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 */
44int 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)
54		return -ENOMEM;
55	INIT_LIST_HEAD(&dev->list);
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
62	/* insert the entry in an incrementally sorted list */
63	list_for_each_prev(p, &card->devices) {
64		struct snd_device *pdev = list_entry(p, struct snd_device, list);
65		if ((unsigned int)pdev->type <= (unsigned int)type)
66			break;
67	}
68
69	list_add(&dev->list, p);
70	return 0;
71}
72EXPORT_SYMBOL(snd_device_new);
73
74static void __snd_device_disconnect(struct snd_device *dev)
75{
76	if (dev->state == SNDRV_DEV_REGISTERED) {
77		if (dev->ops->dev_disconnect &&
78		    dev->ops->dev_disconnect(dev))
79			dev_err(dev->card->dev, "device disconnect failure\n");
80		dev->state = SNDRV_DEV_DISCONNECTED;
81	}
82}
83
84static void __snd_device_free(struct snd_device *dev)
85{
86	/* unlink */
87	list_del(&dev->list);
88
89	__snd_device_disconnect(dev);
90	if (dev->ops->dev_free) {
91		if (dev->ops->dev_free(dev))
92			dev_err(dev->card->dev, "device free failure\n");
93	}
94	kfree(dev);
95}
96
97static struct snd_device *look_for_dev(struct snd_card *card, void *device_data)
98{
99	struct snd_device *dev;
100
101	list_for_each_entry(dev, &card->devices, list)
102		if (dev->device_data == device_data)
103			return dev;
104
105	return NULL;
106}
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 * Return: Zero if successful, or a negative error code on failure or if the
119 * device not found.
120 */
121void 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;
127	dev = look_for_dev(card, device_data);
128	if (dev)
129		__snd_device_disconnect(dev);
130	else
131		dev_dbg(card->dev, "device disconnect %p (from %pF), not found\n",
132			device_data, __builtin_return_address(0));
133}
134EXPORT_SYMBOL_GPL(snd_device_disconnect);
135
136/**
137 * snd_device_free - release the device from the card
138 * @card: the card instance
139 * @device_data: the data pointer to release
140 *
141 * Removes the device from the list on the card and invokes the
142 * callbacks, dev_disconnect and dev_free, corresponding to the state.
143 * Then release the device.
144 */
145void snd_device_free(struct snd_card *card, void *device_data)
146{
147	struct snd_device *dev;
148
149	if (snd_BUG_ON(!card || !device_data))
150		return;
151	dev = look_for_dev(card, device_data);
152	if (dev)
153		__snd_device_free(dev);
154	else
155		dev_dbg(card->dev, "device free %p (from %pF), not found\n",
156			device_data, __builtin_return_address(0));
157}
158EXPORT_SYMBOL(snd_device_free);
159
160static int __snd_device_register(struct snd_device *dev)
161{
162	if (dev->state == SNDRV_DEV_BUILD) {
163		if (dev->ops->dev_register) {
164			int err = dev->ops->dev_register(dev);
165			if (err < 0)
166				return err;
167		}
168		dev->state = SNDRV_DEV_REGISTERED;
169	}
170	return 0;
171}
172
173/**
174 * snd_device_register - register the device
175 * @card: the card instance
176 * @device_data: the data pointer to register
177 *
178 * Registers the device which was already created via
179 * snd_device_new().  Usually this is called from snd_card_register(),
180 * but it can be called later if any new devices are created after
181 * invocation of snd_card_register().
182 *
183 * Return: Zero if successful, or a negative error code on failure or if the
184 * device not found.
185 */
186int snd_device_register(struct snd_card *card, void *device_data)
187{
188	struct snd_device *dev;
189
190	if (snd_BUG_ON(!card || !device_data))
191		return -ENXIO;
192	dev = look_for_dev(card, device_data);
193	if (dev)
194		return __snd_device_register(dev);
195	snd_BUG();
196	return -ENXIO;
197}
198EXPORT_SYMBOL(snd_device_register);
199
200/*
201 * register all the devices on the card.
202 * called from init.c
203 */
204int snd_device_register_all(struct snd_card *card)
205{
206	struct snd_device *dev;
207	int err;
208
209	if (snd_BUG_ON(!card))
210		return -ENXIO;
211	list_for_each_entry(dev, &card->devices, list) {
212		err = __snd_device_register(dev);
213		if (err < 0)
214			return err;
215	}
216	return 0;
217}
218
219/*
220 * disconnect all the devices on the card.
221 * called from init.c
222 */
223void snd_device_disconnect_all(struct snd_card *card)
224{
225	struct snd_device *dev;
226
227	if (snd_BUG_ON(!card))
228		return;
229	list_for_each_entry_reverse(dev, &card->devices, list)
230		__snd_device_disconnect(dev);
231}
232
233/*
234 * release all the devices on the card.
235 * called from init.c
236 */
237void snd_device_free_all(struct snd_card *card)
238{
239	struct snd_device *dev, *next;
240
241	if (snd_BUG_ON(!card))
242		return;
243	list_for_each_entry_safe_reverse(dev, next, &card->devices, list)
244		__snd_device_free(dev);
245}
246