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