Just reformatting the comments and typos fixed, no functional
changes.  Particularly,
- avoid the kerneldoc marker "/**",
- reduce multiple comment lines into single lines,
- corrected wrongly referred function names
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Both playback and capture callbacks are identical, so let's merge
them.
Tested-by: NChris Rorvick <chris@rorvick.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The current code deals with the stream start / stop solely via
line6_pcm_acquire() and line6_pcm_release().  This was (supposedly)
intended to avoid the races, but it doesn't work as expected.  The
concurrent acquire and release calls can be performed without proper
protections, thus this might result in memory corruption.
Furthermore, we can't take a mutex to protect the whole function
because it can be called from the PCM trigger callback that is an
atomic context.  Also spinlock isn't appropriate because the function
allocates with kmalloc with GFP_KERNEL.  That is, these function just
lead to singular problems.

This is an attempt to reduce the existing races.  First off, separate
both the stream buffer management and the stream URB management.  The
former is protected via a newly introduced state_mutex while the
latter is protected via each line6_pcm_stream lock.

Secondly, the stream state are now managed in opened and running bit
flags of each line6_pcm_stream.  Not only this a bit clearer than
previous combined bit flags, this also gives a better abstraction.
These rewrites allows us to make common hw_params and hw_free
callbacks for both playback and capture directions.

For the monitor and impulse operations, still line6_pcm_acquire() and
line6_pcm_release() are used.  They call internally the corresponding
functions for both playback and capture streams with proper lock or
mutex.  Unlike the previous versions, these function don't take the
bit masks but the only single type value.  Also they are supposed to
be applied only as duplex operations.
Tested-by: NChris Rorvick <chris@rorvick.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Introduce a new line6_pcm_stream structure and group individual
fields of snd_line6_pcm struct to playback and capture groups.

This patch itself just does rename and nothing else.  More
meaningful cleanups based on these fields shuffling will follow.
Tested-by: NChris Rorvick <chris@rorvick.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The trigger callback is already spinlocked, so we need no more lock
here (even for the linked substreams).  Let's drop it.
Tested-by: NChris Rorvick <chris@rorvick.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The driver version string was removed in an ealier commit for being
useless.  These are equally useless.
Signed-off-by: NChris Rorvick <chris@rorvick.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The correct spelling includes the space.  Fix this in strings and
comments that refer to the manufacturer.
Signed-off-by: NChris Rorvick <chris@rorvick.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Instead of sysfs and the conditional build with Kconfig, implement the
handling of the impulse response controls via control API, and always
enable the build.  Two new controls, "Impulse Response Volume" and
"Impulse Response Period" are added as a replacement for the former
sysfs files.
Tested-by: NChris Rorvick <chris@rorvick.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Promote line6 driver from staging to sound/usb/line6 directory, and
maintain through sound subsystem tree.

This commit just moves the code and adapts Makefile / Kconfig.
The further renames and misc cleanups will follow.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The device type can now be used to determine the addresses of the
audio endpoints for the interface.  Drop the conditional logic and make
these values properties.
Signed-off-by: NChris Rorvick <chris@rorvick.com>
Reviewed-by: NStefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The `device_bit' member was no longer used as of commit 28079044
(staging: line6: drop MIDI parameter sysfs attrs).
Signed-off-by: NChris Rorvick <chris@rorvick.com>
Reviewed-by: NStefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Fix three space prohibited errors in pcm.h found by checkpatch.pl.
Signed-off-by: NJonas Lundqvist <jonas@gannon.se>
Reviewed-by: NJeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Signed-off-by: NStefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There are several features of the Line6 USB driver which require PCM
data to be exchanged with the device:
*) PCM playback and capture via ALSA
*) software monitoring (for devices without hardware monitoring)
*) optional impulse response measurement
However, from the device's point of view, there is just a single
capture and playback stream, which must be shared between these
subsystems. It is therefore necessary to maintain the state of the
subsystems with respect to PCM usage. We define several constants of
the form LINE6_BIT_PCM_<subsystem>_<direction>_<resource> with the
following meanings:
*) <subsystem> is one of
-) ALSA: PCM playback and capture via ALSA
-) MONITOR: software monitoring
-) IMPULSE: optional impulse response measurement
*) <direction> is one of
-) PLAYBACK: audio output (from host to device)
-) CAPTURE: audio input (from device to host)
*) <resource> is one of
-) BUFFER: buffer required by PCM data stream
-) STREAM: actual PCM data stream

The subsystems call line6_pcm_acquire() to acquire the (shared)
resources needed for a particular operation (e.g., allocate the buffer
for ALSA playback or start the capture stream for software monitoring).
When a resource is no longer needed, it is released by calling
line6_pcm_release(). Buffer allocation and stream startup are handled
separately to allow the ALSA kernel driver to perform them at
appropriate places (since the callback which starts a PCM stream is not
allowed to sleep).
Signed-off-by: NMarkus Grabner <grabner@icg.tugraz.at>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NMarkus Grabner <grabner@icg.tugraz.at>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Playback urbs use the index_out counter to decide which part of the
playback buffer to use.  Since the urb already has a unique index in
range [0, LINE6_ISO_BUFFERS) there is no need to keep a separate
counter.

Use the urb index instead.  This also eliminates the possibility of two
urbs using the same playback buffer space if they ever complete
out-of-order for some reason.
Signed-off-by: NStefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: NMarkus Grabner <grabner@icg.tugraz.at>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch removes experimental code which is no longer used.
Signed-off-by: NMarkus Grabner <grabner@icg.tugraz.at>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This fixes up all of the remaining coding style issues that
make any sense to make in the line6 driver.

Cc: Markus Grabner <grabner@icg.tugraz.at>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Everything should be in sync now.
Signed-off-by: NMarkus Grabner <grabner@icg.tugraz.at>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Big upstream sync.
Signed-off-by: NMarkus Grabner <grabner@icg.tugraz.at>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Mostly all line length issues.
Skipped the control.h file as it makes sense to leave it alone.

Cc: Markus Grabner <grabner@icg.tugraz.at>
Cc: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This is an experimental Linux driver for the guitar amp, cab, and
effects modeller PODxt Pro by Line6 (and similar devices), supporting
the following features:

  - Reading/writing individual parameters
  - Reading/writing complete channel, effects setup, and amp setup data
  - Channel switching
  - Virtual MIDI interface
  - Tuner access
  - Playback/capture/mixer device for any  ALSA-compatible PCM audio
    application
  - Signal routing (record clean/processed  guitar signal, re-amping)

Moreover, preliminary support for the Variax Workbench is included.

From: Markus Grabner <grabner@icg.tugraz.at>
Cc: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>