LXR linux/sound/pci/emu10k1/voice.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4 *                   Creative Labs, Inc.
   5 *                   Lee Revell <rlrevell@joe-job.com>
   6 *  Routines for control of EMU10K1 chips - voice manager
   7 *
   8 *  Rewrote voice allocator for multichannel support - rlrevell 12/2004
   9 * 
  10 *  BUGS:
  11 *    --
  12 *
  13 *  TODO:
  14 *    --
  15 */
  16
  17#include <linux/time.h>
  18#include <linux/export.h>
  19#include <sound/core.h>
  20#include <sound/emu10k1.h>
  21
  22/* Previously the voice allocator started at 0 every time.  The new voice 
  23 * allocator uses a round robin scheme.  The next free voice is tracked in 
  24 * the card record and each allocation begins where the last left off.  The 
  25 * hardware requires stereo interleaved voices be aligned to an even/odd 
  26 * boundary.  For multichannel voice allocation we ensure than the block of 
  27 * voices does not cross the 32 voice boundary.  This simplifies the 
  28 * multichannel support and ensures we can use a single write to the 
  29 * (set|clear)_loop_stop registers.  Otherwise (for example) the voices would 
  30 * get out of sync when pausing/resuming a stream.
  31 *                                                      --rlrevell
  32 */
  33
  34static int voice_alloc(struct snd_emu10k1 *emu, int type, int number,
  35                       struct snd_emu10k1_voice **rvoice)
  36{
  37        struct snd_emu10k1_voice *voice;
  38        int i, j, k, first_voice, last_voice, skip;
  39
  40        *rvoice = NULL;
  41        first_voice = last_voice = 0;
  42        for (i = emu->next_free_voice, j = 0; j < NUM_G ; i += number, j += number) {
  43                /*
  44                dev_dbg(emu->card->dev, "i %d j %d next free %d!\n",
  45                       i, j, emu->next_free_voice);
  46                */
  47                i %= NUM_G;
  48
  49                /* stereo voices must be even/odd */
  50                if ((number == 2) && (i % 2)) {
  51                        i++;
  52                        continue;
  53                }
  54                        
  55                skip = 0;
  56                for (k = 0; k < number; k++) {
  57                        voice = &emu->voices[(i+k) % NUM_G];
  58                        if (voice->use) {
  59                                skip = 1;
  60                                break;
  61                        }
  62                }
  63                if (!skip) {
  64                        /* dev_dbg(emu->card->dev, "allocated voice %d\n", i); */
  65                        first_voice = i;
  66                        last_voice = (i + number) % NUM_G;
  67                        emu->next_free_voice = last_voice;
  68                        break;
  69                }
  70        }
  71        
  72        if (first_voice == last_voice)
  73                return -ENOMEM;
  74        
  75        for (i = 0; i < number; i++) {
  76                voice = &emu->voices[(first_voice + i) % NUM_G];
  77                /*
  78                dev_dbg(emu->card->dev, "voice alloc - %i, %i of %i\n",
  79                       voice->number, idx-first_voice+1, number);
  80                */
  81                voice->use = 1;
  82                switch (type) {
  83                case EMU10K1_PCM:
  84                        voice->pcm = 1;
  85                        break;
  86                case EMU10K1_SYNTH:
  87                        voice->synth = 1;
  88                        break;
  89                case EMU10K1_MIDI:
  90                        voice->midi = 1;
  91                        break;
  92                case EMU10K1_EFX:
  93                        voice->efx = 1;
  94                        break;
  95                }
  96        }
  97        *rvoice = &emu->voices[first_voice];
  98        return 0;
  99}
 100
 101int snd_emu10k1_voice_alloc(struct snd_emu10k1 *emu, int type, int number,
 102                            struct snd_emu10k1_voice **rvoice)
 103{
 104        unsigned long flags;
 105        int result;
 106
 107        if (snd_BUG_ON(!rvoice))
 108                return -EINVAL;
 109        if (snd_BUG_ON(!number))
 110                return -EINVAL;
 111
 112        spin_lock_irqsave(&emu->voice_lock, flags);
 113        for (;;) {
 114                result = voice_alloc(emu, type, number, rvoice);
 115                if (result == 0 || type == EMU10K1_SYNTH || type == EMU10K1_MIDI)
 116                        break;
 117
 118                /* free a voice from synth */
 119                if (emu->get_synth_voice) {
 120                        result = emu->get_synth_voice(emu);
 121                        if (result >= 0) {
 122                                struct snd_emu10k1_voice *pvoice = &emu->voices[result];
 123                                pvoice->interrupt = NULL;
 124                                pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
 125                                pvoice->epcm = NULL;
 126                        }
 127                }
 128                if (result < 0)
 129                        break;
 130        }
 131        spin_unlock_irqrestore(&emu->voice_lock, flags);
 132
 133        return result;
 134}
 135
 136EXPORT_SYMBOL(snd_emu10k1_voice_alloc);
 137
 138int snd_emu10k1_voice_free(struct snd_emu10k1 *emu,
 139                           struct snd_emu10k1_voice *pvoice)
 140{
 141        unsigned long flags;
 142
 143        if (snd_BUG_ON(!pvoice))
 144                return -EINVAL;
 145        spin_lock_irqsave(&emu->voice_lock, flags);
 146        pvoice->interrupt = NULL;
 147        pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
 148        pvoice->epcm = NULL;
 149        snd_emu10k1_voice_init(emu, pvoice->number);
 150        spin_unlock_irqrestore(&emu->voice_lock, flags);
 151        return 0;
 152}
 153
 154EXPORT_SYMBOL(snd_emu10k1_voice_free);
 155