[linux-2.6-block.git] / sound / core / seq / seq_device.c

/*
 *  ALSA sequencer device management
 *  Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de>
 *
 *   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.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 *
 *----------------------------------------------------------------
 *
 * This device handler separates the card driver module from sequencer
 * stuff (sequencer core, synth drivers, etc), so that user can avoid
 * to spend unnecessary resources e.g. if he needs only listening to
 * MP3s.
 *
 * The card (or lowlevel) driver creates a sequencer device entry
 * via snd_seq_device_new().  This is an entry pointer to communicate
 * with the sequencer device "driver", which is involved with the
 * actual part to communicate with the sequencer core.
 * Each sequencer device entry has an id string and the corresponding
 * driver with the same id is loaded when required.  For example,
 * lowlevel codes to access emu8000 chip on sbawe card are included in
 * emu8000-synth module.  To activate this module, the hardware
 * resources like i/o port are passed via snd_seq_device argument.
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/info.h>
#include <sound/seq_device.h>
#include <sound/seq_kernel.h>
#include <sound/initval.h>
#include <linux/kmod.h>
#include <linux/slab.h>
#include <linux/mutex.h>

MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
MODULE_DESCRIPTION("ALSA sequencer device management");
MODULE_LICENSE("GPL");

/* driver state */
#define DRIVER_EMPTY		0
#define DRIVER_LOADED		(1<<0)
#define DRIVER_REQUESTED	(1<<1)
#define DRIVER_LOCKED		(1<<2)

struct ops_list {
	char id[ID_LEN];	/* driver id */
	int driver;		/* driver state */
	int used;		/* reference counter */
	int argsize;		/* argument size */

	/* operators */
	struct snd_seq_dev_ops ops;

	/* registered devices */
	struct list_head dev_list;	/* list of devices */
	int num_devices;	/* number of associated devices */
	int num_init_devices;	/* number of initialized devices */
	struct mutex reg_mutex;

	struct list_head list;	/* next driver */
};


static LIST_HEAD(opslist);
static int num_ops;
static DEFINE_MUTEX(ops_mutex);
#ifdef CONFIG_PROC_FS
static struct snd_info_entry *info_entry;
#endif

/*
 * prototypes
 */
static int snd_seq_device_free(struct snd_seq_device *dev);
static int snd_seq_device_dev_free(struct snd_device *device);
static int snd_seq_device_dev_register(struct snd_device *device);
static int snd_seq_device_dev_disconnect(struct snd_device *device);

static int init_device(struct snd_seq_device *dev, struct ops_list *ops);
static int free_device(struct snd_seq_device *dev, struct ops_list *ops);
static struct ops_list *find_driver(char *id, int create_if_empty);
static struct ops_list *create_driver(char *id);
static void unlock_driver(struct ops_list *ops);
static void remove_drivers(void);

/*
 * show all drivers and their status
 */

#ifdef CONFIG_PROC_FS
static void snd_seq_device_info(struct snd_info_entry *entry,
				struct snd_info_buffer *buffer)
{
	struct ops_list *ops;

	mutex_lock(&ops_mutex);
	list_for_each_entry(ops, &opslist, list) {
		snd_iprintf(buffer, "snd-%s%s%s%s,%d\n",
				ops->id,
				ops->driver & DRIVER_LOADED ? ",loaded" : (ops->driver == DRIVER_EMPTY ? ",empty" : ""),
				ops->driver & DRIVER_REQUESTED ? ",requested" : "",
				ops->driver & DRIVER_LOCKED ? ",locked" : "",
				ops->num_devices);
	}
	mutex_unlock(&ops_mutex);
}
#endif
 
/*
 * load all registered drivers (called from seq_clientmgr.c)
 */

#ifdef CONFIG_MODULES
/* avoid auto-loading during module_init() */
static int snd_seq_in_init;
void snd_seq_autoload_lock(void)
{
	snd_seq_in_init++;
}

void snd_seq_autoload_unlock(void)
{
	snd_seq_in_init--;
}
#endif

void snd_seq_device_load_drivers(void)
{
#ifdef CONFIG_MODULES
	struct ops_list *ops;

	/* Calling request_module during module_init()
	 * may cause blocking.
	 */
	if (snd_seq_in_init)
		return;

	mutex_lock(&ops_mutex);
	list_for_each_entry(ops, &opslist, list) {
		if (! (ops->driver & DRIVER_LOADED) &&
		    ! (ops->driver & DRIVER_REQUESTED)) {
			ops->used++;
			mutex_unlock(&ops_mutex);
			ops->driver |= DRIVER_REQUESTED;
			request_module("snd-%s", ops->id);
			mutex_lock(&ops_mutex);
			ops->used--;
		}
	}
	mutex_unlock(&ops_mutex);
#endif
}

/*
 * register a sequencer device
 * card = card info (NULL allowed)
 * device = device number (if any)
 * id = id of driver
 * result = return pointer (NULL allowed if unnecessary)
 */
int snd_seq_device_new(struct snd_card *card, int device, char *id, int argsize,
		       struct snd_seq_device **result)
{
	struct snd_seq_device *dev;
	struct ops_list *ops;
	int err;
	static struct snd_device_ops dops = {
		.dev_free = snd_seq_device_dev_free,
		.dev_register = snd_seq_device_dev_register,
		.dev_disconnect = snd_seq_device_dev_disconnect,
	};

	if (result)
		*result = NULL;

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

	ops = find_driver(id, 1);
	if (ops == NULL)
		return -ENOMEM;

	dev = kzalloc(sizeof(*dev)*2 + argsize, GFP_KERNEL);
	if (dev == NULL) {
		unlock_driver(ops);
		return -ENOMEM;
	}

	/* set up device info */
	dev->card = card;
	dev->device = device;
	strlcpy(dev->id, id, sizeof(dev->id));
	dev->argsize = argsize;
	dev->status = SNDRV_SEQ_DEVICE_FREE;

	/* add this device to the list */
	mutex_lock(&ops->reg_mutex);
	list_add_tail(&dev->list, &ops->dev_list);
	ops->num_devices++;
	mutex_unlock(&ops->reg_mutex);

	unlock_driver(ops);
	
	if ((err = snd_device_new(card, SNDRV_DEV_SEQUENCER, dev, &dops)) < 0) {
		snd_seq_device_free(dev);
		return err;
	}
	
	if (result)
		*result = dev;

	return 0;
}

/*
 * free the existing device
 */
static int snd_seq_device_free(struct snd_seq_device *dev)
{
	struct ops_list *ops;

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

	ops = find_driver(dev->id, 0);
	if (ops == NULL)
		return -ENXIO;

	/* remove the device from the list */
	mutex_lock(&ops->reg_mutex);
	list_del(&dev->list);
	ops->num_devices--;
	mutex_unlock(&ops->reg_mutex);

	free_device(dev, ops);
	if (dev->private_free)
		dev->private_free(dev);
	kfree(dev);

	unlock_driver(ops);

	return 0;
}

static int snd_seq_device_dev_free(struct snd_device *device)
{
	struct snd_seq_device *dev = device->device_data;
	return snd_seq_device_free(dev);
}

/*
 * register the device
 */
static int snd_seq_device_dev_register(struct snd_device *device)
{
	struct snd_seq_device *dev = device->device_data;
	struct ops_list *ops;

	ops = find_driver(dev->id, 0);
	if (ops == NULL)
		return -ENOENT;

	/* initialize this device if the corresponding driver was
	 * already loaded
	 */
	if (ops->driver & DRIVER_LOADED)
		init_device(dev, ops);

	unlock_driver(ops);
	return 0;
}

/*
 * disconnect the device
 */
static int snd_seq_device_dev_disconnect(struct snd_device *device)
{
	struct snd_seq_device *dev = device->device_data;
	struct ops_list *ops;

	ops = find_driver(dev->id, 0);
	if (ops == NULL)
		return -ENOENT;

	free_device(dev, ops);

	unlock_driver(ops);
	return 0;
}

/*
 * register device driver
 * id = driver id
 * entry = driver operators - duplicated to each instance
 */
int snd_seq_device_register_driver(char *id, struct snd_seq_dev_ops *entry,
				   int argsize)
{
	struct ops_list *ops;
	struct snd_seq_device *dev;

	if (id == NULL || entry == NULL ||
	    entry->init_device == NULL || entry->free_device == NULL)
		return -EINVAL;

	snd_seq_autoload_lock();
	ops = find_driver(id, 1);
	if (ops == NULL) {
		snd_seq_autoload_unlock();
		return -ENOMEM;
	}
	if (ops->driver & DRIVER_LOADED) {
		snd_printk(KERN_WARNING "driver_register: driver '%s' already exists\n", id);
		unlock_driver(ops);
		snd_seq_autoload_unlock();
		return -EBUSY;
	}

	mutex_lock(&ops->reg_mutex);
	/* copy driver operators */
	ops->ops = *entry;
	ops->driver |= DRIVER_LOADED;
	ops->argsize = argsize;

	/* initialize existing devices if necessary */
	list_for_each_entry(dev, &ops->dev_list, list) {
		init_device(dev, ops);
	}
	mutex_unlock(&ops->reg_mutex);

	unlock_driver(ops);
	snd_seq_autoload_unlock();

	return 0;
}


/*
 * create driver record
 */
static struct ops_list * create_driver(char *id)
{
	struct ops_list *ops;

	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
	if (ops == NULL)
		return ops;

	/* set up driver entry */
	strlcpy(ops->id, id, sizeof(ops->id));
	mutex_init(&ops->reg_mutex);
	/*
	 * The ->reg_mutex locking rules are per-driver, so we create
	 * separate per-driver lock classes:
	 */
	lockdep_set_class(&ops->reg_mutex, (struct lock_class_key *)id);

	ops->driver = DRIVER_EMPTY;
	INIT_LIST_HEAD(&ops->dev_list);
	/* lock this instance */
	ops->used = 1;

	/* register driver entry */
	mutex_lock(&ops_mutex);
	list_add_tail(&ops->list, &opslist);
	num_ops++;
	mutex_unlock(&ops_mutex);

	return ops;
}


/*
 * unregister the specified driver
 */
int snd_seq_device_unregister_driver(char *id)
{
	struct ops_list *ops;
	struct snd_seq_device *dev;

	ops = find_driver(id, 0);
	if (ops == NULL)
		return -ENXIO;
	if (! (ops->driver & DRIVER_LOADED) ||
	    (ops->driver & DRIVER_LOCKED)) {
		snd_printk(KERN_ERR "driver_unregister: cannot unload driver '%s': status=%x\n",
			   id, ops->driver);
		unlock_driver(ops);
		return -EBUSY;
	}

	/* close and release all devices associated with this driver */
	mutex_lock(&ops->reg_mutex);
	ops->driver |= DRIVER_LOCKED; /* do not remove this driver recursively */
	list_for_each_entry(dev, &ops->dev_list, list) {
		free_device(dev, ops);
	}

	ops->driver = 0;
	if (ops->num_init_devices > 0)
		snd_printk(KERN_ERR "free_driver: init_devices > 0!! (%d)\n",
			   ops->num_init_devices);
	mutex_unlock(&ops->reg_mutex);

	unlock_driver(ops);

	/* remove empty driver entries */
	remove_drivers();

	return 0;
}


/*
 * remove empty driver entries
 */
static void remove_drivers(void)
{
	struct list_head *head;

	mutex_lock(&ops_mutex);
	head = opslist.next;
	while (head != &opslist) {
		struct ops_list *ops = list_entry(head, struct ops_list, list);
		if (! (ops->driver & DRIVER_LOADED) &&
		    ops->used == 0 && ops->num_devices == 0) {
			head = head->next;
			list_del(&ops->list);
			kfree(ops);
			num_ops--;
		} else
			head = head->next;
	}
	mutex_unlock(&ops_mutex);
}

/*
 * initialize the device - call init_device operator
 */
static int init_device(struct snd_seq_device *dev, struct ops_list *ops)
{
	if (! (ops->driver & DRIVER_LOADED))
		return 0; /* driver is not loaded yet */
	if (dev->status != SNDRV_SEQ_DEVICE_FREE)
		return 0; /* already initialized */
	if (ops->argsize != dev->argsize) {
		snd_printk(KERN_ERR "incompatible device '%s' for plug-in '%s' (%d %d)\n",
			   dev->name, ops->id, ops->argsize, dev->argsize);
		return -EINVAL;
	}
	if (ops->ops.init_device(dev) >= 0) {
		dev->status = SNDRV_SEQ_DEVICE_REGISTERED;
		ops->num_init_devices++;
	} else {
		snd_printk(KERN_ERR "init_device failed: %s: %s\n",
			   dev->name, dev->id);
	}

	return 0;
}

/*
 * release the device - call free_device operator
 */
static int free_device(struct snd_seq_device *dev, struct ops_list *ops)
{
	int result;

	if (! (ops->driver & DRIVER_LOADED))
		return 0; /* driver is not loaded yet */
	if (dev->status != SNDRV_SEQ_DEVICE_REGISTERED)
		return 0; /* not registered */
	if (ops->argsize != dev->argsize) {
		snd_printk(KERN_ERR "incompatible device '%s' for plug-in '%s' (%d %d)\n",
			   dev->name, ops->id, ops->argsize, dev->argsize);
		return -EINVAL;
	}
	if ((result = ops->ops.free_device(dev)) >= 0 || result == -ENXIO) {
		dev->status = SNDRV_SEQ_DEVICE_FREE;
		dev->driver_data = NULL;
		ops->num_init_devices--;
	} else {
		snd_printk(KERN_ERR "free_device failed: %s: %s\n",
			   dev->name, dev->id);
	}

	return 0;
}

/*
 * find the matching driver with given id
 */
static struct ops_list * find_driver(char *id, int create_if_empty)
{
	struct ops_list *ops;

	mutex_lock(&ops_mutex);
	list_for_each_entry(ops, &opslist, list) {
		if (strcmp(ops->id, id) == 0) {
			ops->used++;
			mutex_unlock(&ops_mutex);
			return ops;
		}
	}
	mutex_unlock(&ops_mutex);
	if (create_if_empty)
		return create_driver(id);
	return NULL;
}

static void unlock_driver(struct ops_list *ops)
{
	mutex_lock(&ops_mutex);
	ops->used--;
	mutex_unlock(&ops_mutex);
}


/*
 * module part
 */

static int __init alsa_seq_device_init(void)
{
#ifdef CONFIG_PROC_FS
	info_entry = snd_info_create_module_entry(THIS_MODULE, "drivers",
						  snd_seq_root);
	if (info_entry == NULL)
		return -ENOMEM;
	info_entry->content = SNDRV_INFO_CONTENT_TEXT;
	info_entry->c.text.read = snd_seq_device_info;
	if (snd_info_register(info_entry) < 0) {
		snd_info_free_entry(info_entry);
		return -ENOMEM;
	}
#endif
	return 0;
}

static void __exit alsa_seq_device_exit(void)
{
	remove_drivers();
#ifdef CONFIG_PROC_FS
	snd_info_free_entry(info_entry);
#endif
	if (num_ops)
		snd_printk(KERN_ERR "drivers not released (%d)\n", num_ops);
}

module_init(alsa_seq_device_init)
module_exit(alsa_seq_device_exit)

EXPORT_SYMBOL(snd_seq_device_load_drivers);
EXPORT_SYMBOL(snd_seq_device_new);
EXPORT_SYMBOL(snd_seq_device_register_driver);
EXPORT_SYMBOL(snd_seq_device_unregister_driver);
#ifdef CONFIG_MODULES
EXPORT_SYMBOL(snd_seq_autoload_lock);
EXPORT_SYMBOL(snd_seq_autoload_unlock);
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* ALSA sequencer device management
	3	* Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation; either version 2 of the License, or
	8	* (at your option) any later version.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	18	*
	19	*
	20	*----------------------------------------------------------------
	21	*
	22	* This device handler separates the card driver module from sequencer
	23	* stuff (sequencer core, synth drivers, etc), so that user can avoid
	24	* to spend unnecessary resources e.g. if he needs only listening to
	25	* MP3s.
	26	*
	27	* The card (or lowlevel) driver creates a sequencer device entry
	28	* via snd_seq_device_new(). This is an entry pointer to communicate
	29	* with the sequencer device "driver", which is involved with the
	30	* actual part to communicate with the sequencer core.
	31	* Each sequencer device entry has an id string and the corresponding
	32	* driver with the same id is loaded when required. For example,
	33	* lowlevel codes to access emu8000 chip on sbawe card are included in
	34	* emu8000-synth module. To activate this module, the hardware
	35	* resources like i/o port are passed via snd_seq_device argument.
	36	*
	37	*/
	38
1da177e4	39	#include <linux/init.h>
da155d5b	40	#include <linux/module.h>
1da177e4 LT	41	#include <sound/core.h>
	42	#include <sound/info.h>
	43	#include <sound/seq_device.h>
	44	#include <sound/seq_kernel.h>
	45	#include <sound/initval.h>
	46	#include <linux/kmod.h>
	47	#include <linux/slab.h>
1a60d4c5	48	#include <linux/mutex.h>
1da177e4 LT	49
	50	MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
	51	MODULE_DESCRIPTION("ALSA sequencer device management");
	52	MODULE_LICENSE("GPL");
	53
1da177e4 LT	54	/* driver state */
	55	#define DRIVER_EMPTY 0
	56	#define DRIVER_LOADED (1<<0)
	57	#define DRIVER_REQUESTED (1<<1)
	58	#define DRIVER_LOCKED (1<<2)
	59
	60	struct ops_list {
	61	char id[ID_LEN]; /* driver id */
	62	int driver; /* driver state */
	63	int used; /* reference counter */
	64	int argsize; /* argument size */
	65
	66	/* operators */
c7e0b5bf	67	struct snd_seq_dev_ops ops;
1da177e4	68
d93cf068	69	/* registered devices */
1da177e4 LT	70	struct list_head dev_list; /* list of devices */
	71	int num_devices; /* number of associated devices */
	72	int num_init_devices; /* number of initialized devices */
1a60d4c5	73	struct mutex reg_mutex;
1da177e4 LT	74
	75	struct list_head list; /* next driver */
	76	};
	77
	78
	79	static LIST_HEAD(opslist);
	80	static int num_ops;
1a60d4c5	81	static DEFINE_MUTEX(ops_mutex);
04f141a8	82	#ifdef CONFIG_PROC_FS
6581f4e7	83	static struct snd_info_entry *info_entry;
04f141a8	84	#endif
1da177e4 LT	85
	86	/*
	87	* prototypes
	88	*/
c7e0b5bf TI	89	static int snd_seq_device_free(struct snd_seq_device *dev);
	90	static int snd_seq_device_dev_free(struct snd_device *device);
	91	static int snd_seq_device_dev_register(struct snd_device *device);
	92	static int snd_seq_device_dev_disconnect(struct snd_device *device);
c7e0b5bf TI	93
	94	static int init_device(struct snd_seq_device dev, struct ops_list ops);
	95	static int free_device(struct snd_seq_device dev, struct ops_list ops);
	96	static struct ops_list find_driver(char id, int create_if_empty);
	97	static struct ops_list create_driver(char id);
	98	static void unlock_driver(struct ops_list *ops);
1da177e4 LT	99	static void remove_drivers(void);
	100
	101	/*
	102	* show all drivers and their status
	103	*/
	104
04f141a8	105	#ifdef CONFIG_PROC_FS
c7e0b5bf TI	106	static void snd_seq_device_info(struct snd_info_entry *entry,
c7e0b5bf TI	107	struct snd_info_buffer *buffer)
1da177e4	108	{
9244b2c3	109	struct ops_list *ops;
1da177e4	110
1a60d4c5	111	mutex_lock(&ops_mutex);
9244b2c3	112	list_for_each_entry(ops, &opslist, list) {
1da177e4 LT	113	snd_iprintf(buffer, "snd-%s%s%s%s,%d\n",
	114	ops->id,
	115	ops->driver & DRIVER_LOADED ? ",loaded" : (ops->driver == DRIVER_EMPTY ? ",empty" : ""),
	116	ops->driver & DRIVER_REQUESTED ? ",requested" : "",
	117	ops->driver & DRIVER_LOCKED ? ",locked" : "",
	118	ops->num_devices);
	119	}
1a60d4c5	120	mutex_unlock(&ops_mutex);
1da177e4	121	}
04f141a8	122	#endif
1da177e4 LT	123
	124	/*
	125	* load all registered drivers (called from seq_clientmgr.c)
	126	*/
	127
ee2da997	128	#ifdef CONFIG_MODULES
1da177e4 LT	129	/* avoid auto-loading during module_init() */
	130	static int snd_seq_in_init;
	131	void snd_seq_autoload_lock(void)
	132	{
	133	snd_seq_in_init++;
	134	}
	135
	136	void snd_seq_autoload_unlock(void)
	137	{
	138	snd_seq_in_init--;
	139	}
	140	#endif
	141
	142	void snd_seq_device_load_drivers(void)
	143	{
ee2da997	144	#ifdef CONFIG_MODULES
9244b2c3	145	struct ops_list *ops;
1da177e4 LT	146
	147	/* Calling request_module during module_init()
	148	* may cause blocking.
	149	*/
	150	if (snd_seq_in_init)
	151	return;
	152
1a60d4c5	153	mutex_lock(&ops_mutex);
9244b2c3	154	list_for_each_entry(ops, &opslist, list) {
1da177e4 LT	155	if (! (ops->driver & DRIVER_LOADED) &&
	156	! (ops->driver & DRIVER_REQUESTED)) {
	157	ops->used++;
1a60d4c5	158	mutex_unlock(&ops_mutex);
1da177e4 LT	159	ops->driver \|= DRIVER_REQUESTED;
1da177e4 LT	160	request_module("snd-%s", ops->id);
1a60d4c5	161	mutex_lock(&ops_mutex);
1da177e4 LT	162	ops->used--;
	163	}
	164	}
1a60d4c5	165	mutex_unlock(&ops_mutex);
1da177e4 LT	166	#endif
	167	}
	168
	169	/*
	170	* register a sequencer device
	171	* card = card info (NULL allowed)
	172	* device = device number (if any)
	173	* id = id of driver
	174	* result = return pointer (NULL allowed if unnecessary)
	175	*/
c7e0b5bf TI	176	int snd_seq_device_new(struct snd_card card, int device, char id, int argsize,
c7e0b5bf TI	177	struct snd_seq_device **result)
1da177e4	178	{
c7e0b5bf TI	179	struct snd_seq_device *dev;
c7e0b5bf TI	180	struct ops_list *ops;
1da177e4	181	int err;
c7e0b5bf	182	static struct snd_device_ops dops = {
1da177e4 LT	183	.dev_free = snd_seq_device_dev_free,
	184	.dev_register = snd_seq_device_dev_register,
	185	.dev_disconnect = snd_seq_device_dev_disconnect,
1da177e4 LT	186	};
	187
	188	if (result)
	189	*result = NULL;
	190
7eaa943c TI	191	if (snd_BUG_ON(!id))
7eaa943c TI	192	return -EINVAL;
1da177e4 LT	193
	194	ops = find_driver(id, 1);
	195	if (ops == NULL)
	196	return -ENOMEM;
	197
ecca82b4	198	dev = kzalloc(sizeof(dev)2 + argsize, GFP_KERNEL);
1da177e4 LT	199	if (dev == NULL) {
	200	unlock_driver(ops);
	201	return -ENOMEM;
	202	}
	203
	204	/* set up device info */
	205	dev->card = card;
	206	dev->device = device;
	207	strlcpy(dev->id, id, sizeof(dev->id));
	208	dev->argsize = argsize;
	209	dev->status = SNDRV_SEQ_DEVICE_FREE;
	210
	211	/* add this device to the list */
1a60d4c5	212	mutex_lock(&ops->reg_mutex);
1da177e4 LT	213	list_add_tail(&dev->list, &ops->dev_list);
1da177e4 LT	214	ops->num_devices++;
1a60d4c5	215	mutex_unlock(&ops->reg_mutex);
1da177e4 LT	216
	217	unlock_driver(ops);
	218
	219	if ((err = snd_device_new(card, SNDRV_DEV_SEQUENCER, dev, &dops)) < 0) {
	220	snd_seq_device_free(dev);
	221	return err;
	222	}
	223
	224	if (result)
	225	*result = dev;
	226
	227	return 0;
	228	}
	229
	230	/*
	231	* free the existing device
	232	*/
c7e0b5bf	233	static int snd_seq_device_free(struct snd_seq_device *dev)
1da177e4	234	{
c7e0b5bf	235	struct ops_list *ops;
1da177e4	236
7eaa943c TI	237	if (snd_BUG_ON(!dev))
7eaa943c TI	238	return -EINVAL;
1da177e4 LT	239
	240	ops = find_driver(dev->id, 0);
	241	if (ops == NULL)
	242	return -ENXIO;
	243
	244	/* remove the device from the list */
1a60d4c5	245	mutex_lock(&ops->reg_mutex);
1da177e4 LT	246	list_del(&dev->list);
1da177e4 LT	247	ops->num_devices--;
1a60d4c5	248	mutex_unlock(&ops->reg_mutex);
1da177e4 LT	249
	250	free_device(dev, ops);
	251	if (dev->private_free)
	252	dev->private_free(dev);
	253	kfree(dev);
	254
	255	unlock_driver(ops);
	256
	257	return 0;
	258	}
	259
c7e0b5bf	260	static int snd_seq_device_dev_free(struct snd_device *device)
1da177e4	261	{
c7e0b5bf	262	struct snd_seq_device *dev = device->device_data;
1da177e4 LT	263	return snd_seq_device_free(dev);
	264	}
	265
	266	/*
	267	* register the device
	268	*/
c7e0b5bf	269	static int snd_seq_device_dev_register(struct snd_device *device)
1da177e4	270	{
c7e0b5bf TI	271	struct snd_seq_device *dev = device->device_data;
c7e0b5bf TI	272	struct ops_list *ops;
1da177e4 LT	273
	274	ops = find_driver(dev->id, 0);
	275	if (ops == NULL)
	276	return -ENOENT;
	277
	278	/* initialize this device if the corresponding driver was
	279	* already loaded
	280	*/
	281	if (ops->driver & DRIVER_LOADED)
	282	init_device(dev, ops);
	283
	284	unlock_driver(ops);
	285	return 0;
	286	}
	287
	288	/*
	289	* disconnect the device
	290	*/
c7e0b5bf	291	static int snd_seq_device_dev_disconnect(struct snd_device *device)
1da177e4	292	{
c7e0b5bf TI	293	struct snd_seq_device *dev = device->device_data;
c7e0b5bf TI	294	struct ops_list *ops;
1da177e4 LT	295
	296	ops = find_driver(dev->id, 0);
	297	if (ops == NULL)
	298	return -ENOENT;
	299
	300	free_device(dev, ops);
	301
	302	unlock_driver(ops);
	303	return 0;
	304	}
	305
1da177e4 LT	306	/*
	307	* register device driver
	308	* id = driver id
	309	* entry = driver operators - duplicated to each instance
	310	*/
c7e0b5bf TI	311	int snd_seq_device_register_driver(char id, struct snd_seq_dev_ops entry,
c7e0b5bf TI	312	int argsize)
1da177e4	313	{
c7e0b5bf	314	struct ops_list *ops;
9244b2c3	315	struct snd_seq_device *dev;
1da177e4 LT	316
	317	if (id == NULL \|\| entry == NULL \|\|
	318	entry->init_device == NULL \|\| entry->free_device == NULL)
	319	return -EINVAL;
	320
	321	snd_seq_autoload_lock();
	322	ops = find_driver(id, 1);
	323	if (ops == NULL) {
	324	snd_seq_autoload_unlock();
	325	return -ENOMEM;
	326	}
	327	if (ops->driver & DRIVER_LOADED) {
	328	snd_printk(KERN_WARNING "driver_register: driver '%s' already exists\n", id);
	329	unlock_driver(ops);
	330	snd_seq_autoload_unlock();
	331	return -EBUSY;
	332	}
	333
1a60d4c5	334	mutex_lock(&ops->reg_mutex);
1da177e4 LT	335	/* copy driver operators */
	336	ops->ops = *entry;
	337	ops->driver \|= DRIVER_LOADED;
	338	ops->argsize = argsize;
	339
	340	/* initialize existing devices if necessary */
9244b2c3	341	list_for_each_entry(dev, &ops->dev_list, list) {
1da177e4 LT	342	init_device(dev, ops);
1da177e4 LT	343	}
1a60d4c5	344	mutex_unlock(&ops->reg_mutex);
1da177e4 LT	345
	346	unlock_driver(ops);
	347	snd_seq_autoload_unlock();
	348
	349	return 0;
	350	}
	351
	352
	353	/*
	354	* create driver record
	355	*/
c7e0b5bf	356	static struct ops_list * create_driver(char *id)
1da177e4	357	{
c7e0b5bf	358	struct ops_list *ops;
1da177e4	359
59feddb2	360	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
1da177e4 LT	361	if (ops == NULL)
1da177e4 LT	362	return ops;
1da177e4 LT	363
	364	/* set up driver entry */
	365	strlcpy(ops->id, id, sizeof(ops->id));
1a60d4c5	366	mutex_init(&ops->reg_mutex);
933a2efc AV	367	/*
	368	* The ->reg_mutex locking rules are per-driver, so we create
	369	* separate per-driver lock classes:
	370	*/
	371	lockdep_set_class(&ops->reg_mutex, (struct lock_class_key *)id);
	372
1da177e4 LT	373	ops->driver = DRIVER_EMPTY;
	374	INIT_LIST_HEAD(&ops->dev_list);
	375	/* lock this instance */
	376	ops->used = 1;
	377
	378	/* register driver entry */
1a60d4c5	379	mutex_lock(&ops_mutex);
1da177e4 LT	380	list_add_tail(&ops->list, &opslist);
1da177e4 LT	381	num_ops++;
1a60d4c5	382	mutex_unlock(&ops_mutex);
1da177e4 LT	383
	384	return ops;
	385	}
	386
	387
	388	/*
	389	* unregister the specified driver
	390	*/
	391	int snd_seq_device_unregister_driver(char *id)
	392	{
c7e0b5bf	393	struct ops_list *ops;
9244b2c3	394	struct snd_seq_device *dev;
1da177e4 LT	395
	396	ops = find_driver(id, 0);
	397	if (ops == NULL)
	398	return -ENXIO;
	399	if (! (ops->driver & DRIVER_LOADED) \|\|
	400	(ops->driver & DRIVER_LOCKED)) {
c7e0b5bf TI	401	snd_printk(KERN_ERR "driver_unregister: cannot unload driver '%s': status=%x\n",
c7e0b5bf TI	402	id, ops->driver);
1da177e4 LT	403	unlock_driver(ops);
	404	return -EBUSY;
	405	}
	406
	407	/* close and release all devices associated with this driver */
1a60d4c5	408	mutex_lock(&ops->reg_mutex);
1da177e4	409	ops->driver \|= DRIVER_LOCKED; /* do not remove this driver recursively */
9244b2c3	410	list_for_each_entry(dev, &ops->dev_list, list) {
1da177e4 LT	411	free_device(dev, ops);
	412	}
	413
	414	ops->driver = 0;
	415	if (ops->num_init_devices > 0)
c7e0b5bf TI	416	snd_printk(KERN_ERR "free_driver: init_devices > 0!! (%d)\n",
c7e0b5bf TI	417	ops->num_init_devices);
1a60d4c5	418	mutex_unlock(&ops->reg_mutex);
1da177e4 LT	419
	420	unlock_driver(ops);
	421
	422	/* remove empty driver entries */
	423	remove_drivers();
	424
	425	return 0;
	426	}
	427
	428
	429	/*
	430	* remove empty driver entries
	431	*/
	432	static void remove_drivers(void)
	433	{
	434	struct list_head *head;
	435
1a60d4c5	436	mutex_lock(&ops_mutex);
1da177e4 LT	437	head = opslist.next;
1da177e4 LT	438	while (head != &opslist) {
c7e0b5bf	439	struct ops_list *ops = list_entry(head, struct ops_list, list);
1da177e4 LT	440	if (! (ops->driver & DRIVER_LOADED) &&
	441	ops->used == 0 && ops->num_devices == 0) {
	442	head = head->next;
	443	list_del(&ops->list);
	444	kfree(ops);
	445	num_ops--;
	446	} else
	447	head = head->next;
	448	}
1a60d4c5	449	mutex_unlock(&ops_mutex);
1da177e4 LT	450	}
	451
	452	/*
	453	* initialize the device - call init_device operator
	454	*/
c7e0b5bf	455	static int init_device(struct snd_seq_device dev, struct ops_list ops)
1da177e4 LT	456	{
	457	if (! (ops->driver & DRIVER_LOADED))
	458	return 0; /* driver is not loaded yet */
	459	if (dev->status != SNDRV_SEQ_DEVICE_FREE)
	460	return 0; /* already initialized */
	461	if (ops->argsize != dev->argsize) {
c7e0b5bf TI	462	snd_printk(KERN_ERR "incompatible device '%s' for plug-in '%s' (%d %d)\n",
c7e0b5bf TI	463	dev->name, ops->id, ops->argsize, dev->argsize);
1da177e4 LT	464	return -EINVAL;
	465	}
	466	if (ops->ops.init_device(dev) >= 0) {
	467	dev->status = SNDRV_SEQ_DEVICE_REGISTERED;
	468	ops->num_init_devices++;
	469	} else {
c7e0b5bf TI	470	snd_printk(KERN_ERR "init_device failed: %s: %s\n",
c7e0b5bf TI	471	dev->name, dev->id);
1da177e4 LT	472	}
	473
	474	return 0;
	475	}
	476
	477	/*
	478	* release the device - call free_device operator
	479	*/
c7e0b5bf	480	static int free_device(struct snd_seq_device dev, struct ops_list ops)
1da177e4 LT	481	{
	482	int result;
	483
	484	if (! (ops->driver & DRIVER_LOADED))
	485	return 0; /* driver is not loaded yet */
	486	if (dev->status != SNDRV_SEQ_DEVICE_REGISTERED)
	487	return 0; /* not registered */
	488	if (ops->argsize != dev->argsize) {
c7e0b5bf TI	489	snd_printk(KERN_ERR "incompatible device '%s' for plug-in '%s' (%d %d)\n",
c7e0b5bf TI	490	dev->name, ops->id, ops->argsize, dev->argsize);
1da177e4 LT	491	return -EINVAL;
	492	}
	493	if ((result = ops->ops.free_device(dev)) >= 0 \|\| result == -ENXIO) {
	494	dev->status = SNDRV_SEQ_DEVICE_FREE;
	495	dev->driver_data = NULL;
	496	ops->num_init_devices--;
	497	} else {
c7e0b5bf TI	498	snd_printk(KERN_ERR "free_device failed: %s: %s\n",
c7e0b5bf TI	499	dev->name, dev->id);
1da177e4 LT	500	}
	501
	502	return 0;
	503	}
	504
	505	/*
	506	* find the matching driver with given id
	507	*/
c7e0b5bf	508	static struct ops_list * find_driver(char *id, int create_if_empty)
1da177e4	509	{
9244b2c3	510	struct ops_list *ops;
1da177e4	511
1a60d4c5	512	mutex_lock(&ops_mutex);
9244b2c3	513	list_for_each_entry(ops, &opslist, list) {
1da177e4 LT	514	if (strcmp(ops->id, id) == 0) {
1da177e4 LT	515	ops->used++;
1a60d4c5	516	mutex_unlock(&ops_mutex);
1da177e4 LT	517	return ops;
	518	}
	519	}
1a60d4c5	520	mutex_unlock(&ops_mutex);
1da177e4 LT	521	if (create_if_empty)
	522	return create_driver(id);
	523	return NULL;
	524	}
	525
c7e0b5bf	526	static void unlock_driver(struct ops_list *ops)
1da177e4	527	{
1a60d4c5	528	mutex_lock(&ops_mutex);
1da177e4	529	ops->used--;
1a60d4c5	530	mutex_unlock(&ops_mutex);
1da177e4 LT	531	}
	532
	533
	534	/*
	535	* module part
	536	*/
	537
	538	static int __init alsa_seq_device_init(void)
	539	{
04f141a8	540	#ifdef CONFIG_PROC_FS
c7e0b5bf TI	541	info_entry = snd_info_create_module_entry(THIS_MODULE, "drivers",
c7e0b5bf TI	542	snd_seq_root);
1da177e4 LT	543	if (info_entry == NULL)
	544	return -ENOMEM;
	545	info_entry->content = SNDRV_INFO_CONTENT_TEXT;
1da177e4 LT	546	info_entry->c.text.read = snd_seq_device_info;
	547	if (snd_info_register(info_entry) < 0) {
	548	snd_info_free_entry(info_entry);
	549	return -ENOMEM;
	550	}
04f141a8	551	#endif
1da177e4 LT	552	return 0;
	553	}
	554
	555	static void __exit alsa_seq_device_exit(void)
	556	{
	557	remove_drivers();
04f141a8	558	#ifdef CONFIG_PROC_FS
746d4a02	559	snd_info_free_entry(info_entry);
04f141a8	560	#endif
1da177e4 LT	561	if (num_ops)
	562	snd_printk(KERN_ERR "drivers not released (%d)\n", num_ops);
	563	}
	564
	565	module_init(alsa_seq_device_init)
	566	module_exit(alsa_seq_device_exit)
	567
	568	EXPORT_SYMBOL(snd_seq_device_load_drivers);
	569	EXPORT_SYMBOL(snd_seq_device_new);
	570	EXPORT_SYMBOL(snd_seq_device_register_driver);
	571	EXPORT_SYMBOL(snd_seq_device_unregister_driver);
8dea9d38	572	#ifdef CONFIG_MODULES
1da177e4 LT	573	EXPORT_SYMBOL(snd_seq_autoload_lock);
1da177e4 LT	574	EXPORT_SYMBOL(snd_seq_autoload_unlock);
8dea9d38	575	#endif