xref: /linux/sound/core/seq/oss/seq_oss.c (revision ca853314e78b0a65c20b6a889a23c31f918d4aa2)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * OSS compatible sequencer driver
4  *
5  * registration of device and proc
6  *
7  * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
8  */
9 
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/mutex.h>
13 #include <linux/compat.h>
14 #include <sound/core.h>
15 #include <sound/minors.h>
16 #include <sound/initval.h>
17 #include "seq_oss_device.h"
18 #include "seq_oss_synth.h"
19 
20 /*
21  * module option
22  */
23 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
24 MODULE_DESCRIPTION("OSS-compatible sequencer module");
25 MODULE_LICENSE("GPL");
26 /* Takashi says this is really only for sound-service-0-, but this is OK. */
27 MODULE_ALIAS_SNDRV_MINOR(SNDRV_MINOR_OSS_SEQUENCER);
28 MODULE_ALIAS_SNDRV_MINOR(SNDRV_MINOR_OSS_MUSIC);
29 
30 
31 /*
32  * prototypes
33  */
34 static int register_device(void);
35 static void unregister_device(void);
36 #ifdef CONFIG_SND_PROC_FS
37 static int register_proc(void);
38 static void unregister_proc(void);
39 #else
40 static inline int register_proc(void) { return 0; }
41 static inline void unregister_proc(void) {}
42 #endif
43 
44 static int odev_open(struct inode *inode, struct file *file);
45 static int odev_release(struct inode *inode, struct file *file);
46 static ssize_t odev_read(struct file *file, char __user *buf, size_t count, loff_t *offset);
47 static ssize_t odev_write(struct file *file, const char __user *buf, size_t count, loff_t *offset);
48 static long odev_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
49 static __poll_t odev_poll(struct file *file, poll_table * wait);
50 
51 
52 /*
53  * module interface
54  */
55 
56 static struct snd_seq_driver seq_oss_synth_driver = {
57 	.driver = {
58 		.name = KBUILD_MODNAME,
59 		.probe = snd_seq_oss_synth_probe,
60 		.remove = snd_seq_oss_synth_remove,
61 	},
62 	.id = SNDRV_SEQ_DEV_ID_OSS,
63 	.argsize = sizeof(struct snd_seq_oss_reg),
64 };
65 
66 static int __init alsa_seq_oss_init(void)
67 {
68 	int rc;
69 
70 	if ((rc = register_device()) < 0)
71 		goto error;
72 	if ((rc = register_proc()) < 0) {
73 		unregister_device();
74 		goto error;
75 	}
76 	if ((rc = snd_seq_oss_create_client()) < 0) {
77 		unregister_proc();
78 		unregister_device();
79 		goto error;
80 	}
81 
82 	rc = snd_seq_driver_register(&seq_oss_synth_driver);
83 	if (rc < 0) {
84 		snd_seq_oss_delete_client();
85 		unregister_proc();
86 		unregister_device();
87 		goto error;
88 	}
89 
90 	/* success */
91 	snd_seq_oss_synth_init();
92 
93  error:
94 	return rc;
95 }
96 
97 static void __exit alsa_seq_oss_exit(void)
98 {
99 	snd_seq_driver_unregister(&seq_oss_synth_driver);
100 	snd_seq_oss_delete_client();
101 	unregister_proc();
102 	unregister_device();
103 }
104 
105 module_init(alsa_seq_oss_init)
106 module_exit(alsa_seq_oss_exit)
107 
108 /*
109  * ALSA minor device interface
110  */
111 
112 static DEFINE_MUTEX(register_mutex);
113 
114 static int
115 odev_open(struct inode *inode, struct file *file)
116 {
117 	int level, rc;
118 
119 	if (iminor(inode) == SNDRV_MINOR_OSS_MUSIC)
120 		level = SNDRV_SEQ_OSS_MODE_MUSIC;
121 	else
122 		level = SNDRV_SEQ_OSS_MODE_SYNTH;
123 
124 	mutex_lock(&register_mutex);
125 	rc = snd_seq_oss_open(file, level);
126 	mutex_unlock(&register_mutex);
127 
128 	return rc;
129 }
130 
131 static int
132 odev_release(struct inode *inode, struct file *file)
133 {
134 	struct seq_oss_devinfo *dp;
135 
136 	if ((dp = file->private_data) == NULL)
137 		return 0;
138 
139 	mutex_lock(&register_mutex);
140 	snd_seq_oss_release(dp);
141 	mutex_unlock(&register_mutex);
142 
143 	return 0;
144 }
145 
146 static ssize_t
147 odev_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
148 {
149 	struct seq_oss_devinfo *dp;
150 	dp = file->private_data;
151 	if (snd_BUG_ON(!dp))
152 		return -ENXIO;
153 	return snd_seq_oss_read(dp, buf, count);
154 }
155 
156 
157 static ssize_t
158 odev_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
159 {
160 	struct seq_oss_devinfo *dp;
161 	dp = file->private_data;
162 	if (snd_BUG_ON(!dp))
163 		return -ENXIO;
164 	return snd_seq_oss_write(dp, buf, count, file);
165 }
166 
167 static long
168 odev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
169 {
170 	struct seq_oss_devinfo *dp;
171 	long rc;
172 
173 	dp = file->private_data;
174 	if (snd_BUG_ON(!dp))
175 		return -ENXIO;
176 
177 	if (cmd != SNDCTL_SEQ_SYNC &&
178 	    mutex_lock_interruptible(&register_mutex))
179 		return -ERESTARTSYS;
180 	rc = snd_seq_oss_ioctl(dp, cmd, arg);
181 	if (cmd != SNDCTL_SEQ_SYNC)
182 		mutex_unlock(&register_mutex);
183 	return rc;
184 }
185 
186 #ifdef CONFIG_COMPAT
187 static long odev_ioctl_compat(struct file *file, unsigned int cmd,
188 			      unsigned long arg)
189 {
190 	return odev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
191 }
192 #else
193 #define odev_ioctl_compat	NULL
194 #endif
195 
196 static __poll_t
197 odev_poll(struct file *file, poll_table * wait)
198 {
199 	struct seq_oss_devinfo *dp;
200 	dp = file->private_data;
201 	if (snd_BUG_ON(!dp))
202 		return EPOLLERR;
203 	return snd_seq_oss_poll(dp, file, wait);
204 }
205 
206 /*
207  * registration of sequencer minor device
208  */
209 
210 static const struct file_operations seq_oss_f_ops =
211 {
212 	.owner =	THIS_MODULE,
213 	.read =		odev_read,
214 	.write =	odev_write,
215 	.open =		odev_open,
216 	.release =	odev_release,
217 	.poll =		odev_poll,
218 	.unlocked_ioctl =	odev_ioctl,
219 	.compat_ioctl =	odev_ioctl_compat,
220 	.llseek =	noop_llseek,
221 };
222 
223 static int __init
224 register_device(void)
225 {
226 	int rc;
227 
228 	mutex_lock(&register_mutex);
229 	if ((rc = snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_SEQUENCER,
230 					  NULL, 0,
231 					  &seq_oss_f_ops, NULL)) < 0) {
232 		pr_err("ALSA: seq_oss: can't register device seq\n");
233 		mutex_unlock(&register_mutex);
234 		return rc;
235 	}
236 	if ((rc = snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_MUSIC,
237 					  NULL, 0,
238 					  &seq_oss_f_ops, NULL)) < 0) {
239 		pr_err("ALSA: seq_oss: can't register device music\n");
240 		snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_SEQUENCER, NULL, 0);
241 		mutex_unlock(&register_mutex);
242 		return rc;
243 	}
244 	mutex_unlock(&register_mutex);
245 	return 0;
246 }
247 
248 static void
249 unregister_device(void)
250 {
251 	mutex_lock(&register_mutex);
252 	if (snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MUSIC, NULL, 0) < 0)
253 		pr_err("ALSA: seq_oss: error unregister device music\n");
254 	if (snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_SEQUENCER, NULL, 0) < 0)
255 		pr_err("ALSA: seq_oss: error unregister device seq\n");
256 	mutex_unlock(&register_mutex);
257 }
258 
259 /*
260  * /proc interface
261  */
262 
263 #ifdef CONFIG_SND_PROC_FS
264 
265 static struct snd_info_entry *info_entry;
266 
267 static void
268 info_read(struct snd_info_entry *entry, struct snd_info_buffer *buf)
269 {
270 	mutex_lock(&register_mutex);
271 	snd_iprintf(buf, "OSS sequencer emulation version %s\n", SNDRV_SEQ_OSS_VERSION_STR);
272 	snd_seq_oss_system_info_read(buf);
273 	snd_seq_oss_synth_info_read(buf);
274 	snd_seq_oss_midi_info_read(buf);
275 	mutex_unlock(&register_mutex);
276 }
277 
278 
279 static int __init
280 register_proc(void)
281 {
282 	struct snd_info_entry *entry;
283 
284 	entry = snd_info_create_module_entry(THIS_MODULE, SNDRV_SEQ_OSS_PROCNAME, snd_seq_root);
285 	if (entry == NULL)
286 		return -ENOMEM;
287 
288 	entry->content = SNDRV_INFO_CONTENT_TEXT;
289 	entry->private_data = NULL;
290 	entry->c.text.read = info_read;
291 	if (snd_info_register(entry) < 0) {
292 		snd_info_free_entry(entry);
293 		return -ENOMEM;
294 	}
295 	info_entry = entry;
296 	return 0;
297 }
298 
299 static void
300 unregister_proc(void)
301 {
302 	snd_info_free_entry(info_entry);
303 	info_entry = NULL;
304 }
305 #endif /* CONFIG_SND_PROC_FS */
306