added (untested) support for 6i6

sound/usb/mixer.c

@@ -2389,6 +2389,7 @@ int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
 	}
 
 	switch (chip->usb_id) {
+	case USB_ID(0x1235, 0x8012): /* Focusrite Scarlett 6i6 */
 	case USB_ID(0x1235, 0x8002): /* Focusrite Scarlett 8i6 */
 	case USB_ID(0x1235, 0x8004): /* Focusrite Scarlett 18i6 */
 	case USB_ID(0x1235, 0x8014): /* Focusrite Scarlett 18i8 */

sound/usb/scarlettmixer.c

@@ -917,6 +917,28 @@ static int add_output_ctls(struct usb_mixer_interface *mixer,
 
 
 /********************** device-specific config *************************/
+static int scarlet_s6i6_controls(struct usb_mixer_interface *mixer,
+                                 const struct scarlett_device_info *info)
+{
+	struct scarlett_mixer_elem_info *elem;
+	int err;
+
+	CTLS_OUTPUT(0, "Monitor");
+	CTLS_OUTPUT(1, "Headphone 2");
+	CTLS_OUTPUT(2, "SPDIF");
+
+	CTL_ENUM  (0x01, 0x09, 1, "Input 1 Impedance Switch", &opt_impedance);
+	CTL_ENUM  (0x01, 0x0b, 1, "Input 1 Pad Switch", &opt_pad);
+
+	CTL_ENUM  (0x01, 0x09, 2, "Input 2 Impedance Switch", &opt_impedance);
+	CTL_ENUM  (0x01, 0x0b, 2, "Input 2 Pad Switch", &opt_pad);
+
+	CTL_ENUM  (0x01, 0x0b, 3, "Input 3 Pad Switch", &opt_pad);
+	CTL_ENUM  (0x01, 0x0b, 4, "Input 4 Pad Switch", &opt_pad);
+
+	return 0;
+}
+
 static int scarlet_s8i6_controls(struct usb_mixer_interface *mixer,
                                  const struct scarlett_device_info *info)
 {
@@ -1006,6 +1028,52 @@ static int scarlet_s18i20_controls(struct usb_mixer_interface *mixer,
 	return 0;
 }
 
+static const char *s6i6_texts[] = {
+	txtOff, /* 'off' == 0xff */
+	txtPcm1, txtPcm2, txtPcm3, txtPcm4,
+	txtPcm5, txtPcm6, txtPcm7, txtPcm8,
+	txtPcm9, txtPcm10, txtPcm11, txtPcm12,
+	txtAnlg1, txtAnlg2, txtAnlg3, txtAnlg4,
+	txtSpdif1, txtSpdif2,
+	txtMix1, txtMix2, txtMix3, txtMix4,
+	txtMix5, txtMix6, txtMix7, txtMix8
+};
+
+/*  untested...  */
+static const struct scarlett_device_info s6i6_info = {
+	.matrix_in = 18,
+	.matrix_out = 8,
+	.input_len = 6,
+	.output_len = 6,
+
+	.pcm_start = 0,
+	.analog_start = 12,
+	.spdif_start = 16,
+	.adat_start = 18,
+	.mix_start = 18,
+
+	.opt_master = {
+		.start = -1,
+		.len = 27,
+		.texts = s6i6_texts
+	},
+
+	.opt_matrix = {
+		.start = -1,
+		.len = 19,
+		.texts = s6i6_texts
+	},
+
+	.controls_fn = scarlet_s6i6_controls,
+	.matrix_mux_init = {
+		12, 13, 14, 15,                 // Analog -> 1..4
+		16, 17,                          // SPDIF -> 5,6
+		0, 1, 2, 3, 4, 5, 6, 7,     // PCM[1..12] -> 7..18
+		8, 9, 10, 11
+	}
+};
+
+// and 2 loop channels: Mix1, Mix2
 static const char *s8i6_texts[] = {
 	txtOff, /* 'off' == 0xff */
 	txtPcm1, txtPcm2, txtPcm3, txtPcm4,
@@ -1220,6 +1288,7 @@ int scarlett_mixer_controls(struct usb_mixer_interface *mixer)
 	CTL_MASTER(0x0a, 0x02, 0, 1, "Master Playback Volume");
 
 	switch (mixer->chip->usb_id) {
+	case USB_ID(0x1235, 0x8012): info = &s6i6_info; break;
 	case USB_ID(0x1235, 0x8002): info = &s8i6_info; break;
 	case USB_ID(0x1235, 0x8004): info = &s18i6_info; break;
 	case USB_ID(0x1235, 0x8014): info = &s18i8_info; break;