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diff --git a/sound/usb/line6/pcm.h b/sound/usb/line6/pcm.h
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+/*
+ * Line 6 Linux USB driver
+ *
+ * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2.
+ *
+ */
+
+/*
+ PCM interface to POD series devices.
+*/
+
+#ifndef PCM_H
+#define PCM_H
+
+#include <sound/pcm.h>
+
+#include "driver.h"
+#include "usbdefs.h"
+
+/* number of URBs */
+#define LINE6_ISO_BUFFERS 2
+
+/*
+ number of USB frames per URB
+ The Line 6 Windows driver always transmits two frames per packet, but
+ the Linux driver performs significantly better (i.e., lower latency)
+ with only one frame per packet.
+*/
+#define LINE6_ISO_PACKETS 1
+
+/* in a "full speed" device (such as the PODxt Pro) this means 1ms */
+#define LINE6_ISO_INTERVAL 1
+
+#define LINE6_IMPULSE_DEFAULT_PERIOD 100
+
+/*
+ Get substream from Line 6 PCM data structure
+*/
+#define get_substream(line6pcm, stream) \
+ (line6pcm->pcm->streams[stream].substream)
+
+/*
+ PCM mode bits.
+
+ There are several features of the Line 6 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).
+*/
+enum {
+ /* individual bit indices: */
+ LINE6_INDEX_PCM_ALSA_PLAYBACK_BUFFER,
+ LINE6_INDEX_PCM_ALSA_PLAYBACK_STREAM,
+ LINE6_INDEX_PCM_ALSA_CAPTURE_BUFFER,
+ LINE6_INDEX_PCM_ALSA_CAPTURE_STREAM,
+ LINE6_INDEX_PCM_MONITOR_PLAYBACK_BUFFER,
+ LINE6_INDEX_PCM_MONITOR_PLAYBACK_STREAM,
+ LINE6_INDEX_PCM_MONITOR_CAPTURE_BUFFER,
+ LINE6_INDEX_PCM_MONITOR_CAPTURE_STREAM,
+ LINE6_INDEX_PCM_IMPULSE_PLAYBACK_BUFFER,
+ LINE6_INDEX_PCM_IMPULSE_PLAYBACK_STREAM,
+ LINE6_INDEX_PCM_IMPULSE_CAPTURE_BUFFER,
+ LINE6_INDEX_PCM_IMPULSE_CAPTURE_STREAM,
+ LINE6_INDEX_PAUSE_PLAYBACK,
+ LINE6_INDEX_PREPARED,
+
+#define LINE6_BIT(x) LINE6_BIT_ ## x = 1 << LINE6_INDEX_ ## x
+
+ /* individual bit masks: */
+ LINE6_BIT(PCM_ALSA_PLAYBACK_BUFFER),
+ LINE6_BIT(PCM_ALSA_PLAYBACK_STREAM),
+ LINE6_BIT(PCM_ALSA_CAPTURE_BUFFER),
+ LINE6_BIT(PCM_ALSA_CAPTURE_STREAM),
+ LINE6_BIT(PCM_MONITOR_PLAYBACK_BUFFER),
+ LINE6_BIT(PCM_MONITOR_PLAYBACK_STREAM),
+ LINE6_BIT(PCM_MONITOR_CAPTURE_BUFFER),
+ LINE6_BIT(PCM_MONITOR_CAPTURE_STREAM),
+ LINE6_BIT(PCM_IMPULSE_PLAYBACK_BUFFER),
+ LINE6_BIT(PCM_IMPULSE_PLAYBACK_STREAM),
+ LINE6_BIT(PCM_IMPULSE_CAPTURE_BUFFER),
+ LINE6_BIT(PCM_IMPULSE_CAPTURE_STREAM),
+ LINE6_BIT(PAUSE_PLAYBACK),
+ LINE6_BIT(PREPARED),
+
+ /* combined bit masks (by operation): */
+ LINE6_BITS_PCM_ALSA_BUFFER =
+ LINE6_BIT_PCM_ALSA_PLAYBACK_BUFFER |
+ LINE6_BIT_PCM_ALSA_CAPTURE_BUFFER,
+
+ LINE6_BITS_PCM_ALSA_STREAM =
+ LINE6_BIT_PCM_ALSA_PLAYBACK_STREAM |
+ LINE6_BIT_PCM_ALSA_CAPTURE_STREAM,
+
+ LINE6_BITS_PCM_MONITOR =
+ LINE6_BIT_PCM_MONITOR_PLAYBACK_BUFFER |
+ LINE6_BIT_PCM_MONITOR_PLAYBACK_STREAM |
+ LINE6_BIT_PCM_MONITOR_CAPTURE_BUFFER |
+ LINE6_BIT_PCM_MONITOR_CAPTURE_STREAM,
+
+ LINE6_BITS_PCM_IMPULSE =
+ LINE6_BIT_PCM_IMPULSE_PLAYBACK_BUFFER |
+ LINE6_BIT_PCM_IMPULSE_PLAYBACK_STREAM |
+ LINE6_BIT_PCM_IMPULSE_CAPTURE_BUFFER |
+ LINE6_BIT_PCM_IMPULSE_CAPTURE_STREAM,
+
+ /* combined bit masks (by direction): */
+ LINE6_BITS_PLAYBACK_BUFFER =
+ LINE6_BIT_PCM_IMPULSE_PLAYBACK_BUFFER |
+ LINE6_BIT_PCM_ALSA_PLAYBACK_BUFFER |
+ LINE6_BIT_PCM_MONITOR_PLAYBACK_BUFFER,
+
+ LINE6_BITS_PLAYBACK_STREAM =
+ LINE6_BIT_PCM_IMPULSE_PLAYBACK_STREAM |
+ LINE6_BIT_PCM_ALSA_PLAYBACK_STREAM |
+ LINE6_BIT_PCM_MONITOR_PLAYBACK_STREAM,
+
+ LINE6_BITS_CAPTURE_BUFFER =
+ LINE6_BIT_PCM_IMPULSE_CAPTURE_BUFFER |
+ LINE6_BIT_PCM_ALSA_CAPTURE_BUFFER |
+ LINE6_BIT_PCM_MONITOR_CAPTURE_BUFFER,
+
+ LINE6_BITS_CAPTURE_STREAM =
+ LINE6_BIT_PCM_IMPULSE_CAPTURE_STREAM |
+ LINE6_BIT_PCM_ALSA_CAPTURE_STREAM |
+ LINE6_BIT_PCM_MONITOR_CAPTURE_STREAM,
+
+ LINE6_BITS_STREAM =
+ LINE6_BITS_PLAYBACK_STREAM |
+ LINE6_BITS_CAPTURE_STREAM
+};
+
+struct line6_pcm_properties {
+ struct snd_pcm_hardware snd_line6_playback_hw, snd_line6_capture_hw;
+ struct snd_pcm_hw_constraint_ratdens snd_line6_rates;
+ int bytes_per_frame;
+};
+
+struct snd_line6_pcm {
+ /**
+ Pointer back to the Line 6 driver data structure.
+ */
+ struct usb_line6 *line6;
+
+ /**
+ Properties.
+ */
+ struct line6_pcm_properties *properties;
+
+ /**
+ ALSA pcm stream
+ */
+ struct snd_pcm *pcm;
+
+ /**
+ URBs for audio playback.
+ */
+ struct urb *urb_audio_out[LINE6_ISO_BUFFERS];
+
+ /**
+ URBs for audio capture.
+ */
+ struct urb *urb_audio_in[LINE6_ISO_BUFFERS];
+
+ /**
+ Temporary buffer for playback.
+ Since the packet size is not known in advance, this buffer is
+ large enough to store maximum size packets.
+ */
+ unsigned char *buffer_out;
+
+ /**
+ Temporary buffer for capture.
+ Since the packet size is not known in advance, this buffer is
+ large enough to store maximum size packets.
+ */
+ unsigned char *buffer_in;
+
+ /**
+ Previously captured frame (for software monitoring).
+ */
+ unsigned char *prev_fbuf;
+
+ /**
+ Size of previously captured frame (for software monitoring).
+ */
+ int prev_fsize;
+
+ /**
+ Free frame position in the playback buffer.
+ */
+ snd_pcm_uframes_t pos_out;
+
+ /**
+ Count processed bytes for playback.
+ This is modulo period size (to determine when a period is
+ finished).
+ */
+ unsigned bytes_out;
+
+ /**
+ Counter to create desired playback sample rate.
+ */
+ unsigned count_out;
+
+ /**
+ Playback period size in bytes
+ */
+ unsigned period_out;
+
+ /**
+ Processed frame position in the playback buffer.
+ The contents of the output ring buffer have been consumed by
+ the USB subsystem (i.e., sent to the USB device) up to this
+ position.
+ */
+ snd_pcm_uframes_t pos_out_done;
+
+ /**
+ Count processed bytes for capture.
+ This is modulo period size (to determine when a period is
+ finished).
+ */
+ unsigned bytes_in;
+
+ /**
+ Counter to create desired capture sample rate.
+ */
+ unsigned count_in;
+
+ /**
+ Capture period size in bytes
+ */
+ unsigned period_in;
+
+ /**
+ Processed frame position in the capture buffer.
+ The contents of the output ring buffer have been consumed by
+ the USB subsystem (i.e., sent to the USB device) up to this
+ position.
+ */
+ snd_pcm_uframes_t pos_in_done;
+
+ /**
+ Bit mask of active playback URBs.
+ */
+ unsigned long active_urb_out;
+
+ /**
+ Maximum size of USB packet.
+ */
+ int max_packet_size;
+
+ /**
+ Bit mask of active capture URBs.
+ */
+ unsigned long active_urb_in;
+
+ /**
+ Bit mask of playback URBs currently being unlinked.
+ */
+ unsigned long unlink_urb_out;
+
+ /**
+ Bit mask of capture URBs currently being unlinked.
+ */
+ unsigned long unlink_urb_in;
+
+ /**
+ Spin lock to protect updates of the playback buffer positions (not
+ contents!)
+ */
+ spinlock_t lock_audio_out;
+
+ /**
+ Spin lock to protect updates of the capture buffer positions (not
+ contents!)
+ */
+ spinlock_t lock_audio_in;
+
+ /**
+ Spin lock to protect trigger.
+ */
+ spinlock_t lock_trigger;
+
+ /**
+ PCM playback volume (left and right).
+ */
+ int volume_playback[2];
+
+ /**
+ PCM monitor volume.
+ */
+ int volume_monitor;
+
+ /**
+ Volume of impulse response test signal (if zero, test is disabled).
+ */
+ int impulse_volume;
+
+ /**
+ Period of impulse response test signal.
+ */
+ int impulse_period;
+
+ /**
+ Counter for impulse response test signal.
+ */
+ int impulse_count;
+
+ /**
+ Several status bits (see LINE6_BIT_*).
+ */
+ unsigned long flags;
+
+ int last_frame_in, last_frame_out;
+};
+
+extern int line6_init_pcm(struct usb_line6 *line6,
+ struct line6_pcm_properties *properties);
+extern int snd_line6_trigger(struct snd_pcm_substream *substream, int cmd);
+extern int snd_line6_prepare(struct snd_pcm_substream *substream);
+extern void line6_pcm_disconnect(struct snd_line6_pcm *line6pcm);
+extern int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int channels);
+extern int line6_pcm_release(struct snd_line6_pcm *line6pcm, int channels);
+
+#endif