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