xref: /openbmc/linux/sound/core/jack.c (revision 8ac727c1)
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 
27 static 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 
35 static 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 
55 static 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  */
102 int 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 
142 fail_input:
143 	input_free_device(jack->input_dev);
144 	kfree(jack->id);
145 	kfree(jack);
146 	return err;
147 }
148 EXPORT_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  */
160 void 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 }
166 EXPORT_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  */
188 int 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 }
203 EXPORT_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  */
211 void 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 }
236 EXPORT_SYMBOL(snd_jack_report);
237 
238 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
239 MODULE_DESCRIPTION("Jack detection support for ALSA");
240 MODULE_LICENSE("GPL");
241