xref: /openbmc/linux/sound/core/hwdep.c (revision 9b93eb47)
1 /*
2  *  Hardware dependent layer
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/major.h>
23 #include <linux/init.h>
24 #include <linux/slab.h>
25 #include <linux/time.h>
26 #include <linux/mutex.h>
27 #include <linux/module.h>
28 #include <linux/sched/signal.h>
29 #include <sound/core.h>
30 #include <sound/control.h>
31 #include <sound/minors.h>
32 #include <sound/hwdep.h>
33 #include <sound/info.h>
34 
35 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
36 MODULE_DESCRIPTION("Hardware dependent layer");
37 MODULE_LICENSE("GPL");
38 
39 static LIST_HEAD(snd_hwdep_devices);
40 static DEFINE_MUTEX(register_mutex);
41 
42 static int snd_hwdep_dev_free(struct snd_device *device);
43 static int snd_hwdep_dev_register(struct snd_device *device);
44 static int snd_hwdep_dev_disconnect(struct snd_device *device);
45 
46 
47 static struct snd_hwdep *snd_hwdep_search(struct snd_card *card, int device)
48 {
49 	struct snd_hwdep *hwdep;
50 
51 	list_for_each_entry(hwdep, &snd_hwdep_devices, list)
52 		if (hwdep->card == card && hwdep->device == device)
53 			return hwdep;
54 	return NULL;
55 }
56 
57 static loff_t snd_hwdep_llseek(struct file * file, loff_t offset, int orig)
58 {
59 	struct snd_hwdep *hw = file->private_data;
60 	if (hw->ops.llseek)
61 		return hw->ops.llseek(hw, file, offset, orig);
62 	return -ENXIO;
63 }
64 
65 static ssize_t snd_hwdep_read(struct file * file, char __user *buf,
66 			      size_t count, loff_t *offset)
67 {
68 	struct snd_hwdep *hw = file->private_data;
69 	if (hw->ops.read)
70 		return hw->ops.read(hw, buf, count, offset);
71 	return -ENXIO;
72 }
73 
74 static ssize_t snd_hwdep_write(struct file * file, const char __user *buf,
75 			       size_t count, loff_t *offset)
76 {
77 	struct snd_hwdep *hw = file->private_data;
78 	if (hw->ops.write)
79 		return hw->ops.write(hw, buf, count, offset);
80 	return -ENXIO;
81 }
82 
83 static int snd_hwdep_open(struct inode *inode, struct file * file)
84 {
85 	int major = imajor(inode);
86 	struct snd_hwdep *hw;
87 	int err;
88 	wait_queue_entry_t wait;
89 
90 	if (major == snd_major) {
91 		hw = snd_lookup_minor_data(iminor(inode),
92 					   SNDRV_DEVICE_TYPE_HWDEP);
93 #ifdef CONFIG_SND_OSSEMUL
94 	} else if (major == SOUND_MAJOR) {
95 		hw = snd_lookup_oss_minor_data(iminor(inode),
96 					       SNDRV_OSS_DEVICE_TYPE_DMFM);
97 #endif
98 	} else
99 		return -ENXIO;
100 	if (hw == NULL)
101 		return -ENODEV;
102 
103 	if (!try_module_get(hw->card->module)) {
104 		snd_card_unref(hw->card);
105 		return -EFAULT;
106 	}
107 
108 	init_waitqueue_entry(&wait, current);
109 	add_wait_queue(&hw->open_wait, &wait);
110 	mutex_lock(&hw->open_mutex);
111 	while (1) {
112 		if (hw->exclusive && hw->used > 0) {
113 			err = -EBUSY;
114 			break;
115 		}
116 		if (!hw->ops.open) {
117 			err = 0;
118 			break;
119 		}
120 		err = hw->ops.open(hw, file);
121 		if (err >= 0)
122 			break;
123 		if (err == -EAGAIN) {
124 			if (file->f_flags & O_NONBLOCK) {
125 				err = -EBUSY;
126 				break;
127 			}
128 		} else
129 			break;
130 		set_current_state(TASK_INTERRUPTIBLE);
131 		mutex_unlock(&hw->open_mutex);
132 		schedule();
133 		mutex_lock(&hw->open_mutex);
134 		if (hw->card->shutdown) {
135 			err = -ENODEV;
136 			break;
137 		}
138 		if (signal_pending(current)) {
139 			err = -ERESTARTSYS;
140 			break;
141 		}
142 	}
143 	remove_wait_queue(&hw->open_wait, &wait);
144 	if (err >= 0) {
145 		err = snd_card_file_add(hw->card, file);
146 		if (err >= 0) {
147 			file->private_data = hw;
148 			hw->used++;
149 		} else {
150 			if (hw->ops.release)
151 				hw->ops.release(hw, file);
152 		}
153 	}
154 	mutex_unlock(&hw->open_mutex);
155 	if (err < 0)
156 		module_put(hw->card->module);
157 	snd_card_unref(hw->card);
158 	return err;
159 }
160 
161 static int snd_hwdep_release(struct inode *inode, struct file * file)
162 {
163 	int err = 0;
164 	struct snd_hwdep *hw = file->private_data;
165 	struct module *mod = hw->card->module;
166 
167 	mutex_lock(&hw->open_mutex);
168 	if (hw->ops.release)
169 		err = hw->ops.release(hw, file);
170 	if (hw->used > 0)
171 		hw->used--;
172 	mutex_unlock(&hw->open_mutex);
173 	wake_up(&hw->open_wait);
174 
175 	snd_card_file_remove(hw->card, file);
176 	module_put(mod);
177 	return err;
178 }
179 
180 static __poll_t snd_hwdep_poll(struct file * file, poll_table * wait)
181 {
182 	struct snd_hwdep *hw = file->private_data;
183 	if (hw->ops.poll)
184 		return hw->ops.poll(hw, file, wait);
185 	return 0;
186 }
187 
188 static int snd_hwdep_info(struct snd_hwdep *hw,
189 			  struct snd_hwdep_info __user *_info)
190 {
191 	struct snd_hwdep_info info;
192 
193 	memset(&info, 0, sizeof(info));
194 	info.card = hw->card->number;
195 	strlcpy(info.id, hw->id, sizeof(info.id));
196 	strlcpy(info.name, hw->name, sizeof(info.name));
197 	info.iface = hw->iface;
198 	if (copy_to_user(_info, &info, sizeof(info)))
199 		return -EFAULT;
200 	return 0;
201 }
202 
203 static int snd_hwdep_dsp_status(struct snd_hwdep *hw,
204 				struct snd_hwdep_dsp_status __user *_info)
205 {
206 	struct snd_hwdep_dsp_status info;
207 	int err;
208 
209 	if (! hw->ops.dsp_status)
210 		return -ENXIO;
211 	memset(&info, 0, sizeof(info));
212 	info.dsp_loaded = hw->dsp_loaded;
213 	if ((err = hw->ops.dsp_status(hw, &info)) < 0)
214 		return err;
215 	if (copy_to_user(_info, &info, sizeof(info)))
216 		return -EFAULT;
217 	return 0;
218 }
219 
220 static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
221 			      struct snd_hwdep_dsp_image __user *_info)
222 {
223 	struct snd_hwdep_dsp_image info;
224 	int err;
225 
226 	if (! hw->ops.dsp_load)
227 		return -ENXIO;
228 	memset(&info, 0, sizeof(info));
229 	if (copy_from_user(&info, _info, sizeof(info)))
230 		return -EFAULT;
231 	if (info.index >= 32)
232 		return -EINVAL;
233 	/* check whether the dsp was already loaded */
234 	if (hw->dsp_loaded & (1 << info.index))
235 		return -EBUSY;
236 	err = hw->ops.dsp_load(hw, &info);
237 	if (err < 0)
238 		return err;
239 	hw->dsp_loaded |= (1 << info.index);
240 	return 0;
241 }
242 
243 static long snd_hwdep_ioctl(struct file * file, unsigned int cmd,
244 			    unsigned long arg)
245 {
246 	struct snd_hwdep *hw = file->private_data;
247 	void __user *argp = (void __user *)arg;
248 	switch (cmd) {
249 	case SNDRV_HWDEP_IOCTL_PVERSION:
250 		return put_user(SNDRV_HWDEP_VERSION, (int __user *)argp);
251 	case SNDRV_HWDEP_IOCTL_INFO:
252 		return snd_hwdep_info(hw, argp);
253 	case SNDRV_HWDEP_IOCTL_DSP_STATUS:
254 		return snd_hwdep_dsp_status(hw, argp);
255 	case SNDRV_HWDEP_IOCTL_DSP_LOAD:
256 		return snd_hwdep_dsp_load(hw, argp);
257 	}
258 	if (hw->ops.ioctl)
259 		return hw->ops.ioctl(hw, file, cmd, arg);
260 	return -ENOTTY;
261 }
262 
263 static int snd_hwdep_mmap(struct file * file, struct vm_area_struct * vma)
264 {
265 	struct snd_hwdep *hw = file->private_data;
266 	if (hw->ops.mmap)
267 		return hw->ops.mmap(hw, file, vma);
268 	return -ENXIO;
269 }
270 
271 static int snd_hwdep_control_ioctl(struct snd_card *card,
272 				   struct snd_ctl_file * control,
273 				   unsigned int cmd, unsigned long arg)
274 {
275 	switch (cmd) {
276 	case SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE:
277 		{
278 			int device;
279 
280 			if (get_user(device, (int __user *)arg))
281 				return -EFAULT;
282 			mutex_lock(&register_mutex);
283 
284 			if (device < 0)
285 				device = 0;
286 			else if (device < SNDRV_MINOR_HWDEPS)
287 				device++;
288 			else
289 				device = SNDRV_MINOR_HWDEPS;
290 
291 			while (device < SNDRV_MINOR_HWDEPS) {
292 				if (snd_hwdep_search(card, device))
293 					break;
294 				device++;
295 			}
296 			if (device >= SNDRV_MINOR_HWDEPS)
297 				device = -1;
298 			mutex_unlock(&register_mutex);
299 			if (put_user(device, (int __user *)arg))
300 				return -EFAULT;
301 			return 0;
302 		}
303 	case SNDRV_CTL_IOCTL_HWDEP_INFO:
304 		{
305 			struct snd_hwdep_info __user *info = (struct snd_hwdep_info __user *)arg;
306 			int device, err;
307 			struct snd_hwdep *hwdep;
308 
309 			if (get_user(device, &info->device))
310 				return -EFAULT;
311 			mutex_lock(&register_mutex);
312 			hwdep = snd_hwdep_search(card, device);
313 			if (hwdep)
314 				err = snd_hwdep_info(hwdep, info);
315 			else
316 				err = -ENXIO;
317 			mutex_unlock(&register_mutex);
318 			return err;
319 		}
320 	}
321 	return -ENOIOCTLCMD;
322 }
323 
324 #ifdef CONFIG_COMPAT
325 #include "hwdep_compat.c"
326 #else
327 #define snd_hwdep_ioctl_compat	NULL
328 #endif
329 
330 /*
331 
332  */
333 
334 static const struct file_operations snd_hwdep_f_ops =
335 {
336 	.owner = 	THIS_MODULE,
337 	.llseek =	snd_hwdep_llseek,
338 	.read = 	snd_hwdep_read,
339 	.write =	snd_hwdep_write,
340 	.open =		snd_hwdep_open,
341 	.release =	snd_hwdep_release,
342 	.poll =		snd_hwdep_poll,
343 	.unlocked_ioctl =	snd_hwdep_ioctl,
344 	.compat_ioctl =	snd_hwdep_ioctl_compat,
345 	.mmap =		snd_hwdep_mmap,
346 };
347 
348 static void release_hwdep_device(struct device *dev)
349 {
350 	kfree(container_of(dev, struct snd_hwdep, dev));
351 }
352 
353 /**
354  * snd_hwdep_new - create a new hwdep instance
355  * @card: the card instance
356  * @id: the id string
357  * @device: the device index (zero-based)
358  * @rhwdep: the pointer to store the new hwdep instance
359  *
360  * Creates a new hwdep instance with the given index on the card.
361  * The callbacks (hwdep->ops) must be set on the returned instance
362  * after this call manually by the caller.
363  *
364  * Return: Zero if successful, or a negative error code on failure.
365  */
366 int snd_hwdep_new(struct snd_card *card, char *id, int device,
367 		  struct snd_hwdep **rhwdep)
368 {
369 	struct snd_hwdep *hwdep;
370 	int err;
371 	static struct snd_device_ops ops = {
372 		.dev_free = snd_hwdep_dev_free,
373 		.dev_register = snd_hwdep_dev_register,
374 		.dev_disconnect = snd_hwdep_dev_disconnect,
375 	};
376 
377 	if (snd_BUG_ON(!card))
378 		return -ENXIO;
379 	if (rhwdep)
380 		*rhwdep = NULL;
381 	hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
382 	if (!hwdep)
383 		return -ENOMEM;
384 
385 	init_waitqueue_head(&hwdep->open_wait);
386 	mutex_init(&hwdep->open_mutex);
387 	hwdep->card = card;
388 	hwdep->device = device;
389 	if (id)
390 		strlcpy(hwdep->id, id, sizeof(hwdep->id));
391 
392 	snd_device_initialize(&hwdep->dev, card);
393 	hwdep->dev.release = release_hwdep_device;
394 	dev_set_name(&hwdep->dev, "hwC%iD%i", card->number, device);
395 #ifdef CONFIG_SND_OSSEMUL
396 	hwdep->oss_type = -1;
397 #endif
398 
399 	err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops);
400 	if (err < 0) {
401 		put_device(&hwdep->dev);
402 		return err;
403 	}
404 
405 	if (rhwdep)
406 		*rhwdep = hwdep;
407 	return 0;
408 }
409 EXPORT_SYMBOL(snd_hwdep_new);
410 
411 static int snd_hwdep_dev_free(struct snd_device *device)
412 {
413 	struct snd_hwdep *hwdep = device->device_data;
414 	if (!hwdep)
415 		return 0;
416 	if (hwdep->private_free)
417 		hwdep->private_free(hwdep);
418 	put_device(&hwdep->dev);
419 	return 0;
420 }
421 
422 static int snd_hwdep_dev_register(struct snd_device *device)
423 {
424 	struct snd_hwdep *hwdep = device->device_data;
425 	struct snd_card *card = hwdep->card;
426 	int err;
427 
428 	mutex_lock(&register_mutex);
429 	if (snd_hwdep_search(card, hwdep->device)) {
430 		mutex_unlock(&register_mutex);
431 		return -EBUSY;
432 	}
433 	list_add_tail(&hwdep->list, &snd_hwdep_devices);
434 	err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
435 				  hwdep->card, hwdep->device,
436 				  &snd_hwdep_f_ops, hwdep, &hwdep->dev);
437 	if (err < 0) {
438 		dev_err(&hwdep->dev, "unable to register\n");
439 		list_del(&hwdep->list);
440 		mutex_unlock(&register_mutex);
441 		return err;
442 	}
443 
444 #ifdef CONFIG_SND_OSSEMUL
445 	hwdep->ossreg = 0;
446 	if (hwdep->oss_type >= 0) {
447 		if (hwdep->oss_type == SNDRV_OSS_DEVICE_TYPE_DMFM &&
448 		    hwdep->device)
449 			dev_warn(&hwdep->dev,
450 				 "only hwdep device 0 can be registered as OSS direct FM device!\n");
451 		else if (snd_register_oss_device(hwdep->oss_type,
452 						 card, hwdep->device,
453 						 &snd_hwdep_f_ops, hwdep) < 0)
454 			dev_warn(&hwdep->dev,
455 				 "unable to register OSS compatibility device\n");
456 		else
457 			hwdep->ossreg = 1;
458 	}
459 #endif
460 	mutex_unlock(&register_mutex);
461 	return 0;
462 }
463 
464 static int snd_hwdep_dev_disconnect(struct snd_device *device)
465 {
466 	struct snd_hwdep *hwdep = device->device_data;
467 
468 	if (snd_BUG_ON(!hwdep))
469 		return -ENXIO;
470 	mutex_lock(&register_mutex);
471 	if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {
472 		mutex_unlock(&register_mutex);
473 		return -EINVAL;
474 	}
475 	mutex_lock(&hwdep->open_mutex);
476 	wake_up(&hwdep->open_wait);
477 #ifdef CONFIG_SND_OSSEMUL
478 	if (hwdep->ossreg)
479 		snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
480 #endif
481 	snd_unregister_device(&hwdep->dev);
482 	list_del_init(&hwdep->list);
483 	mutex_unlock(&hwdep->open_mutex);
484 	mutex_unlock(&register_mutex);
485 	return 0;
486 }
487 
488 #ifdef CONFIG_SND_PROC_FS
489 /*
490  *  Info interface
491  */
492 
493 static void snd_hwdep_proc_read(struct snd_info_entry *entry,
494 				struct snd_info_buffer *buffer)
495 {
496 	struct snd_hwdep *hwdep;
497 
498 	mutex_lock(&register_mutex);
499 	list_for_each_entry(hwdep, &snd_hwdep_devices, list)
500 		snd_iprintf(buffer, "%02i-%02i: %s\n",
501 			    hwdep->card->number, hwdep->device, hwdep->name);
502 	mutex_unlock(&register_mutex);
503 }
504 
505 static struct snd_info_entry *snd_hwdep_proc_entry;
506 
507 static void __init snd_hwdep_proc_init(void)
508 {
509 	struct snd_info_entry *entry;
510 
511 	if ((entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL)) != NULL) {
512 		entry->c.text.read = snd_hwdep_proc_read;
513 		if (snd_info_register(entry) < 0) {
514 			snd_info_free_entry(entry);
515 			entry = NULL;
516 		}
517 	}
518 	snd_hwdep_proc_entry = entry;
519 }
520 
521 static void __exit snd_hwdep_proc_done(void)
522 {
523 	snd_info_free_entry(snd_hwdep_proc_entry);
524 }
525 #else /* !CONFIG_SND_PROC_FS */
526 #define snd_hwdep_proc_init()
527 #define snd_hwdep_proc_done()
528 #endif /* CONFIG_SND_PROC_FS */
529 
530 
531 /*
532  *  ENTRY functions
533  */
534 
535 static int __init alsa_hwdep_init(void)
536 {
537 	snd_hwdep_proc_init();
538 	snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
539 	snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
540 	return 0;
541 }
542 
543 static void __exit alsa_hwdep_exit(void)
544 {
545 	snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
546 	snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
547 	snd_hwdep_proc_done();
548 }
549 
550 module_init(alsa_hwdep_init)
551 module_exit(alsa_hwdep_exit)
552