drivers/staging/line6/pcm.h

   1 /*
   2  * Line6 Linux USB driver - 0.9.1beta
   3  *
   4  * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License as
   8  *      published by the Free Software Foundation, version 2.
   9  *
  10  */
  11
  12 /*
  13         PCM interface to POD series devices.
  14 */
  15
  16 #ifndef PCM_H
  17 #define PCM_H
  18
  19 #include <sound/pcm.h>
  20
  21 #include "driver.h"
  22 #include "usbdefs.h"
  23
  24 /* number of URBs */
  25 #define LINE6_ISO_BUFFERS       2
  26
  27 /*
  28         number of USB frames per URB
  29         The Line6 Windows driver always transmits two frames per packet, but
  30         the Linux driver performs significantly better (i.e., lower latency)
  31         with only one frame per packet.
  32 */
  33 #define LINE6_ISO_PACKETS       1
  34
  35 /* in a "full speed" device (such as the PODxt Pro) this means 1ms */
  36 #define LINE6_ISO_INTERVAL      1
  37
  38 #ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
  39 #define LINE6_IMPULSE_DEFAULT_PERIOD 100
  40 #endif
  41
  42 /*
  43         Get substream from Line6 PCM data structure
  44 */
  45 #define get_substream(line6pcm, stream) \
  46                 (line6pcm->pcm->streams[stream].substream)
  47
  48 /*
  49         PCM mode bits.
  50
  51         There are several features of the Line6 USB driver which require PCM
  52         data to be exchanged with the device:
  53         *) PCM playback and capture via ALSA
  54         *) software monitoring (for devices without hardware monitoring)
  55         *) optional impulse response measurement
  56         However, from the device's point of view, there is just a single
  57         capture and playback stream, which must be shared between these
  58         subsystems. It is therefore necessary to maintain the state of the
  59         subsystems with respect to PCM usage. We define several constants of
  60         the form LINE6_BIT_PCM_<subsystem>_<direction>_<resource> with the
  61         following meanings:
  62         *) <subsystem> is one of
  63         -) ALSA: PCM playback and capture via ALSA
  64         -) MONITOR: software monitoring
  65         -) IMPULSE: optional impulse response measurement
  66         *) <direction> is one of
  67         -) PLAYBACK: audio output (from host to device)
  68         -) CAPTURE: audio input (from device to host)
  69         *) <resource> is one of
  70         -) BUFFER: buffer required by PCM data stream
  71         -) STREAM: actual PCM data stream
  72
  73         The subsystems call line6_pcm_acquire() to acquire the (shared)
  74         resources needed for a particular operation (e.g., allocate the buffer
  75         for ALSA playback or start the capture stream for software monitoring).
  76         When a resource is no longer needed, it is released by calling
  77         line6_pcm_release(). Buffer allocation and stream startup are handled
  78         separately to allow the ALSA kernel driver to perform them at
  79         appropriate places (since the callback which starts a PCM stream is not
  80         allowed to sleep).
  81 */
  82 enum {
  83         /* individual bit indices: */
  84         LINE6_INDEX_PCM_ALSA_PLAYBACK_BUFFER,
  85         LINE6_INDEX_PCM_ALSA_PLAYBACK_STREAM,
  86         LINE6_INDEX_PCM_ALSA_CAPTURE_BUFFER,
  87         LINE6_INDEX_PCM_ALSA_CAPTURE_STREAM,
  88         LINE6_INDEX_PCM_MONITOR_PLAYBACK_BUFFER,
  89         LINE6_INDEX_PCM_MONITOR_PLAYBACK_STREAM,
  90         LINE6_INDEX_PCM_MONITOR_CAPTURE_BUFFER,
  91         LINE6_INDEX_PCM_MONITOR_CAPTURE_STREAM,
  92 #ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
  93         LINE6_INDEX_PCM_IMPULSE_PLAYBACK_BUFFER,
  94         LINE6_INDEX_PCM_IMPULSE_PLAYBACK_STREAM,
  95         LINE6_INDEX_PCM_IMPULSE_CAPTURE_BUFFER,
  96         LINE6_INDEX_PCM_IMPULSE_CAPTURE_STREAM,
  97 #endif
  98         LINE6_INDEX_PAUSE_PLAYBACK,
  99         LINE6_INDEX_PREPARED,
 100
 101         /* individual bit masks: */
 102         LINE6_BIT(PCM_ALSA_PLAYBACK_BUFFER),
 103         LINE6_BIT(PCM_ALSA_PLAYBACK_STREAM),
 104         LINE6_BIT(PCM_ALSA_CAPTURE_BUFFER),
 105         LINE6_BIT(PCM_ALSA_CAPTURE_STREAM),
 106         LINE6_BIT(PCM_MONITOR_PLAYBACK_BUFFER),
 107         LINE6_BIT(PCM_MONITOR_PLAYBACK_STREAM),
 108         LINE6_BIT(PCM_MONITOR_CAPTURE_BUFFER),
 109         LINE6_BIT(PCM_MONITOR_CAPTURE_STREAM),
 110 #ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
 111         LINE6_BIT(PCM_IMPULSE_PLAYBACK_BUFFER),
 112         LINE6_BIT(PCM_IMPULSE_PLAYBACK_STREAM),
 113         LINE6_BIT(PCM_IMPULSE_CAPTURE_BUFFER),
 114         LINE6_BIT(PCM_IMPULSE_CAPTURE_STREAM),
 115 #endif
 116         LINE6_BIT(PAUSE_PLAYBACK),
 117         LINE6_BIT(PREPARED),
 118
 119         /* combined bit masks (by operation): */
 120         LINE6_BITS_PCM_ALSA_BUFFER =
 121             LINE6_BIT_PCM_ALSA_PLAYBACK_BUFFER |
 122             LINE6_BIT_PCM_ALSA_CAPTURE_BUFFER,
 123
 124         LINE6_BITS_PCM_ALSA_STREAM =
 125             LINE6_BIT_PCM_ALSA_PLAYBACK_STREAM |
 126             LINE6_BIT_PCM_ALSA_CAPTURE_STREAM,
 127
 128         LINE6_BITS_PCM_MONITOR =
 129             LINE6_BIT_PCM_MONITOR_PLAYBACK_BUFFER |
 130             LINE6_BIT_PCM_MONITOR_PLAYBACK_STREAM |
 131             LINE6_BIT_PCM_MONITOR_CAPTURE_BUFFER |
 132             LINE6_BIT_PCM_MONITOR_CAPTURE_STREAM,
 133
 134 #ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
 135         LINE6_BITS_PCM_IMPULSE =
 136             LINE6_BIT_PCM_IMPULSE_PLAYBACK_BUFFER |
 137             LINE6_BIT_PCM_IMPULSE_PLAYBACK_STREAM |
 138             LINE6_BIT_PCM_IMPULSE_CAPTURE_BUFFER |
 139             LINE6_BIT_PCM_IMPULSE_CAPTURE_STREAM,
 140 #endif
 141
 142         /* combined bit masks (by direction): */
 143         LINE6_BITS_PLAYBACK_BUFFER =
 144 #ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
 145             LINE6_BIT_PCM_IMPULSE_PLAYBACK_BUFFER |
 146 #endif
 147             LINE6_BIT_PCM_ALSA_PLAYBACK_BUFFER |
 148             LINE6_BIT_PCM_MONITOR_PLAYBACK_BUFFER ,
 149
 150         LINE6_BITS_PLAYBACK_STREAM =
 151 #ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
 152             LINE6_BIT_PCM_IMPULSE_PLAYBACK_STREAM |
 153 #endif
 154             LINE6_BIT_PCM_ALSA_PLAYBACK_STREAM |
 155             LINE6_BIT_PCM_MONITOR_PLAYBACK_STREAM ,
 156
 157         LINE6_BITS_CAPTURE_BUFFER =
 158 #ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
 159             LINE6_BIT_PCM_IMPULSE_CAPTURE_BUFFER |
 160 #endif
 161             LINE6_BIT_PCM_ALSA_CAPTURE_BUFFER |
 162             LINE6_BIT_PCM_MONITOR_CAPTURE_BUFFER ,
 163
 164         LINE6_BITS_CAPTURE_STREAM =
 165 #ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
 166             LINE6_BIT_PCM_IMPULSE_CAPTURE_STREAM |
 167 #endif
 168             LINE6_BIT_PCM_ALSA_CAPTURE_STREAM |
 169             LINE6_BIT_PCM_MONITOR_CAPTURE_STREAM,
 170
 171         LINE6_BITS_STREAM =
 172             LINE6_BITS_PLAYBACK_STREAM |
 173             LINE6_BITS_CAPTURE_STREAM
 174 };
 175
 176 struct line6_pcm_properties {
 177         struct snd_pcm_hardware snd_line6_playback_hw, snd_line6_capture_hw;
 178         struct snd_pcm_hw_constraint_ratdens snd_line6_rates;
 179         int bytes_per_frame;
 180 };
 181
 182 struct snd_line6_pcm {
 183         /**
 184                  Pointer back to the Line6 driver data structure.
 185         */
 186         struct usb_line6 *line6;
 187
 188         /**
 189                  Properties.
 190         */
 191         struct line6_pcm_properties *properties;
 192
 193         /**
 194                  ALSA pcm stream
 195         */
 196         struct snd_pcm *pcm;
 197
 198         /**
 199                  URBs for audio playback.
 200         */
 201         struct urb *urb_audio_out[LINE6_ISO_BUFFERS];
 202
 203         /**
 204                  URBs for audio capture.
 205         */
 206         struct urb *urb_audio_in[LINE6_ISO_BUFFERS];
 207
 208         /**
 209                  Temporary buffer for playback.
 210                  Since the packet size is not known in advance, this buffer is
 211                  large enough to store maximum size packets.
 212         */
 213         unsigned char *buffer_out;
 214
 215         /**
 216                  Temporary buffer for capture.
 217                  Since the packet size is not known in advance, this buffer is
 218                  large enough to store maximum size packets.
 219         */
 220         unsigned char *buffer_in;
 221
 222         /**
 223                  Previously captured frame (for software monitoring).
 224         */
 225         unsigned char *prev_fbuf;
 226
 227         /**
 228                  Size of previously captured frame (for software monitoring).
 229         */
 230         int prev_fsize;
 231
 232         /**
 233                  Free frame position in the playback buffer.
 234         */
 235         snd_pcm_uframes_t pos_out;
 236
 237         /**
 238                  Count processed bytes for playback.
 239                  This is modulo period size (to determine when a period is
 240                  finished).
 241         */
 242         unsigned bytes_out;
 243
 244         /**
 245                  Counter to create desired playback sample rate.
 246         */
 247         unsigned count_out;
 248
 249         /**
 250                  Playback period size in bytes
 251         */
 252         unsigned period_out;
 253
 254         /**
 255                  Processed frame position in the playback buffer.
 256                  The contents of the output ring buffer have been consumed by
 257                  the USB subsystem (i.e., sent to the USB device) up to this
 258                  position.
 259         */
 260         snd_pcm_uframes_t pos_out_done;
 261
 262         /**
 263                  Count processed bytes for capture.
 264                  This is modulo period size (to determine when a period is
 265                  finished).
 266         */
 267         unsigned bytes_in;
 268
 269         /**
 270                  Counter to create desired capture sample rate.
 271         */
 272         unsigned count_in;
 273
 274         /**
 275                  Capture period size in bytes
 276         */
 277         unsigned period_in;
 278
 279         /**
 280                  Processed frame position in the capture buffer.
 281                  The contents of the output ring buffer have been consumed by
 282                  the USB subsystem (i.e., sent to the USB device) up to this
 283                  position.
 284         */
 285         snd_pcm_uframes_t pos_in_done;
 286
 287         /**
 288                  Bit mask of active playback URBs.
 289         */
 290         unsigned long active_urb_out;
 291
 292         /**
 293                  Maximum size of USB packet.
 294         */
 295         int max_packet_size;
 296
 297         /**
 298                  USB endpoint for listening to audio data.
 299         */
 300         int ep_audio_read;
 301
 302         /**
 303                  USB endpoint for writing audio data.
 304         */
 305         int ep_audio_write;
 306
 307         /**
 308                  Bit mask of active capture URBs.
 309         */
 310         unsigned long active_urb_in;
 311
 312         /**
 313                  Bit mask of playback URBs currently being unlinked.
 314         */
 315         unsigned long unlink_urb_out;
 316
 317         /**
 318                  Bit mask of capture URBs currently being unlinked.
 319         */
 320         unsigned long unlink_urb_in;
 321
 322         /**
 323                  Spin lock to protect updates of the playback buffer positions (not
 324                  contents!)
 325         */
 326         spinlock_t lock_audio_out;
 327
 328         /**
 329                  Spin lock to protect updates of the capture buffer positions (not
 330                  contents!)
 331         */
 332         spinlock_t lock_audio_in;
 333
 334         /**
 335                  Spin lock to protect trigger.
 336         */
 337         spinlock_t lock_trigger;
 338
 339         /**
 340                  PCM playback volume (left and right).
 341         */
 342         int volume_playback[2];
 343
 344         /**
 345                  PCM monitor volume.
 346         */
 347         int volume_monitor;
 348
 349 #ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
 350         /**
 351                  Volume of impulse response test signal (if zero, test is disabled).
 352         */
 353         int impulse_volume;
 354
 355         /**
 356                  Period of impulse response test signal.
 357         */
 358         int impulse_period;
 359
 360         /**
 361                  Counter for impulse response test signal.
 362         */
 363         int impulse_count;
 364 #endif
 365
 366         /**
 367                  Several status bits (see LINE6_BIT_*).
 368         */
 369         unsigned long flags;
 370
 371         int last_frame_in, last_frame_out;
 372 };
 373
 374 extern int line6_init_pcm(struct usb_line6 *line6,
 375                           struct line6_pcm_properties *properties);
 376 extern int snd_line6_trigger(struct snd_pcm_substream *substream, int cmd);
 377 extern int snd_line6_prepare(struct snd_pcm_substream *substream);
 378 extern void line6_pcm_disconnect(struct snd_line6_pcm *line6pcm);
 379 extern int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int channels);
 380 extern int line6_pcm_release(struct snd_line6_pcm *line6pcm, int channels);
 381
 382 #endif