[ALSA] Changed Jaroslav Kysela's e-mail from perex@suse.cz to perex@perex.cz
[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 <sound/driver.h>
23 #include <linux/slab.h>
24 #include <linux/time.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         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;
56         }
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;
64 }
65
66 EXPORT_SYMBOL(snd_device_new);
67
68 /**
69  * snd_device_free - release the device from the card
70  * @card: the card instance
71  * @device_data: the data pointer to release
72  *
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.
76  *
77  * Returns zero if successful, or a negative error code on failure or if the
78  * device not found.
79  */
80 int snd_device_free(struct snd_card *card, void *device_data)
81 {
82         struct snd_device *dev;
83         
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");
99                 }
100                 kfree(dev);
101                 return 0;
102         }
103         snd_printd("device free %p (from %p), not found\n", device_data,
104                    __builtin_return_address(0));
105         return -ENXIO;
106 }
107
108 EXPORT_SYMBOL(snd_device_free);
109
110 /**
111  * snd_device_disconnect - disconnect the device
112  * @card: the card instance
113  * @device_data: the data pointer to disconnect
114  *
115  * Turns the device into the disconnection state, invoking
116  * dev_disconnect callback, if the device was already registered.
117  *
118  * Usually called from snd_card_disconnect().
119  *
120  * Returns zero if successful, or a negative error code on failure or if the
121  * device not found.
122  */
123 int snd_device_disconnect(struct snd_card *card, void *device_data)
124 {
125         struct snd_device *dev;
126
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;
137                 }
138                 return 0;
139         }
140         snd_printd("device disconnect %p (from %p), not found\n", device_data,
141                    __builtin_return_address(0));
142         return -ENXIO;
143 }
144
145 /**
146  * snd_device_register - register the device
147  * @card: the card instance
148  * @device_data: the data pointer to register
149  *
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().
154  *
155  * Returns zero if successful, or a negative error code on failure or if the
156  * device not found.
157  */
158 int snd_device_register(struct snd_card *card, void *device_data)
159 {
160         struct snd_device *dev;
161         int err;
162
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;
173                 }
174                 snd_printd("snd_device_register busy\n");
175                 return -EBUSY;
176         }
177         snd_BUG();
178         return -ENXIO;
179 }
180
181 EXPORT_SYMBOL(snd_device_register);
182
183 /*
184  * register all the devices on the card.
185  * called from init.c
186  */
187 int snd_device_register_all(struct snd_card *card)
188 {
189         struct snd_device *dev;
190         int err;
191         
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;
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         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;
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         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;
239                 }
240         }
241         return 0;
242 }