ALSA: firewire: use 'GPL' string for module license contributed by Clemens Ladisch

In MODULE_LICENSE macro, "GPL" string obsoletes "GPL v2" string by a
commit bf7fbeeae6db ("module: Cure the MODULE_LICENSE "GPL" vs. "GPL v2"
bogosity").

This commit uses the preferable expression.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20230611144445.221529-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-lib: delete unused kernel API

No driver use snd_fw_schedule_registration(). Let's delete it.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210607081250.13397-10-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/firewire-tascam: localize async midi port

In Linux kernel 4.4, firewire-lib got a feature called as 'async midi port'
for transmission of MIDI message via IEEE 1394 asynchronous communication,
however actual consumer of this feature is ALSA driver for TASCAM FireWire
series only. When adding this feature, I assumed that ALSA driver for
Digi00x might also be a consumer, actually it's not.

This commit moves the feature from firewire-lib to firewire-tascam module.
Two minor kernel APIs are removed.

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

ktime: Cleanup ktime_set() usage

ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>

ALSA: firewire-lib: add new function to schedule a work for sound card registration

In former commit, ALSA dice driver postpone sound card registration after
IEEE 1394 bus is calm. This idea has advantages for the other drivers.

This commit adds a helper function for it to firewire-lib module. The
function is really for the specific purpose. Callers should initialize
delayed work structure with callback function.

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

ALSA: firewire-lib: avoid NULL pointer dereference after closing MIDI port

When asynchronous MIDI port is closed before callbacked, the callback
function causes NULL pointer dereference to missing MIDI substream.

This commit fixes this bug.

Fixes: e8a40d9bcb23('ALSA: firewire-lib: schedule work again when MIDI substream has rest of MIDI messages')
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: firewire-lib: avoid endless loop to transfer MIDI messages at fatal error

Currently, when asynchronous transactions finish in error state and
retries, work scheduling and work running also continues. This
should be canceled at fatal error because it can cause endless loop.

This commit enables to cancel transferring MIDI messages when transactions
encounter fatal errors. This is achieved by setting error state.

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

ALSA: firewire-lib: add throttle for MIDI data rate

Typically, the target devices have internal buffer to adjust output of
received MIDI messages for MIDI serial bus, while the capacity of the
buffer is limited. IEEE 1394 transactions can transfer more MIDI messages
than MIDI serial bus can. This can cause buffer over flow in device side.

This commit adds throttle to limit MIDI data rate by counting intervals
between two MIDI messages. Usual MIDI messages consists of two or three
bytes. This requires 1.302 to 1.953 mili-seconds interval between these
messages. This commit uses kernel monotonic time service to calculate the
time of next transaction.

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

ALSA: firewire-lib: schedule work again when MIDI substream has rest of MIDI messages

Currently, when two MIDI trigger callbacks can be called immediately,
transactions for the second MIDI messages can be postpone till next trigger
callback. This is not good for real-time message transmission.

This commit schedules work again at response handling callback if the
MIDI substream still includes untransferred MIDI messages.

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

ALSA: firewire-lib: add a restriction for a transaction at once

Currently, when waiting for a response, callers can start another
transaction by scheduling another work. This is not good for error
processing of transaction, especially the first response is too late.

This commit serialize request/response transactions, by adding one
boolean member to represent idling state.

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

ALSA: firewire-lib: add helper functions for asynchronous transactions to transfer MIDI messages

Some models receive MIDI messages via IEEE 1394 asynchronous transactions.
In this case, MIDI messages are transferred in fixed-length payload. It's
nice that firewire-lib module has common helper functions.

This commit implements this idea. Each driver adds
'struct snd_fw_async_midi_port' in its instance structure. In probing,
it should call snd_fw_async_midi_port_init() to initialize the
structure with some parameters such as target address, the length
of payload in a transaction and a pointer for callback function
to fill the payload buffer. At 'struct snd_rawmidi_ops.trigger()'
callback, it should call 'snd_fw_async_midi_port_run()' to start
transactions. Each driver should ensure that the lifetime of MIDI
substream continues till calling 'snd_fw_async_midi_port_finish()'.

The helper functions support retries to transferring MIDI messages when
transmission errors occur. When transactions are successful, the helper
functions call 'snd_rawmidi_transmit_ack()' internally to consume MIDI
bytes in the buffer. Therefore, Each driver is expected to use
'snd_rawmidi_transmit_peek()' to tell the number of bytes to transfer to
return value of 'fill' callback.

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

ALSA: firewire: extend snd_fw_transaction()

Add a flag to snd_fw_transaction() to allow it to abort when a bus reset
happens. This removes most of the duplicated error handling loops that
were required around calls to the low-level fw_run_transaction().

Also add a flag to suppress error messages; errors are expected when we
attempt to clean up after the device was unplugged.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

firewire: move rcode_string() to core

There is nothing audio-specific about the rcode_string() helper, so move
it from snd-firewire-lib into firewire-core to allow other code to use it.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (fixed sound/firewire/cmp.c)

ALSA: add LaCie FireWire Speakers/Griffin FireWave Surround driver

Add a driver for two playback-only FireWire devices based on the OXFW970
chip.

v2: better AMDTP API abstraction; fix fw_unit leak; small fixes
v3: cache the iPCR value
v4: FireWave constraints; fix fw_device reference counting;
fix PCR caching; small changes and fixes
v5: volume/mute support; fix crashing due to pcm stop races
v6: fix build; one-channel volume for LaCie
v7: use signed values to make volume (range checks) work; fix function
block IDs for volume/mute; always use channel 0 for LaCie volume

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tested-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>