sound: Add export.h for THIS_MODULE/EXPORT_SYMBOL where needed
[linux-2.6.git] / sound / pci / emu10k1 / voice.c
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
48 static 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                 printk(KERN_DEBUG "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                         /* printk(KERN_DEBUG "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                 printk(kERN_DEBUG "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
115 int 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
150 EXPORT_SYMBOL(snd_emu10k1_voice_alloc);
151
152 int 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
168 EXPORT_SYMBOL(snd_emu10k1_voice_free);