xref: /linux/sound/core/hwdep.c (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Hardware dependent layer
4  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5  */
6 
7 #include <linux/major.h>
8 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/time.h>
11 #include <linux/mutex.h>
12 #include <linux/module.h>
13 #include <linux/sched/signal.h>
14 #include <sound/core.h>
15 #include <sound/control.h>
16 #include <sound/minors.h>
17 #include <sound/hwdep.h>
18 #include <sound/info.h>
19 
20 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
21 MODULE_DESCRIPTION("Hardware dependent layer");
22 MODULE_LICENSE("GPL");
23 
24 static LIST_HEAD(snd_hwdep_devices);
25 static DEFINE_MUTEX(register_mutex);
26 
27 static int snd_hwdep_dev_free(struct snd_device *device);
28 static int snd_hwdep_dev_register(struct snd_device *device);
29 static int snd_hwdep_dev_disconnect(struct snd_device *device);
30 
31 
snd_hwdep_search(struct snd_card * card,int device)32 static struct snd_hwdep *snd_hwdep_search(struct snd_card *card, int device)
33 {
34 	struct snd_hwdep *hwdep;
35 
36 	list_for_each_entry(hwdep, &snd_hwdep_devices, list)
37 		if (hwdep->card == card && hwdep->device == device)
38 			return hwdep;
39 	return NULL;
40 }
41 
snd_hwdep_llseek(struct file * file,loff_t offset,int orig)42 static loff_t snd_hwdep_llseek(struct file * file, loff_t offset, int orig)
43 {
44 	struct snd_hwdep *hw = file->private_data;
45 	if (hw->ops.llseek)
46 		return hw->ops.llseek(hw, file, offset, orig);
47 	return -ENXIO;
48 }
49 
snd_hwdep_read(struct file * file,char __user * buf,size_t count,loff_t * offset)50 static ssize_t snd_hwdep_read(struct file * file, char __user *buf,
51 			      size_t count, loff_t *offset)
52 {
53 	struct snd_hwdep *hw = file->private_data;
54 	if (hw->ops.read)
55 		return hw->ops.read(hw, buf, count, offset);
56 	return -ENXIO;
57 }
58 
snd_hwdep_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)59 static ssize_t snd_hwdep_write(struct file * file, const char __user *buf,
60 			       size_t count, loff_t *offset)
61 {
62 	struct snd_hwdep *hw = file->private_data;
63 	if (hw->ops.write)
64 		return hw->ops.write(hw, buf, count, offset);
65 	return -ENXIO;
66 }
67 
snd_hwdep_open(struct inode * inode,struct file * file)68 static int snd_hwdep_open(struct inode *inode, struct file * file)
69 {
70 	int major = imajor(inode);
71 	struct snd_hwdep *hw;
72 	int err;
73 	wait_queue_entry_t wait;
74 
75 	if (major == snd_major) {
76 		hw = snd_lookup_minor_data(iminor(inode),
77 					   SNDRV_DEVICE_TYPE_HWDEP);
78 #ifdef CONFIG_SND_OSSEMUL
79 	} else if (major == SOUND_MAJOR) {
80 		hw = snd_lookup_oss_minor_data(iminor(inode),
81 					       SNDRV_OSS_DEVICE_TYPE_DMFM);
82 #endif
83 	} else
84 		return -ENXIO;
85 	if (hw == NULL)
86 		return -ENODEV;
87 
88 	if (!try_module_get(hw->card->module)) {
89 		snd_card_unref(hw->card);
90 		return -EFAULT;
91 	}
92 
93 	init_waitqueue_entry(&wait, current);
94 	add_wait_queue(&hw->open_wait, &wait);
95 	mutex_lock(&hw->open_mutex);
96 	while (1) {
97 		if (hw->exclusive && hw->used > 0) {
98 			err = -EBUSY;
99 			break;
100 		}
101 		if (!hw->ops.open) {
102 			err = 0;
103 			break;
104 		}
105 		err = hw->ops.open(hw, file);
106 		if (err >= 0)
107 			break;
108 		if (err == -EAGAIN) {
109 			if (file->f_flags & O_NONBLOCK) {
110 				err = -EBUSY;
111 				break;
112 			}
113 		} else
114 			break;
115 		set_current_state(TASK_INTERRUPTIBLE);
116 		mutex_unlock(&hw->open_mutex);
117 		schedule();
118 		mutex_lock(&hw->open_mutex);
119 		if (hw->card->shutdown) {
120 			err = -ENODEV;
121 			break;
122 		}
123 		if (signal_pending(current)) {
124 			err = -ERESTARTSYS;
125 			break;
126 		}
127 	}
128 	remove_wait_queue(&hw->open_wait, &wait);
129 	if (err >= 0) {
130 		err = snd_card_file_add(hw->card, file);
131 		if (err >= 0) {
132 			file->private_data = hw;
133 			hw->used++;
134 		} else {
135 			if (hw->ops.release)
136 				hw->ops.release(hw, file);
137 		}
138 	}
139 	mutex_unlock(&hw->open_mutex);
140 	if (err < 0)
141 		module_put(hw->card->module);
142 	snd_card_unref(hw->card);
143 	return err;
144 }
145 
snd_hwdep_release(struct inode * inode,struct file * file)146 static int snd_hwdep_release(struct inode *inode, struct file * file)
147 {
148 	int err = 0;
149 	struct snd_hwdep *hw = file->private_data;
150 	struct module *mod = hw->card->module;
151 
152 	scoped_guard(mutex, &hw->open_mutex) {
153 		if (hw->ops.release)
154 			err = hw->ops.release(hw, file);
155 		if (hw->used > 0)
156 			hw->used--;
157 	}
158 	wake_up(&hw->open_wait);
159 
160 	snd_card_file_remove(hw->card, file);
161 	module_put(mod);
162 	return err;
163 }
164 
snd_hwdep_poll(struct file * file,poll_table * wait)165 static __poll_t snd_hwdep_poll(struct file * file, poll_table * wait)
166 {
167 	struct snd_hwdep *hw = file->private_data;
168 	if (hw->ops.poll)
169 		return hw->ops.poll(hw, file, wait);
170 	return 0;
171 }
172 
snd_hwdep_info(struct snd_hwdep * hw,struct snd_hwdep_info __user * _info)173 static int snd_hwdep_info(struct snd_hwdep *hw,
174 			  struct snd_hwdep_info __user *_info)
175 {
176 	struct snd_hwdep_info info;
177 
178 	memset(&info, 0, sizeof(info));
179 	info.card = hw->card->number;
180 	strscpy(info.id, hw->id, sizeof(info.id));
181 	strscpy(info.name, hw->name, sizeof(info.name));
182 	info.iface = hw->iface;
183 	if (copy_to_user(_info, &info, sizeof(info)))
184 		return -EFAULT;
185 	return 0;
186 }
187 
snd_hwdep_dsp_status(struct snd_hwdep * hw,struct snd_hwdep_dsp_status __user * _info)188 static int snd_hwdep_dsp_status(struct snd_hwdep *hw,
189 				struct snd_hwdep_dsp_status __user *_info)
190 {
191 	struct snd_hwdep_dsp_status info;
192 	int err;
193 
194 	if (! hw->ops.dsp_status)
195 		return -ENXIO;
196 	memset(&info, 0, sizeof(info));
197 	info.dsp_loaded = hw->dsp_loaded;
198 	err = hw->ops.dsp_status(hw, &info);
199 	if (err < 0)
200 		return err;
201 	if (copy_to_user(_info, &info, sizeof(info)))
202 		return -EFAULT;
203 	return 0;
204 }
205 
snd_hwdep_dsp_load(struct snd_hwdep * hw,struct snd_hwdep_dsp_image * info)206 static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
207 			      struct snd_hwdep_dsp_image *info)
208 {
209 	int err;
210 
211 	if (! hw->ops.dsp_load)
212 		return -ENXIO;
213 	if (info->index >= 32)
214 		return -EINVAL;
215 	/* check whether the dsp was already loaded */
216 	if (hw->dsp_loaded & (1u << info->index))
217 		return -EBUSY;
218 	err = hw->ops.dsp_load(hw, info);
219 	if (err < 0)
220 		return err;
221 	hw->dsp_loaded |= (1u << info->index);
222 	return 0;
223 }
224 
snd_hwdep_dsp_load_user(struct snd_hwdep * hw,struct snd_hwdep_dsp_image __user * _info)225 static int snd_hwdep_dsp_load_user(struct snd_hwdep *hw,
226 				   struct snd_hwdep_dsp_image __user *_info)
227 {
228 	struct snd_hwdep_dsp_image info = {};
229 
230 	if (copy_from_user(&info, _info, sizeof(info)))
231 		return -EFAULT;
232 	return snd_hwdep_dsp_load(hw, &info);
233 }
234 
235 
snd_hwdep_ioctl(struct file * file,unsigned int cmd,unsigned long arg)236 static long snd_hwdep_ioctl(struct file * file, unsigned int cmd,
237 			    unsigned long arg)
238 {
239 	struct snd_hwdep *hw = file->private_data;
240 	void __user *argp = (void __user *)arg;
241 	switch (cmd) {
242 	case SNDRV_HWDEP_IOCTL_PVERSION:
243 		return put_user(SNDRV_HWDEP_VERSION, (int __user *)argp);
244 	case SNDRV_HWDEP_IOCTL_INFO:
245 		return snd_hwdep_info(hw, argp);
246 	case SNDRV_HWDEP_IOCTL_DSP_STATUS:
247 		return snd_hwdep_dsp_status(hw, argp);
248 	case SNDRV_HWDEP_IOCTL_DSP_LOAD:
249 		return snd_hwdep_dsp_load_user(hw, argp);
250 	}
251 	if (hw->ops.ioctl)
252 		return hw->ops.ioctl(hw, file, cmd, arg);
253 	return -ENOTTY;
254 }
255 
snd_hwdep_mmap(struct file * file,struct vm_area_struct * vma)256 static int snd_hwdep_mmap(struct file * file, struct vm_area_struct * vma)
257 {
258 	struct snd_hwdep *hw = file->private_data;
259 	if (hw->ops.mmap)
260 		return hw->ops.mmap(hw, file, vma);
261 	return -ENXIO;
262 }
263 
snd_hwdep_control_ioctl(struct snd_card * card,struct snd_ctl_file * control,unsigned int cmd,unsigned long arg)264 static int snd_hwdep_control_ioctl(struct snd_card *card,
265 				   struct snd_ctl_file * control,
266 				   unsigned int cmd, unsigned long arg)
267 {
268 	switch (cmd) {
269 	case SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE:
270 		{
271 			int device;
272 
273 			if (get_user(device, (int __user *)arg))
274 				return -EFAULT;
275 
276 			scoped_guard(mutex, &register_mutex) {
277 				if (device < 0)
278 					device = 0;
279 				else if (device < SNDRV_MINOR_HWDEPS)
280 					device++;
281 				else
282 					device = SNDRV_MINOR_HWDEPS;
283 
284 				while (device < SNDRV_MINOR_HWDEPS) {
285 					if (snd_hwdep_search(card, device))
286 						break;
287 					device++;
288 				}
289 				if (device >= SNDRV_MINOR_HWDEPS)
290 					device = -1;
291 			}
292 			if (put_user(device, (int __user *)arg))
293 				return -EFAULT;
294 			return 0;
295 		}
296 	case SNDRV_CTL_IOCTL_HWDEP_INFO:
297 		{
298 			struct snd_hwdep_info __user *info = (struct snd_hwdep_info __user *)arg;
299 			int device;
300 			struct snd_hwdep *hwdep;
301 
302 			if (get_user(device, &info->device))
303 				return -EFAULT;
304 			scoped_guard(mutex, &register_mutex) {
305 				hwdep = snd_hwdep_search(card, device);
306 				if (!hwdep)
307 					return -ENXIO;
308 				return snd_hwdep_info(hwdep, info);
309 			}
310 			break;
311 		}
312 	}
313 	return -ENOIOCTLCMD;
314 }
315 
316 #ifdef CONFIG_COMPAT
317 #include "hwdep_compat.c"
318 #else
319 #define snd_hwdep_ioctl_compat	NULL
320 #endif
321 
322 /*
323 
324  */
325 
326 static const struct file_operations snd_hwdep_f_ops =
327 {
328 	.owner = 	THIS_MODULE,
329 	.llseek =	snd_hwdep_llseek,
330 	.read = 	snd_hwdep_read,
331 	.write =	snd_hwdep_write,
332 	.open =		snd_hwdep_open,
333 	.release =	snd_hwdep_release,
334 	.poll =		snd_hwdep_poll,
335 	.unlocked_ioctl =	snd_hwdep_ioctl,
336 	.compat_ioctl =	snd_hwdep_ioctl_compat,
337 	.mmap =		snd_hwdep_mmap,
338 };
339 
snd_hwdep_free(struct snd_hwdep * hwdep)340 static void snd_hwdep_free(struct snd_hwdep *hwdep)
341 {
342 	if (!hwdep)
343 		return;
344 	if (hwdep->private_free)
345 		hwdep->private_free(hwdep);
346 	put_device(hwdep->dev);
347 	kfree(hwdep);
348 }
349 
350 /**
351  * snd_hwdep_new - create a new hwdep instance
352  * @card: the card instance
353  * @id: the id string
354  * @device: the device index (zero-based)
355  * @rhwdep: the pointer to store the new hwdep instance
356  *
357  * Creates a new hwdep instance with the given index on the card.
358  * The callbacks (hwdep->ops) must be set on the returned instance
359  * after this call manually by the caller.
360  *
361  * Return: Zero if successful, or a negative error code on failure.
362  */
snd_hwdep_new(struct snd_card * card,char * id,int device,struct snd_hwdep ** rhwdep)363 int snd_hwdep_new(struct snd_card *card, char *id, int device,
364 		  struct snd_hwdep **rhwdep)
365 {
366 	struct snd_hwdep *hwdep;
367 	int err;
368 	static const struct snd_device_ops ops = {
369 		.dev_free = snd_hwdep_dev_free,
370 		.dev_register = snd_hwdep_dev_register,
371 		.dev_disconnect = snd_hwdep_dev_disconnect,
372 	};
373 
374 	if (snd_BUG_ON(!card))
375 		return -ENXIO;
376 	if (rhwdep)
377 		*rhwdep = NULL;
378 	hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
379 	if (!hwdep)
380 		return -ENOMEM;
381 
382 	init_waitqueue_head(&hwdep->open_wait);
383 	mutex_init(&hwdep->open_mutex);
384 	hwdep->card = card;
385 	hwdep->device = device;
386 	if (id)
387 		strscpy(hwdep->id, id, sizeof(hwdep->id));
388 
389 	err = snd_device_alloc(&hwdep->dev, card);
390 	if (err < 0) {
391 		snd_hwdep_free(hwdep);
392 		return err;
393 	}
394 
395 	dev_set_name(hwdep->dev, "hwC%iD%i", card->number, device);
396 #ifdef CONFIG_SND_OSSEMUL
397 	hwdep->oss_type = -1;
398 #endif
399 
400 	err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops);
401 	if (err < 0) {
402 		snd_hwdep_free(hwdep);
403 		return err;
404 	}
405 
406 	if (rhwdep)
407 		*rhwdep = hwdep;
408 	return 0;
409 }
410 EXPORT_SYMBOL(snd_hwdep_new);
411 
snd_hwdep_dev_free(struct snd_device * device)412 static int snd_hwdep_dev_free(struct snd_device *device)
413 {
414 	snd_hwdep_free(device->device_data);
415 	return 0;
416 }
417 
snd_hwdep_dev_register(struct snd_device * device)418 static int snd_hwdep_dev_register(struct snd_device *device)
419 {
420 	struct snd_hwdep *hwdep = device->device_data;
421 	struct snd_card *card = hwdep->card;
422 	int err;
423 
424 	guard(mutex)(&register_mutex);
425 	if (snd_hwdep_search(card, hwdep->device))
426 		return -EBUSY;
427 	list_add_tail(&hwdep->list, &snd_hwdep_devices);
428 	err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
429 				  hwdep->card, hwdep->device,
430 				  &snd_hwdep_f_ops, hwdep, hwdep->dev);
431 	if (err < 0) {
432 		dev_err(hwdep->dev, "unable to register\n");
433 		list_del(&hwdep->list);
434 		return err;
435 	}
436 
437 #ifdef CONFIG_SND_OSSEMUL
438 	hwdep->ossreg = 0;
439 	if (hwdep->oss_type >= 0) {
440 		if (hwdep->oss_type == SNDRV_OSS_DEVICE_TYPE_DMFM &&
441 		    hwdep->device)
442 			dev_warn(hwdep->dev,
443 				 "only hwdep device 0 can be registered as OSS direct FM device!\n");
444 		else if (snd_register_oss_device(hwdep->oss_type,
445 						 card, hwdep->device,
446 						 &snd_hwdep_f_ops, hwdep) < 0)
447 			dev_warn(hwdep->dev,
448 				 "unable to register OSS compatibility device\n");
449 		else
450 			hwdep->ossreg = 1;
451 	}
452 #endif
453 	return 0;
454 }
455 
snd_hwdep_dev_disconnect(struct snd_device * device)456 static int snd_hwdep_dev_disconnect(struct snd_device *device)
457 {
458 	struct snd_hwdep *hwdep = device->device_data;
459 
460 	if (snd_BUG_ON(!hwdep))
461 		return -ENXIO;
462 	guard(mutex)(&register_mutex);
463 	if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep)
464 		return -EINVAL;
465 	guard(mutex)(&hwdep->open_mutex);
466 	wake_up(&hwdep->open_wait);
467 #ifdef CONFIG_SND_OSSEMUL
468 	if (hwdep->ossreg)
469 		snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
470 #endif
471 	snd_unregister_device(hwdep->dev);
472 	list_del_init(&hwdep->list);
473 	return 0;
474 }
475 
476 #ifdef CONFIG_SND_PROC_FS
477 /*
478  *  Info interface
479  */
480 
snd_hwdep_proc_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)481 static void snd_hwdep_proc_read(struct snd_info_entry *entry,
482 				struct snd_info_buffer *buffer)
483 {
484 	struct snd_hwdep *hwdep;
485 
486 	guard(mutex)(&register_mutex);
487 	list_for_each_entry(hwdep, &snd_hwdep_devices, list)
488 		snd_iprintf(buffer, "%02i-%02i: %s\n",
489 			    hwdep->card->number, hwdep->device, hwdep->name);
490 }
491 
492 static struct snd_info_entry *snd_hwdep_proc_entry;
493 
snd_hwdep_proc_init(void)494 static void __init snd_hwdep_proc_init(void)
495 {
496 	struct snd_info_entry *entry;
497 
498 	entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL);
499 	if (entry) {
500 		entry->c.text.read = snd_hwdep_proc_read;
501 		if (snd_info_register(entry) < 0) {
502 			snd_info_free_entry(entry);
503 			entry = NULL;
504 		}
505 	}
506 	snd_hwdep_proc_entry = entry;
507 }
508 
snd_hwdep_proc_done(void)509 static void __exit snd_hwdep_proc_done(void)
510 {
511 	snd_info_free_entry(snd_hwdep_proc_entry);
512 }
513 #else /* !CONFIG_SND_PROC_FS */
514 #define snd_hwdep_proc_init()
515 #define snd_hwdep_proc_done()
516 #endif /* CONFIG_SND_PROC_FS */
517 
518 
519 /*
520  *  ENTRY functions
521  */
522 
alsa_hwdep_init(void)523 static int __init alsa_hwdep_init(void)
524 {
525 	snd_hwdep_proc_init();
526 	snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
527 	snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
528 	return 0;
529 }
530 
alsa_hwdep_exit(void)531 static void __exit alsa_hwdep_exit(void)
532 {
533 	snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
534 	snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
535 	snd_hwdep_proc_done();
536 }
537 
538 module_init(alsa_hwdep_init)
539 module_exit(alsa_hwdep_exit)
540