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 snd_hwdep_search(struct snd_card * card,int device)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 snd_hwdep_llseek(struct file * file,loff_t offset,int orig)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 snd_hwdep_read(struct file * file,char __user * buf,size_t count,loff_t * offset)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 snd_hwdep_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)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 snd_hwdep_open(struct inode * inode,struct file * file)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 snd_hwdep_release(struct inode * inode,struct file * file)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 snd_hwdep_poll(struct file * file,poll_table * wait)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 snd_hwdep_info(struct snd_hwdep * hw,struct snd_hwdep_info __user * _info)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 snd_hwdep_dsp_status(struct snd_hwdep * hw,struct snd_hwdep_dsp_status __user * _info)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 snd_hwdep_dsp_load(struct snd_hwdep * hw,struct snd_hwdep_dsp_image * info)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 snd_hwdep_dsp_load_user(struct snd_hwdep * hw,struct snd_hwdep_dsp_image __user * _info)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 snd_hwdep_ioctl(struct file * file,unsigned int cmd,unsigned long arg)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 snd_hwdep_mmap(struct file * file,struct vm_area_struct * vma)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 snd_hwdep_control_ioctl(struct snd_card * card,struct snd_ctl_file * control,unsigned int cmd,unsigned long arg)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, ®ister_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, ®ister_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 snd_hwdep_free(struct snd_hwdep * hwdep)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 */ snd_hwdep_new(struct snd_card * card,char * id,int device,struct snd_hwdep ** rhwdep)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 snd_hwdep_dev_free(struct snd_device * device)412 static int snd_hwdep_dev_free(struct snd_device *device) 413 { 414 snd_hwdep_free(device->device_data); 415 return 0; 416 } 417 snd_hwdep_dev_register(struct snd_device * device)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)(®ister_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 snd_hwdep_dev_disconnect(struct snd_device * device)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)(®ister_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 snd_hwdep_proc_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)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)(®ister_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 snd_hwdep_proc_init(void)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 snd_hwdep_proc_done(void)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 alsa_hwdep_init(void)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 alsa_hwdep_exit(void)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) 540