sound/core/hwdep.c

   1 /*
   2  *  Hardware dependent layer
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <linux/major.h>
  23 #include <linux/init.h>
  24 #include <linux/slab.h>
  25 #include <linux/time.h>
  26 #include <linux/mutex.h>
  27 #include <linux/module.h>
  28 #include <linux/sched/signal.h>
  29 #include <sound/core.h>
  30 #include <sound/control.h>
  31 #include <sound/minors.h>
  32 #include <sound/hwdep.h>
  33 #include <sound/info.h>
  34
  35 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
  36 MODULE_DESCRIPTION("Hardware dependent layer");
  37 MODULE_LICENSE("GPL");
  38
  39 static LIST_HEAD(snd_hwdep_devices);
  40 static DEFINE_MUTEX(register_mutex);
  41
  42 static int snd_hwdep_dev_free(struct snd_device *device);
  43 static int snd_hwdep_dev_register(struct snd_device *device);
  44 static int snd_hwdep_dev_disconnect(struct snd_device *device);
  45
  46
  47 static struct snd_hwdep *snd_hwdep_search(struct snd_card *card, int device)
  48 {
  49         struct snd_hwdep *hwdep;
  50
  51         list_for_each_entry(hwdep, &snd_hwdep_devices, list)
  52                 if (hwdep->card == card && hwdep->device == device)
  53                         return hwdep;
  54         return NULL;
  55 }
  56
  57 static loff_t snd_hwdep_llseek(struct file * file, loff_t offset, int orig)
  58 {
  59         struct snd_hwdep *hw = file->private_data;
  60         if (hw->ops.llseek)
  61                 return hw->ops.llseek(hw, file, offset, orig);
  62         return -ENXIO;
  63 }
  64
  65 static ssize_t snd_hwdep_read(struct file * file, char __user *buf,
  66                               size_t count, loff_t *offset)
  67 {
  68         struct snd_hwdep *hw = file->private_data;
  69         if (hw->ops.read)
  70                 return hw->ops.read(hw, buf, count, offset);
  71         return -ENXIO;
  72 }
  73
  74 static ssize_t snd_hwdep_write(struct file * file, const char __user *buf,
  75                                size_t count, loff_t *offset)
  76 {
  77         struct snd_hwdep *hw = file->private_data;
  78         if (hw->ops.write)
  79                 return hw->ops.write(hw, buf, count, offset);
  80         return -ENXIO;
  81 }
  82
  83 static int snd_hwdep_open(struct inode *inode, struct file * file)
  84 {
  85         int major = imajor(inode);
  86         struct snd_hwdep *hw;
  87         int err;
  88         wait_queue_entry_t wait;
  89
  90         if (major == snd_major) {
  91                 hw = snd_lookup_minor_data(iminor(inode),
  92                                            SNDRV_DEVICE_TYPE_HWDEP);
  93 #ifdef CONFIG_SND_OSSEMUL
  94         } else if (major == SOUND_MAJOR) {
  95                 hw = snd_lookup_oss_minor_data(iminor(inode),
  96                                                SNDRV_OSS_DEVICE_TYPE_DMFM);
  97 #endif
  98         } else
  99                 return -ENXIO;
 100         if (hw == NULL)
 101                 return -ENODEV;
 102
 103         if (!try_module_get(hw->card->module)) {
 104                 snd_card_unref(hw->card);
 105                 return -EFAULT;
 106         }
 107
 108         init_waitqueue_entry(&wait, current);
 109         add_wait_queue(&hw->open_wait, &wait);
 110         mutex_lock(&hw->open_mutex);
 111         while (1) {
 112                 if (hw->exclusive && hw->used > 0) {
 113                         err = -EBUSY;
 114                         break;
 115                 }
 116                 if (!hw->ops.open) {
 117                         err = 0;
 118                         break;
 119                 }
 120                 err = hw->ops.open(hw, file);
 121                 if (err >= 0)
 122                         break;
 123                 if (err == -EAGAIN) {
 124                         if (file->f_flags & O_NONBLOCK) {
 125                                 err = -EBUSY;
 126                                 break;
 127                         }
 128                 } else
 129                         break;
 130                 set_current_state(TASK_INTERRUPTIBLE);
 131                 mutex_unlock(&hw->open_mutex);
 132                 schedule();
 133                 mutex_lock(&hw->open_mutex);
 134                 if (hw->card->shutdown) {
 135                         err = -ENODEV;
 136                         break;
 137                 }
 138                 if (signal_pending(current)) {
 139                         err = -ERESTARTSYS;
 140                         break;
 141                 }
 142         }
 143         remove_wait_queue(&hw->open_wait, &wait);
 144         if (err >= 0) {
 145                 err = snd_card_file_add(hw->card, file);
 146                 if (err >= 0) {
 147                         file->private_data = hw;
 148                         hw->used++;
 149                 } else {
 150                         if (hw->ops.release)
 151                                 hw->ops.release(hw, file);
 152                 }
 153         }
 154         mutex_unlock(&hw->open_mutex);
 155         if (err < 0)
 156                 module_put(hw->card->module);
 157         snd_card_unref(hw->card);
 158         return err;
 159 }
 160
 161 static int snd_hwdep_release(struct inode *inode, struct file * file)
 162 {
 163         int err = 0;
 164         struct snd_hwdep *hw = file->private_data;
 165         struct module *mod = hw->card->module;
 166
 167         mutex_lock(&hw->open_mutex);
 168         if (hw->ops.release)
 169                 err = hw->ops.release(hw, file);
 170         if (hw->used > 0)
 171                 hw->used--;
 172         mutex_unlock(&hw->open_mutex);
 173         wake_up(&hw->open_wait);
 174
 175         snd_card_file_remove(hw->card, file);
 176         module_put(mod);
 177         return err;
 178 }
 179
 180 static __poll_t snd_hwdep_poll(struct file * file, poll_table * wait)
 181 {
 182         struct snd_hwdep *hw = file->private_data;
 183         if (hw->ops.poll)
 184                 return hw->ops.poll(hw, file, wait);
 185         return 0;
 186 }
 187
 188 static int snd_hwdep_info(struct snd_hwdep *hw,
 189                           struct snd_hwdep_info __user *_info)
 190 {
 191         struct snd_hwdep_info info;
 192
 193         memset(&info, 0, sizeof(info));
 194         info.card = hw->card->number;
 195         strlcpy(info.id, hw->id, sizeof(info.id));
 196         strlcpy(info.name, hw->name, sizeof(info.name));
 197         info.iface = hw->iface;
 198         if (copy_to_user(_info, &info, sizeof(info)))
 199                 return -EFAULT;
 200         return 0;
 201 }
 202
 203 static int snd_hwdep_dsp_status(struct snd_hwdep *hw,
 204                                 struct snd_hwdep_dsp_status __user *_info)
 205 {
 206         struct snd_hwdep_dsp_status info;
 207         int err;
 208
 209         if (! hw->ops.dsp_status)
 210                 return -ENXIO;
 211         memset(&info, 0, sizeof(info));
 212         info.dsp_loaded = hw->dsp_loaded;
 213         if ((err = hw->ops.dsp_status(hw, &info)) < 0)
 214                 return err;
 215         if (copy_to_user(_info, &info, sizeof(info)))
 216                 return -EFAULT;
 217         return 0;
 218 }
 219
 220 static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
 221                               struct snd_hwdep_dsp_image __user *_info)
 222 {
 223         struct snd_hwdep_dsp_image info;
 224         int err;
 225
 226         if (! hw->ops.dsp_load)
 227                 return -ENXIO;
 228         memset(&info, 0, sizeof(info));
 229         if (copy_from_user(&info, _info, sizeof(info)))
 230                 return -EFAULT;
 231         if (info.index >= 32)
 232                 return -EINVAL;
 233         /* check whether the dsp was already loaded */
 234         if (hw->dsp_loaded & (1u << info.index))
 235                 return -EBUSY;
 236         err = hw->ops.dsp_load(hw, &info);
 237         if (err < 0)
 238                 return err;
 239         hw->dsp_loaded |= (1u << info.index);
 240         return 0;
 241 }
 242
 243 static long snd_hwdep_ioctl(struct file * file, unsigned int cmd,
 244                             unsigned long arg)
 245 {
 246         struct snd_hwdep *hw = file->private_data;
 247         void __user *argp = (void __user *)arg;
 248         switch (cmd) {
 249         case SNDRV_HWDEP_IOCTL_PVERSION:
 250                 return put_user(SNDRV_HWDEP_VERSION, (int __user *)argp);
 251         case SNDRV_HWDEP_IOCTL_INFO:
 252                 return snd_hwdep_info(hw, argp);
 253         case SNDRV_HWDEP_IOCTL_DSP_STATUS:
 254                 return snd_hwdep_dsp_status(hw, argp);
 255         case SNDRV_HWDEP_IOCTL_DSP_LOAD:
 256                 return snd_hwdep_dsp_load(hw, argp);
 257         }
 258         if (hw->ops.ioctl)
 259                 return hw->ops.ioctl(hw, file, cmd, arg);
 260         return -ENOTTY;
 261 }
 262
 263 static int snd_hwdep_mmap(struct file * file, struct vm_area_struct * vma)
 264 {
 265         struct snd_hwdep *hw = file->private_data;
 266         if (hw->ops.mmap)
 267                 return hw->ops.mmap(hw, file, vma);
 268         return -ENXIO;
 269 }
 270
 271 static int snd_hwdep_control_ioctl(struct snd_card *card,
 272                                    struct snd_ctl_file * control,
 273                                    unsigned int cmd, unsigned long arg)
 274 {
 275         switch (cmd) {
 276         case SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE:
 277                 {
 278                         int device;
 279
 280                         if (get_user(device, (int __user *)arg))
 281                                 return -EFAULT;
 282                         mutex_lock(&register_mutex);
 283
 284                         if (device < 0)
 285                                 device = 0;
 286                         else if (device < SNDRV_MINOR_HWDEPS)
 287                                 device++;
 288                         else
 289                                 device = SNDRV_MINOR_HWDEPS;
 290
 291                         while (device < SNDRV_MINOR_HWDEPS) {
 292                                 if (snd_hwdep_search(card, device))
 293                                         break;
 294                                 device++;
 295                         }
 296                         if (device >= SNDRV_MINOR_HWDEPS)
 297                                 device = -1;
 298                         mutex_unlock(&register_mutex);
 299                         if (put_user(device, (int __user *)arg))
 300                                 return -EFAULT;
 301                         return 0;
 302                 }
 303         case SNDRV_CTL_IOCTL_HWDEP_INFO:
 304                 {
 305                         struct snd_hwdep_info __user *info = (struct snd_hwdep_info __user *)arg;
 306                         int device, err;
 307                         struct snd_hwdep *hwdep;
 308
 309                         if (get_user(device, &info->device))
 310                                 return -EFAULT;
 311                         mutex_lock(&register_mutex);
 312                         hwdep = snd_hwdep_search(card, device);
 313                         if (hwdep)
 314                                 err = snd_hwdep_info(hwdep, info);
 315                         else
 316                                 err = -ENXIO;
 317                         mutex_unlock(&register_mutex);
 318                         return err;
 319                 }
 320         }
 321         return -ENOIOCTLCMD;
 322 }
 323
 324 #ifdef CONFIG_COMPAT
 325 #include "hwdep_compat.c"
 326 #else
 327 #define snd_hwdep_ioctl_compat  NULL
 328 #endif
 329
 330 /*
 331
 332  */
 333
 334 static const struct file_operations snd_hwdep_f_ops =
 335 {
 336         .owner =        THIS_MODULE,
 337         .llseek =       snd_hwdep_llseek,
 338         .read =         snd_hwdep_read,
 339         .write =        snd_hwdep_write,
 340         .open =         snd_hwdep_open,
 341         .release =      snd_hwdep_release,
 342         .poll =         snd_hwdep_poll,
 343         .unlocked_ioctl =       snd_hwdep_ioctl,
 344         .compat_ioctl = snd_hwdep_ioctl_compat,
 345         .mmap =         snd_hwdep_mmap,
 346 };
 347
 348 static void release_hwdep_device(struct device *dev)
 349 {
 350         kfree(container_of(dev, struct snd_hwdep, dev));
 351 }
 352
 353 /**
 354  * snd_hwdep_new - create a new hwdep instance
 355  * @card: the card instance
 356  * @id: the id string
 357  * @device: the device index (zero-based)
 358  * @rhwdep: the pointer to store the new hwdep instance
 359  *
 360  * Creates a new hwdep instance with the given index on the card.
 361  * The callbacks (hwdep->ops) must be set on the returned instance
 362  * after this call manually by the caller.
 363  *
 364  * Return: Zero if successful, or a negative error code on failure.
 365  */
 366 int snd_hwdep_new(struct snd_card *card, char *id, int device,
 367                   struct snd_hwdep **rhwdep)
 368 {
 369         struct snd_hwdep *hwdep;
 370         int err;
 371         static struct snd_device_ops ops = {
 372                 .dev_free = snd_hwdep_dev_free,
 373                 .dev_register = snd_hwdep_dev_register,
 374                 .dev_disconnect = snd_hwdep_dev_disconnect,
 375         };
 376
 377         if (snd_BUG_ON(!card))
 378                 return -ENXIO;
 379         if (rhwdep)
 380                 *rhwdep = NULL;
 381         hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL);
 382         if (!hwdep)
 383                 return -ENOMEM;
 384
 385         init_waitqueue_head(&hwdep->open_wait);
 386         mutex_init(&hwdep->open_mutex);
 387         hwdep->card = card;
 388         hwdep->device = device;
 389         if (id)
 390                 strlcpy(hwdep->id, id, sizeof(hwdep->id));
 391
 392         snd_device_initialize(&hwdep->dev, card);
 393         hwdep->dev.release = release_hwdep_device;
 394         dev_set_name(&hwdep->dev, "hwC%iD%i", card->number, device);
 395 #ifdef CONFIG_SND_OSSEMUL
 396         hwdep->oss_type = -1;
 397 #endif
 398
 399         err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops);
 400         if (err < 0) {
 401                 put_device(&hwdep->dev);
 402                 return err;
 403         }
 404
 405         if (rhwdep)
 406                 *rhwdep = hwdep;
 407         return 0;
 408 }
 409 EXPORT_SYMBOL(snd_hwdep_new);
 410
 411 static int snd_hwdep_dev_free(struct snd_device *device)
 412 {
 413         struct snd_hwdep *hwdep = device->device_data;
 414         if (!hwdep)
 415                 return 0;
 416         if (hwdep->private_free)
 417                 hwdep->private_free(hwdep);
 418         put_device(&hwdep->dev);
 419         return 0;
 420 }
 421
 422 static int snd_hwdep_dev_register(struct snd_device *device)
 423 {
 424         struct snd_hwdep *hwdep = device->device_data;
 425         struct snd_card *card = hwdep->card;
 426         int err;
 427
 428         mutex_lock(&register_mutex);
 429         if (snd_hwdep_search(card, hwdep->device)) {
 430                 mutex_unlock(&register_mutex);
 431                 return -EBUSY;
 432         }
 433         list_add_tail(&hwdep->list, &snd_hwdep_devices);
 434         err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
 435                                   hwdep->card, hwdep->device,
 436                                   &snd_hwdep_f_ops, hwdep, &hwdep->dev);
 437         if (err < 0) {
 438                 dev_err(&hwdep->dev, "unable to register\n");
 439                 list_del(&hwdep->list);
 440                 mutex_unlock(&register_mutex);
 441                 return err;
 442         }
 443
 444 #ifdef CONFIG_SND_OSSEMUL
 445         hwdep->ossreg = 0;
 446         if (hwdep->oss_type >= 0) {
 447                 if (hwdep->oss_type == SNDRV_OSS_DEVICE_TYPE_DMFM &&
 448                     hwdep->device)
 449                         dev_warn(&hwdep->dev,
 450                                  "only hwdep device 0 can be registered as OSS direct FM device!\n");
 451                 else if (snd_register_oss_device(hwdep->oss_type,
 452                                                  card, hwdep->device,
 453                                                  &snd_hwdep_f_ops, hwdep) < 0)
 454                         dev_warn(&hwdep->dev,
 455                                  "unable to register OSS compatibility device\n");
 456                 else
 457                         hwdep->ossreg = 1;
 458         }
 459 #endif
 460         mutex_unlock(&register_mutex);
 461         return 0;
 462 }
 463
 464 static int snd_hwdep_dev_disconnect(struct snd_device *device)
 465 {
 466         struct snd_hwdep *hwdep = device->device_data;
 467
 468         if (snd_BUG_ON(!hwdep))
 469                 return -ENXIO;
 470         mutex_lock(&register_mutex);
 471         if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) {
 472                 mutex_unlock(&register_mutex);
 473                 return -EINVAL;
 474         }
 475         mutex_lock(&hwdep->open_mutex);
 476         wake_up(&hwdep->open_wait);
 477 #ifdef CONFIG_SND_OSSEMUL
 478         if (hwdep->ossreg)
 479                 snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device);
 480 #endif
 481         snd_unregister_device(&hwdep->dev);
 482         list_del_init(&hwdep->list);
 483         mutex_unlock(&hwdep->open_mutex);
 484         mutex_unlock(&register_mutex);
 485         return 0;
 486 }
 487
 488 #ifdef CONFIG_SND_PROC_FS
 489 /*
 490  *  Info interface
 491  */
 492
 493 static void snd_hwdep_proc_read(struct snd_info_entry *entry,
 494                                 struct snd_info_buffer *buffer)
 495 {
 496         struct snd_hwdep *hwdep;
 497
 498         mutex_lock(&register_mutex);
 499         list_for_each_entry(hwdep, &snd_hwdep_devices, list)
 500                 snd_iprintf(buffer, "%02i-%02i: %s\n",
 501                             hwdep->card->number, hwdep->device, hwdep->name);
 502         mutex_unlock(&register_mutex);
 503 }
 504
 505 static struct snd_info_entry *snd_hwdep_proc_entry;
 506
 507 static void __init snd_hwdep_proc_init(void)
 508 {
 509         struct snd_info_entry *entry;
 510
 511         if ((entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL)) != NULL) {
 512                 entry->c.text.read = snd_hwdep_proc_read;
 513                 if (snd_info_register(entry) < 0) {
 514                         snd_info_free_entry(entry);
 515                         entry = NULL;
 516                 }
 517         }
 518         snd_hwdep_proc_entry = entry;
 519 }
 520
 521 static void __exit snd_hwdep_proc_done(void)
 522 {
 523         snd_info_free_entry(snd_hwdep_proc_entry);
 524 }
 525 #else /* !CONFIG_SND_PROC_FS */
 526 #define snd_hwdep_proc_init()
 527 #define snd_hwdep_proc_done()
 528 #endif /* CONFIG_SND_PROC_FS */
 529
 530
 531 /*
 532  *  ENTRY functions
 533  */
 534
 535 static int __init alsa_hwdep_init(void)
 536 {
 537         snd_hwdep_proc_init();
 538         snd_ctl_register_ioctl(snd_hwdep_control_ioctl);
 539         snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
 540         return 0;
 541 }
 542
 543 static void __exit alsa_hwdep_exit(void)
 544 {
 545         snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl);
 546         snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl);
 547         snd_hwdep_proc_done();
 548 }
 549
 550 module_init(alsa_hwdep_init)
 551 module_exit(alsa_hwdep_exit)