xref: /linux/sound/core/seq/oss/seq_oss.c (revision 69bfec7548f4c1595bac0e3ddfc0458a5af31f4c)
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 	rc = register_device();
71 	if (rc < 0)
72 		goto error;
73 	rc = register_proc();
74 	if (rc < 0) {
75 		unregister_device();
76 		goto error;
77 	}
78 	rc = snd_seq_oss_create_client();
79 	if (rc < 0) {
80 		unregister_proc();
81 		unregister_device();
82 		goto error;
83 	}
84 
85 	rc = snd_seq_driver_register(&seq_oss_synth_driver);
86 	if (rc < 0) {
87 		snd_seq_oss_delete_client();
88 		unregister_proc();
89 		unregister_device();
90 		goto error;
91 	}
92 
93 	/* success */
94 	snd_seq_oss_synth_init();
95 
96  error:
97 	return rc;
98 }
99 
100 static void __exit alsa_seq_oss_exit(void)
101 {
102 	snd_seq_driver_unregister(&seq_oss_synth_driver);
103 	snd_seq_oss_delete_client();
104 	unregister_proc();
105 	unregister_device();
106 }
107 
108 module_init(alsa_seq_oss_init)
109 module_exit(alsa_seq_oss_exit)
110 
111 /*
112  * ALSA minor device interface
113  */
114 
115 static DEFINE_MUTEX(register_mutex);
116 
117 static int
118 odev_open(struct inode *inode, struct file *file)
119 {
120 	int level, rc;
121 
122 	if (iminor(inode) == SNDRV_MINOR_OSS_MUSIC)
123 		level = SNDRV_SEQ_OSS_MODE_MUSIC;
124 	else
125 		level = SNDRV_SEQ_OSS_MODE_SYNTH;
126 
127 	mutex_lock(&register_mutex);
128 	rc = snd_seq_oss_open(file, level);
129 	mutex_unlock(&register_mutex);
130 
131 	return rc;
132 }
133 
134 static int
135 odev_release(struct inode *inode, struct file *file)
136 {
137 	struct seq_oss_devinfo *dp;
138 
139 	dp = file->private_data;
140 	if (!dp)
141 		return 0;
142 
143 	mutex_lock(&register_mutex);
144 	snd_seq_oss_release(dp);
145 	mutex_unlock(&register_mutex);
146 
147 	return 0;
148 }
149 
150 static ssize_t
151 odev_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
152 {
153 	struct seq_oss_devinfo *dp;
154 	dp = file->private_data;
155 	if (snd_BUG_ON(!dp))
156 		return -ENXIO;
157 	return snd_seq_oss_read(dp, buf, count);
158 }
159 
160 
161 static ssize_t
162 odev_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
163 {
164 	struct seq_oss_devinfo *dp;
165 	dp = file->private_data;
166 	if (snd_BUG_ON(!dp))
167 		return -ENXIO;
168 	return snd_seq_oss_write(dp, buf, count, file);
169 }
170 
171 static long
172 odev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
173 {
174 	struct seq_oss_devinfo *dp;
175 	long rc;
176 
177 	dp = file->private_data;
178 	if (snd_BUG_ON(!dp))
179 		return -ENXIO;
180 
181 	if (cmd != SNDCTL_SEQ_SYNC &&
182 	    mutex_lock_interruptible(&register_mutex))
183 		return -ERESTARTSYS;
184 	rc = snd_seq_oss_ioctl(dp, cmd, arg);
185 	if (cmd != SNDCTL_SEQ_SYNC)
186 		mutex_unlock(&register_mutex);
187 	return rc;
188 }
189 
190 #ifdef CONFIG_COMPAT
191 static long odev_ioctl_compat(struct file *file, unsigned int cmd,
192 			      unsigned long arg)
193 {
194 	return odev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
195 }
196 #else
197 #define odev_ioctl_compat	NULL
198 #endif
199 
200 static __poll_t
201 odev_poll(struct file *file, poll_table * wait)
202 {
203 	struct seq_oss_devinfo *dp;
204 	dp = file->private_data;
205 	if (snd_BUG_ON(!dp))
206 		return EPOLLERR;
207 	return snd_seq_oss_poll(dp, file, wait);
208 }
209 
210 /*
211  * registration of sequencer minor device
212  */
213 
214 static const struct file_operations seq_oss_f_ops =
215 {
216 	.owner =	THIS_MODULE,
217 	.read =		odev_read,
218 	.write =	odev_write,
219 	.open =		odev_open,
220 	.release =	odev_release,
221 	.poll =		odev_poll,
222 	.unlocked_ioctl =	odev_ioctl,
223 	.compat_ioctl =	odev_ioctl_compat,
224 	.llseek =	noop_llseek,
225 };
226 
227 static int __init
228 register_device(void)
229 {
230 	int rc;
231 
232 	mutex_lock(&register_mutex);
233 	rc = snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_SEQUENCER,
234 				     NULL, 0,
235 				     &seq_oss_f_ops, NULL);
236 	if (rc < 0) {
237 		pr_err("ALSA: seq_oss: can't register device seq\n");
238 		mutex_unlock(&register_mutex);
239 		return rc;
240 	}
241 	rc = snd_register_oss_device(SNDRV_OSS_DEVICE_TYPE_MUSIC,
242 				     NULL, 0,
243 				     &seq_oss_f_ops, NULL);
244 	if (rc < 0) {
245 		pr_err("ALSA: seq_oss: can't register device music\n");
246 		snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_SEQUENCER, NULL, 0);
247 		mutex_unlock(&register_mutex);
248 		return rc;
249 	}
250 	mutex_unlock(&register_mutex);
251 	return 0;
252 }
253 
254 static void
255 unregister_device(void)
256 {
257 	mutex_lock(&register_mutex);
258 	if (snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_MUSIC, NULL, 0) < 0)
259 		pr_err("ALSA: seq_oss: error unregister device music\n");
260 	if (snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_SEQUENCER, NULL, 0) < 0)
261 		pr_err("ALSA: seq_oss: error unregister device seq\n");
262 	mutex_unlock(&register_mutex);
263 }
264 
265 /*
266  * /proc interface
267  */
268 
269 #ifdef CONFIG_SND_PROC_FS
270 
271 static struct snd_info_entry *info_entry;
272 
273 static void
274 info_read(struct snd_info_entry *entry, struct snd_info_buffer *buf)
275 {
276 	mutex_lock(&register_mutex);
277 	snd_iprintf(buf, "OSS sequencer emulation version %s\n", SNDRV_SEQ_OSS_VERSION_STR);
278 	snd_seq_oss_system_info_read(buf);
279 	snd_seq_oss_synth_info_read(buf);
280 	snd_seq_oss_midi_info_read(buf);
281 	mutex_unlock(&register_mutex);
282 }
283 
284 
285 static int __init
286 register_proc(void)
287 {
288 	struct snd_info_entry *entry;
289 
290 	entry = snd_info_create_module_entry(THIS_MODULE, SNDRV_SEQ_OSS_PROCNAME, snd_seq_root);
291 	if (entry == NULL)
292 		return -ENOMEM;
293 
294 	entry->content = SNDRV_INFO_CONTENT_TEXT;
295 	entry->private_data = NULL;
296 	entry->c.text.read = info_read;
297 	if (snd_info_register(entry) < 0) {
298 		snd_info_free_entry(entry);
299 		return -ENOMEM;
300 	}
301 	info_entry = entry;
302 	return 0;
303 }
304 
305 static void
306 unregister_proc(void)
307 {
308 	snd_info_free_entry(info_entry);
309 	info_entry = NULL;
310 }
311 #endif /* CONFIG_SND_PROC_FS */
312