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 mutex_lock(&hw->open_mutex);
153 if (hw->ops.release)
154 err = hw->ops.release(hw, file);
155 if (hw->used > 0)
156 hw->used--;
157 mutex_unlock(&hw->open_mutex);
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 strlcpy(info.id, hw->id, sizeof(info.id));
181 strlcpy(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 if ((err = hw->ops.dsp_status(hw, &info)) < 0)
199 return err;
200 if (copy_to_user(_info, &info, sizeof(info)))
201 return -EFAULT;
202 return 0;
203 }
204
snd_hwdep_dsp_load(struct snd_hwdep * hw,struct snd_hwdep_dsp_image * info)205 static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
206 struct snd_hwdep_dsp_image *info)
207 {
208 int err;
209
210 if (! hw->ops.dsp_load)
211 return -ENXIO;
212 if (info->index >= 32)
213 return -EINVAL;
214 /* check whether the dsp was already loaded */
215 if (hw->dsp_loaded & (1u << info->index))
216 return -EBUSY;
217 err = hw->ops.dsp_load(hw, info);
218 if (err < 0)
219 return err;
220 hw->dsp_loaded |= (1u << info->index);
221 return 0;
222 }
223
snd_hwdep_dsp_load_user(struct snd_hwdep * hw,struct snd_hwdep_dsp_image __user * _info)224 static int snd_hwdep_dsp_load_user(struct snd_hwdep *hw,
225 struct snd_hwdep_dsp_image __user *_info)
226 {
227 struct snd_hwdep_dsp_image info = {};
228
229 if (copy_from_user(&info, _info, sizeof(info)))
230 return -EFAULT;
231 return snd_hwdep_dsp_load(hw, &info);
232 }
233
234
snd_hwdep_ioctl(struct file * file,unsigned int cmd,unsigned long arg)235 static long snd_hwdep_ioctl(struct file * file, unsigned int cmd,
236 unsigned long arg)
237 {
238 struct snd_hwdep *hw = file->private_data;
239 void __user *argp = (void __user *)arg;
240 switch (cmd) {
241 case SNDRV_HWDEP_IOCTL_PVERSION:
242 return put_user(SNDRV_HWDEP_VERSION, (int __user *)argp);
243 case SNDRV_HWDEP_IOCTL_INFO:
244 return snd_hwdep_info(hw, argp);
245 case SNDRV_HWDEP_IOCTL_DSP_STATUS:
246 return snd_hwdep_dsp_status(hw, argp);
247 case SNDRV_HWDEP_IOCTL_DSP_LOAD:
248 return snd_hwdep_dsp_load_user(hw, argp);
249 }
250 if (hw->ops.ioctl)
251 return hw->ops.ioctl(hw, file, cmd, arg);
252 return -ENOTTY;
253 }
254
snd_hwdep_mmap(struct file * file,struct vm_area_struct * vma)255 static int snd_hwdep_mmap(struct file * file, struct vm_area_struct * vma)
256 {
257 struct snd_hwdep *hw = file->private_data;
258 if (hw->ops.mmap)
259 return hw->ops.mmap(hw, file, vma);
260 return -ENXIO;
261 }
262
snd_hwdep_control_ioctl(struct snd_card * card,struct snd_ctl_file * control,unsigned int cmd,unsigned long arg)263 static int snd_hwdep_control_ioctl(struct snd_card *card,
264 struct snd_ctl_file * control,
265 unsigned int cmd, unsigned long arg)
266 {
267 switch (cmd) {
268 case SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE:
269 {
270 int device;
271
272 if (get_user(device, (int __user *)arg))
273 return -EFAULT;
274 mutex_lock(®ister_mutex);
275
276 if (device < 0)
277 device = 0;
278 else if (device < SNDRV_MINOR_HWDEPS)
279 device++;
280 else
281 device = SNDRV_MINOR_HWDEPS;
282
283 while (device < SNDRV_MINOR_HWDEPS) {
284 if (snd_hwdep_search(card, device))
285 break;
286 device++;
287 }
288 if (device >= SNDRV_MINOR_HWDEPS)
289 device = -1;
290 mutex_unlock(®ister_mutex);
291 if (put_user(device, (int __user *)arg))
292 return -EFAULT;
293 return 0;
294 }
295 case SNDRV_CTL_IOCTL_HWDEP_INFO:
296 {
297 struct snd_hwdep_info __user *info = (struct snd_hwdep_info __user *)arg;
298 int device, err;
299 struct snd_hwdep *hwdep;
300
301 if (get_user(device, &info->device))
302 return -EFAULT;
303 mutex_lock(®ister_mutex);
304 hwdep = snd_hwdep_search(card, device);
305 if (hwdep)
306 err = snd_hwdep_info(hwdep, info);
307 else
308 err = -ENXIO;
309 mutex_unlock(®ister_mutex);
310 return err;
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
release_hwdep_device(struct device * dev)340 static void release_hwdep_device(struct device *dev)
341 {
342 kfree(container_of(dev, struct snd_hwdep, dev));
343 }
344
345 /**
346 * snd_hwdep_new - create a new hwdep instance
347 * @card: the card instance
348 * @id: the id string
349 * @device: the device index (zero-based)
350 * @rhwdep: the pointer to store the new hwdep instance
351 *
352 * Creates a new hwdep instance with the given index on the card.
353 * The callbacks (hwdep->ops) must be set on the returned instance
354 * after this call manually by the caller.
355 *
356 * Return: Zero if successful, or a negative error code on failure.
357 */
snd_hwdep_new(struct snd_card * card,char * id,int device,struct snd_hwdep ** rhwdep)358 int snd_hwdep_new(struct snd_card *card, char *id, int device,
359 struct snd_hwdep **rhwdep)
360 {
361 struct snd_hwdep *hwdep;
362 int err;
363 static const struct snd_device_ops ops = {
364 .dev_free = snd_hwdep_dev_free,
365 .dev_register = snd_hwdep_dev_register,
366 .dev_disconnect = snd_hwdep_dev_disconnect,
367 };
368
369 if (snd_BUG_ON(!card))
370 return -ENXIO;
371 if (rhwdep)
372 *rhwdep = NULL;
373 hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
374 if (!hwdep)
375 return -ENOMEM;
376
377 init_waitqueue_head(&hwdep->open_wait);
378 mutex_init(&hwdep->open_mutex);
379 hwdep->card = card;
380 hwdep->device = device;
381 if (id)
382 strlcpy(hwdep->id, id, sizeof(hwdep->id));
383
384 snd_device_initialize(&hwdep->dev, card);
385 hwdep->dev.release = release_hwdep_device;
386 dev_set_name(&hwdep->dev, "hwC%iD%i", card->number, device);
387 #ifdef CONFIG_SND_OSSEMUL
388 hwdep->oss_type = -1;
389 #endif
390
391 err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops);
392 if (err < 0) {
393 put_device(&hwdep->dev);
394 return err;
395 }
396
397 if (rhwdep)
398 *rhwdep = hwdep;
399 return 0;
400 }
401 EXPORT_SYMBOL(snd_hwdep_new);
402
snd_hwdep_dev_free(struct snd_device * device)403 static int snd_hwdep_dev_free(struct snd_device *device)
404 {
405 struct snd_hwdep *hwdep = device->device_data;
406 if (!hwdep)
407 return 0;
408 if (hwdep->private_free)
409 hwdep->private_free(hwdep);
410 put_device(&hwdep->dev);
411 return 0;
412 }
413
snd_hwdep_dev_register(struct snd_device * device)414 static int snd_hwdep_dev_register(struct snd_device *device)
415 {
416 struct snd_hwdep *hwdep = device->device_data;
417 struct snd_card *card = hwdep->card;
418 int err;
419
420 mutex_lock(®ister_mutex);
421 if (snd_hwdep_search(card, hwdep->device)) {
422 mutex_unlock(®ister_mutex);
423 return -EBUSY;
424 }
425 list_add_tail(&hwdep->list, &snd_hwdep_devices);
426 err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
427 hwdep->card, hwdep->device,
428 &snd_hwdep_f_ops, hwdep, &hwdep->dev);
429 if (err < 0) {
430 dev_err(&hwdep->dev, "unable to register\n");
431 list_del(&hwdep->list);
432 mutex_unlock(®ister_mutex);
433 return err;
434 }
435
436 #ifdef CONFIG_SND_OSSEMUL
437 hwdep->ossreg = 0;
438 if (hwdep->oss_type >= 0) {
439 if (hwdep->oss_type == SNDRV_OSS_DEVICE_TYPE_DMFM &&
440 hwdep->device)
441 dev_warn(&hwdep->dev,
442 "only hwdep device 0 can be registered as OSS direct FM device!\n");
443 else if (snd_register_oss_device(hwdep->oss_type,
444 card, hwdep->device,
445 &snd_hwdep_f_ops, hwdep) < 0)
446 dev_warn(&hwdep->dev,
447 "unable to register OSS compatibility device\n");
448 else
449 hwdep->ossreg = 1;
450 }
451 #endif
452 mutex_unlock(®ister_mutex);
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 mutex_lock(®ister_mutex);
463 if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {
464 mutex_unlock(®ister_mutex);
465 return -EINVAL;
466 }
467 mutex_lock(&hwdep->open_mutex);
468 wake_up(&hwdep->open_wait);
469 #ifdef CONFIG_SND_OSSEMUL
470 if (hwdep->ossreg)
471 snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
472 #endif
473 snd_unregister_device(&hwdep->dev);
474 list_del_init(&hwdep->list);
475 mutex_unlock(&hwdep->open_mutex);
476 mutex_unlock(®ister_mutex);
477 return 0;
478 }
479
480 #ifdef CONFIG_SND_PROC_FS
481 /*
482 * Info interface
483 */
484
snd_hwdep_proc_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)485 static void snd_hwdep_proc_read(struct snd_info_entry *entry,
486 struct snd_info_buffer *buffer)
487 {
488 struct snd_hwdep *hwdep;
489
490 mutex_lock(®ister_mutex);
491 list_for_each_entry(hwdep, &snd_hwdep_devices, list)
492 snd_iprintf(buffer, "%02i-%02i: %s\n",
493 hwdep->card->number, hwdep->device, hwdep->name);
494 mutex_unlock(®ister_mutex);
495 }
496
497 static struct snd_info_entry *snd_hwdep_proc_entry;
498
snd_hwdep_proc_init(void)499 static void __init snd_hwdep_proc_init(void)
500 {
501 struct snd_info_entry *entry;
502
503 if ((entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL)) != NULL) {
504 entry->c.text.read = snd_hwdep_proc_read;
505 if (snd_info_register(entry) < 0) {
506 snd_info_free_entry(entry);
507 entry = NULL;
508 }
509 }
510 snd_hwdep_proc_entry = entry;
511 }
512
snd_hwdep_proc_done(void)513 static void __exit snd_hwdep_proc_done(void)
514 {
515 snd_info_free_entry(snd_hwdep_proc_entry);
516 }
517 #else /* !CONFIG_SND_PROC_FS */
518 #define snd_hwdep_proc_init()
519 #define snd_hwdep_proc_done()
520 #endif /* CONFIG_SND_PROC_FS */
521
522
523 /*
524 * ENTRY functions
525 */
526
alsa_hwdep_init(void)527 static int __init alsa_hwdep_init(void)
528 {
529 snd_hwdep_proc_init();
530 snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
531 snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
532 return 0;
533 }
534
alsa_hwdep_exit(void)535 static void __exit alsa_hwdep_exit(void)
536 {
537 snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
538 snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
539 snd_hwdep_proc_done();
540 }
541
542 module_init(alsa_hwdep_init)
543 module_exit(alsa_hwdep_exit)
544