diff options
Diffstat (limited to 'sound/core/device.c')
-rw-r--r-- | sound/core/device.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/sound/core/device.c b/sound/core/device.c new file mode 100644 index 000000000000..18c71f913d2a --- /dev/null +++ b/sound/core/device.c @@ -0,0 +1,240 @@ +/* + * Device management routines + * Copyright (c) by Jaroslav Kysela <perex@suse.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 <sound/driver.h> +#include <linux/slab.h> +#include <linux/time.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_TYPE_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. + * + * Returns zero if successful, or a negative error code on failure. + */ +int snd_device_new(snd_card_t *card, snd_device_type_t type, + void *device_data, snd_device_ops_t *ops) +{ + snd_device_t *dev; + + snd_assert(card != NULL && device_data != NULL && ops != NULL, return -ENXIO); + dev = kcalloc(1, sizeof(*dev), GFP_KERNEL); + if (dev == NULL) + return -ENOMEM; + dev->card = card; + dev->type = type; + dev->state = SNDRV_DEV_BUILD; + dev->device_data = device_data; + dev->ops = ops; + list_add(&dev->list, &card->devices); /* add to the head of list */ + return 0; +} + +/** + * 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 + * callback, dev_unregister or dev_free, corresponding to the state. + * Then release the device. + * + * Returns zero if successful, or a negative error code on failure or if the + * device not found. + */ +int snd_device_free(snd_card_t *card, void *device_data) +{ + struct list_head *list; + snd_device_t *dev; + + snd_assert(card != NULL, return -ENXIO); + snd_assert(device_data != NULL, return -ENXIO); + list_for_each(list, &card->devices) { + dev = snd_device(list); + if (dev->device_data != device_data) + continue; + /* unlink */ + list_del(&dev->list); + if ((dev->state == SNDRV_DEV_REGISTERED || dev->state == SNDRV_DEV_DISCONNECTED) && + dev->ops->dev_unregister) { + if (dev->ops->dev_unregister(dev)) + snd_printk(KERN_ERR "device unregister failure\n"); + } else { + if (dev->ops->dev_free) { + if (dev->ops->dev_free(dev)) + snd_printk(KERN_ERR "device free failure\n"); + } + } + kfree(dev); + return 0; + } + snd_printd("device free %p (from %p), not found\n", device_data, __builtin_return_address(0)); + return -ENXIO; +} + +/** + * snd_device_free - 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(). + * + * Returns zero if successful, or a negative error code on failure or if the + * device not found. + */ +int snd_device_disconnect(snd_card_t *card, void *device_data) +{ + struct list_head *list; + snd_device_t *dev; + + snd_assert(card != NULL, return -ENXIO); + snd_assert(device_data != NULL, return -ENXIO); + list_for_each(list, &card->devices) { + dev = snd_device(list); + if (dev->device_data != device_data) + continue; + if (dev->state == SNDRV_DEV_REGISTERED && dev->ops->dev_disconnect) { + if (dev->ops->dev_disconnect(dev)) + snd_printk(KERN_ERR "device disconnect failure\n"); + dev->state = SNDRV_DEV_DISCONNECTED; + } + return 0; + } + snd_printd("device disconnect %p (from %p), not found\n", device_data, __builtin_return_address(0)); + return -ENXIO; +} + +/** + * 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(). + * + * Returns zero if successful, or a negative error code on failure or if the + * device not found. + */ +int snd_device_register(snd_card_t *card, void *device_data) +{ + struct list_head *list; + snd_device_t *dev; + int err; + + snd_assert(card != NULL && device_data != NULL, return -ENXIO); + list_for_each(list, &card->devices) { + dev = snd_device(list); + if (dev->device_data != device_data) + continue; + if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) { + if ((err = dev->ops->dev_register(dev)) < 0) + return err; + dev->state = SNDRV_DEV_REGISTERED; + return 0; + } + return -EBUSY; + } + snd_BUG(); + return -ENXIO; +} + +/* + * register all the devices on the card. + * called from init.c + */ +int snd_device_register_all(snd_card_t *card) +{ + struct list_head *list; + snd_device_t *dev; + int err; + + snd_assert(card != NULL, return -ENXIO); + list_for_each(list, &card->devices) { + dev = snd_device(list); + if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) { + if ((err = dev->ops->dev_register(dev)) < 0) + return err; + dev->state = SNDRV_DEV_REGISTERED; + } + } + return 0; +} + +/* + * disconnect all the devices on the card. + * called from init.c + */ +int snd_device_disconnect_all(snd_card_t *card) +{ + snd_device_t *dev; + struct list_head *list; + int err = 0; + + snd_assert(card != NULL, return -ENXIO); + list_for_each(list, &card->devices) { + dev = snd_device(list); + if (snd_device_disconnect(card, dev->device_data) < 0) + err = -ENXIO; + } + return err; +} + +/* + * release all the devices on the card. + * called from init.c + */ +int snd_device_free_all(snd_card_t *card, snd_device_cmd_t cmd) +{ + snd_device_t *dev; + struct list_head *list; + int err; + unsigned int range_low, range_high; + + snd_assert(card != NULL, return -ENXIO); + range_low = cmd * SNDRV_DEV_TYPE_RANGE_SIZE; + range_high = range_low + SNDRV_DEV_TYPE_RANGE_SIZE - 1; + __again: + list_for_each(list, &card->devices) { + dev = snd_device(list); + if (dev->type >= range_low && dev->type <= range_high) { + if ((err = snd_device_free(card, dev->device_data)) < 0) + return err; + goto __again; + } + } + return 0; +} |