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 <linux/export.h>
33#include <sound/core.h>
34#include <sound/emu10k1.h>
35
36/* Previously the voice allocator started at 0 every time.  The new voice
37 * allocator uses a round robin scheme.  The next free voice is tracked in
38 * the card record and each allocation begins where the last left off.  The
39 * hardware requires stereo interleaved voices be aligned to an even/odd
40 * boundary.  For multichannel voice allocation we ensure than the block of
41 * voices does not cross the 32 voice boundary.  This simplifies the
42 * multichannel support and ensures we can use a single write to the
43 * (set|clear)_loop_stop registers.  Otherwise (for example) the voices would
44 * get out of sync when pausing/resuming a stream.
45 *							--rlrevell
46 */
47
48static int voice_alloc(struct snd_emu10k1 *emu, int type, int number,
49		       struct snd_emu10k1_voice **rvoice)
50{
51	struct snd_emu10k1_voice *voice;
52	int i, j, k, first_voice, last_voice, skip;
53
54	*rvoice = NULL;
55	first_voice = last_voice = 0;
56	for (i = emu->next_free_voice, j = 0; j < NUM_G ; i += number, j += number) {
57		/*
58		dev_dbg(emu->card->dev, "i %d j %d next free %d!\n",
59		       i, j, emu->next_free_voice);
60		*/
61		i %= NUM_G;
62
63		/* stereo voices must be even/odd */
64		if ((number == 2) && (i % 2)) {
65			i++;
66			continue;
67		}
68
69		skip = 0;
70		for (k = 0; k < number; k++) {
71			voice = &emu->voices[(i+k) % NUM_G];
72			if (voice->use) {
73				skip = 1;
74				break;
75			}
76		}
77		if (!skip) {
78			/* dev_dbg(emu->card->dev, "allocated voice %d\n", i); */
79			first_voice = i;
80			last_voice = (i + number) % NUM_G;
81			emu->next_free_voice = last_voice;
82			break;
83		}
84	}
85
86	if (first_voice == last_voice)
87		return -ENOMEM;
88
89	for (i = 0; i < number; i++) {
90		voice = &emu->voices[(first_voice + i) % NUM_G];
91		/*
92		dev_dbg(emu->card->dev, "voice alloc - %i, %i of %i\n",
93		       voice->number, idx-first_voice+1, number);
94		*/
95		voice->use = 1;
96		switch (type) {
97		case EMU10K1_PCM:
98			voice->pcm = 1;
99			break;
100		case EMU10K1_SYNTH:
101			voice->synth = 1;
102			break;
103		case EMU10K1_MIDI:
104			voice->midi = 1;
105			break;
106		case EMU10K1_EFX:
107			voice->efx = 1;
108			break;
109		}
110	}
111	*rvoice = &emu->voices[first_voice];
112	return 0;
113}
114
115int snd_emu10k1_voice_alloc(struct snd_emu10k1 *emu, int type, int number,
116			    struct snd_emu10k1_voice **rvoice)
117{
118	unsigned long flags;
119	int result;
120
121	if (snd_BUG_ON(!rvoice))
122		return -EINVAL;
123	if (snd_BUG_ON(!number))
124		return -EINVAL;
125
126	spin_lock_irqsave(&emu->voice_lock, flags);
127	for (;;) {
128		result = voice_alloc(emu, type, number, rvoice);
129		if (result == 0 || type == EMU10K1_SYNTH || type == EMU10K1_MIDI)
130			break;
131
132		/* free a voice from synth */
133		if (emu->get_synth_voice) {
134			result = emu->get_synth_voice(emu);
135			if (result >= 0) {
136				struct snd_emu10k1_voice *pvoice = &emu->voices[result];
137				pvoice->interrupt = NULL;
138				pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
139				pvoice->epcm = NULL;
140			}
141		}
142		if (result < 0)
143			break;
144	}
145	spin_unlock_irqrestore(&emu->voice_lock, flags);
146
147	return result;
148}
149
150EXPORT_SYMBOL(snd_emu10k1_voice_alloc);
151
152int snd_emu10k1_voice_free(struct snd_emu10k1 *emu,
153			   struct snd_emu10k1_voice *pvoice)
154{
155	unsigned long flags;
156
157	if (snd_BUG_ON(!pvoice))
158		return -EINVAL;
159	spin_lock_irqsave(&emu->voice_lock, flags);
160	pvoice->interrupt = NULL;
161	pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
162	pvoice->epcm = NULL;
163	snd_emu10k1_voice_init(emu, pvoice->number);
164	spin_unlock_irqrestore(&emu->voice_lock, flags);
165	return 0;
166}
167
168EXPORT_SYMBOL(snd_emu10k1_voice_free);
169