| 1 | /* |
| 2 | * Device management routines |
| 3 | * Copyright (c) by Jaroslav Kysela <perex@perex.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 <linux/slab.h> |
| 23 | #include <linux/time.h> |
| 24 | #include <linux/export.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 | * Return: Zero if successful, or a negative error code on failure. |
| 43 | */ |
| 44 | int snd_device_new(struct snd_card *card, enum snd_device_type type, |
| 45 | void *device_data, struct snd_device_ops *ops) |
| 46 | { |
| 47 | struct snd_device *dev; |
| 48 | struct list_head *p; |
| 49 | |
| 50 | if (snd_BUG_ON(!card || !device_data || !ops)) |
| 51 | return -ENXIO; |
| 52 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
| 53 | if (!dev) |
| 54 | return -ENOMEM; |
| 55 | INIT_LIST_HEAD(&dev->list); |
| 56 | dev->card = card; |
| 57 | dev->type = type; |
| 58 | dev->state = SNDRV_DEV_BUILD; |
| 59 | dev->device_data = device_data; |
| 60 | dev->ops = ops; |
| 61 | |
| 62 | /* insert the entry in an incrementally sorted list */ |
| 63 | list_for_each_prev(p, &card->devices) { |
| 64 | struct snd_device *pdev = list_entry(p, struct snd_device, list); |
| 65 | if ((unsigned int)pdev->type <= (unsigned int)type) |
| 66 | break; |
| 67 | } |
| 68 | |
| 69 | list_add(&dev->list, p); |
| 70 | return 0; |
| 71 | } |
| 72 | EXPORT_SYMBOL(snd_device_new); |
| 73 | |
| 74 | static void __snd_device_disconnect(struct snd_device *dev) |
| 75 | { |
| 76 | if (dev->state == SNDRV_DEV_REGISTERED) { |
| 77 | if (dev->ops->dev_disconnect && |
| 78 | dev->ops->dev_disconnect(dev)) |
| 79 | dev_err(dev->card->dev, "device disconnect failure\n"); |
| 80 | dev->state = SNDRV_DEV_DISCONNECTED; |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | static void __snd_device_free(struct snd_device *dev) |
| 85 | { |
| 86 | /* unlink */ |
| 87 | list_del(&dev->list); |
| 88 | |
| 89 | __snd_device_disconnect(dev); |
| 90 | if (dev->ops->dev_free) { |
| 91 | if (dev->ops->dev_free(dev)) |
| 92 | dev_err(dev->card->dev, "device free failure\n"); |
| 93 | } |
| 94 | kfree(dev); |
| 95 | } |
| 96 | |
| 97 | static struct snd_device *look_for_dev(struct snd_card *card, void *device_data) |
| 98 | { |
| 99 | struct snd_device *dev; |
| 100 | |
| 101 | list_for_each_entry(dev, &card->devices, list) |
| 102 | if (dev->device_data == device_data) |
| 103 | return dev; |
| 104 | |
| 105 | return NULL; |
| 106 | } |
| 107 | |
| 108 | /** |
| 109 | * snd_device_disconnect - disconnect the device |
| 110 | * @card: the card instance |
| 111 | * @device_data: the data pointer to disconnect |
| 112 | * |
| 113 | * Turns the device into the disconnection state, invoking |
| 114 | * dev_disconnect callback, if the device was already registered. |
| 115 | * |
| 116 | * Usually called from snd_card_disconnect(). |
| 117 | * |
| 118 | * Return: Zero if successful, or a negative error code on failure or if the |
| 119 | * device not found. |
| 120 | */ |
| 121 | void snd_device_disconnect(struct snd_card *card, void *device_data) |
| 122 | { |
| 123 | struct snd_device *dev; |
| 124 | |
| 125 | if (snd_BUG_ON(!card || !device_data)) |
| 126 | return; |
| 127 | dev = look_for_dev(card, device_data); |
| 128 | if (dev) |
| 129 | __snd_device_disconnect(dev); |
| 130 | else |
| 131 | dev_dbg(card->dev, "device disconnect %p (from %pF), not found\n", |
| 132 | device_data, __builtin_return_address(0)); |
| 133 | } |
| 134 | EXPORT_SYMBOL_GPL(snd_device_disconnect); |
| 135 | |
| 136 | /** |
| 137 | * snd_device_free - release the device from the card |
| 138 | * @card: the card instance |
| 139 | * @device_data: the data pointer to release |
| 140 | * |
| 141 | * Removes the device from the list on the card and invokes the |
| 142 | * callbacks, dev_disconnect and dev_free, corresponding to the state. |
| 143 | * Then release the device. |
| 144 | */ |
| 145 | void snd_device_free(struct snd_card *card, void *device_data) |
| 146 | { |
| 147 | struct snd_device *dev; |
| 148 | |
| 149 | if (snd_BUG_ON(!card || !device_data)) |
| 150 | return; |
| 151 | dev = look_for_dev(card, device_data); |
| 152 | if (dev) |
| 153 | __snd_device_free(dev); |
| 154 | else |
| 155 | dev_dbg(card->dev, "device free %p (from %pF), not found\n", |
| 156 | device_data, __builtin_return_address(0)); |
| 157 | } |
| 158 | EXPORT_SYMBOL(snd_device_free); |
| 159 | |
| 160 | static int __snd_device_register(struct snd_device *dev) |
| 161 | { |
| 162 | if (dev->state == SNDRV_DEV_BUILD) { |
| 163 | if (dev->ops->dev_register) { |
| 164 | int err = dev->ops->dev_register(dev); |
| 165 | if (err < 0) |
| 166 | return err; |
| 167 | } |
| 168 | dev->state = SNDRV_DEV_REGISTERED; |
| 169 | } |
| 170 | return 0; |
| 171 | } |
| 172 | |
| 173 | /** |
| 174 | * snd_device_register - register the device |
| 175 | * @card: the card instance |
| 176 | * @device_data: the data pointer to register |
| 177 | * |
| 178 | * Registers the device which was already created via |
| 179 | * snd_device_new(). Usually this is called from snd_card_register(), |
| 180 | * but it can be called later if any new devices are created after |
| 181 | * invocation of snd_card_register(). |
| 182 | * |
| 183 | * Return: Zero if successful, or a negative error code on failure or if the |
| 184 | * device not found. |
| 185 | */ |
| 186 | int snd_device_register(struct snd_card *card, void *device_data) |
| 187 | { |
| 188 | struct snd_device *dev; |
| 189 | |
| 190 | if (snd_BUG_ON(!card || !device_data)) |
| 191 | return -ENXIO; |
| 192 | dev = look_for_dev(card, device_data); |
| 193 | if (dev) |
| 194 | return __snd_device_register(dev); |
| 195 | snd_BUG(); |
| 196 | return -ENXIO; |
| 197 | } |
| 198 | EXPORT_SYMBOL(snd_device_register); |
| 199 | |
| 200 | /* |
| 201 | * register all the devices on the card. |
| 202 | * called from init.c |
| 203 | */ |
| 204 | int snd_device_register_all(struct snd_card *card) |
| 205 | { |
| 206 | struct snd_device *dev; |
| 207 | int err; |
| 208 | |
| 209 | if (snd_BUG_ON(!card)) |
| 210 | return -ENXIO; |
| 211 | list_for_each_entry(dev, &card->devices, list) { |
| 212 | err = __snd_device_register(dev); |
| 213 | if (err < 0) |
| 214 | return err; |
| 215 | } |
| 216 | return 0; |
| 217 | } |
| 218 | |
| 219 | /* |
| 220 | * disconnect all the devices on the card. |
| 221 | * called from init.c |
| 222 | */ |
| 223 | void snd_device_disconnect_all(struct snd_card *card) |
| 224 | { |
| 225 | struct snd_device *dev; |
| 226 | |
| 227 | if (snd_BUG_ON(!card)) |
| 228 | return; |
| 229 | list_for_each_entry_reverse(dev, &card->devices, list) |
| 230 | __snd_device_disconnect(dev); |
| 231 | } |
| 232 | |
| 233 | /* |
| 234 | * release all the devices on the card. |
| 235 | * called from init.c |
| 236 | */ |
| 237 | void snd_device_free_all(struct snd_card *card) |
| 238 | { |
| 239 | struct snd_device *dev, *next; |
| 240 | |
| 241 | if (snd_BUG_ON(!card)) |
| 242 | return; |
| 243 | list_for_each_entry_safe_reverse(dev, next, &card->devices, list) |
| 244 | __snd_device_free(dev); |
| 245 | } |