xref: /linux/sound/core/sound_oss.c (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
1 /*
2  *  Advanced Linux Sound Architecture
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.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 #ifdef CONFIG_SND_OSSEMUL
23 
24 #if !IS_ENABLED(CONFIG_SOUND)
25 #error "Enable the OSS soundcore multiplexer (CONFIG_SOUND) in the kernel."
26 #endif
27 
28 #include <linux/init.h>
29 #include <linux/export.h>
30 #include <linux/slab.h>
31 #include <linux/time.h>
32 #include <sound/core.h>
33 #include <sound/minors.h>
34 #include <sound/info.h>
35 #include <linux/sound.h>
36 #include <linux/mutex.h>
37 
38 #define SNDRV_OSS_MINORS 256
39 
40 static struct snd_minor *snd_oss_minors[SNDRV_OSS_MINORS];
41 static DEFINE_MUTEX(sound_oss_mutex);
42 
43 /* NOTE: This function increments the refcount of the associated card like
44  * snd_lookup_minor_data(); the caller must call snd_card_unref() appropriately
45  */
46 void *snd_lookup_oss_minor_data(unsigned int minor, int type)
47 {
48 	struct snd_minor *mreg;
49 	void *private_data;
50 
51 	if (minor >= ARRAY_SIZE(snd_oss_minors))
52 		return NULL;
53 	mutex_lock(&sound_oss_mutex);
54 	mreg = snd_oss_minors[minor];
55 	if (mreg && mreg->type == type) {
56 		private_data = mreg->private_data;
57 		if (private_data && mreg->card_ptr)
58 			get_device(&mreg->card_ptr->card_dev);
59 	} else
60 		private_data = NULL;
61 	mutex_unlock(&sound_oss_mutex);
62 	return private_data;
63 }
64 
65 EXPORT_SYMBOL(snd_lookup_oss_minor_data);
66 
67 static int snd_oss_kernel_minor(int type, struct snd_card *card, int dev)
68 {
69 	int minor;
70 
71 	switch (type) {
72 	case SNDRV_OSS_DEVICE_TYPE_MIXER:
73 		if (snd_BUG_ON(!card || dev < 0 || dev > 1))
74 			return -EINVAL;
75 		minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIXER1 : SNDRV_MINOR_OSS_MIXER));
76 		break;
77 	case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
78 		minor = SNDRV_MINOR_OSS_SEQUENCER;
79 		break;
80 	case SNDRV_OSS_DEVICE_TYPE_MUSIC:
81 		minor = SNDRV_MINOR_OSS_MUSIC;
82 		break;
83 	case SNDRV_OSS_DEVICE_TYPE_PCM:
84 		if (snd_BUG_ON(!card || dev < 0 || dev > 1))
85 			return -EINVAL;
86 		minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_PCM1 : SNDRV_MINOR_OSS_PCM));
87 		break;
88 	case SNDRV_OSS_DEVICE_TYPE_MIDI:
89 		if (snd_BUG_ON(!card || dev < 0 || dev > 1))
90 			return -EINVAL;
91 		minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIDI1 : SNDRV_MINOR_OSS_MIDI));
92 		break;
93 	case SNDRV_OSS_DEVICE_TYPE_DMFM:
94 		minor = SNDRV_MINOR_OSS(card->number, SNDRV_MINOR_OSS_DMFM);
95 		break;
96 	case SNDRV_OSS_DEVICE_TYPE_SNDSTAT:
97 		minor = SNDRV_MINOR_OSS_SNDSTAT;
98 		break;
99 	default:
100 		return -EINVAL;
101 	}
102 	if (minor < 0 || minor >= SNDRV_OSS_MINORS)
103 		return -EINVAL;
104 	return minor;
105 }
106 
107 int snd_register_oss_device(int type, struct snd_card *card, int dev,
108 			    const struct file_operations *f_ops, void *private_data)
109 {
110 	int minor = snd_oss_kernel_minor(type, card, dev);
111 	int minor_unit;
112 	struct snd_minor *preg;
113 	int cidx = SNDRV_MINOR_OSS_CARD(minor);
114 	int track2 = -1;
115 	int register1 = -1, register2 = -1;
116 	struct device *carddev = snd_card_get_device_link(card);
117 
118 	if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
119 		return 0; /* ignore silently */
120 	if (minor < 0)
121 		return minor;
122 	preg = kmalloc(sizeof(struct snd_minor), GFP_KERNEL);
123 	if (preg == NULL)
124 		return -ENOMEM;
125 	preg->type = type;
126 	preg->card = card ? card->number : -1;
127 	preg->device = dev;
128 	preg->f_ops = f_ops;
129 	preg->private_data = private_data;
130 	preg->card_ptr = card;
131 	mutex_lock(&sound_oss_mutex);
132 	snd_oss_minors[minor] = preg;
133 	minor_unit = SNDRV_MINOR_OSS_DEVICE(minor);
134 	switch (minor_unit) {
135 	case SNDRV_MINOR_OSS_PCM:
136 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
137 		break;
138 	case SNDRV_MINOR_OSS_MIDI:
139 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
140 		break;
141 	case SNDRV_MINOR_OSS_MIDI1:
142 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
143 		break;
144 	}
145 	register1 = register_sound_special_device(f_ops, minor, carddev);
146 	if (register1 != minor)
147 		goto __end;
148 	if (track2 >= 0) {
149 		register2 = register_sound_special_device(f_ops, track2,
150 							  carddev);
151 		if (register2 != track2)
152 			goto __end;
153 		snd_oss_minors[track2] = preg;
154 	}
155 	mutex_unlock(&sound_oss_mutex);
156 	return 0;
157 
158       __end:
159       	if (register2 >= 0)
160       		unregister_sound_special(register2);
161       	if (register1 >= 0)
162       		unregister_sound_special(register1);
163 	snd_oss_minors[minor] = NULL;
164 	mutex_unlock(&sound_oss_mutex);
165 	kfree(preg);
166       	return -EBUSY;
167 }
168 
169 EXPORT_SYMBOL(snd_register_oss_device);
170 
171 int snd_unregister_oss_device(int type, struct snd_card *card, int dev)
172 {
173 	int minor = snd_oss_kernel_minor(type, card, dev);
174 	int cidx = SNDRV_MINOR_OSS_CARD(minor);
175 	int track2 = -1;
176 	struct snd_minor *mptr;
177 
178 	if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
179 		return 0;
180 	if (minor < 0)
181 		return minor;
182 	mutex_lock(&sound_oss_mutex);
183 	mptr = snd_oss_minors[minor];
184 	if (mptr == NULL) {
185 		mutex_unlock(&sound_oss_mutex);
186 		return -ENOENT;
187 	}
188 	unregister_sound_special(minor);
189 	switch (SNDRV_MINOR_OSS_DEVICE(minor)) {
190 	case SNDRV_MINOR_OSS_PCM:
191 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
192 		break;
193 	case SNDRV_MINOR_OSS_MIDI:
194 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
195 		break;
196 	case SNDRV_MINOR_OSS_MIDI1:
197 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
198 		break;
199 	}
200 	if (track2 >= 0) {
201 		unregister_sound_special(track2);
202 		snd_oss_minors[track2] = NULL;
203 	}
204 	snd_oss_minors[minor] = NULL;
205 	mutex_unlock(&sound_oss_mutex);
206 	kfree(mptr);
207 	return 0;
208 }
209 
210 EXPORT_SYMBOL(snd_unregister_oss_device);
211 
212 /*
213  *  INFO PART
214  */
215 
216 #ifdef CONFIG_PROC_FS
217 
218 static struct snd_info_entry *snd_minor_info_oss_entry;
219 
220 static const char *snd_oss_device_type_name(int type)
221 {
222 	switch (type) {
223 	case SNDRV_OSS_DEVICE_TYPE_MIXER:
224 		return "mixer";
225 	case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
226 	case SNDRV_OSS_DEVICE_TYPE_MUSIC:
227 		return "sequencer";
228 	case SNDRV_OSS_DEVICE_TYPE_PCM:
229 		return "digital audio";
230 	case SNDRV_OSS_DEVICE_TYPE_MIDI:
231 		return "raw midi";
232 	case SNDRV_OSS_DEVICE_TYPE_DMFM:
233 		return "hardware dependent";
234 	default:
235 		return "?";
236 	}
237 }
238 
239 static void snd_minor_info_oss_read(struct snd_info_entry *entry,
240 				    struct snd_info_buffer *buffer)
241 {
242 	int minor;
243 	struct snd_minor *mptr;
244 
245 	mutex_lock(&sound_oss_mutex);
246 	for (minor = 0; minor < SNDRV_OSS_MINORS; ++minor) {
247 		if (!(mptr = snd_oss_minors[minor]))
248 			continue;
249 		if (mptr->card >= 0)
250 			snd_iprintf(buffer, "%3i: [%i-%2i]: %s\n", minor,
251 				    mptr->card, mptr->device,
252 				    snd_oss_device_type_name(mptr->type));
253 		else
254 			snd_iprintf(buffer, "%3i:       : %s\n", minor,
255 				    snd_oss_device_type_name(mptr->type));
256 	}
257 	mutex_unlock(&sound_oss_mutex);
258 }
259 
260 
261 int __init snd_minor_info_oss_init(void)
262 {
263 	struct snd_info_entry *entry;
264 
265 	entry = snd_info_create_module_entry(THIS_MODULE, "devices", snd_oss_root);
266 	if (entry) {
267 		entry->c.text.read = snd_minor_info_oss_read;
268 		if (snd_info_register(entry) < 0) {
269 			snd_info_free_entry(entry);
270 			entry = NULL;
271 		}
272 	}
273 	snd_minor_info_oss_entry = entry;
274 	return 0;
275 }
276 
277 int __exit snd_minor_info_oss_done(void)
278 {
279 	snd_info_free_entry(snd_minor_info_oss_entry);
280 	return 0;
281 }
282 #endif /* CONFIG_PROC_FS */
283 
284 #endif /* CONFIG_SND_OSSEMUL */
285