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 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 mutex_lock(®ister_mutex);
276
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 mutex_unlock(®ister_mutex);
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, err;
300 struct snd_hwdep *hwdep;
301
302 if (get_user(device, &info->device))
303 return -EFAULT;
304 mutex_lock(®ister_mutex);
305 hwdep = snd_hwdep_search(card, device);
306 if (hwdep)
307 err = snd_hwdep_info(hwdep, info);
308 else
309 err = -ENXIO;
310 mutex_unlock(®ister_mutex);
311 return err;
312 }
313 }
314 return -ENOIOCTLCMD;
315 }
316
317 #ifdef CONFIG_COMPAT
318 #include "hwdep_compat.c"
319 #else
320 #define snd_hwdep_ioctl_compat NULL
321 #endif
322
323 /*
324
325 */
326
327 static const struct file_operations snd_hwdep_f_ops =
328 {
329 .owner = THIS_MODULE,
330 .llseek = snd_hwdep_llseek,
331 .read = snd_hwdep_read,
332 .write = snd_hwdep_write,
333 .open = snd_hwdep_open,
334 .release = snd_hwdep_release,
335 .poll = snd_hwdep_poll,
336 .unlocked_ioctl = snd_hwdep_ioctl,
337 .compat_ioctl = snd_hwdep_ioctl_compat,
338 .mmap = snd_hwdep_mmap,
339 };
340
snd_hwdep_free(struct snd_hwdep * hwdep)341 static void snd_hwdep_free(struct snd_hwdep *hwdep)
342 {
343 if (!hwdep)
344 return;
345 if (hwdep->private_free)
346 hwdep->private_free(hwdep);
347 put_device(hwdep->dev);
348 kfree(hwdep);
349 }
350
351 /**
352 * snd_hwdep_new - create a new hwdep instance
353 * @card: the card instance
354 * @id: the id string
355 * @device: the device index (zero-based)
356 * @rhwdep: the pointer to store the new hwdep instance
357 *
358 * Creates a new hwdep instance with the given index on the card.
359 * The callbacks (hwdep->ops) must be set on the returned instance
360 * after this call manually by the caller.
361 *
362 * Return: Zero if successful, or a negative error code on failure.
363 */
snd_hwdep_new(struct snd_card * card,char * id,int device,struct snd_hwdep ** rhwdep)364 int snd_hwdep_new(struct snd_card *card, char *id, int device,
365 struct snd_hwdep **rhwdep)
366 {
367 struct snd_hwdep *hwdep;
368 int err;
369 static const struct snd_device_ops ops = {
370 .dev_free = snd_hwdep_dev_free,
371 .dev_register = snd_hwdep_dev_register,
372 .dev_disconnect = snd_hwdep_dev_disconnect,
373 };
374
375 if (snd_BUG_ON(!card))
376 return -ENXIO;
377 if (rhwdep)
378 *rhwdep = NULL;
379 hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
380 if (!hwdep)
381 return -ENOMEM;
382
383 init_waitqueue_head(&hwdep->open_wait);
384 mutex_init(&hwdep->open_mutex);
385 hwdep->card = card;
386 hwdep->device = device;
387 if (id)
388 strscpy(hwdep->id, id, sizeof(hwdep->id));
389
390 err = snd_device_alloc(&hwdep->dev, card);
391 if (err < 0) {
392 snd_hwdep_free(hwdep);
393 return err;
394 }
395
396 dev_set_name(hwdep->dev, "hwC%iD%i", card->number, device);
397 #ifdef CONFIG_SND_OSSEMUL
398 hwdep->oss_type = -1;
399 #endif
400
401 err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops);
402 if (err < 0) {
403 snd_hwdep_free(hwdep);
404 return err;
405 }
406
407 if (rhwdep)
408 *rhwdep = hwdep;
409 return 0;
410 }
411 EXPORT_SYMBOL(snd_hwdep_new);
412
snd_hwdep_dev_free(struct snd_device * device)413 static int snd_hwdep_dev_free(struct snd_device *device)
414 {
415 snd_hwdep_free(device->device_data);
416 return 0;
417 }
418
snd_hwdep_dev_register(struct snd_device * device)419 static int snd_hwdep_dev_register(struct snd_device *device)
420 {
421 struct snd_hwdep *hwdep = device->device_data;
422 struct snd_card *card = hwdep->card;
423 int err;
424
425 mutex_lock(®ister_mutex);
426 if (snd_hwdep_search(card, hwdep->device)) {
427 mutex_unlock(®ister_mutex);
428 return -EBUSY;
429 }
430 list_add_tail(&hwdep->list, &snd_hwdep_devices);
431 err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
432 hwdep->card, hwdep->device,
433 &snd_hwdep_f_ops, hwdep, hwdep->dev);
434 if (err < 0) {
435 dev_err(hwdep->dev, "unable to register\n");
436 list_del(&hwdep->list);
437 mutex_unlock(®ister_mutex);
438 return err;
439 }
440
441 #ifdef CONFIG_SND_OSSEMUL
442 hwdep->ossreg = 0;
443 if (hwdep->oss_type >= 0) {
444 if (hwdep->oss_type == SNDRV_OSS_DEVICE_TYPE_DMFM &&
445 hwdep->device)
446 dev_warn(hwdep->dev,
447 "only hwdep device 0 can be registered as OSS direct FM device!\n");
448 else if (snd_register_oss_device(hwdep->oss_type,
449 card, hwdep->device,
450 &snd_hwdep_f_ops, hwdep) < 0)
451 dev_warn(hwdep->dev,
452 "unable to register OSS compatibility device\n");
453 else
454 hwdep->ossreg = 1;
455 }
456 #endif
457 mutex_unlock(®ister_mutex);
458 return 0;
459 }
460
snd_hwdep_dev_disconnect(struct snd_device * device)461 static int snd_hwdep_dev_disconnect(struct snd_device *device)
462 {
463 struct snd_hwdep *hwdep = device->device_data;
464
465 if (snd_BUG_ON(!hwdep))
466 return -ENXIO;
467 mutex_lock(®ister_mutex);
468 if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {
469 mutex_unlock(®ister_mutex);
470 return -EINVAL;
471 }
472 mutex_lock(&hwdep->open_mutex);
473 wake_up(&hwdep->open_wait);
474 #ifdef CONFIG_SND_OSSEMUL
475 if (hwdep->ossreg)
476 snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
477 #endif
478 snd_unregister_device(hwdep->dev);
479 list_del_init(&hwdep->list);
480 mutex_unlock(&hwdep->open_mutex);
481 mutex_unlock(®ister_mutex);
482 return 0;
483 }
484
485 #ifdef CONFIG_SND_PROC_FS
486 /*
487 * Info interface
488 */
489
snd_hwdep_proc_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)490 static void snd_hwdep_proc_read(struct snd_info_entry *entry,
491 struct snd_info_buffer *buffer)
492 {
493 struct snd_hwdep *hwdep;
494
495 mutex_lock(®ister_mutex);
496 list_for_each_entry(hwdep, &snd_hwdep_devices, list)
497 snd_iprintf(buffer, "%02i-%02i: %s\n",
498 hwdep->card->number, hwdep->device, hwdep->name);
499 mutex_unlock(®ister_mutex);
500 }
501
502 static struct snd_info_entry *snd_hwdep_proc_entry;
503
snd_hwdep_proc_init(void)504 static void __init snd_hwdep_proc_init(void)
505 {
506 struct snd_info_entry *entry;
507
508 entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL);
509 if (entry) {
510 entry->c.text.read = snd_hwdep_proc_read;
511 if (snd_info_register(entry) < 0) {
512 snd_info_free_entry(entry);
513 entry = NULL;
514 }
515 }
516 snd_hwdep_proc_entry = entry;
517 }
518
snd_hwdep_proc_done(void)519 static void __exit snd_hwdep_proc_done(void)
520 {
521 snd_info_free_entry(snd_hwdep_proc_entry);
522 }
523 #else /* !CONFIG_SND_PROC_FS */
524 #define snd_hwdep_proc_init()
525 #define snd_hwdep_proc_done()
526 #endif /* CONFIG_SND_PROC_FS */
527
528
529 /*
530 * ENTRY functions
531 */
532
alsa_hwdep_init(void)533 static int __init alsa_hwdep_init(void)
534 {
535 snd_hwdep_proc_init();
536 snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
537 snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
538 return 0;
539 }
540
alsa_hwdep_exit(void)541 static void __exit alsa_hwdep_exit(void)
542 {
543 snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
544 snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
545 snd_hwdep_proc_done();
546 }
547
548 module_init(alsa_hwdep_init)
549 module_exit(alsa_hwdep_exit)
550