2 * ALSA sequencer device management
3 * Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de>
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.
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.
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
20 *----------------------------------------------------------------
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
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.
39 #include <sound/driver.h>
40 #include <linux/init.h>
41 #include <sound/core.h>
42 #include <sound/info.h>
43 #include <sound/seq_device.h>
44 #include <sound/initval.h>
45 #include <linux/kmod.h>
46 #include <linux/slab.h>
48 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
49 MODULE_DESCRIPTION("ALSA sequencer device management");
50 MODULE_LICENSE("GPL");
51 MODULE_CLASSES("{sound}");
52 MODULE_SUPPORTED_DEVICE("sound");
57 typedef struct ops_list ops_list_t;
60 #define DRIVER_EMPTY 0
61 #define DRIVER_LOADED (1<<0)
62 #define DRIVER_REQUESTED (1<<1)
63 #define DRIVER_LOCKED (1<<2)
66 char id[ID_LEN]; /* driver id */
67 int driver; /* driver state */
68 int used; /* reference counter */
69 int argsize; /* argument size */
72 snd_seq_dev_ops_t ops;
74 /* registred devices */
75 struct list_head dev_list; /* list of devices */
76 int num_devices; /* number of associated devices */
77 int num_init_devices; /* number of initialized devices */
78 struct semaphore reg_mutex;
80 struct list_head list; /* next driver */
84 static LIST_HEAD(opslist);
86 static DECLARE_MUTEX(ops_mutex);
87 static snd_info_entry_t *info_entry = NULL;
92 static int snd_seq_device_free(snd_seq_device_t *dev);
93 static int snd_seq_device_dev_free(snd_device_t *device);
94 static int snd_seq_device_dev_register(snd_device_t *device);
95 static int snd_seq_device_dev_disconnect(snd_device_t *device);
96 static int snd_seq_device_dev_unregister(snd_device_t *device);
98 static int init_device(snd_seq_device_t *dev, ops_list_t *ops);
99 static int free_device(snd_seq_device_t *dev, ops_list_t *ops);
100 static ops_list_t *find_driver(char *id, int create_if_empty);
101 static ops_list_t *create_driver(char *id);
102 static void unlock_driver(ops_list_t *ops);
103 static void remove_drivers(void);
106 * show all drivers and their status
109 static void snd_seq_device_info(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
111 struct list_head *head;
114 list_for_each(head, &opslist) {
115 ops_list_t *ops = list_entry(head, ops_list_t, list);
116 snd_iprintf(buffer, "snd-%s%s%s%s,%d\n",
118 ops->driver & DRIVER_LOADED ? ",loaded" : (ops->driver == DRIVER_EMPTY ? ",empty" : ""),
119 ops->driver & DRIVER_REQUESTED ? ",requested" : "",
120 ops->driver & DRIVER_LOCKED ? ",locked" : "",
127 * load all registered drivers (called from seq_clientmgr.c)
130 void snd_seq_device_load_drivers(void)
133 struct list_head *head;
135 if (! current->fs->root)
139 list_for_each(head, &opslist) {
140 ops_list_t *ops = list_entry(head, ops_list_t, list);
141 if (! (ops->driver & DRIVER_LOADED) &&
142 ! (ops->driver & DRIVER_REQUESTED)) {
145 ops->driver |= DRIVER_REQUESTED;
146 request_module("snd-%s", ops->id);
156 * register a sequencer device
157 * card = card info (NULL allowed)
158 * device = device number (if any)
160 * result = return pointer (NULL allowed if unnecessary)
162 int snd_seq_device_new(snd_card_t *card, int device, char *id, int argsize,
163 snd_seq_device_t **result)
165 snd_seq_device_t *dev;
168 static snd_device_ops_t dops = {
169 .dev_free = snd_seq_device_dev_free,
170 .dev_register = snd_seq_device_dev_register,
171 .dev_disconnect = snd_seq_device_dev_disconnect,
172 .dev_unregister = snd_seq_device_dev_unregister
178 snd_assert(id != NULL, return -EINVAL);
180 ops = find_driver(id, 1);
184 dev = snd_magic_kcalloc(snd_seq_device_t, sizeof(*dev) + argsize, GFP_KERNEL);
190 /* set up device info */
192 dev->device = device;
193 strlcpy(dev->id, id, sizeof(dev->id));
194 dev->argsize = argsize;
195 dev->status = SNDRV_SEQ_DEVICE_FREE;
197 /* add this device to the list */
198 down(&ops->reg_mutex);
199 list_add_tail(&dev->list, &ops->dev_list);
205 if ((err = snd_device_new(card, SNDRV_DEV_SEQUENCER, dev, &dops)) < 0) {
206 snd_seq_device_free(dev);
217 * free the existing device
219 static int snd_seq_device_free(snd_seq_device_t *dev)
223 snd_assert(dev != NULL, return -EINVAL);
225 ops = find_driver(dev->id, 0);
229 /* remove the device from the list */
230 down(&ops->reg_mutex);
231 list_del(&dev->list);
235 free_device(dev, ops);
236 if (dev->private_free)
237 dev->private_free(dev);
238 snd_magic_kfree(dev);
245 static int snd_seq_device_dev_free(snd_device_t *device)
247 snd_seq_device_t *dev = snd_magic_cast(snd_seq_device_t, device->device_data, return -ENXIO);
248 return snd_seq_device_free(dev);
252 * register the device
254 static int snd_seq_device_dev_register(snd_device_t *device)
256 snd_seq_device_t *dev = snd_magic_cast(snd_seq_device_t, device->device_data, return -ENXIO);
259 ops = find_driver(dev->id, 0);
263 /* initialize this device if the corresponding driver was
266 if (ops->driver & DRIVER_LOADED)
267 init_device(dev, ops);
274 * disconnect the device
276 static int snd_seq_device_dev_disconnect(snd_device_t *device)
278 snd_seq_device_t *dev = snd_magic_cast(snd_seq_device_t, device->device_data, return -ENXIO);
281 ops = find_driver(dev->id, 0);
285 free_device(dev, ops);
292 * unregister the existing device
294 static int snd_seq_device_dev_unregister(snd_device_t *device)
296 snd_seq_device_t *dev = snd_magic_cast(snd_seq_device_t, device->device_data, return -ENXIO);
297 return snd_seq_device_free(dev);
301 * register device driver
303 * entry = driver operators - duplicated to each instance
305 int snd_seq_device_register_driver(char *id, snd_seq_dev_ops_t *entry, int argsize)
307 struct list_head *head;
310 if (id == NULL || entry == NULL ||
311 entry->init_device == NULL || entry->free_device == NULL)
314 ops = find_driver(id, 1);
317 if (ops->driver & DRIVER_LOADED) {
318 snd_printk(KERN_WARNING "driver_register: driver '%s' already exists\n", id);
323 down(&ops->reg_mutex);
324 /* copy driver operators */
326 ops->driver |= DRIVER_LOADED;
327 ops->argsize = argsize;
329 /* initialize existing devices if necessary */
330 list_for_each(head, &ops->dev_list) {
331 snd_seq_device_t *dev = list_entry(head, snd_seq_device_t, list);
332 init_device(dev, ops);
343 * create driver record
345 static ops_list_t * create_driver(char *id)
349 ops = kmalloc(sizeof(*ops), GFP_KERNEL);
352 memset(ops, 0, sizeof(*ops));
354 /* set up driver entry */
355 strlcpy(ops->id, id, sizeof(ops->id));
356 init_MUTEX(&ops->reg_mutex);
357 ops->driver = DRIVER_EMPTY;
358 INIT_LIST_HEAD(&ops->dev_list);
359 /* lock this instance */
362 /* register driver entry */
364 list_add_tail(&ops->list, &opslist);
373 * unregister the specified driver
375 int snd_seq_device_unregister_driver(char *id)
377 struct list_head *head;
380 ops = find_driver(id, 0);
383 if (! (ops->driver & DRIVER_LOADED) ||
384 (ops->driver & DRIVER_LOCKED)) {
385 snd_printk(KERN_ERR "driver_unregister: cannot unload driver '%s': status=%x\n", id, ops->driver);
390 /* close and release all devices associated with this driver */
391 down(&ops->reg_mutex);
392 ops->driver |= DRIVER_LOCKED; /* do not remove this driver recursively */
393 list_for_each(head, &ops->dev_list) {
394 snd_seq_device_t *dev = list_entry(head, snd_seq_device_t, list);
395 free_device(dev, ops);
399 if (ops->num_init_devices > 0)
400 snd_printk(KERN_ERR "free_driver: init_devices > 0!! (%d)\n", ops->num_init_devices);
405 /* remove empty driver entries */
413 * remove empty driver entries
415 static void remove_drivers(void)
417 struct list_head *head;
421 while (head != &opslist) {
422 ops_list_t *ops = list_entry(head, ops_list_t, list);
423 if (! (ops->driver & DRIVER_LOADED) &&
424 ops->used == 0 && ops->num_devices == 0) {
426 list_del(&ops->list);
436 * initialize the device - call init_device operator
438 static int init_device(snd_seq_device_t *dev, ops_list_t *ops)
440 if (! (ops->driver & DRIVER_LOADED))
441 return 0; /* driver is not loaded yet */
442 if (dev->status != SNDRV_SEQ_DEVICE_FREE)
443 return 0; /* already initialized */
444 if (ops->argsize != dev->argsize) {
445 snd_printk(KERN_ERR "incompatible device '%s' for plug-in '%s' (%d %d)\n", dev->name, ops->id, ops->argsize, dev->argsize);
448 if (ops->ops.init_device(dev) >= 0) {
449 dev->status = SNDRV_SEQ_DEVICE_REGISTERED;
450 ops->num_init_devices++;
452 snd_printk(KERN_ERR "init_device failed: %s: %s\n", dev->name, dev->id);
459 * release the device - call free_device operator
461 static int free_device(snd_seq_device_t *dev, ops_list_t *ops)
465 if (! (ops->driver & DRIVER_LOADED))
466 return 0; /* driver is not loaded yet */
467 if (dev->status != SNDRV_SEQ_DEVICE_REGISTERED)
468 return 0; /* not registered */
469 if (ops->argsize != dev->argsize) {
470 snd_printk(KERN_ERR "incompatible device '%s' for plug-in '%s' (%d %d)\n", dev->name, ops->id, ops->argsize, dev->argsize);
473 if ((result = ops->ops.free_device(dev)) >= 0 || result == -ENXIO) {
474 dev->status = SNDRV_SEQ_DEVICE_FREE;
475 dev->driver_data = NULL;
476 ops->num_init_devices--;
478 snd_printk(KERN_ERR "free_device failed: %s: %s\n", dev->name, dev->id);
485 * find the matching driver with given id
487 static ops_list_t * find_driver(char *id, int create_if_empty)
489 struct list_head *head;
492 list_for_each(head, &opslist) {
493 ops_list_t *ops = list_entry(head, ops_list_t, list);
494 if (strcmp(ops->id, id) == 0) {
502 return create_driver(id);
506 static void unlock_driver(ops_list_t *ops)
518 static int __init alsa_seq_device_init(void)
520 info_entry = snd_info_create_module_entry(THIS_MODULE, "drivers", snd_seq_root);
521 if (info_entry == NULL)
523 info_entry->content = SNDRV_INFO_CONTENT_TEXT;
524 info_entry->c.text.read_size = 2048;
525 info_entry->c.text.read = snd_seq_device_info;
526 if (snd_info_register(info_entry) < 0) {
527 snd_info_free_entry(info_entry);
533 static void __exit alsa_seq_device_exit(void)
536 snd_info_unregister(info_entry);
538 snd_printk(KERN_ERR "drivers not released (%d)\n", num_ops);
541 module_init(alsa_seq_device_init)
542 module_exit(alsa_seq_device_exit)
544 EXPORT_SYMBOL(snd_seq_device_load_drivers);
545 EXPORT_SYMBOL(snd_seq_device_new);
546 EXPORT_SYMBOL(snd_seq_device_register_driver);
547 EXPORT_SYMBOL(snd_seq_device_unregister_driver);