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 
19 static struct snd_minor *snd_oss_minors[SNDRV_OSS_MINORS];
20 static 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  */
snd_lookup_oss_minor_data(unsigned int minor,int type)25 void *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(&mreg->card_ptr->card_dev);
38 	} else
39 		private_data = NULL;
40 	mutex_unlock(&sound_oss_mutex);
41 	return private_data;
42 }
43 EXPORT_SYMBOL(snd_lookup_oss_minor_data);
44 
snd_oss_kernel_minor(int type,struct snd_card * card,int dev)45 static 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 
snd_register_oss_device(int type,struct snd_card * card,int dev,const struct file_operations * f_ops,void * private_data)85 int 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(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(f_ops, minor, carddev);
124 	if (register1 != minor)
125 		goto __end;
126 	if (track2 >= 0) {
127 		register2 = register_sound_special_device(f_ops, track2,
128 							  carddev);
129 		if (register2 != track2)
130 			goto __end;
131 		snd_oss_minors[track2] = preg;
132 	}
133 	mutex_unlock(&sound_oss_mutex);
134 	return 0;
135 
136       __end:
137       	if (register2 >= 0)
138       		unregister_sound_special(register2);
139       	if (register1 >= 0)
140       		unregister_sound_special(register1);
141 	snd_oss_minors[minor] = NULL;
142 	mutex_unlock(&sound_oss_mutex);
143 	kfree(preg);
144       	return -EBUSY;
145 }
146 EXPORT_SYMBOL(snd_register_oss_device);
147 
snd_unregister_oss_device(int type,struct snd_card * card,int dev)148 int 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(&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(&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(minor);
185 	if (track2 >= 0)
186 		unregister_sound_special(track2);
187 
188 	kfree(mptr);
189 	return 0;
190 }
191 EXPORT_SYMBOL(snd_unregister_oss_device);
192 
193 /*
194  *  INFO PART
195  */
196 
197 #ifdef CONFIG_SND_PROC_FS
snd_oss_device_type_name(int type)198 static 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 
snd_minor_info_oss_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)217 static 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(&sound_oss_mutex);
237 }
238 
239 
snd_minor_info_oss_init(void)240 int __init snd_minor_info_oss_init(void)
241 {
242 	struct snd_info_entry *entry;
243 
244 	entry = snd_info_create_module_entry(THIS_MODULE, "devices", 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