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(®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 }; 340 341 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(®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 } 456 457 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 */ 485 486 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; 499 500 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) 546