[mirror_ubuntu-jammy-kernel.git] / sound / core / sound.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Advanced Linux Sound Architecture
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/debugfs.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/info.h>
#include <sound/control.h>
#include <sound/initval.h>
#include <linux/kmod.h>
#include <linux/mutex.h>

static int major = CONFIG_SND_MAJOR;
int snd_major;
EXPORT_SYMBOL(snd_major);

static int cards_limit = 1;

MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
MODULE_LICENSE("GPL");
module_param(major, int, 0444);
MODULE_PARM_DESC(major, "Major # for sound driver.");
module_param(cards_limit, int, 0444);
MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);

/* this one holds the actual max. card number currently available.
 * as default, it's identical with cards_limit option.  when more
 * modules are loaded manually, this limit number increases, too.
 */
int snd_ecards_limit;
EXPORT_SYMBOL(snd_ecards_limit);

#ifdef CONFIG_SND_DEBUG
struct dentry *sound_debugfs_root;
EXPORT_SYMBOL_GPL(sound_debugfs_root);
#endif

static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
static DEFINE_MUTEX(sound_mutex);

#ifdef CONFIG_MODULES

/**
 * snd_request_card - try to load the card module
 * @card: the card number
 *
 * Tries to load the module "snd-card-X" for the given card number
 * via request_module.  Returns immediately if already loaded.
 */
void snd_request_card(int card)
{
	if (snd_card_locked(card))
		return;
	if (card < 0 || card >= cards_limit)
		return;
	request_module("snd-card-%i", card);
}
EXPORT_SYMBOL(snd_request_card);

static void snd_request_other(int minor)
{
	char *str;

	switch (minor) {
	case SNDRV_MINOR_SEQUENCER:	str = "snd-seq";	break;
	case SNDRV_MINOR_TIMER:		str = "snd-timer";	break;
	default:			return;
	}
	request_module(str);
}

#endif	/* modular kernel */

/**
 * snd_lookup_minor_data - get user data of a registered device
 * @minor: the minor number
 * @type: device type (SNDRV_DEVICE_TYPE_XXX)
 *
 * Checks that a minor device with the specified type is registered, and returns
 * its user data pointer.
 *
 * This function increments the reference counter of the card instance
 * if an associated instance with the given minor number and type is found.
 * The caller must call snd_card_unref() appropriately later.
 *
 * Return: The user data pointer if the specified device is found. %NULL
 * otherwise.
 */
void *snd_lookup_minor_data(unsigned int minor, int type)
{
	struct snd_minor *mreg;
	void *private_data;

	if (minor >= ARRAY_SIZE(snd_minors))
		return NULL;
	mutex_lock(&sound_mutex);
	mreg = snd_minors[minor];
	if (mreg && mreg->type == type) {
		private_data = mreg->private_data;
		if (private_data && mreg->card_ptr)
			get_device(&mreg->card_ptr->card_dev);
	} else
		private_data = NULL;
	mutex_unlock(&sound_mutex);
	return private_data;
}
EXPORT_SYMBOL(snd_lookup_minor_data);

#ifdef CONFIG_MODULES
static struct snd_minor *autoload_device(unsigned int minor)
{
	int dev;
	mutex_unlock(&sound_mutex); /* release lock temporarily */
	dev = SNDRV_MINOR_DEVICE(minor);
	if (dev == SNDRV_MINOR_CONTROL) {
		/* /dev/aloadC? */
		int card = SNDRV_MINOR_CARD(minor);
		struct snd_card *ref = snd_card_ref(card);
		if (!ref)
			snd_request_card(card);
		else
			snd_card_unref(ref);
	} else if (dev == SNDRV_MINOR_GLOBAL) {
		/* /dev/aloadSEQ */
		snd_request_other(minor);
	}
	mutex_lock(&sound_mutex); /* reacuire lock */
	return snd_minors[minor];
}
#else /* !CONFIG_MODULES */
#define autoload_device(minor)	NULL
#endif /* CONFIG_MODULES */

static int snd_open(struct inode *inode, struct file *file)
{
	unsigned int minor = iminor(inode);
	struct snd_minor *mptr = NULL;
	const struct file_operations *new_fops;
	int err = 0;

	if (minor >= ARRAY_SIZE(snd_minors))
		return -ENODEV;
	mutex_lock(&sound_mutex);
	mptr = snd_minors[minor];
	if (mptr == NULL) {
		mptr = autoload_device(minor);
		if (!mptr) {
			mutex_unlock(&sound_mutex);
			return -ENODEV;
		}
	}
	new_fops = fops_get(mptr->f_ops);
	mutex_unlock(&sound_mutex);
	if (!new_fops)
		return -ENODEV;
	replace_fops(file, new_fops);

	if (file->f_op->open)
		err = file->f_op->open(inode, file);
	return err;
}

static const struct file_operations snd_fops =
{
	.owner =	THIS_MODULE,
	.open =		snd_open,
	.llseek =	noop_llseek,
};

#ifdef CONFIG_SND_DYNAMIC_MINORS
static int snd_find_free_minor(int type, struct snd_card *card, int dev)
{
	int minor;

	/* static minors for module auto loading */
	if (type == SNDRV_DEVICE_TYPE_SEQUENCER)
		return SNDRV_MINOR_SEQUENCER;
	if (type == SNDRV_DEVICE_TYPE_TIMER)
		return SNDRV_MINOR_TIMER;

	for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
		/* skip static minors still used for module auto loading */
		if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL)
			continue;
		if (minor == SNDRV_MINOR_SEQUENCER ||
		    minor == SNDRV_MINOR_TIMER)
			continue;
		if (!snd_minors[minor])
			return minor;
	}
	return -EBUSY;
}
#else
static int snd_find_free_minor(int type, struct snd_card *card, int dev)
{
	int minor;

	switch (type) {
	case SNDRV_DEVICE_TYPE_SEQUENCER:
	case SNDRV_DEVICE_TYPE_TIMER:
		minor = type;
		break;
	case SNDRV_DEVICE_TYPE_CONTROL:
		if (snd_BUG_ON(!card))
			return -EINVAL;
		minor = SNDRV_MINOR(card->number, type);
		break;
	case SNDRV_DEVICE_TYPE_HWDEP:
	case SNDRV_DEVICE_TYPE_RAWMIDI:
	case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
	case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
	case SNDRV_DEVICE_TYPE_COMPRESS:
		if (snd_BUG_ON(!card))
			return -EINVAL;
		minor = SNDRV_MINOR(card->number, type + dev);
		break;
	default:
		return -EINVAL;
	}
	if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
		return -EINVAL;
	if (snd_minors[minor])
		return -EBUSY;
	return minor;
}
#endif

/**
 * snd_register_device - Register the ALSA device file for the card
 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
 * @card: the card instance
 * @dev: the device index
 * @f_ops: the file operations
 * @private_data: user pointer for f_ops->open()
 * @device: the device to register
 *
 * Registers an ALSA device file for the given card.
 * The operators have to be set in reg parameter.
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_register_device(int type, struct snd_card *card, int dev,
			const struct file_operations *f_ops,
			void *private_data, struct device *device)
{
	int minor;
	int err = 0;
	struct snd_minor *preg;

	if (snd_BUG_ON(!device))
		return -EINVAL;

	preg = kmalloc(sizeof *preg, GFP_KERNEL);
	if (preg == NULL)
		return -ENOMEM;
	preg->type = type;
	preg->card = card ? card->number : -1;
	preg->device = dev;
	preg->f_ops = f_ops;
	preg->private_data = private_data;
	preg->card_ptr = card;
	mutex_lock(&sound_mutex);
	minor = snd_find_free_minor(type, card, dev);
	if (minor < 0) {
		err = minor;
		goto error;
	}

	preg->dev = device;
	device->devt = MKDEV(major, minor);
	err = device_add(device);
	if (err < 0)
		goto error;

	snd_minors[minor] = preg;
 error:
	mutex_unlock(&sound_mutex);
	if (err < 0)
		kfree(preg);
	return err;
}
EXPORT_SYMBOL(snd_register_device);

/**
 * snd_unregister_device - unregister the device on the given card
 * @dev: the device instance
 *
 * Unregisters the device file already registered via
 * snd_register_device().
 *
 * Return: Zero if successful, or a negative error code on failure.
 */
int snd_unregister_device(struct device *dev)
{
	int minor;
	struct snd_minor *preg;

	mutex_lock(&sound_mutex);
	for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
		preg = snd_minors[minor];
		if (preg && preg->dev == dev) {
			snd_minors[minor] = NULL;
			device_del(dev);
			kfree(preg);
			break;
		}
	}
	mutex_unlock(&sound_mutex);
	if (minor >= ARRAY_SIZE(snd_minors))
		return -ENOENT;
	return 0;
}
EXPORT_SYMBOL(snd_unregister_device);

#ifdef CONFIG_SND_PROC_FS
/*
 *  INFO PART
 */
static const char *snd_device_type_name(int type)
{
	switch (type) {
	case SNDRV_DEVICE_TYPE_CONTROL:
		return "control";
	case SNDRV_DEVICE_TYPE_HWDEP:
		return "hardware dependent";
	case SNDRV_DEVICE_TYPE_RAWMIDI:
		return "raw midi";
	case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
		return "digital audio playback";
	case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
		return "digital audio capture";
	case SNDRV_DEVICE_TYPE_SEQUENCER:
		return "sequencer";
	case SNDRV_DEVICE_TYPE_TIMER:
		return "timer";
	case SNDRV_DEVICE_TYPE_COMPRESS:
		return "compress";
	default:
		return "?";
	}
}

static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
{
	int minor;
	struct snd_minor *mptr;

	mutex_lock(&sound_mutex);
	for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
		mptr = snd_minors[minor];
		if (!mptr)
			continue;
		if (mptr->card >= 0) {
			if (mptr->device >= 0)
				snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
					    minor, mptr->card, mptr->device,
					    snd_device_type_name(mptr->type));
			else
				snd_iprintf(buffer, "%3i: [%2i]   : %s\n",
					    minor, mptr->card,
					    snd_device_type_name(mptr->type));
		} else
			snd_iprintf(buffer, "%3i:        : %s\n", minor,
				    snd_device_type_name(mptr->type));
	}
	mutex_unlock(&sound_mutex);
}

int __init snd_minor_info_init(void)
{
	struct snd_info_entry *entry;

	entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
	if (!entry)
		return -ENOMEM;
	entry->c.text.read = snd_minor_info_read;
	return snd_info_register(entry); /* freed in error path */
}
#endif /* CONFIG_SND_PROC_FS */

/*
 *  INIT PART
 */

static int __init alsa_sound_init(void)
{
	snd_major = major;
	snd_ecards_limit = cards_limit;
	if (register_chrdev(major, "alsa", &snd_fops)) {
		pr_err("ALSA core: unable to register native major device number %d\n", major);
		return -EIO;
	}
	if (snd_info_init() < 0) {
		unregister_chrdev(major, "alsa");
		return -ENOMEM;
	}

#ifdef CONFIG_SND_DEBUG
	sound_debugfs_root = debugfs_create_dir("sound", NULL);
#endif
#ifndef MODULE
	pr_info("Advanced Linux Sound Architecture Driver Initialized.\n");
#endif
	return 0;
}

static void __exit alsa_sound_exit(void)
{
#ifdef CONFIG_SND_DEBUG
	debugfs_remove(sound_debugfs_root);
#endif
	snd_info_done();
	unregister_chrdev(major, "alsa");
}

subsys_initcall(alsa_sound_init);
module_exit(alsa_sound_exit);
Commit	Line	Data
1a59d1b8	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
1da177e4 LT	3	* Advanced Linux Sound Architecture
c1017a4c	4	* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
1da177e4 LT	5	*/
1da177e4 LT	6
1da177e4 LT	7	#include <linux/init.h>
	8	#include <linux/slab.h>
	9	#include <linux/time.h>
9a1a2a1d	10	#include <linux/device.h>
65a77217	11	#include <linux/module.h>
2d670ea2	12	#include <linux/debugfs.h>
1da177e4 LT	13	#include <sound/core.h>
	14	#include <sound/minors.h>
	15	#include <sound/info.h>
1da177e4 LT	16	#include <sound/control.h>
	17	#include <sound/initval.h>
	18	#include <linux/kmod.h>
1a60d4c5	19	#include <linux/mutex.h>
1da177e4	20
1da177e4 LT	21	static int major = CONFIG_SND_MAJOR;
1da177e4 LT	22	int snd_major;
c0d3fb39 TI	23	EXPORT_SYMBOL(snd_major);
c0d3fb39 TI	24
1da177e4	25	static int cards_limit = 1;
1da177e4	26
c1017a4c	27	MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
1da177e4 LT	28	MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
	29	MODULE_LICENSE("GPL");
	30	module_param(major, int, 0444);
	31	MODULE_PARM_DESC(major, "Major # for sound driver.");
	32	module_param(cards_limit, int, 0444);
	33	MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
1da177e4 LT	34	MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
	35
	36	/* this one holds the actual max. card number currently available.
	37	* as default, it's identical with cards_limit option. when more
	38	* modules are loaded manually, this limit number increases, too.
	39	*/
	40	int snd_ecards_limit;
c0d3fb39	41	EXPORT_SYMBOL(snd_ecards_limit);
1da177e4	42
2d670ea2 HW	43	#ifdef CONFIG_SND_DEBUG
	44	struct dentry *sound_debugfs_root;
	45	EXPORT_SYMBOL_GPL(sound_debugfs_root);
	46	#endif
	47
6983b724	48	static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
1a60d4c5	49	static DEFINE_MUTEX(sound_mutex);
1da177e4	50
ee2da997	51	#ifdef CONFIG_MODULES
1da177e4 LT	52
	53	/**
	54	* snd_request_card - try to load the card module
	55	* @card: the card number
	56	*
	57	* Tries to load the module "snd-card-X" for the given card number
ee2da997	58	* via request_module. Returns immediately if already loaded.
1da177e4 LT	59	*/
	60	void snd_request_card(int card)
	61	{
746df948	62	if (snd_card_locked(card))
1da177e4 LT	63	return;
	64	if (card < 0 \|\| card >= cards_limit)
	65	return;
	66	request_module("snd-card-%i", card);
	67	}
c0d3fb39 TI	68	EXPORT_SYMBOL(snd_request_card);
c0d3fb39 TI	69
1da177e4 LT	70	static void snd_request_other(int minor)
	71	{
	72	char *str;
	73
1da177e4 LT	74	switch (minor) {
	75	case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break;
	76	case SNDRV_MINOR_TIMER: str = "snd-timer"; break;
	77	default: return;
	78	}
	79	request_module(str);
	80	}
	81
ee2da997	82	#endif /* modular kernel */
1da177e4	83
f87135f5 CL	84	/**
	85	* snd_lookup_minor_data - get user data of a registered device
	86	* @minor: the minor number
	87	* @type: device type (SNDRV_DEVICE_TYPE_XXX)
	88	*
	89	* Checks that a minor device with the specified type is registered, and returns
	90	* its user data pointer.
a0830dbd TI	91	*
	92	* This function increments the reference counter of the card instance
	93	* if an associated instance with the given minor number and type is found.
	94	* The caller must call snd_card_unref() appropriately later.
eb7c06e8 YB	95	*
	96	* Return: The user data pointer if the specified device is found. %NULL
	97	* otherwise.
f87135f5 CL	98	*/
	99	void *snd_lookup_minor_data(unsigned int minor, int type)
	100	{
	101	struct snd_minor *mreg;
	102	void *private_data;
	103
3a63e444	104	if (minor >= ARRAY_SIZE(snd_minors))
f87135f5	105	return NULL;
1a60d4c5	106	mutex_lock(&sound_mutex);
f87135f5	107	mreg = snd_minors[minor];
a0830dbd	108	if (mreg && mreg->type == type) {
f87135f5	109	private_data = mreg->private_data;
8bb4d9ce	110	if (private_data && mreg->card_ptr)
f2464064	111	get_device(&mreg->card_ptr->card_dev);
a0830dbd	112	} else
f87135f5	113	private_data = NULL;
1a60d4c5	114	mutex_unlock(&sound_mutex);
f87135f5 CL	115	return private_data;
f87135f5 CL	116	}
c0d3fb39 TI	117	EXPORT_SYMBOL(snd_lookup_minor_data);
c0d3fb39 TI	118
4cf19b84 TI	119	#ifdef CONFIG_MODULES
	120	static struct snd_minor *autoload_device(unsigned int minor)
	121	{
	122	int dev;
	123	mutex_unlock(&sound_mutex); /* release lock temporarily */
	124	dev = SNDRV_MINOR_DEVICE(minor);
	125	if (dev == SNDRV_MINOR_CONTROL) {
	126	/* /dev/aloadC? */
	127	int card = SNDRV_MINOR_CARD(minor);
f4fa9689 TI	128	struct snd_card *ref = snd_card_ref(card);
f4fa9689 TI	129	if (!ref)
4cf19b84	130	snd_request_card(card);
f4fa9689 TI	131	else
f4fa9689 TI	132	snd_card_unref(ref);
4cf19b84 TI	133	} else if (dev == SNDRV_MINOR_GLOBAL) {
	134	/* /dev/aloadSEQ */
	135	snd_request_other(minor);
	136	}
	137	mutex_lock(&sound_mutex); /* reacuire lock */
	138	return snd_minors[minor];
	139	}
	140	#else /* !CONFIG_MODULES */
	141	#define autoload_device(minor) NULL
	142	#endif /* CONFIG_MODULES */
	143
	144	static int snd_open(struct inode inode, struct file file)
1da177e4	145	{
332682b1	146	unsigned int minor = iminor(inode);
512bbd6a	147	struct snd_minor *mptr = NULL;
e84f9e57	148	const struct file_operations *new_fops;
1da177e4 LT	149	int err = 0;
1da177e4 LT	150
3a63e444	151	if (minor >= ARRAY_SIZE(snd_minors))
332682b1	152	return -ENODEV;
4cf19b84	153	mutex_lock(&sound_mutex);
332682b1 CL	154	mptr = snd_minors[minor];
332682b1 CL	155	if (mptr == NULL) {
4cf19b84 TI	156	mptr = autoload_device(minor);
	157	if (!mptr) {
	158	mutex_unlock(&sound_mutex);
332682b1	159	return -ENODEV;
4cf19b84	160	}
1da177e4	161	}
e84f9e57	162	new_fops = fops_get(mptr->f_ops);
4cf19b84	163	mutex_unlock(&sound_mutex);
e84f9e57 AV	164	if (!new_fops)
	165	return -ENODEV;
	166	replace_fops(file, new_fops);
4cf19b84	167
e84f9e57	168	if (file->f_op->open)
1da177e4	169	err = file->f_op->open(inode, file);
1da177e4 LT	170	return err;
	171	}
	172
9c2e08c5	173	static const struct file_operations snd_fops =
1da177e4 LT	174	{
1da177e4 LT	175	.owner = THIS_MODULE,
6038f373 AB	176	.open = snd_open,
6038f373 AB	177	.llseek = noop_llseek,
1da177e4 LT	178	};
1da177e4 LT	179
332682b1	180	#ifdef CONFIG_SND_DYNAMIC_MINORS
38ebb703	181	static int snd_find_free_minor(int type, struct snd_card *card, int dev)
332682b1 CL	182	{
	183	int minor;
	184
03cfe6f5 KS	185	/* static minors for module auto loading */
	186	if (type == SNDRV_DEVICE_TYPE_SEQUENCER)
	187	return SNDRV_MINOR_SEQUENCER;
	188	if (type == SNDRV_DEVICE_TYPE_TIMER)
	189	return SNDRV_MINOR_TIMER;
	190
332682b1	191	for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
03cfe6f5 KS	192	/* skip static minors still used for module auto loading */
	193	if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL)
	194	continue;
	195	if (minor == SNDRV_MINOR_SEQUENCER \|\|
	196	minor == SNDRV_MINOR_TIMER)
332682b1 CL	197	continue;
	198	if (!snd_minors[minor])
	199	return minor;
	200	}
	201	return -EBUSY;
	202	}
	203	#else
38ebb703	204	static int snd_find_free_minor(int type, struct snd_card *card, int dev)
1da177e4 LT	205	{
	206	int minor;
	207
	208	switch (type) {
	209	case SNDRV_DEVICE_TYPE_SEQUENCER:
	210	case SNDRV_DEVICE_TYPE_TIMER:
	211	minor = type;
	212	break;
	213	case SNDRV_DEVICE_TYPE_CONTROL:
7eaa943c TI	214	if (snd_BUG_ON(!card))
7eaa943c TI	215	return -EINVAL;
1da177e4 LT	216	minor = SNDRV_MINOR(card->number, type);
	217	break;
	218	case SNDRV_DEVICE_TYPE_HWDEP:
	219	case SNDRV_DEVICE_TYPE_RAWMIDI:
	220	case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
	221	case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
3eafc959	222	case SNDRV_DEVICE_TYPE_COMPRESS:
7eaa943c TI	223	if (snd_BUG_ON(!card))
7eaa943c TI	224	return -EINVAL;
1da177e4 LT	225	minor = SNDRV_MINOR(card->number, type + dev);
	226	break;
	227	default:
	228	return -EINVAL;
	229	}
7eaa943c TI	230	if (snd_BUG_ON(minor < 0 \|\| minor >= SNDRV_OS_MINORS))
7eaa943c TI	231	return -EINVAL;
38ebb703 TI	232	if (snd_minors[minor])
38ebb703 TI	233	return -EBUSY;
1da177e4 LT	234	return minor;
1da177e4 LT	235	}
332682b1	236	#endif
1da177e4 LT	237
1da177e4 LT	238	/**
40a4b263	239	* snd_register_device - Register the ALSA device file for the card
1da177e4 LT	240	* @type: the device type, SNDRV_DEVICE_TYPE_XXX
	241	* @card: the card instance
	242	* @dev: the device index
2af677fc	243	* @f_ops: the file operations
f87135f5	244	* @private_data: user pointer for f_ops->open()
40a4b263	245	* @device: the device to register
1da177e4 LT	246	*
	247	* Registers an ALSA device file for the given card.
	248	* The operators have to be set in reg parameter.
	249	*
eb7c06e8	250	* Return: Zero if successful, or a negative error code on failure.
1da177e4	251	*/
40a4b263 TI	252	int snd_register_device(int type, struct snd_card *card, int dev,
	253	const struct file_operations *f_ops,
	254	void private_data, struct device device)
1da177e4	255	{
332682b1	256	int minor;
92b7952d	257	int err = 0;
512bbd6a	258	struct snd_minor *preg;
1da177e4	259
40a4b263 TI	260	if (snd_BUG_ON(!device))
	261	return -EINVAL;
	262
562b590d	263	preg = kmalloc(sizeof *preg, GFP_KERNEL);
1da177e4 LT	264	if (preg == NULL)
1da177e4 LT	265	return -ENOMEM;
2af677fc	266	preg->type = type;
6983b724	267	preg->card = card ? card->number : -1;
1da177e4	268	preg->device = dev;
2af677fc	269	preg->f_ops = f_ops;
f87135f5	270	preg->private_data = private_data;
a0830dbd	271	preg->card_ptr = card;
1a60d4c5	272	mutex_lock(&sound_mutex);
38ebb703	273	minor = snd_find_free_minor(type, card, dev);
332682b1	274	if (minor < 0) {
92b7952d TI	275	err = minor;
92b7952d TI	276	goto error;
1da177e4	277	}
92b7952d	278
40a4b263 TI	279	preg->dev = device;
	280	device->devt = MKDEV(major, minor);
	281	err = device_add(device);
92b7952d TI	282	if (err < 0)
92b7952d TI	283	goto error;
2469049e	284
92b7952d TI	285	snd_minors[minor] = preg;
92b7952d TI	286	error:
1a60d4c5	287	mutex_unlock(&sound_mutex);
92b7952d TI	288	if (err < 0)
	289	kfree(preg);
	290	return err;
1da177e4	291	}
40a4b263	292	EXPORT_SYMBOL(snd_register_device);
c0d3fb39	293
1da177e4 LT	294	/**
1da177e4 LT	295	* snd_unregister_device - unregister the device on the given card
40a4b263	296	* @dev: the device instance
1da177e4 LT	297	*
	298	* Unregisters the device file already registered via
	299	* snd_register_device().
	300	*
eb7c06e8	301	* Return: Zero if successful, or a negative error code on failure.
1da177e4	302	*/
40a4b263	303	int snd_unregister_device(struct device *dev)
1da177e4	304	{
9d19f48c	305	int minor;
92b7952d	306	struct snd_minor *preg;
1da177e4	307
1a60d4c5	308	mutex_lock(&sound_mutex);
40a4b263 TI	309	for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
	310	preg = snd_minors[minor];
	311	if (preg && preg->dev == dev) {
	312	snd_minors[minor] = NULL;
	313	device_del(dev);
	314	kfree(preg);
	315	break;
	316	}
1da177e4	317	}
1a60d4c5	318	mutex_unlock(&sound_mutex);
40a4b263 TI	319	if (minor >= ARRAY_SIZE(snd_minors))
40a4b263 TI	320	return -ENOENT;
1da177e4 LT	321	return 0;
1da177e4 LT	322	}
c0d3fb39 TI	323	EXPORT_SYMBOL(snd_unregister_device);
c0d3fb39 TI	324
cd6a6503	325	#ifdef CONFIG_SND_PROC_FS
1da177e4 LT	326	/*
	327	* INFO PART
	328	*/
2af677fc CL	329	static const char *snd_device_type_name(int type)
	330	{
	331	switch (type) {
	332	case SNDRV_DEVICE_TYPE_CONTROL:
	333	return "control";
	334	case SNDRV_DEVICE_TYPE_HWDEP:
	335	return "hardware dependent";
	336	case SNDRV_DEVICE_TYPE_RAWMIDI:
	337	return "raw midi";
	338	case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
	339	return "digital audio playback";
	340	case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
	341	return "digital audio capture";
	342	case SNDRV_DEVICE_TYPE_SEQUENCER:
	343	return "sequencer";
	344	case SNDRV_DEVICE_TYPE_TIMER:
	345	return "timer";
2c28156d JK	346	case SNDRV_DEVICE_TYPE_COMPRESS:
2c28156d JK	347	return "compress";
2af677fc CL	348	default:
	349	return "?";
	350	}
	351	}
	352
512bbd6a	353	static void snd_minor_info_read(struct snd_info_entry entry, struct snd_info_buffer buffer)
1da177e4	354	{
6983b724	355	int minor;
512bbd6a	356	struct snd_minor *mptr;
1da177e4	357
1a60d4c5	358	mutex_lock(&sound_mutex);
6983b724	359	for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
e3ded899 TI	360	mptr = snd_minors[minor];
e3ded899 TI	361	if (!mptr)
6983b724 CL	362	continue;
	363	if (mptr->card >= 0) {
	364	if (mptr->device >= 0)
d001544d	365	snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
6983b724 CL	366	minor, mptr->card, mptr->device,
	367	snd_device_type_name(mptr->type));
	368	else
d001544d	369	snd_iprintf(buffer, "%3i: [%2i] : %s\n",
6983b724 CL	370	minor, mptr->card,
	371	snd_device_type_name(mptr->type));
	372	} else
d001544d	373	snd_iprintf(buffer, "%3i: : %s\n", minor,
6983b724	374	snd_device_type_name(mptr->type));
1da177e4	375	}
1a60d4c5	376	mutex_unlock(&sound_mutex);
1da177e4 LT	377	}
	378
	379	int __init snd_minor_info_init(void)
	380	{
512bbd6a	381	struct snd_info_entry *entry;
1da177e4 LT	382
1da177e4 LT	383	entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
b591b6e9 TI	384	if (!entry)
	385	return -ENOMEM;
	386	entry->c.text.read = snd_minor_info_read;
	387	return snd_info_register(entry); /* freed in error path */
1da177e4	388	}
cd6a6503	389	#endif /* CONFIG_SND_PROC_FS */
1da177e4 LT	390
	391	/*
	392	* INIT PART
	393	*/
	394
	395	static int __init alsa_sound_init(void)
	396	{
1da177e4 LT	397	snd_major = major;
1da177e4 LT	398	snd_ecards_limit = cards_limit;
1da177e4	399	if (register_chrdev(major, "alsa", &snd_fops)) {
f2f9307a	400	pr_err("ALSA core: unable to register native major device number %d\n", major);
1da177e4 LT	401	return -EIO;
1da177e4 LT	402	}
1da177e4	403	if (snd_info_init() < 0) {
1da177e4	404	unregister_chrdev(major, "alsa");
1da177e4 LT	405	return -ENOMEM;
1da177e4 LT	406	}
2d670ea2 HW	407
	408	#ifdef CONFIG_SND_DEBUG
	409	sound_debugfs_root = debugfs_create_dir("sound", NULL);
	410	#endif
1da177e4	411	#ifndef MODULE
f2f9307a	412	pr_info("Advanced Linux Sound Architecture Driver Initialized.\n");
1da177e4 LT	413	#endif
	414	return 0;
	415	}
	416
	417	static void __exit alsa_sound_exit(void)
	418	{
2d670ea2 HW	419	#ifdef CONFIG_SND_DEBUG
	420	debugfs_remove(sound_debugfs_root);
	421	#endif
1da177e4	422	snd_info_done();
68fc4fab	423	unregister_chrdev(major, "alsa");
1da177e4 LT	424	}
1da177e4 LT	425
c181a13a TLSC	426	subsys_initcall(alsa_sound_init);
c181a13a TLSC	427	module_exit(alsa_sound_exit);