--- /dev/null
+/*
+ * 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:
+ * --
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#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);
Code Review / kvmfornfv.git / blobdiff