1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Advanced Linux Sound Architecture
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/init.h>
8#include <linux/export.h>
9#include <linux/slab.h>
10#include <linux/time.h>
11#include <sound/core.h>
12#include <sound/minors.h>
13#include <sound/info.h>
14#include <linux/sound.h>
15#include <linux/mutex.h>
16
17#define SNDRV_OSS_MINORS 256
18
19static struct snd_minor *snd_oss_minors[SNDRV_OSS_MINORS];
20static DEFINE_MUTEX(sound_oss_mutex);
21
22/* NOTE: This function increments the refcount of the associated card like
23 * snd_lookup_minor_data(); the caller must call snd_card_unref() appropriately
24 */
25void *snd_lookup_oss_minor_data(unsigned int minor, int type)
26{
27 struct snd_minor *mreg;
28 void *private_data;
29
30 if (minor >= ARRAY_SIZE(snd_oss_minors))
31 return NULL;
32 mutex_lock(&sound_oss_mutex);
33 mreg = snd_oss_minors[minor];
34 if (mreg && mreg->type == type) {
35 private_data = mreg->private_data;
36 if (private_data && mreg->card_ptr)
37 get_device(dev: &mreg->card_ptr->card_dev);
38 } else
39 private_data = NULL;
40 mutex_unlock(lock: &sound_oss_mutex);
41 return private_data;
42}
43EXPORT_SYMBOL(snd_lookup_oss_minor_data);
44
45static int snd_oss_kernel_minor(int type, struct snd_card *card, int dev)
46{
47 int minor;
48
49 switch (type) {
50 case SNDRV_OSS_DEVICE_TYPE_MIXER:
51 if (snd_BUG_ON(!card || dev < 0 || dev > 1))
52 return -EINVAL;
53 minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIXER1 : SNDRV_MINOR_OSS_MIXER));
54 break;
55 case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
56 minor = SNDRV_MINOR_OSS_SEQUENCER;
57 break;
58 case SNDRV_OSS_DEVICE_TYPE_MUSIC:
59 minor = SNDRV_MINOR_OSS_MUSIC;
60 break;
61 case SNDRV_OSS_DEVICE_TYPE_PCM:
62 if (snd_BUG_ON(!card || dev < 0 || dev > 1))
63 return -EINVAL;
64 minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_PCM1 : SNDRV_MINOR_OSS_PCM));
65 break;
66 case SNDRV_OSS_DEVICE_TYPE_MIDI:
67 if (snd_BUG_ON(!card || dev < 0 || dev > 1))
68 return -EINVAL;
69 minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIDI1 : SNDRV_MINOR_OSS_MIDI));
70 break;
71 case SNDRV_OSS_DEVICE_TYPE_DMFM:
72 minor = SNDRV_MINOR_OSS(card->number, SNDRV_MINOR_OSS_DMFM);
73 break;
74 case SNDRV_OSS_DEVICE_TYPE_SNDSTAT:
75 minor = SNDRV_MINOR_OSS_SNDSTAT;
76 break;
77 default:
78 return -EINVAL;
79 }
80 if (minor < 0 || minor >= SNDRV_OSS_MINORS)
81 return -EINVAL;
82 return minor;
83}
84
85int snd_register_oss_device(int type, struct snd_card *card, int dev,
86 const struct file_operations *f_ops, void *private_data)
87{
88 int minor = snd_oss_kernel_minor(type, card, dev);
89 int minor_unit;
90 struct snd_minor *preg;
91 int cidx = SNDRV_MINOR_OSS_CARD(minor);
92 int track2 = -1;
93 int register1 = -1, register2 = -1;
94 struct device *carddev = snd_card_get_device_link(card);
95
96 if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
97 return 0; /* ignore silently */
98 if (minor < 0)
99 return minor;
100 preg = kmalloc(size: sizeof(struct snd_minor), GFP_KERNEL);
101 if (preg == NULL)
102 return -ENOMEM;
103 preg->type = type;
104 preg->card = card ? card->number : -1;
105 preg->device = dev;
106 preg->f_ops = f_ops;
107 preg->private_data = private_data;
108 preg->card_ptr = card;
109 mutex_lock(&sound_oss_mutex);
110 snd_oss_minors[minor] = preg;
111 minor_unit = SNDRV_MINOR_OSS_DEVICE(minor);
112 switch (minor_unit) {
113 case SNDRV_MINOR_OSS_PCM:
114 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
115 break;
116 case SNDRV_MINOR_OSS_MIDI:
117 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
118 break;
119 case SNDRV_MINOR_OSS_MIDI1:
120 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
121 break;
122 }
123 register1 = register_sound_special_device(fops: f_ops, unit: minor, dev: carddev);
124 if (register1 != minor)
125 goto __end;
126 if (track2 >= 0) {
127 register2 = register_sound_special_device(fops: f_ops, unit: track2,
128 dev: carddev);
129 if (register2 != track2)
130 goto __end;
131 snd_oss_minors[track2] = preg;
132 }
133 mutex_unlock(lock: &sound_oss_mutex);
134 return 0;
135
136 __end:
137 if (register2 >= 0)
138 unregister_sound_special(unit: register2);
139 if (register1 >= 0)
140 unregister_sound_special(unit: register1);
141 snd_oss_minors[minor] = NULL;
142 mutex_unlock(lock: &sound_oss_mutex);
143 kfree(objp: preg);
144 return -EBUSY;
145}
146EXPORT_SYMBOL(snd_register_oss_device);
147
148int snd_unregister_oss_device(int type, struct snd_card *card, int dev)
149{
150 int minor = snd_oss_kernel_minor(type, card, dev);
151 int cidx = SNDRV_MINOR_OSS_CARD(minor);
152 int track2 = -1;
153 struct snd_minor *mptr;
154
155 if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
156 return 0;
157 if (minor < 0)
158 return minor;
159 mutex_lock(&sound_oss_mutex);
160 mptr = snd_oss_minors[minor];
161 if (mptr == NULL) {
162 mutex_unlock(lock: &sound_oss_mutex);
163 return -ENOENT;
164 }
165 switch (SNDRV_MINOR_OSS_DEVICE(minor)) {
166 case SNDRV_MINOR_OSS_PCM:
167 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
168 break;
169 case SNDRV_MINOR_OSS_MIDI:
170 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
171 break;
172 case SNDRV_MINOR_OSS_MIDI1:
173 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
174 break;
175 }
176 if (track2 >= 0)
177 snd_oss_minors[track2] = NULL;
178 snd_oss_minors[minor] = NULL;
179 mutex_unlock(lock: &sound_oss_mutex);
180
181 /* call unregister_sound_special() outside sound_oss_mutex;
182 * otherwise may deadlock, as it can trigger the release of a card
183 */
184 unregister_sound_special(unit: minor);
185 if (track2 >= 0)
186 unregister_sound_special(unit: track2);
187
188 kfree(objp: mptr);
189 return 0;
190}
191EXPORT_SYMBOL(snd_unregister_oss_device);
192
193/*
194 * INFO PART
195 */
196
197#ifdef CONFIG_SND_PROC_FS
198static const char *snd_oss_device_type_name(int type)
199{
200 switch (type) {
201 case SNDRV_OSS_DEVICE_TYPE_MIXER:
202 return "mixer";
203 case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
204 case SNDRV_OSS_DEVICE_TYPE_MUSIC:
205 return "sequencer";
206 case SNDRV_OSS_DEVICE_TYPE_PCM:
207 return "digital audio";
208 case SNDRV_OSS_DEVICE_TYPE_MIDI:
209 return "raw midi";
210 case SNDRV_OSS_DEVICE_TYPE_DMFM:
211 return "hardware dependent";
212 default:
213 return "?";
214 }
215}
216
217static void snd_minor_info_oss_read(struct snd_info_entry *entry,
218 struct snd_info_buffer *buffer)
219{
220 int minor;
221 struct snd_minor *mptr;
222
223 mutex_lock(&sound_oss_mutex);
224 for (minor = 0; minor < SNDRV_OSS_MINORS; ++minor) {
225 mptr = snd_oss_minors[minor];
226 if (!mptr)
227 continue;
228 if (mptr->card >= 0)
229 snd_iprintf(buffer, "%3i: [%i-%2i]: %s\n", minor,
230 mptr->card, mptr->device,
231 snd_oss_device_type_name(mptr->type));
232 else
233 snd_iprintf(buffer, "%3i: : %s\n", minor,
234 snd_oss_device_type_name(mptr->type));
235 }
236 mutex_unlock(lock: &sound_oss_mutex);
237}
238
239
240int __init snd_minor_info_oss_init(void)
241{
242 struct snd_info_entry *entry;
243
244 entry = snd_info_create_module_entry(THIS_MODULE, name: "devices", parent: snd_oss_root);
245 if (!entry)
246 return -ENOMEM;
247 entry->c.text.read = snd_minor_info_oss_read;
248 return snd_info_register(entry); /* freed in error path */
249}
250#endif /* CONFIG_SND_PROC_FS */
251

source code of linux/sound/core/sound_oss.c