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");
55 typedef struct ops_list ops_list_t;
58 #define DRIVER_EMPTY 0
59 #define DRIVER_LOADED (1<<0)
60 #define DRIVER_REQUESTED (1<<1)
61 #define DRIVER_LOCKED (1<<2)
64 char id[ID_LEN]; /* driver id */
65 int driver; /* driver state */
66 int used; /* reference counter */
67 int argsize; /* argument size */
70 snd_seq_dev_ops_t ops;
72 /* registred devices */
73 struct list_head dev_list; /* list of devices */
74 int num_devices; /* number of associated devices */
75 int num_init_devices; /* number of initialized devices */
76 struct semaphore reg_mutex;
78 struct list_head list; /* next driver */
82 static LIST_HEAD(opslist);
84 static DECLARE_MUTEX(ops_mutex);
85 static snd_info_entry_t *info_entry = NULL;
90 static int snd_seq_device_free(snd_seq_device_t *dev);
91 static int snd_seq_device_dev_free(snd_device_t *device);
92 static int snd_seq_device_dev_register(snd_device_t *device);
93 static int snd_seq_device_dev_disconnect(snd_device_t *device);
94 static int snd_seq_device_dev_unregister(snd_device_t *device);
96 static int init_device(snd_seq_device_t *dev, ops_list_t *ops);
97 static int free_device(snd_seq_device_t *dev, ops_list_t *ops);
98 static ops_list_t *find_driver(char *id, int create_if_empty);
99 static ops_list_t *create_driver(char *id);
100 static void unlock_driver(ops_list_t *ops);
101 static void remove_drivers(void);
104 * show all drivers and their status
107 static void snd_seq_device_info(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
109 struct list_head *head;
112 list_for_each(head, &opslist) {
113 ops_list_t *ops = list_entry(head, ops_list_t, list);
114 snd_iprintf(buffer, "snd-%s%s%s%s,%d\n",
116 ops->driver & DRIVER_LOADED ? ",loaded" : (ops->driver == DRIVER_EMPTY ? ",empty" : ""),
117 ops->driver & DRIVER_REQUESTED ? ",requested" : "",
118 ops->driver & DRIVER_LOCKED ? ",locked" : "",
125 * load all registered drivers (called from seq_clientmgr.c)
128 void snd_seq_device_load_drivers(void)
131 struct list_head *head;
133 if (! current->fs->root)
137 list_for_each(head, &opslist) {
138 ops_list_t *ops = list_entry(head, ops_list_t, list);
139 if (! (ops->driver & DRIVER_LOADED) &&
140 ! (ops->driver & DRIVER_REQUESTED)) {
143 ops->driver |= DRIVER_REQUESTED;
144 request_module("snd-%s", ops->id);
154 * register a sequencer device
155 * card = card info (NULL allowed)
156 * device = device number (if any)
158 * result = return pointer (NULL allowed if unnecessary)
160 int snd_seq_device_new(snd_card_t *card, int device, char *id, int argsize,
161 snd_seq_device_t **result)
163 snd_seq_device_t *dev;
166 static snd_device_ops_t dops = {
167 .dev_free = snd_seq_device_dev_free,
168 .dev_register = snd_seq_device_dev_register,
169 .dev_disconnect = snd_seq_device_dev_disconnect,
170 .dev_unregister = snd_seq_device_dev_unregister
176 snd_assert(id != NULL, return -EINVAL);
178 ops = find_driver(id, 1);
182 dev = kcalloc(1, sizeof(*dev)*2 + argsize, GFP_KERNEL);
188 /* set up device info */
190 dev->device = device;
191 strlcpy(dev->id, id, sizeof(dev->id));
192 dev->argsize = argsize;
193 dev->status = SNDRV_SEQ_DEVICE_FREE;
195 /* add this device to the list */
196 down(&ops->reg_mutex);
197 list_add_tail(&dev->list, &ops->dev_list);
203 if ((err = snd_device_new(card, SNDRV_DEV_SEQUENCER, dev, &dops)) < 0) {
204 snd_seq_device_free(dev);
215 * free the existing device
217 static int snd_seq_device_free(snd_seq_device_t *dev)
221 snd_assert(dev != NULL, return -EINVAL);
223 ops = find_driver(dev->id, 0);
227 /* remove the device from the list */
228 down(&ops->reg_mutex);
229 list_del(&dev->list);
233 free_device(dev, ops);
234 if (dev->private_free)
235 dev->private_free(dev);
243 static int snd_seq_device_dev_free(snd_device_t *device)
245 snd_seq_device_t *dev = device->device_data;
246 return snd_seq_device_free(dev);
250 * register the device
252 static int snd_seq_device_dev_register(snd_device_t *device)
254 snd_seq_device_t *dev = device->device_data;
257 ops = find_driver(dev->id, 0);
261 /* initialize this device if the corresponding driver was
264 if (ops->driver & DRIVER_LOADED)
265 init_device(dev, ops);
272 * disconnect the device
274 static int snd_seq_device_dev_disconnect(snd_device_t *device)
276 snd_seq_device_t *dev = device->device_data;
279 ops = find_driver(dev->id, 0);
283 free_device(dev, ops);
290 * unregister the existing device
292 static int snd_seq_device_dev_unregister(snd_device_t *device)
294 snd_seq_device_t *dev = device->device_data;
295 return snd_seq_device_free(dev);
299 * register device driver
301 * entry = driver operators - duplicated to each instance
303 int snd_seq_device_register_driver(char *id, snd_seq_dev_ops_t *entry, int argsize)
305 struct list_head *head;
308 if (id == NULL || entry == NULL ||
309 entry->init_device == NULL || entry->free_device == NULL)
312 ops = find_driver(id, 1);
315 if (ops->driver & DRIVER_LOADED) {
316 snd_printk(KERN_WARNING "driver_register: driver '%s' already exists\n", id);
321 down(&ops->reg_mutex);
322 /* copy driver operators */
324 ops->driver |= DRIVER_LOADED;
325 ops->argsize = argsize;
327 /* initialize existing devices if necessary */
328 list_for_each(head, &ops->dev_list) {
329 snd_seq_device_t *dev = list_entry(head, snd_seq_device_t, list);
330 init_device(dev, ops);
341 * create driver record
343 static ops_list_t * create_driver(char *id)
347 ops = kmalloc(sizeof(*ops), GFP_KERNEL);
350 memset(ops, 0, sizeof(*ops));
352 /* set up driver entry */
353 strlcpy(ops->id, id, sizeof(ops->id));
354 init_MUTEX(&ops->reg_mutex);
355 ops->driver = DRIVER_EMPTY;
356 INIT_LIST_HEAD(&ops->dev_list);
357 /* lock this instance */
360 /* register driver entry */
362 list_add_tail(&ops->list, &opslist);
371 * unregister the specified driver
373 int snd_seq_device_unregister_driver(char *id)
375 struct list_head *head;
378 ops = find_driver(id, 0);
381 if (! (ops->driver & DRIVER_LOADED) ||
382 (ops->driver & DRIVER_LOCKED)) {
383 snd_printk(KERN_ERR "driver_unregister: cannot unload driver '%s': status=%x\n", id, ops->driver);
388 /* close and release all devices associated with this driver */
389 down(&ops->reg_mutex);
390 ops->driver |= DRIVER_LOCKED; /* do not remove this driver recursively */
391 list_for_each(head, &ops->dev_list) {
392 snd_seq_device_t *dev = list_entry(head, snd_seq_device_t, list);
393 free_device(dev, ops);
397 if (ops->num_init_devices > 0)
398 snd_printk(KERN_ERR "free_driver: init_devices > 0!! (%d)\n", ops->num_init_devices);
403 /* remove empty driver entries */
411 * remove empty driver entries
413 static void remove_drivers(void)
415 struct list_head *head;
419 while (head != &opslist) {
420 ops_list_t *ops = list_entry(head, ops_list_t, list);
421 if (! (ops->driver & DRIVER_LOADED) &&
422 ops->used == 0 && ops->num_devices == 0) {
424 list_del(&ops->list);
434 * initialize the device - call init_device operator
436 static int init_device(snd_seq_device_t *dev, ops_list_t *ops)
438 if (! (ops->driver & DRIVER_LOADED))
439 return 0; /* driver is not loaded yet */
440 if (dev->status != SNDRV_SEQ_DEVICE_FREE)
441 return 0; /* already initialized */
442 if (ops->argsize != dev->argsize) {
443 snd_printk(KERN_ERR "incompatible device '%s' for plug-in '%s' (%d %d)\n", dev->name, ops->id, ops->argsize, dev->argsize);
446 if (ops->ops.init_device(dev) >= 0) {
447 dev->status = SNDRV_SEQ_DEVICE_REGISTERED;
448 ops->num_init_devices++;
450 snd_printk(KERN_ERR "init_device failed: %s: %s\n", dev->name, dev->id);
457 * release the device - call free_device operator
459 static int free_device(snd_seq_device_t *dev, ops_list_t *ops)
463 if (! (ops->driver & DRIVER_LOADED))
464 return 0; /* driver is not loaded yet */
465 if (dev->status != SNDRV_SEQ_DEVICE_REGISTERED)
466 return 0; /* not registered */
467 if (ops->argsize != dev->argsize) {
468 snd_printk(KERN_ERR "incompatible device '%s' for plug-in '%s' (%d %d)\n", dev->name, ops->id, ops->argsize, dev->argsize);
471 if ((result = ops->ops.free_device(dev)) >= 0 || result == -ENXIO) {
472 dev->status = SNDRV_SEQ_DEVICE_FREE;
473 dev->driver_data = NULL;
474 ops->num_init_devices--;
476 snd_printk(KERN_ERR "free_device failed: %s: %s\n", dev->name, dev->id);
483 * find the matching driver with given id
485 static ops_list_t * find_driver(char *id, int create_if_empty)
487 struct list_head *head;
490 list_for_each(head, &opslist) {
491 ops_list_t *ops = list_entry(head, ops_list_t, list);
492 if (strcmp(ops->id, id) == 0) {
500 return create_driver(id);
504 static void unlock_driver(ops_list_t *ops)
516 static int __init alsa_seq_device_init(void)
518 info_entry = snd_info_create_module_entry(THIS_MODULE, "drivers", snd_seq_root);
519 if (info_entry == NULL)
521 info_entry->content = SNDRV_INFO_CONTENT_TEXT;
522 info_entry->c.text.read_size = 2048;
523 info_entry->c.text.read = snd_seq_device_info;
524 if (snd_info_register(info_entry) < 0) {
525 snd_info_free_entry(info_entry);
531 static void __exit alsa_seq_device_exit(void)
534 snd_info_unregister(info_entry);
536 snd_printk(KERN_ERR "drivers not released (%d)\n", num_ops);
539 module_init(alsa_seq_device_init)
540 module_exit(alsa_seq_device_exit)
542 EXPORT_SYMBOL(snd_seq_device_load_drivers);
543 EXPORT_SYMBOL(snd_seq_device_new);
544 EXPORT_SYMBOL(snd_seq_device_register_driver);
545 EXPORT_SYMBOL(snd_seq_device_unregister_driver);