[ALSA] dynamic minors (6/6): increase maximum number of sound cards
[linux-2.6] / sound / core / sound_oss.c
1 /*
2  *  Advanced Linux Sound Architecture
3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21
22 #include <sound/driver.h>
23
24 #ifdef CONFIG_SND_OSSEMUL
25
26 #if !defined(CONFIG_SOUND) && !(defined(MODULE) && defined(CONFIG_SOUND_MODULE))
27 #error "Enable the OSS soundcore multiplexer (CONFIG_SOUND) in the kernel."
28 #endif
29
30 #include <linux/init.h>
31 #include <linux/slab.h>
32 #include <linux/time.h>
33 #include <sound/core.h>
34 #include <sound/minors.h>
35 #include <sound/info.h>
36 #include <linux/sound.h>
37
38 #define SNDRV_OSS_MINORS 128
39
40 static struct snd_minor *snd_oss_minors[SNDRV_OSS_MINORS];
41 static DECLARE_MUTEX(sound_oss_mutex);
42
43 void *snd_lookup_oss_minor_data(unsigned int minor, int type)
44 {
45         struct snd_minor *mreg;
46         void *private_data;
47
48         if (minor > ARRAY_SIZE(snd_oss_minors))
49                 return NULL;
50         down(&sound_oss_mutex);
51         mreg = snd_oss_minors[minor];
52         if (mreg && mreg->type == type)
53                 private_data = mreg->private_data;
54         else
55                 private_data = NULL;
56         up(&sound_oss_mutex);
57         return private_data;
58 }
59
60 static int snd_oss_kernel_minor(int type, struct snd_card *card, int dev)
61 {
62         int minor;
63
64         switch (type) {
65         case SNDRV_OSS_DEVICE_TYPE_MIXER:
66                 snd_assert(card != NULL && dev <= 1, return -EINVAL);
67                 minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIXER1 : SNDRV_MINOR_OSS_MIXER));
68                 break;
69         case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
70                 minor = SNDRV_MINOR_OSS_SEQUENCER;
71                 break;
72         case SNDRV_OSS_DEVICE_TYPE_MUSIC:
73                 minor = SNDRV_MINOR_OSS_MUSIC;
74                 break;
75         case SNDRV_OSS_DEVICE_TYPE_PCM:
76                 snd_assert(card != NULL && dev <= 1, return -EINVAL);
77                 minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_PCM1 : SNDRV_MINOR_OSS_PCM));
78                 break;
79         case SNDRV_OSS_DEVICE_TYPE_MIDI:
80                 snd_assert(card != NULL && dev <= 1, return -EINVAL);
81                 minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIDI1 : SNDRV_MINOR_OSS_MIDI));
82                 break;
83         case SNDRV_OSS_DEVICE_TYPE_DMFM:
84                 minor = SNDRV_MINOR_OSS(card->number, SNDRV_MINOR_OSS_DMFM);
85                 break;
86         case SNDRV_OSS_DEVICE_TYPE_SNDSTAT:
87                 minor = SNDRV_MINOR_OSS_SNDSTAT;
88                 break;
89         default:
90                 return -EINVAL;
91         }
92         snd_assert(minor >= 0 && minor < SNDRV_OSS_MINORS, return -EINVAL);
93         return minor;
94 }
95
96 int snd_register_oss_device(int type, struct snd_card *card, int dev,
97                             struct file_operations *f_ops, void *private_data,
98                             const char *name)
99 {
100         int minor = snd_oss_kernel_minor(type, card, dev);
101         int minor_unit;
102         struct snd_minor *preg;
103         int cidx = SNDRV_MINOR_OSS_CARD(minor);
104         int track2 = -1;
105         int register1 = -1, register2 = -1;
106         struct device *carddev = NULL;
107
108         if (card && card->number >= 8)
109                 return 0; /* ignore silently */
110         if (minor < 0)
111                 return minor;
112         preg = kmalloc(sizeof(struct snd_minor), GFP_KERNEL);
113         if (preg == NULL)
114                 return -ENOMEM;
115         preg->type = type;
116         preg->card = card ? card->number : -1;
117         preg->device = dev;
118         preg->f_ops = f_ops;
119         preg->private_data = private_data;
120         down(&sound_oss_mutex);
121         snd_oss_minors[minor] = preg;
122         minor_unit = SNDRV_MINOR_OSS_DEVICE(minor);
123         switch (minor_unit) {
124         case SNDRV_MINOR_OSS_PCM:
125                 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
126                 break;
127         case SNDRV_MINOR_OSS_MIDI:
128                 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
129                 break;
130         case SNDRV_MINOR_OSS_MIDI1:
131                 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
132                 break;
133         }
134         if (card)
135                 carddev = card->dev;
136         register1 = register_sound_special_device(f_ops, minor, carddev);
137         if (register1 != minor)
138                 goto __end;
139         if (track2 >= 0) {
140                 register2 = register_sound_special_device(f_ops, track2,
141                                                           carddev);
142                 if (register2 != track2)
143                         goto __end;
144                 snd_oss_minors[track2] = preg;
145         }
146         up(&sound_oss_mutex);
147         return 0;
148
149       __end:
150         if (register2 >= 0)
151                 unregister_sound_special(register2);
152         if (register1 >= 0)
153                 unregister_sound_special(register1);
154         snd_oss_minors[minor] = NULL;
155         up(&sound_oss_mutex);
156         kfree(preg);
157         return -EBUSY;
158 }
159
160 int snd_unregister_oss_device(int type, struct snd_card *card, int dev)
161 {
162         int minor = snd_oss_kernel_minor(type, card, dev);
163         int cidx = SNDRV_MINOR_OSS_CARD(minor);
164         int track2 = -1;
165         struct snd_minor *mptr;
166
167         if (card && card->number >= 8)
168                 return 0;
169         if (minor < 0)
170                 return minor;
171         down(&sound_oss_mutex);
172         mptr = snd_oss_minors[minor];
173         if (mptr == NULL) {
174                 up(&sound_oss_mutex);
175                 return -ENOENT;
176         }
177         unregister_sound_special(minor);
178         switch (SNDRV_MINOR_OSS_DEVICE(minor)) {
179         case SNDRV_MINOR_OSS_PCM:
180                 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
181                 break;
182         case SNDRV_MINOR_OSS_MIDI:
183                 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
184                 break;
185         case SNDRV_MINOR_OSS_MIDI1:
186                 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
187                 break;
188         }
189         if (track2 >= 0) {
190                 unregister_sound_special(track2);
191                 snd_oss_minors[track2] = NULL;
192         }
193         snd_oss_minors[minor] = NULL;
194         up(&sound_oss_mutex);
195         kfree(mptr);
196         return 0;
197 }
198
199 /*
200  *  INFO PART
201  */
202
203 #ifdef CONFIG_PROC_FS
204
205 static struct snd_info_entry *snd_minor_info_oss_entry = NULL;
206
207 static const char *snd_oss_device_type_name(int type)
208 {
209         switch (type) {
210         case SNDRV_OSS_DEVICE_TYPE_MIXER:
211                 return "mixer";
212         case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
213         case SNDRV_OSS_DEVICE_TYPE_MUSIC:
214                 return "sequencer";
215         case SNDRV_OSS_DEVICE_TYPE_PCM:
216                 return "digital audio";
217         case SNDRV_OSS_DEVICE_TYPE_MIDI:
218                 return "raw midi";
219         case SNDRV_OSS_DEVICE_TYPE_DMFM:
220                 return "hardware dependent";
221         default:
222                 return "?";
223         }
224 }
225
226 static void snd_minor_info_oss_read(struct snd_info_entry *entry,
227                                     struct snd_info_buffer *buffer)
228 {
229         int minor;
230         struct snd_minor *mptr;
231
232         down(&sound_oss_mutex);
233         for (minor = 0; minor < SNDRV_OSS_MINORS; ++minor) {
234                 if (!(mptr = snd_oss_minors[minor]))
235                         continue;
236                 if (mptr->card >= 0)
237                         snd_iprintf(buffer, "%3i: [%i-%2i]: %s\n", minor,
238                                     mptr->card, mptr->device,
239                                     snd_oss_device_type_name(mptr->type));
240                 else
241                         snd_iprintf(buffer, "%3i:       : %s\n", minor,
242                                     snd_oss_device_type_name(mptr->type));
243         }
244         up(&sound_oss_mutex);
245 }
246
247 #endif /* CONFIG_PROC_FS */
248
249 int __init snd_minor_info_oss_init(void)
250 {
251 #ifdef CONFIG_PROC_FS
252         struct snd_info_entry *entry;
253
254         entry = snd_info_create_module_entry(THIS_MODULE, "devices", snd_oss_root);
255         if (entry) {
256                 entry->c.text.read_size = PAGE_SIZE;
257                 entry->c.text.read = snd_minor_info_oss_read;
258                 if (snd_info_register(entry) < 0) {
259                         snd_info_free_entry(entry);
260                         entry = NULL;
261                 }
262         }
263         snd_minor_info_oss_entry = entry;
264 #endif
265         return 0;
266 }
267
268 int __exit snd_minor_info_oss_done(void)
269 {
270 #ifdef CONFIG_PROC_FS
271         if (snd_minor_info_oss_entry)
272                 snd_info_unregister(snd_minor_info_oss_entry);
273 #endif
274         return 0;
275 }
276
277 #endif /* CONFIG_SND_OSSEMUL */