xref: /openbmc/linux/sound/core/jack.c (revision 8e9356c6)
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_disconnect(struct snd_device *device)
38 {
39 	struct snd_jack *jack = device->device_data;
40 
41 	if (!jack->input_dev)
42 		return 0;
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 	jack->input_dev = NULL;
51 	return 0;
52 }
53 
54 static int snd_jack_dev_free(struct snd_device *device)
55 {
56 	struct snd_jack *jack = device->device_data;
57 
58 	if (jack->private_free)
59 		jack->private_free(jack);
60 
61 	snd_jack_dev_disconnect(device);
62 
63 	kfree(jack->id);
64 	kfree(jack);
65 
66 	return 0;
67 }
68 
69 static int snd_jack_dev_register(struct snd_device *device)
70 {
71 	struct snd_jack *jack = device->device_data;
72 	struct snd_card *card = device->card;
73 	int err, i;
74 
75 	snprintf(jack->name, sizeof(jack->name), "%s %s",
76 		 card->shortname, jack->id);
77 	jack->input_dev->name = jack->name;
78 
79 	/* Default to the sound card device. */
80 	if (!jack->input_dev->dev.parent)
81 		jack->input_dev->dev.parent = snd_card_get_device_link(card);
82 
83 	/* Add capabilities for any keys that are enabled */
84 	for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
85 		int testbit = SND_JACK_BTN_0 >> i;
86 
87 		if (!(jack->type & testbit))
88 			continue;
89 
90 		if (!jack->key[i])
91 			jack->key[i] = BTN_0 + i;
92 
93 		input_set_capability(jack->input_dev, EV_KEY, jack->key[i]);
94 	}
95 
96 	err = input_register_device(jack->input_dev);
97 	if (err == 0)
98 		jack->registered = 1;
99 
100 	return err;
101 }
102 
103 /**
104  * snd_jack_new - Create a new jack
105  * @card:  the card instance
106  * @id:    an identifying string for this jack
107  * @type:  a bitmask of enum snd_jack_type values that can be detected by
108  *         this jack
109  * @jjack: Used to provide the allocated jack object to the caller.
110  *
111  * Creates a new jack object.
112  *
113  * Return: Zero if successful, or a negative error code on failure.
114  * On success @jjack will be initialised.
115  */
116 int snd_jack_new(struct snd_card *card, const char *id, int type,
117 		 struct snd_jack **jjack)
118 {
119 	struct snd_jack *jack;
120 	int err;
121 	int i;
122 	static struct snd_device_ops ops = {
123 		.dev_free = snd_jack_dev_free,
124 		.dev_register = snd_jack_dev_register,
125 		.dev_disconnect = snd_jack_dev_disconnect,
126 	};
127 
128 	jack = kzalloc(sizeof(struct snd_jack), GFP_KERNEL);
129 	if (jack == NULL)
130 		return -ENOMEM;
131 
132 	jack->id = kstrdup(id, GFP_KERNEL);
133 
134 	jack->input_dev = input_allocate_device();
135 	if (jack->input_dev == NULL) {
136 		err = -ENOMEM;
137 		goto fail_input;
138 	}
139 
140 	jack->input_dev->phys = "ALSA";
141 
142 	jack->type = type;
143 
144 	for (i = 0; i < SND_JACK_SWITCH_TYPES; i++)
145 		if (type & (1 << i))
146 			input_set_capability(jack->input_dev, EV_SW,
147 					     jack_switch_types[i]);
148 
149 	err = snd_device_new(card, SNDRV_DEV_JACK, jack, &ops);
150 	if (err < 0)
151 		goto fail_input;
152 
153 	*jjack = jack;
154 
155 	return 0;
156 
157 fail_input:
158 	input_free_device(jack->input_dev);
159 	kfree(jack->id);
160 	kfree(jack);
161 	return err;
162 }
163 EXPORT_SYMBOL(snd_jack_new);
164 
165 /**
166  * snd_jack_set_parent - Set the parent device for a jack
167  *
168  * @jack:   The jack to configure
169  * @parent: The device to set as parent for the jack.
170  *
171  * Set the parent for the jack devices in the device tree.  This
172  * function is only valid prior to registration of the jack.  If no
173  * parent is configured then the parent device will be the sound card.
174  */
175 void snd_jack_set_parent(struct snd_jack *jack, struct device *parent)
176 {
177 	WARN_ON(jack->registered);
178 
179 	jack->input_dev->dev.parent = parent;
180 }
181 EXPORT_SYMBOL(snd_jack_set_parent);
182 
183 /**
184  * snd_jack_set_key - Set a key mapping on a jack
185  *
186  * @jack:    The jack to configure
187  * @type:    Jack report type for this key
188  * @keytype: Input layer key type to be reported
189  *
190  * Map a SND_JACK_BTN_ button type to an input layer key, allowing
191  * reporting of keys on accessories via the jack abstraction.  If no
192  * mapping is provided but keys are enabled in the jack type then
193  * BTN_n numeric buttons will be reported.
194  *
195  * If jacks are not reporting via the input API this call will have no
196  * effect.
197  *
198  * Note that this is intended to be use by simple devices with small
199  * numbers of keys that can be reported.  It is also possible to
200  * access the input device directly - devices with complex input
201  * capabilities on accessories should consider doing this rather than
202  * using this abstraction.
203  *
204  * This function may only be called prior to registration of the jack.
205  *
206  * Return: Zero if successful, or a negative error code on failure.
207  */
208 int snd_jack_set_key(struct snd_jack *jack, enum snd_jack_types type,
209 		     int keytype)
210 {
211 	int key = fls(SND_JACK_BTN_0) - fls(type);
212 
213 	WARN_ON(jack->registered);
214 
215 	if (!keytype || key >= ARRAY_SIZE(jack->key))
216 		return -EINVAL;
217 
218 	jack->type |= type;
219 	jack->key[key] = keytype;
220 
221 	return 0;
222 }
223 EXPORT_SYMBOL(snd_jack_set_key);
224 
225 /**
226  * snd_jack_report - Report the current status of a jack
227  *
228  * @jack:   The jack to report status for
229  * @status: The current status of the jack
230  */
231 void snd_jack_report(struct snd_jack *jack, int status)
232 {
233 	int i;
234 
235 	if (!jack)
236 		return;
237 
238 	for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
239 		int testbit = SND_JACK_BTN_0 >> i;
240 
241 		if (jack->type & testbit)
242 			input_report_key(jack->input_dev, jack->key[i],
243 					 status & testbit);
244 	}
245 
246 	for (i = 0; i < ARRAY_SIZE(jack_switch_types); i++) {
247 		int testbit = 1 << i;
248 		if (jack->type & testbit)
249 			input_report_switch(jack->input_dev,
250 					    jack_switch_types[i],
251 					    status & testbit);
252 	}
253 
254 	input_sync(jack->input_dev);
255 }
256 EXPORT_SYMBOL(snd_jack_report);
257 
258 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
259 MODULE_DESCRIPTION("Jack detection support for ALSA");
260 MODULE_LICENSE("GPL");
261