ALSA: pcm - Fix unbalanced pm_qos_request
[linux-2.6.git] / sound / core / device.c
1 /*
2  *  Device management routines
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4  *
5  *
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.
10  *
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.
15  *
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
19  *
20  */
21
22 #include <linux/slab.h>
23 #include <linux/time.h>
24 #include <linux/errno.h>
25 #include <sound/core.h>
26
27 /**
28  * snd_device_new - create an ALSA device component
29  * @card: the card instance
30  * @type: the device type, SNDRV_DEV_XXX
31  * @device_data: the data pointer of this device
32  * @ops: the operator table
33  *
34  * Creates a new device component for the given data pointer.
35  * The device will be assigned to the card and managed together
36  * by the card.
37  *
38  * The data pointer plays a role as the identifier, too, so the
39  * pointer address must be unique and unchanged.
40  *
41  * Returns zero if successful, or a negative error code on failure.
42  */
43 int snd_device_new(struct snd_card *card, snd_device_type_t type,
44                    void *device_data, struct snd_device_ops *ops)
45 {
46         struct snd_device *dev;
47
48         if (snd_BUG_ON(!card || !device_data || !ops))
49                 return -ENXIO;
50         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
51         if (dev == NULL) {
52                 snd_printk(KERN_ERR "Cannot allocate device\n");
53                 return -ENOMEM;
54         }
55         dev->card = card;
56         dev->type = type;
57         dev->state = SNDRV_DEV_BUILD;
58         dev->device_data = device_data;
59         dev->ops = ops;
60         list_add(&dev->list, &card->devices);   /* add to the head of list */
61         return 0;
62 }
63
64 EXPORT_SYMBOL(snd_device_new);
65
66 /**
67  * snd_device_free - release the device from the card
68  * @card: the card instance
69  * @device_data: the data pointer to release
70  *
71  * Removes the device from the list on the card and invokes the
72  * callbacks, dev_disconnect and dev_free, corresponding to the state.
73  * Then release the device.
74  *
75  * Returns zero if successful, or a negative error code on failure or if the
76  * device not found.
77  */
78 int snd_device_free(struct snd_card *card, void *device_data)
79 {
80         struct snd_device *dev;
81         
82         if (snd_BUG_ON(!card || !device_data))
83                 return -ENXIO;
84         list_for_each_entry(dev, &card->devices, list) {
85                 if (dev->device_data != device_data)
86                         continue;
87                 /* unlink */
88                 list_del(&dev->list);
89                 if (dev->state == SNDRV_DEV_REGISTERED &&
90                     dev->ops->dev_disconnect)
91                         if (dev->ops->dev_disconnect(dev))
92                                 snd_printk(KERN_ERR
93                                            "device disconnect failure\n");
94                 if (dev->ops->dev_free) {
95                         if (dev->ops->dev_free(dev))
96                                 snd_printk(KERN_ERR "device free failure\n");
97                 }
98                 kfree(dev);
99                 return 0;
100         }
101         snd_printd("device free %p (from %pF), not found\n", device_data,
102                    __builtin_return_address(0));
103         return -ENXIO;
104 }
105
106 EXPORT_SYMBOL(snd_device_free);
107
108 /**
109  * snd_device_disconnect - disconnect the device
110  * @card: the card instance
111  * @device_data: the data pointer to disconnect
112  *
113  * Turns the device into the disconnection state, invoking
114  * dev_disconnect callback, if the device was already registered.
115  *
116  * Usually called from snd_card_disconnect().
117  *
118  * Returns zero if successful, or a negative error code on failure or if the
119  * device not found.
120  */
121 int snd_device_disconnect(struct snd_card *card, void *device_data)
122 {
123         struct snd_device *dev;
124
125         if (snd_BUG_ON(!card || !device_data))
126                 return -ENXIO;
127         list_for_each_entry(dev, &card->devices, list) {
128                 if (dev->device_data != device_data)
129                         continue;
130                 if (dev->state == SNDRV_DEV_REGISTERED &&
131                     dev->ops->dev_disconnect) {
132                         if (dev->ops->dev_disconnect(dev))
133                                 snd_printk(KERN_ERR "device disconnect failure\n");
134                         dev->state = SNDRV_DEV_DISCONNECTED;
135                 }
136                 return 0;
137         }
138         snd_printd("device disconnect %p (from %pF), not found\n", device_data,
139                    __builtin_return_address(0));
140         return -ENXIO;
141 }
142
143 /**
144  * snd_device_register - register the device
145  * @card: the card instance
146  * @device_data: the data pointer to register
147  *
148  * Registers the device which was already created via
149  * snd_device_new().  Usually this is called from snd_card_register(),
150  * but it can be called later if any new devices are created after
151  * invocation of snd_card_register().
152  *
153  * Returns zero if successful, or a negative error code on failure or if the
154  * device not found.
155  */
156 int snd_device_register(struct snd_card *card, void *device_data)
157 {
158         struct snd_device *dev;
159         int err;
160
161         if (snd_BUG_ON(!card || !device_data))
162                 return -ENXIO;
163         list_for_each_entry(dev, &card->devices, list) {
164                 if (dev->device_data != device_data)
165                         continue;
166                 if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
167                         if ((err = dev->ops->dev_register(dev)) < 0)
168                                 return err;
169                         dev->state = SNDRV_DEV_REGISTERED;
170                         return 0;
171                 }
172                 snd_printd("snd_device_register busy\n");
173                 return -EBUSY;
174         }
175         snd_BUG();
176         return -ENXIO;
177 }
178
179 EXPORT_SYMBOL(snd_device_register);
180
181 /*
182  * register all the devices on the card.
183  * called from init.c
184  */
185 int snd_device_register_all(struct snd_card *card)
186 {
187         struct snd_device *dev;
188         int err;
189         
190         if (snd_BUG_ON(!card))
191                 return -ENXIO;
192         list_for_each_entry(dev, &card->devices, list) {
193                 if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
194                         if ((err = dev->ops->dev_register(dev)) < 0)
195                                 return err;
196                         dev->state = SNDRV_DEV_REGISTERED;
197                 }
198         }
199         return 0;
200 }
201
202 /*
203  * disconnect all the devices on the card.
204  * called from init.c
205  */
206 int snd_device_disconnect_all(struct snd_card *card)
207 {
208         struct snd_device *dev;
209         int err = 0;
210
211         if (snd_BUG_ON(!card))
212                 return -ENXIO;
213         list_for_each_entry(dev, &card->devices, list) {
214                 if (snd_device_disconnect(card, dev->device_data) < 0)
215                         err = -ENXIO;
216         }
217         return err;
218 }
219
220 /*
221  * release all the devices on the card.
222  * called from init.c
223  */
224 int snd_device_free_all(struct snd_card *card, snd_device_cmd_t cmd)
225 {
226         struct snd_device *dev;
227         int err;
228         unsigned int range_low, range_high;
229
230         if (snd_BUG_ON(!card))
231                 return -ENXIO;
232         range_low = cmd * SNDRV_DEV_TYPE_RANGE_SIZE;
233         range_high = range_low + SNDRV_DEV_TYPE_RANGE_SIZE - 1;
234       __again:
235         list_for_each_entry(dev, &card->devices, list) {
236                 if (dev->type >= range_low && dev->type <= range_high) {
237                         if ((err = snd_device_free(card, dev->device_data)) < 0)
238                                 return err;
239                         goto __again;
240                 }
241         }
242         return 0;
243 }