Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6] / sound / pci / emu10k1 / voice.c
1 /*
2  *  Copyright (c) by Jaroslav Kysela <perex@suse.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 <sound/driver.h>
32 #include <linux/time.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                 // printk("i %d j %d next free %d!\n", i, j, emu->next_free_voice);
58                 i %= NUM_G;
59
60                 /* stereo voices must be even/odd */
61                 if ((number == 2) && (i % 2)) {
62                         i++;
63                         continue;
64                 }
65                         
66                 skip = 0;
67                 for (k = 0; k < number; k++) {
68                         voice = &emu->voices[(i+k) % NUM_G];
69                         if (voice->use) {
70                                 skip = 1;
71                                 break;
72                         }
73                 }
74                 if (!skip) {
75                         // printk("allocated voice %d\n", i);
76                         first_voice = i;
77                         last_voice = (i + number) % NUM_G;
78                         emu->next_free_voice = last_voice;
79                         break;
80                 }
81         }
82         
83         if (first_voice == last_voice)
84                 return -ENOMEM;
85         
86         for (i = 0; i < number; i++) {
87                 voice = &emu->voices[(first_voice + i) % NUM_G];
88                 // printk("voice alloc - %i, %i of %i\n", voice->number, idx-first_voice+1, number);
89                 voice->use = 1;
90                 switch (type) {
91                 case EMU10K1_PCM:
92                         voice->pcm = 1;
93                         break;
94                 case EMU10K1_SYNTH:
95                         voice->synth = 1;
96                         break;
97                 case EMU10K1_MIDI:
98                         voice->midi = 1;
99                         break;
100                 case EMU10K1_EFX:
101                         voice->efx = 1;
102                         break;
103                 }
104         }
105         *rvoice = &emu->voices[first_voice];
106         return 0;
107 }
108
109 int snd_emu10k1_voice_alloc(struct snd_emu10k1 *emu, int type, int number,
110                             struct snd_emu10k1_voice **rvoice)
111 {
112         unsigned long flags;
113         int result;
114
115         snd_assert(rvoice != NULL, return -EINVAL);
116         snd_assert(number, return -EINVAL);
117
118         spin_lock_irqsave(&emu->voice_lock, flags);
119         for (;;) {
120                 result = voice_alloc(emu, type, number, rvoice);
121                 if (result == 0 || type == EMU10K1_SYNTH || type == EMU10K1_MIDI)
122                         break;
123
124                 /* free a voice from synth */
125                 if (emu->get_synth_voice) {
126                         result = emu->get_synth_voice(emu);
127                         if (result >= 0) {
128                                 struct snd_emu10k1_voice *pvoice = &emu->voices[result];
129                                 pvoice->interrupt = NULL;
130                                 pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
131                                 pvoice->epcm = NULL;
132                         }
133                 }
134                 if (result < 0)
135                         break;
136         }
137         spin_unlock_irqrestore(&emu->voice_lock, flags);
138
139         return result;
140 }
141
142 EXPORT_SYMBOL(snd_emu10k1_voice_alloc);
143
144 int snd_emu10k1_voice_free(struct snd_emu10k1 *emu,
145                            struct snd_emu10k1_voice *pvoice)
146 {
147         unsigned long flags;
148
149         snd_assert(pvoice != NULL, return -EINVAL);
150         spin_lock_irqsave(&emu->voice_lock, flags);
151         pvoice->interrupt = NULL;
152         pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = pvoice->efx = 0;
153         pvoice->epcm = NULL;
154         snd_emu10k1_voice_init(emu, pvoice->number);
155         spin_unlock_irqrestore(&emu->voice_lock, flags);
156         return 0;
157 }
158
159 EXPORT_SYMBOL(snd_emu10k1_voice_free);