Merge branch 'linux-3.4.57' into rel-17
[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/export.h>
25 #include <linux/errno.h>
26 #include <sound/core.h>
27
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
34  *
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.
38  *
39  * The data pointer plays a role as the identifier, too, so the
40  * pointer address must be unique and unchanged.
41  *
42  * Returns zero if successful, or a negative error code on failure.
43  */
44 int snd_device_new(struct snd_card *card, snd_device_type_t type,
45                    void *device_data, struct snd_device_ops *ops)
46 {
47         struct snd_device *dev;
48
49         if (snd_BUG_ON(!card || !device_data || !ops))
50                 return -ENXIO;
51         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
52         if (dev == NULL) {
53                 snd_printk(KERN_ERR "Cannot allocate device\n");
54                 return -ENOMEM;
55         }
56         dev->card = card;
57         dev->type = type;
58         dev->state = SNDRV_DEV_BUILD;
59         dev->device_data = device_data;
60         dev->ops = ops;
61         list_add(&dev->list, &card->devices);   /* add to the head of list */
62         return 0;
63 }
64
65 EXPORT_SYMBOL(snd_device_new);
66
67 /**
68  * snd_device_free - release the device from the card
69  * @card: the card instance
70  * @device_data: the data pointer to release
71  *
72  * Removes the device from the list on the card and invokes the
73  * callbacks, dev_disconnect and dev_free, corresponding to the state.
74  * Then release the device.
75  *
76  * Returns zero if successful, or a negative error code on failure or if the
77  * device not found.
78  */
79 int snd_device_free(struct snd_card *card, void *device_data)
80 {
81         struct snd_device *dev;
82         
83         if (snd_BUG_ON(!card || !device_data))
84                 return -ENXIO;
85         list_for_each_entry(dev, &card->devices, list) {
86                 if (dev->device_data != device_data)
87                         continue;
88                 /* unlink */
89                 list_del(&dev->list);
90                 if (dev->state == SNDRV_DEV_REGISTERED &&
91                     dev->ops->dev_disconnect)
92                         if (dev->ops->dev_disconnect(dev))
93                                 snd_printk(KERN_ERR
94                                            "device disconnect failure\n");
95                 if (dev->ops->dev_free) {
96                         if (dev->ops->dev_free(dev))
97                                 snd_printk(KERN_ERR "device free failure\n");
98                 }
99                 kfree(dev);
100                 return 0;
101         }
102         snd_printd("device free %p (from %pF), not found\n", device_data,
103                    __builtin_return_address(0));
104         return -ENXIO;
105 }
106
107 EXPORT_SYMBOL(snd_device_free);
108
109 /**
110  * snd_device_disconnect - disconnect the device
111  * @card: the card instance
112  * @device_data: the data pointer to disconnect
113  *
114  * Turns the device into the disconnection state, invoking
115  * dev_disconnect callback, if the device was already registered.
116  *
117  * Usually called from snd_card_disconnect().
118  *
119  * Returns zero if successful, or a negative error code on failure or if the
120  * device not found.
121  */
122 int snd_device_disconnect(struct snd_card *card, void *device_data)
123 {
124         struct snd_device *dev;
125
126         if (snd_BUG_ON(!card || !device_data))
127                 return -ENXIO;
128         list_for_each_entry(dev, &card->devices, list) {
129                 if (dev->device_data != device_data)
130                         continue;
131                 if (dev->state == SNDRV_DEV_REGISTERED &&
132                     dev->ops->dev_disconnect) {
133                         if (dev->ops->dev_disconnect(dev))
134                                 snd_printk(KERN_ERR "device disconnect failure\n");
135                         dev->state = SNDRV_DEV_DISCONNECTED;
136                 }
137                 return 0;
138         }
139         snd_printd("device disconnect %p (from %pF), not found\n", device_data,
140                    __builtin_return_address(0));
141         return -ENXIO;
142 }
143
144 /**
145  * snd_device_register - register the device
146  * @card: the card instance
147  * @device_data: the data pointer to register
148  *
149  * Registers the device which was already created via
150  * snd_device_new().  Usually this is called from snd_card_register(),
151  * but it can be called later if any new devices are created after
152  * invocation of snd_card_register().
153  *
154  * Returns zero if successful, or a negative error code on failure or if the
155  * device not found.
156  */
157 int snd_device_register(struct snd_card *card, void *device_data)
158 {
159         struct snd_device *dev;
160         int err;
161
162         if (snd_BUG_ON(!card || !device_data))
163                 return -ENXIO;
164         list_for_each_entry(dev, &card->devices, list) {
165                 if (dev->device_data != device_data)
166                         continue;
167                 if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
168                         if ((err = dev->ops->dev_register(dev)) < 0)
169                                 return err;
170                         dev->state = SNDRV_DEV_REGISTERED;
171                         return 0;
172                 }
173                 snd_printd("snd_device_register busy\n");
174                 return -EBUSY;
175         }
176         snd_BUG();
177         return -ENXIO;
178 }
179
180 EXPORT_SYMBOL(snd_device_register);
181
182 /*
183  * register all the devices on the card.
184  * called from init.c
185  */
186 int snd_device_register_all(struct snd_card *card)
187 {
188         struct snd_device *dev;
189         int err;
190         
191         if (snd_BUG_ON(!card))
192                 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;
198                 }
199         }
200         return 0;
201 }
202
203 /*
204  * disconnect all the devices on the card.
205  * called from init.c
206  */
207 int snd_device_disconnect_all(struct snd_card *card)
208 {
209         struct snd_device *dev;
210         int err = 0;
211
212         if (snd_BUG_ON(!card))
213                 return -ENXIO;
214         list_for_each_entry(dev, &card->devices, list) {
215                 if (snd_device_disconnect(card, dev->device_data) < 0)
216                         err = -ENXIO;
217         }
218         return err;
219 }
220
221 /*
222  * release all the devices on the card.
223  * called from init.c
224  */
225 int snd_device_free_all(struct snd_card *card, snd_device_cmd_t cmd)
226 {
227         struct snd_device *dev;
228         int err;
229         unsigned int range_low, range_high, type;
230
231         if (snd_BUG_ON(!card))
232                 return -ENXIO;
233         range_low = (__force unsigned int)cmd * SNDRV_DEV_TYPE_RANGE_SIZE;
234         range_high = range_low + SNDRV_DEV_TYPE_RANGE_SIZE - 1;
235       __again:
236         list_for_each_entry(dev, &card->devices, list) {
237                 type = (__force unsigned int)dev->type;
238                 if (type >= range_low && type <= range_high) {
239                         if ((err = snd_device_free(card, dev->device_data)) < 0)
240                                 return err;
241                         goto __again;
242                 }
243         }
244         return 0;
245 }