ALSA: usb-audio: scarlett2: Add support for "input-other" notify

Some models allow the level and pad settings to be controlled from the
front-panel of the device. For these, the device will send an
"input-other" notification to prompt the driver to re-read the status
of those settings.

Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Link: https://lore.kernel.org/r/06289a7697455e96b7dbdfd2d384d4b20f8df6e0.1624379707.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 d742c93..06454d4 100644 (file)
--- a/sound/usb/mixer_scarlett_gen2.c
+++ b/sound/usb/mixer_scarlett_gen2.c
@@ -318,6 +318,7 @@ struct scarlett2_data {
        u16 scarlett2_seq;
        u8 sync_updated;
        u8 vol_updated;
+       u8 input_other_updated;
        u8 sync;
        u8 master_vol;
        u8 vol[SCARLETT2_ANALOGUE_MAX];
@@ -331,6 +332,8 @@ struct scarlett2_data {
        struct snd_kcontrol *vol_ctls[SCARLETT2_ANALOGUE_MAX];
        struct snd_kcontrol *mute_ctls[SCARLETT2_ANALOGUE_MAX];
        struct snd_kcontrol *dim_mute_ctls[SCARLETT2_DIM_MUTE_COUNT];
+       struct snd_kcontrol *level_ctls[SCARLETT2_LEVEL_SWITCH_MAX];
+       struct snd_kcontrol *pad_ctls[SCARLETT2_PAD_SWITCH_MAX];
        u8 mux[SCARLETT2_MUX_MAX];
        u8 mix[SCARLETT2_INPUT_MIX_MAX * SCARLETT2_OUTPUT_MIX_MAX];
 };
@@ -723,9 +726,10 @@ static int scarlett2_get_port_start_num(
 /*** USB Interactions ***/
 
 /* Notifications from the interface */
-#define SCARLETT2_USB_NOTIFY_SYNC     0x00000008
-#define SCARLETT2_USB_NOTIFY_DIM_MUTE 0x00200000
-#define SCARLETT2_USB_NOTIFY_MONITOR  0x00400000
+#define SCARLETT2_USB_NOTIFY_SYNC        0x00000008
+#define SCARLETT2_USB_NOTIFY_DIM_MUTE    0x00200000
+#define SCARLETT2_USB_NOTIFY_MONITOR     0x00400000
+#define SCARLETT2_USB_NOTIFY_INPUT_OTHER 0x00800000
 
 /* Commands for sending/receiving requests/responses */
 #define SCARLETT2_USB_CMD_INIT 0
@@ -1745,6 +1749,32 @@ static const struct snd_kcontrol_new scarlett2_sw_hw_enum_ctl = {
 
 /*** Line Level/Instrument Level Switch Controls ***/
 
+static int scarlett2_update_input_other(struct usb_mixer_interface *mixer)
+{
+       struct scarlett2_data *private = mixer->private_data;
+       const struct scarlett2_device_info *info = private->info;
+
+       private->input_other_updated = 0;
+
+       if (info->level_input_count) {
+               int err = scarlett2_usb_get_config(
+                       mixer, SCARLETT2_CONFIG_LEVEL_SWITCH,
+                       info->level_input_count, private->level_switch);
+               if (err < 0)
+                       return err;
+       }
+
+       if (info->pad_input_count) {
+               int err = scarlett2_usb_get_config(
+                       mixer, SCARLETT2_CONFIG_PAD_SWITCH,
+                       info->pad_input_count, private->pad_switch);
+               if (err < 0)
+                       return err;
+       }
+
+       return 0;
+}
+
 static int scarlett2_level_enum_ctl_info(struct snd_kcontrol *kctl,
                                         struct snd_ctl_elem_info *uinfo)
 {
@@ -1759,10 +1789,16 @@ static int scarlett2_level_enum_ctl_get(struct snd_kcontrol *kctl,
                                        struct snd_ctl_elem_value *ucontrol)
 {
        struct usb_mixer_elem_info *elem = kctl->private_data;
-       struct scarlett2_data *private = elem->head.mixer->private_data;
+       struct usb_mixer_interface *mixer = elem->head.mixer;
+       struct scarlett2_data *private = mixer->private_data;
 
+       mutex_lock(&private->data_mutex);
+       if (private->input_other_updated)
+               scarlett2_update_input_other(mixer);
        ucontrol->value.enumerated.item[0] =
                private->level_switch[elem->control];
+       mutex_unlock(&private->data_mutex);
+
        return 0;
 }
 
@@ -1811,10 +1847,16 @@ static int scarlett2_pad_ctl_get(struct snd_kcontrol *kctl,
                                 struct snd_ctl_elem_value *ucontrol)
 {
        struct usb_mixer_elem_info *elem = kctl->private_data;
-       struct scarlett2_data *private = elem->head.mixer->private_data;
+       struct usb_mixer_interface *mixer = elem->head.mixer;
+       struct scarlett2_data *private = mixer->private_data;
 
+       mutex_lock(&private->data_mutex);
+       if (private->input_other_updated)
+               scarlett2_update_input_other(mixer);
        ucontrol->value.integer.value[0] =
                private->pad_switch[elem->control];
+       mutex_unlock(&private->data_mutex);
+
        return 0;
 }
 
@@ -2025,7 +2067,7 @@ static int scarlett2_add_line_in_ctls(struct usb_mixer_interface *mixer)
        for (i = 0; i < info->level_input_count; i++) {
                snprintf(s, sizeof(s), fmt, i + 1, "Level", "Enum");
                err = scarlett2_add_new_ctl(mixer, &scarlett2_level_enum_ctl,
-                                           i, 1, s, NULL);
+                                           i, 1, s, &private->level_ctls[i]);
                if (err < 0)
                        return err;
        }
@@ -2034,7 +2076,7 @@ static int scarlett2_add_line_in_ctls(struct usb_mixer_interface *mixer)
        for (i = 0; i < info->pad_input_count; i++) {
                snprintf(s, sizeof(s), fmt, i + 1, "Pad", "Switch");
                err = scarlett2_add_new_ctl(mixer, &scarlett2_pad_ctl,
-                                           i, 1, s, NULL);
+                                           i, 1, s, &private->pad_ctls[i]);
                if (err < 0)
                        return err;
        }
@@ -2446,25 +2488,9 @@ static int scarlett2_read_configs(struct usb_mixer_interface *mixer)
        struct scarlett2_usb_volume_status volume_status;
        int err, i;
 
-       if (info->level_input_count) {
-               err = scarlett2_usb_get_config(
-                       mixer,
-                       SCARLETT2_CONFIG_LEVEL_SWITCH,
-                       info->level_input_count,
-                       private->level_switch);
-               if (err < 0)
-                       return err;
-       }
-
-       if (info->pad_input_count) {
-               err = scarlett2_usb_get_config(
-                       mixer,
-                       SCARLETT2_CONFIG_PAD_SWITCH,
-                       info->pad_input_count,
-                       private->pad_switch);
-               if (err < 0)
-                       return err;
-       }
+       err = scarlett2_update_input_other(mixer);
+       if (err < 0)
+               return err;
 
        err = scarlett2_update_sync(mixer);
        if (err < 0)
@@ -2578,6 +2604,25 @@ static void scarlett2_notify_dim_mute(
                                       &private->mute_ctls[i]->id);
 }
 
+/* Notify on "input other" change (level/pad) */
+static void scarlett2_notify_input_other(
+       struct usb_mixer_interface *mixer)
+{
+       struct snd_card *card = mixer->chip->card;
+       struct scarlett2_data *private = mixer->private_data;
+       const struct scarlett2_device_info *info = private->info;
+       int i;
+
+       private->input_other_updated = 1;
+
+       for (i = 0; i < info->level_input_count; i++)
+               snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
+                              &private->level_ctls[i]->id);
+       for (i = 0; i < info->pad_input_count; i++)
+               snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
+                              &private->pad_ctls[i]->id);
+}
+
 /* Interrupt callback */
 static void scarlett2_notify(struct urb *urb)
 {
@@ -2596,6 +2641,8 @@ static void scarlett2_notify(struct urb *urb)
                scarlett2_notify_monitor(mixer);
        if (data & SCARLETT2_USB_NOTIFY_DIM_MUTE)
                scarlett2_notify_dim_mute(mixer);
+       if (data & SCARLETT2_USB_NOTIFY_INPUT_OTHER)
+               scarlett2_notify_input_other(mixer);
 
 requeue:
        if (ustatus != -ENOENT &&