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(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
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(hw->card, file);
161	module_put(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(&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
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(&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
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(&info, _info, sizeof(info)))
231		return -EFAULT;
232	return snd_hwdep_dsp_load(hw, &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, 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
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(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
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(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 */
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(&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}
410EXPORT_SYMBOL(snd_hwdep_new);
411
412static int snd_hwdep_dev_free(struct snd_device *device)
413{
414	snd_hwdep_free(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)(&register_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
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)(&register_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
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)(&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, "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(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(snd_hwdep_control_ioctl);
527	snd_ctl_register_ioctl_compat(snd_hwdep_control_ioctl);
528	return 0;
529}
530
531static 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
538module_init(alsa_hwdep_init)
539module_exit(alsa_hwdep_exit)
540