1/*
2 *  Advanced Linux Sound Architecture
3 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 *
5 *
6 *   This program is free software; you can redistribute it and/or modify
7 *   it under the terms of the GNU General Public License as published by
8 *   the Free Software Foundation; either version 2 of the License, or
9 *   (at your option) any later version.
10 *
11 *   This program is distributed in the hope that it will be useful,
12 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 *   GNU General Public License for more details.
15 *
16 *   You should have received a copy of the GNU General Public License
17 *   along with this program; if not, write to the Free Software
18 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19 *
20 */
21
22#include <linux/init.h>
23#include <linux/slab.h>
24#include <linux/smp_lock.h>
25#include <linux/time.h>
26#include <linux/device.h>
27#include <linux/moduleparam.h>
28#include <sound/core.h>
29#include <sound/minors.h>
30#include <sound/info.h>
31#include <sound/version.h>
32#include <sound/control.h>
33#include <sound/initval.h>
34#include <linux/kmod.h>
35#include <linux/mutex.h>
36
37static int major = CONFIG_SND_MAJOR;
38int snd_major;
39EXPORT_SYMBOL(snd_major);
40
41static int cards_limit = 1;
42
43MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
44MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
45MODULE_LICENSE("GPL");
46module_param(major, int, 0444);
47MODULE_PARM_DESC(major, "Major # for sound driver.");
48module_param(cards_limit, int, 0444);
49MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
50MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
51
52/* this one holds the actual max. card number currently available.
53 * as default, it's identical with cards_limit option.  when more
54 * modules are loaded manually, this limit number increases, too.
55 */
56int snd_ecards_limit;
57EXPORT_SYMBOL(snd_ecards_limit);
58
59static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
60static DEFINE_MUTEX(sound_mutex);
61
62#ifdef CONFIG_MODULES
63
64/**
65 * snd_request_card - try to load the card module
66 * @card: the card number
67 *
68 * Tries to load the module "snd-card-X" for the given card number
69 * via request_module.  Returns immediately if already loaded.
70 */
71void snd_request_card(int card)
72{
73	if (snd_card_locked(card))
74		return;
75	if (card < 0 || card >= cards_limit)
76		return;
77	request_module("snd-card-%i", card);
78}
79
80EXPORT_SYMBOL(snd_request_card);
81
82static void snd_request_other(int minor)
83{
84	char *str;
85
86	switch (minor) {
87	case SNDRV_MINOR_SEQUENCER:	str = "snd-seq";	break;
88	case SNDRV_MINOR_TIMER:		str = "snd-timer";	break;
89	default:			return;
90	}
91	request_module(str);
92}
93
94#endif	/* modular kernel */
95
96/**
97 * snd_lookup_minor_data - get user data of a registered device
98 * @minor: the minor number
99 * @type: device type (SNDRV_DEVICE_TYPE_XXX)
100 *
101 * Checks that a minor device with the specified type is registered, and returns
102 * its user data pointer.
103 */
104void *snd_lookup_minor_data(unsigned int minor, int type)
105{
106	struct snd_minor *mreg;
107	void *private_data;
108
109	if (minor >= ARRAY_SIZE(snd_minors))
110		return NULL;
111	mutex_lock(&sound_mutex);
112	mreg = snd_minors[minor];
113	if (mreg && mreg->type == type)
114		private_data = mreg->private_data;
115	else
116		private_data = NULL;
117	mutex_unlock(&sound_mutex);
118	return private_data;
119}
120
121EXPORT_SYMBOL(snd_lookup_minor_data);
122
123#ifdef CONFIG_MODULES
124static struct snd_minor *autoload_device(unsigned int minor)
125{
126	int dev;
127	mutex_unlock(&sound_mutex); /* release lock temporarily */
128	dev = SNDRV_MINOR_DEVICE(minor);
129	if (dev == SNDRV_MINOR_CONTROL) {
130		/* /dev/aloadC? */
131		int card = SNDRV_MINOR_CARD(minor);
132		if (snd_cards[card] == NULL)
133			snd_request_card(card);
134	} else if (dev == SNDRV_MINOR_GLOBAL) {
135		/* /dev/aloadSEQ */
136		snd_request_other(minor);
137	}
138	mutex_lock(&sound_mutex); /* reacuire lock */
139	return snd_minors[minor];
140}
141#else /* !CONFIG_MODULES */
142#define autoload_device(minor)	NULL
143#endif /* CONFIG_MODULES */
144
145static int snd_open(struct inode *inode, struct file *file)
146{
147	unsigned int minor = iminor(inode);
148	struct snd_minor *mptr = NULL;
149	const struct file_operations *old_fops;
150	int err = 0;
151
152	if (minor >= ARRAY_SIZE(snd_minors))
153		return -ENODEV;
154	mutex_lock(&sound_mutex);
155	mptr = snd_minors[minor];
156	if (mptr == NULL) {
157		mptr = autoload_device(minor);
158		if (!mptr) {
159			mutex_unlock(&sound_mutex);
160			return -ENODEV;
161		}
162	}
163	old_fops = file->f_op;
164	file->f_op = fops_get(mptr->f_ops);
165	if (file->f_op == NULL) {
166		file->f_op = old_fops;
167		err = -ENODEV;
168	}
169	mutex_unlock(&sound_mutex);
170	if (err < 0)
171		return err;
172
173	if (file->f_op->open) {
174		err = file->f_op->open(inode, file);
175		if (err) {
176			fops_put(file->f_op);
177			file->f_op = fops_get(old_fops);
178		}
179	}
180	fops_put(old_fops);
181	return err;
182}
183
184static const struct file_operations snd_fops =
185{
186	.owner =	THIS_MODULE,
187	.open =		snd_open
188};
189
190#ifdef CONFIG_SND_DYNAMIC_MINORS
191static int snd_find_free_minor(void)
192{
193	int minor;
194
195	for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
196		/* skip minors still used statically for autoloading devices */
197		if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL ||
198		    minor == SNDRV_MINOR_SEQUENCER)
199			continue;
200		if (!snd_minors[minor])
201			return minor;
202	}
203	return -EBUSY;
204}
205#else
206static int snd_kernel_minor(int type, struct snd_card *card, int dev)
207{
208	int minor;
209
210	switch (type) {
211	case SNDRV_DEVICE_TYPE_SEQUENCER:
212	case SNDRV_DEVICE_TYPE_TIMER:
213		minor = type;
214		break;
215	case SNDRV_DEVICE_TYPE_CONTROL:
216		if (snd_BUG_ON(!card))
217			return -EINVAL;
218		minor = SNDRV_MINOR(card->number, type);
219		break;
220	case SNDRV_DEVICE_TYPE_HWDEP:
221	case SNDRV_DEVICE_TYPE_RAWMIDI:
222	case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
223	case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
224		if (snd_BUG_ON(!card))
225			return -EINVAL;
226		minor = SNDRV_MINOR(card->number, type + dev);
227		break;
228	default:
229		return -EINVAL;
230	}
231	if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
232		return -EINVAL;
233	return minor;
234}
235#endif
236
237/**
238 * snd_register_device_for_dev - Register the ALSA device file for the card
239 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
240 * @card: the card instance
241 * @dev: the device index
242 * @f_ops: the file operations
243 * @private_data: user pointer for f_ops->open()
244 * @name: the device file name
245 * @device: the &struct device to link this new device to
246 *
247 * Registers an ALSA device file for the given card.
248 * The operators have to be set in reg parameter.
249 *
250 * Returns zero if successful, or a negative error code on failure.
251 */
252int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
253				const struct file_operations *f_ops,
254				void *private_data,
255				const char *name, struct device *device)
256{
257	int minor;
258	struct snd_minor *preg;
259
260	if (snd_BUG_ON(!name))
261		return -EINVAL;
262	preg = kmalloc(sizeof *preg, GFP_KERNEL);
263	if (preg == NULL)
264		return -ENOMEM;
265	preg->type = type;
266	preg->card = card ? card->number : -1;
267	preg->device = dev;
268	preg->f_ops = f_ops;
269	preg->private_data = private_data;
270	mutex_lock(&sound_mutex);
271#ifdef CONFIG_SND_DYNAMIC_MINORS
272	minor = snd_find_free_minor();
273#else
274	minor = snd_kernel_minor(type, card, dev);
275	if (minor >= 0 && snd_minors[minor])
276		minor = -EBUSY;
277#endif
278	if (minor < 0) {
279		mutex_unlock(&sound_mutex);
280		kfree(preg);
281		return minor;
282	}
283	snd_minors[minor] = preg;
284	preg->dev = device_create(sound_class, device, MKDEV(major, minor),
285				  private_data, "%s", name);
286	if (IS_ERR(preg->dev)) {
287		snd_minors[minor] = NULL;
288		mutex_unlock(&sound_mutex);
289		minor = PTR_ERR(preg->dev);
290		kfree(preg);
291		return minor;
292	}
293
294	mutex_unlock(&sound_mutex);
295	return 0;
296}
297
298EXPORT_SYMBOL(snd_register_device_for_dev);
299
300/* find the matching minor record
301 * return the index of snd_minor, or -1 if not found
302 */
303static int find_snd_minor(int type, struct snd_card *card, int dev)
304{
305	int cardnum, minor;
306	struct snd_minor *mptr;
307
308	cardnum = card ? card->number : -1;
309	for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
310		if ((mptr = snd_minors[minor]) != NULL &&
311		    mptr->type == type &&
312		    mptr->card == cardnum &&
313		    mptr->device == dev)
314			return minor;
315	return -1;
316}
317
318/**
319 * snd_unregister_device - unregister the device on the given card
320 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
321 * @card: the card instance
322 * @dev: the device index
323 *
324 * Unregisters the device file already registered via
325 * snd_register_device().
326 *
327 * Returns zero if sucecessful, or a negative error code on failure
328 */
329int snd_unregister_device(int type, struct snd_card *card, int dev)
330{
331	int minor;
332
333	mutex_lock(&sound_mutex);
334	minor = find_snd_minor(type, card, dev);
335	if (minor < 0) {
336		mutex_unlock(&sound_mutex);
337		return -EINVAL;
338	}
339
340	device_destroy(sound_class, MKDEV(major, minor));
341
342	kfree(snd_minors[minor]);
343	snd_minors[minor] = NULL;
344	mutex_unlock(&sound_mutex);
345	return 0;
346}
347
348EXPORT_SYMBOL(snd_unregister_device);
349
350int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
351			      struct device_attribute *attr)
352{
353	int minor, ret = -EINVAL;
354	struct device *d;
355
356	mutex_lock(&sound_mutex);
357	minor = find_snd_minor(type, card, dev);
358	if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL)
359		ret = device_create_file(d, attr);
360	mutex_unlock(&sound_mutex);
361	return ret;
362
363}
364
365EXPORT_SYMBOL(snd_add_device_sysfs_file);
366
367#ifdef CONFIG_PROC_FS
368/*
369 *  INFO PART
370 */
371
372static struct snd_info_entry *snd_minor_info_entry;
373
374static const char *snd_device_type_name(int type)
375{
376	switch (type) {
377	case SNDRV_DEVICE_TYPE_CONTROL:
378		return "control";
379	case SNDRV_DEVICE_TYPE_HWDEP:
380		return "hardware dependent";
381	case SNDRV_DEVICE_TYPE_RAWMIDI:
382		return "raw midi";
383	case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
384		return "digital audio playback";
385	case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
386		return "digital audio capture";
387	case SNDRV_DEVICE_TYPE_SEQUENCER:
388		return "sequencer";
389	case SNDRV_DEVICE_TYPE_TIMER:
390		return "timer";
391	default:
392		return "?";
393	}
394}
395
396static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
397{
398	int minor;
399	struct snd_minor *mptr;
400
401	mutex_lock(&sound_mutex);
402	for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
403		if (!(mptr = snd_minors[minor]))
404			continue;
405		if (mptr->card >= 0) {
406			if (mptr->device >= 0)
407				snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
408					    minor, mptr->card, mptr->device,
409					    snd_device_type_name(mptr->type));
410			else
411				snd_iprintf(buffer, "%3i: [%2i]   : %s\n",
412					    minor, mptr->card,
413					    snd_device_type_name(mptr->type));
414		} else
415			snd_iprintf(buffer, "%3i:        : %s\n", minor,
416				    snd_device_type_name(mptr->type));
417	}
418	mutex_unlock(&sound_mutex);
419}
420
421int __init snd_minor_info_init(void)
422{
423	struct snd_info_entry *entry;
424
425	entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
426	if (entry) {
427		entry->c.text.read = snd_minor_info_read;
428		if (snd_info_register(entry) < 0) {
429			snd_info_free_entry(entry);
430			entry = NULL;
431		}
432	}
433	snd_minor_info_entry = entry;
434	return 0;
435}
436
437int __exit snd_minor_info_done(void)
438{
439	snd_info_free_entry(snd_minor_info_entry);
440	return 0;
441}
442#endif /* CONFIG_PROC_FS */
443
444/*
445 *  INIT PART
446 */
447
448static int __init alsa_sound_init(void)
449{
450	snd_major = major;
451	snd_ecards_limit = cards_limit;
452	if (register_chrdev(major, "alsa", &snd_fops)) {
453		snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
454		return -EIO;
455	}
456	if (snd_info_init() < 0) {
457		unregister_chrdev(major, "alsa");
458		return -ENOMEM;
459	}
460	snd_info_minor_register();
461#ifndef MODULE
462	printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
463#endif
464	return 0;
465}
466
467static void __exit alsa_sound_exit(void)
468{
469	snd_info_minor_unregister();
470	snd_info_done();
471	unregister_chrdev(major, "alsa");
472}
473
474subsys_initcall(alsa_sound_init);
475module_exit(alsa_sound_exit);
476