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260 lines
6.4 KiB
260 lines
6.4 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Device management routines |
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* Copyright (c) by Jaroslav Kysela <[email protected]> |
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*/ |
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#include <linux/slab.h> |
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#include <linux/time.h> |
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#include <linux/export.h> |
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#include <linux/errno.h> |
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#include <sound/core.h> |
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/** |
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* snd_device_new - create an ALSA device component |
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* @card: the card instance |
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* @type: the device type, SNDRV_DEV_XXX |
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* @device_data: the data pointer of this device |
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* @ops: the operator table |
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* |
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* Creates a new device component for the given data pointer. |
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* The device will be assigned to the card and managed together |
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* by the card. |
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* |
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* The data pointer plays a role as the identifier, too, so the |
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* pointer address must be unique and unchanged. |
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* |
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* Return: Zero if successful, or a negative error code on failure. |
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*/ |
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int snd_device_new(struct snd_card *card, enum snd_device_type type, |
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void *device_data, const struct snd_device_ops *ops) |
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{ |
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struct snd_device *dev; |
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struct list_head *p; |
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if (snd_BUG_ON(!card || !device_data || !ops)) |
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return -ENXIO; |
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dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
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if (!dev) |
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return -ENOMEM; |
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INIT_LIST_HEAD(&dev->list); |
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dev->card = card; |
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dev->type = type; |
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dev->state = SNDRV_DEV_BUILD; |
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dev->device_data = device_data; |
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dev->ops = ops; |
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/* insert the entry in an incrementally sorted list */ |
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list_for_each_prev(p, &card->devices) { |
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struct snd_device *pdev = list_entry(p, struct snd_device, list); |
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if ((unsigned int)pdev->type <= (unsigned int)type) |
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break; |
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} |
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list_add(&dev->list, p); |
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return 0; |
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} |
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EXPORT_SYMBOL(snd_device_new); |
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static void __snd_device_disconnect(struct snd_device *dev) |
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{ |
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if (dev->state == SNDRV_DEV_REGISTERED) { |
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if (dev->ops->dev_disconnect && |
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dev->ops->dev_disconnect(dev)) |
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dev_err(dev->card->dev, "device disconnect failure\n"); |
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dev->state = SNDRV_DEV_DISCONNECTED; |
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} |
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} |
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static void __snd_device_free(struct snd_device *dev) |
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{ |
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/* unlink */ |
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list_del(&dev->list); |
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__snd_device_disconnect(dev); |
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if (dev->ops->dev_free) { |
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if (dev->ops->dev_free(dev)) |
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dev_err(dev->card->dev, "device free failure\n"); |
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} |
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kfree(dev); |
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} |
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static struct snd_device *look_for_dev(struct snd_card *card, void *device_data) |
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{ |
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struct snd_device *dev; |
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list_for_each_entry(dev, &card->devices, list) |
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if (dev->device_data == device_data) |
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return dev; |
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return NULL; |
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} |
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/** |
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* snd_device_disconnect - disconnect the device |
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* @card: the card instance |
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* @device_data: the data pointer to disconnect |
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* |
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* Turns the device into the disconnection state, invoking |
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* dev_disconnect callback, if the device was already registered. |
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* |
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* Usually called from snd_card_disconnect(). |
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* |
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* Return: Zero if successful, or a negative error code on failure or if the |
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* device not found. |
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*/ |
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void snd_device_disconnect(struct snd_card *card, void *device_data) |
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{ |
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struct snd_device *dev; |
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if (snd_BUG_ON(!card || !device_data)) |
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return; |
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dev = look_for_dev(card, device_data); |
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if (dev) |
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__snd_device_disconnect(dev); |
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else |
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dev_dbg(card->dev, "device disconnect %p (from %pS), not found\n", |
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device_data, __builtin_return_address(0)); |
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} |
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EXPORT_SYMBOL_GPL(snd_device_disconnect); |
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/** |
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* snd_device_free - release the device from the card |
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* @card: the card instance |
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* @device_data: the data pointer to release |
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* |
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* Removes the device from the list on the card and invokes the |
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* callbacks, dev_disconnect and dev_free, corresponding to the state. |
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* Then release the device. |
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*/ |
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void snd_device_free(struct snd_card *card, void *device_data) |
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{ |
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struct snd_device *dev; |
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if (snd_BUG_ON(!card || !device_data)) |
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return; |
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dev = look_for_dev(card, device_data); |
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if (dev) |
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__snd_device_free(dev); |
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else |
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dev_dbg(card->dev, "device free %p (from %pS), not found\n", |
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device_data, __builtin_return_address(0)); |
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} |
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EXPORT_SYMBOL(snd_device_free); |
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static int __snd_device_register(struct snd_device *dev) |
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{ |
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if (dev->state == SNDRV_DEV_BUILD) { |
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if (dev->ops->dev_register) { |
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int err = dev->ops->dev_register(dev); |
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if (err < 0) |
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return err; |
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} |
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dev->state = SNDRV_DEV_REGISTERED; |
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} |
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return 0; |
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} |
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/** |
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* snd_device_register - register the device |
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* @card: the card instance |
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* @device_data: the data pointer to register |
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* |
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* Registers the device which was already created via |
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* snd_device_new(). Usually this is called from snd_card_register(), |
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* but it can be called later if any new devices are created after |
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* invocation of snd_card_register(). |
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* |
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* Return: Zero if successful, or a negative error code on failure or if the |
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* device not found. |
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*/ |
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int snd_device_register(struct snd_card *card, void *device_data) |
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{ |
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struct snd_device *dev; |
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if (snd_BUG_ON(!card || !device_data)) |
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return -ENXIO; |
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dev = look_for_dev(card, device_data); |
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if (dev) |
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return __snd_device_register(dev); |
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snd_BUG(); |
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return -ENXIO; |
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} |
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EXPORT_SYMBOL(snd_device_register); |
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/* |
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* register all the devices on the card. |
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* called from init.c |
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*/ |
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int snd_device_register_all(struct snd_card *card) |
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{ |
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struct snd_device *dev; |
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int err; |
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if (snd_BUG_ON(!card)) |
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return -ENXIO; |
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list_for_each_entry(dev, &card->devices, list) { |
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err = __snd_device_register(dev); |
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if (err < 0) |
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return err; |
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} |
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return 0; |
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} |
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/* |
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* disconnect all the devices on the card. |
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* called from init.c |
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*/ |
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void snd_device_disconnect_all(struct snd_card *card) |
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{ |
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struct snd_device *dev; |
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if (snd_BUG_ON(!card)) |
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return; |
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list_for_each_entry_reverse(dev, &card->devices, list) |
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__snd_device_disconnect(dev); |
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} |
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/* |
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* release all the devices on the card. |
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* called from init.c |
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*/ |
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void snd_device_free_all(struct snd_card *card) |
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{ |
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struct snd_device *dev, *next; |
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if (snd_BUG_ON(!card)) |
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return; |
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list_for_each_entry_safe_reverse(dev, next, &card->devices, list) { |
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/* exception: free ctl and lowlevel stuff later */ |
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if (dev->type == SNDRV_DEV_CONTROL || |
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dev->type == SNDRV_DEV_LOWLEVEL) |
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continue; |
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__snd_device_free(dev); |
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} |
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/* free all */ |
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list_for_each_entry_safe_reverse(dev, next, &card->devices, list) |
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__snd_device_free(dev); |
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} |
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/** |
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* snd_device_get_state - Get the current state of the given device |
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* @card: the card instance |
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* @device_data: the data pointer to release |
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* |
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* Returns the current state of the given device object. For the valid |
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* device, either @SNDRV_DEV_BUILD, @SNDRV_DEV_REGISTERED or |
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* @SNDRV_DEV_DISCONNECTED is returned. |
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* Or for a non-existing device, -1 is returned as an error. |
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*/ |
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int snd_device_get_state(struct snd_card *card, void *device_data) |
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{ |
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struct snd_device *dev; |
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dev = look_for_dev(card, device_data); |
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if (dev) |
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return dev->state; |
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return -1; |
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} |
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EXPORT_SYMBOL_GPL(snd_device_get_state);
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