sound/pci/emu10k1/voice.c

   1 /*
   2  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   3  *                   Creative Labs, Inc.
   4  *                   Lee Revell <rlrevell@joe-job.com>
   5  *  Routines for control of EMU10K1 chips - voice manager
   6  *
   7  *  Rewrote voice allocator for multichannel support - rlrevell 12/2004
   8  *
   9  *  BUGS:
  10  *    --
  11  *
  12  *  TODO:
  13  *    --
  14  *
  15  *   This program is free software; you can redistribute it and/or modify
  16  *   it under the terms of the GNU General Public License as published by
  17  *   the Free Software Foundation; either version 2 of the License, or
  18  *   (at your option) any later version.
  19  *
  20  *   This program is distributed in the hope that it will be useful,
  21  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  *   GNU General Public License for more details.
  24  *
  25  *   You should have received a copy of the GNU General Public License
  26  *   along with this program; if not, write to the Free Software
  27  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  28  *
  29  */
  30
  31 #include <linux/time.h>
  32 #include <sound/core.h>
  33 #include <sound/emu10k1.h>
  34
  35 /* Previously the voice allocator started at 0 every time.  The new voice
  36  * allocator uses a round robin scheme.  The next free voice is tracked in
  37  * the card record and each allocation begins where the last left off.  The
  38  * hardware requires stereo interleaved voices be aligned to an even/odd
  39  * boundary.  For multichannel voice allocation we ensure than the block of
  40  * voices does not cross the 32 voice boundary.  This simplifies the
  41  * multichannel support and ensures we can use a single write to the
  42  * (set|clear)_loop_stop registers.  Otherwise (for example) the voices would
  43  * get out of sync when pausing/resuming a stream.
  44  *                                                      --rlrevell
  45  */
  46
  47 static int voice_alloc(struct snd_emu10k1 *emu, int type, int number,
  48                        struct snd_emu10k1_voice **rvoice)
  49 {
  50         struct snd_emu10k1_voice *voice;
  51         int i, j, k, first_voice, last_voice, skip;
  52
  53         *rvoice = NULL;
  54         first_voice = last_voice = 0;
  55         for (i = emu->next_free_voice, j = 0; j < NUM_G ; i += number, j += number) {
  56                 /*
  57                 printk(KERN_DEBUG "i %d j %d next free %d!\n",
  58                        i, j, emu->next_free_voice);
  59                 */
  60                 i %= NUM_G;
  61
  62                 /* stereo voices must be even/odd */
  63                 if ((number == 2) && (i % 2)) {
  64                         i++;
  65                         continue;
  66                 }
  67
  68                 skip = 0;
  69                 for (k = 0; k < number; k++) {
  70                         voice = &emu->voices[(i+k) % NUM_G];
  71                         if (voice->use) {
  72                                 skip = 1;
  73                                 break;
  74                         }
  75                 }
  76                 if (!skip) {
  77                         /* printk(KERN_DEBUG "allocated voice %d\n", i); */
  78                         first_voice = i;
  79                         last_voice = (i + number) % NUM_G;
  80                         emu->next_free_voice = last_voice;
  81                         break;
  82                 }
  83         }
  84
  85         if (first_voice == last_voice)
  86                 return -ENOMEM;
  87
  88         for (i = 0; i < number; i++) {
  89                 voice = &emu->voices[(first_voice + i) % NUM_G];
  90                 /*
  91                 printk(kERN_DEBUG "voice alloc - %i, %i of %i\n",
  92                        voice->number, idx-first_voice+1, number);
  93                 */
  94                 voice->use = 1;
  95                 switch (type) {
  96                 case EMU10K1_PCM:
  97                         voice->pcm = 1;
  98                         break;
  99                 case EMU10K1_SYNTH:
 100                         voice->synth = 1;
 101                         break;
 102                 case EMU10K1_MIDI:
 103                         voice->midi = 1;
 104                         break;
 105                 case EMU10K1_EFX:
 106                         voice->efx = 1;
 107                         break;
 108                 }
 109         }
 110         *rvoice = &emu->voices[first_voice];
 111         return 0;
 112 }
 113
 114 int snd_emu10k1_voice_alloc(struct snd_emu10k1 *emu, int type, int number,
 115                             struct snd_emu10k1_voice **rvoice)
 116 {
 117         unsigned long flags;
 118         int result;
 119
 120         if (snd_BUG_ON(!rvoice))
 121                 return -EINVAL;
 122         if (snd_BUG_ON(!number))
 123                 return -EINVAL;
 124
 125         spin_lock_irqsave(&emu->voice_lock, flags);
 126         for (;;) {
 127                 result = voice_alloc(emu, type, number, rvoice);
 128                 if (result == 0 || type == EMU10K1_SYNTH || type == EMU10K1_MIDI)
 129                         break;
 130
 131                 /* free a voice from synth */
 132                 if (emu->get_synth_voice) {
 133                         result = emu->get_synth_voice(emu);
 134                         if (result >= 0) {
 135                                 struct snd_emu10k1_voice *pvoice = &emu->voices[result];
 136                                 pvoice->interrupt = NULL;
 137                                 pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
 138                                 pvoice->epcm = NULL;
 139                         }
 140                 }
 141                 if (result < 0)
 142                         break;
 143         }
 144         spin_unlock_irqrestore(&emu->voice_lock, flags);
 145
 146         return result;
 147 }
 148
 149 EXPORT_SYMBOL(snd_emu10k1_voice_alloc);
 150
 151 int snd_emu10k1_voice_free(struct snd_emu10k1 *emu,
 152                            struct snd_emu10k1_voice *pvoice)
 153 {
 154         unsigned long flags;
 155
 156         if (snd_BUG_ON(!pvoice))
 157                 return -EINVAL;
 158         spin_lock_irqsave(&emu->voice_lock, flags);
 159         pvoice->interrupt = NULL;
 160         pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
 161         pvoice->epcm = NULL;
 162         snd_emu10k1_voice_init(emu, pvoice->number);
 163         spin_unlock_irqrestore(&emu->voice_lock, flags);
 164         return 0;
 165 }
 166
 167 EXPORT_SYMBOL(snd_emu10k1_voice_free);