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
release_hwdep_device(struct device * dev)341 static void release_hwdep_device(struct device *dev)
342 {
343 kfree(container_of(dev, struct snd_hwdep, dev));
344 }
345
346 /**
347 * snd_hwdep_new - create a new hwdep instance
348 * @card: the card instance
349 * @id: the id string
350 * @device: the device index (zero-based)
351 * @rhwdep: the pointer to store the new hwdep instance
352 *
353 * Creates a new hwdep instance with the given index on the card.
354 * The callbacks (hwdep->ops) must be set on the returned instance
355 * after this call manually by the caller.
356 *
357 * Return: Zero if successful, or a negative error code on failure.
358 */
snd_hwdep_new(struct snd_card * card,char * id,int device,struct snd_hwdep ** rhwdep)359 int snd_hwdep_new(struct snd_card *card, char *id, int device,
360 struct snd_hwdep **rhwdep)
361 {
362 struct snd_hwdep *hwdep;
363 int err;
364 static const struct snd_device_ops ops = {
365 .dev_free = snd_hwdep_dev_free,
366 .dev_register = snd_hwdep_dev_register,
367 .dev_disconnect = snd_hwdep_dev_disconnect,
368 };
369
370 if (snd_BUG_ON(!card))
371 return -ENXIO;
372 if (rhwdep)
373 *rhwdep = NULL;
374 hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
375 if (!hwdep)
376 return -ENOMEM;
377
378 init_waitqueue_head(&hwdep->open_wait);
379 mutex_init(&hwdep->open_mutex);
380 hwdep->card = card;
381 hwdep->device = device;
382 if (id)
383 strscpy(hwdep->id, id, sizeof(hwdep->id));
384
385 snd_device_initialize(&hwdep->dev, card);
386 hwdep->dev.release = release_hwdep_device;
387 dev_set_name(&hwdep->dev, "hwC%iD%i", card->number, device);
388 #ifdef CONFIG_SND_OSSEMUL
389 hwdep->oss_type = -1;
390 #endif
391
392 err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops);
393 if (err < 0) {
394 put_device(&hwdep->dev);
395 return err;
396 }
397
398 if (rhwdep)
399 *rhwdep = hwdep;
400 return 0;
401 }
402 EXPORT_SYMBOL(snd_hwdep_new);
403
snd_hwdep_dev_free(struct snd_device * device)404 static int snd_hwdep_dev_free(struct snd_device *device)
405 {
406 struct snd_hwdep *hwdep = device->device_data;
407 if (!hwdep)
408 return 0;
409 if (hwdep->private_free)
410 hwdep->private_free(hwdep);
411 put_device(&hwdep->dev);
412 return 0;
413 }
414
snd_hwdep_dev_register(struct snd_device * device)415 static int snd_hwdep_dev_register(struct snd_device *device)
416 {
417 struct snd_hwdep *hwdep = device->device_data;
418 struct snd_card *card = hwdep->card;
419 int err;
420
421 mutex_lock(®ister_mutex);
422 if (snd_hwdep_search(card, hwdep->device)) {
423 mutex_unlock(®ister_mutex);
424 return -EBUSY;
425 }
426 list_add_tail(&hwdep->list, &snd_hwdep_devices);
427 err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
428 hwdep->card, hwdep->device,
429 &snd_hwdep_f_ops, hwdep, &hwdep->dev);
430 if (err < 0) {
431 dev_err(&hwdep->dev, "unable to register\n");
432 list_del(&hwdep->list);
433 mutex_unlock(®ister_mutex);
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 mutex_unlock(®ister_mutex);
454 return 0;
455 }
456
snd_hwdep_dev_disconnect(struct snd_device * device)457 static int snd_hwdep_dev_disconnect(struct snd_device *device)
458 {
459 struct snd_hwdep *hwdep = device->device_data;
460
461 if (snd_BUG_ON(!hwdep))
462 return -ENXIO;
463 mutex_lock(®ister_mutex);
464 if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {
465 mutex_unlock(®ister_mutex);
466 return -EINVAL;
467 }
468 mutex_lock(&hwdep->open_mutex);
469 wake_up(&hwdep->open_wait);
470 #ifdef CONFIG_SND_OSSEMUL
471 if (hwdep->ossreg)
472 snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
473 #endif
474 snd_unregister_device(&hwdep->dev);
475 list_del_init(&hwdep->list);
476 mutex_unlock(&hwdep->open_mutex);
477 mutex_unlock(®ister_mutex);
478 return 0;
479 }
480
481 #ifdef CONFIG_SND_PROC_FS
482 /*
483 * Info interface
484 */
485
snd_hwdep_proc_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)486 static void snd_hwdep_proc_read(struct snd_info_entry *entry,
487 struct snd_info_buffer *buffer)
488 {
489 struct snd_hwdep *hwdep;
490
491 mutex_lock(®ister_mutex);
492 list_for_each_entry(hwdep, &snd_hwdep_devices, list)
493 snd_iprintf(buffer, "%02i-%02i: %s\n",
494 hwdep->card->number, hwdep->device, hwdep->name);
495 mutex_unlock(®ister_mutex);
496 }
497
498 static struct snd_info_entry *snd_hwdep_proc_entry;
499
snd_hwdep_proc_init(void)500 static void __init snd_hwdep_proc_init(void)
501 {
502 struct snd_info_entry *entry;
503
504 entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL);
505 if (entry) {
506 entry->c.text.read = snd_hwdep_proc_read;
507 if (snd_info_register(entry) < 0) {
508 snd_info_free_entry(entry);
509 entry = NULL;
510 }
511 }
512 snd_hwdep_proc_entry = entry;
513 }
514
snd_hwdep_proc_done(void)515 static void __exit snd_hwdep_proc_done(void)
516 {
517 snd_info_free_entry(snd_hwdep_proc_entry);
518 }
519 #else /* !CONFIG_SND_PROC_FS */
520 #define snd_hwdep_proc_init()
521 #define snd_hwdep_proc_done()
522 #endif /* CONFIG_SND_PROC_FS */
523
524
525 /*
526 * ENTRY functions
527 */
528
alsa_hwdep_init(void)529 static int __init alsa_hwdep_init(void)
530 {
531 snd_hwdep_proc_init();
532 snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
533 snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
534 return 0;
535 }
536
alsa_hwdep_exit(void)537 static void __exit alsa_hwdep_exit(void)
538 {
539 snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
540 snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
541 snd_hwdep_proc_done();
542 }
543
544 module_init(alsa_hwdep_init)
545 module_exit(alsa_hwdep_exit)
546