK_MAP,
+                                              1, &bitmap);
+               for (i = 0; i < num_mixes; i++, bitmap >>= 1)
+                       private->talkback_map[i] = bitmap & 1;
+       }
+
        return 0;
 }
 
@@ -2631,6 +2670,171 @@ static int scarlett2_add_speaker_switch_ctl(
                &private->speaker_switching_ctl);
 }
 
+/*** Talkback and Talkback Map Controls ***/
+
+static int scarlett2_talkback_enum_ctl_info(
+       struct snd_kcontrol *kctl, struct snd_ctl_elem_info *uinfo)
+{
+       static const char *const values[3] = {
+               "Disabled", "Off", "On"
+       };
+
+       return snd_ctl_enum_info(uinfo, 1, 3, values);
+}
+
+static int scarlett2_talkback_enum_ctl_get(
+       struct snd_kcontrol *kctl, struct snd_ctl_elem_value *ucontrol)
+{
+       struct usb_mixer_elem_info *elem = kctl->private_data;
+       struct usb_mixer_interface *mixer = elem->head.mixer;
+       struct scarlett2_data *private = mixer->private_data;
+
+       mutex_lock(&private->data_mutex);
+       if (private->monitor_other_updated)
+               scarlett2_update_monitor_other(mixer);
+       ucontrol->value.enumerated.item[0] = private->talkback_switch;
+       mutex_unlock(&private->data_mutex);
+
+       return 0;
+}
+
+static int scarlett2_talkback_enum_ctl_put(
+       struct snd_kcontrol *kctl, struct snd_ctl_elem_value *ucontrol)
+{
+       struct usb_mixer_elem_info *elem = kctl->private_data;
+       struct usb_mixer_interface *mixer = elem->head.mixer;
+       struct scarlett2_data *private = mixer->private_data;
+
+       int oval, val, err = 0;
+
+       mutex_lock(&private->data_mutex);
+
+       oval = private->talkback_switch;
+       val = min(ucontrol->value.enumerated.item[0], 2U);
+
+       if (oval == val)
+               goto unlock;
+
+       private->talkback_switch = val;
+
+       /* enable/disable talkback */
+       err = scarlett2_usb_set_config(
+               mixer, SCARLETT2_CONFIG_MONITOR_OTHER_ENABLE,
+               1, !!val);
+       if (err < 0)
+               goto unlock;
+
+       /* if talkback is enabled, select main or alt */
+       err = scarlett2_usb_set_config(
+               mixer, SCARLETT2_CONFIG_MONITOR_OTHER_SWITCH,
+               1, val == 2);
+       if (err < 0)
+               goto unlock;
+
+unlock:
+       mutex_unlock(&private->data_mutex);
+       return err;
+}
+
+static const struct snd_kcontrol_new scarlett2_talkback_enum_ctl = {
+       .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+       .name = "",
+       .info = scarlett2_talkback_enum_ctl_info,
+       .get  = scarlett2_talkback_enum_ctl_get,
+       .put  = scarlett2_talkback_enum_ctl_put,
+};
+
+static int scarlett2_talkback_map_ctl_get(
+       struct snd_kcontrol *kctl, struct snd_ctl_elem_value *ucontrol)
+{
+       struct usb_mixer_elem_info *elem = kctl->private_data;
+       struct usb_mixer_interface *mixer = elem->head.mixer;
+       struct scarlett2_data *private = mixer->private_data;
+       int index = elem->control;
+
+       ucontrol->value.integer.value[0] = private->talkback_map[index];
+
+       return 0;
+}
+
+static int scarlett2_talkback_map_ctl_put(
+       struct snd_kcontrol *kctl, struct snd_ctl_elem_value *ucontrol)
+{
+       struct usb_mixer_elem_info *elem = kctl->private_data;
+       struct usb_mixer_interface *mixer = elem->head.mixer;
+       struct scarlett2_data *private = mixer->private_data;
+       const int (*port_count)[SCARLETT2_PORT_DIRNS] =
+               private->info->port_count;
+       int num_mixes = port_count[SCARLETT2_PORT_TYPE_MIX][SCARLETT2_PORT_IN];
+
+       int index = elem->control;
+       int oval, val, err = 0, i;
+       u16 bitmap = 0;
+
+       mutex_lock(&private->data_mutex);
+
+       oval = private->talkback_map[index];
+       val = !!ucontrol->value.integer.value[0];
+
+       if (oval == val)
+               goto unlock;
+
+       private->talkback_map[index] = val;
+
+       for (i = 0; i < num_mixes; i++)
+               bitmap |= private->talkback_map[i] << i;
+
+       /* Send updated bitmap to the device */
+       err = scarlett2_usb_set_config(mixer, SCARLETT2_CONFIG_TALKBACK_MAP,
+                                      0, bitmap);
+       if (err < 0)
+               goto unlock;
+
+unlock:
+       mutex_unlock(&private->data_mutex);
+       return err;
+}
+
+static const struct snd_kcontrol_new scarlett2_talkback_map_ctl = {
+       .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+       .name = "",
+       .info = snd_ctl_boolean_mono_info,
+       .get  = scarlett2_talkback_map_ctl_get,
+       .put  = scarlett2_talkback_map_ctl_put,
+};
+
+static int scarlett2_add_talkback_ctls(
+       struct usb_mixer_interface *mixer)
+{
+       struct scarlett2_data *private = mixer->private_data;
+       const struct scarlett2_device_info *info = private->info;
+       const int (*port_count)[SCARLETT2_PORT_DIRNS] = info->port_count;
+       int num_mixes = port_count[SCARLETT2_PORT_TYPE_MIX][SCARLETT2_PORT_IN];
+       int err, i;
+       char s[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+
+       if (!info->has_talkback)
+               return 0;
+
+       err = scarlett2_add_new_ctl(
+               mixer, &scarlett2_talkback_enum_ctl,
+               0, 1, "Talkback Playback Enum",
+               &private->talkback_ctl);
+       if (err < 0)
+               return err;
+
+       for (i = 0; i < num_mixes; i++) {
+               snprintf(s, sizeof(s),
+                        "Talkback Mix %c Playback Switch", i + 'A');
+               err = scarlett2_add_new_ctl(mixer, &scarlett2_talkback_map_ctl,
+                                           i, 1, s, NULL);
+               if (err < 0)
+                       return err;
+       }
+
+       return 0;
+}
+
 /*** Dim/Mute Controls ***/
 
 static int scarlett2_dim_mute_ctl_get(struct snd_kcontrol *kctl,
@@ -3526,7 +3730,9 @@ static void scarlett2_notify_input_other(
                               &private->phantom_ctls[i]->id);
 }
 
-/* Notify on "monitor other" change (direct monitor, speaker switching) */
+/* Notify on "monitor other" change (direct monitor, speaker
+ * switching, talkback)
+ */
 static void scarlett2_notify_monitor_other(
        struct usb_mixer_interface *mixer)
 {
@@ -3546,6 +3752,10 @@ static void scarlett2_notify_monitor_other(
                snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
                               &private->speaker_switching_ctl->id);
 
+       if (info->has_talkback)
+               snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
+                              &private->talkback_ctl->id);
+
        /* if speaker switching was recently enabled or disabled,
         * invalidate the dim/mute and mux enum controls
         */
@@ -3701,6 +3911,11 @@ static int snd_scarlett_gen2_controls_create(struct usb_mixer_interface *mixer)
        if (err < 0)
                return err;
 
+       /* Create the talkback controls */
+       err = scarlett2_add_talkback_ctls(mixer);
+       if (err < 0)
+               return err;
+
        /* Set up the interrupt polling */
        err = scarlett2_init_notify(mixer);
        if (err < 0)