Fixed MTP to work with TWRP

sound/pci/emu10k1/voice.c

@@ -0,0 +1,168 @@
+/*
+ *  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);