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 strlcpy(info.id, hw->id, sizeof(info.id)); 181 strlcpy(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 if ((err = hw->ops.dsp_status(hw, &info)) < 0) 199 return err; 200 if (copy_to_user(_info, &info, sizeof(info))) 201 return -EFAULT; 202 return 0; 203 } 204 205 static int snd_hwdep_dsp_load(struct snd_hwdep *hw, 206 struct snd_hwdep_dsp_image __user *_info) 207 { 208 struct snd_hwdep_dsp_image info; 209 int err; 210 211 if (! hw->ops.dsp_load) 212 return -ENXIO; 213 memset(&info, 0, sizeof(info)); 214 if (copy_from_user(&info, _info, sizeof(info))) 215 return -EFAULT; 216 if (info.index >= 32) 217 return -EINVAL; 218 /* check whether the dsp was already loaded */ 219 if (hw->dsp_loaded & (1u << info.index)) 220 return -EBUSY; 221 err = hw->ops.dsp_load(hw, &info); 222 if (err < 0) 223 return err; 224 hw->dsp_loaded |= (1u << info.index); 225 return 0; 226 } 227 228 static long snd_hwdep_ioctl(struct file * file, unsigned int cmd, 229 unsigned long arg) 230 { 231 struct snd_hwdep *hw = file->private_data; 232 void __user *argp = (void __user *)arg; 233 switch (cmd) { 234 case SNDRV_HWDEP_IOCTL_PVERSION: 235 return put_user(SNDRV_HWDEP_VERSION, (int __user *)argp); 236 case SNDRV_HWDEP_IOCTL_INFO: 237 return snd_hwdep_info(hw, argp); 238 case SNDRV_HWDEP_IOCTL_DSP_STATUS: 239 return snd_hwdep_dsp_status(hw, argp); 240 case SNDRV_HWDEP_IOCTL_DSP_LOAD: 241 return snd_hwdep_dsp_load(hw, argp); 242 } 243 if (hw->ops.ioctl) 244 return hw->ops.ioctl(hw, file, cmd, arg); 245 return -ENOTTY; 246 } 247 248 static int snd_hwdep_mmap(struct file * file, struct vm_area_struct * vma) 249 { 250 struct snd_hwdep *hw = file->private_data; 251 if (hw->ops.mmap) 252 return hw->ops.mmap(hw, file, vma); 253 return -ENXIO; 254 } 255 256 static int snd_hwdep_control_ioctl(struct snd_card *card, 257 struct snd_ctl_file * control, 258 unsigned int cmd, unsigned long arg) 259 { 260 switch (cmd) { 261 case SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE: 262 { 263 int device; 264 265 if (get_user(device, (int __user *)arg)) 266 return -EFAULT; 267 mutex_lock(®ister_mutex); 268 269 if (device < 0) 270 device = 0; 271 else if (device < SNDRV_MINOR_HWDEPS) 272 device++; 273 else 274 device = SNDRV_MINOR_HWDEPS; 275 276 while (device < SNDRV_MINOR_HWDEPS) { 277 if (snd_hwdep_search(card, device)) 278 break; 279 device++; 280 } 281 if (device >= SNDRV_MINOR_HWDEPS) 282 device = -1; 283 mutex_unlock(®ister_mutex); 284 if (put_user(device, (int __user *)arg)) 285 return -EFAULT; 286 return 0; 287 } 288 case SNDRV_CTL_IOCTL_HWDEP_INFO: 289 { 290 struct snd_hwdep_info __user *info = (struct snd_hwdep_info __user *)arg; 291 int device, err; 292 struct snd_hwdep *hwdep; 293 294 if (get_user(device, &info->device)) 295 return -EFAULT; 296 mutex_lock(®ister_mutex); 297 hwdep = snd_hwdep_search(card, device); 298 if (hwdep) 299 err = snd_hwdep_info(hwdep, info); 300 else 301 err = -ENXIO; 302 mutex_unlock(®ister_mutex); 303 return err; 304 } 305 } 306 return -ENOIOCTLCMD; 307 } 308 309 #ifdef CONFIG_COMPAT 310 #include "hwdep_compat.c" 311 #else 312 #define snd_hwdep_ioctl_compat NULL 313 #endif 314 315 /* 316 317 */ 318 319 static const struct file_operations snd_hwdep_f_ops = 320 { 321 .owner = THIS_MODULE, 322 .llseek = snd_hwdep_llseek, 323 .read = snd_hwdep_read, 324 .write = snd_hwdep_write, 325 .open = snd_hwdep_open, 326 .release = snd_hwdep_release, 327 .poll = snd_hwdep_poll, 328 .unlocked_ioctl = snd_hwdep_ioctl, 329 .compat_ioctl = snd_hwdep_ioctl_compat, 330 .mmap = snd_hwdep_mmap, 331 }; 332 333 static void release_hwdep_device(struct device *dev) 334 { 335 kfree(container_of(dev, struct snd_hwdep, dev)); 336 } 337 338 /** 339 * snd_hwdep_new - create a new hwdep instance 340 * @card: the card instance 341 * @id: the id string 342 * @device: the device index (zero-based) 343 * @rhwdep: the pointer to store the new hwdep instance 344 * 345 * Creates a new hwdep instance with the given index on the card. 346 * The callbacks (hwdep->ops) must be set on the returned instance 347 * after this call manually by the caller. 348 * 349 * Return: Zero if successful, or a negative error code on failure. 350 */ 351 int snd_hwdep_new(struct snd_card *card, char *id, int device, 352 struct snd_hwdep **rhwdep) 353 { 354 struct snd_hwdep *hwdep; 355 int err; 356 static const struct snd_device_ops ops = { 357 .dev_free = snd_hwdep_dev_free, 358 .dev_register = snd_hwdep_dev_register, 359 .dev_disconnect = snd_hwdep_dev_disconnect, 360 }; 361 362 if (snd_BUG_ON(!card)) 363 return -ENXIO; 364 if (rhwdep) 365 *rhwdep = NULL; 366 hwdep = kzalloc(sizeof(*hwdep), GFP_KERNEL); 367 if (!hwdep) 368 return -ENOMEM; 369 370 init_waitqueue_head(&hwdep->open_wait); 371 mutex_init(&hwdep->open_mutex); 372 hwdep->card = card; 373 hwdep->device = device; 374 if (id) 375 strlcpy(hwdep->id, id, sizeof(hwdep->id)); 376 377 snd_device_initialize(&hwdep->dev, card); 378 hwdep->dev.release = release_hwdep_device; 379 dev_set_name(&hwdep->dev, "hwC%iD%i", card->number, device); 380 #ifdef CONFIG_SND_OSSEMUL 381 hwdep->oss_type = -1; 382 #endif 383 384 err = snd_device_new(card, SNDRV_DEV_HWDEP, hwdep, &ops); 385 if (err < 0) { 386 put_device(&hwdep->dev); 387 return err; 388 } 389 390 if (rhwdep) 391 *rhwdep = hwdep; 392 return 0; 393 } 394 EXPORT_SYMBOL(snd_hwdep_new); 395 396 static int snd_hwdep_dev_free(struct snd_device *device) 397 { 398 struct snd_hwdep *hwdep = device->device_data; 399 if (!hwdep) 400 return 0; 401 if (hwdep->private_free) 402 hwdep->private_free(hwdep); 403 put_device(&hwdep->dev); 404 return 0; 405 } 406 407 static int snd_hwdep_dev_register(struct snd_device *device) 408 { 409 struct snd_hwdep *hwdep = device->device_data; 410 struct snd_card *card = hwdep->card; 411 int err; 412 413 mutex_lock(®ister_mutex); 414 if (snd_hwdep_search(card, hwdep->device)) { 415 mutex_unlock(®ister_mutex); 416 return -EBUSY; 417 } 418 list_add_tail(&hwdep->list, &snd_hwdep_devices); 419 err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP, 420 hwdep->card, hwdep->device, 421 &snd_hwdep_f_ops, hwdep, &hwdep->dev); 422 if (err < 0) { 423 dev_err(&hwdep->dev, "unable to register\n"); 424 list_del(&hwdep->list); 425 mutex_unlock(®ister_mutex); 426 return err; 427 } 428 429 #ifdef CONFIG_SND_OSSEMUL 430 hwdep->ossreg = 0; 431 if (hwdep->oss_type >= 0) { 432 if (hwdep->oss_type == SNDRV_OSS_DEVICE_TYPE_DMFM && 433 hwdep->device) 434 dev_warn(&hwdep->dev, 435 "only hwdep device 0 can be registered as OSS direct FM device!\n"); 436 else if (snd_register_oss_device(hwdep->oss_type, 437 card, hwdep->device, 438 &snd_hwdep_f_ops, hwdep) < 0) 439 dev_warn(&hwdep->dev, 440 "unable to register OSS compatibility device\n"); 441 else 442 hwdep->ossreg = 1; 443 } 444 #endif 445 mutex_unlock(®ister_mutex); 446 return 0; 447 } 448 449 static int snd_hwdep_dev_disconnect(struct snd_device *device) 450 { 451 struct snd_hwdep *hwdep = device->device_data; 452 453 if (snd_BUG_ON(!hwdep)) 454 return -ENXIO; 455 mutex_lock(®ister_mutex); 456 if (snd_hwdep_search(hwdep->card, hwdep->device) != hwdep) { 457 mutex_unlock(®ister_mutex); 458 return -EINVAL; 459 } 460 mutex_lock(&hwdep->open_mutex); 461 wake_up(&hwdep->open_wait); 462 #ifdef CONFIG_SND_OSSEMUL 463 if (hwdep->ossreg) 464 snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device); 465 #endif 466 snd_unregister_device(&hwdep->dev); 467 list_del_init(&hwdep->list); 468 mutex_unlock(&hwdep->open_mutex); 469 mutex_unlock(®ister_mutex); 470 return 0; 471 } 472 473 #ifdef CONFIG_SND_PROC_FS 474 /* 475 * Info interface 476 */ 477 478 static void snd_hwdep_proc_read(struct snd_info_entry *entry, 479 struct snd_info_buffer *buffer) 480 { 481 struct snd_hwdep *hwdep; 482 483 mutex_lock(®ister_mutex); 484 list_for_each_entry(hwdep, &snd_hwdep_devices, list) 485 snd_iprintf(buffer, "%02i-%02i: %s\n", 486 hwdep->card->number, hwdep->device, hwdep->name); 487 mutex_unlock(®ister_mutex); 488 } 489 490 static struct snd_info_entry *snd_hwdep_proc_entry; 491 492 static void __init snd_hwdep_proc_init(void) 493 { 494 struct snd_info_entry *entry; 495 496 if ((entry = snd_info_create_module_entry(THIS_MODULE, "hwdep", NULL)) != NULL) { 497 entry->c.text.read = snd_hwdep_proc_read; 498 if (snd_info_register(entry) < 0) { 499 snd_info_free_entry(entry); 500 entry = NULL; 501 } 502 } 503 snd_hwdep_proc_entry = entry; 504 } 505 506 static void __exit snd_hwdep_proc_done(void) 507 { 508 snd_info_free_entry(snd_hwdep_proc_entry); 509 } 510 #else /* !CONFIG_SND_PROC_FS */ 511 #define snd_hwdep_proc_init() 512 #define snd_hwdep_proc_done() 513 #endif /* CONFIG_SND_PROC_FS */ 514 515 516 /* 517 * ENTRY functions 518 */ 519 520 static int __init alsa_hwdep_init(void) 521 { 522 snd_hwdep_proc_init(); 523 snd_ctl_register_ioctl(snd_hwdep_control_ioctl); 524 snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl); 525 return 0; 526 } 527 528 static void __exit alsa_hwdep_exit(void) 529 { 530 snd_ctl_unregister_ioctl(snd_hwdep_control_ioctl); 531 snd_ctl_unregister_ioctl_compat(snd_hwdep_control_ioctl); 532 snd_hwdep_proc_done(); 533 } 534 535 module_init(alsa_hwdep_init) 536 module_exit(alsa_hwdep_exit) 537