[PATCH] x86_64: use halt() instead of raw inline assembly
[wrt350n-kernel.git] / sound / core / device.c
blob6ce4da4a1081995317c79523c22bfefd63786529
1 /*
2 * Device management routines
3 * Copyright (c) by Jaroslav Kysela <perex@suse.cz>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include <sound/driver.h>
23 #include <linux/slab.h>
24 #include <linux/time.h>
25 #include <linux/errno.h>
26 #include <sound/core.h>
28 /**
29 * snd_device_new - create an ALSA device component
30 * @card: the card instance
31 * @type: the device type, SNDRV_DEV_XXX
32 * @device_data: the data pointer of this device
33 * @ops: the operator table
35 * Creates a new device component for the given data pointer.
36 * The device will be assigned to the card and managed together
37 * by the card.
39 * The data pointer plays a role as the identifier, too, so the
40 * pointer address must be unique and unchanged.
42 * Returns zero if successful, or a negative error code on failure.
44 int snd_device_new(struct snd_card *card, snd_device_type_t type,
45 void *device_data, struct snd_device_ops *ops)
47 struct snd_device *dev;
49 snd_assert(card != NULL, return -ENXIO);
50 snd_assert(device_data != NULL, return -ENXIO);
51 snd_assert(ops != NULL, return -ENXIO);
52 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
53 if (dev == NULL) {
54 snd_printk(KERN_ERR "Cannot allocate device\n");
55 return -ENOMEM;
57 dev->card = card;
58 dev->type = type;
59 dev->state = SNDRV_DEV_BUILD;
60 dev->device_data = device_data;
61 dev->ops = ops;
62 list_add(&dev->list, &card->devices); /* add to the head of list */
63 return 0;
66 EXPORT_SYMBOL(snd_device_new);
68 /**
69 * snd_device_free - release the device from the card
70 * @card: the card instance
71 * @device_data: the data pointer to release
73 * Removes the device from the list on the card and invokes the
74 * callback, dev_unregister or dev_free, corresponding to the state.
75 * Then release the device.
77 * Returns zero if successful, or a negative error code on failure or if the
78 * device not found.
80 int snd_device_free(struct snd_card *card, void *device_data)
82 struct list_head *list;
83 struct snd_device *dev;
85 snd_assert(card != NULL, return -ENXIO);
86 snd_assert(device_data != NULL, return -ENXIO);
87 list_for_each(list, &card->devices) {
88 dev = snd_device(list);
89 if (dev->device_data != device_data)
90 continue;
91 /* unlink */
92 list_del(&dev->list);
93 if ((dev->state == SNDRV_DEV_REGISTERED ||
94 dev->state == SNDRV_DEV_DISCONNECTED) &&
95 dev->ops->dev_unregister) {
96 if (dev->ops->dev_unregister(dev))
97 snd_printk(KERN_ERR "device unregister failure\n");
98 } else {
99 if (dev->ops->dev_free) {
100 if (dev->ops->dev_free(dev))
101 snd_printk(KERN_ERR "device free failure\n");
104 kfree(dev);
105 return 0;
107 snd_printd("device free %p (from %p), not found\n", device_data,
108 __builtin_return_address(0));
109 return -ENXIO;
112 EXPORT_SYMBOL(snd_device_free);
115 * snd_device_disconnect - disconnect the device
116 * @card: the card instance
117 * @device_data: the data pointer to disconnect
119 * Turns the device into the disconnection state, invoking
120 * dev_disconnect callback, if the device was already registered.
122 * Usually called from snd_card_disconnect().
124 * Returns zero if successful, or a negative error code on failure or if the
125 * device not found.
127 int snd_device_disconnect(struct snd_card *card, void *device_data)
129 struct list_head *list;
130 struct snd_device *dev;
132 snd_assert(card != NULL, return -ENXIO);
133 snd_assert(device_data != NULL, return -ENXIO);
134 list_for_each(list, &card->devices) {
135 dev = snd_device(list);
136 if (dev->device_data != device_data)
137 continue;
138 if (dev->state == SNDRV_DEV_REGISTERED &&
139 dev->ops->dev_disconnect) {
140 if (dev->ops->dev_disconnect(dev))
141 snd_printk(KERN_ERR "device disconnect failure\n");
142 dev->state = SNDRV_DEV_DISCONNECTED;
144 return 0;
146 snd_printd("device disconnect %p (from %p), not found\n", device_data,
147 __builtin_return_address(0));
148 return -ENXIO;
152 * snd_device_register - register the device
153 * @card: the card instance
154 * @device_data: the data pointer to register
156 * Registers the device which was already created via
157 * snd_device_new(). Usually this is called from snd_card_register(),
158 * but it can be called later if any new devices are created after
159 * invocation of snd_card_register().
161 * Returns zero if successful, or a negative error code on failure or if the
162 * device not found.
164 int snd_device_register(struct snd_card *card, void *device_data)
166 struct list_head *list;
167 struct snd_device *dev;
168 int err;
170 snd_assert(card != NULL, return -ENXIO);
171 snd_assert(device_data != NULL, return -ENXIO);
172 list_for_each(list, &card->devices) {
173 dev = snd_device(list);
174 if (dev->device_data != device_data)
175 continue;
176 if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
177 if ((err = dev->ops->dev_register(dev)) < 0)
178 return err;
179 dev->state = SNDRV_DEV_REGISTERED;
180 return 0;
182 snd_printd("snd_device_register busy\n");
183 return -EBUSY;
185 snd_BUG();
186 return -ENXIO;
189 EXPORT_SYMBOL(snd_device_register);
192 * register all the devices on the card.
193 * called from init.c
195 int snd_device_register_all(struct snd_card *card)
197 struct list_head *list;
198 struct snd_device *dev;
199 int err;
201 snd_assert(card != NULL, return -ENXIO);
202 list_for_each(list, &card->devices) {
203 dev = snd_device(list);
204 if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
205 if ((err = dev->ops->dev_register(dev)) < 0)
206 return err;
207 dev->state = SNDRV_DEV_REGISTERED;
210 return 0;
214 * disconnect all the devices on the card.
215 * called from init.c
217 int snd_device_disconnect_all(struct snd_card *card)
219 struct snd_device *dev;
220 struct list_head *list;
221 int err = 0;
223 snd_assert(card != NULL, return -ENXIO);
224 list_for_each(list, &card->devices) {
225 dev = snd_device(list);
226 if (snd_device_disconnect(card, dev->device_data) < 0)
227 err = -ENXIO;
229 return err;
233 * release all the devices on the card.
234 * called from init.c
236 int snd_device_free_all(struct snd_card *card, snd_device_cmd_t cmd)
238 struct snd_device *dev;
239 struct list_head *list;
240 int err;
241 unsigned int range_low, range_high;
243 snd_assert(card != NULL, return -ENXIO);
244 range_low = cmd * SNDRV_DEV_TYPE_RANGE_SIZE;
245 range_high = range_low + SNDRV_DEV_TYPE_RANGE_SIZE - 1;
246 __again:
247 list_for_each(list, &card->devices) {
248 dev = snd_device(list);
249 if (dev->type >= range_low && dev->type <= range_high) {
250 if ((err = snd_device_free(card, dev->device_data)) < 0)
251 return err;
252 goto __again;
255 return 0;