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
20MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
21MODULE_DESCRIPTION("Hardware dependent layer");
22MODULE_LICENSE("GPL");
23
24static LIST_HEAD(snd_hwdep_devices);
25static DEFINE_MUTEX(register_mutex);
26
27static int snd_hwdep_dev_free(struct snd_device *device);
28static int snd_hwdep_dev_register(struct snd_device *device);
29static int snd_hwdep_dev_disconnect(struct snd_device *device);
30
31
32static 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
42static 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
50static 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
59static 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
68static 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(minor: 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(module: hw->card->module)) {
89 snd_card_unref(card: hw->card);
90 return -EFAULT;
91 }
92
93 init_waitqueue_entry(wq_entry: &wait, current);
94 add_wait_queue(wq_head: &hw->open_wait, wq_entry: &wait);
95 mutex_lock(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(lock: &hw->open_mutex);
117 schedule();
118 mutex_lock(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(wq_head: &hw->open_wait, wq_entry: &wait);
129 if (err >= 0) {
130 err = snd_card_file_add(card: 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(lock: &hw->open_mutex);
140 if (err < 0)
141 module_put(module: hw->card->module);
142 snd_card_unref(card: hw->card);
143 return err;
144}
145
146static 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(card: hw->card, file);
161 module_put(module: mod);
162 return err;
163}
164
165static __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
173static 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(s: &info, c: 0, n: 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(to: _info, from: &info, n: sizeof(info)))
184 return -EFAULT;
185 return 0;
186}
187
188static 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(s: &info, c: 0, n: 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(to: _info, from: &info, n: sizeof(info)))
202 return -EFAULT;
203 return 0;
204}
205
206static 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
225static 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(to: &info, from: _info, n: sizeof(info)))
231 return -EFAULT;
232 return snd_hwdep_dsp_load(hw, info: &info);
233}
234
235
236static 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, info: argp);
246 case SNDRV_HWDEP_IOCTL_DSP_STATUS:
247 return snd_hwdep_dsp_status(hw, info: argp);
248 case SNDRV_HWDEP_IOCTL_DSP_LOAD:
249 return snd_hwdep_dsp_load_user(hw, info: argp);
250 }
251 if (hw->ops.ioctl)
252 return hw->ops.ioctl(hw, file, cmd, arg);
253 return -ENOTTY;
254}
255
256static 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
264static 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(hw: hwdep, info: 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
326static 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
340static 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(dev: hwdep->dev);
347 kfree(objp: 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 */
363int 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(dev_p: &hwdep->dev, card);
390 if (err < 0) {
391 snd_hwdep_free(hwdep);
392 return err;
393 }
394
395 dev_set_name(dev: hwdep->dev, name: "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, type: SNDRV_DEV_HWDEP, device_data: hwdep, ops: &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}
410EXPORT_SYMBOL(snd_hwdep_new);
411
412static int snd_hwdep_dev_free(struct snd_device *device)
413{
414 snd_hwdep_free(hwdep: device->device_data);
415 return 0;
416}
417
418static 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)(T: &register_mutex);
425 if (snd_hwdep_search(card, device: hwdep->device))
426 return -EBUSY;
427 list_add_tail(new: &hwdep->list, head: &snd_hwdep_devices);
428 err = snd_register_device(SNDRV_DEVICE_TYPE_HWDEP,
429 card: hwdep->card, dev: hwdep->device,
430 f_ops: &snd_hwdep_f_ops, private_data: hwdep, device: hwdep->dev);
431 if (err < 0) {
432 dev_err(hwdep->dev, "unable to register\n");
433 list_del(entry: &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
456static 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)(T: &register_mutex);
463 if (snd_hwdep_search(card: hwdep->card, device: hwdep->device) != hwdep)
464 return -EINVAL;
465 guard(mutex)(T: &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(dev: hwdep->dev);
472 list_del_init(entry: &hwdep->list);
473 return 0;
474}
475
476#ifdef CONFIG_SND_PROC_FS
477/*
478 * Info interface
479 */
480
481static 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)(T: &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
492static struct snd_info_entry *snd_hwdep_proc_entry;
493
494static void __init snd_hwdep_proc_init(void)
495{
496 struct snd_info_entry *entry;
497
498 entry = snd_info_create_module_entry(THIS_MODULE, name: "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
509static void __exit snd_hwdep_proc_done(void)
510{
511 snd_info_free_entry(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
523static int __init alsa_hwdep_init(void)
524{
525 snd_hwdep_proc_init();
526 snd_ctl_register_ioctl(fcn: snd_hwdep_control_ioctl);
527 snd_ctl_register_ioctl_compat(fcn: snd_hwdep_control_ioctl);
528 return 0;
529}
530
531static void __exit alsa_hwdep_exit(void)
532{
533 snd_ctl_unregister_ioctl(fcn: snd_hwdep_control_ioctl);
534 snd_ctl_unregister_ioctl_compat(fcn: snd_hwdep_control_ioctl);
535 snd_hwdep_proc_done();
536}
537
538module_init(alsa_hwdep_init)
539module_exit(alsa_hwdep_exit)
540