mixer_scarlett_gen2.c

// SPDX-License-Identifier: GPL-2.0
/*
 *   Focusrite Scarlett Gen 2/3 Driver for ALSA
 *
 *   Supported models:
 *   - 6i6/18i8/18i20 Gen 2
 *   - Solo/2i2/4i4/8i6/18i8/18i20 Gen 3
 *
 *   Copyright (c) 2018-2021 by Geoffrey D. Bennett <g at b4.vu>
 *   Copyright (c) 2020-2021 by Vladimir Sadovnikov <sadko4u@gmail.com>
 *
 *   Based on the Scarlett (Gen 1) 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>
 */

/* The protocol was reverse engineered by looking at the communication
 * between Focusrite Control 2.3.4 and the Focusrite(R) Scarlett 18i20
 * (firmware 1083) using usbmon in July-August 2018.
 *
 * Scarlett 18i8 support added in April 2019.
 *
 * Scarlett 6i6 support added in June 2019 (thanks to Martin Wittmann
 * for providing usbmon output and testing).
 *
 * Scarlett 4i4/8i6 Gen 3 support added in May 2020 (thanks to Laurent
 * Debricon for donating a 4i4 and to Fredrik Unger for providing 8i6
 * usbmon output and testing).
 *
 * Scarlett 18i8/18i20 Gen 3 support added in June 2020 (thanks to
 * Darren Jaeckel, Alex Sedlack, and Clovis Lunel for providing usbmon
 * output, protocol traces and testing).
 *
 * Support for loading mixer volume and mux configuration from the
 * interface during driver initialisation added in May 2021 (thanks to
 * Vladimir Sadovnikov for figuring out how).
 *
 * Support for Solo/2i2 Gen 3 added in May 2021 (thanks to Alexander
 * Vorona for 2i2 protocol traces).
 *
 * 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
 *  - mixer-matrix gain stages
 *  - gain/volume/mute controls
 *  - level meters
 *  - line/inst level, pad, and air controls
 *  - phantom power, direct monitor, speaker switching, and talkback
 *    controls
 *  - disable/enable MSD mode
 *
 * <ditaa>
 *    /--------------\    18chn            20chn     /--------------\
 *    | Hardware  in +--+------\    /-------------+--+ ALSA PCM out |
 *    \--------------/  |      |    |             |  \--------------/
 *                      |      |    |    /-----\  |
 *                      |      |    |    |     |  |
 *                      |      v    v    v     |  |
 *                      |   +---------------+  |  |
 *                      |    \ Matrix  Mux /   |  |
 *                      |     +-----+-----+    |  |
 *                      |           |          |  |
 *                      |           |18chn     |  |
 *                      |           |          |  |
 *                      |           |     10chn|  |
 *                      |           v          |  |
 *                      |     +------------+   |  |
 *                      |     | Mixer      |   |  |
 *                      |     |     Matrix |   |  |
 *                      |     |            |   |  |
 *                      |     | 18x10 Gain |   |  |
 *                      |     |   stages   |   |  |
 *                      |     +-----+------+   |  |
 *                      |           |          |  |
 *                      |18chn      |10chn     |  |20chn
 *                      |           |          |  |
 *                      |           +----------/  |
 *                      |           |             |
 *                      v           v             v
 *                      ===========================
 *               +---------------+       +--—------------+
 *                \ Output  Mux /         \ Capture Mux /
 *                 +---+---+---+           +-----+-----+
 *                     |   |                     |
 *                10chn|   |                     |18chn
 *                     |   |                     |
 *  /--------------\   |   |                     |   /--------------\
 *  | S/PDIF, ADAT |<--/   |10chn                \-->| ALSA PCM in  |
 *  | Hardware out |       |                         \--------------/
 *  \--------------/       |
 *                         v
 *                  +-------------+    Software gain per channel.
 *                  | Master Gain |<-- 18i20 only: Switch per channel
 *                  +------+------+    to select HW or SW gain control.
 *                         |
 *                         |10chn
 *  /--------------\       |
 *  | Analogue     |<------/
 *  | Hardware out |
 *  \--------------/
 * </ditaa>
 *
 * Gen 3 devices have a Mass Storage Device (MSD) mode where a small
 * disk with registration and driver download information is presented
 * to the host. To access the full functionality of the device without
 * proprietary software, MSD mode can be disabled by:
 * - holding down the 48V button for five seconds while powering on
 *   the device, or
 * - using this driver and alsamixer to change the "MSD Mode" setting
 *   to Off and power-cycling the device
 */

#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/moduleparam.h>

#include <sound/control.h>
#include <sound/tlv.h>

#include "usbaudio.h"
#include "mixer.h"
#include "helper.h"

#include "mixer_scarlett_gen2.h"

/* device_setup value to enable */
#define SCARLETT2_ENABLE 0x01

/* device_setup value to allow turning MSD mode back on */
#define SCARLETT2_MSD_ENABLE 0x02

/* some gui mixers can't handle negative ctl values */
#define SCARLETT2_VOLUME_BIAS 127

/* mixer range from -80dB to +6dB in 0.5dB steps */
#define SCARLETT2_MIXER_MIN_DB -80
#define SCARLETT2_MIXER_BIAS (-SCARLETT2_MIXER_MIN_DB * 2)
#define SCARLETT2_MIXER_MAX_DB 6
#define SCARLETT2_MIXER_MAX_VALUE \
	((SCARLETT2_MIXER_MAX_DB - SCARLETT2_MIXER_MIN_DB) * 2)
#define SCARLETT2_MIXER_VALUE_COUNT (SCARLETT2_MIXER_MAX_VALUE + 1)

/* map from (dB + 80) * 2 to mixer value
 * for dB in 0 .. 172: int(8192 * pow(10, ((dB - 160) / 2 / 20)))
 */
static const u16 scarlett2_mixer_values[SCARLETT2_MIXER_VALUE_COUNT] = {
	0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2,
	2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 8, 8,
	9, 9, 10, 10, 11, 12, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
	23, 24, 25, 27, 29, 30, 32, 34, 36, 38, 41, 43, 46, 48, 51,
	54, 57, 61, 65, 68, 73, 77, 81, 86, 91, 97, 103, 109, 115,
	122, 129, 137, 145, 154, 163, 173, 183, 194, 205, 217, 230,
	244, 259, 274, 290, 307, 326, 345, 365, 387, 410, 434, 460,
	487, 516, 547, 579, 614, 650, 689, 730, 773, 819, 867, 919,
	973, 1031, 1092, 1157, 1225, 1298, 1375, 1456, 1543, 1634,
	1731, 1833, 1942, 2057, 2179, 2308, 2445, 2590, 2744, 2906,
	3078, 3261, 3454, 3659, 3876, 4105, 4349, 4606, 4879, 5168,
	5475, 5799, 6143, 6507, 6892, 7301, 7733, 8192, 8677, 9191,
	9736, 10313, 10924, 11571, 12257, 12983, 13752, 14567, 15430,
	16345
};

/* Maximum number of analogue outputs */
#define SCARLETT2_ANALOGUE_MAX 10

/* Maximum number of level and pad switches */
#define SCARLETT2_LEVEL_SWITCH_MAX 2
#define SCARLETT2_PAD_SWITCH_MAX 8
#define SCARLETT2_AIR_SWITCH_MAX 8
#define SCARLETT2_PHANTOM_SWITCH_MAX 2

/* Maximum number of inputs to the mixer */
#define SCARLETT2_INPUT_MIX_MAX 25

/* Maximum number of outputs from the mixer */
#define SCARLETT2_OUTPUT_MIX_MAX 12

/* Maximum size of the data in the USB mux assignment message:
 * 20 inputs, 20 outputs, 25 matrix inputs, 12 spare
 */
#define SCARLETT2_MUX_MAX 77

/* Maximum number of meters (sum of output port counts) */
#define SCARLETT2_MAX_METERS 65

/* Hardware port types:
 * - None (no input to mux)
 * - Analogue I/O
 * - S/PDIF I/O
 * - ADAT I/O
 * - Mixer I/O
 * - PCM I/O
 */
enum {
	SCARLETT2_PORT_TYPE_NONE     = 0,
	SCARLETT2_PORT_TYPE_ANALOGUE = 1,
	SCARLETT2_PORT_TYPE_SPDIF    = 2,
	SCARLETT2_PORT_TYPE_ADAT     = 3,
	SCARLETT2_PORT_TYPE_MIX      = 4,
	SCARLETT2_PORT_TYPE_PCM      = 5,
	SCARLETT2_PORT_TYPE_COUNT    = 6,
};

/* I/O count of each port type kept in struct scarlett2_ports */
enum {
	SCARLETT2_PORT_IN    = 0,
	SCARLETT2_PORT_OUT   = 1,
	SCARLETT2_PORT_DIRNS = 2,
};

/* Dim/Mute buttons on the 18i20 */
enum {
	SCARLETT2_BUTTON_MUTE    = 0,
	SCARLETT2_BUTTON_DIM     = 1,
	SCARLETT2_DIM_MUTE_COUNT = 2,
};

static const char *const scarlett2_dim_mute_names[SCARLETT2_DIM_MUTE_COUNT] = {
	"Mute", "Dim"
};

/* Description of each hardware port type:
 * - id: hardware ID of this port type
 * - src_descr: printf format string for mux input selections
 * - src_num_offset: added to channel number for the fprintf
 * - dst_descr: printf format string for mixer controls
 */
struct scarlett2_port {
	u16 id;
	const char * const src_descr;
	int src_num_offset;
	const char * const dst_descr;
};

static const struct scarlett2_port scarlett2_ports[SCARLETT2_PORT_TYPE_COUNT] = {
	[SCARLETT2_PORT_TYPE_NONE] = {
		.id = 0x000,
		.src_descr = "Off"
	},
	[SCARLETT2_PORT_TYPE_ANALOGUE] = {
		.id = 0x080,
		.src_descr = "Analogue %d",
		.src_num_offset = 1,
		.dst_descr = "Analogue Output %02d Playback"
	},
	[SCARLETT2_PORT_TYPE_SPDIF] = {
		.id = 0x180,
		.src_descr = "S/PDIF %d",
		.src_num_offset = 1,
		.dst_descr = "S/PDIF Output %d Playback"
	},
	[SCARLETT2_PORT_TYPE_ADAT] = {
		.id = 0x200,
		.src_descr = "ADAT %d",
		.src_num_offset = 1,
		.dst_descr = "ADAT Output %d Playback"
	},
	[SCARLETT2_PORT_TYPE_MIX] = {
		.id = 0x300,
		.src_descr = "Mix %c",
		.src_num_offset = 'A',
		.dst_descr = "Mixer Input %02d Capture"
	},
	[SCARLETT2_PORT_TYPE_PCM] = {
		.id = 0x600,
		.src_descr = "PCM %d",
		.src_num_offset = 1,
		.dst_descr = "PCM %02d Capture"
	},
};

/* Number of mux tables: one for each band of sample rates
 * (44.1/48kHz, 88.2/96kHz, and 176.4/176kHz)
 */
#define SCARLETT2_MUX_TABLES 3

/* Maximum number of entries in a mux table */
#define SCARLETT2_MAX_MUX_ENTRIES 10

/* One entry within mux_assignment defines the port type and range of
 * ports to add to the set_mux message. The end of the list is marked
 * with count == 0.
 */
struct scarlett2_mux_entry {
	u8 port_type;
	u8 start;
	u8 count;
};

struct scarlett2_device_info {
	u32 usb_id; /* USB device identifier */

	/* Gen 3 devices have an internal MSD mode switch that needs
	 * to be disabled in order to access the full functionality of
	 * the device.
	 */
	u8 has_msd_mode;

	/* Gen 3 devices without a mixer have a different
	 * configuration set
	 */
	u8 has_mixer;

	/* line out hw volume is sw controlled */
	u8 line_out_hw_vol;

	/* 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
	 */
	u8 level_input_count;

	/* the first input with a level control (0-based) */
	u8 level_input_first;

	/* the number of analogue inputs with a software switchable
	 * 10dB pad control
	 */
	u8 pad_input_count;

	/* the number of analogue inputs with a software switchable
	 * "air" control
	 */
	u8 air_input_count;

	/* the number of phantom (48V) software switchable controls */
	u8 phantom_count;

	/* the number of inputs each phantom switch controls */
	u8 inputs_per_phantom;

	/* the number of direct monitor options
	 * (0 = none, 1 = mono only, 2 = mono/stereo)
	 */
	u8 direct_monitor;

	/* remap analogue outputs; 18i8 Gen 3 has "line 3/4" connected
	 * internally to the analogue 7/8 outputs
	 */
	u8 line_out_remap_enable;
	u8 line_out_remap[SCARLETT2_ANALOGUE_MAX];

	/* additional description for the line out volume controls */
	const char * const line_out_descrs[SCARLETT2_ANALOGUE_MAX];

	/* number of sources/destinations of each port type */
	const int port_count[SCARLETT2_PORT_TYPE_COUNT][SCARLETT2_PORT_DIRNS];

	/* layout/order of the entries in the set_mux message */
	struct scarlett2_mux_entry mux_assignment[SCARLETT2_MUX_TABLES]
						 [SCARLETT2_MAX_MUX_ENTRIES];
};

struct scarlett2_data {
	struct usb_mixer_interface *mixer;
	struct mutex usb_mutex; /* prevent sending concurrent USB requests */
	struct mutex data_mutex; /* lock access to this data */
	struct delayed_work work;
	const struct scarlett2_device_info *info;
	__u8 bInterfaceNumber;
	__u8 bEndpointAddress;
	__u16 wMaxPacketSize;
	__u8 bInterval;
	int num_mux_srcs;
	int num_mux_dsts;
	u16 scarlett2_seq;
	u8 sync_updated;
	u8 vol_updated;
	u8 input_other_updated;
	u8 monitor_other_updated;
	u8 mux_updated;
	u8 speaker_switching_switched;
	u8 sync;
	u8 master_vol;
	u8 vol[SCARLETT2_ANALOGUE_MAX];
	u8 vol_sw_hw_switch[SCARLETT2_ANALOGUE_MAX];
	u8 mute_switch[SCARLETT2_ANALOGUE_MAX];
	u8 level_switch[SCARLETT2_LEVEL_SWITCH_MAX];
	u8 pad_switch[SCARLETT2_PAD_SWITCH_MAX];
	u8 dim_mute[SCARLETT2_DIM_MUTE_COUNT];
	u8 air_switch[SCARLETT2_AIR_SWITCH_MAX];
	u8 phantom_switch[SCARLETT2_PHANTOM_SWITCH_MAX];
	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;
	struct snd_kcontrol *vol_ctls[SCARLETT2_ANALOGUE_MAX];
	struct snd_kcontrol *sw_hw_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];
	struct snd_kcontrol *air_ctls[SCARLETT2_AIR_SWITCH_MAX];
	struct snd_kcontrol *phantom_ctls[SCARLETT2_PHANTOM_SWITCH_MAX];
	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];
};

/*** Model-specific data ***/

static const struct scarlett2_device_info s6i6_gen2_info = {
	.usb_id = USB_ID(0x1235, 0x8203),

	.has_mixer = 1,
	.level_input_count = 2,
	.pad_input_count = 2,

	.line_out_descrs = {
		"Headphones 1 L",
		"Headphones 1 R",
		"Headphones 2 L",
		"Headphones 2 R",
	},

	.port_count = {
		[SCARLETT2_PORT_TYPE_NONE]     = {  1,  0 },
		[SCARLETT2_PORT_TYPE_ANALOGUE] = {  4,  4 },
		[SCARLETT2_PORT_TYPE_SPDIF]    = {  2,  2 },
		[SCARLETT2_PORT_TYPE_MIX]      = { 10, 18 },
		[SCARLETT2_PORT_TYPE_PCM]      = {  6,  6 },
	},

	.mux_assignment = { {
		{ SCARLETT2_PORT_TYPE_PCM,      0,  6 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0,  4 },
		{ SCARLETT2_PORT_TYPE_SPDIF,    0,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,      0, 18 },
		{ SCARLETT2_PORT_TYPE_NONE,     0,  8 },
		{ 0,                            0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,      0,  6 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0,  4 },
		{ SCARLETT2_PORT_TYPE_SPDIF,    0,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,      0, 18 },
		{ SCARLETT2_PORT_TYPE_NONE,     0,  8 },
		{ 0,                            0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,      0,  6 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0,  4 },
		{ SCARLETT2_PORT_TYPE_SPDIF,    0,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,      0, 18 },
		{ SCARLETT2_PORT_TYPE_NONE,     0,  8 },
		{ 0,                            0,  0 },
	} },
};

static const struct scarlett2_device_info s18i8_gen2_info = {
	.usb_id = USB_ID(0x1235, 0x8204),

	.has_mixer = 1,
	.level_input_count = 2,
	.pad_input_count = 4,

	.line_out_descrs = {
		"Monitor L",
		"Monitor R",
		"Headphones 1 L",
		"Headphones 1 R",
		"Headphones 2 L",
		"Headphones 2 R",
	},

	.port_count = {
		[SCARLETT2_PORT_TYPE_NONE]     = {  1,  0 },
		[SCARLETT2_PORT_TYPE_ANALOGUE] = {  8,  6 },
		[SCARLETT2_PORT_TYPE_SPDIF]    = {  2,  2 },
		[SCARLETT2_PORT_TYPE_ADAT]     = {  8,  0 },
		[SCARLETT2_PORT_TYPE_MIX]      = { 10, 18 },
		[SCARLETT2_PORT_TYPE_PCM]      = {  8, 18 },
	},

	.mux_assignment = { {
		{ SCARLETT2_PORT_TYPE_PCM,      0, 18 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0,  6 },
		{ SCARLETT2_PORT_TYPE_SPDIF,    0,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,      0, 18 },
		{ SCARLETT2_PORT_TYPE_NONE,     0,  8 },
		{ 0,                            0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,      0, 14 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0,  6 },
		{ SCARLETT2_PORT_TYPE_SPDIF,    0,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,      0, 18 },
		{ SCARLETT2_PORT_TYPE_NONE,     0,  8 },
		{ 0,                            0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,      0, 10 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0,  6 },
		{ SCARLETT2_PORT_TYPE_SPDIF,    0,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,      0, 18 },
		{ SCARLETT2_PORT_TYPE_NONE,     0,  4 },
		{ 0,                            0,  0 },
	} },
};

static const struct scarlett2_device_info s18i20_gen2_info = {
	.usb_id = USB_ID(0x1235, 0x8201),

	.has_mixer = 1,
	.line_out_hw_vol = 1,

	.line_out_descrs = {
		"Monitor L",
		"Monitor R",
		NULL,
		NULL,
		NULL,
		NULL,
		"Headphones 1 L",
		"Headphones 1 R",
		"Headphones 2 L",
		"Headphones 2 R",
	},

	.port_count = {
		[SCARLETT2_PORT_TYPE_NONE]     = {  1,  0 },
		[SCARLETT2_PORT_TYPE_ANALOGUE] = {  8, 10 },
		[SCARLETT2_PORT_TYPE_SPDIF]    = {  2,  2 },
		[SCARLETT2_PORT_TYPE_ADAT]     = {  8,  8 },
		[SCARLETT2_PORT_TYPE_MIX]      = { 10, 18 },
		[SCARLETT2_PORT_TYPE_PCM]      = { 20, 18 },
	},

	.mux_assignment = { {
		{ SCARLETT2_PORT_TYPE_PCM,      0, 18 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0, 10 },
		{ SCARLETT2_PORT_TYPE_SPDIF,    0,  2 },
		{ SCARLETT2_PORT_TYPE_ADAT,     0,  8 },
		{ SCARLETT2_PORT_TYPE_MIX,      0, 18 },
		{ SCARLETT2_PORT_TYPE_NONE,     0,  8 },
		{ 0,                            0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,      0, 14 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0, 10 },
		{ SCARLETT2_PORT_TYPE_SPDIF,    0,  2 },
		{ SCARLETT2_PORT_TYPE_ADAT,     0,  4 },
		{ SCARLETT2_PORT_TYPE_MIX,      0, 18 },
		{ SCARLETT2_PORT_TYPE_NONE,     0,  8 },
		{ 0,                            0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,      0, 10 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0, 10 },
		{ SCARLETT2_PORT_TYPE_SPDIF,    0,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,      0, 18 },
		{ SCARLETT2_PORT_TYPE_NONE,     0,  6 },
		{ 0,                            0,  0 },
	} },
};

static const struct scarlett2_device_info solo_gen3_info = {
	.usb_id = USB_ID(0x1235, 0x8211),

	.has_msd_mode = 1,
	.level_input_count = 1,
	.level_input_first = 1,
	.air_input_count = 1,
	.phantom_count = 1,
	.inputs_per_phantom = 1,
	.direct_monitor = 1,
};

static const struct scarlett2_device_info s2i2_gen3_info = {
	.usb_id = USB_ID(0x1235, 0x8210),

	.has_msd_mode = 1,
	.level_input_count = 2,
	.air_input_count = 2,
	.phantom_count = 1,
	.inputs_per_phantom = 2,
	.direct_monitor = 2,
};

static const struct scarlett2_device_info s4i4_gen3_info = {
	.usb_id = USB_ID(0x1235, 0x8212),

	.has_msd_mode = 1,
	.has_mixer = 1,
	.level_input_count = 2,
	.pad_input_count = 2,
	.air_input_count = 2,
	.phantom_count = 1,
	.inputs_per_phantom = 2,

	.line_out_descrs = {
		"Monitor L",
		"Monitor R",
		"Headphones L",
		"Headphones R",
	},

	.port_count = {
		[SCARLETT2_PORT_TYPE_NONE]     = { 1, 0 },
		[SCARLETT2_PORT_TYPE_ANALOGUE] = { 4, 4 },
		[SCARLETT2_PORT_TYPE_MIX]      = { 6, 8 },
		[SCARLETT2_PORT_TYPE_PCM]      = { 4, 6 },
	},

	.mux_assignment = { {
		{ SCARLETT2_PORT_TYPE_PCM,      0,  6 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0,  4 },
		{ SCARLETT2_PORT_TYPE_MIX,      0,  8 },
		{ SCARLETT2_PORT_TYPE_NONE,     0, 16 },
		{ 0,                            0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,      0,  6 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0,  4 },
		{ SCARLETT2_PORT_TYPE_MIX,      0,  8 },
		{ SCARLETT2_PORT_TYPE_NONE,     0, 16 },
		{ 0,                            0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,      0,  6 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0,  4 },
		{ SCARLETT2_PORT_TYPE_MIX,      0,  8 },
		{ SCARLETT2_PORT_TYPE_NONE,     0, 16 },
		{ 0,                            0,  0 },
	} },
};

static const struct scarlett2_device_info s8i6_gen3_info = {
	.usb_id = USB_ID(0x1235, 0x8213),

	.has_msd_mode = 1,
	.has_mixer = 1,
	.level_input_count = 2,
	.pad_input_count = 2,
	.air_input_count = 2,
	.phantom_count = 1,
	.inputs_per_phantom = 2,

	.line_out_descrs = {
		"Headphones 1 L",
		"Headphones 1 R",
		"Headphones 2 L",
		"Headphones 2 R",
	},

	.port_count = {
		[SCARLETT2_PORT_TYPE_NONE]     = { 1,  0 },
		[SCARLETT2_PORT_TYPE_ANALOGUE] = { 6,  4 },
		[SCARLETT2_PORT_TYPE_SPDIF]    = { 2,  2 },
		[SCARLETT2_PORT_TYPE_MIX]      = { 8,  8 },
		[SCARLETT2_PORT_TYPE_PCM]      = { 6, 10 },
	},

	.mux_assignment = { {
		{ SCARLETT2_PORT_TYPE_PCM,      0,  8 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0,  4 },
		{ SCARLETT2_PORT_TYPE_SPDIF,    0,  2 },
		{ SCARLETT2_PORT_TYPE_PCM,      8,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,      0,  8 },
		{ SCARLETT2_PORT_TYPE_NONE,     0, 18 },
		{ 0,                            0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,      0,  8 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0,  4 },
		{ SCARLETT2_PORT_TYPE_SPDIF,    0,  2 },
		{ SCARLETT2_PORT_TYPE_PCM,      8,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,      0,  8 },
		{ SCARLETT2_PORT_TYPE_NONE,     0, 18 },
		{ 0,                            0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,      0,  8 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE, 0,  4 },
		{ SCARLETT2_PORT_TYPE_SPDIF,    0,  2 },
		{ SCARLETT2_PORT_TYPE_PCM,      8,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,      0,  8 },
		{ SCARLETT2_PORT_TYPE_NONE,     0, 18 },
		{ 0,                            0,  0 },
	} },
};

static const struct scarlett2_device_info s18i8_gen3_info = {
	.usb_id = USB_ID(0x1235, 0x8214),

	.has_msd_mode = 1,
	.has_mixer = 1,
	.line_out_hw_vol = 1,
	.has_speaker_switching = 1,
	.level_input_count = 2,
	.pad_input_count = 4,
	.air_input_count = 4,
	.phantom_count = 2,
	.inputs_per_phantom = 2,

	.line_out_remap_enable = 1,
	.line_out_remap = { 0, 1, 6, 7, 2, 3, 4, 5 },

	.line_out_descrs = {
		"Monitor L",
		"Monitor R",
		"Alt Monitor L",
		"Alt Monitor R",
		"Headphones 1 L",
		"Headphones 1 R",
		"Headphones 2 L",
		"Headphones 2 R",
	},

	.port_count = {
		[SCARLETT2_PORT_TYPE_NONE]     = {  1,  0 },
		[SCARLETT2_PORT_TYPE_ANALOGUE] = {  8,  8 },
		[SCARLETT2_PORT_TYPE_SPDIF]    = {  2,  2 },
		[SCARLETT2_PORT_TYPE_ADAT]     = {  8,  0 },
		[SCARLETT2_PORT_TYPE_MIX]      = { 10, 20 },
		[SCARLETT2_PORT_TYPE_PCM]      = {  8, 20 },
	},

	.mux_assignment = { {
		{ SCARLETT2_PORT_TYPE_PCM,       0, 10 },
		{ SCARLETT2_PORT_TYPE_PCM,      12,  8 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE,  0,  2 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE,  6,  2 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE,  2,  4 },
		{ SCARLETT2_PORT_TYPE_SPDIF,     0,  2 },
		{ SCARLETT2_PORT_TYPE_PCM,      10,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,       0, 20 },
		{ SCARLETT2_PORT_TYPE_NONE,      0, 10 },
		{ 0,                             0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,       0, 10 },
		{ SCARLETT2_PORT_TYPE_PCM,      12,  4 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE,  0,  2 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE,  6,  2 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE,  2,  4 },
		{ SCARLETT2_PORT_TYPE_SPDIF,     0,  2 },
		{ SCARLETT2_PORT_TYPE_PCM,      10,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,       0, 20 },
		{ SCARLETT2_PORT_TYPE_NONE,      0, 10 },
		{ 0,                             0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,       0, 10 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE,  0,  2 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE,  6,  2 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE,  2,  4 },
		{ SCARLETT2_PORT_TYPE_SPDIF,     0,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,       0, 20 },
		{ SCARLETT2_PORT_TYPE_NONE,      0, 10 },
		{ 0,                             0,  0 },
	} },
};

static const struct scarlett2_device_info s18i20_gen3_info = {
	.usb_id = USB_ID(0x1235, 0x8215),

	.has_msd_mode = 1,
	.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,
	.phantom_count = 2,
	.inputs_per_phantom = 4,

	.line_out_descrs = {
		"Monitor 1 L",
		"Monitor 1 R",
		"Monitor 2 L",
		"Monitor 2 R",
		NULL,
		NULL,
		"Headphones 1 L",
		"Headphones 1 R",
		"Headphones 2 L",
		"Headphones 2 R",
	},

	.port_count = {
		[SCARLETT2_PORT_TYPE_NONE]     = {  1,  0 },
		[SCARLETT2_PORT_TYPE_ANALOGUE] = {  9, 10 },
		[SCARLETT2_PORT_TYPE_SPDIF]    = {  2,  2 },
		[SCARLETT2_PORT_TYPE_ADAT]     = {  8,  8 },
		[SCARLETT2_PORT_TYPE_MIX]      = { 12, 25 },
		[SCARLETT2_PORT_TYPE_PCM]      = { 20, 20 },
	},

	.mux_assignment = { {
		{ SCARLETT2_PORT_TYPE_PCM,       0,  8 },
		{ SCARLETT2_PORT_TYPE_PCM,      10, 10 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE,  0, 10 },
		{ SCARLETT2_PORT_TYPE_SPDIF,     0,  2 },
		{ SCARLETT2_PORT_TYPE_ADAT,      0,  8 },
		{ SCARLETT2_PORT_TYPE_PCM,       8,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,       0, 25 },
		{ SCARLETT2_PORT_TYPE_NONE,      0, 12 },
		{ 0,                             0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,       0,  8 },
		{ SCARLETT2_PORT_TYPE_PCM,      10,  8 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE,  0, 10 },
		{ SCARLETT2_PORT_TYPE_SPDIF,     0,  2 },
		{ SCARLETT2_PORT_TYPE_ADAT,      0,  8 },
		{ SCARLETT2_PORT_TYPE_PCM,       8,  2 },
		{ SCARLETT2_PORT_TYPE_MIX,       0, 25 },
		{ SCARLETT2_PORT_TYPE_NONE,      0, 10 },
		{ 0,                             0,  0 },
	}, {
		{ SCARLETT2_PORT_TYPE_PCM,       0, 10 },
		{ SCARLETT2_PORT_TYPE_ANALOGUE,  0, 10 },
		{ SCARLETT2_PORT_TYPE_SPDIF,     0,  2 },
		{ SCARLETT2_PORT_TYPE_NONE,      0, 24 },
		{ 0,                             0,  0 },
	} },
};

static const struct scarlett2_device_info *scarlett2_devices[] = {
	/* Supported Gen 2 devices */
	&s6i6_gen2_info,
	&s18i8_gen2_info,
	&s18i20_gen2_info,

	/* Supported Gen 3 devices */
	&solo_gen3_info,
	&s2i2_gen3_info,
	&s4i4_gen3_info,
	&s8i6_gen3_info,
	&s18i8_gen3_info,
	&s18i20_gen3_info,

	/* End of list */
	NULL
};

/* get the starting port index number for a given port type/direction */
static int scarlett2_get_port_start_num(
	const int port_count[][SCARLETT2_PORT_DIRNS],
	int direction, int port_type)
{
	int i, num = 0;

	for (i = 0; i < port_type; i++)
		num += port_count[i][direction];

	return 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_INPUT_OTHER   0x00800000
#define SCARLETT2_USB_NOTIFY_MONITOR_OTHER 0x01000000

/* Commands for sending/receiving requests/responses */
#define SCARLETT2_USB_CMD_INIT 0
#define SCARLETT2_USB_CMD_REQ  2
#define SCARLETT2_USB_CMD_RESP 3

#define SCARLETT2_USB_INIT_1    0x00000000
#define SCARLETT2_USB_INIT_2    0x00000002
#define SCARLETT2_USB_GET_METER 0x00001001
#define SCARLETT2_USB_GET_MIX   0x00002001
#define SCARLETT2_USB_SET_MIX   0x00002002
#define SCARLETT2_USB_GET_MUX   0x00003001
#define SCARLETT2_USB_SET_MUX   0x00003002
#define SCARLETT2_USB_GET_SYNC  0x00006004
#define SCARLETT2_USB_GET_DATA  0x00800000
#define SCARLETT2_USB_SET_DATA  0x00800001
#define SCARLETT2_USB_DATA_CMD  0x00800002

#define SCARLETT2_USB_CONFIG_SAVE 6

#define SCARLETT2_USB_VOLUME_STATUS_OFFSET 0x31
#define SCARLETT2_USB_METER_LEVELS_GET_MAGIC 1

/* volume status is read together (matches scarlett2_config_items[1]) */
struct scarlett2_usb_volume_status {
	/* dim/mute buttons */
	u8 dim_mute[SCARLETT2_DIM_MUTE_COUNT];

	u8 pad1;

	/* software volume setting */
	s16 sw_vol[SCARLETT2_ANALOGUE_MAX];

	/* actual volume of output inc. dim (-18dB) */
	s16 hw_vol[SCARLETT2_ANALOGUE_MAX];

	/* internal mute buttons */
	u8 mute_switch[SCARLETT2_ANALOGUE_MAX];

	/* sw (0) or hw (1) controlled */
	u8 sw_hw_switch[SCARLETT2_ANALOGUE_MAX];

	u8 pad3[6];

	/* front panel volume knob */
	s16 master_vol;
} __packed;

/* Configuration parameters that can be read and written */
enum {
	SCARLETT2_CONFIG_DIM_MUTE = 0,
	SCARLETT2_CONFIG_LINE_OUT_VOLUME = 1,
	SCARLETT2_CONFIG_MUTE_SWITCH = 2,
	SCARLETT2_CONFIG_SW_HW_SWITCH = 3,
	SCARLETT2_CONFIG_LEVEL_SWITCH = 4,
	SCARLETT2_CONFIG_PAD_SWITCH = 5,
	SCARLETT2_CONFIG_MSD_SWITCH = 6,
	SCARLETT2_CONFIG_AIR_SWITCH = 7,
	SCARLETT2_CONFIG_PHANTOM_SWITCH = 8,
	SCARLETT2_CONFIG_PHANTOM_PERSISTENCE = 9,
	SCARLETT2_CONFIG_DIRECT_MONITOR = 10,
	SCARLETT2_CONFIG_MONITOR_OTHER_SWITCH = 11,
	SCARLETT2_CONFIG_MONITOR_OTHER_ENABLE = 12,
	SCARLETT2_CONFIG_TALKBACK_MAP = 13,
	SCARLETT2_CONFIG_COUNT = 14
};

/* Location, size, and activation command number for the configuration
 * parameters. Size is in bits and may be 1, 8, or 16.
 */
struct scarlett2_config {
	u8 offset;
	u8 size;
	u8 activate;
};

/* scarlett2_config_items[0] is for devices without a mixer
 * scarlett2_config_items[1] is for devices with a mixer
 */
static const struct scarlett2_config
	scarlett2_config_items[2][SCARLETT2_CONFIG_COUNT] =

/* Devices without a mixer (Solo and 2i2 Gen 3) */
{ {
	[SCARLETT2_CONFIG_MSD_SWITCH] = {
		.offset = 0x04, .size = 8, .activate = 6 },

	[SCARLETT2_CONFIG_PHANTOM_PERSISTENCE] = {
		.offset = 0x05, .size = 8, .activate = 6 },

	[SCARLETT2_CONFIG_PHANTOM_SWITCH] = {
		.offset = 0x06, .size = 8, .activate = 3 },

	[SCARLETT2_CONFIG_DIRECT_MONITOR] = {
		.offset = 0x07, .size = 8, .activate = 4 },

	[SCARLETT2_CONFIG_LEVEL_SWITCH] = {
		.offset = 0x08, .size = 1, .activate = 7 },

	[SCARLETT2_CONFIG_AIR_SWITCH] = {
		.offset = 0x09, .size = 1, .activate = 8 },

/* Devices with a mixer (Gen 2 and all other Gen 3) */
}, {
	[SCARLETT2_CONFIG_DIM_MUTE] = {
		.offset = 0x31, .size = 8, .activate = 2 },

	[SCARLETT2_CONFIG_LINE_OUT_VOLUME] = {
		.offset = 0x34, .size = 16, .activate = 1 },

	[SCARLETT2_CONFIG_MUTE_SWITCH] = {
		.offset = 0x5c, .size = 8, .activate = 1 },

	[SCARLETT2_CONFIG_SW_HW_SWITCH] = {
		.offset = 0x66, .size = 8, .activate = 3 },

	[SCARLETT2_CONFIG_LEVEL_SWITCH] = {
		.offset = 0x7c, .size = 8, .activate = 7 },

	[SCARLETT2_CONFIG_PAD_SWITCH] = {
		.offset = 0x84, .size = 8, .activate = 8 },

	[SCARLETT2_CONFIG_AIR_SWITCH] = {
		.offset = 0x8c, .size = 8, .activate = 8 },

	[SCARLETT2_CONFIG_PHANTOM_SWITCH] = {
		.offset = 0x9c, .size = 1, .activate = 8 },

	[SCARLETT2_CONFIG_MSD_SWITCH] = {
		.offset = 0x9d, .size = 8, .activate = 6 },