1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 * Creative Labs, Inc.
5 * Lee Revell <rlrevell@joe-job.com>
6 * Routines for control of EMU10K1 chips - voice manager
7 *
8 * Rewrote voice allocator for multichannel support - rlrevell 12/2004
9 *
10 * BUGS:
11 * --
12 *
13 * TODO:
14 * --
15 */
16
17 #include <linux/time.h>
18 #include <linux/export.h>
19 #include <sound/core.h>
20 #include <sound/emu10k1.h>
21
22 /* Previously the voice allocator started at 0 every time. The new voice
23 * allocator uses a round robin scheme. The next free voice is tracked in
24 * the card record and each allocation begins where the last left off. The
25 * hardware requires stereo interleaved voices be aligned to an even/odd
26 * boundary. For multichannel voice allocation we ensure than the block of
27 * voices does not cross the 32 voice boundary. This simplifies the
28 * multichannel support and ensures we can use a single write to the
29 * (set|clear)_loop_stop registers. Otherwise (for example) the voices would
30 * get out of sync when pausing/resuming a stream.
31 * --rlrevell
32 */
33
voice_alloc(struct snd_emu10k1 * emu,int type,int number,struct snd_emu10k1_voice ** rvoice)34 static int voice_alloc(struct snd_emu10k1 *emu, int type, int number,
35 struct snd_emu10k1_voice **rvoice)
36 {
37 struct snd_emu10k1_voice *voice;
38 int i, j, k, first_voice, last_voice, skip;
39
40 *rvoice = NULL;
41 first_voice = last_voice = 0;
42 for (i = emu->next_free_voice, j = 0; j < NUM_G ; i += number, j += number) {
43 /*
44 dev_dbg(emu->card->dev, "i %d j %d next free %d!\n",
45 i, j, emu->next_free_voice);
46 */
47 i %= NUM_G;
48
49 /* stereo voices must be even/odd */
50 if ((number == 2) && (i % 2)) {
51 i++;
52 continue;
53 }
54
55 skip = 0;
56 for (k = 0; k < number; k++) {
57 voice = &emu->voices[(i+k) % NUM_G];
58 if (voice->use) {
59 skip = 1;
60 break;
61 }
62 }
63 if (!skip) {
64 /* dev_dbg(emu->card->dev, "allocated voice %d\n", i); */
65 first_voice = i;
66 last_voice = (i + number) % NUM_G;
67 emu->next_free_voice = last_voice;
68 break;
69 }
70 }
71
72 if (first_voice == last_voice)
73 return -ENOMEM;
74
75 for (i = 0; i < number; i++) {
76 voice = &emu->voices[(first_voice + i) % NUM_G];
77 /*
78 dev_dbg(emu->card->dev, "voice alloc - %i, %i of %i\n",
79 voice->number, idx-first_voice+1, number);
80 */
81 voice->use = 1;
82 switch (type) {
83 case EMU10K1_PCM:
84 voice->pcm = 1;
85 break;
86 case EMU10K1_SYNTH:
87 voice->synth = 1;
88 break;
89 case EMU10K1_MIDI:
90 voice->midi = 1;
91 break;
92 case EMU10K1_EFX:
93 voice->efx = 1;
94 break;
95 }
96 }
97 *rvoice = &emu->voices[first_voice];
98 return 0;
99 }
100
snd_emu10k1_voice_alloc(struct snd_emu10k1 * emu,int type,int number,struct snd_emu10k1_voice ** rvoice)101 int snd_emu10k1_voice_alloc(struct snd_emu10k1 *emu, int type, int number,
102 struct snd_emu10k1_voice **rvoice)
103 {
104 unsigned long flags;
105 int result;
106
107 if (snd_BUG_ON(!rvoice))
108 return -EINVAL;
109 if (snd_BUG_ON(!number))
110 return -EINVAL;
111
112 spin_lock_irqsave(&emu->voice_lock, flags);
113 for (;;) {
114 result = voice_alloc(emu, type, number, rvoice);
115 if (result == 0 || type == EMU10K1_SYNTH || type == EMU10K1_MIDI)
116 break;
117
118 /* free a voice from synth */
119 if (emu->get_synth_voice) {
120 result = emu->get_synth_voice(emu);
121 if (result >= 0) {
122 struct snd_emu10k1_voice *pvoice = &emu->voices[result];
123 pvoice->interrupt = NULL;
124 pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
125 pvoice->epcm = NULL;
126 }
127 }
128 if (result < 0)
129 break;
130 }
131 spin_unlock_irqrestore(&emu->voice_lock, flags);
132
133 return result;
134 }
135
136 EXPORT_SYMBOL(snd_emu10k1_voice_alloc);
137
snd_emu10k1_voice_free(struct snd_emu10k1 * emu,struct snd_emu10k1_voice * pvoice)138 int snd_emu10k1_voice_free(struct snd_emu10k1 *emu,
139 struct snd_emu10k1_voice *pvoice)
140 {
141 unsigned long flags;
142
143 if (snd_BUG_ON(!pvoice))
144 return -EINVAL;
145 spin_lock_irqsave(&emu->voice_lock, flags);
146 pvoice->interrupt = NULL;
147 pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
148 pvoice->epcm = NULL;
149 snd_emu10k1_voice_init(emu, pvoice->number);
150 spin_unlock_irqrestore(&emu->voice_lock, flags);
151 return 0;
152 }
153
154 EXPORT_SYMBOL(snd_emu10k1_voice_free);
155