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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /sound/core/device.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'sound/core/device.c')
-rw-r--r-- | sound/core/device.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/sound/core/device.c b/sound/core/device.c new file mode 100644 index 000000000..b57d80a17 --- /dev/null +++ b/sound/core/device.c @@ -0,0 +1,262 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Device management routines + * Copyright (c) by Jaroslav Kysela <perex@perex.cz> + */ + +#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, const 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 %pS), 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 %pS), 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) { + /* exception: free ctl and lowlevel stuff later */ + if (dev->type == SNDRV_DEV_CONTROL || + dev->type == SNDRV_DEV_LOWLEVEL) + continue; + __snd_device_free(dev); + } + + /* free all */ + list_for_each_entry_safe_reverse(dev, next, &card->devices, list) + __snd_device_free(dev); +} + +/** + * snd_device_get_state - Get the current state of the given device + * @card: the card instance + * @device_data: the data pointer to release + * + * Returns the current state of the given device object. For the valid + * device, either @SNDRV_DEV_BUILD, @SNDRV_DEV_REGISTERED or + * @SNDRV_DEV_DISCONNECTED is returned. + * Or for a non-existing device, -1 is returned as an error. + * + * Return: the current state, or -1 if not found + */ +int snd_device_get_state(struct snd_card *card, void *device_data) +{ + struct snd_device *dev; + + dev = look_for_dev(card, device_data); + if (dev) + return dev->state; + return -1; +} +EXPORT_SYMBOL_GPL(snd_device_get_state); |