sound/core/hwdep.c

   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
  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
  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
  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
  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
  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
 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
 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
 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
 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
 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
 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
 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
 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
 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(&register_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(&register_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(&register_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(&register_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
 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  */
 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
 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
 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(&register_mutex);
 422         if (snd_hwdep_search(card, hwdep->device)) {
 423                 mutex_unlock(&register_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(&register_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(&register_mutex);
 454         return 0;
 455 }
 456
 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(&register_mutex);
 464         if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {
 465                 mutex_unlock(&register_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(&register_mutex);
 478         return 0;
 479 }
 480
 481 #ifdef CONFIG_SND_PROC_FS
 482 /*
 483  *  Info interface
 484  */
 485
 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(&register_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(&register_mutex);
 496 }
 497
 498 static struct snd_info_entry *snd_hwdep_proc_entry;
 499
 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
 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
 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
 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)