[GitHub/mt8127/android_kernel_alcatel_ttab.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, 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(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 <alan@lxorguk.ukuu.org.uk>
 *
 *	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.
 */
#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.
 *
 *	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, 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.
 *
 *	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", 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.
 *
 *	Return: 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.
 *
 *	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", 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 <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);
	}
	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
2c9ede55	32	static char sound_devnode(struct device dev, umode_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 <alan@lxorguk.ukuu.org.uk>
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
8f6e6041	149	* sound-slot/service-* module aliases.
93fe4483 TH	150	*/
	151	#ifdef CONFIG_SOUND_OSS_CORE_PRECLAIM
	152	static int preclaim_oss = 1;
	153	#else
	154	static int preclaim_oss = 0;
	155	#endif
	156
	157	module_param(preclaim_oss, int, 0444);
	158
	159	static int soundcore_open(struct inode , struct file );
	160
	161	static const struct file_operations soundcore_fops =
	162	{
	163	/* We must have an owner or the module locking fails */
	164	.owner = THIS_MODULE,
	165	.open = soundcore_open,
6038f373	166	.llseek = noop_llseek,
93fe4483 TH	167	};
93fe4483 TH	168
1da177e4 LT	169	/*
	170	* Low level list operator. Scan the ordered list, find a hole and
	171	* join into it. Called with the lock asserted
	172	*/
	173
99ac48f5	174	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	175	{
	176	int n=low;
	177
	178	if (index < 0) { /* first free */
	179
	180	while (list && (list)->unit_minor<n)
	181	list=&((*list)->next);
	182
	183	while(n<top)
	184	{
	185	/* Found a hole ? */
	186	if(list==NULL \|\| (list)->unit_minor>n)
	187	break;
	188	list=&((*list)->next);
	189	n+=SOUND_STEP;
	190	}
	191
	192	if(n>=top)
	193	return -ENOENT;
	194	} else {
	195	n = low+(index*16);
	196	while (*list) {
	197	if ((*list)->unit_minor==n)
	198	return -EBUSY;
	199	if ((*list)->unit_minor>n)
	200	break;
	201	list=&((*list)->next);
	202	}
	203	}
	204
	205	/*
	206	* Fill it in
	207	*/
	208
	209	s->unit_minor=n;
	210	s->unit_fops=fops;
	211
	212	/*
	213	* Link it
	214	*/
	215
	216	s->next=*list;
	217	*list=s;
	218
	219
	220	return n;
	221	}
	222
	223	/*
	224	* Remove a node from the chain. Called with the lock asserted
	225	*/
	226
	227	static struct sound_unit __sound_remove_unit(struct sound_unit *list, int unit)
	228	{
	229	while(*list)
	230	{
	231	struct sound_unit p=list;
	232	if(p->unit_minor==unit)
	233	{
	234	*list=p->next;
	235	return p;
	236	}
	237	list=&(p->next);
	238	}
239	printk(KERN_ERR "Sound device %d went missing!\n", unit);
240	return NULL;
241	}
242
243	/*
244	* This lock guards the sound loader list.
245	*/
246
247	static DEFINE_SPINLOCK(sound_loader_lock);
248
249	/*
250	* Allocate the controlling structure and add it to the sound driver
251	* list. Acquires locks as needed
252	*/
253
99ac48f5	254	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	255	{
	256	struct sound_unit s = kmalloc(sizeof(s), GFP_KERNEL);
	257	int r;
	258
	259	if (!s)
	260	return -ENOMEM;
93fe4483	261
1da177e4	262	spin_lock(&sound_loader_lock);
93fe4483	263	retry:
1da177e4 LT	264	r = __sound_insert_unit(s, list, fops, index, low, top);
	265	spin_unlock(&sound_loader_lock);
	266
	267	if (r < 0)
	268	goto fail;
	269	else if (r < SOUND_STEP)
	270	sprintf(s->name, "sound/%s", name);
	271	else
	272	sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
	273
93fe4483 TH	274	if (!preclaim_oss) {
	275	/*
	276	* Something else might have grabbed the minor. If
	277	* first free slot is requested, rescan with @low set
	278	* to the next unit; otherwise, -EBUSY.
	279	*/
	280	r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name,
	281	&soundcore_fops);
	282	if (r < 0) {
	283	spin_lock(&sound_loader_lock);
	284	__sound_remove_unit(list, s->unit_minor);
	285	if (index < 0) {
	286	low = s->unit_minor + SOUND_STEP;
	287	goto retry;
	288	}
	289	spin_unlock(&sound_loader_lock);
	290	return -EBUSY;
	291	}
	292	}
	293
abe9ab8f GKH	294	device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
abe9ab8f GKH	295	NULL, s->name+6);
93fe4483	296	return s->unit_minor;
1da177e4	297
93fe4483	298	fail:
1da177e4 LT	299	kfree(s);
	300	return r;
	301	}
	302
	303	/*
	304	* Remove a unit. Acquires locks as needed. The drivers MUST have
	305	* completed the removal before their file operations become
	306	* invalid.
	307	*/
	308
	309	static void sound_remove_unit(struct sound_unit **list, int unit)
	310	{
	311	struct sound_unit *p;
	312
	313	spin_lock(&sound_loader_lock);
	314	p = __sound_remove_unit(list, unit);
	315	spin_unlock(&sound_loader_lock);
	316	if (p) {
93fe4483 TH	317	if (!preclaim_oss)
	318	__unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
	319	p->name);
d80f19fa	320	device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
1da177e4 LT	321	kfree(p);
	322	}
	323	}
	324
	325	/*
	326	* Allocations
	327	*
	328	* 0 *16 Mixers
	329	* 1 *8 Sequencers
	330	* 2 *16 Midi
	331	* 3 *16 DSP
	332	* 4 *16 SunDSP
	333	* 5 *16 DSP16
	334	* 6 -- sndstat (obsolete)
	335	* 7 *16 unused
	336	* 8 -- alternate sequencer (see above)
	337	* 9 *16 raw synthesizer access
	338	* 10 *16 unused
	339	* 11 *16 unused
	340	* 12 *16 unused
	341	* 13 *16 unused
	342	* 14 *16 unused
	343	* 15 *16 unused
	344	*/
	345
	346	static struct sound_unit *chains[SOUND_STEP];
	347
	348	/**
d568121c	349	* register_sound_special_device - register a special sound node
1da177e4 LT	350	* @fops: File operations for the driver
1da177e4 LT	351	* @unit: Unit number to allocate
d568121c	352	* @dev: device pointer
1da177e4 LT	353	*
1da177e4 LT	354	* Allocate a special sound device by minor number from the sound
eb7c06e8 YB	355	* subsystem.
	356	*
	357	* Return: The allocated number is returned on success. On failure,
1da177e4 LT	358	* a negative error code is returned.
	359	*/
	360
99ac48f5	361	int register_sound_special_device(const struct file_operations *fops, int unit,
d568121c	362	struct device *dev)
1da177e4 LT	363	{
1da177e4 LT	364	const int chain = unit % SOUND_STEP;
2abb8017	365	int max_unit = 256;
1da177e4 LT	366	const char *name;
	367	char _name[16];
	368
	369	switch (chain) {
	370	case 0:
	371	name = "mixer";
	372	break;
	373	case 1:
	374	name = "sequencer";
	375	if (unit >= SOUND_STEP)
	376	goto __unknown;
	377	max_unit = unit + 1;
	378	break;
	379	case 2:
	380	name = "midi";
	381	break;
	382	case 3:
	383	name = "dsp";
	384	break;
	385	case 4:
	386	name = "audio";
	387	break;
848669da TI	388	case 5:
	389	name = "dspW";
	390	break;
1da177e4 LT	391	case 8:
	392	name = "sequencer2";
	393	if (unit >= SOUND_STEP)
	394	goto __unknown;
	395	max_unit = unit + 1;
	396	break;
	397	case 9:
	398	name = "dmmidi";
	399	break;
	400	case 10:
	401	name = "dmfm";
	402	break;
	403	case 12:
	404	name = "adsp";
	405	break;
	406	case 13:
	407	name = "amidi";
	408	break;
	409	case 14:
	410	name = "admmidi";
	411	break;
	412	default:
	413	{
	414	__unknown:
	415	sprintf(_name, "unknown%d", chain);
	416	if (unit >= SOUND_STEP)
	417	strcat(_name, "-");
	418	name = _name;
	419	}
	420	break;
	421	}
	422	return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
d568121c	423	name, S_IRUSR \| S_IWUSR, dev);
1da177e4 LT	424	}
1da177e4 LT	425
d568121c TI	426	EXPORT_SYMBOL(register_sound_special_device);
d568121c TI	427
99ac48f5	428	int register_sound_special(const struct file_operations *fops, int unit)
d568121c TI	429	{
	430	return register_sound_special_device(fops, unit, NULL);
	431	}
	432
1da177e4 LT	433	EXPORT_SYMBOL(register_sound_special);
	434
	435	/**
	436	* register_sound_mixer - register a mixer device
	437	* @fops: File operations for the driver
	438	* @dev: Unit number to allocate
	439	*
	440	* Allocate a mixer device. Unit is the number of the mixer requested.
eb7c06e8 YB	441	* Pass -1 to request the next free mixer unit.
	442	*
	443	* Return: On success, the allocated number is returned. On failure,
	444	* a negative error code is returned.
1da177e4 LT	445	*/
1da177e4 LT	446
99ac48f5	447	int register_sound_mixer(const struct file_operations *fops, int dev)
1da177e4 LT	448	{
1da177e4 LT	449	return sound_insert_unit(&chains[0], fops, dev, 0, 128,
d568121c	450	"mixer", S_IRUSR \| S_IWUSR, NULL);
1da177e4 LT	451	}
	452
	453	EXPORT_SYMBOL(register_sound_mixer);
	454
	455	/**
	456	* register_sound_midi - register a midi device
	457	* @fops: File operations for the driver
	458	* @dev: Unit number to allocate
	459	*
	460	* Allocate a midi device. Unit is the number of the midi device requested.
eb7c06e8 YB	461	* Pass -1 to request the next free midi unit.
	462	*
	463	* Return: On success, the allocated number is returned. On failure,
	464	* a negative error code is returned.
1da177e4 LT	465	*/
1da177e4 LT	466
99ac48f5	467	int register_sound_midi(const struct file_operations *fops, int dev)
1da177e4 LT	468	{
1da177e4 LT	469	return sound_insert_unit(&chains[2], fops, dev, 2, 130,
d568121c	470	"midi", S_IRUSR \| S_IWUSR, NULL);
1da177e4 LT	471	}
	472
	473	EXPORT_SYMBOL(register_sound_midi);
	474
	475	/*
	476	* DSP's are registered as a triple. Register only one and cheat
	477	* in open - see below.
	478	*/
	479
	480	/**
	481	* register_sound_dsp - register a DSP device
	482	* @fops: File operations for the driver
	483	* @dev: Unit number to allocate
	484	*
	485	* Allocate a DSP device. Unit is the number of the DSP requested.
eb7c06e8	486	* Pass -1 to request the next free DSP unit.
1da177e4 LT	487	*
	488	* This function allocates both the audio and dsp device entries together
	489	* and will always allocate them as a matching pair - eg dsp3/audio3
eb7c06e8 YB	490	*
	491	* Return: On success, the allocated number is returned. On failure,
	492	* a negative error code is returned.
1da177e4 LT	493	*/
1da177e4 LT	494
99ac48f5	495	int register_sound_dsp(const struct file_operations *fops, int dev)
1da177e4 LT	496	{
1da177e4 LT	497	return sound_insert_unit(&chains[3], fops, dev, 3, 131,
d568121c	498	"dsp", S_IWUSR \| S_IRUSR, NULL);
1da177e4 LT	499	}
	500
	501	EXPORT_SYMBOL(register_sound_dsp);
	502
1da177e4 LT	503	/**
	504	* unregister_sound_special - unregister a special sound device
	505	* @unit: unit number to allocate
	506	*
	507	* Release a sound device that was allocated with
	508	* register_sound_special(). The unit passed is the return value from
	509	* the register function.
	510	*/
	511
	512
	513	void unregister_sound_special(int unit)
	514	{
	515	sound_remove_unit(&chains[unit % SOUND_STEP], unit);
	516	}
	517
	518	EXPORT_SYMBOL(unregister_sound_special);
	519
	520	/**
	521	* unregister_sound_mixer - unregister a mixer
	522	* @unit: unit number to allocate
	523	*
	524	* Release a sound device that was allocated with register_sound_mixer().
	525	* The unit passed is the return value from the register function.
	526	*/
	527
	528	void unregister_sound_mixer(int unit)
	529	{
	530	sound_remove_unit(&chains[0], unit);
	531	}
	532
	533	EXPORT_SYMBOL(unregister_sound_mixer);
	534
	535	/**
	536	* unregister_sound_midi - unregister a midi device
	537	* @unit: unit number to allocate
	538	*
	539	* Release a sound device that was allocated with register_sound_midi().
	540	* The unit passed is the return value from the register function.
	541	*/
	542
	543	void unregister_sound_midi(int unit)
	544	{
a39c4ad1	545	sound_remove_unit(&chains[2], unit);
1da177e4 LT	546	}
	547
	548	EXPORT_SYMBOL(unregister_sound_midi);
	549
	550	/**
	551	* unregister_sound_dsp - unregister a DSP device
	552	* @unit: unit number to allocate
	553	*
	554	* Release a sound device that was allocated with register_sound_dsp().
	555	* The unit passed is the return value from the register function.
	556	*
	557	* Both of the allocated units are released together automatically.
	558	*/
	559
	560	void unregister_sound_dsp(int unit)
	561	{
a39c4ad1	562	sound_remove_unit(&chains[3], unit);
1da177e4 LT	563	}
	564
	565
	566	EXPORT_SYMBOL(unregister_sound_dsp);
	567
1da177e4 LT	568	static struct sound_unit *__look_for_unit(int chain, int unit)
	569	{
	570	struct sound_unit *s;
	571
	572	s=chains[chain];
	573	while(s && s->unit_minor <= unit)
	574	{
	575	if(s->unit_minor==unit)
	576	return s;
	577	s=s->next;
	578	}
	579	return NULL;
	580	}
	581
a39c4ad1	582	static int soundcore_open(struct inode inode, struct file file)
1da177e4 LT	583	{
	584	int chain;
	585	int unit = iminor(inode);
	586	struct sound_unit *s;
99ac48f5	587	const struct file_operations *new_fops = NULL;
1da177e4 LT	588
	589	chain=unit&0x0F;
	590	if(chain==4 \|\| chain==5) /* dsp/audio/dsp16 */
	591	{
	592	unit&=0xF0;
	593	unit\|=3;
	594	chain=3;
	595	}
	596
	597	spin_lock(&sound_loader_lock);
	598	s = __look_for_unit(chain, unit);
	599	if (s)
	600	new_fops = fops_get(s->unit_fops);
93fe4483	601	if (preclaim_oss && !new_fops) {
1da177e4	602	spin_unlock(&sound_loader_lock);
0a848680	603
1da177e4 LT	604	/*
	605	* Please, don't change this order or code.
	606	* For ALSA slot means soundcard and OSS emulation code
	607	* comes as add-on modules which aren't depend on
	608	* ALSA toplevel modules for soundcards, thus we need
	609	* load them at first. [Jaroslav Kysela <perex@jcu.cz>]
	610	*/
	611	request_module("sound-slot-%i", unit>>4);
	612	request_module("sound-service-%i-%i", unit>>4, chain);
0a848680 TH	613
	614	/*
	615	* sound-slot/service-* module aliases are scheduled
	616	* for removal in favor of the standard char-major-*
	617	* module aliases. For the time being, generate both
	618	* the legacy and standard module aliases to ease
	619	* transition.
	620	*/
	621	if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
	622	request_module("char-major-%d", SOUND_MAJOR);
	623
1da177e4 LT	624	spin_lock(&sound_loader_lock);
	625	s = __look_for_unit(chain, unit);
	626	if (s)
	627	new_fops = fops_get(s->unit_fops);
	628	}
	629	if (new_fops) {
	630	/*
	631	* We rely upon the fact that we can't be unloaded while the
	632	* subdriver is there, so if ->open() is successful we can
	633	* safely drop the reference counter and if it is not we can
	634	* revert to old ->f_op. Ugly, indeed, but that's the cost of
	635	* switching ->f_op in the first place.
	636	*/
	637	int err = 0;
99ac48f5	638	const struct file_operations *old_fops = file->f_op;
1da177e4 LT	639	file->f_op = new_fops;
1da177e4 LT	640	spin_unlock(&sound_loader_lock);
171d9f7d	641
90dc763f	642	if (file->f_op->open)
1da177e4	643	err = file->f_op->open(inode,file);
171d9f7d	644
1da177e4 LT	645	if (err) {
	646	fops_put(file->f_op);
	647	file->f_op = fops_get(old_fops);
	648	}
171d9f7d	649
1da177e4 LT	650	fops_put(old_fops);
	651	return err;
	652	}
	653	spin_unlock(&sound_loader_lock);
	654	return -ENODEV;
	655	}
	656
1da177e4 LT	657	MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
1da177e4 LT	658
de30d36b	659	static void cleanup_oss_soundcore(void)
1da177e4 LT	660	{
	661	/* We have nothing to really do here - we know the lists must be
	662	empty */
	663	unregister_chrdev(SOUND_MAJOR, "sound");
1da177e4 LT	664	}
1da177e4 LT	665
d886e87c	666	static int __init init_oss_soundcore(void)
1da177e4	667	{
93fe4483 TH	668	if (preclaim_oss &&
93fe4483 TH	669	register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) == -1) {
1da177e4 LT	670	printk(KERN_ERR "soundcore: sound device already in use.\n");
	671	return -EBUSY;
	672	}
1da177e4 LT	673
	674	return 0;
	675	}
	676
d886e87c	677	#endif /* CONFIG_SOUND_OSS_CORE */