[linux-block.git] / sound / sound_core.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	Sound core.  This file is composed of two parts.  sound_class
 *	which is common to both OSS and ALSA and OSS sound core which
 *	is used OSS or emulation of it.
 */

/*
 * First, the common part.
 */
#include <linux/module.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/kdev_t.h>
#include <linux/major.h>
#include <sound/core.h>

#ifdef CONFIG_SOUND_OSS_CORE
static int __init init_oss_soundcore(void);
static void cleanup_oss_soundcore(void);
#else
static inline int init_oss_soundcore(void)	{ return 0; }
static inline void cleanup_oss_soundcore(void)	{ }
#endif

struct class *sound_class;
EXPORT_SYMBOL(sound_class);

MODULE_DESCRIPTION("Core sound module");
MODULE_AUTHOR("Alan Cox");
MODULE_LICENSE("GPL");

static char *sound_devnode(const struct device *dev, umode_t *mode)
{
	if (MAJOR(dev->devt) == SOUND_MAJOR)
		return NULL;
	return kasprintf(GFP_KERNEL, "snd/%s", dev_name(dev));
}

static int __init init_soundcore(void)
{
	int rc;

	rc = init_oss_soundcore();
	if (rc)
		return rc;

	sound_class = class_create("sound");
	if (IS_ERR(sound_class)) {
		cleanup_oss_soundcore();
		return PTR_ERR(sound_class);
	}

	sound_class->devnode = sound_devnode;

	return 0;
}

static void __exit cleanup_soundcore(void)
{
	cleanup_oss_soundcore();
	class_destroy(sound_class);
}

subsys_initcall(init_soundcore);
module_exit(cleanup_soundcore);


#ifdef CONFIG_SOUND_OSS_CORE
/*
 *	OSS sound core handling. Breaks out sound functions to submodules
 *	
 *	Author:		Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 *	Fixes:
 *
 *                         --------------------
 * 
 *	Top level handler for the sound subsystem. Various devices can
 *	plug into this. The fact they don't all go via OSS doesn't mean 
 *	they don't have to implement the OSS API. There is a lot of logic
 *	to keeping much of the OSS weight out of the code in a compatibility
 *	module, but it's up to the driver to rember to load it...
 *
 *	The code provides a set of functions for registration of devices
 *	by type. This is done rather than providing a single call so that
 *	we can hide any future changes in the internals (eg when we go to
 *	32bit dev_t) from the modules and their interface.
 *
 *	Secondly we need to allocate the dsp, dsp16 and audio devices as
 *	one. Thus we misuse the chains a bit to simplify this.
 *
 *	Thirdly to make it more fun and for 2.3.x and above we do all
 *	of this using fine grained locking.
 *
 *	FIXME: we have to resolve modules and fine grained load/unload
 *	locking at some point in 2.3.x.
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sound.h>
#include <linux/kmod.h>

#define SOUND_STEP 16

struct sound_unit
{
	int unit_minor;
	const struct file_operations *unit_fops;
	struct sound_unit *next;
	char name[32];
};

/*
 * By default, OSS sound_core claims full legacy minor range (0-255)
 * of SOUND_MAJOR to trap open attempts to any sound minor and
 * requests modules using custom sound-slot/service-* module aliases.
 * The only benefit of doing this is allowing use of custom module
 * aliases instead of the standard char-major-* ones.  This behavior
 * prevents alternative OSS implementation and is scheduled to be
 * removed.
 *
 * CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss kernel
 * parameter are added to allow distros and developers to try and
 * switch to alternative implementations without needing to rebuild
 * the kernel in the meantime.  If preclaim_oss is non-zero, the
 * kernel will behave the same as before.  All SOUND_MAJOR minors are
 * preclaimed and the custom module aliases along with standard chrdev
 * ones are emitted if a missing device is opened.  If preclaim_oss is
 * zero, sound_core only grabs what's actually in use and for missing
 * devices only the standard chrdev aliases are requested.
 *
 * All these clutters are scheduled to be removed along with
 * sound-slot/service-* module aliases.
 */
static int preclaim_oss = IS_ENABLED(CONFIG_SOUND_OSS_CORE_PRECLAIM);

module_param(preclaim_oss, int, 0444);

static int soundcore_open(struct inode *, struct file *);

static const struct file_operations soundcore_fops =
{
	/* We must have an owner or the module locking fails */
	.owner	= THIS_MODULE,
	.open	= soundcore_open,
	.llseek = noop_llseek,
};

/*
 *	Low level list operator. Scan the ordered list, find a hole and
 *	join into it. Called with the lock asserted
 */

static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, const struct file_operations *fops, int index, int low, int top)
{
	int n=low;

	if (index < 0) {	/* first free */

		while (*list && (*list)->unit_minor<n)
			list=&((*list)->next);

		while(n<top)
		{
			/* Found a hole ? */
			if(*list==NULL || (*list)->unit_minor>n)
				break;
			list=&((*list)->next);
			n+=SOUND_STEP;
		}

		if(n>=top)
			return -ENOENT;
	} else {
		n = low+(index*16);
		while (*list) {
			if ((*list)->unit_minor==n)
				return -EBUSY;
			if ((*list)->unit_minor>n)
				break;
			list=&((*list)->next);
		}
	}	
		
	/*
	 *	Fill it in
	 */
	 
	s->unit_minor=n;
	s->unit_fops=fops;
	
	/*
	 *	Link it
	 */
	 
	s->next=*list;
	*list=s;
	
	
	return n;
}

/*
 *	Remove a node from the chain. Called with the lock asserted
 */
 
static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit)
{
	while(*list)
	{
		struct sound_unit *p=*list;
		if(p->unit_minor==unit)
		{
			*list=p->next;
			return p;
		}
		list=&(p->next);
	}
	printk(KERN_ERR "Sound device %d went missing!\n", unit);
	return NULL;
}

/*
 *	This lock guards the sound loader list.
 */

static DEFINE_SPINLOCK(sound_loader_lock);

/*
 *	Allocate the controlling structure and add it to the sound driver
 *	list. Acquires locks as needed
 */

static int sound_insert_unit(struct sound_unit **list, const struct file_operations *fops, int index, int low, int top, const char *name, umode_t mode, struct device *dev)
{
	struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL);
	int r;

	if (!s)
		return -ENOMEM;

	spin_lock(&sound_loader_lock);
retry:
	r = __sound_insert_unit(s, list, fops, index, low, top);
	spin_unlock(&sound_loader_lock);
	
	if (r < 0)
		goto fail;
	else if (r < SOUND_STEP)
		sprintf(s->name, "sound/%s", name);
	else
		sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);

	if (!preclaim_oss) {
		/*
		 * Something else might have grabbed the minor.  If
		 * first free slot is requested, rescan with @low set
		 * to the next unit; otherwise, -EBUSY.
		 */
		r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name,
				      &soundcore_fops);
		if (r < 0) {
			spin_lock(&sound_loader_lock);
			__sound_remove_unit(list, s->unit_minor);
			if (index < 0) {
				low = s->unit_minor + SOUND_STEP;
				goto retry;
			}
			spin_unlock(&sound_loader_lock);
			r = -EBUSY;
			goto fail;
		}
	}

	device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
		      NULL, "%s", s->name+6);
	return s->unit_minor;

fail:
	kfree(s);
	return r;
}

/*
 *	Remove a unit. Acquires locks as needed. The drivers MUST have
 *	completed the removal before their file operations become
 *	invalid.
 */
 	
static void sound_remove_unit(struct sound_unit **list, int unit)
{
	struct sound_unit *p;

	spin_lock(&sound_loader_lock);
	p = __sound_remove_unit(list, unit);
	spin_unlock(&sound_loader_lock);
	if (p) {
		if (!preclaim_oss)
			__unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
					    p->name);
		device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
		kfree(p);
	}
}

/*
 *	Allocations
 *
 *	0	*16		Mixers
 *	1	*8		Sequencers
 *	2	*16		Midi
 *	3	*16		DSP
 *	4	*16		SunDSP
 *	5	*16		DSP16
 *	6	--		sndstat (obsolete)
 *	7	*16		unused
 *	8	--		alternate sequencer (see above)
 *	9	*16		raw synthesizer access
 *	10	*16		unused
 *	11	*16		unused
 *	12	*16		unused
 *	13	*16		unused
 *	14	*16		unused
 *	15	*16		unused
 */

static struct sound_unit *chains[SOUND_STEP];

/**
 *	register_sound_special_device - register a special sound node
 *	@fops: File operations for the driver
 *	@unit: Unit number to allocate
 *      @dev: device pointer
 *
 *	Allocate a special sound device by minor number from the sound
 *	subsystem.
 *
 *	Return: The allocated number is returned on success. On failure,
 *	a negative error code is returned.
 */
 
int register_sound_special_device(const struct file_operations *fops, int unit,
				  struct device *dev)
{
	const int chain = unit % SOUND_STEP;
	int max_unit = 256;
	const char *name;
	char _name[16];

	switch (chain) {
	    case 0:
		name = "mixer";
		break;
	    case 1:
		name = "sequencer";
		if (unit >= SOUND_STEP)
			goto __unknown;
		max_unit = unit + 1;
		break;
	    case 2:
		name = "midi";
		break;
	    case 3:
		name = "dsp";
		break;
	    case 4:
		name = "audio";
		break;
	    case 5:
		name = "dspW";
		break;
	    case 8:
		name = "sequencer2";
		if (unit >= SOUND_STEP)
			goto __unknown;
		max_unit = unit + 1;
		break;
	    case 9:
		name = "dmmidi";
		break;
	    case 10:
		name = "dmfm";
		break;
	    case 12:
		name = "adsp";
		break;
	    case 13:
		name = "amidi";
		break;
	    case 14:
		name = "admmidi";
		break;
	    default:
	    	{
		    __unknown:
			sprintf(_name, "unknown%d", chain);
		    	if (unit >= SOUND_STEP)
		    		strcat(_name, "-");
		    	name = _name;
		}
		break;
	}
	return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
				 name, 0600, dev);
}
 
EXPORT_SYMBOL(register_sound_special_device);

int register_sound_special(const struct file_operations *fops, int unit)
{
	return register_sound_special_device(fops, unit, NULL);
}

EXPORT_SYMBOL(register_sound_special);

/**
 *	register_sound_mixer - register a mixer device
 *	@fops: File operations for the driver
 *	@dev: Unit number to allocate
 *
 *	Allocate a mixer device. Unit is the number of the mixer requested.
 *	Pass -1 to request the next free mixer unit.
 *
 *	Return: On success, the allocated number is returned. On failure,
 *	a negative error code is returned.
 */

int register_sound_mixer(const struct file_operations *fops, int dev)
{
	return sound_insert_unit(&chains[0], fops, dev, 0, 128,
				 "mixer", 0600, NULL);
}

EXPORT_SYMBOL(register_sound_mixer);

/*
 *	DSP's are registered as a triple. Register only one and cheat
 *	in open - see below.
 */
 
/**
 *	register_sound_dsp - register a DSP device
 *	@fops: File operations for the driver
 *	@dev: Unit number to allocate
 *
 *	Allocate a DSP device. Unit is the number of the DSP requested.
 *	Pass -1 to request the next free DSP unit.
 *
 *	This function allocates both the audio and dsp device entries together
 *	and will always allocate them as a matching pair - eg dsp3/audio3
 *
 *	Return: On success, the allocated number is returned. On failure,
 *	a negative error code is returned.
 */

int register_sound_dsp(const struct file_operations *fops, int dev)
{
	return sound_insert_unit(&chains[3], fops, dev, 3, 131,
				 "dsp", 0600, NULL);
}

EXPORT_SYMBOL(register_sound_dsp);

/**
 *	unregister_sound_special - unregister a special sound device
 *	@unit: unit number to allocate
 *
 *	Release a sound device that was allocated with
 *	register_sound_special(). The unit passed is the return value from
 *	the register function.
 */


void unregister_sound_special(int unit)
{
	sound_remove_unit(&chains[unit % SOUND_STEP], unit);
}
 
EXPORT_SYMBOL(unregister_sound_special);

/**
 *	unregister_sound_mixer - unregister a mixer
 *	@unit: unit number to allocate
 *
 *	Release a sound device that was allocated with register_sound_mixer().
 *	The unit passed is the return value from the register function.
 */

void unregister_sound_mixer(int unit)
{
	sound_remove_unit(&chains[0], unit);
}

EXPORT_SYMBOL(unregister_sound_mixer);

/**
 *	unregister_sound_dsp - unregister a DSP device
 *	@unit: unit number to allocate
 *
 *	Release a sound device that was allocated with register_sound_dsp().
 *	The unit passed is the return value from the register function.
 *
 *	Both of the allocated units are released together automatically.
 */

void unregister_sound_dsp(int unit)
{
	sound_remove_unit(&chains[3], unit);
}


EXPORT_SYMBOL(unregister_sound_dsp);

static struct sound_unit *__look_for_unit(int chain, int unit)
{
	struct sound_unit *s;
	
	s=chains[chain];
	while(s && s->unit_minor <= unit)
	{
		if(s->unit_minor==unit)
			return s;
		s=s->next;
	}
	return NULL;
}

static int soundcore_open(struct inode *inode, struct file *file)
{
	int chain;
	int unit = iminor(inode);
	struct sound_unit *s;
	const struct file_operations *new_fops = NULL;

	chain=unit&0x0F;
	if(chain==4 || chain==5)	/* dsp/audio/dsp16 */
	{
		unit&=0xF0;
		unit|=3;
		chain=3;
	}
	
	spin_lock(&sound_loader_lock);
	s = __look_for_unit(chain, unit);
	if (s)
		new_fops = fops_get(s->unit_fops);
	if (preclaim_oss && !new_fops) {
		spin_unlock(&sound_loader_lock);

		/*
		 *  Please, don't change this order or code.
		 *  For ALSA slot means soundcard and OSS emulation code
		 *  comes as add-on modules which aren't depend on
		 *  ALSA toplevel modules for soundcards, thus we need
		 *  load them at first.	  [Jaroslav Kysela <perex@jcu.cz>]
		 */
		request_module("sound-slot-%i", unit>>4);
		request_module("sound-service-%i-%i", unit>>4, chain);

		/*
		 * sound-slot/service-* module aliases are scheduled
		 * for removal in favor of the standard char-major-*
		 * module aliases.  For the time being, generate both
		 * the legacy and standard module aliases to ease
		 * transition.
		 */
		if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
			request_module("char-major-%d", SOUND_MAJOR);

		spin_lock(&sound_loader_lock);
		s = __look_for_unit(chain, unit);
		if (s)
			new_fops = fops_get(s->unit_fops);
	}
	spin_unlock(&sound_loader_lock);

	if (!new_fops)
		return -ENODEV;

	/*
	 * We rely upon the fact that we can't be unloaded while the
	 * subdriver is there.
	 */
	replace_fops(file, new_fops);

	if (!file->f_op->open)
		return -ENODEV;

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

MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);

static void cleanup_oss_soundcore(void)
{
	/* We have nothing to really do here - we know the lists must be
	   empty */
	unregister_chrdev(SOUND_MAJOR, "sound");
}

static int __init init_oss_soundcore(void)
{
	if (preclaim_oss &&
	    register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) < 0) {
		printk(KERN_ERR "soundcore: sound device already in use.\n");
		return -EBUSY;
	}

	return 0;
}

#endif /* CONFIG_SOUND_OSS_CORE */
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4	2	/*
d886e87c TH	3	* Sound core. This file is composed of two parts. sound_class
	4	* which is common to both OSS and ALSA and OSS sound core which
	5	* is used OSS or emulation of it.
	6	*/
	7
	8	/*
	9	* First, the common part.
	10	*/
	11	#include <linux/module.h>
	12	#include <linux/device.h>
	13	#include <linux/err.h>
954a973c KS	14	#include <linux/kdev_t.h>
954a973c KS	15	#include <linux/major.h>
3d1ee379	16	#include <sound/core.h>
d886e87c TH	17
	18	#ifdef CONFIG_SOUND_OSS_CORE
	19	static int __init init_oss_soundcore(void);
de30d36b	20	static void cleanup_oss_soundcore(void);
d886e87c TH	21	#else
	22	static inline int init_oss_soundcore(void) { return 0; }
	23	static inline void cleanup_oss_soundcore(void) { }
	24	#endif
	25
	26	struct class *sound_class;
	27	EXPORT_SYMBOL(sound_class);
	28
	29	MODULE_DESCRIPTION("Core sound module");
	30	MODULE_AUTHOR("Alan Cox");
	31	MODULE_LICENSE("GPL");
	32
ff62b8e6	33	static char sound_devnode(const struct device dev, umode_t *mode)
7a9d56f6	34	{
954a973c KS	35	if (MAJOR(dev->devt) == SOUND_MAJOR)
954a973c KS	36	return NULL;
7a9d56f6 KS	37	return kasprintf(GFP_KERNEL, "snd/%s", dev_name(dev));
	38	}
	39
d886e87c TH	40	static int __init init_soundcore(void)
	41	{
	42	int rc;
	43
	44	rc = init_oss_soundcore();
	45	if (rc)
	46	return rc;
	47
1aaba11d	48	sound_class = class_create("sound");
d886e87c TH	49	if (IS_ERR(sound_class)) {
	50	cleanup_oss_soundcore();
	51	return PTR_ERR(sound_class);
	52	}
	53
e454cea2	54	sound_class->devnode = sound_devnode;
7a9d56f6	55
d886e87c TH	56	return 0;
	57	}
	58
	59	static void __exit cleanup_soundcore(void)
	60	{
	61	cleanup_oss_soundcore();
	62	class_destroy(sound_class);
	63	}
	64
c181a13a	65	subsys_initcall(init_soundcore);
d886e87c TH	66	module_exit(cleanup_soundcore);
	67
	68
	69	#ifdef CONFIG_SOUND_OSS_CORE
	70	/*
	71	* OSS sound core handling. Breaks out sound functions to submodules
1da177e4	72	*
2f1e593d	73	* Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
1da177e4 LT	74	*
	75	* Fixes:
	76	*
1da177e4 LT	77	* --------------------
	78	*
	79	* Top level handler for the sound subsystem. Various devices can
	80	* plug into this. The fact they don't all go via OSS doesn't mean
	81	* they don't have to implement the OSS API. There is a lot of logic
	82	* to keeping much of the OSS weight out of the code in a compatibility
	83	* module, but it's up to the driver to rember to load it...
	84	*
	85	* The code provides a set of functions for registration of devices
	86	* by type. This is done rather than providing a single call so that
	87	* we can hide any future changes in the internals (eg when we go to
	88	* 32bit dev_t) from the modules and their interface.
	89	*
	90	* Secondly we need to allocate the dsp, dsp16 and audio devices as
	91	* one. Thus we misuse the chains a bit to simplify this.
	92	*
	93	* Thirdly to make it more fun and for 2.3.x and above we do all
	94	* of this using fine grained locking.
	95	*
	96	* FIXME: we have to resolve modules and fine grained load/unload
	97	* locking at some point in 2.3.x.
	98	*/
	99
1da177e4 LT	100	#include <linux/init.h>
	101	#include <linux/slab.h>
	102	#include <linux/types.h>
	103	#include <linux/kernel.h>
1da177e4	104	#include <linux/sound.h>
1da177e4	105	#include <linux/kmod.h>
1da177e4 LT	106
	107	#define SOUND_STEP 16
	108
1da177e4 LT	109	struct sound_unit
	110	{
	111	int unit_minor;
99ac48f5	112	const struct file_operations *unit_fops;
1da177e4 LT	113	struct sound_unit *next;
	114	char name[32];
	115	};
	116
93fe4483 TH	117	/*
	118	* By default, OSS sound_core claims full legacy minor range (0-255)
	119	* of SOUND_MAJOR to trap open attempts to any sound minor and
	120	* requests modules using custom sound-slot/service-* module aliases.
	121	* The only benefit of doing this is allowing use of custom module
	122	* aliases instead of the standard char-major-* ones. This behavior
	123	* prevents alternative OSS implementation and is scheduled to be
	124	* removed.
	125	*
	126	* CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss kernel
	127	* parameter are added to allow distros and developers to try and
	128	* switch to alternative implementations without needing to rebuild
	129	* the kernel in the meantime. If preclaim_oss is non-zero, the
	130	* kernel will behave the same as before. All SOUND_MAJOR minors are
	131	* preclaimed and the custom module aliases along with standard chrdev
	132	* ones are emitted if a missing device is opened. If preclaim_oss is
	133	* zero, sound_core only grabs what's actually in use and for missing
	134	* devices only the standard chrdev aliases are requested.
	135	*
	136	* All these clutters are scheduled to be removed along with
8f6e6041	137	* sound-slot/service-* module aliases.
93fe4483	138	*/
d248b277	139	static int preclaim_oss = IS_ENABLED(CONFIG_SOUND_OSS_CORE_PRECLAIM);
93fe4483 TH	140
	141	module_param(preclaim_oss, int, 0444);
	142
	143	static int soundcore_open(struct inode , struct file );
	144
	145	static const struct file_operations soundcore_fops =
	146	{
	147	/* We must have an owner or the module locking fails */
	148	.owner = THIS_MODULE,
	149	.open = soundcore_open,
6038f373	150	.llseek = noop_llseek,
93fe4483 TH	151	};
93fe4483 TH	152
1da177e4 LT	153	/*
	154	* Low level list operator. Scan the ordered list, find a hole and
	155	* join into it. Called with the lock asserted
	156	*/
	157
99ac48f5	158	static int __sound_insert_unit(struct sound_unit * s, struct sound_unit *list, const struct file_operations fops, int index, int low, int top)
1da177e4 LT	159	{
	160	int n=low;
	161
	162	if (index < 0) { /* first free */
	163
	164	while (list && (list)->unit_minor<n)
	165	list=&((*list)->next);
	166
	167	while(n<top)
	168	{
	169	/* Found a hole ? */
	170	if(list==NULL \|\| (list)->unit_minor>n)
	171	break;
	172	list=&((*list)->next);
	173	n+=SOUND_STEP;
	174	}
	175
	176	if(n>=top)
	177	return -ENOENT;
	178	} else {
	179	n = low+(index*16);
	180	while (*list) {
	181	if ((*list)->unit_minor==n)
	182	return -EBUSY;
	183	if ((*list)->unit_minor>n)
	184	break;
	185	list=&((*list)->next);
	186	}
	187	}
	188
	189	/*
	190	* Fill it in
	191	*/
	192
	193	s->unit_minor=n;
	194	s->unit_fops=fops;
	195
	196	/*
	197	* Link it
	198	*/
	199
	200	s->next=*list;
	201	*list=s;
	202
	203
	204	return n;
	205	}
	206
	207	/*
	208	* Remove a node from the chain. Called with the lock asserted
	209	*/
	210
	211	static struct sound_unit __sound_remove_unit(struct sound_unit *list, int unit)
	212	{
	213	while(*list)
	214	{
	215	struct sound_unit p=list;
	216	if(p->unit_minor==unit)
	217	{
	218	*list=p->next;
	219	return p;
	220	}
	221	list=&(p->next);
	222	}
223	printk(KERN_ERR "Sound device %d went missing!\n", unit);
224	return NULL;
225	}
226
227	/*
228	* This lock guards the sound loader list.
229	*/
230
231	static DEFINE_SPINLOCK(sound_loader_lock);
232
233	/*
234	* Allocate the controlling structure and add it to the sound driver
235	* list. Acquires locks as needed
236	*/
237
99ac48f5	238	static int sound_insert_unit(struct sound_unit *list, const struct file_operations fops, int index, int low, int top, const char name, umode_t mode, struct device dev)
1da177e4 LT	239	{
	240	struct sound_unit s = kmalloc(sizeof(s), GFP_KERNEL);
	241	int r;
	242
	243	if (!s)
	244	return -ENOMEM;
93fe4483	245
1da177e4	246	spin_lock(&sound_loader_lock);
93fe4483	247	retry:
1da177e4 LT	248	r = __sound_insert_unit(s, list, fops, index, low, top);
	249	spin_unlock(&sound_loader_lock);
	250
	251	if (r < 0)
	252	goto fail;
	253	else if (r < SOUND_STEP)
	254	sprintf(s->name, "sound/%s", name);
	255	else
	256	sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
	257
93fe4483 TH	258	if (!preclaim_oss) {
	259	/*
	260	* Something else might have grabbed the minor. If
	261	* first free slot is requested, rescan with @low set
	262	* to the next unit; otherwise, -EBUSY.
	263	*/
	264	r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name,
	265	&soundcore_fops);
	266	if (r < 0) {
	267	spin_lock(&sound_loader_lock);
	268	__sound_remove_unit(list, s->unit_minor);
	269	if (index < 0) {
	270	low = s->unit_minor + SOUND_STEP;
	271	goto retry;
	272	}
	273	spin_unlock(&sound_loader_lock);
c7cd7c74 WW	274	r = -EBUSY;
c7cd7c74 WW	275	goto fail;
93fe4483 TH	276	}
	277	}
	278
abe9ab8f	279	device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
02aa2a37	280	NULL, "%s", s->name+6);
93fe4483	281	return s->unit_minor;
1da177e4	282
93fe4483	283	fail:
1da177e4 LT	284	kfree(s);
	285	return r;
	286	}
	287
	288	/*
	289	* Remove a unit. Acquires locks as needed. The drivers MUST have
	290	* completed the removal before their file operations become
	291	* invalid.
	292	*/
	293
	294	static void sound_remove_unit(struct sound_unit **list, int unit)
	295	{
	296	struct sound_unit *p;
	297
	298	spin_lock(&sound_loader_lock);
	299	p = __sound_remove_unit(list, unit);
	300	spin_unlock(&sound_loader_lock);
	301	if (p) {
93fe4483 TH	302	if (!preclaim_oss)
	303	__unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
	304	p->name);
d80f19fa	305	device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
1da177e4 LT	306	kfree(p);
	307	}
	308	}
	309
	310	/*
	311	* Allocations
	312	*
	313	* 0 *16 Mixers
	314	* 1 *8 Sequencers
	315	* 2 *16 Midi
	316	* 3 *16 DSP
	317	* 4 *16 SunDSP
	318	* 5 *16 DSP16
	319	* 6 -- sndstat (obsolete)
	320	* 7 *16 unused
	321	* 8 -- alternate sequencer (see above)
	322	* 9 *16 raw synthesizer access
	323	* 10 *16 unused
	324	* 11 *16 unused
	325	* 12 *16 unused
	326	* 13 *16 unused
	327	* 14 *16 unused
	328	* 15 *16 unused
	329	*/
	330
	331	static struct sound_unit *chains[SOUND_STEP];
	332
	333	/**
d568121c	334	* register_sound_special_device - register a special sound node
1da177e4 LT	335	* @fops: File operations for the driver
1da177e4 LT	336	* @unit: Unit number to allocate
d568121c	337	* @dev: device pointer
1da177e4 LT	338	*
1da177e4 LT	339	* Allocate a special sound device by minor number from the sound
eb7c06e8 YB	340	* subsystem.
	341	*
	342	* Return: The allocated number is returned on success. On failure,
1da177e4 LT	343	* a negative error code is returned.
	344	*/
	345
99ac48f5	346	int register_sound_special_device(const struct file_operations *fops, int unit,
d568121c	347	struct device *dev)
1da177e4 LT	348	{
1da177e4 LT	349	const int chain = unit % SOUND_STEP;
2abb8017	350	int max_unit = 256;
1da177e4 LT	351	const char *name;
	352	char _name[16];
	353
	354	switch (chain) {
	355	case 0:
	356	name = "mixer";
	357	break;
	358	case 1:
	359	name = "sequencer";
	360	if (unit >= SOUND_STEP)
	361	goto __unknown;
	362	max_unit = unit + 1;
	363	break;
	364	case 2:
	365	name = "midi";
	366	break;
	367	case 3:
	368	name = "dsp";
	369	break;
	370	case 4:
	371	name = "audio";
	372	break;
848669da TI	373	case 5:
	374	name = "dspW";
	375	break;
1da177e4 LT	376	case 8:
	377	name = "sequencer2";
	378	if (unit >= SOUND_STEP)
	379	goto __unknown;
	380	max_unit = unit + 1;
	381	break;
	382	case 9:
	383	name = "dmmidi";
	384	break;
	385	case 10:
	386	name = "dmfm";
	387	break;
	388	case 12:
	389	name = "adsp";
	390	break;
	391	case 13:
	392	name = "amidi";
	393	break;
	394	case 14:
	395	name = "admmidi";
	396	break;
	397	default:
	398	{
	399	__unknown:
	400	sprintf(_name, "unknown%d", chain);
	401	if (unit >= SOUND_STEP)
	402	strcat(_name, "-");
	403	name = _name;
	404	}
	405	break;
	406	}
	407	return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
6a73cf46	408	name, 0600, dev);
1da177e4 LT	409	}
1da177e4 LT	410
d568121c TI	411	EXPORT_SYMBOL(register_sound_special_device);
d568121c TI	412
99ac48f5	413	int register_sound_special(const struct file_operations *fops, int unit)
d568121c TI	414	{
	415	return register_sound_special_device(fops, unit, NULL);
	416	}
	417
1da177e4 LT	418	EXPORT_SYMBOL(register_sound_special);
	419
	420	/**
	421	* register_sound_mixer - register a mixer device
	422	* @fops: File operations for the driver
	423	* @dev: Unit number to allocate
	424	*
	425	* Allocate a mixer device. Unit is the number of the mixer requested.
eb7c06e8 YB	426	* Pass -1 to request the next free mixer unit.
	427	*
	428	* Return: On success, the allocated number is returned. On failure,
	429	* a negative error code is returned.
1da177e4 LT	430	*/
1da177e4 LT	431
99ac48f5	432	int register_sound_mixer(const struct file_operations *fops, int dev)
1da177e4 LT	433	{
1da177e4 LT	434	return sound_insert_unit(&chains[0], fops, dev, 0, 128,
6a73cf46	435	"mixer", 0600, NULL);
1da177e4 LT	436	}
	437
	438	EXPORT_SYMBOL(register_sound_mixer);
	439
1da177e4 LT	440	/*
	441	* DSP's are registered as a triple. Register only one and cheat
	442	* in open - see below.
	443	*/
	444
	445	/**
	446	* register_sound_dsp - register a DSP device
	447	* @fops: File operations for the driver
	448	* @dev: Unit number to allocate
	449	*
	450	* Allocate a DSP device. Unit is the number of the DSP requested.
eb7c06e8	451	* Pass -1 to request the next free DSP unit.
1da177e4 LT	452	*
	453	* This function allocates both the audio and dsp device entries together
	454	* and will always allocate them as a matching pair - eg dsp3/audio3
eb7c06e8 YB	455	*
	456	* Return: On success, the allocated number is returned. On failure,
	457	* a negative error code is returned.
1da177e4 LT	458	*/
1da177e4 LT	459
99ac48f5	460	int register_sound_dsp(const struct file_operations *fops, int dev)
1da177e4 LT	461	{
1da177e4 LT	462	return sound_insert_unit(&chains[3], fops, dev, 3, 131,
6a73cf46	463	"dsp", 0600, NULL);
1da177e4 LT	464	}
	465
	466	EXPORT_SYMBOL(register_sound_dsp);
	467
1da177e4 LT	468	/**
	469	* unregister_sound_special - unregister a special sound device
	470	* @unit: unit number to allocate
	471	*
	472	* Release a sound device that was allocated with
	473	* register_sound_special(). The unit passed is the return value from
	474	* the register function.
	475	*/
	476
	477
	478	void unregister_sound_special(int unit)
	479	{
	480	sound_remove_unit(&chains[unit % SOUND_STEP], unit);
	481	}
	482
	483	EXPORT_SYMBOL(unregister_sound_special);
	484
	485	/**
	486	* unregister_sound_mixer - unregister a mixer
	487	* @unit: unit number to allocate
	488	*
	489	* Release a sound device that was allocated with register_sound_mixer().
	490	* The unit passed is the return value from the register function.
	491	*/
	492
	493	void unregister_sound_mixer(int unit)
	494	{
	495	sound_remove_unit(&chains[0], unit);
	496	}
	497
	498	EXPORT_SYMBOL(unregister_sound_mixer);
	499
1da177e4 LT	500	/**
	501	* unregister_sound_dsp - unregister a DSP device
	502	* @unit: unit number to allocate
	503	*
	504	* Release a sound device that was allocated with register_sound_dsp().
	505	* The unit passed is the return value from the register function.
	506	*
	507	* Both of the allocated units are released together automatically.
	508	*/
	509
	510	void unregister_sound_dsp(int unit)
	511	{
a39c4ad1	512	sound_remove_unit(&chains[3], unit);
1da177e4 LT	513	}
	514
	515
	516	EXPORT_SYMBOL(unregister_sound_dsp);
	517
1da177e4 LT	518	static struct sound_unit *__look_for_unit(int chain, int unit)
	519	{
	520	struct sound_unit *s;
	521
	522	s=chains[chain];
	523	while(s && s->unit_minor <= unit)
	524	{
	525	if(s->unit_minor==unit)
	526	return s;
	527	s=s->next;
	528	}
	529	return NULL;
	530	}
	531
a39c4ad1	532	static int soundcore_open(struct inode inode, struct file file)
1da177e4 LT	533	{
	534	int chain;
	535	int unit = iminor(inode);
	536	struct sound_unit *s;
99ac48f5	537	const struct file_operations *new_fops = NULL;
1da177e4 LT	538
	539	chain=unit&0x0F;
	540	if(chain==4 \|\| chain==5) /* dsp/audio/dsp16 */
	541	{
	542	unit&=0xF0;
	543	unit\|=3;
	544	chain=3;
	545	}
	546
	547	spin_lock(&sound_loader_lock);
	548	s = __look_for_unit(chain, unit);
	549	if (s)
	550	new_fops = fops_get(s->unit_fops);
93fe4483	551	if (preclaim_oss && !new_fops) {
1da177e4	552	spin_unlock(&sound_loader_lock);
0a848680	553
1da177e4 LT	554	/*
	555	* Please, don't change this order or code.
	556	* For ALSA slot means soundcard and OSS emulation code
	557	* comes as add-on modules which aren't depend on
	558	* ALSA toplevel modules for soundcards, thus we need
	559	* load them at first. [Jaroslav Kysela <perex@jcu.cz>]
	560	*/
	561	request_module("sound-slot-%i", unit>>4);
	562	request_module("sound-service-%i-%i", unit>>4, chain);
0a848680 TH	563
	564	/*
	565	* sound-slot/service-* module aliases are scheduled
	566	* for removal in favor of the standard char-major-*
	567	* module aliases. For the time being, generate both
	568	* the legacy and standard module aliases to ease
	569	* transition.
	570	*/
	571	if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
	572	request_module("char-major-%d", SOUND_MAJOR);
	573
1da177e4 LT	574	spin_lock(&sound_loader_lock);
	575	s = __look_for_unit(chain, unit);
	576	if (s)
	577	new_fops = fops_get(s->unit_fops);
	578	}
e84f9e57	579	spin_unlock(&sound_loader_lock);
171d9f7d	580
e52b78f8 MT	581	if (!new_fops)
e52b78f8 MT	582	return -ENODEV;
171d9f7d	583
e52b78f8 MT	584	/*
	585	* We rely upon the fact that we can't be unloaded while the
	586	* subdriver is there.
	587	*/
	588	replace_fops(file, new_fops);
	589
	590	if (!file->f_op->open)
	591	return -ENODEV;
	592
	593	return file->f_op->open(inode, file);
1da177e4 LT	594	}
1da177e4 LT	595
1da177e4 LT	596	MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
1da177e4 LT	597
de30d36b	598	static void cleanup_oss_soundcore(void)
1da177e4 LT	599	{
	600	/* We have nothing to really do here - we know the lists must be
	601	empty */
	602	unregister_chrdev(SOUND_MAJOR, "sound");
1da177e4 LT	603	}
1da177e4 LT	604
d886e87c	605	static int __init init_oss_soundcore(void)
1da177e4	606	{
93fe4483	607	if (preclaim_oss &&
cb68429d	608	register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) < 0) {
1da177e4 LT	609	printk(KERN_ERR "soundcore: sound device already in use.\n");
	610	return -EBUSY;
	611	}
1da177e4 LT	612
	613	return 0;
	614	}
	615
d886e87c	616	#endif /* CONFIG_SOUND_OSS_CORE */