linux/sound/core/jack.c
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   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
  28static 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
  37static 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
  57static 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 */
 104int 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
 144fail_input:
 145        input_free_device(jack->input_dev);
 146        kfree(jack->id);
 147        kfree(jack);
 148        return err;
 149}
 150EXPORT_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 */
 162void 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}
 168EXPORT_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 */
 193int 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}
 208EXPORT_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 */
 216void 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}
 241EXPORT_SYMBOL(snd_jack_report);
 242
 243MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 244MODULE_DESCRIPTION("Jack detection support for ALSA");
 245MODULE_LICENSE("GPL");
 246
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