diff options
Diffstat (limited to 'kernel/sound/core/device.c')
-rw-r--r-- | kernel/sound/core/device.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/kernel/sound/core/device.c b/kernel/sound/core/device.c new file mode 100644 index 000000000..8918838b1 --- /dev/null +++ b/kernel/sound/core/device.c @@ -0,0 +1,245 @@ +/* + * Device management routines + * Copyright (c) by Jaroslav Kysela <perex@perex.cz> + * + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <linux/slab.h> +#include <linux/time.h> +#include <linux/export.h> +#include <linux/errno.h> +#include <sound/core.h> + +/** + * snd_device_new - create an ALSA device component + * @card: the card instance + * @type: the device type, SNDRV_DEV_XXX + * @device_data: the data pointer of this device + * @ops: the operator table + * + * Creates a new device component for the given data pointer. + * The device will be assigned to the card and managed together + * by the card. + * + * The data pointer plays a role as the identifier, too, so the + * pointer address must be unique and unchanged. + * + * Return: Zero if successful, or a negative error code on failure. + */ +int snd_device_new(struct snd_card *card, enum snd_device_type type, + void *device_data, struct snd_device_ops *ops) +{ + struct snd_device *dev; + struct list_head *p; + + if (snd_BUG_ON(!card || !device_data || !ops)) + return -ENXIO; + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return -ENOMEM; + INIT_LIST_HEAD(&dev->list); + dev->card = card; + dev->type = type; + dev->state = SNDRV_DEV_BUILD; + dev->device_data = device_data; + dev->ops = ops; + + /* insert the entry in an incrementally sorted list */ + list_for_each_prev(p, &card->devices) { + struct snd_device *pdev = list_entry(p, struct snd_device, list); + if ((unsigned int)pdev->type <= (unsigned int)type) + break; + } + + list_add(&dev->list, p); + return 0; +} +EXPORT_SYMBOL(snd_device_new); + +static void __snd_device_disconnect(struct snd_device *dev) +{ + if (dev->state == SNDRV_DEV_REGISTERED) { + if (dev->ops->dev_disconnect && + dev->ops->dev_disconnect(dev)) + dev_err(dev->card->dev, "device disconnect failure\n"); + dev->state = SNDRV_DEV_DISCONNECTED; + } +} + +static void __snd_device_free(struct snd_device *dev) +{ + /* unlink */ + list_del(&dev->list); + + __snd_device_disconnect(dev); + if (dev->ops->dev_free) { + if (dev->ops->dev_free(dev)) + dev_err(dev->card->dev, "device free failure\n"); + } + kfree(dev); +} + +static struct snd_device *look_for_dev(struct snd_card *card, void *device_data) +{ + struct snd_device *dev; + + list_for_each_entry(dev, &card->devices, list) + if (dev->device_data == device_data) + return dev; + + return NULL; +} + +/** + * snd_device_disconnect - disconnect the device + * @card: the card instance + * @device_data: the data pointer to disconnect + * + * Turns the device into the disconnection state, invoking + * dev_disconnect callback, if the device was already registered. + * + * Usually called from snd_card_disconnect(). + * + * Return: Zero if successful, or a negative error code on failure or if the + * device not found. + */ +void snd_device_disconnect(struct snd_card *card, void *device_data) +{ + struct snd_device *dev; + + if (snd_BUG_ON(!card || !device_data)) + return; + dev = look_for_dev(card, device_data); + if (dev) + __snd_device_disconnect(dev); + else + dev_dbg(card->dev, "device disconnect %p (from %pF), not found\n", + device_data, __builtin_return_address(0)); +} +EXPORT_SYMBOL_GPL(snd_device_disconnect); + +/** + * snd_device_free - release the device from the card + * @card: the card instance + * @device_data: the data pointer to release + * + * Removes the device from the list on the card and invokes the + * callbacks, dev_disconnect and dev_free, corresponding to the state. + * Then release the device. + */ +void snd_device_free(struct snd_card *card, void *device_data) +{ + struct snd_device *dev; + + if (snd_BUG_ON(!card || !device_data)) + return; + dev = look_for_dev(card, device_data); + if (dev) + __snd_device_free(dev); + else + dev_dbg(card->dev, "device free %p (from %pF), not found\n", + device_data, __builtin_return_address(0)); +} +EXPORT_SYMBOL(snd_device_free); + +static int __snd_device_register(struct snd_device *dev) +{ + if (dev->state == SNDRV_DEV_BUILD) { + if (dev->ops->dev_register) { + int err = dev->ops->dev_register(dev); + if (err < 0) + return err; + } + dev->state = SNDRV_DEV_REGISTERED; + } + return 0; +} + +/** + * snd_device_register - register the device + * @card: the card instance + * @device_data: the data pointer to register + * + * Registers the device which was already created via + * snd_device_new(). Usually this is called from snd_card_register(), + * but it can be called later if any new devices are created after + * invocation of snd_card_register(). + * + * Return: Zero if successful, or a negative error code on failure or if the + * device not found. + */ +int snd_device_register(struct snd_card *card, void *device_data) +{ + struct snd_device *dev; + + if (snd_BUG_ON(!card || !device_data)) + return -ENXIO; + dev = look_for_dev(card, device_data); + if (dev) + return __snd_device_register(dev); + snd_BUG(); + return -ENXIO; +} +EXPORT_SYMBOL(snd_device_register); + +/* + * register all the devices on the card. + * called from init.c + */ +int snd_device_register_all(struct snd_card *card) +{ + struct snd_device *dev; + int err; + + if (snd_BUG_ON(!card)) + return -ENXIO; + list_for_each_entry(dev, &card->devices, list) { + err = __snd_device_register(dev); + if (err < 0) + return err; + } + return 0; +} + +/* + * disconnect all the devices on the card. + * called from init.c + */ +void snd_device_disconnect_all(struct snd_card *card) +{ + struct snd_device *dev; + + if (snd_BUG_ON(!card)) + return; + list_for_each_entry_reverse(dev, &card->devices, list) + __snd_device_disconnect(dev); +} + +/* + * release all the devices on the card. + * called from init.c + */ +void snd_device_free_all(struct snd_card *card) +{ + struct snd_device *dev, *next; + + if (snd_BUG_ON(!card)) + return; + list_for_each_entry_safe_reverse(dev, next, &card->devices, list) + __snd_device_free(dev); +} |