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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 | * Return: Zero if successful, or a negative error code on failure. | |
43 | */ | |
44 | int snd_device_new(struct snd_card *card, enum snd_device_type type, | |
45 | void *device_data, struct snd_device_ops *ops) | |
46 | { | |
47 | struct snd_device *dev; | |
48 | struct list_head *p; | |
49 | ||
50 | if (snd_BUG_ON(!card || !device_data || !ops)) | |
51 | return -ENXIO; | |
52 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); | |
53 | if (dev == NULL) { | |
54 | dev_err(card->dev, "Cannot allocate device, type=%d\n", type); | |
55 | return -ENOMEM; | |
56 | } | |
57 | INIT_LIST_HEAD(&dev->list); | |
58 | dev->card = card; | |
59 | dev->type = type; | |
60 | dev->state = SNDRV_DEV_BUILD; | |
61 | dev->device_data = device_data; | |
62 | dev->ops = ops; | |
63 | ||
64 | /* insert the entry in an incrementally sorted list */ | |
65 | list_for_each_prev(p, &card->devices) { | |
66 | struct snd_device *pdev = list_entry(p, struct snd_device, list); | |
67 | if ((unsigned int)pdev->type <= (unsigned int)type) | |
68 | break; | |
69 | } | |
70 | ||
71 | list_add(&dev->list, p); | |
72 | return 0; | |
73 | } | |
74 | EXPORT_SYMBOL(snd_device_new); | |
75 | ||
76 | static int __snd_device_disconnect(struct snd_device *dev) | |
77 | { | |
78 | if (dev->state == SNDRV_DEV_REGISTERED) { | |
79 | if (dev->ops->dev_disconnect && | |
80 | dev->ops->dev_disconnect(dev)) | |
81 | dev_err(dev->card->dev, "device disconnect failure\n"); | |
82 | dev->state = SNDRV_DEV_DISCONNECTED; | |
83 | } | |
84 | return 0; | |
85 | } | |
86 | ||
87 | static void __snd_device_free(struct snd_device *dev) | |
88 | { | |
89 | /* unlink */ | |
90 | list_del(&dev->list); | |
91 | ||
92 | __snd_device_disconnect(dev); | |
93 | if (dev->ops->dev_free) { | |
94 | if (dev->ops->dev_free(dev)) | |
95 | dev_err(dev->card->dev, "device free failure\n"); | |
96 | } | |
97 | kfree(dev); | |
98 | } | |
99 | ||
100 | static struct snd_device *look_for_dev(struct snd_card *card, void *device_data) | |
101 | { | |
102 | struct snd_device *dev; | |
103 | ||
104 | list_for_each_entry(dev, &card->devices, list) | |
105 | if (dev->device_data == device_data) | |
106 | return dev; | |
107 | ||
108 | return NULL; | |
109 | } | |
110 | ||
111 | /** | |
112 | * snd_device_free - release the device from the card | |
113 | * @card: the card instance | |
114 | * @device_data: the data pointer to release | |
115 | * | |
116 | * Removes the device from the list on the card and invokes the | |
117 | * callbacks, dev_disconnect and dev_free, corresponding to the state. | |
118 | * Then release the device. | |
119 | */ | |
120 | void snd_device_free(struct snd_card *card, void *device_data) | |
121 | { | |
122 | struct snd_device *dev; | |
123 | ||
124 | if (snd_BUG_ON(!card || !device_data)) | |
125 | return; | |
126 | dev = look_for_dev(card, device_data); | |
127 | if (dev) | |
128 | __snd_device_free(dev); | |
129 | else | |
130 | dev_dbg(card->dev, "device free %p (from %pF), not found\n", | |
131 | device_data, __builtin_return_address(0)); | |
132 | } | |
133 | EXPORT_SYMBOL(snd_device_free); | |
134 | ||
135 | static int __snd_device_register(struct snd_device *dev) | |
136 | { | |
137 | if (dev->state == SNDRV_DEV_BUILD) { | |
138 | if (dev->ops->dev_register) { | |
139 | int err = dev->ops->dev_register(dev); | |
140 | if (err < 0) | |
141 | return err; | |
142 | } | |
143 | dev->state = SNDRV_DEV_REGISTERED; | |
144 | } | |
145 | return 0; | |
146 | } | |
147 | ||
148 | /** | |
149 | * snd_device_register - register the device | |
150 | * @card: the card instance | |
151 | * @device_data: the data pointer to register | |
152 | * | |
153 | * Registers the device which was already created via | |
154 | * snd_device_new(). Usually this is called from snd_card_register(), | |
155 | * but it can be called later if any new devices are created after | |
156 | * invocation of snd_card_register(). | |
157 | * | |
158 | * Return: Zero if successful, or a negative error code on failure or if the | |
159 | * device not found. | |
160 | */ | |
161 | int snd_device_register(struct snd_card *card, void *device_data) | |
162 | { | |
163 | struct snd_device *dev; | |
164 | ||
165 | if (snd_BUG_ON(!card || !device_data)) | |
166 | return -ENXIO; | |
167 | dev = look_for_dev(card, device_data); | |
168 | if (dev) | |
169 | return __snd_device_register(dev); | |
170 | snd_BUG(); | |
171 | return -ENXIO; | |
172 | } | |
173 | EXPORT_SYMBOL(snd_device_register); | |
174 | ||
175 | /* | |
176 | * register all the devices on the card. | |
177 | * called from init.c | |
178 | */ | |
179 | int snd_device_register_all(struct snd_card *card) | |
180 | { | |
181 | struct snd_device *dev; | |
182 | int err; | |
183 | ||
184 | if (snd_BUG_ON(!card)) | |
185 | return -ENXIO; | |
186 | list_for_each_entry(dev, &card->devices, list) { | |
187 | err = __snd_device_register(dev); | |
188 | if (err < 0) | |
189 | return err; | |
190 | } | |
191 | return 0; | |
192 | } | |
193 | ||
194 | /* | |
195 | * disconnect all the devices on the card. | |
196 | * called from init.c | |
197 | */ | |
198 | int snd_device_disconnect_all(struct snd_card *card) | |
199 | { | |
200 | struct snd_device *dev; | |
201 | int err = 0; | |
202 | ||
203 | if (snd_BUG_ON(!card)) | |
204 | return -ENXIO; | |
205 | list_for_each_entry_reverse(dev, &card->devices, list) { | |
206 | if (__snd_device_disconnect(dev) < 0) | |
207 | err = -ENXIO; | |
208 | } | |
209 | return err; | |
210 | } | |
211 | ||
212 | /* | |
213 | * release all the devices on the card. | |
214 | * called from init.c | |
215 | */ | |
216 | void snd_device_free_all(struct snd_card *card) | |
217 | { | |
218 | struct snd_device *dev, *next; | |
219 | ||
220 | if (snd_BUG_ON(!card)) | |
221 | return; | |
222 | list_for_each_entry_safe_reverse(dev, next, &card->devices, list) | |
223 | __snd_device_free(dev); | |
224 | } |