xref: /openbmc/linux/sound/core/sound_oss.c (revision bc5aa3a0)
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 #include <linux/init.h>
23 #include <linux/export.h>
24 #include <linux/slab.h>
25 #include <linux/time.h>
26 #include <sound/core.h>
27 #include <sound/minors.h>
28 #include <sound/info.h>
29 #include <linux/sound.h>
30 #include <linux/mutex.h>
31 
32 #define SNDRV_OSS_MINORS 256
33 
34 static struct snd_minor *snd_oss_minors[SNDRV_OSS_MINORS];
35 static DEFINE_MUTEX(sound_oss_mutex);
36 
37 /* NOTE: This function increments the refcount of the associated card like
38  * snd_lookup_minor_data(); the caller must call snd_card_unref() appropriately
39  */
40 void *snd_lookup_oss_minor_data(unsigned int minor, int type)
41 {
42 	struct snd_minor *mreg;
43 	void *private_data;
44 
45 	if (minor >= ARRAY_SIZE(snd_oss_minors))
46 		return NULL;
47 	mutex_lock(&sound_oss_mutex);
48 	mreg = snd_oss_minors[minor];
49 	if (mreg && mreg->type == type) {
50 		private_data = mreg->private_data;
51 		if (private_data && mreg->card_ptr)
52 			get_device(&mreg->card_ptr->card_dev);
53 	} else
54 		private_data = NULL;
55 	mutex_unlock(&sound_oss_mutex);
56 	return private_data;
57 }
58 
59 EXPORT_SYMBOL(snd_lookup_oss_minor_data);
60 
61 static int snd_oss_kernel_minor(int type, struct snd_card *card, int dev)
62 {
63 	int minor;
64 
65 	switch (type) {
66 	case SNDRV_OSS_DEVICE_TYPE_MIXER:
67 		if (snd_BUG_ON(!card || dev < 0 || dev > 1))
68 			return -EINVAL;
69 		minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIXER1 : SNDRV_MINOR_OSS_MIXER));
70 		break;
71 	case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
72 		minor = SNDRV_MINOR_OSS_SEQUENCER;
73 		break;
74 	case SNDRV_OSS_DEVICE_TYPE_MUSIC:
75 		minor = SNDRV_MINOR_OSS_MUSIC;
76 		break;
77 	case SNDRV_OSS_DEVICE_TYPE_PCM:
78 		if (snd_BUG_ON(!card || dev < 0 || dev > 1))
79 			return -EINVAL;
80 		minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_PCM1 : SNDRV_MINOR_OSS_PCM));
81 		break;
82 	case SNDRV_OSS_DEVICE_TYPE_MIDI:
83 		if (snd_BUG_ON(!card || dev < 0 || dev > 1))
84 			return -EINVAL;
85 		minor = SNDRV_MINOR_OSS(card->number, (dev ? SNDRV_MINOR_OSS_MIDI1 : SNDRV_MINOR_OSS_MIDI));
86 		break;
87 	case SNDRV_OSS_DEVICE_TYPE_DMFM:
88 		minor = SNDRV_MINOR_OSS(card->number, SNDRV_MINOR_OSS_DMFM);
89 		break;
90 	case SNDRV_OSS_DEVICE_TYPE_SNDSTAT:
91 		minor = SNDRV_MINOR_OSS_SNDSTAT;
92 		break;
93 	default:
94 		return -EINVAL;
95 	}
96 	if (minor < 0 || minor >= SNDRV_OSS_MINORS)
97 		return -EINVAL;
98 	return minor;
99 }
100 
101 int snd_register_oss_device(int type, struct snd_card *card, int dev,
102 			    const struct file_operations *f_ops, void *private_data)
103 {
104 	int minor = snd_oss_kernel_minor(type, card, dev);
105 	int minor_unit;
106 	struct snd_minor *preg;
107 	int cidx = SNDRV_MINOR_OSS_CARD(minor);
108 	int track2 = -1;
109 	int register1 = -1, register2 = -1;
110 	struct device *carddev = snd_card_get_device_link(card);
111 
112 	if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
113 		return 0; /* ignore silently */
114 	if (minor < 0)
115 		return minor;
116 	preg = kmalloc(sizeof(struct snd_minor), GFP_KERNEL);
117 	if (preg == NULL)
118 		return -ENOMEM;
119 	preg->type = type;
120 	preg->card = card ? card->number : -1;
121 	preg->device = dev;
122 	preg->f_ops = f_ops;
123 	preg->private_data = private_data;
124 	preg->card_ptr = card;
125 	mutex_lock(&sound_oss_mutex);
126 	snd_oss_minors[minor] = preg;
127 	minor_unit = SNDRV_MINOR_OSS_DEVICE(minor);
128 	switch (minor_unit) {
129 	case SNDRV_MINOR_OSS_PCM:
130 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
131 		break;
132 	case SNDRV_MINOR_OSS_MIDI:
133 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
134 		break;
135 	case SNDRV_MINOR_OSS_MIDI1:
136 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
137 		break;
138 	}
139 	register1 = register_sound_special_device(f_ops, minor, carddev);
140 	if (register1 != minor)
141 		goto __end;
142 	if (track2 >= 0) {
143 		register2 = register_sound_special_device(f_ops, track2,
144 							  carddev);
145 		if (register2 != track2)
146 			goto __end;
147 		snd_oss_minors[track2] = preg;
148 	}
149 	mutex_unlock(&sound_oss_mutex);
150 	return 0;
151 
152       __end:
153       	if (register2 >= 0)
154       		unregister_sound_special(register2);
155       	if (register1 >= 0)
156       		unregister_sound_special(register1);
157 	snd_oss_minors[minor] = NULL;
158 	mutex_unlock(&sound_oss_mutex);
159 	kfree(preg);
160       	return -EBUSY;
161 }
162 
163 EXPORT_SYMBOL(snd_register_oss_device);
164 
165 int snd_unregister_oss_device(int type, struct snd_card *card, int dev)
166 {
167 	int minor = snd_oss_kernel_minor(type, card, dev);
168 	int cidx = SNDRV_MINOR_OSS_CARD(minor);
169 	int track2 = -1;
170 	struct snd_minor *mptr;
171 
172 	if (card && card->number >= SNDRV_MINOR_OSS_DEVICES)
173 		return 0;
174 	if (minor < 0)
175 		return minor;
176 	mutex_lock(&sound_oss_mutex);
177 	mptr = snd_oss_minors[minor];
178 	if (mptr == NULL) {
179 		mutex_unlock(&sound_oss_mutex);
180 		return -ENOENT;
181 	}
182 	unregister_sound_special(minor);
183 	switch (SNDRV_MINOR_OSS_DEVICE(minor)) {
184 	case SNDRV_MINOR_OSS_PCM:
185 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO);
186 		break;
187 	case SNDRV_MINOR_OSS_MIDI:
188 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI);
189 		break;
190 	case SNDRV_MINOR_OSS_MIDI1:
191 		track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_DMMIDI1);
192 		break;
193 	}
194 	if (track2 >= 0) {
195 		unregister_sound_special(track2);
196 		snd_oss_minors[track2] = NULL;
197 	}
198 	snd_oss_minors[minor] = NULL;
199 	mutex_unlock(&sound_oss_mutex);
200 	kfree(mptr);
201 	return 0;
202 }
203 
204 EXPORT_SYMBOL(snd_unregister_oss_device);
205 
206 /*
207  *  INFO PART
208  */
209 
210 #ifdef CONFIG_SND_PROC_FS
211 static const char *snd_oss_device_type_name(int type)
212 {
213 	switch (type) {
214 	case SNDRV_OSS_DEVICE_TYPE_MIXER:
215 		return "mixer";
216 	case SNDRV_OSS_DEVICE_TYPE_SEQUENCER:
217 	case SNDRV_OSS_DEVICE_TYPE_MUSIC:
218 		return "sequencer";
219 	case SNDRV_OSS_DEVICE_TYPE_PCM:
220 		return "digital audio";
221 	case SNDRV_OSS_DEVICE_TYPE_MIDI:
222 		return "raw midi";
223 	case SNDRV_OSS_DEVICE_TYPE_DMFM:
224 		return "hardware dependent";
225 	default:
226 		return "?";
227 	}
228 }
229 
230 static void snd_minor_info_oss_read(struct snd_info_entry *entry,
231 				    struct snd_info_buffer *buffer)
232 {
233 	int minor;
234 	struct snd_minor *mptr;
235 
236 	mutex_lock(&sound_oss_mutex);
237 	for (minor = 0; minor < SNDRV_OSS_MINORS; ++minor) {
238 		if (!(mptr = snd_oss_minors[minor]))
239 			continue;
240 		if (mptr->card >= 0)
241 			snd_iprintf(buffer, "%3i: [%i-%2i]: %s\n", minor,
242 				    mptr->card, mptr->device,
243 				    snd_oss_device_type_name(mptr->type));
244 		else
245 			snd_iprintf(buffer, "%3i:       : %s\n", minor,
246 				    snd_oss_device_type_name(mptr->type));
247 	}
248 	mutex_unlock(&sound_oss_mutex);
249 }
250 
251 
252 int __init snd_minor_info_oss_init(void)
253 {
254 	struct snd_info_entry *entry;
255 
256 	entry = snd_info_create_module_entry(THIS_MODULE, "devices", snd_oss_root);
257 	if (!entry)
258 		return -ENOMEM;
259 	entry->c.text.read = snd_minor_info_oss_read;
260 	return snd_info_register(entry); /* freed in error path */
261 }
262 #endif /* CONFIG_SND_PROC_FS */
263