diff options
Diffstat (limited to 'sound/pci/emu10k1/voice.c')
| -rw-r--r-- | sound/pci/emu10k1/voice.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/sound/pci/emu10k1/voice.c b/sound/pci/emu10k1/voice.c new file mode 100644 index 000000000..cbeb84434 --- /dev/null +++ b/sound/pci/emu10k1/voice.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) by Jaroslav Kysela <perex@perex.cz> + * Creative Labs, Inc. + * Lee Revell <rlrevell@joe-job.com> + * Routines for control of EMU10K1 chips - voice manager + * + * Rewrote voice allocator for multichannel support - rlrevell 12/2004 + * + * BUGS: + * -- + * + * TODO: + * -- + */ + +#include <linux/time.h> +#include <linux/export.h> +#include <sound/core.h> +#include <sound/emu10k1.h> + +/* Previously the voice allocator started at 0 every time. The new voice + * allocator uses a round robin scheme. The next free voice is tracked in + * the card record and each allocation begins where the last left off. The + * hardware requires stereo interleaved voices be aligned to an even/odd + * boundary. For multichannel voice allocation we ensure than the block of + * voices does not cross the 32 voice boundary. This simplifies the + * multichannel support and ensures we can use a single write to the + * (set|clear)_loop_stop registers. Otherwise (for example) the voices would + * get out of sync when pausing/resuming a stream. + * --rlrevell + */ + +static int voice_alloc(struct snd_emu10k1 *emu, int type, int number, + struct snd_emu10k1_voice **rvoice) +{ + struct snd_emu10k1_voice *voice; + int i, j, k, first_voice, last_voice, skip; + + *rvoice = NULL; + first_voice = last_voice = 0; + for (i = emu->next_free_voice, j = 0; j < NUM_G ; i += number, j += number) { + /* + dev_dbg(emu->card->dev, "i %d j %d next free %d!\n", + i, j, emu->next_free_voice); + */ + i %= NUM_G; + + /* stereo voices must be even/odd */ + if ((number == 2) && (i % 2)) { + i++; + continue; + } + + skip = 0; + for (k = 0; k < number; k++) { + voice = &emu->voices[(i+k) % NUM_G]; + if (voice->use) { + skip = 1; + break; + } + } + if (!skip) { + /* dev_dbg(emu->card->dev, "allocated voice %d\n", i); */ + first_voice = i; + last_voice = (i + number) % NUM_G; + emu->next_free_voice = last_voice; + break; + } + } + + if (first_voice == last_voice) + return -ENOMEM; + + for (i = 0; i < number; i++) { + voice = &emu->voices[(first_voice + i) % NUM_G]; + /* + dev_dbg(emu->card->dev, "voice alloc - %i, %i of %i\n", + voice->number, idx-first_voice+1, number); + */ + voice->use = 1; + switch (type) { + case EMU10K1_PCM: + voice->pcm = 1; + break; + case EMU10K1_SYNTH: + voice->synth = 1; + break; + case EMU10K1_MIDI: + voice->midi = 1; + break; + case EMU10K1_EFX: + voice->efx = 1; + break; + } + } + *rvoice = &emu->voices[first_voice]; + return 0; +} + +int snd_emu10k1_voice_alloc(struct snd_emu10k1 *emu, int type, int number, + struct snd_emu10k1_voice **rvoice) +{ + unsigned long flags; + int result; + + if (snd_BUG_ON(!rvoice)) + return -EINVAL; + if (snd_BUG_ON(!number)) + return -EINVAL; + + spin_lock_irqsave(&emu->voice_lock, flags); + for (;;) { + result = voice_alloc(emu, type, number, rvoice); + if (result == 0 || type == EMU10K1_SYNTH || type == EMU10K1_MIDI) + break; + + /* free a voice from synth */ + if (emu->get_synth_voice) { + result = emu->get_synth_voice(emu); + if (result >= 0) { + struct snd_emu10k1_voice *pvoice = &emu->voices[result]; + pvoice->interrupt = NULL; + pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0; + pvoice->epcm = NULL; + } + } + if (result < 0) + break; + } + spin_unlock_irqrestore(&emu->voice_lock, flags); + + return result; +} + +EXPORT_SYMBOL(snd_emu10k1_voice_alloc); + +int snd_emu10k1_voice_free(struct snd_emu10k1 *emu, + struct snd_emu10k1_voice *pvoice) +{ + unsigned long flags; + + if (snd_BUG_ON(!pvoice)) + return -EINVAL; + spin_lock_irqsave(&emu->voice_lock, flags); + pvoice->interrupt = NULL; + pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0; + pvoice->epcm = NULL; + snd_emu10k1_voice_init(emu, pvoice->number); + spin_unlock_irqrestore(&emu->voice_lock, flags); + return 0; +} + +EXPORT_SYMBOL(snd_emu10k1_voice_free); |