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
  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");