[linux.git] / sound / sound_core.c

/*
 *	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(struct device *dev, mode_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(THIS_MODULE, "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 <[email protected]>
 *
 *	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/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];
};

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

/*
 * 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.  Please take a look at
 * feature-removal-schedule.txt for details.
 */
#ifdef CONFIG_SOUND_OSS_CORE_PRECLAIM
static int preclaim_oss = 1;
#else
static int preclaim_oss = 0;
#endif

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);
			return -EBUSY;
		}
	}

	device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
		      NULL, 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. 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 = 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 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, 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)
{
	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)
{
	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 <[email protected]>]
		 */
		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);
	}
	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);
		return err;
	}
	spin_unlock(&sound_loader_lock);
	return -ENODEV;
}

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) == -1) {
		printk(KERN_ERR "soundcore: sound device already in use.\n");
		return -EBUSY;
	}

	return 0;
}

#endif /* CONFIG_SOUND_OSS_CORE */
Commit	Line	Data
1da177e4	1	/*
d886e87c TH	2	* Sound core. This file is composed of two parts. sound_class
	3	* which is common to both OSS and ALSA and OSS sound core which
	4	* is used OSS or emulation of it.
	5	*/
	6
	7	/*
	8	* First, the common part.
	9	*/
	10	#include <linux/module.h>
	11	#include <linux/device.h>
	12	#include <linux/err.h>
954a973c KS	13	#include <linux/kdev_t.h>
954a973c KS	14	#include <linux/major.h>
3d1ee379	15	#include <sound/core.h>
d886e87c TH	16
	17	#ifdef CONFIG_SOUND_OSS_CORE
	18	static int __init init_oss_soundcore(void);
de30d36b	19	static void cleanup_oss_soundcore(void);
d886e87c TH	20	#else
	21	static inline int init_oss_soundcore(void) { return 0; }
	22	static inline void cleanup_oss_soundcore(void) { }
	23	#endif
	24
	25	struct class *sound_class;
	26	EXPORT_SYMBOL(sound_class);
	27
	28	MODULE_DESCRIPTION("Core sound module");
	29	MODULE_AUTHOR("Alan Cox");
	30	MODULE_LICENSE("GPL");
	31
e454cea2	32	static char sound_devnode(struct device dev, mode_t *mode)
7a9d56f6	33	{
954a973c KS	34	if (MAJOR(dev->devt) == SOUND_MAJOR)
954a973c KS	35	return NULL;
7a9d56f6 KS	36	return kasprintf(GFP_KERNEL, "snd/%s", dev_name(dev));
	37	}
	38
d886e87c TH	39	static int __init init_soundcore(void)
	40	{
	41	int rc;
	42
	43	rc = init_oss_soundcore();
	44	if (rc)
	45	return rc;
	46
	47	sound_class = class_create(THIS_MODULE, "sound");
	48	if (IS_ERR(sound_class)) {
	49	cleanup_oss_soundcore();
	50	return PTR_ERR(sound_class);
	51	}
	52
e454cea2	53	sound_class->devnode = sound_devnode;
7a9d56f6	54
d886e87c TH	55	return 0;
	56	}
	57
	58	static void __exit cleanup_soundcore(void)
	59	{
	60	cleanup_oss_soundcore();
	61	class_destroy(sound_class);
	62	}
	63
c181a13a	64	subsys_initcall(init_soundcore);
d886e87c TH	65	module_exit(cleanup_soundcore);
	66
	67
	68	#ifdef CONFIG_SOUND_OSS_CORE
	69	/*
	70	* OSS sound core handling. Breaks out sound functions to submodules
1da177e4	71	*
2f1e593d	72	* Author: Alan Cox <[email protected]>
1da177e4 LT	73	*
	74	* Fixes:
	75	*
	76	*
	77	* This program is free software; you can redistribute it and/or
	78	* modify it under the terms of the GNU General Public License
	79	* as published by the Free Software Foundation; either version
	80	* 2 of the License, or (at your option) any later version.
	81	*
	82	* --------------------
	83	*
	84	* Top level handler for the sound subsystem. Various devices can
	85	* plug into this. The fact they don't all go via OSS doesn't mean
	86	* they don't have to implement the OSS API. There is a lot of logic
	87	* to keeping much of the OSS weight out of the code in a compatibility
	88	* module, but it's up to the driver to rember to load it...
	89	*
	90	* The code provides a set of functions for registration of devices
	91	* by type. This is done rather than providing a single call so that
	92	* we can hide any future changes in the internals (eg when we go to
	93	* 32bit dev_t) from the modules and their interface.
	94	*
	95	* Secondly we need to allocate the dsp, dsp16 and audio devices as
	96	* one. Thus we misuse the chains a bit to simplify this.
	97	*
	98	* Thirdly to make it more fun and for 2.3.x and above we do all
	99	* of this using fine grained locking.
	100	*
	101	* FIXME: we have to resolve modules and fine grained load/unload
	102	* locking at some point in 2.3.x.
	103	*/
	104
1da177e4 LT	105	#include <linux/init.h>
	106	#include <linux/slab.h>
	107	#include <linux/types.h>
	108	#include <linux/kernel.h>
1da177e4	109	#include <linux/sound.h>
1da177e4	110	#include <linux/kmod.h>
1da177e4 LT	111
	112	#define SOUND_STEP 16
	113
1da177e4 LT	114	struct sound_unit
	115	{
	116	int unit_minor;
99ac48f5	117	const struct file_operations *unit_fops;
1da177e4 LT	118	struct sound_unit *next;
	119	char name[32];
	120	};
	121
	122	#ifdef CONFIG_SOUND_MSNDCLAS
	123	extern int msnd_classic_init(void);
	124	#endif
	125	#ifdef CONFIG_SOUND_MSNDPIN
	126	extern int msnd_pinnacle_init(void);
	127	#endif
	128
93fe4483 TH	129	/*
	130	* By default, OSS sound_core claims full legacy minor range (0-255)
	131	* of SOUND_MAJOR to trap open attempts to any sound minor and
	132	* requests modules using custom sound-slot/service-* module aliases.
	133	* The only benefit of doing this is allowing use of custom module
	134	* aliases instead of the standard char-major-* ones. This behavior
	135	* prevents alternative OSS implementation and is scheduled to be
	136	* removed.
	137	*
	138	* CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss kernel
	139	* parameter are added to allow distros and developers to try and
	140	* switch to alternative implementations without needing to rebuild
	141	* the kernel in the meantime. If preclaim_oss is non-zero, the
	142	* kernel will behave the same as before. All SOUND_MAJOR minors are
	143	* preclaimed and the custom module aliases along with standard chrdev
	144	* ones are emitted if a missing device is opened. If preclaim_oss is
	145	* zero, sound_core only grabs what's actually in use and for missing
	146	* devices only the standard chrdev aliases are requested.
	147	*
	148	* All these clutters are scheduled to be removed along with
	149	* sound-slot/service-* module aliases. Please take a look at
	150	* feature-removal-schedule.txt for details.
	151	*/
	152	#ifdef CONFIG_SOUND_OSS_CORE_PRECLAIM
	153	static int preclaim_oss = 1;
	154	#else
	155	static int preclaim_oss = 0;
	156	#endif
	157
	158	module_param(preclaim_oss, int, 0444);
	159
	160	static int soundcore_open(struct inode , struct file );
	161
	162	static const struct file_operations soundcore_fops =
	163	{
	164	/* We must have an owner or the module locking fails */
	165	.owner = THIS_MODULE,
	166	.open = soundcore_open,
6038f373	167	.llseek = noop_llseek,
93fe4483 TH	168	};
93fe4483 TH	169
1da177e4 LT	170	/*
	171	* Low level list operator. Scan the ordered list, find a hole and
	172	* join into it. Called with the lock asserted
	173	*/
	174
99ac48f5	175	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	176	{
	177	int n=low;
	178
	179	if (index < 0) { /* first free */
	180
	181	while (list && (list)->unit_minor<n)
	182	list=&((*list)->next);
	183
	184	while(n<top)
	185	{
	186	/* Found a hole ? */
	187	if(list==NULL \|\| (list)->unit_minor>n)
	188	break;
	189	list=&((*list)->next);
	190	n+=SOUND_STEP;
	191	}
	192
	193	if(n>=top)
	194	return -ENOENT;
	195	} else {
	196	n = low+(index*16);
	197	while (*list) {
	198	if ((*list)->unit_minor==n)
	199	return -EBUSY;
	200	if ((*list)->unit_minor>n)
	201	break;
	202	list=&((*list)->next);
	203	}
	204	}
	205
	206	/*
	207	* Fill it in
	208	*/
	209
	210	s->unit_minor=n;
	211	s->unit_fops=fops;
	212
	213	/*
	214	* Link it
	215	*/
	216
	217	s->next=*list;
	218	*list=s;
	219
	220
	221	return n;
	222	}
	223
	224	/*
	225	* Remove a node from the chain. Called with the lock asserted
	226	*/
	227
	228	static struct sound_unit __sound_remove_unit(struct sound_unit *list, int unit)
	229	{
	230	while(*list)
	231	{
	232	struct sound_unit p=list;
	233	if(p->unit_minor==unit)
	234	{
	235	*list=p->next;
	236	return p;
	237	}
	238	list=&(p->next);
	239	}
240	printk(KERN_ERR "Sound device %d went missing!\n", unit);
241	return NULL;
242	}
243
244	/*
245	* This lock guards the sound loader list.
246	*/
247
248	static DEFINE_SPINLOCK(sound_loader_lock);
249
250	/*
251	* Allocate the controlling structure and add it to the sound driver
252	* list. Acquires locks as needed
253	*/
254
99ac48f5	255	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	256	{
	257	struct sound_unit s = kmalloc(sizeof(s), GFP_KERNEL);
	258	int r;
	259
	260	if (!s)
	261	return -ENOMEM;
93fe4483	262
1da177e4	263	spin_lock(&sound_loader_lock);
93fe4483	264	retry:
1da177e4 LT	265	r = __sound_insert_unit(s, list, fops, index, low, top);
	266	spin_unlock(&sound_loader_lock);
	267
	268	if (r < 0)
	269	goto fail;
	270	else if (r < SOUND_STEP)
	271	sprintf(s->name, "sound/%s", name);
	272	else
	273	sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
	274
93fe4483 TH	275	if (!preclaim_oss) {
	276	/*
	277	* Something else might have grabbed the minor. If
	278	* first free slot is requested, rescan with @low set
	279	* to the next unit; otherwise, -EBUSY.
	280	*/
	281	r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name,
	282	&soundcore_fops);
	283	if (r < 0) {
	284	spin_lock(&sound_loader_lock);
	285	__sound_remove_unit(list, s->unit_minor);
	286	if (index < 0) {
	287	low = s->unit_minor + SOUND_STEP;
	288	goto retry;
	289	}
	290	spin_unlock(&sound_loader_lock);
	291	return -EBUSY;
	292	}
	293	}
	294
abe9ab8f GKH	295	device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
abe9ab8f GKH	296	NULL, s->name+6);
93fe4483	297	return s->unit_minor;
1da177e4	298
93fe4483	299	fail:
1da177e4 LT	300	kfree(s);
	301	return r;
	302	}
	303
	304	/*
	305	* Remove a unit. Acquires locks as needed. The drivers MUST have
	306	* completed the removal before their file operations become
	307	* invalid.
	308	*/
	309
	310	static void sound_remove_unit(struct sound_unit **list, int unit)
	311	{
	312	struct sound_unit *p;
	313
	314	spin_lock(&sound_loader_lock);
	315	p = __sound_remove_unit(list, unit);
	316	spin_unlock(&sound_loader_lock);
	317	if (p) {
93fe4483 TH	318	if (!preclaim_oss)
	319	__unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
	320	p->name);
d80f19fa	321	device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
1da177e4 LT	322	kfree(p);
	323	}
	324	}
	325
	326	/*
	327	* Allocations
	328	*
	329	* 0 *16 Mixers
	330	* 1 *8 Sequencers
	331	* 2 *16 Midi
	332	* 3 *16 DSP
	333	* 4 *16 SunDSP
	334	* 5 *16 DSP16
	335	* 6 -- sndstat (obsolete)
	336	* 7 *16 unused
	337	* 8 -- alternate sequencer (see above)
	338	* 9 *16 raw synthesizer access
	339	* 10 *16 unused
	340	* 11 *16 unused
	341	* 12 *16 unused
	342	* 13 *16 unused
	343	* 14 *16 unused
	344	* 15 *16 unused
	345	*/
	346
	347	static struct sound_unit *chains[SOUND_STEP];
	348
	349	/**
d568121c	350	* register_sound_special_device - register a special sound node
1da177e4 LT	351	* @fops: File operations for the driver
1da177e4 LT	352	* @unit: Unit number to allocate
d568121c	353	* @dev: device pointer
1da177e4 LT	354	*
1da177e4 LT	355	* Allocate a special sound device by minor number from the sound
af901ca1	356	* subsystem. The allocated number is returned on success. On failure
1da177e4 LT	357	* a negative error code is returned.
	358	*/
	359
99ac48f5	360	int register_sound_special_device(const struct file_operations *fops, int unit,
d568121c	361	struct device *dev)
1da177e4 LT	362	{
	363	const int chain = unit % SOUND_STEP;
	364	int max_unit = 128 + chain;
	365	const char *name;
	366	char _name[16];
	367
	368	switch (chain) {
	369	case 0:
	370	name = "mixer";
	371	break;
	372	case 1:
	373	name = "sequencer";
	374	if (unit >= SOUND_STEP)
	375	goto __unknown;
	376	max_unit = unit + 1;
	377	break;
	378	case 2:
	379	name = "midi";
	380	break;
	381	case 3:
	382	name = "dsp";
	383	break;
	384	case 4:
	385	name = "audio";
	386	break;
848669da TI	387	case 5:
	388	name = "dspW";
	389	break;
1da177e4 LT	390	case 8:
	391	name = "sequencer2";
	392	if (unit >= SOUND_STEP)
	393	goto __unknown;
	394	max_unit = unit + 1;
	395	break;
	396	case 9:
	397	name = "dmmidi";
	398	break;
	399	case 10:
	400	name = "dmfm";
	401	break;
	402	case 12:
	403	name = "adsp";
	404	break;
	405	case 13:
	406	name = "amidi";
	407	break;
	408	case 14:
	409	name = "admmidi";
	410	break;
	411	default:
	412	{
	413	__unknown:
	414	sprintf(_name, "unknown%d", chain);
	415	if (unit >= SOUND_STEP)
	416	strcat(_name, "-");
	417	name = _name;
	418	}
	419	break;
	420	}
	421	return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
d568121c	422	name, S_IRUSR \| S_IWUSR, dev);
1da177e4 LT	423	}
1da177e4 LT	424
d568121c TI	425	EXPORT_SYMBOL(register_sound_special_device);
d568121c TI	426
99ac48f5	427	int register_sound_special(const struct file_operations *fops, int unit)
d568121c TI	428	{
	429	return register_sound_special_device(fops, unit, NULL);
	430	}
	431
1da177e4 LT	432	EXPORT_SYMBOL(register_sound_special);
	433
	434	/**
	435	* register_sound_mixer - register a mixer device
	436	* @fops: File operations for the driver
	437	* @dev: Unit number to allocate
	438	*
	439	* Allocate a mixer device. Unit is the number of the mixer requested.
	440	* Pass -1 to request the next free mixer unit. On success the allocated
	441	* number is returned, on failure a negative error code is returned.
	442	*/
	443
99ac48f5	444	int register_sound_mixer(const struct file_operations *fops, int dev)
1da177e4 LT	445	{
1da177e4 LT	446	return sound_insert_unit(&chains[0], fops, dev, 0, 128,
d568121c	447	"mixer", S_IRUSR \| S_IWUSR, NULL);
1da177e4 LT	448	}
	449
	450	EXPORT_SYMBOL(register_sound_mixer);
	451
	452	/**
	453	* register_sound_midi - register a midi device
	454	* @fops: File operations for the driver
	455	* @dev: Unit number to allocate
	456	*
	457	* Allocate a midi device. Unit is the number of the midi device requested.
	458	* Pass -1 to request the next free midi unit. On success the allocated
	459	* number is returned, on failure a negative error code is returned.
	460	*/
	461
99ac48f5	462	int register_sound_midi(const struct file_operations *fops, int dev)
1da177e4 LT	463	{
1da177e4 LT	464	return sound_insert_unit(&chains[2], fops, dev, 2, 130,
d568121c	465	"midi", S_IRUSR \| S_IWUSR, NULL);
1da177e4 LT	466	}
	467
	468	EXPORT_SYMBOL(register_sound_midi);
	469
	470	/*
	471	* DSP's are registered as a triple. Register only one and cheat
	472	* in open - see below.
	473	*/
	474
	475	/**
	476	* register_sound_dsp - register a DSP device
	477	* @fops: File operations for the driver
	478	* @dev: Unit number to allocate
	479	*
	480	* Allocate a DSP device. Unit is the number of the DSP requested.
	481	* Pass -1 to request the next free DSP unit. On success the allocated
	482	* number is returned, on failure a negative error code is returned.
	483	*
	484	* This function allocates both the audio and dsp device entries together
	485	* and will always allocate them as a matching pair - eg dsp3/audio3
	486	*/
	487
99ac48f5	488	int register_sound_dsp(const struct file_operations *fops, int dev)
1da177e4 LT	489	{
1da177e4 LT	490	return sound_insert_unit(&chains[3], fops, dev, 3, 131,
d568121c	491	"dsp", S_IWUSR \| S_IRUSR, NULL);
1da177e4 LT	492	}
	493
	494	EXPORT_SYMBOL(register_sound_dsp);
	495
1da177e4 LT	496	/**
	497	* unregister_sound_special - unregister a special sound device
	498	* @unit: unit number to allocate
	499	*
	500	* Release a sound device that was allocated with
	501	* register_sound_special(). The unit passed is the return value from
	502	* the register function.
	503	*/
	504
	505
	506	void unregister_sound_special(int unit)
	507	{
	508	sound_remove_unit(&chains[unit % SOUND_STEP], unit);
	509	}
	510
	511	EXPORT_SYMBOL(unregister_sound_special);
	512
	513	/**
	514	* unregister_sound_mixer - unregister a mixer
	515	* @unit: unit number to allocate
	516	*
	517	* Release a sound device that was allocated with register_sound_mixer().
	518	* The unit passed is the return value from the register function.
	519	*/
	520
	521	void unregister_sound_mixer(int unit)
	522	{
	523	sound_remove_unit(&chains[0], unit);
	524	}
	525
	526	EXPORT_SYMBOL(unregister_sound_mixer);
	527
	528	/**
	529	* unregister_sound_midi - unregister a midi device
	530	* @unit: unit number to allocate
	531	*
	532	* Release a sound device that was allocated with register_sound_midi().
	533	* The unit passed is the return value from the register function.
	534	*/
	535
	536	void unregister_sound_midi(int unit)
	537	{
a39c4ad1	538	sound_remove_unit(&chains[2], unit);
1da177e4 LT	539	}
	540
	541	EXPORT_SYMBOL(unregister_sound_midi);
	542
	543	/**
	544	* unregister_sound_dsp - unregister a DSP device
	545	* @unit: unit number to allocate
	546	*
	547	* Release a sound device that was allocated with register_sound_dsp().
	548	* The unit passed is the return value from the register function.
	549	*
	550	* Both of the allocated units are released together automatically.
	551	*/
	552
	553	void unregister_sound_dsp(int unit)
	554	{
a39c4ad1	555	sound_remove_unit(&chains[3], unit);
1da177e4 LT	556	}
	557
	558
	559	EXPORT_SYMBOL(unregister_sound_dsp);
	560
1da177e4 LT	561	static struct sound_unit *__look_for_unit(int chain, int unit)
	562	{
	563	struct sound_unit *s;
	564
	565	s=chains[chain];
	566	while(s && s->unit_minor <= unit)
	567	{
	568	if(s->unit_minor==unit)
	569	return s;
	570	s=s->next;
	571	}
	572	return NULL;
	573	}
	574
a39c4ad1	575	static int soundcore_open(struct inode inode, struct file file)
1da177e4 LT	576	{
	577	int chain;
	578	int unit = iminor(inode);
	579	struct sound_unit *s;
99ac48f5	580	const struct file_operations *new_fops = NULL;
1da177e4 LT	581
	582	chain=unit&0x0F;
	583	if(chain==4 \|\| chain==5) /* dsp/audio/dsp16 */
	584	{
	585	unit&=0xF0;
	586	unit\|=3;
	587	chain=3;
	588	}
	589
	590	spin_lock(&sound_loader_lock);
	591	s = __look_for_unit(chain, unit);
	592	if (s)
	593	new_fops = fops_get(s->unit_fops);
93fe4483	594	if (preclaim_oss && !new_fops) {
1da177e4	595	spin_unlock(&sound_loader_lock);
0a848680	596
1da177e4 LT	597	/*
	598	* Please, don't change this order or code.
	599	* For ALSA slot means soundcard and OSS emulation code
	600	* comes as add-on modules which aren't depend on
	601	* ALSA toplevel modules for soundcards, thus we need
	602	* load them at first. [Jaroslav Kysela <[email protected]>]
	603	*/
	604	request_module("sound-slot-%i", unit>>4);
	605	request_module("sound-service-%i-%i", unit>>4, chain);
0a848680 TH	606
	607	/*
	608	* sound-slot/service-* module aliases are scheduled
	609	* for removal in favor of the standard char-major-*
	610	* module aliases. For the time being, generate both
	611	* the legacy and standard module aliases to ease
	612	* transition.
	613	*/
	614	if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
	615	request_module("char-major-%d", SOUND_MAJOR);
	616
1da177e4 LT	617	spin_lock(&sound_loader_lock);
	618	s = __look_for_unit(chain, unit);
	619	if (s)
	620	new_fops = fops_get(s->unit_fops);
	621	}
	622	if (new_fops) {
	623	/*
	624	* We rely upon the fact that we can't be unloaded while the
	625	* subdriver is there, so if ->open() is successful we can
	626	* safely drop the reference counter and if it is not we can
	627	* revert to old ->f_op. Ugly, indeed, but that's the cost of
	628	* switching ->f_op in the first place.
	629	*/
	630	int err = 0;
99ac48f5	631	const struct file_operations *old_fops = file->f_op;
1da177e4 LT	632	file->f_op = new_fops;
1da177e4 LT	633	spin_unlock(&sound_loader_lock);
171d9f7d	634
90dc763f	635	if (file->f_op->open)
1da177e4	636	err = file->f_op->open(inode,file);
171d9f7d	637
1da177e4 LT	638	if (err) {
	639	fops_put(file->f_op);
	640	file->f_op = fops_get(old_fops);
	641	}
171d9f7d	642
1da177e4 LT	643	fops_put(old_fops);
	644	return err;
	645	}
	646	spin_unlock(&sound_loader_lock);
	647	return -ENODEV;
	648	}
	649
1da177e4 LT	650	MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
1da177e4 LT	651
de30d36b	652	static void cleanup_oss_soundcore(void)
1da177e4 LT	653	{
	654	/* We have nothing to really do here - we know the lists must be
	655	empty */
	656	unregister_chrdev(SOUND_MAJOR, "sound");
1da177e4 LT	657	}
1da177e4 LT	658
d886e87c	659	static int __init init_oss_soundcore(void)
1da177e4	660	{
93fe4483 TH	661	if (preclaim_oss &&
93fe4483 TH	662	register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) == -1) {
1da177e4 LT	663	printk(KERN_ERR "soundcore: sound device already in use.\n");
	664	return -EBUSY;
	665	}
1da177e4 LT	666
	667	return 0;
	668	}
	669
d886e87c	670	#endif /* CONFIG_SOUND_OSS_CORE */