sound/core/device.c

   1 /*
   2  *  Device management routines
   3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
   4  *
   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 <sound/driver.h>
  23 #include <linux/slab.h>
  24 #include <linux/time.h>
  25 #include <linux/errno.h>
  26 #include <sound/core.h>
  27
  28 /**
  29  * snd_device_new - create an ALSA device component
  30  * @card: the card instance
  31  * @type: the device type, SNDRV_DEV_XXX
  32  * @device_data: the data pointer of this device
  33  * @ops: the operator table
  34  *
  35  * Creates a new device component for the given data pointer.
  36  * The device will be assigned to the card and managed together
  37  * by the card.
  38  *
  39  * The data pointer plays a role as the identifier, too, so the
  40  * pointer address must be unique and unchanged.
  41  *
  42  * Returns zero if successful, or a negative error code on failure.
  43  */
  44 int snd_device_new(snd_card_t *card, snd_device_type_t type,
  45                    void *device_data, snd_device_ops_t *ops)
  46 {
  47         snd_device_t *dev;
  48
  49         snd_assert(card != NULL, return -ENXIO);
  50         snd_assert(device_data != NULL, return -ENXIO);
  51         snd_assert(ops != NULL, return -ENXIO);
  52         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
  53         if (dev == NULL)
  54                 return -ENOMEM;
  55         dev->card = card;
  56         dev->type = type;
  57         dev->state = SNDRV_DEV_BUILD;
  58         dev->device_data = device_data;
  59         dev->ops = ops;
  60         list_add(&dev->list, &card->devices);   /* add to the head of list */
  61         return 0;
  62 }
  63
  64 /**
  65  * snd_device_free - release the device from the card
  66  * @card: the card instance
  67  * @device_data: the data pointer to release
  68  *
  69  * Removes the device from the list on the card and invokes the
  70  * callback, dev_unregister or dev_free, corresponding to the state.
  71  * Then release the device.
  72  *
  73  * Returns zero if successful, or a negative error code on failure or if the
  74  * device not found.
  75  */
  76 int snd_device_free(snd_card_t *card, void *device_data)
  77 {
  78         struct list_head *list;
  79         snd_device_t *dev;
  80
  81         snd_assert(card != NULL, return -ENXIO);
  82         snd_assert(device_data != NULL, return -ENXIO);
  83         list_for_each(list, &card->devices) {
  84                 dev = snd_device(list);
  85                 if (dev->device_data != device_data)
  86                         continue;
  87                 /* unlink */
  88                 list_del(&dev->list);
  89                 if ((dev->state == SNDRV_DEV_REGISTERED || dev->state == SNDRV_DEV_DISCONNECTED) &&
  90                     dev->ops->dev_unregister) {
  91                         if (dev->ops->dev_unregister(dev))
  92                                 snd_printk(KERN_ERR "device unregister failure\n");
  93                 } else {
  94                         if (dev->ops->dev_free) {
  95                                 if (dev->ops->dev_free(dev))
  96                                         snd_printk(KERN_ERR "device free failure\n");
  97                         }
  98                 }
  99                 kfree(dev);
 100                 return 0;
 101         }
 102         snd_printd("device free %p (from %p), not found\n", device_data, __builtin_return_address(0));
 103         return -ENXIO;
 104 }
 105
 106 /**
 107  * snd_device_disconnect - disconnect the device
 108  * @card: the card instance
 109  * @device_data: the data pointer to disconnect
 110  *
 111  * Turns the device into the disconnection state, invoking
 112  * dev_disconnect callback, if the device was already registered.
 113  *
 114  * Usually called from snd_card_disconnect().
 115  *
 116  * Returns zero if successful, or a negative error code on failure or if the
 117  * device not found.
 118  */
 119 int snd_device_disconnect(snd_card_t *card, void *device_data)
 120 {
 121         struct list_head *list;
 122         snd_device_t *dev;
 123
 124         snd_assert(card != NULL, return -ENXIO);
 125         snd_assert(device_data != NULL, return -ENXIO);
 126         list_for_each(list, &card->devices) {
 127                 dev = snd_device(list);
 128                 if (dev->device_data != device_data)
 129                         continue;
 130                 if (dev->state == SNDRV_DEV_REGISTERED && dev->ops->dev_disconnect) {
 131                         if (dev->ops->dev_disconnect(dev))
 132                                 snd_printk(KERN_ERR "device disconnect failure\n");
 133                         dev->state = SNDRV_DEV_DISCONNECTED;
 134                 }
 135                 return 0;
 136         }
 137         snd_printd("device disconnect %p (from %p), not found\n", device_data, __builtin_return_address(0));
 138         return -ENXIO;
 139 }
 140
 141 /**
 142  * snd_device_register - register the device
 143  * @card: the card instance
 144  * @device_data: the data pointer to register
 145  *
 146  * Registers the device which was already created via
 147  * snd_device_new().  Usually this is called from snd_card_register(),
 148  * but it can be called later if any new devices are created after
 149  * invocation of snd_card_register().
 150  *
 151  * Returns zero if successful, or a negative error code on failure or if the
 152  * device not found.
 153  */
 154 int snd_device_register(snd_card_t *card, void *device_data)
 155 {
 156         struct list_head *list;
 157         snd_device_t *dev;
 158         int err;
 159
 160         snd_assert(card != NULL, return -ENXIO);
 161         snd_assert(device_data != NULL, return -ENXIO);
 162         list_for_each(list, &card->devices) {
 163                 dev = snd_device(list);
 164                 if (dev->device_data != device_data)
 165                         continue;
 166                 if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
 167                         if ((err = dev->ops->dev_register(dev)) < 0)
 168                                 return err;
 169                         dev->state = SNDRV_DEV_REGISTERED;
 170                         return 0;
 171                 }
 172                 return -EBUSY;
 173         }
 174         snd_BUG();
 175         return -ENXIO;
 176 }
 177
 178 /*
 179  * register all the devices on the card.
 180  * called from init.c
 181  */
 182 int snd_device_register_all(snd_card_t *card)
 183 {
 184         struct list_head *list;
 185         snd_device_t *dev;
 186         int err;
 187
 188         snd_assert(card != NULL, return -ENXIO);
 189         list_for_each(list, &card->devices) {
 190                 dev = snd_device(list);
 191                 if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
 192                         if ((err = dev->ops->dev_register(dev)) < 0)
 193                                 return err;
 194                         dev->state = SNDRV_DEV_REGISTERED;
 195                 }
 196         }
 197         return 0;
 198 }
 199
 200 /*
 201  * disconnect all the devices on the card.
 202  * called from init.c
 203  */
 204 int snd_device_disconnect_all(snd_card_t *card)
 205 {
 206         snd_device_t *dev;
 207         struct list_head *list;
 208         int err = 0;
 209
 210         snd_assert(card != NULL, return -ENXIO);
 211         list_for_each(list, &card->devices) {
 212                 dev = snd_device(list);
 213                 if (snd_device_disconnect(card, dev->device_data) < 0)
 214                         err = -ENXIO;
 215         }
 216         return err;
 217 }
 218
 219 /*
 220  * release all the devices on the card.
 221  * called from init.c
 222  */
 223 int snd_device_free_all(snd_card_t *card, snd_device_cmd_t cmd)
 224 {
 225         snd_device_t *dev;
 226         struct list_head *list;
 227         int err;
 228         unsigned int range_low, range_high;
 229
 230         snd_assert(card != NULL, return -ENXIO);
 231         range_low = cmd * SNDRV_DEV_TYPE_RANGE_SIZE;
 232         range_high = range_low + SNDRV_DEV_TYPE_RANGE_SIZE - 1;
 233       __again:
 234         list_for_each(list, &card->devices) {
 235                 dev = snd_device(list);
 236                 if (dev->type >= range_low && dev->type <= range_high) {
 237                         if ((err = snd_device_free(card, dev->device_data)) < 0)
 238                                 return err;
 239                         goto __again;
 240                 }
 241         }
 242         return 0;
 243 }