20b8da250bd087190717e0f9774f9e8939e20a79
[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 <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                 /*
57                 printk(KERN_DEBUG "i %d j %d next free %d!\n",
58                        i, j, emu->next_free_voice);
59                 */
60                 i %= NUM_G;
61
62                 /* stereo voices must be even/odd */
63                 if ((number == 2) && (i % 2)) {
64                         i++;
65                         continue;
66                 }
67                         
68                 skip = 0;
69                 for (k = 0; k < number; k++) {
70                         voice = &emu->voices[(i+k) % NUM_G];
71                         if (voice->use) {
72                                 skip = 1;
73                                 break;
74                         }
75                 }
76                 if (!skip) {
77                         /* printk(KERN_DEBUG "allocated voice %d\n", i); */
78                         first_voice = i;
79                         last_voice = (i + number) % NUM_G;
80                         emu->next_free_voice = last_voice;
81                         break;
82                 }
83         }
84         
85         if (first_voice == last_voice)
86                 return -ENOMEM;
87         
88         for (i = 0; i < number; i++) {
89                 voice = &emu->voices[(first_voice + i) % NUM_G];
90                 /*
91                 printk(kERN_DEBUG "voice alloc - %i, %i of %i\n",
92                        voice->number, idx-first_voice+1, number);
93                 */
94                 voice->use = 1;
95                 switch (type) {
96                 case EMU10K1_PCM:
97                         voice->pcm = 1;
98                         break;
99                 case EMU10K1_SYNTH:
100                         voice->synth = 1;
101                         break;
102                 case EMU10K1_MIDI:
103                         voice->midi = 1;
104                         break;
105                 case EMU10K1_EFX:
106                         voice->efx = 1;
107                         break;
108                 }
109         }
110         *rvoice = &emu->voices[first_voice];
111         return 0;
112 }
113
114 int snd_emu10k1_voice_alloc(struct snd_emu10k1 *emu, int type, int number,
115                             struct snd_emu10k1_voice **rvoice)
116 {
117         unsigned long flags;
118         int result;
119
120         if (snd_BUG_ON(!rvoice))
121                 return -EINVAL;
122         if (snd_BUG_ON(!number))
123                 return -EINVAL;
124
125         spin_lock_irqsave(&emu->voice_lock, flags);
126         for (;;) {
127                 result = voice_alloc(emu, type, number, rvoice);
128                 if (result == 0 || type == EMU10K1_SYNTH || type == EMU10K1_MIDI)
129                         break;
130
131                 /* free a voice from synth */
132                 if (emu->get_synth_voice) {
133                         result = emu->get_synth_voice(emu);
134                         if (result >= 0) {
135                                 struct snd_emu10k1_voice *pvoice = &emu->voices[result];
136                                 pvoice->interrupt = NULL;
137                                 pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
138                                 pvoice->epcm = NULL;
139                         }
140                 }
141                 if (result < 0)
142                         break;
143         }
144         spin_unlock_irqrestore(&emu->voice_lock, flags);
145
146         return result;
147 }
148
149 EXPORT_SYMBOL(snd_emu10k1_voice_alloc);
150
151 int snd_emu10k1_voice_free(struct snd_emu10k1 *emu,
152                            struct snd_emu10k1_voice *pvoice)
153 {
154         unsigned long flags;
155
156         if (snd_BUG_ON(!pvoice))
157                 return -EINVAL;
158         spin_lock_irqsave(&emu->voice_lock, flags);
159         pvoice->interrupt = NULL;
160         pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
161         pvoice->epcm = NULL;
162         snd_emu10k1_voice_init(emu, pvoice->number);
163         spin_unlock_irqrestore(&emu->voice_lock, flags);
164         return 0;
165 }
166
167 EXPORT_SYMBOL(snd_emu10k1_voice_free);