Root/sound/core/jack.c

1/*
2 * Jack abstraction layer
3 *
4 * Copyright 2008 Wolfson Microelectronics
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/input.h>
23#include <linux/slab.h>
24#include <sound/jack.h>
25#include <sound/core.h>
26
27static int jack_switch_types[] = {
28    SW_HEADPHONE_INSERT,
29    SW_MICROPHONE_INSERT,
30    SW_LINEOUT_INSERT,
31    SW_JACK_PHYSICAL_INSERT,
32    SW_VIDEOOUT_INSERT,
33};
34
35static int snd_jack_dev_free(struct snd_device *device)
36{
37    struct snd_jack *jack = device->device_data;
38
39    if (jack->private_free)
40        jack->private_free(jack);
41
42    /* If the input device is registered with the input subsystem
43     * then we need to use a different deallocator. */
44    if (jack->registered)
45        input_unregister_device(jack->input_dev);
46    else
47        input_free_device(jack->input_dev);
48
49    kfree(jack->id);
50    kfree(jack);
51
52    return 0;
53}
54
55static int snd_jack_dev_register(struct snd_device *device)
56{
57    struct snd_jack *jack = device->device_data;
58    struct snd_card *card = device->card;
59    int err, i;
60
61    snprintf(jack->name, sizeof(jack->name), "%s %s",
62         card->shortname, jack->id);
63    jack->input_dev->name = jack->name;
64
65    /* Default to the sound card device. */
66    if (!jack->input_dev->dev.parent)
67        jack->input_dev->dev.parent = snd_card_get_device_link(card);
68
69    /* Add capabilities for any keys that are enabled */
70    for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
71        int testbit = SND_JACK_BTN_0 >> i;
72
73        if (!(jack->type & testbit))
74            continue;
75
76        if (!jack->key[i])
77            jack->key[i] = BTN_0 + i;
78
79        input_set_capability(jack->input_dev, EV_KEY, jack->key[i]);
80    }
81
82    err = input_register_device(jack->input_dev);
83    if (err == 0)
84        jack->registered = 1;
85
86    return err;
87}
88
89/**
90 * snd_jack_new - Create a new jack
91 * @card: the card instance
92 * @id: an identifying string for this jack
93 * @type: a bitmask of enum snd_jack_type values that can be detected by
94 * this jack
95 * @jjack: Used to provide the allocated jack object to the caller.
96 *
97 * Creates a new jack object.
98 *
99 * Returns zero if successful, or a negative error code on failure.
100 * On success jjack will be initialised.
101 */
102int snd_jack_new(struct snd_card *card, const char *id, int type,
103         struct snd_jack **jjack)
104{
105    struct snd_jack *jack;
106    int err;
107    int i;
108    static struct snd_device_ops ops = {
109        .dev_free = snd_jack_dev_free,
110        .dev_register = snd_jack_dev_register,
111    };
112
113    jack = kzalloc(sizeof(struct snd_jack), GFP_KERNEL);
114    if (jack == NULL)
115        return -ENOMEM;
116
117    jack->id = kstrdup(id, GFP_KERNEL);
118
119    jack->input_dev = input_allocate_device();
120    if (jack->input_dev == NULL) {
121        err = -ENOMEM;
122        goto fail_input;
123    }
124
125    jack->input_dev->phys = "ALSA";
126
127    jack->type = type;
128
129    for (i = 0; i < ARRAY_SIZE(jack_switch_types); i++)
130        if (type & (1 << i))
131            input_set_capability(jack->input_dev, EV_SW,
132                         jack_switch_types[i]);
133
134    err = snd_device_new(card, SNDRV_DEV_JACK, jack, &ops);
135    if (err < 0)
136        goto fail_input;
137
138    *jjack = jack;
139
140    return 0;
141
142fail_input:
143    input_free_device(jack->input_dev);
144    kfree(jack->id);
145    kfree(jack);
146    return err;
147}
148EXPORT_SYMBOL(snd_jack_new);
149
150/**
151 * snd_jack_set_parent - Set the parent device for a jack
152 *
153 * @jack: The jack to configure
154 * @parent: The device to set as parent for the jack.
155 *
156 * Set the parent for the jack input device in the device tree. This
157 * function is only valid prior to registration of the jack. If no
158 * parent is configured then the parent device will be the sound card.
159 */
160void snd_jack_set_parent(struct snd_jack *jack, struct device *parent)
161{
162    WARN_ON(jack->registered);
163
164    jack->input_dev->dev.parent = parent;
165}
166EXPORT_SYMBOL(snd_jack_set_parent);
167
168/**
169 * snd_jack_set_key - Set a key mapping on a jack
170 *
171 * @jack: The jack to configure
172 * @type: Jack report type for this key
173 * @keytype: Input layer key type to be reported
174 *
175 * Map a SND_JACK_BTN_ button type to an input layer key, allowing
176 * reporting of keys on accessories via the jack abstraction. If no
177 * mapping is provided but keys are enabled in the jack type then
178 * BTN_n numeric buttons will be reported.
179 *
180 * Note that this is intended to be use by simple devices with small
181 * numbers of keys that can be reported. It is also possible to
182 * access the input device directly - devices with complex input
183 * capabilities on accessories should consider doing this rather than
184 * using this abstraction.
185 *
186 * This function may only be called prior to registration of the jack.
187 */
188int snd_jack_set_key(struct snd_jack *jack, enum snd_jack_types type,
189             int keytype)
190{
191    int key = fls(SND_JACK_BTN_0) - fls(type);
192
193    WARN_ON(jack->registered);
194
195    if (!keytype || key >= ARRAY_SIZE(jack->key))
196        return -EINVAL;
197
198    jack->type |= type;
199    jack->key[key] = keytype;
200
201    return 0;
202}
203EXPORT_SYMBOL(snd_jack_set_key);
204
205/**
206 * snd_jack_report - Report the current status of a jack
207 *
208 * @jack: The jack to report status for
209 * @status: The current status of the jack
210 */
211void snd_jack_report(struct snd_jack *jack, int status)
212{
213    int i;
214
215    if (!jack)
216        return;
217
218    for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
219        int testbit = SND_JACK_BTN_0 >> i;
220
221        if (jack->type & testbit)
222            input_report_key(jack->input_dev, jack->key[i],
223                     status & testbit);
224    }
225
226    for (i = 0; i < ARRAY_SIZE(jack_switch_types); i++) {
227        int testbit = 1 << i;
228        if (jack->type & testbit)
229            input_report_switch(jack->input_dev,
230                        jack_switch_types[i],
231                        status & testbit);
232    }
233
234    input_sync(jack->input_dev);
235}
236EXPORT_SYMBOL(snd_jack_report);
237
238MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
239MODULE_DESCRIPTION("Jack detection support for ALSA");
240MODULE_LICENSE("GPL");
241

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