ALSA: scarlett2: Add Vocaster speaker/headphone mute controls

Add support for the speaker and headphone mute controls on Focusrite
Vocaster interfaces. Unlike other Focusrite interfaces, these mute
controls are per-output, not per-channel.

Signed-off-by: Geoffrey D. Bennett <[e-mail]>
Link: https://patch.msgid.link/aLm2Dy6+O/[e-mail]
Signed-off-by: Takashi Iwai <[e-mail]>

sound/usb/mixer_scarlett2.c

···
  *   - Solo/2i2/4i4 Gen 4
  *   - Clarett 2Pre/4Pre/8Pre USB
  *   - Clarett+ 2Pre/4Pre/8Pre
+ *   - Vocaster One/Two
  *
- *   Copyright (c) 2018-2024 by Geoffrey D. Bennett <g at b4.vu>
+ *   Copyright (c) 2018-2025 by Geoffrey D. Bennett <g at b4.vu>
  *   Copyright (c) 2020-2021 by Vladimir Sadovnikov <[e-mail]>
  *   Copyright (c) 2022 by Christian Colglazier <[e-mail]>
  *
···
  * Support for Scarlett Solo/2i2/4i4 Gen 4 added in Dec 2023 (thanks
  * to many LinuxMusicians people and to Focusrite for hardware
  * donations).
+ *
+ * Support for Vocaster One and Two added in Mar 2024 (thanks to many
+ * LinuxMusicians people and to Focusrite for hardware donations).
  *
  * This ALSA mixer gives access to (model-dependent):
  *  - input, output, mixer-matrix muxes
···
 	"Mute Playback Switch", "Dim Playback Switch"
 };
 
+/* Vocaster One speaker/headphone mute names */
+static const char *const vocaster_one_sp_hp_mute_names[] = {
+	"Speaker Mute Playback Switch",
+	"Headphones Mute Playback Switch",
+	NULL
+};
+
+/* Vocaster Two speaker/headphone mute names */
+static const char *const vocaster_two_sp_hp_mute_names[] = {
+	"Speaker Mute Playback Switch",
+	"Headphones 1 Mute Playback Switch",
+	"Headphones 2 Mute Playback Switch",
+	NULL
+};
+
 /* The autogain_status is set based on the autogain_switch and
  * raw_autogain_status values.
  *
···
 	SCARLETT2_CONFIG_DIRECT_MONITOR_GAIN,
 	SCARLETT2_CONFIG_BLUETOOTH_VOLUME,
 	SCARLETT2_CONFIG_SPDIF_MODE,
+	SCARLETT2_CONFIG_SP_HP_MUTE,
 	SCARLETT2_CONFIG_COUNT
 };
 
···
 
 		[SCARLETT2_CONFIG_BLUETOOTH_VOLUME] = {
 			.offset = 0xbf, .size = 8, .activate = 28 },
+
+		[SCARLETT2_CONFIG_SP_HP_MUTE] = {
+			.offset = 0xab, .size = 8, .activate = 10 },
 	}
 };
 
···
 	/* additional description for the line out volume controls */
 	const char * const line_out_descrs[SCARLETT2_ANALOGUE_MAX];
 
+	/* Vocaster speaker/headphone mute control names */
+	const char * const *sp_hp_mute_names;
+
 	/* number of sources/destinations of each port type */
 	const int port_count[SCARLETT2_PORT_TYPE_COUNT][SCARLETT2_PORT_DIRNS];
 
···
 	u8 level_switch[SCARLETT2_LEVEL_SWITCH_MAX];
 	u8 pad_switch[SCARLETT2_PAD_SWITCH_MAX];
 	u8 dim_mute[SCARLETT2_DIM_MUTE_COUNT];
+	u8 sp_hp_mute;
 	u8 air_switch[SCARLETT2_AIR_SWITCH_MAX];
 	u8 dsp_switch[SCARLETT2_DSP_SWITCH_MAX];
 	s32 compressor_values[SCARLETT2_COMPRESSOR_CTLS_MAX];
···
 	.peq_flt_total_count = 4,
 	.mute_input_count = 1,
 	.gain_input_count = 1,
+	.sp_hp_mute_names = vocaster_one_sp_hp_mute_names,
 
 	.port_count = {
 		[SCARLETT2_PORT_TYPE_NONE]     = { 1,  0 },
···
 	.mute_input_count = 2,
 	.gain_input_count = 2,
 	.has_bluetooth = 1,
+	.sp_hp_mute_names = vocaster_two_sp_hp_mute_names,
 
 	.port_count = {
 		[SCARLETT2_PORT_TYPE_NONE]     = {  1,  0 },
···
 	.put  = scarlett2_dim_mute_ctl_put
 };
 
+/*** Vocaster Speaker/Headphone Mute Controls ***/
+
+static int scarlett2_sp_hp_mute_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;
+
+	ucontrol->value.integer.value[0] =
+		!!(private->sp_hp_mute & (1 << elem->control));
+
+	return 0;
+}
+
+static int scarlett2_sp_hp_mute_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 index = elem->control;
+	int val, err;
+
+	guard(mutex)(&private->data_mutex);
+
+	if (private->hwdep_in_use)
+		return -EBUSY;
+
+	val = private->sp_hp_mute;
+
+	if (ucontrol->value.integer.value[0])
+		val |= (1 << index);
+	else
+		val &= ~(1 << index);
+
+	if (val == private->sp_hp_mute)
+		return 0;
+
+	private->sp_hp_mute = val;
+
+	/* Send change to the device */
+	err = scarlett2_usb_set_config(mixer, SCARLETT2_CONFIG_SP_HP_MUTE,
+				       0, val);
+
+	return err < 0 ? err : 1;
+}
+
+static const struct snd_kcontrol_new scarlett2_sp_hp_mute_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "",
+	.info = snd_ctl_boolean_mono_info,
+	.get  = scarlett2_sp_hp_mute_ctl_get,
+	.put  = scarlett2_sp_hp_mute_ctl_put
+};
+
 /*** Create the analogue output controls ***/
 
 static int scarlett2_add_line_out_ctls(struct usb_mixer_interface *mixer)
···
 		if (err < 0)
 			return err;
 	}
+
+	/* Add Vocaster speaker/headphone mute controls */
+	if (private->info->sp_hp_mute_names)
+		for (i = 0; private->info->sp_hp_mute_names[i]; i++) {
+			err = scarlett2_add_new_ctl(
+				mixer, &scarlett2_sp_hp_mute_ctl,
+				i, 1, private->info->sp_hp_mute_names[i],
+				NULL);
+			if (err < 0)
+				return err;
+		}
 
 	/* Remaining controls are only applicable if the device
 	 * has per-channel line-out volume controls.