Merge tag 'sound-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

Pull sound updates from Takashi Iwai:
 "This became a fairly large pull request.  In addition to the usual
  driver updates / fixes, there have been a high amount of cleanups in
  ASoC area, as well as control API helpers and kernel documentations
  fixes touching through the whole tree.

  In the driver side, the biggest changes are the support for new Intel
  SoC found on new x86 machines, and the updates of FireWire dice and
  oxfw drivers.

  Some remarkable items are below:

  ALSA core:
   - PCM mmap code cleanup, removal of arch-dependent codes
   - PCM xrun injection support
   - PCM hwptr tracepoint support
   - Refactoring of snd_pcm_action(), simplification of PCM locking
   - Robustified sequecner auto-load functionality
   - New control API helpers and lots of cleanups along with them
   - Lots of kerneldoc fixes and cleanups

  USB-audio:
   - The mixer resume code was largely rewritten, and the devices with
     quirks are resumed properly.
   - New hardware support: Focusrite Scarlett, Digidesign Mbox1,
     Denon/Marantz DACs, Zoom R16/24

  FireWire:
   - DICE driver updates with better duplex and sync support, including
     MIDI support
   - New OXFW driver for Oxford Semiconductor FW970/971 chipset,
     including the previous LaCie Speakers device.  Fullduplex and MIDI
     support included as well as DICE driver.

  HD-audio:
   - Refactoring the driver-caps quirk handling in snd-hda-intel
   - More consistent control names representing the topology better
   - Fixups: HP mute LED with ALC268 codec, Ideapad S210 built-in mic
     fix, ASUS Z99He laptop EAPD

  ASoC:
   - Conversion of AC'97 drivers to use regmap, bringing us closer to
     the removal of the ASoC level I/O code
   - Clean up a lot of old drivers that were open coding things that
     have subsequently been implemented in the core
   - Some DAPM performance improvements
   - Removal of the now seldom used CODEC mutex
   - Lots of updates for the newer Intel SoC support, including support
     for the DSP and some Cherrytrail and Braswell machine drivers
   - Support for Samsung boards using rt5631 as the CODEC
   - Removal of the obsolete AFEB9260 machine driver
   - Driver support for the TI TS3A227E headset driver used in some
     Chrombeooks

  Others:
   - ASIHPI driver update and cleanups
   - Lots of dev_*() printk conversions
   - Lots of trivial cleanups for the codes spotted by Coccinelle"

* tag 'sound-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (594 commits)
  ALSA: pcxhr: NULL dereference on probe failure
  ALSA: lola: NULL dereference on probe failure
  ALSA: hda - Add "eapd" model string for AD1986A codec
  ALSA: hda - Add EAPD fixup for ASUS Z99He laptop
  ALSA: oxfw: Add hwdep interface
  ALSA: oxfw: Add support for capture/playback MIDI messages
  ALSA: oxfw: add support for capturing PCM samples
  ALSA: oxfw: Add support AMDTP in-stream
  ALSA: oxfw: Add support for Behringer/Mackie devices
  ALSA: oxfw: Change the way to start stream
  ALSA: oxfw: Add proc interface for debugging purpose
  ALSA: oxfw: Change the way to make PCM rules/constraints
  ALSA: oxfw: Add support for AV/C stream format command to get/set supported stream formation
  ALSA: oxfw: Change the way to name card
  ALSA: dice: Add support for MIDI capture/playback
  ALSA: dice: Add support for capturing PCM samples
  ALSA: dice: Support for non SYT-Match sampling clock source mode
  ALSA: dice: Add support for duplex streams with synchronization
  ALSA: dice: Change the way to start stream
  ALSA: jack: Add dummy snd_jack_set_key() definition
  ...

1 files changed, 1004 insertions, 0 deletions

diff --git a/sound/usb/mixer_scarlett.c b/sound/usb/mixer_scarlett.c
new file mode 100644
index 0000000..9109652
--- /dev/null
+++ b/sound/usb/mixer_scarlett.c
@@ -0,0 +1,1004 @@
+/*
+ *   Scarlett Driver for ALSA
+ *
+ *   Copyright (c) 2013 by Tobias Hoffmann
+ *   Copyright (c) 2013 by Robin Gareus <robin at gareus.org>
+ *   Copyright (c) 2002 by Takashi Iwai <tiwai at suse.de>
+ *   Copyright (c) 2014 by Chris J Arges <chris.j.arges at canonical.com>
+ *
+ *   Many codes borrowed from audio.c by
+ *	    Alan Cox (alan at lxorguk.ukuu.org.uk)
+ *	    Thomas Sailer (sailer at ife.ee.ethz.ch)
+ *
+ *   Code cleanup:
+ *   David Henningsson <david.henningsson at canonical.com>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ */
+
+/*
+ * Rewritten and extended to support more models, e.g. Scarlett 18i8.
+ *
+ * Auto-detection via UAC2 is not feasible to properly discover the vast
+ * majority of features. It's related to both Linux/ALSA's UAC2 as well as
+ * Focusrite's implementation of it. Eventually quirks may be sufficient but
+ * right now it's a major headache to work arount these things.
+ *
+ * NB. Neither the OSX nor the win driver provided by Focusrite performs
+ * discovery, they seem to operate the same as this driver.
+ */
+
+/* Mixer Interface for the Focusrite Scarlett 18i6 audio interface.
+ *
+ * The protocol was reverse engineered by looking at communication between
+ * Scarlett MixControl (v 1.2.128.0) and the Focusrite(R) Scarlett 18i6
+ * (firmware v305) using wireshark and usbmon in January 2013.
+ * Extended in July 2013.
+ *
+ * this mixer gives complete access to all features of the device:
+ *  - change Impedance of inputs (Line-in, Mic / Instrument, Hi-Z)
+ *  - select clock source
+ *  - dynamic input to mixer-matrix assignment
+ *  - 18 x 6 mixer-matrix gain stages
+ *  - bus routing & volume control
+ *  - automatic re-initialization on connect if device was power-cycled
+ *
+ * USB URB commands overview (bRequest = 0x01 = UAC2_CS_CUR)
+ * wIndex
+ * 0x01 Analog Input line/instrument impedance switch, wValue=0x0901 +
+ *      channel, data=Line/Inst (2bytes)
+ *      pad (-10dB) switch, wValue=0x0b01 + channel, data=Off/On (2bytes)
+ *      ?? wValue=0x0803/04, ?? (2bytes)
+ * 0x0a Master Volume, wValue=0x0200+bus[0:all + only 1..4?] data(2bytes)
+ *      Bus Mute/Unmute wValue=0x0100+bus[0:all + only 1..4?], data(2bytes)
+ * 0x28 Clock source, wValue=0x0100, data={1:int,2:spdif,3:adat} (1byte)
+ * 0x29 Set Sample-rate, wValue=0x0100, data=sample-rate(4bytes)
+ * 0x32 Mixer mux, wValue=0x0600 + mixer-channel, data=input-to-connect(2bytes)
+ * 0x33 Output mux, wValue=bus, data=input-to-connect(2bytes)
+ * 0x34 Capture mux, wValue=0...18, data=input-to-connect(2bytes)
+ * 0x3c Matrix Mixer gains, wValue=mixer-node  data=gain(2bytes)
+ *      ?? [sometimes](4bytes, e.g 0x000003be 0x000003bf ...03ff)
+ *
+ * USB reads: (i.e. actually issued by original software)
+ * 0x01 wValue=0x0901+channel (1byte!!), wValue=0x0b01+channed (1byte!!)
+ * 0x29 wValue=0x0100 sample-rate(4bytes)
+ *      wValue=0x0200 ?? 1byte (only once)
+ * 0x2a wValue=0x0100 ?? 4bytes, sample-rate2 ??
+ *
+ * USB reads with bRequest = 0x03 = UAC2_CS_MEM
+ * 0x3c wValue=0x0002 1byte: sync status (locked=1)
+ *      wValue=0x0000 18*2byte: peak meter (inputs)
+ *      wValue=0x0001 8(?)*2byte: peak meter (mix)
+ *      wValue=0x0003 6*2byte: peak meter (pcm/daw)
+ *
+ * USB write with bRequest = 0x03
+ * 0x3c Save settings to hardware: wValue=0x005a, data=0xa5
+ *
+ *
+ * <ditaa>
+ *  /--------------\    18chn            6chn    /--------------\
+ *  | Hardware  in +--+-------\        /------+--+ ALSA PCM out |
+ *  \--------------/  |       |        |      |  \--------------/
+ *                    |       |        |      |
+ *                    |       v        v      |
+ *                    |   +---------------+   |
+ *                    |    \ Matrix  Mux /    |
+ *                    |     +-----+-----+     |
+ *                    |           |           |
+ *                    |           | 18chn     |
+ *                    |           v           |
+ *                    |     +-----------+     |
+ *                    |     | Mixer     |     |
+ *                    |     |    Matrix |     |
+ *                    |     |           |     |
+ *                    |     | 18x6 Gain |     |
+ *                    |     |   stages  |     |
+ *                    |     +-----+-----+     |
+ *                    |           |           |
+ *                    |           |           |
+ *                    | 18chn     | 6chn      | 6chn
+ *                    v           v           v
+ *                    =========================
+ *             +---------------+     +--—------------+
+ *              \ Output  Mux /       \ Capture Mux /
+ *               +-----+-----+         +-----+-----+
+ *                     |                     |
+ *                     | 6chn                |
+ *                     v                     |
+ *              +-------------+              |
+ *              | Master Gain |              |
+ *              +------+------+              |
+ *                     |                     |
+ *                     | 6chn                | 18chn
+ *                     | (3 stereo pairs)    |
+ *  /--------------\   |                     |   /--------------\
+ *  | Hardware out |<--/                     \-->| ALSA PCM  in |
+ *  \--------------/                             \--------------/
+ * </ditaa>
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/usb/audio-v2.h>
+
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/tlv.h>
+
+#include "usbaudio.h"
+#include "mixer.h"
+#include "helper.h"
+#include "power.h"
+
+#include "mixer_scarlett.h"
+
+/* some gui mixers can't handle negative ctl values */
+#define SND_SCARLETT_LEVEL_BIAS 128
+#define SND_SCARLETT_MATRIX_IN_MAX 18
+#define SND_SCARLETT_CONTROLS_MAX 10
+#define SND_SCARLETT_OFFSETS_MAX 5
+
+enum {
+	SCARLETT_OUTPUTS,
+	SCARLETT_SWITCH_IMPEDANCE,
+	SCARLETT_SWITCH_PAD,
+};
+
+enum {
+	SCARLETT_OFFSET_PCM = 0,
+	SCARLETT_OFFSET_ANALOG = 1,
+	SCARLETT_OFFSET_SPDIF = 2,
+	SCARLETT_OFFSET_ADAT = 3,
+	SCARLETT_OFFSET_MIX = 4,
+};
+
+struct scarlett_mixer_elem_enum_info {
+	int start;
+	int len;
+	int offsets[SND_SCARLETT_OFFSETS_MAX];
+	char const * const *names;
+};
+
+struct scarlett_mixer_control {
+	unsigned char num;
+	unsigned char type;
+	const char *name;
+};
+
+struct scarlett_device_info {
+	int matrix_in;
+	int matrix_out;
+	int input_len;
+	int output_len;
+
+	struct scarlett_mixer_elem_enum_info opt_master;
+	struct scarlett_mixer_elem_enum_info opt_matrix;
+
+	/* initial values for matrix mux */
+	int matrix_mux_init[SND_SCARLETT_MATRIX_IN_MAX];
+
+	int num_controls;	/* number of items in controls */
+	const struct scarlett_mixer_control controls[SND_SCARLETT_CONTROLS_MAX];
+};
+
+/********************** Enum Strings *************************/
+
+static const struct scarlett_mixer_elem_enum_info opt_pad = {
+	.start = 0,
+	.len = 2,
+	.offsets = {},
+	.names = (char const * const []){
+		"0dB", "-10dB"
+	}
+};
+
+static const struct scarlett_mixer_elem_enum_info opt_impedance = {
+	.start = 0,
+	.len = 2,
+	.offsets = {},
+	.names = (char const * const []){
+		"Line", "Hi-Z"
+	}
+};
+
+static const struct scarlett_mixer_elem_enum_info opt_clock = {
+	.start = 1,
+	.len = 3,
+	.offsets = {},
+	.names = (char const * const []){
+		"Internal", "SPDIF", "ADAT"
+	}
+};
+
+static const struct scarlett_mixer_elem_enum_info opt_sync = {
+	.start = 0,
+	.len = 2,
+	.offsets = {},
+	.names = (char const * const []){
+		"No Lock", "Locked"
+	}
+};
+
+static int scarlett_ctl_switch_info(struct snd_kcontrol *kctl,
+		struct snd_ctl_elem_info *uinfo)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+	uinfo->count = elem->channels;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 1;
+	return 0;
+}
+
+static int scarlett_ctl_switch_get(struct snd_kcontrol *kctl,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	int i, err, val;
+
+	for (i = 0; i < elem->channels; i++) {
+		err = snd_usb_get_cur_mix_value(elem, i, i, &val);
+		if (err < 0)
+			return err;
+
+		val = !val; /* invert mute logic for mixer */
+		ucontrol->value.integer.value[i] = val;
+	}
+
+	return 0;
+}
+
+static int scarlett_ctl_switch_put(struct snd_kcontrol *kctl,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	int i, changed = 0;
+	int err, oval, val;
+
+	for (i = 0; i < elem->channels; i++) {
+		err = snd_usb_get_cur_mix_value(elem, i, i, &oval);
+		if (err < 0)
+			return err;
+
+		val = ucontrol->value.integer.value[i];
+		val = !val;
+		if (oval != val) {
+			err = snd_usb_set_cur_mix_value(elem, i, i, val);
+			if (err < 0)
+				return err;
+
+			changed = 1;
+		}
+	}
+
+	return changed;
+}
+
+static int scarlett_ctl_resume(struct usb_mixer_elem_list *list)
+{
+	struct usb_mixer_elem_info *elem =
+		container_of(list, struct usb_mixer_elem_info, head);
+	int i;
+
+	for (i = 0; i < elem->channels; i++)
+		if (elem->cached & (1 << i))
+			snd_usb_set_cur_mix_value(elem, i, i,
+						  elem->cache_val[i]);
+	return 0;
+}
+
+static int scarlett_ctl_info(struct snd_kcontrol *kctl,
+			     struct snd_ctl_elem_info *uinfo)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = elem->channels;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = (int)kctl->private_value +
+		SND_SCARLETT_LEVEL_BIAS;
+	uinfo->value.integer.step = 1;
+	return 0;
+}
+
+static int scarlett_ctl_get(struct snd_kcontrol *kctl,
+			    struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	int i, err, val;
+
+	for (i = 0; i < elem->channels; i++) {
+		err = snd_usb_get_cur_mix_value(elem, i, i, &val);
+		if (err < 0)
+			return err;
+
+		val = clamp(val / 256, -128, (int)kctl->private_value) +
+				    SND_SCARLETT_LEVEL_BIAS;
+		ucontrol->value.integer.value[i] = val;
+	}
+
+	return 0;
+}
+
+static int scarlett_ctl_put(struct snd_kcontrol *kctl,
+			    struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	int i, changed = 0;
+	int err, oval, val;
+
+	for (i = 0; i < elem->channels; i++) {
+		err = snd_usb_get_cur_mix_value(elem, i, i, &oval);
+		if (err < 0)
+			return err;
+
+		val = ucontrol->value.integer.value[i] -
+			SND_SCARLETT_LEVEL_BIAS;
+		val = val * 256;
+		if (oval != val) {
+			err = snd_usb_set_cur_mix_value(elem, i, i, val);
+			if (err < 0)
+				return err;
+
+			changed = 1;
+		}
+	}
+
+	return changed;
+}
+
+static void scarlett_generate_name(int i, char *dst, int offsets[])
+{
+	if (i > offsets[SCARLETT_OFFSET_MIX])
+		sprintf(dst, "Mix %c",
+			'A'+(i - offsets[SCARLETT_OFFSET_MIX] - 1));
+	else if (i > offsets[SCARLETT_OFFSET_ADAT])
+		sprintf(dst, "ADAT %d", i - offsets[SCARLETT_OFFSET_ADAT]);
+	else if (i > offsets[SCARLETT_OFFSET_SPDIF])
+		sprintf(dst, "SPDIF %d", i - offsets[SCARLETT_OFFSET_SPDIF]);
+	else if (i > offsets[SCARLETT_OFFSET_ANALOG])
+		sprintf(dst, "Analog %d", i - offsets[SCARLETT_OFFSET_ANALOG]);
+	else if (i > offsets[SCARLETT_OFFSET_PCM])
+		sprintf(dst, "PCM %d", i - offsets[SCARLETT_OFFSET_PCM]);
+	else
+		sprintf(dst, "Off");
+}
+
+static int scarlett_ctl_enum_dynamic_info(struct snd_kcontrol *kctl,
+					  struct snd_ctl_elem_info *uinfo)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
+	unsigned int items = opt->len;
+
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
+	uinfo->count = elem->channels;
+	uinfo->value.enumerated.items = items;
+
+	if (uinfo->value.enumerated.item >= items)
+		uinfo->value.enumerated.item = items - 1;
+
+	/* generate name dynamically based on item number and offset info */
+	scarlett_generate_name(uinfo->value.enumerated.item,
+			       uinfo->value.enumerated.name,
+			       opt->offsets);
+
+	return 0;
+}
+
+static int scarlett_ctl_enum_info(struct snd_kcontrol *kctl,
+				  struct snd_ctl_elem_info *uinfo)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
+
+	return snd_ctl_enum_info(uinfo, elem->channels, opt->len,
+				 (const char * const *)opt->names);
+}
+
+static int scarlett_ctl_enum_get(struct snd_kcontrol *kctl,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
+	int err, val;
+
+	err = snd_usb_get_cur_mix_value(elem, 0, 0, &val);
+	if (err < 0)
+		return err;
+
+	val = clamp(val - opt->start, 0, opt->len-1);
+
+	ucontrol->value.enumerated.item[0] = val;
+
+	return 0;
+}
+
+static int scarlett_ctl_enum_put(struct snd_kcontrol *kctl,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct scarlett_mixer_elem_enum_info *opt = elem->private_data;
+	int err, oval, val;
+
+	err = snd_usb_get_cur_mix_value(elem, 0, 0, &oval);
+	if (err < 0)
+		return err;
+
+	val = ucontrol->value.integer.value[0];
+	val = val + opt->start;
+	if (val != oval) {
+		snd_usb_set_cur_mix_value(elem, 0, 0, val);
+		return 1;
+	}
+	return 0;
+}
+
+static int scarlett_ctl_enum_resume(struct usb_mixer_elem_list *list)
+{
+	struct usb_mixer_elem_info *elem =
+		container_of(list, struct usb_mixer_elem_info, head);
+
+	if (elem->cached)
+		snd_usb_set_cur_mix_value(elem, 0, 0, *elem->cache_val);
+	return 0;
+}
+
+static int scarlett_ctl_meter_get(struct snd_kcontrol *kctl,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_info *elem = kctl->private_data;
+	struct snd_usb_audio *chip = elem->head.mixer->chip;
+	unsigned char buf[2 * MAX_CHANNELS] = {0, };
+	int wValue = (elem->control << 8) | elem->idx_off;
+	int idx = snd_usb_ctrl_intf(chip) | (elem->head.id << 8);
+	int err;
+
+	err = snd_usb_ctl_msg(chip->dev,
+				usb_rcvctrlpipe(chip->dev, 0),
+				UAC2_CS_MEM,
+				USB_RECIP_INTERFACE | USB_TYPE_CLASS |
+				USB_DIR_IN, wValue, idx, buf, elem->channels);
+	if (err < 0)
+		return err;
+
+	ucontrol->value.enumerated.item[0] = clamp((int)buf[0], 0, 1);
+	return 0;
+}
+
+static struct snd_kcontrol_new usb_scarlett_ctl_switch = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "",
+	.info = scarlett_ctl_switch_info,
+	.get =  scarlett_ctl_switch_get,
+	.put =  scarlett_ctl_switch_put,
+};
+
+static const DECLARE_TLV_DB_SCALE(db_scale_scarlett_gain, -12800, 100, 0);
+
+static struct snd_kcontrol_new usb_scarlett_ctl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+		  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+	.name = "",
+	.info = scarlett_ctl_info,
+	.get =  scarlett_ctl_get,
+	.put =  scarlett_ctl_put,
+	.private_value = 6,  /* max value */
+	.tlv = { .p = db_scale_scarlett_gain }
+};
+
+static struct snd_kcontrol_new usb_scarlett_ctl_master = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+		  SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+	.name = "",
+	.info = scarlett_ctl_info,
+	.get =  scarlett_ctl_get,
+	.put =  scarlett_ctl_put,
+	.private_value = 6,  /* max value */
+	.tlv = { .p = db_scale_scarlett_gain }
+};
+
+static struct snd_kcontrol_new usb_scarlett_ctl_enum = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "",
+	.info = scarlett_ctl_enum_info,
+	.get =  scarlett_ctl_enum_get,
+	.put =  scarlett_ctl_enum_put,
+};
+
+static struct snd_kcontrol_new usb_scarlett_ctl_dynamic_enum = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "",
+	.info = scarlett_ctl_enum_dynamic_info,
+	.get =  scarlett_ctl_enum_get,
+	.put =  scarlett_ctl_enum_put,
+};
+
+static struct snd_kcontrol_new usb_scarlett_ctl_sync = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.access = SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
+	.name = "",
+	.info = scarlett_ctl_enum_info,
+	.get =  scarlett_ctl_meter_get,
+};
+
+static int add_new_ctl(struct usb_mixer_interface *mixer,
+		       const struct snd_kcontrol_new *ncontrol,
+		       usb_mixer_elem_resume_func_t resume,
+		       int index, int offset, int num,
+		       int val_type, int channels, const char *name,
+		       const struct scarlett_mixer_elem_enum_info *opt,
+		       struct usb_mixer_elem_info **elem_ret
+)
+{
+	struct snd_kcontrol *kctl;
+	struct usb_mixer_elem_info *elem;
+	int err;
+
+	elem = kzalloc(sizeof(*elem), GFP_KERNEL);
+	if (!elem)
+		return -ENOMEM;
+
+	elem->head.mixer = mixer;
+	elem->head.resume = resume;
+	elem->control = offset;
+	elem->idx_off = num;
+	elem->head.id = index;
+	elem->val_type = val_type;
+
+	elem->channels = channels;
+
+	/* add scarlett_mixer_elem_enum_info struct */
+	elem->private_data = (void *)opt;
+
+	kctl = snd_ctl_new1(ncontrol, elem);
+	if (!kctl) {
+		kfree(elem);
+		return -ENOMEM;
+	}
+	kctl->private_free = snd_usb_mixer_elem_free;
+
+	strlcpy(kctl->id.name, name, sizeof(kctl->id.name));
+
+	err = snd_usb_mixer_add_control(&elem->head, kctl);
+	if (err < 0)
+		return err;
+
+	if (elem_ret)
+		*elem_ret = elem;
+
+	return 0;
+}
+
+static int add_output_ctls(struct usb_mixer_interface *mixer,
+			   int index, const char *name,
+			   const struct scarlett_device_info *info)
+{
+	int err;
+	char mx[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+	struct usb_mixer_elem_info *elem;
+
+	/* Add mute switch */
+	snprintf(mx, sizeof(mx), "Master %d (%s) Playback Switch",
+		index + 1, name);
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_switch,
+			  scarlett_ctl_resume, 0x0a, 0x01,
+			  2*index+1, USB_MIXER_S16, 2, mx, NULL, &elem);
+	if (err < 0)
+		return err;
+
+	/* Add volume control and initialize to 0 */
+	snprintf(mx, sizeof(mx), "Master %d (%s) Playback Volume",
+		index + 1, name);
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_master,
+			  scarlett_ctl_resume, 0x0a, 0x02,
+			  2*index+1, USB_MIXER_S16, 2, mx, NULL, &elem);
+	if (err < 0)
+		return err;
+
+	/* Add L channel source playback enumeration */
+	snprintf(mx, sizeof(mx), "Master %dL (%s) Source Playback Enum",
+		index + 1, name);
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
+			  scarlett_ctl_enum_resume, 0x33, 0x00,
+			  2*index, USB_MIXER_S16, 1, mx, &info->opt_master,
+			  &elem);
+	if (err < 0)
+		return err;
+
+	/* Add R channel source playback enumeration */
+	snprintf(mx, sizeof(mx), "Master %dR (%s) Source Playback Enum",
+		index + 1, name);
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
+			  scarlett_ctl_enum_resume, 0x33, 0x00,
+			  2*index+1, USB_MIXER_S16, 1, mx, &info->opt_master,
+			  &elem);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+/********************** device-specific config *************************/
+
+/*  untested...  */
+static struct scarlett_device_info s6i6_info = {
+	.matrix_in = 18,
+	.matrix_out = 8,
+	.input_len = 6,
+	.output_len = 6,
+
+	.opt_master = {
+		.start = -1,
+		.len = 27,
+		.offsets = {0, 12, 16, 18, 18},
+		.names = NULL
+	},
+
+	.opt_matrix = {
+		.start = -1,
+		.len = 19,
+		.offsets = {0, 12, 16, 18, 18},
+		.names = NULL
+	},
+
+	.num_controls = 0,
+	.controls = {
+		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
+		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone" },
+		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
+		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 1, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+	},
+
+	.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
+	}
+};
+
+/*  untested...  */
+static struct scarlett_device_info s8i6_info = {
+	.matrix_in = 18,
+	.matrix_out = 6,
+	.input_len = 8,
+	.output_len = 6,
+
+	.opt_master = {
+		.start = -1,
+		.len = 25,
+		.offsets = {0, 12, 16, 18, 18},
+		.names = NULL
+	},
+
+	.opt_matrix = {
+		.start = -1,
+		.len = 19,
+		.offsets = {0, 12, 16, 18, 18},
+		.names = NULL
+	},
+
+	.num_controls = 7,
+	.controls = {
+		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
+		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone" },
+		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
+		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+	},
+
+	.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
+	}
+};
+
+static struct scarlett_device_info s18i6_info = {
+	.matrix_in = 18,
+	.matrix_out = 6,
+	.input_len = 18,
+	.output_len = 6,
+
+	.opt_master = {
+		.start = -1,
+		.len = 31,
+		.offsets = {0, 6, 14, 16, 24},
+		.names = NULL,
+	},
+
+	.opt_matrix = {
+		.start = -1,
+		.len = 25,
+		.offsets = {0, 6, 14, 16, 24},
+		.names = NULL,
+	},
+
+	.num_controls = 5,
+	.controls = {
+		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
+		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone" },
+		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
+		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+	},
+
+	.matrix_mux_init = {
+		 6,  7,  8,  9, 10, 11, 12, 13, /* Analog -> 1..8 */
+		16, 17, 18, 19, 20, 21,     /* ADAT[1..6] -> 9..14 */
+		14, 15,                          /* SPDIF -> 15,16 */
+		0, 1                          /* PCM[1,2] -> 17,18 */
+	}
+};
+
+static struct scarlett_device_info s18i8_info = {
+	.matrix_in = 18,
+	.matrix_out = 8,
+	.input_len = 18,
+	.output_len = 8,
+
+	.opt_master = {
+		.start = -1,
+		.len = 35,
+		.offsets = {0, 8, 16, 18, 26},
+		.names = NULL
+	},
+
+	.opt_matrix = {
+		.start = -1,
+		.len = 27,
+		.offsets = {0, 8, 16, 18, 26},
+		.names = NULL
+	},
+
+	.num_controls = 10,
+	.controls = {
+		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
+		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Headphone 1" },
+		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "Headphone 2" },
+		{ .num = 3, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
+		{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 1, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+	},
+
+	.matrix_mux_init = {
+		 8,  9, 10, 11, 12, 13, 14, 15, /* Analog -> 1..8 */
+		18, 19, 20, 21, 22, 23,     /* ADAT[1..6] -> 9..14 */
+		16, 17,                          /* SPDIF -> 15,16 */
+		0, 1                          /* PCM[1,2] -> 17,18 */
+	}
+};
+
+static struct scarlett_device_info s18i20_info = {
+	.matrix_in = 18,
+	.matrix_out = 8,
+	.input_len = 18,
+	.output_len = 20,
+
+	.opt_master = {
+		.start = -1,
+		.len = 47,
+		.offsets = {0, 20, 28, 30, 38},
+		.names = NULL
+	},
+
+	.opt_matrix = {
+		.start = -1,
+		.len = 39,
+		.offsets = {0, 20, 28, 30, 38},
+		.names = NULL
+	},
+
+	.num_controls = 10,
+	.controls = {
+		{ .num = 0, .type = SCARLETT_OUTPUTS, .name = "Monitor" },
+		{ .num = 1, .type = SCARLETT_OUTPUTS, .name = "Line 3/4" },
+		{ .num = 2, .type = SCARLETT_OUTPUTS, .name = "Line 5/6" },
+		{ .num = 3, .type = SCARLETT_OUTPUTS, .name = "Line 7/8" },
+		{ .num = 4, .type = SCARLETT_OUTPUTS, .name = "Line 9/10" },
+		{ .num = 5, .type = SCARLETT_OUTPUTS, .name = "SPDIF" },
+		{ .num = 6, .type = SCARLETT_OUTPUTS, .name = "ADAT 1/2" },
+		{ .num = 7, .type = SCARLETT_OUTPUTS, .name = "ADAT 3/4" },
+		{ .num = 8, .type = SCARLETT_OUTPUTS, .name = "ADAT 5/6" },
+		{ .num = 9, .type = SCARLETT_OUTPUTS, .name = "ADAT 7/8" },
+		/*{ .num = 1, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 1, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_IMPEDANCE, .name = NULL},
+		{ .num = 2, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 3, .type = SCARLETT_SWITCH_PAD, .name = NULL},
+		{ .num = 4, .type = SCARLETT_SWITCH_PAD, .name = NULL},*/
+	},
+
+	.matrix_mux_init = {
+		20, 21, 22, 23, 24, 25, 26, 27, /* Analog -> 1..8 */
+		30, 31, 32, 33, 34, 35,     /* ADAT[1..6] -> 9..14 */
+		28, 29,                          /* SPDIF -> 15,16 */
+		0, 1                          /* PCM[1,2] -> 17,18 */
+	}
+};
+
+
+static int scarlett_controls_create_generic(struct usb_mixer_interface *mixer,
+	struct scarlett_device_info *info)
+{
+	int i, err;
+	char mx[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+	const struct scarlett_mixer_control *ctl;
+	struct usb_mixer_elem_info *elem;
+
+	/* create master switch and playback volume */
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_switch,
+			  scarlett_ctl_resume, 0x0a, 0x01, 0,
+			  USB_MIXER_S16, 1, "Master Playback Switch", NULL,
+			  &elem);
+	if (err < 0)
+		return err;
+
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_master,
+			  scarlett_ctl_resume, 0x0a, 0x02, 0,
+			  USB_MIXER_S16, 1, "Master Playback Volume", NULL,
+			  &elem);
+	if (err < 0)
+		return err;
+
+	/* iterate through controls in info struct and create each one */
+	for (i = 0; i < info->num_controls; i++) {
+		ctl = &info->controls[i];
+
+		switch (ctl->type) {
+		case SCARLETT_OUTPUTS:
+			err = add_output_ctls(mixer, ctl->num, ctl->name, info);
+			if (err < 0)
+				return err;
+			break;
+		case SCARLETT_SWITCH_IMPEDANCE:
+			sprintf(mx, "Input %d Impedance Switch", ctl->num);
+			err = add_new_ctl(mixer, &usb_scarlett_ctl_enum,
+					  scarlett_ctl_enum_resume, 0x01,
+					  0x09, ctl->num, USB_MIXER_S16, 1, mx,
+					  &opt_impedance, &elem);
+			if (err < 0)
+				return err;
+			break;
+		case SCARLETT_SWITCH_PAD:
+			sprintf(mx, "Input %d Pad Switch", ctl->num);
+			err = add_new_ctl(mixer, &usb_scarlett_ctl_enum,
+					  scarlett_ctl_enum_resume, 0x01,
+					  0x0b, ctl->num, USB_MIXER_S16, 1, mx,
+					  &opt_pad, &elem);
+			if (err < 0)
+				return err;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Create and initialize a mixer for the Focusrite(R) Scarlett
+ */
+int snd_scarlett_controls_create(struct usb_mixer_interface *mixer)
+{
+	int err, i, o;
+	char mx[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+	struct scarlett_device_info *info;
+	struct usb_mixer_elem_info *elem;
+	static char sample_rate_buffer[4] = { '\x80', '\xbb', '\x00', '\x00' };
+
+	/* only use UAC_VERSION_2 */
+	if (!mixer->protocol)
+		return 0;
+
+	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;
+	case USB_ID(0x1235, 0x800c):
+		info = &s18i20_info;
+		break;
+	default: /* device not (yet) supported */
+		return -EINVAL;
+	}
+
+	/* generic function to create controls */
+	err = scarlett_controls_create_generic(mixer, info);
+	if (err < 0)
+		return err;
+
+	/* setup matrix controls */
+	for (i = 0; i < info->matrix_in; i++) {
+		snprintf(mx, sizeof(mx), "Matrix %02d Input Playback Route",
+			 i+1);
+		err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
+				  scarlett_ctl_enum_resume, 0x32,
+				  0x06, i, USB_MIXER_S16, 1, mx,
+				  &info->opt_matrix, &elem);
+		if (err < 0)
+			return err;
+
+		for (o = 0; o < info->matrix_out; o++) {
+			sprintf(mx, "Matrix %02d Mix %c Playback Volume", i+1,
+				o+'A');
+			err = add_new_ctl(mixer, &usb_scarlett_ctl,
+					  scarlett_ctl_resume, 0x3c, 0x00,
+					  (i << 3) + (o & 0x07), USB_MIXER_S16,
+					  1, mx, NULL, &elem);
+			if (err < 0)
+				return err;
+
+		}
+	}
+
+	for (i = 0; i < info->input_len; i++) {
+		snprintf(mx, sizeof(mx), "Input Source %02d Capture Route",
+			 i+1);
+		err = add_new_ctl(mixer, &usb_scarlett_ctl_dynamic_enum,
+				  scarlett_ctl_enum_resume, 0x34,
+				  0x00, i, USB_MIXER_S16, 1, mx,
+				  &info->opt_master, &elem);
+		if (err < 0)
+			return err;
+	}
+
+	/* val_len == 1 needed here */
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_enum,
+			  scarlett_ctl_enum_resume, 0x28, 0x01, 0,
+			  USB_MIXER_U8, 1, "Sample Clock Source",
+			  &opt_clock, &elem);
+	if (err < 0)
+		return err;
+
+	/* val_len == 1 and UAC2_CS_MEM */
+	err = add_new_ctl(mixer, &usb_scarlett_ctl_sync, NULL, 0x3c, 0x00, 2,
+			  USB_MIXER_U8, 1, "Sample Clock Sync Status",
+			  &opt_sync, &elem);
+	if (err < 0)
+		return err;
+
+	/* initialize sampling rate to 48000 */
+	err = snd_usb_ctl_msg(mixer->chip->dev,
+		usb_sndctrlpipe(mixer->chip->dev, 0), UAC2_CS_CUR,
+		USB_RECIP_INTERFACE | USB_TYPE_CLASS |
+		USB_DIR_OUT, 0x0100, snd_usb_ctrl_intf(mixer->chip) |
+		(0x29 << 8), sample_rate_buffer, 4);
+	if (err < 0)
+		return err;
+
+	return err;
+}