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         scoped_guard(mutex, &hw->open_mutex) {
 153                 if (hw->ops.release)
 154                         err = hw->ops.release(hw, file);
 155                 if (hw->used > 0)
 156                         hw->used--;
 157         }
 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
 276                         scoped_guard(mutex, &register_mutex) {
 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                         }
 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;
 300                         struct snd_hwdep *hwdep;
 301
 302                         if (get_user(device, &info->device))
 303                                 return -EFAULT;
 304                         scoped_guard(mutex, &register_mutex) {
 305                                 hwdep = snd_hwdep_search(card, device);
 306                                 if (!hwdep)
 307                                         return -ENXIO;
 308                                 return snd_hwdep_info(hwdep, info);
 309                         }
 310                         break;
 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
 340 static void snd_hwdep_free(struct snd_hwdep *hwdep)
 341 {
 342         if (!hwdep)
 343                 return;
 344         if (hwdep->private_free)
 345                 hwdep->private_free(hwdep);
 346         put_device(hwdep->dev);
 347         kfree(hwdep);
 348 }
 349
 350 /**
 351  * snd_hwdep_new - create a new hwdep instance
 352  * @card: the card instance
 353  * @id: the id string
 354  * @device: the device index (zero-based)
 355  * @rhwdep: the pointer to store the new hwdep instance
 356  *
 357  * Creates a new hwdep instance with the given index on the card.
 358  * The callbacks (hwdep->ops) must be set on the returned instance
 359  * after this call manually by the caller.
 360  *
 361  * Return: Zero if successful, or a negative error code on failure.
 362  */
 363 int snd_hwdep_new(struct snd_card *card, char *id, int device,
 364                   struct snd_hwdep **rhwdep)
 365 {
 366         struct snd_hwdep *hwdep;
 367         int err;
 368         static const struct snd_device_ops ops = {
 369                 .dev_free = snd_hwdep_dev_free,
 370                 .dev_register = snd_hwdep_dev_register,
 371                 .dev_disconnect = snd_hwdep_dev_disconnect,
 372         };
 373
 374         if (snd_BUG_ON(!card))
 375                 return -ENXIO;
 376         if (rhwdep)
 377                 *rhwdep = NULL;
 378         hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
 379         if (!hwdep)
 380                 return -ENOMEM;
 381
 382         init_waitqueue_head(&hwdep->open_wait);
 383         mutex_init(&hwdep->open_mutex);
 384         hwdep->card = card;
 385         hwdep->device = device;
 386         if (id)
 387                 strscpy(hwdep->id, id, sizeof(hwdep->id));
 388
 389         err = snd_device_alloc(&hwdep->dev, card);
 390         if (err < 0) {
 391                 snd_hwdep_free(hwdep);
 392                 return err;
 393         }
 394
 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                 snd_hwdep_free(hwdep);
 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         snd_hwdep_free(device->device_data);
 415         return 0;
 416 }
 417
 418 static int snd_hwdep_dev_register(struct snd_device *device)
 419 {
 420         struct snd_hwdep *hwdep = device->device_data;
 421         struct snd_card *card = hwdep->card;
 422         int err;
 423
 424         guard(mutex)(&register_mutex);
 425         if (snd_hwdep_search(card, hwdep->device))
 426                 return -EBUSY;
 427         list_add_tail(&hwdep->list, &snd_hwdep_devices);
 428         err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
 429                                   hwdep->card, hwdep->device,
 430                                   &snd_hwdep_f_ops, hwdep, hwdep->dev);
 431         if (err < 0) {
 432                 dev_err(hwdep->dev, "unable to register\n");
 433                 list_del(&hwdep->list);
 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         return 0;
 454 }
 455
 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         guard(mutex)(&register_mutex);
 463         if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep)
 464                 return -EINVAL;
 465         guard(mutex)(&hwdep->open_mutex);
 466         wake_up(&hwdep->open_wait);
 467 #ifdef CONFIG_SND_OSSEMUL
 468         if (hwdep->ossreg)
 469                 snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
 470 #endif
 471         snd_unregister_device(hwdep->dev);
 472         list_del_init(&hwdep->list);
 473         return 0;
 474 }
 475
 476 #ifdef CONFIG_SND_PROC_FS
 477 /*
 478  *  Info interface
 479  */
 480
 481 static void snd_hwdep_proc_read(struct snd_info_entry *entry,
 482                                 struct snd_info_buffer *buffer)
 483 {
 484         struct snd_hwdep *hwdep;
 485
 486         guard(mutex)(&register_mutex);
 487         list_for_each_entry(hwdep, &snd_hwdep_devices, list)
 488                 snd_iprintf(buffer, "%02i-%02i: %s\n",
 489                             hwdep->card->number, hwdep->device, hwdep->name);
 490 }
 491
 492 static struct snd_info_entry *snd_hwdep_proc_entry;
 493
 494 static void __init snd_hwdep_proc_init(void)
 495 {
 496         struct snd_info_entry *entry;
 497
 498         entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL);
 499         if (entry) {
 500                 entry->c.text.read = snd_hwdep_proc_read;
 501                 if (snd_info_register(entry) < 0) {
 502                         snd_info_free_entry(entry);
 503                         entry = NULL;
 504                 }
 505         }
 506         snd_hwdep_proc_entry = entry;
 507 }
 508
 509 static void __exit snd_hwdep_proc_done(void)
 510 {
 511         snd_info_free_entry(snd_hwdep_proc_entry);
 512 }
 513 #else /* !CONFIG_SND_PROC_FS */
 514 #define snd_hwdep_proc_init()
 515 #define snd_hwdep_proc_done()
 516 #endif /* CONFIG_SND_PROC_FS */
 517
 518
 519 /*
 520  *  ENTRY functions
 521  */
 522
 523 static int __init alsa_hwdep_init(void)
 524 {
 525         snd_hwdep_proc_init();
 526         snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
 527         snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
 528         return 0;
 529 }
 530
 531 static void __exit alsa_hwdep_exit(void)
 532 {
 533         snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
 534         snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
 535         snd_hwdep_proc_done();
 536 }
 537
 538 module_init(alsa_hwdep_init)
 539 module_exit(alsa_hwdep_exit)