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 <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");