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: Markus Grabner <grabner@icg.tugraz.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The PCM subsystem in the Line6 driver is mainly used for PCM playback and
capture by ALSA, but also has other tasks, most notably providing a
low-latency software monitor for devices which don't support hardware
monitoring (e.g., the TonePort series). This patch makes ALSA "play nicely"
with the other components, i.e., prevents it from resetting the isochronous
USB transfer while other PCM tasks (software monitoring) are running.
Signed-off-by: Markus Grabner <grabner@icg.tugraz.at>
Signed-off-by: Greg 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: Greg 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: Greg 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: Greg Kroah-Hartman <gregkh@suse.de>
Markus Grabner