sound/firewire/motu/motu-protocol-v1.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 // motu-protocol-v1.c - a part of driver for MOTU FireWire series
 //
 // Copyright (c) 2021 Takashi Sakamoto <o-takashi@sakamocchi.jp>

 #include "motu.h"

 #include <linux/delay.h>

 // Status register for MOTU 828 (0x'ffff'f000'0b00).
 //
 // 0xffff0000: ISOC_COMM_CONTROL_MASK in motu-stream.c.
 // 0x00008000: mode of optical input interface.
 //   0x00008000: for S/PDIF signal.
 //   0x00000000: disabled or for ADAT signal.
 // 0x00004000: mode of optical output interface.
 //   0x00004000: for S/PDIF signal.
 //   0x00000000: disabled or for ADAT signal.
 // 0x00003f00: monitor input mode.
 //   0x00000800: analog-1/2
 //   0x00001a00: analog-3/4
 //   0x00002c00: analog-5/6
 //   0x00003e00: analog-7/8
 //   0x00000000: analog-1
 //   0x00000900: analog-2
 //   0x00001200: analog-3
 //   0x00001b00: analog-4
 //   0x00002400: analog-5
 //   0x00002d00: analog-6
 //   0x00003600: analog-7
 //   0x00003f00: analog-8
 // 0x00000080: enable stream input.
 // 0x00000040: disable monitor input.
 // 0x00000008: enable main out.
 // 0x00000004: rate of sampling clock.
 //   0x00000004: 48.0 kHz
 //   0x00000000: 44.1 kHz
 // 0x00000023: source of sampling clock.
 //   0x00000003: source packet header (SPH)
 //   0x00000002: S/PDIF on optical/coaxial interface.
 //   0x00000021: ADAT on optical interface
 //   0x00000001: ADAT on Dsub 9pin
 //   0x00000000: internal

 #define CLK_828_STATUS_OFFSET				0x0b00
 #define  CLK_828_STATUS_MASK				0x0000ffff
 #define  CLK_828_STATUS_FLAG_OPT_IN_IFACE_IS_SPDIF	0x00008000
 #define  CLK_828_STATUS_FLAG_OPT_OUT_IFACE_IS_SPDIF	0x00004000
 #define  CLK_828_STATUS_FLAG_FETCH_PCM_FRAMES		0x00000080
 #define  CLK_828_STATUS_FLAG_ENABLE_OUTPUT		0x00000008
 #define  CLK_828_STATUS_FLAG_RATE_48000			0x00000004
 #define  CLK_828_STATUS_MASK_SRC			0x00000023
 #define   CLK_828_STATUS_FLAG_SRC_ADAT_ON_OPT		0x00000021
 #define   CLK_828_STATUS_FLAG_SRC_SPH			0x00000003
 #define   CLK_828_STATUS_FLAG_SRC_SPDIF			0x00000002
 #define   CLK_828_STATUS_FLAG_SRC_ADAT_ON_DSUB		0x00000001
 #define   CLK_828_STATUS_FLAG_SRC_INTERNAL		0x00000000

 // Status register for MOTU 896 (0x'ffff'f000'0b14).
 //
 // 0xf0000000: enable physical and stream input to DAC.
 //   0x80000000: disable
 //   0x40000000: disable
 //   0x20000000: enable (prior to the other bits)
 //   0x10000000: disable
 //   0x00000000: disable
 // 0x08000000: speed of word clock signal output on BNC interface.
 //   0x00000000: force to low rate (44.1/48.0 kHz).
 //   0x08000000: follow to system clock.
 // 0x04000000: something relevant to clock.
 // 0x03000000: enable output.
 //  0x02000000: enabled irreversibly once standing unless the device voluntarily disables it.
 //  0x01000000: enabled irreversibly once standing unless the device voluntarily disables it.
 // 0x00ffff00: monitor input mode.
 //   0x00000000: disabled
 //   0x00004800: analog-1/2
 //   0x00005a00: analog-3/4
 //   0x00006c00: analog-5/6
 //   0x00007e00: analog-7/8
 //   0x00104800: AES/EBU-1/2
 //   0x00004000: analog-1
 //   0x00004900: analog-2
 //   0x00005200: analog-3
 //   0x00005b00: analog-4
 //   0x00006400: analog-5
 //   0x00006d00: analog-6
 //   0x00007600: analog-7
 //   0x00007f00: analog-8
 //   0x00104000: AES/EBU-1
 //   0x00104900: AES/EBU-2
 // 0x00000060: sample rate conversion for AES/EBU input/output.
 //   0x00000000: None
 //   0x00000020: input signal is converted to system rate
 //   0x00000040: output is slave to input, ignoring system rate
 //   0x00000060: output is double rate than system rate
 // 0x00000018: nominal rate of sampling clock.
 //   0x00000000: 44.1 kHz
 //   0x00000008: 48.0 kHz
 //   0x00000010: 88.2 kHz
 //   0x00000018: 96.0 kHz
 // 0x00000007: source of sampling clock.
 //   0x00000000: internal
 //   0x00000001: ADAT on optical interface
 //   0x00000002: AES/EBU on XLR
 //   0x00000003: source packet header (SPH)
 //   0x00000004: word clock on BNC
 //   0x00000005: ADAT on Dsub 9pin

 #define CLK_896_STATUS_OFFSET			0x0b14
 #define  CLK_896_STATUS_FLAG_FETCH_ENABLE	0x20000000
 #define  CLK_896_STATUS_FLAG_OUTPUT_ON		0x03000000
 #define  CLK_896_STATUS_MASK_SRC		0x00000007
 #define   CLK_896_STATUS_FLAG_SRC_INTERNAL	0x00000000
 #define   CLK_896_STATUS_FLAG_SRC_ADAT_ON_OPT	0x00000001
 #define   CLK_896_STATUS_FLAG_SRC_AESEBU	0x00000002
 #define   CLK_896_STATUS_FLAG_SRC_SPH		0x00000003
 #define   CLK_896_STATUS_FLAG_SRC_WORD		0x00000004
 #define   CLK_896_STATUS_FLAG_SRC_ADAT_ON_DSUB	0x00000005
 #define  CLK_896_STATUS_MASK_RATE		0x00000018
 #define   CLK_896_STATUS_FLAG_RATE_44100	0x00000000
 #define   CLK_896_STATUS_FLAG_RATE_48000	0x00000008
 #define   CLK_896_STATUS_FLAG_RATE_88200	0x00000010
 #define   CLK_896_STATUS_FLAG_RATE_96000	0x00000018

 static void parse_clock_rate_828(u32 data, unsigned int *rate)
 {
 	if (data & CLK_828_STATUS_FLAG_RATE_48000)
 		*rate = 48000;
 	else
 		*rate = 44100;
 }

 static int get_clock_rate_828(struct snd_motu *motu, unsigned int *rate)
 {
 	__be32 reg;
 	int err;

 	err = snd_motu_transaction_read(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
 	if (err < 0)
 		return err;
 	parse_clock_rate_828(be32_to_cpu(reg), rate);

 	return 0;
 }

 static int parse_clock_rate_896(u32 data, unsigned int *rate)
 {
 	switch (data & CLK_896_STATUS_MASK_RATE) {
 	case CLK_896_STATUS_FLAG_RATE_44100:
 		*rate = 44100;
 		break;
 	case CLK_896_STATUS_FLAG_RATE_48000:
 		*rate = 48000;
 		break;
 	case CLK_896_STATUS_FLAG_RATE_88200:
 		*rate = 88200;
 		break;
 	case CLK_896_STATUS_FLAG_RATE_96000:
 		*rate = 96000;
 		break;
 	default:
 		return -ENXIO;
 	}

 	return 0;
 }

 static int get_clock_rate_896(struct snd_motu *motu, unsigned int *rate)
 {
 	__be32 reg;
 	int err;

 	err = snd_motu_transaction_read(motu, CLK_896_STATUS_OFFSET, &reg, sizeof(reg));
 	if (err < 0)
 		return err;
 	return parse_clock_rate_896(be32_to_cpu(reg), rate);
 }

 int snd_motu_protocol_v1_get_clock_rate(struct snd_motu *motu, unsigned int *rate)
 {
 	if (motu->spec == &snd_motu_spec_828)
 		return get_clock_rate_828(motu, rate);
 	else if (motu->spec == &snd_motu_spec_896)
 		return get_clock_rate_896(motu, rate);
 	else
 		return -ENXIO;
 }

 static int set_clock_rate_828(struct snd_motu *motu, unsigned int rate)
 {
 	__be32 reg;
 	u32 data;
 	int err;

 	err = snd_motu_transaction_read(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
 	if (err < 0)
 		return err;
 	data = be32_to_cpu(reg) & CLK_828_STATUS_MASK;

 	data &= ~CLK_828_STATUS_FLAG_RATE_48000;
 	if (rate == 48000)
 		data |= CLK_828_STATUS_FLAG_RATE_48000;

 	reg = cpu_to_be32(data);
 	return snd_motu_transaction_write(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
 }

 static int set_clock_rate_896(struct snd_motu *motu, unsigned int rate)
 {
 	unsigned int flag;
 	__be32 reg;
 	u32 data;
 	int err;

 	err = snd_motu_transaction_read(motu, CLK_896_STATUS_OFFSET, &reg, sizeof(reg));
 	if (err < 0)
 		return err;
 	data = be32_to_cpu(reg);

 	switch (rate) {
 	case 44100:
 		flag = CLK_896_STATUS_FLAG_RATE_44100;
 		break;
 	case 48000:
 		flag = CLK_896_STATUS_FLAG_RATE_48000;
 		break;
 	case 88200:
 		flag = CLK_896_STATUS_FLAG_RATE_88200;
 		break;
 	case 96000:
 		flag = CLK_896_STATUS_FLAG_RATE_96000;
 		break;
 	default:
 		return -EINVAL;
 	}

 	data &= ~CLK_896_STATUS_MASK_RATE;
 	data |= flag;

 	reg = cpu_to_be32(data);
 	return snd_motu_transaction_write(motu, CLK_896_STATUS_OFFSET, &reg, sizeof(reg));
 }

 int snd_motu_protocol_v1_set_clock_rate(struct snd_motu *motu, unsigned int rate)
 {
 	if (motu->spec == &snd_motu_spec_828)
 		return set_clock_rate_828(motu, rate);
 	else if (motu->spec == &snd_motu_spec_896)
 		return set_clock_rate_896(motu, rate);
 	else
 		return -ENXIO;
 }

 static int get_clock_source_828(struct snd_motu *motu, enum snd_motu_clock_source *src)
 {
 	__be32 reg;
 	u32 data;
 	int err;

 	err = snd_motu_transaction_read(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
 	if (err < 0)
 		return err;
 	data = be32_to_cpu(reg) & CLK_828_STATUS_MASK;

 	switch (data & CLK_828_STATUS_MASK_SRC) {
 	case CLK_828_STATUS_FLAG_SRC_ADAT_ON_OPT:
 		*src = SND_MOTU_CLOCK_SOURCE_ADAT_ON_OPT;
 		break;
 	case CLK_828_STATUS_FLAG_SRC_SPH:
 		*src = SND_MOTU_CLOCK_SOURCE_SPH;
 		break;
 	case CLK_828_STATUS_FLAG_SRC_SPDIF:
 	{
 		if (data & CLK_828_STATUS_FLAG_OPT_IN_IFACE_IS_SPDIF)
 			*src = SND_MOTU_CLOCK_SOURCE_SPDIF_ON_COAX;
 		else
 			*src = SND_MOTU_CLOCK_SOURCE_SPDIF_ON_OPT;
 		break;
 	}
 	case CLK_828_STATUS_FLAG_SRC_ADAT_ON_DSUB:
 		*src = SND_MOTU_CLOCK_SOURCE_ADAT_ON_DSUB;
 		break;
 	case CLK_828_STATUS_FLAG_SRC_INTERNAL:
 		*src = SND_MOTU_CLOCK_SOURCE_INTERNAL;
 		break;
 	default:
 		return -ENXIO;
 	}

 	return 0;
 }

 static int get_clock_source_896(struct snd_motu *motu, enum snd_motu_clock_source *src)
 {
 	__be32 reg;
 	u32 data;
 	int err;

 	err = snd_motu_transaction_read(motu, CLK_896_STATUS_OFFSET, &reg, sizeof(reg));
 	if (err < 0)
 		return err;
 	data = be32_to_cpu(reg);

 	switch (data & CLK_896_STATUS_MASK_SRC) {
 	case CLK_896_STATUS_FLAG_SRC_INTERNAL:
 		*src = SND_MOTU_CLOCK_SOURCE_INTERNAL;
 		break;
 	case CLK_896_STATUS_FLAG_SRC_ADAT_ON_OPT:
 		*src = SND_MOTU_CLOCK_SOURCE_ADAT_ON_OPT;
 		break;
 	case CLK_896_STATUS_FLAG_SRC_AESEBU:
 		*src = SND_MOTU_CLOCK_SOURCE_AESEBU_ON_XLR;
 		break;
 	case CLK_896_STATUS_FLAG_SRC_SPH:
 		*src = SND_MOTU_CLOCK_SOURCE_SPH;
 		break;
 	case CLK_896_STATUS_FLAG_SRC_WORD:
 		*src = SND_MOTU_CLOCK_SOURCE_WORD_ON_BNC;
 		break;
 	case CLK_896_STATUS_FLAG_SRC_ADAT_ON_DSUB:
 		*src = SND_MOTU_CLOCK_SOURCE_ADAT_ON_DSUB;
 		break;
 	default:
 		return -ENXIO;
 	}

 	return 0;
 }

 int snd_motu_protocol_v1_get_clock_source(struct snd_motu *motu, enum snd_motu_clock_source *src)
 {
 	if (motu->spec == &snd_motu_spec_828)
 		return get_clock_source_828(motu, src);
 	else if (motu->spec == &snd_motu_spec_896)
 		return get_clock_source_896(motu, src);
 	else
 		return -ENXIO;
 }

 static int switch_fetching_mode_828(struct snd_motu *motu, bool enable)
 {
 	__be32 reg;
 	u32 data;
 	int err;

 	err = snd_motu_transaction_read(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
 	if (err < 0)
 		return err;
 	data = be32_to_cpu(reg) & CLK_828_STATUS_MASK;

 	data &= ~(CLK_828_STATUS_FLAG_FETCH_PCM_FRAMES | CLK_828_STATUS_FLAG_ENABLE_OUTPUT);
 	if (enable) {
 		// This transaction should be initiated after the device receives batch of packets
 		// since the device voluntarily mutes outputs. As a workaround, yield processor over
 		// 100 msec.
 		msleep(100);
 		data |= CLK_828_STATUS_FLAG_FETCH_PCM_FRAMES | CLK_828_STATUS_FLAG_ENABLE_OUTPUT;
 	}

 	reg = cpu_to_be32(data);
 	return snd_motu_transaction_write(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
 }

 static int switch_fetching_mode_896(struct snd_motu *motu, bool enable)
 {
 	__be32 reg;
 	u32 data;
 	int err;

 	err = snd_motu_transaction_read(motu, CLK_896_STATUS_OFFSET, &reg, sizeof(reg));
 	if (err < 0)
 		return err;
 	data = be32_to_cpu(reg);

 	data &= ~CLK_896_STATUS_FLAG_FETCH_ENABLE;
 	if (enable)
 		data |= CLK_896_STATUS_FLAG_FETCH_ENABLE | CLK_896_STATUS_FLAG_OUTPUT_ON;

 	reg = cpu_to_be32(data);
 	return snd_motu_transaction_write(motu, CLK_896_STATUS_OFFSET, &reg, sizeof(reg));
 }

 int snd_motu_protocol_v1_switch_fetching_mode(struct snd_motu *motu, bool enable)
 {
 	if (motu->spec == &snd_motu_spec_828)
 		return switch_fetching_mode_828(motu, enable);
 	else if (motu->spec == &snd_motu_spec_896)
 		return switch_fetching_mode_896(motu, enable);
 	else
 		return -ENXIO;
 }

 static int detect_packet_formats_828(struct snd_motu *motu)
 {
 	__be32 reg;
 	u32 data;
 	int err;

 	motu->tx_packet_formats.pcm_byte_offset = 4;
 	motu->tx_packet_formats.msg_chunks = 2;

 	motu->rx_packet_formats.pcm_byte_offset = 4;
 	motu->rx_packet_formats.msg_chunks = 0;

 	err = snd_motu_transaction_read(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
 	if (err < 0)
 		return err;
 	data = be32_to_cpu(reg) & CLK_828_STATUS_MASK;

 	// The number of chunks is just reduced when SPDIF is activated.
 	if (!(data & CLK_828_STATUS_FLAG_OPT_IN_IFACE_IS_SPDIF))
 		motu->tx_packet_formats.pcm_chunks[0] += 8;

 	if (!(data & CLK_828_STATUS_FLAG_OPT_OUT_IFACE_IS_SPDIF))
 		motu->rx_packet_formats.pcm_chunks[0] += 8;

 	return 0;
 }

 static int detect_packet_formats_896(struct snd_motu *motu)
 {
 	// 24bit PCM frames follow to source packet header without message chunk.
 	motu->tx_packet_formats.pcm_byte_offset = 4;
 	motu->rx_packet_formats.pcm_byte_offset = 4;

 	// No message chunk in data block.
 	motu->tx_packet_formats.msg_chunks = 0;
 	motu->rx_packet_formats.msg_chunks = 0;

 	// Always enable optical interface for ADAT signal since the device have no registers
 	// to refer to current configuration.
 	motu->tx_packet_formats.pcm_chunks[0] += 8;
 	motu->tx_packet_formats.pcm_chunks[1] += 8;

 	motu->rx_packet_formats.pcm_chunks[0] += 8;
 	motu->rx_packet_formats.pcm_chunks[1] += 8;

 	return 0;
 }

 int snd_motu_protocol_v1_cache_packet_formats(struct snd_motu *motu)
 {
 	memcpy(motu->tx_packet_formats.pcm_chunks, motu->spec->tx_fixed_pcm_chunks,
 	       sizeof(motu->tx_packet_formats.pcm_chunks));
 	memcpy(motu->rx_packet_formats.pcm_chunks, motu->spec->rx_fixed_pcm_chunks,
 	       sizeof(motu->rx_packet_formats.pcm_chunks));

 	if (motu->spec == &snd_motu_spec_828)
 		return detect_packet_formats_828(motu);
 	else if (motu->spec == &snd_motu_spec_896)
 		return detect_packet_formats_896(motu);
 	else
 		return 0;
 }

 const struct snd_motu_spec snd_motu_spec_828 = {
 	.name = "828",
 	.protocol_version = SND_MOTU_PROTOCOL_V1,
 	.tx_fixed_pcm_chunks = {10, 0, 0},
 	.rx_fixed_pcm_chunks = {10, 0, 0},
 };

 const struct snd_motu_spec snd_motu_spec_896 = {
 	.name = "896",
 	.tx_fixed_pcm_chunks = {10, 10, 0},
 	.rx_fixed_pcm_chunks = {10, 10, 0},
 };
	// SPDX-License-Identifier: GPL-2.0-only
	// motu-protocol-v1.c - a part of driver for MOTU FireWire series
	//
	// Copyright (c) 2021 Takashi Sakamoto <o-takashi@sakamocchi.jp>

	#include "motu.h"

	#include <linux/delay.h>

	// Status register for MOTU 828 (0x'ffff'f000'0b00).
	//
	// 0xffff0000: ISOC_COMM_CONTROL_MASK in motu-stream.c.
	// 0x00008000: mode of optical input interface.
	// 0x00008000: for S/PDIF signal.
	// 0x00000000: disabled or for ADAT signal.
	// 0x00004000: mode of optical output interface.
	// 0x00004000: for S/PDIF signal.
	// 0x00000000: disabled or for ADAT signal.
	// 0x00003f00: monitor input mode.
	// 0x00000800: analog-1/2
	// 0x00001a00: analog-3/4
	// 0x00002c00: analog-5/6
	// 0x00003e00: analog-7/8
	// 0x00000000: analog-1
	// 0x00000900: analog-2
	// 0x00001200: analog-3
	// 0x00001b00: analog-4
	// 0x00002400: analog-5
	// 0x00002d00: analog-6
	// 0x00003600: analog-7
	// 0x00003f00: analog-8
	// 0x00000080: enable stream input.
	// 0x00000040: disable monitor input.
	// 0x00000008: enable main out.
	// 0x00000004: rate of sampling clock.
	// 0x00000004: 48.0 kHz
	// 0x00000000: 44.1 kHz
	// 0x00000023: source of sampling clock.
	// 0x00000003: source packet header (SPH)
	// 0x00000002: S/PDIF on optical/coaxial interface.
	// 0x00000021: ADAT on optical interface
	// 0x00000001: ADAT on Dsub 9pin
	// 0x00000000: internal

	#define CLK_828_STATUS_OFFSET 0x0b00
	#define CLK_828_STATUS_MASK 0x0000ffff
	#define CLK_828_STATUS_FLAG_OPT_IN_IFACE_IS_SPDIF 0x00008000
	#define CLK_828_STATUS_FLAG_OPT_OUT_IFACE_IS_SPDIF 0x00004000
	#define CLK_828_STATUS_FLAG_FETCH_PCM_FRAMES 0x00000080
	#define CLK_828_STATUS_FLAG_ENABLE_OUTPUT 0x00000008
	#define CLK_828_STATUS_FLAG_RATE_48000 0x00000004
	#define CLK_828_STATUS_MASK_SRC 0x00000023
	#define CLK_828_STATUS_FLAG_SRC_ADAT_ON_OPT 0x00000021
	#define CLK_828_STATUS_FLAG_SRC_SPH 0x00000003
	#define CLK_828_STATUS_FLAG_SRC_SPDIF 0x00000002
	#define CLK_828_STATUS_FLAG_SRC_ADAT_ON_DSUB 0x00000001
	#define CLK_828_STATUS_FLAG_SRC_INTERNAL 0x00000000

	// Status register for MOTU 896 (0x'ffff'f000'0b14).
	//
	// 0xf0000000: enable physical and stream input to DAC.
	// 0x80000000: disable
	// 0x40000000: disable
	// 0x20000000: enable (prior to the other bits)
	// 0x10000000: disable
	// 0x00000000: disable
	// 0x08000000: speed of word clock signal output on BNC interface.
	// 0x00000000: force to low rate (44.1/48.0 kHz).
	// 0x08000000: follow to system clock.
	// 0x04000000: something relevant to clock.
	// 0x03000000: enable output.
	// 0x02000000: enabled irreversibly once standing unless the device voluntarily disables it.
	// 0x01000000: enabled irreversibly once standing unless the device voluntarily disables it.
	// 0x00ffff00: monitor input mode.
	// 0x00000000: disabled
	// 0x00004800: analog-1/2
	// 0x00005a00: analog-3/4
	// 0x00006c00: analog-5/6
	// 0x00007e00: analog-7/8
	// 0x00104800: AES/EBU-1/2
	// 0x00004000: analog-1
	// 0x00004900: analog-2
	// 0x00005200: analog-3
	// 0x00005b00: analog-4
	// 0x00006400: analog-5
	// 0x00006d00: analog-6
	// 0x00007600: analog-7
	// 0x00007f00: analog-8
	// 0x00104000: AES/EBU-1
	// 0x00104900: AES/EBU-2
	// 0x00000060: sample rate conversion for AES/EBU input/output.
	// 0x00000000: None
	// 0x00000020: input signal is converted to system rate
	// 0x00000040: output is slave to input, ignoring system rate
	// 0x00000060: output is double rate than system rate
	// 0x00000018: nominal rate of sampling clock.
	// 0x00000000: 44.1 kHz
	// 0x00000008: 48.0 kHz
	// 0x00000010: 88.2 kHz
	// 0x00000018: 96.0 kHz
	// 0x00000007: source of sampling clock.
	// 0x00000000: internal
	// 0x00000001: ADAT on optical interface
	// 0x00000002: AES/EBU on XLR
	// 0x00000003: source packet header (SPH)
	// 0x00000004: word clock on BNC
	// 0x00000005: ADAT on Dsub 9pin

	#define CLK_896_STATUS_OFFSET 0x0b14
	#define CLK_896_STATUS_FLAG_FETCH_ENABLE 0x20000000
	#define CLK_896_STATUS_FLAG_OUTPUT_ON 0x03000000
	#define CLK_896_STATUS_MASK_SRC 0x00000007
	#define CLK_896_STATUS_FLAG_SRC_INTERNAL 0x00000000
	#define CLK_896_STATUS_FLAG_SRC_ADAT_ON_OPT 0x00000001
	#define CLK_896_STATUS_FLAG_SRC_AESEBU 0x00000002
	#define CLK_896_STATUS_FLAG_SRC_SPH 0x00000003
	#define CLK_896_STATUS_FLAG_SRC_WORD 0x00000004
	#define CLK_896_STATUS_FLAG_SRC_ADAT_ON_DSUB 0x00000005
	#define CLK_896_STATUS_MASK_RATE 0x00000018
	#define CLK_896_STATUS_FLAG_RATE_44100 0x00000000
	#define CLK_896_STATUS_FLAG_RATE_48000 0x00000008
	#define CLK_896_STATUS_FLAG_RATE_88200 0x00000010
	#define CLK_896_STATUS_FLAG_RATE_96000 0x00000018

	static void parse_clock_rate_828(u32 data, unsigned int *rate)
	{
	if (data & CLK_828_STATUS_FLAG_RATE_48000)
	*rate = 48000;
	else
	*rate = 44100;
	}

	static int get_clock_rate_828(struct snd_motu motu, unsigned int rate)
	{
	__be32 reg;
	int err;

	err = snd_motu_transaction_read(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
	if (err < 0)
	return err;
	parse_clock_rate_828(be32_to_cpu(reg), rate);

	return 0;
	}

	static int parse_clock_rate_896(u32 data, unsigned int *rate)
	{
	switch (data & CLK_896_STATUS_MASK_RATE) {
	case CLK_896_STATUS_FLAG_RATE_44100:
	*rate = 44100;
	break;
	case CLK_896_STATUS_FLAG_RATE_48000:
	*rate = 48000;
	break;
	case CLK_896_STATUS_FLAG_RATE_88200:
	*rate = 88200;
	break;
	case CLK_896_STATUS_FLAG_RATE_96000:
	*rate = 96000;
	break;
	default:
	return -ENXIO;
	}

	return 0;
	}

	static int get_clock_rate_896(struct snd_motu motu, unsigned int rate)
	{
	__be32 reg;
	int err;

	err = snd_motu_transaction_read(motu, CLK_896_STATUS_OFFSET, &reg, sizeof(reg));
	if (err < 0)
	return err;
	return parse_clock_rate_896(be32_to_cpu(reg), rate);
	}

	int snd_motu_protocol_v1_get_clock_rate(struct snd_motu motu, unsigned int rate)
	{
	if (motu->spec == &snd_motu_spec_828)
	return get_clock_rate_828(motu, rate);
	else if (motu->spec == &snd_motu_spec_896)
	return get_clock_rate_896(motu, rate);
	else
	return -ENXIO;
	}

	static int set_clock_rate_828(struct snd_motu *motu, unsigned int rate)
	{
	__be32 reg;
	u32 data;
	int err;

	err = snd_motu_transaction_read(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
	if (err < 0)
	return err;
	data = be32_to_cpu(reg) & CLK_828_STATUS_MASK;

	data &= ~CLK_828_STATUS_FLAG_RATE_48000;
	if (rate == 48000)
	data \|= CLK_828_STATUS_FLAG_RATE_48000;

	reg = cpu_to_be32(data);
	return snd_motu_transaction_write(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
	}

	static int set_clock_rate_896(struct snd_motu *motu, unsigned int rate)
	{
	unsigned int flag;
	__be32 reg;
	u32 data;
	int err;

	err = snd_motu_transaction_read(motu, CLK_896_STATUS_OFFSET, &reg, sizeof(reg));
	if (err < 0)
	return err;
	data = be32_to_cpu(reg);

	switch (rate) {
	case 44100:
	flag = CLK_896_STATUS_FLAG_RATE_44100;
	break;
	case 48000:
	flag = CLK_896_STATUS_FLAG_RATE_48000;
	break;
	case 88200:
	flag = CLK_896_STATUS_FLAG_RATE_88200;
	break;
	case 96000:
	flag = CLK_896_STATUS_FLAG_RATE_96000;
	break;
	default:
	return -EINVAL;
	}

	data &= ~CLK_896_STATUS_MASK_RATE;
	data \|= flag;

	reg = cpu_to_be32(data);
	return snd_motu_transaction_write(motu, CLK_896_STATUS_OFFSET, &reg, sizeof(reg));
	}

	int snd_motu_protocol_v1_set_clock_rate(struct snd_motu *motu, unsigned int rate)
	{
	if (motu->spec == &snd_motu_spec_828)
	return set_clock_rate_828(motu, rate);
	else if (motu->spec == &snd_motu_spec_896)
	return set_clock_rate_896(motu, rate);
	else
	return -ENXIO;
	}

	static int get_clock_source_828(struct snd_motu motu, enum snd_motu_clock_source src)
	{
	__be32 reg;
	u32 data;
	int err;

	err = snd_motu_transaction_read(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
	if (err < 0)
	return err;
	data = be32_to_cpu(reg) & CLK_828_STATUS_MASK;

	switch (data & CLK_828_STATUS_MASK_SRC) {
	case CLK_828_STATUS_FLAG_SRC_ADAT_ON_OPT:
	*src = SND_MOTU_CLOCK_SOURCE_ADAT_ON_OPT;
	break;
	case CLK_828_STATUS_FLAG_SRC_SPH:
	*src = SND_MOTU_CLOCK_SOURCE_SPH;
	break;
	case CLK_828_STATUS_FLAG_SRC_SPDIF:
	{
	if (data & CLK_828_STATUS_FLAG_OPT_IN_IFACE_IS_SPDIF)
	*src = SND_MOTU_CLOCK_SOURCE_SPDIF_ON_COAX;
	else
	*src = SND_MOTU_CLOCK_SOURCE_SPDIF_ON_OPT;
	break;
	}
	case CLK_828_STATUS_FLAG_SRC_ADAT_ON_DSUB:
	*src = SND_MOTU_CLOCK_SOURCE_ADAT_ON_DSUB;
	break;
	case CLK_828_STATUS_FLAG_SRC_INTERNAL:
	*src = SND_MOTU_CLOCK_SOURCE_INTERNAL;
	break;
	default:
	return -ENXIO;
	}

	return 0;
	}

	static int get_clock_source_896(struct snd_motu motu, enum snd_motu_clock_source src)
	{
	__be32 reg;
	u32 data;
	int err;

	err = snd_motu_transaction_read(motu, CLK_896_STATUS_OFFSET, &reg, sizeof(reg));
	if (err < 0)
	return err;
	data = be32_to_cpu(reg);

	switch (data & CLK_896_STATUS_MASK_SRC) {
	case CLK_896_STATUS_FLAG_SRC_INTERNAL:
	*src = SND_MOTU_CLOCK_SOURCE_INTERNAL;
	break;
	case CLK_896_STATUS_FLAG_SRC_ADAT_ON_OPT:
	*src = SND_MOTU_CLOCK_SOURCE_ADAT_ON_OPT;
	break;
	case CLK_896_STATUS_FLAG_SRC_AESEBU:
	*src = SND_MOTU_CLOCK_SOURCE_AESEBU_ON_XLR;
	break;
	case CLK_896_STATUS_FLAG_SRC_SPH:
	*src = SND_MOTU_CLOCK_SOURCE_SPH;
	break;
	case CLK_896_STATUS_FLAG_SRC_WORD:
	*src = SND_MOTU_CLOCK_SOURCE_WORD_ON_BNC;
	break;
	case CLK_896_STATUS_FLAG_SRC_ADAT_ON_DSUB:
	*src = SND_MOTU_CLOCK_SOURCE_ADAT_ON_DSUB;
	break;
	default:
	return -ENXIO;
	}

	return 0;
	}

	int snd_motu_protocol_v1_get_clock_source(struct snd_motu motu, enum snd_motu_clock_source src)
	{
	if (motu->spec == &snd_motu_spec_828)
	return get_clock_source_828(motu, src);
	else if (motu->spec == &snd_motu_spec_896)
	return get_clock_source_896(motu, src);
	else
	return -ENXIO;
	}

	static int switch_fetching_mode_828(struct snd_motu *motu, bool enable)
	{
	__be32 reg;
	u32 data;
	int err;

	err = snd_motu_transaction_read(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
	if (err < 0)
	return err;
	data = be32_to_cpu(reg) & CLK_828_STATUS_MASK;

	data &= ~(CLK_828_STATUS_FLAG_FETCH_PCM_FRAMES \| CLK_828_STATUS_FLAG_ENABLE_OUTPUT);
	if (enable) {
	// This transaction should be initiated after the device receives batch of packets
	// since the device voluntarily mutes outputs. As a workaround, yield processor over
	// 100 msec.
	msleep(100);
	data \|= CLK_828_STATUS_FLAG_FETCH_PCM_FRAMES \| CLK_828_STATUS_FLAG_ENABLE_OUTPUT;
	}

	reg = cpu_to_be32(data);
	return snd_motu_transaction_write(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
	}

	static int switch_fetching_mode_896(struct snd_motu *motu, bool enable)
	{
	__be32 reg;
	u32 data;
	int err;

	err = snd_motu_transaction_read(motu, CLK_896_STATUS_OFFSET, &reg, sizeof(reg));
	if (err < 0)
	return err;
	data = be32_to_cpu(reg);

	data &= ~CLK_896_STATUS_FLAG_FETCH_ENABLE;
	if (enable)
	data \|= CLK_896_STATUS_FLAG_FETCH_ENABLE \| CLK_896_STATUS_FLAG_OUTPUT_ON;

	reg = cpu_to_be32(data);
	return snd_motu_transaction_write(motu, CLK_896_STATUS_OFFSET, &reg, sizeof(reg));
	}

	int snd_motu_protocol_v1_switch_fetching_mode(struct snd_motu *motu, bool enable)
	{
	if (motu->spec == &snd_motu_spec_828)
	return switch_fetching_mode_828(motu, enable);
	else if (motu->spec == &snd_motu_spec_896)
	return switch_fetching_mode_896(motu, enable);
	else
	return -ENXIO;
	}

	static int detect_packet_formats_828(struct snd_motu *motu)
	{
	__be32 reg;
	u32 data;
	int err;

	motu->tx_packet_formats.pcm_byte_offset = 4;
	motu->tx_packet_formats.msg_chunks = 2;

	motu->rx_packet_formats.pcm_byte_offset = 4;
	motu->rx_packet_formats.msg_chunks = 0;

	err = snd_motu_transaction_read(motu, CLK_828_STATUS_OFFSET, &reg, sizeof(reg));
	if (err < 0)
	return err;
	data = be32_to_cpu(reg) & CLK_828_STATUS_MASK;

	// The number of chunks is just reduced when SPDIF is activated.
	if (!(data & CLK_828_STATUS_FLAG_OPT_IN_IFACE_IS_SPDIF))
	motu->tx_packet_formats.pcm_chunks[0] += 8;

	if (!(data & CLK_828_STATUS_FLAG_OPT_OUT_IFACE_IS_SPDIF))
	motu->rx_packet_formats.pcm_chunks[0] += 8;

	return 0;
	}

	static int detect_packet_formats_896(struct snd_motu *motu)
	{
	// 24bit PCM frames follow to source packet header without message chunk.
	motu->tx_packet_formats.pcm_byte_offset = 4;
	motu->rx_packet_formats.pcm_byte_offset = 4;

	// No message chunk in data block.
	motu->tx_packet_formats.msg_chunks = 0;
	motu->rx_packet_formats.msg_chunks = 0;

	// Always enable optical interface for ADAT signal since the device have no registers
	// to refer to current configuration.
	motu->tx_packet_formats.pcm_chunks[0] += 8;
	motu->tx_packet_formats.pcm_chunks[1] += 8;

	motu->rx_packet_formats.pcm_chunks[0] += 8;
	motu->rx_packet_formats.pcm_chunks[1] += 8;

	return 0;
	}

	int snd_motu_protocol_v1_cache_packet_formats(struct snd_motu *motu)
	{
	memcpy(motu->tx_packet_formats.pcm_chunks, motu->spec->tx_fixed_pcm_chunks,
	sizeof(motu->tx_packet_formats.pcm_chunks));
	memcpy(motu->rx_packet_formats.pcm_chunks, motu->spec->rx_fixed_pcm_chunks,
	sizeof(motu->rx_packet_formats.pcm_chunks));

	if (motu->spec == &snd_motu_spec_828)
	return detect_packet_formats_828(motu);
	else if (motu->spec == &snd_motu_spec_896)
	return detect_packet_formats_896(motu);
	else
	return 0;
	}

	const struct snd_motu_spec snd_motu_spec_828 = {
	.name = "828",
	.protocol_version = SND_MOTU_PROTOCOL_V1,
	.tx_fixed_pcm_chunks = {10, 0, 0},
	.rx_fixed_pcm_chunks = {10, 0, 0},
	};

	const struct snd_motu_spec snd_motu_spec_896 = {
	.name = "896",
	.tx_fixed_pcm_chunks = {10, 10, 0},
	.rx_fixed_pcm_chunks = {10, 10, 0},
	};