[net-next-2.6.git] / sound / sound_core.c

/*
 *	Sound core handling. Breaks out sound functions to submodules
 *	
 *	Author:		Alan Cox <alan.cox@linux.org>
 *
 *	Fixes:
 *
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 *
 *                         --------------------
 * 
 *	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/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/sound.h>
#include <linux/major.h>
#include <linux/kmod.h>
#include <linux/device.h>

#define SOUND_STEP 16


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

#ifdef CONFIG_SOUND_MSNDCLAS
extern int msnd_classic_init(void);
#endif
#ifdef CONFIG_SOUND_MSNDPIN
extern int msnd_pinnacle_init(void);
#endif

struct class *sound_class;
EXPORT_SYMBOL(sound_class);

/*
 *	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);
	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);

	device_create_drvdata(sound_class, dev,
			      MKDEV(SOUND_MAJOR, s->unit_minor),
			      NULL, s->name+6);
	return r;

 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) {
		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. The allocated number is returned on succes. 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 = 128 + chain;
	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 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, S_IRUSR | S_IWUSR, 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. 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", S_IRUSR | S_IWUSR, NULL);
}

EXPORT_SYMBOL(register_sound_mixer);

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

int register_sound_midi(const struct file_operations *fops, int dev)
{
	return sound_insert_unit(&chains[2], fops, dev, 2, 130,
				 "midi", S_IRUSR | S_IWUSR, NULL);
}

EXPORT_SYMBOL(register_sound_midi);

/*
 *	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. On success the allocated
 *	number is returned, on failure a negative error code is returned.
 *
 *	This function allocates both the audio and dsp device entries together
 *	and will always allocate them as a matching pair - eg dsp3/audio3
 */

int register_sound_dsp(const struct file_operations *fops, int dev)
{
	return sound_insert_unit(&chains[3], fops, dev, 3, 131,
				 "dsp", S_IWUSR | S_IRUSR, 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_midi - unregister a midi device
 *	@unit: unit number to allocate
 *
 *	Release a sound device that was allocated with register_sound_midi().
 *	The unit passed is the return value from the register function.
 */

void unregister_sound_midi(int unit)
{
	return sound_remove_unit(&chains[2], unit);
}

EXPORT_SYMBOL(unregister_sound_midi);

/**
 *	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)
{
	return sound_remove_unit(&chains[3], unit);
}


EXPORT_SYMBOL(unregister_sound_dsp);

/*
 *	Now our file operations
 */

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,
};

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;
}

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;

	lock_kernel ();

	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 (!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);
		spin_lock(&sound_loader_lock);
		s = __look_for_unit(chain, unit);
		if (s)
			new_fops = fops_get(s->unit_fops);
	}
	if (new_fops) {
		/*
		 * We rely upon the fact that we can't be unloaded while the
		 * subdriver is there, so if ->open() is successful we can
		 * safely drop the reference counter and if it is not we can
		 * revert to old ->f_op. Ugly, indeed, but that's the cost of
		 * switching ->f_op in the first place.
		 */
		int err = 0;
		const struct file_operations *old_fops = file->f_op;
		file->f_op = new_fops;
		spin_unlock(&sound_loader_lock);
		if(file->f_op->open)
			err = file->f_op->open(inode,file);
		if (err) {
			fops_put(file->f_op);
			file->f_op = fops_get(old_fops);
		}
		fops_put(old_fops);
		unlock_kernel();
		return err;
	}
	spin_unlock(&sound_loader_lock);
	unlock_kernel();
	return -ENODEV;
}

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

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

static int __init init_soundcore(void)
{
	if (register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops)==-1) {
		printk(KERN_ERR "soundcore: sound device already in use.\n");
		return -EBUSY;
	}
	sound_class = class_create(THIS_MODULE, "sound");
	if (IS_ERR(sound_class))
		return PTR_ERR(sound_class);

	return 0;
}

module_init(init_soundcore);
module_exit(cleanup_soundcore);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Sound core handling. Breaks out sound functions to submodules
	3	*
	4	* Author: Alan Cox <alan.cox@linux.org>
	5	*
	6	* Fixes:
	7	*
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*
	14	* --------------------
	15	*
	16	* Top level handler for the sound subsystem. Various devices can
	17	* plug into this. The fact they don't all go via OSS doesn't mean
	18	* they don't have to implement the OSS API. There is a lot of logic
	19	* to keeping much of the OSS weight out of the code in a compatibility
	20	* module, but it's up to the driver to rember to load it...
	21	*
	22	* The code provides a set of functions for registration of devices
	23	* by type. This is done rather than providing a single call so that
	24	* we can hide any future changes in the internals (eg when we go to
	25	* 32bit dev_t) from the modules and their interface.
	26	*
	27	* Secondly we need to allocate the dsp, dsp16 and audio devices as
	28	* one. Thus we misuse the chains a bit to simplify this.
	29	*
	30	* Thirdly to make it more fun and for 2.3.x and above we do all
	31	* of this using fine grained locking.
	32	*
	33	* FIXME: we have to resolve modules and fine grained load/unload
	34	* locking at some point in 2.3.x.
	35	*/
	36
1da177e4 LT	37	#include <linux/module.h>
	38	#include <linux/init.h>
	39	#include <linux/slab.h>
78a3c3d7	40	#include <linux/smp_lock.h>
1da177e4 LT	41	#include <linux/types.h>
	42	#include <linux/kernel.h>
	43	#include <linux/fs.h>
	44	#include <linux/sound.h>
	45	#include <linux/major.h>
	46	#include <linux/kmod.h>
1da177e4 LT	47	#include <linux/device.h>
	48
	49	#define SOUND_STEP 16
	50
	51
	52	struct sound_unit
	53	{
	54	int unit_minor;
99ac48f5	55	const struct file_operations *unit_fops;
1da177e4 LT	56	struct sound_unit *next;
	57	char name[32];
	58	};
	59
	60	#ifdef CONFIG_SOUND_MSNDCLAS
	61	extern int msnd_classic_init(void);
	62	#endif
	63	#ifdef CONFIG_SOUND_MSNDPIN
	64	extern int msnd_pinnacle_init(void);
	65	#endif
	66
619e666b	67	struct class *sound_class;
1da177e4 LT	68	EXPORT_SYMBOL(sound_class);
	69
	70	/*
	71	* Low level list operator. Scan the ordered list, find a hole and
	72	* join into it. Called with the lock asserted
	73	*/
	74
99ac48f5	75	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	76	{
	77	int n=low;
	78
	79	if (index < 0) { /* first free */
	80
	81	while (list && (list)->unit_minor<n)
	82	list=&((*list)->next);
	83
	84	while(n<top)
	85	{
	86	/* Found a hole ? */
	87	if(list==NULL \|\| (list)->unit_minor>n)
	88	break;
	89	list=&((*list)->next);
	90	n+=SOUND_STEP;
	91	}
	92
	93	if(n>=top)
	94	return -ENOENT;
	95	} else {
	96	n = low+(index*16);
	97	while (*list) {
	98	if ((*list)->unit_minor==n)
	99	return -EBUSY;
	100	if ((*list)->unit_minor>n)
	101	break;
	102	list=&((*list)->next);
	103	}
	104	}
	105
	106	/*
	107	* Fill it in
	108	*/
	109
	110	s->unit_minor=n;
	111	s->unit_fops=fops;
	112
	113	/*
	114	* Link it
	115	*/
	116
	117	s->next=*list;
	118	*list=s;
	119
	120
	121	return n;
	122	}
	123
	124	/*
	125	* Remove a node from the chain. Called with the lock asserted
	126	*/
	127
	128	static struct sound_unit __sound_remove_unit(struct sound_unit *list, int unit)
	129	{
	130	while(*list)
	131	{
	132	struct sound_unit p=list;
	133	if(p->unit_minor==unit)
	134	{
	135	*list=p->next;
	136	return p;
	137	}
	138	list=&(p->next);
	139	}
140	printk(KERN_ERR "Sound device %d went missing!\n", unit);
141	return NULL;
142	}
143
144	/*
145	* This lock guards the sound loader list.
146	*/
147
148	static DEFINE_SPINLOCK(sound_loader_lock);
149
150	/*
151	* Allocate the controlling structure and add it to the sound driver
152	* list. Acquires locks as needed
153	*/
154
99ac48f5	155	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	156	{
	157	struct sound_unit s = kmalloc(sizeof(s), GFP_KERNEL);
	158	int r;
	159
	160	if (!s)
	161	return -ENOMEM;
	162
	163	spin_lock(&sound_loader_lock);
	164	r = __sound_insert_unit(s, list, fops, index, low, top);
	165	spin_unlock(&sound_loader_lock);
	166
	167	if (r < 0)
	168	goto fail;
	169	else if (r < SOUND_STEP)
	170	sprintf(s->name, "sound/%s", name);
	171	else
	172	sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
	173
89409211 GKH	174	device_create_drvdata(sound_class, dev,
	175	MKDEV(SOUND_MAJOR, s->unit_minor),
	176	NULL, s->name+6);
1da177e4 LT	177	return r;
	178
	179	fail:
	180	kfree(s);
	181	return r;
	182	}
	183
	184	/*
	185	* Remove a unit. Acquires locks as needed. The drivers MUST have
	186	* completed the removal before their file operations become
	187	* invalid.
	188	*/
	189
	190	static void sound_remove_unit(struct sound_unit **list, int unit)
	191	{
	192	struct sound_unit *p;
	193
	194	spin_lock(&sound_loader_lock);
	195	p = __sound_remove_unit(list, unit);
	196	spin_unlock(&sound_loader_lock);
	197	if (p) {
d80f19fa	198	device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
1da177e4 LT	199	kfree(p);
	200	}
	201	}
	202
	203	/*
	204	* Allocations
	205	*
	206	* 0 *16 Mixers
	207	* 1 *8 Sequencers
	208	* 2 *16 Midi
	209	* 3 *16 DSP
	210	* 4 *16 SunDSP
	211	* 5 *16 DSP16
	212	* 6 -- sndstat (obsolete)
	213	* 7 *16 unused
	214	* 8 -- alternate sequencer (see above)
	215	* 9 *16 raw synthesizer access
	216	* 10 *16 unused
	217	* 11 *16 unused
	218	* 12 *16 unused
	219	* 13 *16 unused
	220	* 14 *16 unused
	221	* 15 *16 unused
	222	*/
	223
	224	static struct sound_unit *chains[SOUND_STEP];
	225
	226	/**
d568121c	227	* register_sound_special_device - register a special sound node
1da177e4 LT	228	* @fops: File operations for the driver
1da177e4 LT	229	* @unit: Unit number to allocate
d568121c	230	* @dev: device pointer
1da177e4 LT	231	*
	232	* Allocate a special sound device by minor number from the sound
	233	* subsystem. The allocated number is returned on succes. On failure
	234	* a negative error code is returned.
	235	*/
	236
99ac48f5	237	int register_sound_special_device(const struct file_operations *fops, int unit,
d568121c	238	struct device *dev)
1da177e4 LT	239	{
	240	const int chain = unit % SOUND_STEP;
	241	int max_unit = 128 + chain;
	242	const char *name;
	243	char _name[16];
	244
	245	switch (chain) {
	246	case 0:
	247	name = "mixer";
	248	break;
	249	case 1:
	250	name = "sequencer";
	251	if (unit >= SOUND_STEP)
	252	goto __unknown;
	253	max_unit = unit + 1;
	254	break;
	255	case 2:
	256	name = "midi";
	257	break;
	258	case 3:
	259	name = "dsp";
	260	break;
	261	case 4:
	262	name = "audio";
	263	break;
	264	case 8:
	265	name = "sequencer2";
	266	if (unit >= SOUND_STEP)
	267	goto __unknown;
	268	max_unit = unit + 1;
	269	break;
	270	case 9:
	271	name = "dmmidi";
	272	break;
	273	case 10:
	274	name = "dmfm";
	275	break;
	276	case 12:
	277	name = "adsp";
	278	break;
	279	case 13:
	280	name = "amidi";
	281	break;
	282	case 14:
	283	name = "admmidi";
	284	break;
	285	default:
	286	{
	287	__unknown:
	288	sprintf(_name, "unknown%d", chain);
	289	if (unit >= SOUND_STEP)
	290	strcat(_name, "-");
	291	name = _name;
	292	}
	293	break;
	294	}
	295	return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
d568121c	296	name, S_IRUSR \| S_IWUSR, dev);
1da177e4 LT	297	}
1da177e4 LT	298
d568121c TI	299	EXPORT_SYMBOL(register_sound_special_device);
d568121c TI	300
99ac48f5	301	int register_sound_special(const struct file_operations *fops, int unit)
d568121c TI	302	{
	303	return register_sound_special_device(fops, unit, NULL);
	304	}
	305
1da177e4 LT	306	EXPORT_SYMBOL(register_sound_special);
	307
	308	/**
	309	* register_sound_mixer - register a mixer device
	310	* @fops: File operations for the driver
	311	* @dev: Unit number to allocate
	312	*
	313	* Allocate a mixer device. Unit is the number of the mixer requested.
	314	* Pass -1 to request the next free mixer unit. On success the allocated
	315	* number is returned, on failure a negative error code is returned.
	316	*/
	317
99ac48f5	318	int register_sound_mixer(const struct file_operations *fops, int dev)
1da177e4 LT	319	{
1da177e4 LT	320	return sound_insert_unit(&chains[0], fops, dev, 0, 128,
d568121c	321	"mixer", S_IRUSR \| S_IWUSR, NULL);
1da177e4 LT	322	}
	323
	324	EXPORT_SYMBOL(register_sound_mixer);
	325
	326	/**
	327	* register_sound_midi - register a midi device
	328	* @fops: File operations for the driver
	329	* @dev: Unit number to allocate
	330	*
	331	* Allocate a midi device. Unit is the number of the midi device requested.
	332	* Pass -1 to request the next free midi unit. On success the allocated
	333	* number is returned, on failure a negative error code is returned.
	334	*/
	335
99ac48f5	336	int register_sound_midi(const struct file_operations *fops, int dev)
1da177e4 LT	337	{
1da177e4 LT	338	return sound_insert_unit(&chains[2], fops, dev, 2, 130,
d568121c	339	"midi", S_IRUSR \| S_IWUSR, NULL);
1da177e4 LT	340	}
	341
	342	EXPORT_SYMBOL(register_sound_midi);
	343
	344	/*
	345	* DSP's are registered as a triple. Register only one and cheat
	346	* in open - see below.
	347	*/
	348
	349	/**
	350	* register_sound_dsp - register a DSP device
	351	* @fops: File operations for the driver
	352	* @dev: Unit number to allocate
	353	*
	354	* Allocate a DSP device. Unit is the number of the DSP requested.
	355	* Pass -1 to request the next free DSP unit. On success the allocated
	356	* number is returned, on failure a negative error code is returned.
	357	*
	358	* This function allocates both the audio and dsp device entries together
	359	* and will always allocate them as a matching pair - eg dsp3/audio3
	360	*/
	361
99ac48f5	362	int register_sound_dsp(const struct file_operations *fops, int dev)
1da177e4 LT	363	{
1da177e4 LT	364	return sound_insert_unit(&chains[3], fops, dev, 3, 131,
d568121c	365	"dsp", S_IWUSR \| S_IRUSR, NULL);
1da177e4 LT	366	}
	367
	368	EXPORT_SYMBOL(register_sound_dsp);
	369
1da177e4 LT	370	/**
	371	* unregister_sound_special - unregister a special sound device
	372	* @unit: unit number to allocate
	373	*
	374	* Release a sound device that was allocated with
	375	* register_sound_special(). The unit passed is the return value from
	376	* the register function.
	377	*/
	378
	379
	380	void unregister_sound_special(int unit)
	381	{
	382	sound_remove_unit(&chains[unit % SOUND_STEP], unit);
	383	}
	384
	385	EXPORT_SYMBOL(unregister_sound_special);
	386
	387	/**
	388	* unregister_sound_mixer - unregister a mixer
	389	* @unit: unit number to allocate
	390	*
	391	* Release a sound device that was allocated with register_sound_mixer().
	392	* The unit passed is the return value from the register function.
	393	*/
	394
	395	void unregister_sound_mixer(int unit)
	396	{
	397	sound_remove_unit(&chains[0], unit);
	398	}
	399
	400	EXPORT_SYMBOL(unregister_sound_mixer);
	401
	402	/**
	403	* unregister_sound_midi - unregister a midi device
	404	* @unit: unit number to allocate
	405	*
	406	* Release a sound device that was allocated with register_sound_midi().
	407	* The unit passed is the return value from the register function.
	408	*/
	409
	410	void unregister_sound_midi(int unit)
	411	{
	412	return sound_remove_unit(&chains[2], unit);
	413	}
	414
	415	EXPORT_SYMBOL(unregister_sound_midi);
	416
	417	/**
	418	* unregister_sound_dsp - unregister a DSP device
	419	* @unit: unit number to allocate
	420	*
	421	* Release a sound device that was allocated with register_sound_dsp().
	422	* The unit passed is the return value from the register function.
	423	*
	424	* Both of the allocated units are released together automatically.
	425	*/
	426
	427	void unregister_sound_dsp(int unit)
	428	{
	429	return sound_remove_unit(&chains[3], unit);
	430	}
	431
	432
	433	EXPORT_SYMBOL(unregister_sound_dsp);
434
1da177e4 LT	435	/*
	436	* Now our file operations
	437	*/
	438
	439	static int soundcore_open(struct inode , struct file );
	440
9c2e08c5	441	static const struct file_operations soundcore_fops=
1da177e4 LT	442	{
	443	/* We must have an owner or the module locking fails */
	444	.owner = THIS_MODULE,
	445	.open = soundcore_open,
	446	};
	447
	448	static struct sound_unit *__look_for_unit(int chain, int unit)
	449	{
	450	struct sound_unit *s;
	451
	452	s=chains[chain];
	453	while(s && s->unit_minor <= unit)
	454	{
	455	if(s->unit_minor==unit)
	456	return s;
	457	s=s->next;
	458	}
	459	return NULL;
	460	}
	461
	462	int soundcore_open(struct inode inode, struct file file)
	463	{
	464	int chain;
	465	int unit = iminor(inode);
	466	struct sound_unit *s;
99ac48f5	467	const struct file_operations *new_fops = NULL;
1da177e4	468
78a3c3d7 JC	469	lock_kernel ();
78a3c3d7 JC	470
1da177e4 LT	471	chain=unit&0x0F;
	472	if(chain==4 \|\| chain==5) /* dsp/audio/dsp16 */
	473	{
	474	unit&=0xF0;
	475	unit\|=3;
	476	chain=3;
	477	}
	478
	479	spin_lock(&sound_loader_lock);
	480	s = __look_for_unit(chain, unit);
	481	if (s)
	482	new_fops = fops_get(s->unit_fops);
	483	if (!new_fops) {
	484	spin_unlock(&sound_loader_lock);
	485	/*
	486	* Please, don't change this order or code.
	487	* For ALSA slot means soundcard and OSS emulation code
	488	* comes as add-on modules which aren't depend on
	489	* ALSA toplevel modules for soundcards, thus we need
	490	* load them at first. [Jaroslav Kysela <perex@jcu.cz>]
	491	*/
	492	request_module("sound-slot-%i", unit>>4);
	493	request_module("sound-service-%i-%i", unit>>4, chain);
	494	spin_lock(&sound_loader_lock);
	495	s = __look_for_unit(chain, unit);
	496	if (s)
	497	new_fops = fops_get(s->unit_fops);
	498	}
	499	if (new_fops) {
	500	/*
	501	* We rely upon the fact that we can't be unloaded while the
	502	* subdriver is there, so if ->open() is successful we can
	503	* safely drop the reference counter and if it is not we can
	504	* revert to old ->f_op. Ugly, indeed, but that's the cost of
	505	* switching ->f_op in the first place.
	506	*/
	507	int err = 0;
99ac48f5	508	const struct file_operations *old_fops = file->f_op;
1da177e4 LT	509	file->f_op = new_fops;
	510	spin_unlock(&sound_loader_lock);
	511	if(file->f_op->open)
	512	err = file->f_op->open(inode,file);
	513	if (err) {
	514	fops_put(file->f_op);
	515	file->f_op = fops_get(old_fops);
	516	}
	517	fops_put(old_fops);
78a3c3d7	518	unlock_kernel();
1da177e4 LT	519	return err;
	520	}
	521	spin_unlock(&sound_loader_lock);
78a3c3d7	522	unlock_kernel();
1da177e4 LT	523	return -ENODEV;
	524	}
	525
1da177e4 LT	526	MODULE_DESCRIPTION("Core sound module");
	527	MODULE_AUTHOR("Alan Cox");
	528	MODULE_LICENSE("GPL");
	529	MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
	530
	531	static void __exit cleanup_soundcore(void)
	532	{
	533	/* We have nothing to really do here - we know the lists must be
	534	empty */
	535	unregister_chrdev(SOUND_MAJOR, "sound");
619e666b	536	class_destroy(sound_class);
1da177e4 LT	537	}
	538
	539	static int __init init_soundcore(void)
	540	{
	541	if (register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops)==-1) {
	542	printk(KERN_ERR "soundcore: sound device already in use.\n");
	543	return -EBUSY;
	544	}
619e666b	545	sound_class = class_create(THIS_MODULE, "sound");
1da177e4 LT	546	if (IS_ERR(sound_class))
	547	return PTR_ERR(sound_class);
	548
	549	return 0;
	550	}
	551
	552	module_init(init_soundcore);
	553	module_exit(cleanup_soundcore);