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 guard(mutex)(T: &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 return private_data;
41}
42EXPORT_SYMBOL(snd_lookup_oss_minor_data);
43
44static int snd_oss_kernel_minor(int type, struct snd_card *card, int dev)
45{
46 int minor;
47
48 switch (type) {
49 case SNDRV_OSS_DEVICE_TYPE_MIXER:
50 if (snd_BUG_ON(!card || dev < 0 || dev > 1))
51 return -EINVAL;
52 minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIXER1 : SNDRV_MINOR_OSS_MIXER));
53 break;
54 case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
55 minor = SNDRV_MINOR_OSS_SEQUENCER;
56 break;
57 case SNDRV_OSS_DEVICE_TYPE_MUSIC:
58 minor = SNDRV_MINOR_OSS_MUSIC;
59 break;
60 case SNDRV_OSS_DEVICE_TYPE_PCM:
61 if (snd_BUG_ON(!card || dev < 0 || dev > 1))
62 return -EINVAL;
63 minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_PCM1 : SNDRV_MINOR_OSS_PCM));
64 break;
65 case SNDRV_OSS_DEVICE_TYPE_MIDI:
66 if (snd_BUG_ON(!card || dev < 0 || dev > 1))
67 return -EINVAL;
68 minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIDI1 : SNDRV_MINOR_OSS_MIDI));
69 break;
70 case SNDRV_OSS_DEVICE_TYPE_DMFM:
71 minor = SNDRV_MINOR_OSS(card->number, SNDRV_MINOR_OSS_DMFM);
72 break;
73 case SNDRV_OSS_DEVICE_TYPE_SNDSTAT:
74 minor = SNDRV_MINOR_OSS_SNDSTAT;
75 break;
76 default:
77 return -EINVAL;
78 }
79 if (minor < 0 || minor >= SNDRV_OSS_MINORS)
80 return -EINVAL;
81 return minor;
82}
83
84int snd_register_oss_device(int type, struct snd_card *card, int dev,
85 const struct file_operations *f_ops, void *private_data)
86{
87 int minor = snd_oss_kernel_minor(type, card, dev);
88 int minor_unit;
89 struct snd_minor *preg;
90 int cidx = SNDRV_MINOR_OSS_CARD(minor);
91 int track2 = -1;
92 int register1 = -1, register2 = -1;
93 struct device *carddev = snd_card_get_device_link(card);
94
95 if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
96 return 0; /* ignore silently */
97 if (minor < 0)
98 return minor;
99 preg = kmalloc(sizeof(struct snd_minor), GFP_KERNEL);
100 if (preg == NULL)
101 return -ENOMEM;
102 preg->type = type;
103 preg->card = card ? card->number : -1;
104 preg->device = dev;
105 preg->f_ops = f_ops;
106 preg->private_data = private_data;
107 preg->card_ptr = card;
108 guard(mutex)(T: &sound_oss_mutex);
109 snd_oss_minors[minor] = preg;
110 minor_unit = SNDRV_MINOR_OSS_DEVICE(minor);
111 switch (minor_unit) {
112 case SNDRV_MINOR_OSS_PCM:
113 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
114 break;
115 case SNDRV_MINOR_OSS_MIDI:
116 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
117 break;
118 case SNDRV_MINOR_OSS_MIDI1:
119 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
120 break;
121 }
122 register1 = register_sound_special_device(fops: f_ops, unit: minor, dev: carddev);
123 if (register1 != minor)
124 goto __end;
125 if (track2 >= 0) {
126 register2 = register_sound_special_device(fops: f_ops, unit: track2,
127 dev: carddev);
128 if (register2 != track2)
129 goto __end;
130 snd_oss_minors[track2] = preg;
131 }
132 return 0;
133
134 __end:
135 if (register2 >= 0)
136 unregister_sound_special(unit: register2);
137 if (register1 >= 0)
138 unregister_sound_special(unit: register1);
139 snd_oss_minors[minor] = NULL;
140 kfree(objp: preg);
141 return -EBUSY;
142}
143EXPORT_SYMBOL(snd_register_oss_device);
144
145int snd_unregister_oss_device(int type, struct snd_card *card, int dev)
146{
147 int minor = snd_oss_kernel_minor(type, card, dev);
148 int cidx = SNDRV_MINOR_OSS_CARD(minor);
149 int track2 = -1;
150 struct snd_minor *mptr;
151
152 if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
153 return 0;
154 if (minor < 0)
155 return minor;
156 guard(mutex)(T: &sound_oss_mutex);
157 mptr = snd_oss_minors[minor];
158 if (mptr == NULL)
159 return -ENOENT;
160 switch (SNDRV_MINOR_OSS_DEVICE(minor)) {
161 case SNDRV_MINOR_OSS_PCM:
162 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
163 break;
164 case SNDRV_MINOR_OSS_MIDI:
165 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
166 break;
167 case SNDRV_MINOR_OSS_MIDI1:
168 track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
169 break;
170 }
171 if (track2 >= 0)
172 snd_oss_minors[track2] = NULL;
173 snd_oss_minors[minor] = NULL;
174
175 /* call unregister_sound_special() outside sound_oss_mutex;
176 * otherwise may deadlock, as it can trigger the release of a card
177 */
178 unregister_sound_special(unit: minor);
179 if (track2 >= 0)
180 unregister_sound_special(unit: track2);
181
182 kfree(objp: mptr);
183 return 0;
184}
185EXPORT_SYMBOL(snd_unregister_oss_device);
186
187/*
188 * INFO PART
189 */
190
191#ifdef CONFIG_SND_PROC_FS
192static const char *snd_oss_device_type_name(int type)
193{
194 switch (type) {
195 case SNDRV_OSS_DEVICE_TYPE_MIXER:
196 return "mixer";
197 case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
198 case SNDRV_OSS_DEVICE_TYPE_MUSIC:
199 return "sequencer";
200 case SNDRV_OSS_DEVICE_TYPE_PCM:
201 return "digital audio";
202 case SNDRV_OSS_DEVICE_TYPE_MIDI:
203 return "raw midi";
204 case SNDRV_OSS_DEVICE_TYPE_DMFM:
205 return "hardware dependent";
206 default:
207 return "?";
208 }
209}
210
211static void snd_minor_info_oss_read(struct snd_info_entry *entry,
212 struct snd_info_buffer *buffer)
213{
214 int minor;
215 struct snd_minor *mptr;
216
217 guard(mutex)(T: &sound_oss_mutex);
218 for (minor = 0; minor < SNDRV_OSS_MINORS; ++minor) {
219 mptr = snd_oss_minors[minor];
220 if (!mptr)
221 continue;
222 if (mptr->card >= 0)
223 snd_iprintf(buffer, "%3i: [%i-%2i]: %s\n", minor,
224 mptr->card, mptr->device,
225 snd_oss_device_type_name(mptr->type));
226 else
227 snd_iprintf(buffer, "%3i: : %s\n", minor,
228 snd_oss_device_type_name(mptr->type));
229 }
230}
231
232
233int __init snd_minor_info_oss_init(void)
234{
235 struct snd_info_entry *entry;
236
237 entry = snd_info_create_module_entry(THIS_MODULE, name: "devices", parent: snd_oss_root);
238 if (!entry)
239 return -ENOMEM;
240 entry->c.text.read = snd_minor_info_oss_read;
241 return snd_info_register(entry); /* freed in error path */
242}
243#endif /* CONFIG_SND_PROC_FS */
244

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