ALSA: firewire-lib: obsolete return value from context payload processing layer

This commit obsoletes return value from the context payload processing layer
since the multiplier between the data block count and PCM frame count was
moved to the packet streaming processing layer.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20230110134933.322794-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-lib: move parameter for pcm frame multiplier from context payload processing layer

The current implementation delegates the task to calculate the number of
processed PCM frames into the context payload processing layer. It looks
good as long as frame calculation is done for a single purpose.
Nevertheless, another purpose, the computation of extra delay for the
runtime of PCM substream, requires frame calculation, too.

This commit refactors the current implementation so that the packet stream
processing layer is responsible for the calculation of PCM frame, too. The
member is moved to stream structure for multiplier between data block
count and PCM frame count.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20230110134933.322794-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-lib: use circular linked list for context payload processing layer

The list of packet descriptor is passed to context payload processing
layer so that each driver can copy PCM frames, MIDI messages, and device
specific data between packet payload buffer and intermediate buffer for
user space application.

The list of packet descriptor was replaced by circular linked list in a
previous commit. This commit uses circular linked in context payload
processing layer as well.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20230109021738.75543-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: remove TODO for interaction with userspace about control message

Now UAPI of ALSA firewire stack got enough functions to interact with
userspace for protocol of MOTU FireWire series. Let's remove the relevant
TODO.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20211029012847.11839-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: add message parser for meter information in command DSP model

Some of MOTU models allows software to configure their DSP parameters by
command included in asynchronous transaction. The models multiplex messages
for hardware meters into isochronous packet as well as PCM frames. For
convenience, I call them as 'command DSP' model.

This patch adds message parser for them to gather hardware meter
information.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20211015080826.34847-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: add message parser to gather meter information in register DSP model

Some of MOTU models allows software to configure their DSP parameters by
accessing to their registers. The models multiplex messages for status of
DSP into isochronous packet as well as PCM frames. The message includes
information of hardware metering, MIDI message, current parameters of DSP.
For my convenience, I call them as 'register DSP' model.

This patch adds message parser for them to gather hardware meter
information.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20211015080826.34847-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: fix truncated bytes in message tracepoints

In MOTU protocol v2/v3, first two data chunks across 2nd and 3rd data
channels includes message bytes from device. The total size of message
is 48 bits per data block.

The 'data_block_message' tracepoints event produced by ALSA firewire-motu
driver exposes the sequence of messages to userspace in 64 bit storage,
however lower 32 bits are actually available since current implementation
truncates 16 bits in upper of the message as a result of bit shift
operation within 32 bit storage.

This commit fixes the bug by perform the bit shift in 64 bit storage.

Fixes: c6b0b9e65f09 ("ALSA: firewire-motu: add tracepoints for messages for unique protocol")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210920110734.27161-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: sequence replay for source packet header

This commit takes ALSA firewire-motu driver to perform sequence replay for
media clock recovery.

Unlike the other types of device, the devices in MOTU FireWire series
require two levels of sequence replay; the sequence of the number of
data blocks per packet and the sequence of source packet header per data
block. The former is already cached by ALSA IEC 61883-1/6 packet streaming
engine and ready to be replayed. The latter is also cached by ALSA
firewire-motu driver itself with a previous patch. This commit takes
the driver to replay both of them from the caches.

The sequence replay is tested with below models:

* 828 mkII
* Traveler
* UltraLite
* 828 mk3 FireWire
* 828 mk3 Hybrid (except for high sampling transfer frequency
* UltraLite mk3 FireWire
* 4pre
* AudioExpress

Unfortunately, below models still don't generate better sound, requires
more work:

* 8pre
* 828 mk3 Hybrid at high sampling transfer frequency

As long as I know, MOTU protocol version 1 requires extra care of the
format of data block, thus below models are not supported yet in this
time:

* 828
* 896

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210602013406.26442-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: cache event ticks in source packet header per data block

The devices in MOTU FireWire series put source packet header (SPH) into
each data block of tx packet for presentation time of event. The format
of timestamp is compliant to IEC 61883-1, with cycle and offset fields
without sec field of 32 bit cycle time.

This commit takes ALSA firewire-motu driver to cache the presentation
time as offset from cycle in which the packet is transferred.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210602013406.26442-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: use macro for magic numbers relevant to IEC 61883-1

ALSA firewire-motu driver has some magic numbers from IEC 61883-1 to
operates source packet header (SPH). This commit replaces them with
macros.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210602013406.26442-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-lib: add flag to unaware of syt in CIP header

Many devices are unaware of syt field in rx CIP for playback timing.

This commit adds a flag to cancel processing syt field. Actually,
syt calculation is required to decide the number of events per rx packet.
The flag put 0xffff to CIP header of rx packet. On the other hand,
The value of syt field in CIP header of tx packet is unavailable. The
sequence of packet descriptor for tx packet includes 0 for the offset
of syt field to avoid computation.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210522013303.49596-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-lib: start processing content of packet at the same cycle in several IT contexts

DICE ASICs support several pairs of isochronous packet streaming and
expect software to queue packets with the same timing information into
the same isochronous cycle.

This commit adds structure member to manage the cycle to start
processing packet in several IT contexts. The cycle is decided when
batch of isochronous cycle is skipped in callback to isochronous context
for IRQ target.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210520040154.80450-8-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: use table-based calculation of packet formats for stream management

This commit uses table-based calculation of packet formats for stream
management.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20200519111641.123211-11-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: localize protocol data

This commit adds enumerations of protocol version to localize protocol
data.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20200519111641.123211-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: more code refactoring for MOTU data block processing layer

MOTU data block processing layer has some tracepoints events. This
commit is code refactoring to split probing the events from processing
data blocks.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-lib: process payload of isoc context according to packet descriptors

This commit changes each of data block processing layer so that it
receives list of packet descriptor.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: code refactoring for MOTU data block processing layer

This is code refactoring for MOTU data block processing layer so that
it can receive list of packet descriptor.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-lib: pass packet descriptor to data block processing layer

This commit changes signature of callback function to call data block
processing layer with packet descriptor. At present, the layer is called
per packet.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-lib: pass no syt information to data block processing layer

In a previous commit, the variable passed from packet streaming layer
for syt variable is useless. This commit obsoletes it.

In my future work, the syt information is passed to data block processing
layer by another way.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-lib: add syt_override member for some protocols

Some protocols don't use syt field of CIP header to represent
presentation timestamp. For such protocol, ALSA IEC 61883-1/6
packet streaming engine uses a pointer into local variable for
the value of syt to call data block processing layer. However,
it can decide the value when initializing packet streaming
layer.

This commit adds 'syt_override' member for packet streaming
layer.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-lib: pass data block counter to data block processing layer

This is a preparation for future commit that 'struct
amdtp_stream.data_block_count' does not represent the value of
data block count for current data block.

However, data block count is required for calculation of sequence index
in sequence-multiplied data channel. Some of data block processing layer
require it; e.g. for AM824 data block.

This commit passes data block count to the processing layer.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: unify common tracepoints for both direction

In ALSA firewire-motu driver, some tracepoints are supported to probe
vendor-specific data fields for SPH and status/control messages in
payload of isochronous packet. At present, the events of tracepoints
are unique each of direction, however the pair of events has the
same structure and print format. It's possible to unify the pair.

This commit unifies the pair. From userspace, direction is specified
by filtering for src/dst fields in the structure.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 345

Based on 1 normalized pattern(s):

licensed under the terms of the gnu general public license version 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 88 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000437.521539229@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ALSA: firewire-lib: use union for directional parameters

Some parameters of struct amdtp_stream is dependent on direction.

This commit uses union for such parameters to distinguish from
common parameters.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: add support MOTU 8pre FireWire

This commit adds support for MOTU 8pre FireWire, which was shipped 2007
and nowadays already discontinued. Userspace applications can transmit
and receive PCM frames and MIDI messages for this model via ALSA PCM
interface and RawMidi/Sequencer interfaces.

Like the other models of MOTU FireWire series, this model has many
quirks in its CIP.

At first, data channels for two pairs of optical interfaces. At lower
sampling transmission frequency, i.e. 44.1 and 48.0 kHz, one pair is
available for ADAT data, thus 8 data chunks are transferred by CIP.
At middle sampling transmission frequency, i.e. 88.2 and 96.0 kHz,
two pairs are available to keep 8 chunks for ADAT data, thus CIP
still includes 8 data chunks.

Apart from data chunks for optical interface, CIP includes fixed number
of data chunks. In tx stream, two chunks for status message, eight
chunks for samples from analog 1-8 input, two chunks for mix-return.
In rx stream, two chunks for control message, two chunks for main 1-2
output, two chunks for phone 1-2 output, two chunks for dummy 1-2.

CIP header in tx stream includes quirks for its dbs and dbc fields.
The value of dbs field is fixed to 0x13, against its actual size.
The value of dbc field is firstly updated to 0x07 from zero, then
it's incremented continuously according to actual number of data h
blocks.

Finally, the model has own bits to disable frame fetch.

This commit uses several options to absorb the above quirks.

$ python2 crpp < /sys/bus/firewire/devices/fw1/config_rom
ROM header and bus information block
-----------------------------------------------------------------
400 0410b57d bus_info_length 4, crc_length 16, crc 46461
404 31333934 bus_name "1394"
408 20001000 irmc 0, cmc 0, isc 1, bmc 0, cyc_clk_acc 0, max_rec 1 (4)
40c 0001f200 company_id 0001f2 |
410 00083dfb device_id 0000083dfb | EUI-64 0001f20000083dfb

root directory
-----------------------------------------------------------------
414 0004c65c directory_length 4, crc 50780
418 030001f2 vendor
41c 0c0083c0 node capabilities per IEEE 1394
420 8d000006 --> eui-64 leaf at 438
424 d1000001 --> unit directory at 428

unit directory at 428
-----------------------------------------------------------------
428 0003991c directory_length 3, crc 39196
42c 120001f2 specifier id
430 1300000f version
434 17103800 model

eui-64 leaf at 438
-----------------------------------------------------------------
438 00022681 leaf_length 2, crc 9857
43c 0001f200 company_id 0001f2 |
440 00083dfb device_id 0000083dfb | EUI-64 0001f20000083dfb

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: fix construction of PCM frame for capture direction

In data blocks of common isochronous packet for MOTU devices, PCM
frames are multiplexed in a shape of '24 bit * 4 Audio Pack', described
in IEC 61883-6. The frames are not aligned to quadlet.

For capture PCM substream, ALSA firewire-motu driver constructs PCM
frames by reading data blocks byte-by-byte. However this operation
includes bug for lower byte of the PCM sample. This brings invalid
content of the PCM samples.

This commit fixes the bug.

Reported-by: Peter Sjöberg <autopeter@gmail.com>
Cc: <stable@vger.kernel.org> # v4.12+
Fixes: 4641c9394010 ("ALSA: firewire-motu: add MOTU specific protocol layer")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE()

Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.

For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.

However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:

----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()

// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch

virtual patch

@ depends on patch @
expression E1, E2;
@@

- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)

@ depends on patch @
expression E;
@@

- ACCESS_ONCE(E)
+ READ_ONCE(E)
----

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

ALSA: firewire-motu: mark trace helpers as __maybe_unused

Two functions were introduced for the purpose of tracing but cause warnings
when tracing is disabled:

sound/firewire/motu/amdtp-motu.c:284:13: error: 'copy_message' defined but not used [-Werror=unused-function]
static void copy_message(u64 *frames, __be32 *buffer, unsigned int data_blocks,
sound/firewire/motu/amdtp-motu.c:271:13: error: 'copy_sph' defined but not used [-Werror=unused-function]
static void copy_sph(u32 *frames, __be32 *buffer, unsigned int data_blocks,

Marking them as __maybe_unused will do the right thing here.

Fixes: 17909c1b3058 ("ALSA: firewire-motu: add tracepoints for SPH in IEC 61883-1 fashion")
Fixes: c6b0b9e65f09 ("ALSA: firewire-motu: add tracepoints for messages for unique protocol")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: add tracepoints for messages for unique protocol

MOTU units transfer/receive messages in each data block of their
isochronous packet payload. A part of content in the message is cleard for
MIDI message transmission, while the rest is unknown yet. Additional
features are required to assist users and developers to reveal the
details.

This commit adds tracepoints for the purpose. The tracepoints are designed
for MOTU's protocol version 2 and 3 (Protocol version 1 is not upstreamed
yet). In the tracepoints, events are probed to gather first two 24 bit
data chunks of each data block. The chunks are formatted into elements
of 64 bit array with padding in MSB.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: add tracepoints for SPH in IEC 61883-1 fashion

Unique protocol is used for MOTU FireWire series. In this protocol,
data block format is not compliant to AM824 in IEC 61883-1/6. Each of
the data block consists of 24 bit data chunks, except for a first
quadlet. The quadlet is used for source packet header (SPH) described
in IEC 61883-1.

The sequence of SPH seems to represent presentation timestamp
corresponding to included data. Developers have experienced that invalid
sequence brings disorder of units in the series.

Unfortunately, current implementation of ALSA IEC 61883-1/6 engine and
firewire-motu driver brings periodical noises to the units at sampling
transmission frequency based on 44.1 kHz. The engine generates the SPH with
even interval and this mechanism seems not to be suitable to the units.
Further work is required for this issue and infrastructure is preferable
to assist the work.

This commit adds tracepoints for the purpose. In the tracepoints, events
are probed to gather the SPHs from each data blocks.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: add support for MOTU 828mk3 (FireWire/Hybrid) as a model with protocol version 3

MOTU 828mk3 (FireWire/Hybrid) is one of third generation in MOTU FireWire
series, produced in 2008/2014. This model consists of three chips for
functionality on IEEE 1394 bus:

* TI TSB41AB2 (Physical layer for IEEE 1394 bus)
* Xilinx Spartan-3E FPGA Family (Link layer for IEEE 1394 bus, packet
processing and data block processing layer)
* TI TMS320C6722 (Digital signal processing)

This commit adds a support for this model, with its unique protocol as
version 3. This protocol has some additional features to protocol
version 2.

* Support several optical interfaces.
* Support a data chunk for return of reverb effect.
* Have a quirk of tx packets.
* Support heartbeat asynchronous transaction.

In this protocol, series of transferred packets has some quirks. Below
fields in CIP headers of the packets are out of IEC 61883-1:
- SID (source node id): always 0x0d
- DBS (data block size): always 0x04
- DBC (data block counter): always 0x00
- EOH (End of header): always 0x00

Below is an actual sample of transferred packets.

quads CIP1 CIP2
520 0x0D040400 0x22FFFFFF
8 0x0D040400 0x22FFFFFF
520 0x0D040400 0x22FFFFFF
520 0x0D040400 0x22FFFFFF
8 0x0D040400 0x22FFFFFF

Status of clock is configured by write transactions to 0x'ffff'f000'0b14,
as well as version 2, while meanings of fields are different from the
former protocols. Modes of optical interfaces are configured by write
transactions to 0x'ffff'f000'0c94.

Drivers can register its address to receive heatbeat transactions from the
unit. 0x'ffff'f000'0b0c is for the higher part and 0x'ffff'f000'0b10 is
for the lower part. Nevertheless, this feature is not useless for this
driver and this commit omits it.

Each data block consists of two parts in a point of the number of included
data chunks. In both of 'fixed' and 'differed' parts, the number of
included data blocks are a multiple of 4, thus depending on models there's
some empty data chunks. For example, 828mk3 includes one pair of empty
data chunks in its fixed part. When optical interface is configured to
S/PDIF, 828mk3 includes one pair of empty data chunks in its differed part.
To reduce consumption of CPU cycles with additional conditions/loops, this
commit just exposes these empty chunks to user space as PCM channels.

Additionally, 828mk3 has a non-negligible overhead to change its sampling
transfer frequency. When softwares send asynchronous transaction to
perform it, LED on the unit starts to blink. In a worst case, it continues
blink during several seconds; e.g. 10 seconds. When stopping blinking,
the unit seems to be prepared for the requested sampling transfer
frequency. To wait for the preparation, this commit forces the driver
to call task scheduler and applications sleeps for 4 seconds.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: add MIDI functionality

In MOTU FireWire series, MIDI messages are multiplexed to isochronous
packets as well as PCM frames, while the way is different from the one
in IEC 61883-6.

MIDI messages are put into a certain position in message chunks. One data
block can includes one byte of the MIDI messages. When data block includes
a MIDI byte, the block has a flag in a certain position of the message
chunk. These positions are unique depending on protocols.

Once a data block includes a MIDI byte, some following data blocks includes
no MIDI bytes. Next MIDI byte appears on a data block corresponding to
next cycle of physical MIDI bus. This seems to avoid buffer overflow caused
by bandwidth differences between IEEE 1394 bus and physical MIDI bus.

This commit adds MIDI functionality to transfer/receive MIDI messages.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-motu: add MOTU specific protocol layer

MOTU FireWire series uses blocking transmission for AMDTP packet streaming.
They transmit/receive 8,000 packets per second, to handle the same number
of data blocks as current sampling transmission frequency. Thus,
IEC 61883-1/6 packet streaming engine of ALSA firewire stack is available
for them.

However, the sequence of packet and data blocks includes some quirks.
Below sample is a sequence of CIP headers of packets received by 828mk2,
at 44.1kHz of sampling transmission frequency.

quads CIP1 CIP2
488 0x020F04E8 0x8222FFFF
8 0x020F04F8 0x8222FFFF
488 0x020F0400 0x8222FFFF
488 0x020F0408 0x8222FFFF
8 0x020F04E8 0x8222FFFF
488 0x020F04F0 0x8222FFFF
488 0x020F04F8 0x8222FFFF

The SID (source node ID), DBS (data block size), SPH (source packet header),
FMT (format ID), FDF (format dependent field) and SYT (time stamp) fields
are in IEC 61883-1. Especially, FMT is 0x02, FDF is 0x22 and SYT is 0xffff
to define MOTU specific protocol. In an aspect of dbc field, the value
represents accumulated number of data blocks included the packet. This
is against IEC 61883-1, because according to the specification this value
should be the number of data blocks already transferred.

In ALSA IEC 61883-1/6 engine, this quirk is already supported by
CIP_DBC_IS_END_EVENT flag, because Echo Audio Fireworks has.

Each data block includes SPH as its first quadlet field, to represent its
presentation time stamp. Actual value of SPH is compliant to IEC 61883-1;
lower 25 bits of 32 bits width consists of 13 bits cycle count and 12 bits
cycle offset.

The rest of each data block consists of 24 bit chunks. All of PCM samples,
MIDI messages, status and control messages are transferred by the chunks.
This is similar to '24-bit * 4 Audio Pack' in IEC 61883-6. The position of
each kind of data depends on generations of each model. The number of
whole chunks in a data block is a multiple of 4, to consists of
quadlet-aligned packets.

This commit adds data block processing layer specific for the MOTU
protocol. The remarkable point is the way to generate SPH header. Time
stamps for each data blocks are generated by below calculation:

* Using pre-computed table for the number of ticks per event
* 44,1kHz: (557 + 123/441)
* 48.0kHz: (512 + 0/441)
* 88.2kHz: (278 + 282/441)
* 96.0kHz: (256 + 0/441)
* 176.4kHz: (139 + 141/441)
* 192.0kHz: (128 + 0/441)
* Accumulate the ticks and set the value to SPH for every events.
* This way makes sense only for blocking transmission because this mode
transfers fixed number or none of events.

This calculation assumes that each data block has a PCM frame which is
sampled according to event timing clock. Current packet streaming layer
has the same assumption.

Although this sequence works fine for MOTU FireWire series at sampling
transmission frequency based on 48.0kHz, it is not enough at the frequency
based on 44.1kHz. The units generate choppy noise every few seconds.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>