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