xref: /openbmc/linux/sound/core/hwdep.c (revision d5e7cafd)
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 <sound/core.h>
29 #include <sound/control.h>
30 #include <sound/minors.h>
31 #include <sound/hwdep.h>
32 #include <sound/info.h>
33 
34 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
35 MODULE_DESCRIPTION("Hardware dependent layer");
36 MODULE_LICENSE("GPL");
37 
38 static LIST_HEAD(snd_hwdep_devices);
39 static DEFINE_MUTEX(register_mutex);
40 
41 static int snd_hwdep_dev_free(struct snd_device *device);
42 static int snd_hwdep_dev_register(struct snd_device *device);
43 static int snd_hwdep_dev_disconnect(struct snd_device *device);
44 
45 
46 static struct snd_hwdep *snd_hwdep_search(struct snd_card *card, int device)
47 {
48 	struct snd_hwdep *hwdep;
49 
50 	list_for_each_entry(hwdep, &snd_hwdep_devices, list)
51 		if (hwdep->card == card && hwdep->device == device)
52 			return hwdep;
53 	return NULL;
54 }
55 
56 static loff_t snd_hwdep_llseek(struct file * file, loff_t offset, int orig)
57 {
58 	struct snd_hwdep *hw = file->private_data;
59 	if (hw->ops.llseek)
60 		return hw->ops.llseek(hw, file, offset, orig);
61 	return -ENXIO;
62 }
63 
64 static ssize_t snd_hwdep_read(struct file * file, char __user *buf,
65 			      size_t count, loff_t *offset)
66 {
67 	struct snd_hwdep *hw = file->private_data;
68 	if (hw->ops.read)
69 		return hw->ops.read(hw, buf, count, offset);
70 	return -ENXIO;
71 }
72 
73 static ssize_t snd_hwdep_write(struct file * file, const char __user *buf,
74 			       size_t count, loff_t *offset)
75 {
76 	struct snd_hwdep *hw = file->private_data;
77 	if (hw->ops.write)
78 		return hw->ops.write(hw, buf, count, offset);
79 	return -ENXIO;
80 }
81 
82 static int snd_hwdep_open(struct inode *inode, struct file * file)
83 {
84 	int major = imajor(inode);
85 	struct snd_hwdep *hw;
86 	int err;
87 	wait_queue_t wait;
88 
89 	if (major == snd_major) {
90 		hw = snd_lookup_minor_data(iminor(inode),
91 					   SNDRV_DEVICE_TYPE_HWDEP);
92 #ifdef CONFIG_SND_OSSEMUL
93 	} else if (major == SOUND_MAJOR) {
94 		hw = snd_lookup_oss_minor_data(iminor(inode),
95 					       SNDRV_OSS_DEVICE_TYPE_DMFM);
96 #endif
97 	} else
98 		return -ENXIO;
99 	if (hw == NULL)
100 		return -ENODEV;
101 
102 	if (!try_module_get(hw->card->module)) {
103 		snd_card_unref(hw->card);
104 		return -EFAULT;
105 	}
106 
107 	init_waitqueue_entry(&wait, current);
108 	add_wait_queue(&hw->open_wait, &wait);
109 	mutex_lock(&hw->open_mutex);
110 	while (1) {
111 		if (hw->exclusive && hw->used > 0) {
112 			err = -EBUSY;
113 			break;
114 		}
115 		if (!hw->ops.open) {
116 			err = 0;
117 			break;
118 		}
119 		err = hw->ops.open(hw, file);
120 		if (err >= 0)
121 			break;
122 		if (err == -EAGAIN) {
123 			if (file->f_flags & O_NONBLOCK) {
124 				err = -EBUSY;
125 				break;
126 			}
127 		} else
128 			break;
129 		set_current_state(TASK_INTERRUPTIBLE);
130 		mutex_unlock(&hw->open_mutex);
131 		schedule();
132 		mutex_lock(&hw->open_mutex);
133 		if (hw->card->shutdown) {
134 			err = -ENODEV;
135 			break;
136 		}
137 		if (signal_pending(current)) {
138 			err = -ERESTARTSYS;
139 			break;
140 		}
141 	}
142 	remove_wait_queue(&hw->open_wait, &wait);
143 	if (err >= 0) {
144 		err = snd_card_file_add(hw->card, file);
145 		if (err >= 0) {
146 			file->private_data = hw;
147 			hw->used++;
148 		} else {
149 			if (hw->ops.release)
150 				hw->ops.release(hw, file);
151 		}
152 	}
153 	mutex_unlock(&hw->open_mutex);
154 	if (err < 0)
155 		module_put(hw->card->module);
156 	snd_card_unref(hw->card);
157 	return err;
158 }
159 
160 static int snd_hwdep_release(struct inode *inode, struct file * file)
161 {
162 	int err = 0;
163 	struct snd_hwdep *hw = file->private_data;
164 	struct module *mod = hw->card->module;
165 
166 	mutex_lock(&hw->open_mutex);
167 	if (hw->ops.release)
168 		err = hw->ops.release(hw, file);
169 	if (hw->used > 0)
170 		hw->used--;
171 	mutex_unlock(&hw->open_mutex);
172 	wake_up(&hw->open_wait);
173 
174 	snd_card_file_remove(hw->card, file);
175 	module_put(mod);
176 	return err;
177 }
178 
179 static unsigned int snd_hwdep_poll(struct file * file, poll_table * wait)
180 {
181 	struct snd_hwdep *hw = file->private_data;
182 	if (hw->ops.poll)
183 		return hw->ops.poll(hw, file, wait);
184 	return 0;
185 }
186 
187 static int snd_hwdep_info(struct snd_hwdep *hw,
188 			  struct snd_hwdep_info __user *_info)
189 {
190 	struct snd_hwdep_info info;
191 
192 	memset(&info, 0, sizeof(info));
193 	info.card = hw->card->number;
194 	strlcpy(info.id, hw->id, sizeof(info.id));
195 	strlcpy(info.name, hw->name, sizeof(info.name));
196 	info.iface = hw->iface;
197 	if (copy_to_user(_info, &info, sizeof(info)))
198 		return -EFAULT;
199 	return 0;
200 }
201 
202 static int snd_hwdep_dsp_status(struct snd_hwdep *hw,
203 				struct snd_hwdep_dsp_status __user *_info)
204 {
205 	struct snd_hwdep_dsp_status info;
206 	int err;
207 
208 	if (! hw->ops.dsp_status)
209 		return -ENXIO;
210 	memset(&info, 0, sizeof(info));
211 	info.dsp_loaded = hw->dsp_loaded;
212 	if ((err = hw->ops.dsp_status(hw, &info)) < 0)
213 		return err;
214 	if (copy_to_user(_info, &info, sizeof(info)))
215 		return -EFAULT;
216 	return 0;
217 }
218 
219 static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
220 			      struct snd_hwdep_dsp_image __user *_info)
221 {
222 	struct snd_hwdep_dsp_image info;
223 	int err;
224 
225 	if (! hw->ops.dsp_load)
226 		return -ENXIO;
227 	memset(&info, 0, sizeof(info));
228 	if (copy_from_user(&info, _info, sizeof(info)))
229 		return -EFAULT;
230 	/* check whether the dsp was already loaded */
231 	if (hw->dsp_loaded & (1 << info.index))
232 		return -EBUSY;
233 	if (!access_ok(VERIFY_READ, info.image, info.length))
234 		return -EFAULT;
235 	err = hw->ops.dsp_load(hw, &info);
236 	if (err < 0)
237 		return err;
238 	hw->dsp_loaded |= (1 << info.index);
239 	return 0;
240 }
241 
242 static long snd_hwdep_ioctl(struct file * file, unsigned int cmd,
243 			    unsigned long arg)
244 {
245 	struct snd_hwdep *hw = file->private_data;
246 	void __user *argp = (void __user *)arg;
247 	switch (cmd) {
248 	case SNDRV_HWDEP_IOCTL_PVERSION:
249 		return put_user(SNDRV_HWDEP_VERSION, (int __user *)argp);
250 	case SNDRV_HWDEP_IOCTL_INFO:
251 		return snd_hwdep_info(hw, argp);
252 	case SNDRV_HWDEP_IOCTL_DSP_STATUS:
253 		return snd_hwdep_dsp_status(hw, argp);
254 	case SNDRV_HWDEP_IOCTL_DSP_LOAD:
255 		return snd_hwdep_dsp_load(hw, argp);
256 	}
257 	if (hw->ops.ioctl)
258 		return hw->ops.ioctl(hw, file, cmd, arg);
259 	return -ENOTTY;
260 }
261 
262 static int snd_hwdep_mmap(struct file * file, struct vm_area_struct * vma)
263 {
264 	struct snd_hwdep *hw = file->private_data;
265 	if (hw->ops.mmap)
266 		return hw->ops.mmap(hw, file, vma);
267 	return -ENXIO;
268 }
269 
270 static int snd_hwdep_control_ioctl(struct snd_card *card,
271 				   struct snd_ctl_file * control,
272 				   unsigned int cmd, unsigned long arg)
273 {
274 	switch (cmd) {
275 	case SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE:
276 		{
277 			int device;
278 
279 			if (get_user(device, (int __user *)arg))
280 				return -EFAULT;
281 			mutex_lock(&register_mutex);
282 
283 			if (device < 0)
284 				device = 0;
285 			else if (device < SNDRV_MINOR_HWDEPS)
286 				device++;
287 			else
288 				device = SNDRV_MINOR_HWDEPS;
289 
290 			while (device < SNDRV_MINOR_HWDEPS) {
291 				if (snd_hwdep_search(card, device))
292 					break;
293 				device++;
294 			}
295 			if (device >= SNDRV_MINOR_HWDEPS)
296 				device = -1;
297 			mutex_unlock(&register_mutex);
298 			if (put_user(device, (int __user *)arg))
299 				return -EFAULT;
300 			return 0;
301 		}
302 	case SNDRV_CTL_IOCTL_HWDEP_INFO:
303 		{
304 			struct snd_hwdep_info __user *info = (struct snd_hwdep_info __user *)arg;
305 			int device, err;
306 			struct snd_hwdep *hwdep;
307 
308 			if (get_user(device, &info->device))
309 				return -EFAULT;
310 			mutex_lock(&register_mutex);
311 			hwdep = snd_hwdep_search(card, device);
312 			if (hwdep)
313 				err = snd_hwdep_info(hwdep, info);
314 			else
315 				err = -ENXIO;
316 			mutex_unlock(&register_mutex);
317 			return err;
318 		}
319 	}
320 	return -ENOIOCTLCMD;
321 }
322 
323 #ifdef CONFIG_COMPAT
324 #include "hwdep_compat.c"
325 #else
326 #define snd_hwdep_ioctl_compat	NULL
327 #endif
328 
329 /*
330 
331  */
332 
333 static const struct file_operations snd_hwdep_f_ops =
334 {
335 	.owner = 	THIS_MODULE,
336 	.llseek =	snd_hwdep_llseek,
337 	.read = 	snd_hwdep_read,
338 	.write =	snd_hwdep_write,
339 	.open =		snd_hwdep_open,
340 	.release =	snd_hwdep_release,
341 	.poll =		snd_hwdep_poll,
342 	.unlocked_ioctl =	snd_hwdep_ioctl,
343 	.compat_ioctl =	snd_hwdep_ioctl_compat,
344 	.mmap =		snd_hwdep_mmap,
345 };
346 
347 static void release_hwdep_device(struct device *dev)
348 {
349 	kfree(container_of(dev, struct snd_hwdep, dev));
350 }
351 
352 /**
353  * snd_hwdep_new - create a new hwdep instance
354  * @card: the card instance
355  * @id: the id string
356  * @device: the device index (zero-based)
357  * @rhwdep: the pointer to store the new hwdep instance
358  *
359  * Creates a new hwdep instance with the given index on the card.
360  * The callbacks (hwdep->ops) must be set on the returned instance
361  * after this call manually by the caller.
362  *
363  * Return: Zero if successful, or a negative error code on failure.
364  */
365 int snd_hwdep_new(struct snd_card *card, char *id, int device,
366 		  struct snd_hwdep **rhwdep)
367 {
368 	struct snd_hwdep *hwdep;
369 	int err;
370 	static struct snd_device_ops ops = {
371 		.dev_free = snd_hwdep_dev_free,
372 		.dev_register = snd_hwdep_dev_register,
373 		.dev_disconnect = snd_hwdep_dev_disconnect,
374 	};
375 
376 	if (snd_BUG_ON(!card))
377 		return -ENXIO;
378 	if (rhwdep)
379 		*rhwdep = NULL;
380 	hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
381 	if (hwdep == NULL) {
382 		dev_err(card->dev, "hwdep: cannot allocate\n");
383 		return -ENOMEM;
384 	}
385 
386 	init_waitqueue_head(&hwdep->open_wait);
387 	mutex_init(&hwdep->open_mutex);
388 	hwdep->card = card;
389 	hwdep->device = device;
390 	if (id)
391 		strlcpy(hwdep->id, id, sizeof(hwdep->id));
392 
393 	snd_device_initialize(&hwdep->dev, card);
394 	hwdep->dev.release = release_hwdep_device;
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 		put_device(&hwdep->dev);
403 		return err;
404 	}
405 
406 	if (rhwdep)
407 		*rhwdep = hwdep;
408 	return 0;
409 }
410 EXPORT_SYMBOL(snd_hwdep_new);
411 
412 static int snd_hwdep_dev_free(struct snd_device *device)
413 {
414 	struct snd_hwdep *hwdep = device->device_data;
415 	if (!hwdep)
416 		return 0;
417 	if (hwdep->private_free)
418 		hwdep->private_free(hwdep);
419 	put_device(&hwdep->dev);
420 	return 0;
421 }
422 
423 static int snd_hwdep_dev_register(struct snd_device *device)
424 {
425 	struct snd_hwdep *hwdep = device->device_data;
426 	struct snd_card *card = hwdep->card;
427 	int err;
428 
429 	mutex_lock(&register_mutex);
430 	if (snd_hwdep_search(card, hwdep->device)) {
431 		mutex_unlock(&register_mutex);
432 		return -EBUSY;
433 	}
434 	list_add_tail(&hwdep->list, &snd_hwdep_devices);
435 	err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
436 				  hwdep->card, hwdep->device,
437 				  &snd_hwdep_f_ops, hwdep, &hwdep->dev);
438 	if (err < 0) {
439 		dev_err(&hwdep->dev, "unable to register\n");
440 		list_del(&hwdep->list);
441 		mutex_unlock(&register_mutex);
442 		return err;
443 	}
444 
445 #ifdef CONFIG_SND_OSSEMUL
446 	hwdep->ossreg = 0;
447 	if (hwdep->oss_type >= 0) {
448 		if (hwdep->oss_type == SNDRV_OSS_DEVICE_TYPE_DMFM &&
449 		    hwdep->device)
450 			dev_warn(&hwdep->dev,
451 				 "only hwdep device 0 can be registered as OSS direct FM device!\n");
452 		else if (snd_register_oss_device(hwdep->oss_type,
453 						 card, hwdep->device,
454 						 &snd_hwdep_f_ops, hwdep) < 0)
455 			dev_warn(&hwdep->dev,
456 				 "unable to register OSS compatibility device\n");
457 		else
458 			hwdep->ossreg = 1;
459 	}
460 #endif
461 	mutex_unlock(&register_mutex);
462 	return 0;
463 }
464 
465 static int snd_hwdep_dev_disconnect(struct snd_device *device)
466 {
467 	struct snd_hwdep *hwdep = device->device_data;
468 
469 	if (snd_BUG_ON(!hwdep))
470 		return -ENXIO;
471 	mutex_lock(&register_mutex);
472 	if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {
473 		mutex_unlock(&register_mutex);
474 		return -EINVAL;
475 	}
476 	mutex_lock(&hwdep->open_mutex);
477 	wake_up(&hwdep->open_wait);
478 #ifdef CONFIG_SND_OSSEMUL
479 	if (hwdep->ossreg)
480 		snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
481 #endif
482 	snd_unregister_device(&hwdep->dev);
483 	list_del_init(&hwdep->list);
484 	mutex_unlock(&hwdep->open_mutex);
485 	mutex_unlock(&register_mutex);
486 	return 0;
487 }
488 
489 #ifdef CONFIG_PROC_FS
490 /*
491  *  Info interface
492  */
493 
494 static void snd_hwdep_proc_read(struct snd_info_entry *entry,
495 				struct snd_info_buffer *buffer)
496 {
497 	struct snd_hwdep *hwdep;
498 
499 	mutex_lock(&register_mutex);
500 	list_for_each_entry(hwdep, &snd_hwdep_devices, list)
501 		snd_iprintf(buffer, "%02i-%02i: %s\n",
502 			    hwdep->card->number, hwdep->device, hwdep->name);
503 	mutex_unlock(&register_mutex);
504 }
505 
506 static struct snd_info_entry *snd_hwdep_proc_entry;
507 
508 static void __init snd_hwdep_proc_init(void)
509 {
510 	struct snd_info_entry *entry;
511 
512 	if ((entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL)) != NULL) {
513 		entry->c.text.read = snd_hwdep_proc_read;
514 		if (snd_info_register(entry) < 0) {
515 			snd_info_free_entry(entry);
516 			entry = NULL;
517 		}
518 	}
519 	snd_hwdep_proc_entry = entry;
520 }
521 
522 static void __exit snd_hwdep_proc_done(void)
523 {
524 	snd_info_free_entry(snd_hwdep_proc_entry);
525 }
526 #else /* !CONFIG_PROC_FS */
527 #define snd_hwdep_proc_init()
528 #define snd_hwdep_proc_done()
529 #endif /* CONFIG_PROC_FS */
530 
531 
532 /*
533  *  ENTRY functions
534  */
535 
536 static int __init alsa_hwdep_init(void)
537 {
538 	snd_hwdep_proc_init();
539 	snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
540 	snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
541 	return 0;
542 }
543 
544 static void __exit alsa_hwdep_exit(void)
545 {
546 	snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
547 	snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
548 	snd_hwdep_proc_done();
549 }
550 
551 module_init(alsa_hwdep_init)
552 module_exit(alsa_hwdep_exit)
553