fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / sound / core / device.c
blobea1a0621eefb6680ccd885b014005281ad455820
1 /*
2 * Device management routines
3 * Copyright (c) by Jaroslav Kysela <perex@perex.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 * callbacks, dev_disconnect and 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 snd_device *dev;
84 snd_assert(card != NULL, return -ENXIO);
85 snd_assert(device_data != NULL, return -ENXIO);
86 list_for_each_entry(dev, &card->devices, list) {
87 if (dev->device_data != device_data)
88 continue;
89 /* unlink */
90 list_del(&dev->list);
91 if (dev->state == SNDRV_DEV_REGISTERED &&
92 dev->ops->dev_disconnect)
93 if (dev->ops->dev_disconnect(dev))
94 snd_printk(KERN_ERR
95 "device disconnect failure\n");
96 if (dev->ops->dev_free) {
97 if (dev->ops->dev_free(dev))
98 snd_printk(KERN_ERR "device free failure\n");
100 kfree(dev);
101 return 0;
103 snd_printd("device free %p (from %p), not found\n", device_data,
104 __builtin_return_address(0));
105 return -ENXIO;
108 EXPORT_SYMBOL(snd_device_free);
111 * snd_device_disconnect - disconnect the device
112 * @card: the card instance
113 * @device_data: the data pointer to disconnect
115 * Turns the device into the disconnection state, invoking
116 * dev_disconnect callback, if the device was already registered.
118 * Usually called from snd_card_disconnect().
120 * Returns zero if successful, or a negative error code on failure or if the
121 * device not found.
123 int snd_device_disconnect(struct snd_card *card, void *device_data)
125 struct snd_device *dev;
127 snd_assert(card != NULL, return -ENXIO);
128 snd_assert(device_data != NULL, return -ENXIO);
129 list_for_each_entry(dev, &card->devices, list) {
130 if (dev->device_data != device_data)
131 continue;
132 if (dev->state == SNDRV_DEV_REGISTERED &&
133 dev->ops->dev_disconnect) {
134 if (dev->ops->dev_disconnect(dev))
135 snd_printk(KERN_ERR "device disconnect failure\n");
136 dev->state = SNDRV_DEV_DISCONNECTED;
138 return 0;
140 snd_printd("device disconnect %p (from %p), not found\n", device_data,
141 __builtin_return_address(0));
142 return -ENXIO;
146 * snd_device_register - register the device
147 * @card: the card instance
148 * @device_data: the data pointer to register
150 * Registers the device which was already created via
151 * snd_device_new(). Usually this is called from snd_card_register(),
152 * but it can be called later if any new devices are created after
153 * invocation of snd_card_register().
155 * Returns zero if successful, or a negative error code on failure or if the
156 * device not found.
158 int snd_device_register(struct snd_card *card, void *device_data)
160 struct snd_device *dev;
161 int err;
163 snd_assert(card != NULL, return -ENXIO);
164 snd_assert(device_data != NULL, return -ENXIO);
165 list_for_each_entry(dev, &card->devices, list) {
166 if (dev->device_data != device_data)
167 continue;
168 if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
169 if ((err = dev->ops->dev_register(dev)) < 0)
170 return err;
171 dev->state = SNDRV_DEV_REGISTERED;
172 return 0;
174 snd_printd("snd_device_register busy\n");
175 return -EBUSY;
177 snd_BUG();
178 return -ENXIO;
181 EXPORT_SYMBOL(snd_device_register);
184 * register all the devices on the card.
185 * called from init.c
187 int snd_device_register_all(struct snd_card *card)
189 struct snd_device *dev;
190 int err;
192 snd_assert(card != NULL, return -ENXIO);
193 list_for_each_entry(dev, &card->devices, list) {
194 if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
195 if ((err = dev->ops->dev_register(dev)) < 0)
196 return err;
197 dev->state = SNDRV_DEV_REGISTERED;
200 return 0;
204 * disconnect all the devices on the card.
205 * called from init.c
207 int snd_device_disconnect_all(struct snd_card *card)
209 struct snd_device *dev;
210 int err = 0;
212 snd_assert(card != NULL, return -ENXIO);
213 list_for_each_entry(dev, &card->devices, list) {
214 if (snd_device_disconnect(card, dev->device_data) < 0)
215 err = -ENXIO;
217 return err;
221 * release all the devices on the card.
222 * called from init.c
224 int snd_device_free_all(struct snd_card *card, snd_device_cmd_t cmd)
226 struct snd_device *dev;
227 int err;
228 unsigned int range_low, range_high;
230 snd_assert(card != NULL, return -ENXIO);
231 range_low = cmd * SNDRV_DEV_TYPE_RANGE_SIZE;
232 range_high = range_low + SNDRV_DEV_TYPE_RANGE_SIZE - 1;
233 __again:
234 list_for_each_entry(dev, &card->devices, list) {
235 if (dev->type >= range_low && dev->type <= range_high) {
236 if ((err = snd_device_free(card, dev->device_data)) < 0)
237 return err;
238 goto __again;
241 return 0;