xref: /linux/sound/core/jack.c (revision 861e10be08c69808065d755d3e3cab5d520a2d32)
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 <linux/module.h>
25 #include <sound/jack.h>
26 #include <sound/core.h>
27 
28 static int jack_switch_types[SND_JACK_SWITCH_TYPES] = {
29 	SW_HEADPHONE_INSERT,
30 	SW_MICROPHONE_INSERT,
31 	SW_LINEOUT_INSERT,
32 	SW_JACK_PHYSICAL_INSERT,
33 	SW_VIDEOOUT_INSERT,
34 	SW_LINEIN_INSERT,
35 };
36 
37 static int snd_jack_dev_free(struct snd_device *device)
38 {
39 	struct snd_jack *jack = device->device_data;
40 
41 	if (jack->private_free)
42 		jack->private_free(jack);
43 
44 	/* If the input device is registered with the input subsystem
45 	 * then we need to use a different deallocator. */
46 	if (jack->registered)
47 		input_unregister_device(jack->input_dev);
48 	else
49 		input_free_device(jack->input_dev);
50 
51 	kfree(jack->id);
52 	kfree(jack);
53 
54 	return 0;
55 }
56 
57 static int snd_jack_dev_register(struct snd_device *device)
58 {
59 	struct snd_jack *jack = device->device_data;
60 	struct snd_card *card = device->card;
61 	int err, i;
62 
63 	snprintf(jack->name, sizeof(jack->name), "%s %s",
64 		 card->shortname, jack->id);
65 	jack->input_dev->name = jack->name;
66 
67 	/* Default to the sound card device. */
68 	if (!jack->input_dev->dev.parent)
69 		jack->input_dev->dev.parent = snd_card_get_device_link(card);
70 
71 	/* Add capabilities for any keys that are enabled */
72 	for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
73 		int testbit = SND_JACK_BTN_0 >> i;
74 
75 		if (!(jack->type & testbit))
76 			continue;
77 
78 		if (!jack->key[i])
79 			jack->key[i] = BTN_0 + i;
80 
81 		input_set_capability(jack->input_dev, EV_KEY, jack->key[i]);
82 	}
83 
84 	err = input_register_device(jack->input_dev);
85 	if (err == 0)
86 		jack->registered = 1;
87 
88 	return err;
89 }
90 
91 /**
92  * snd_jack_new - Create a new jack
93  * @card:  the card instance
94  * @id:    an identifying string for this jack
95  * @type:  a bitmask of enum snd_jack_type values that can be detected by
96  *         this jack
97  * @jjack: Used to provide the allocated jack object to the caller.
98  *
99  * Creates a new jack object.
100  *
101  * Returns zero if successful, or a negative error code on failure.
102  * On success jjack will be initialised.
103  */
104 int snd_jack_new(struct snd_card *card, const char *id, int type,
105 		 struct snd_jack **jjack)
106 {
107 	struct snd_jack *jack;
108 	int err;
109 	int i;
110 	static struct snd_device_ops ops = {
111 		.dev_free = snd_jack_dev_free,
112 		.dev_register = snd_jack_dev_register,
113 	};
114 
115 	jack = kzalloc(sizeof(struct snd_jack), GFP_KERNEL);
116 	if (jack == NULL)
117 		return -ENOMEM;
118 
119 	jack->id = kstrdup(id, GFP_KERNEL);
120 
121 	jack->input_dev = input_allocate_device();
122 	if (jack->input_dev == NULL) {
123 		err = -ENOMEM;
124 		goto fail_input;
125 	}
126 
127 	jack->input_dev->phys = "ALSA";
128 
129 	jack->type = type;
130 
131 	for (i = 0; i < SND_JACK_SWITCH_TYPES; i++)
132 		if (type & (1 << i))
133 			input_set_capability(jack->input_dev, EV_SW,
134 					     jack_switch_types[i]);
135 
136 	err = snd_device_new(card, SNDRV_DEV_JACK, jack, &ops);
137 	if (err < 0)
138 		goto fail_input;
139 
140 	*jjack = jack;
141 
142 	return 0;
143 
144 fail_input:
145 	input_free_device(jack->input_dev);
146 	kfree(jack->id);
147 	kfree(jack);
148 	return err;
149 }
150 EXPORT_SYMBOL(snd_jack_new);
151 
152 /**
153  * snd_jack_set_parent - Set the parent device for a jack
154  *
155  * @jack:   The jack to configure
156  * @parent: The device to set as parent for the jack.
157  *
158  * Set the parent for the jack devices in the device tree.  This
159  * function is only valid prior to registration of the jack.  If no
160  * parent is configured then the parent device will be the sound card.
161  */
162 void snd_jack_set_parent(struct snd_jack *jack, struct device *parent)
163 {
164 	WARN_ON(jack->registered);
165 
166 	jack->input_dev->dev.parent = parent;
167 }
168 EXPORT_SYMBOL(snd_jack_set_parent);
169 
170 /**
171  * snd_jack_set_key - Set a key mapping on a jack
172  *
173  * @jack:    The jack to configure
174  * @type:    Jack report type for this key
175  * @keytype: Input layer key type to be reported
176  *
177  * Map a SND_JACK_BTN_ button type to an input layer key, allowing
178  * reporting of keys on accessories via the jack abstraction.  If no
179  * mapping is provided but keys are enabled in the jack type then
180  * BTN_n numeric buttons will be reported.
181  *
182  * If jacks are not reporting via the input API this call will have no
183  * effect.
184  *
185  * Note that this is intended to be use by simple devices with small
186  * numbers of keys that can be reported.  It is also possible to
187  * access the input device directly - devices with complex input
188  * capabilities on accessories should consider doing this rather than
189  * using this abstraction.
190  *
191  * This function may only be called prior to registration of the jack.
192  */
193 int snd_jack_set_key(struct snd_jack *jack, enum snd_jack_types type,
194 		     int keytype)
195 {
196 	int key = fls(SND_JACK_BTN_0) - fls(type);
197 
198 	WARN_ON(jack->registered);
199 
200 	if (!keytype || key >= ARRAY_SIZE(jack->key))
201 		return -EINVAL;
202 
203 	jack->type |= type;
204 	jack->key[key] = keytype;
205 
206 	return 0;
207 }
208 EXPORT_SYMBOL(snd_jack_set_key);
209 
210 /**
211  * snd_jack_report - Report the current status of a jack
212  *
213  * @jack:   The jack to report status for
214  * @status: The current status of the jack
215  */
216 void snd_jack_report(struct snd_jack *jack, int status)
217 {
218 	int i;
219 
220 	if (!jack)
221 		return;
222 
223 	for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
224 		int testbit = SND_JACK_BTN_0 >> i;
225 
226 		if (jack->type & testbit)
227 			input_report_key(jack->input_dev, jack->key[i],
228 					 status & testbit);
229 	}
230 
231 	for (i = 0; i < ARRAY_SIZE(jack_switch_types); i++) {
232 		int testbit = 1 << i;
233 		if (jack->type & testbit)
234 			input_report_switch(jack->input_dev,
235 					    jack_switch_types[i],
236 					    status & testbit);
237 	}
238 
239 	input_sync(jack->input_dev);
240 }
241 EXPORT_SYMBOL(snd_jack_report);
242 
243 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
244 MODULE_DESCRIPTION("Jack detection support for ALSA");
245 MODULE_LICENSE("GPL");
246