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 }
244
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