linux/sound/core/device.c
Paul Gortmaker d81a6d7176 sound: Add export.h for THIS_MODULE/EXPORT_SYMBOL where needed
These aren't modules, but they do make use of these macros, so
they will need export.h to get that definition.  Previously,
they got it via the implicit module.h inclusion.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:22 -04:00

245 lines
6.6 KiB
C

/*
* 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.
*
* Returns zero if successful, or a negative error code on failure.
*/
int snd_device_new(struct snd_card *card, snd_device_type_t type,
void *device_data, struct snd_device_ops *ops)
{
struct snd_device *dev;
if (snd_BUG_ON(!card || !device_data || !ops))
return -ENXIO;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (dev == NULL) {
snd_printk(KERN_ERR "Cannot allocate device\n");
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;
}
EXPORT_SYMBOL(snd_device_new);
/**
* 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.
*
* Returns zero if successful, or a negative error code on failure or if the
* device not found.
*/
int snd_device_free(struct snd_card *card, void *device_data)
{
struct snd_device *dev;
if (snd_BUG_ON(!card || !device_data))
return -ENXIO;
list_for_each_entry(dev, &card->devices, list) {
if (dev->device_data != device_data)
continue;
/* unlink */
list_del(&dev->list);
if (dev->state == SNDRV_DEV_REGISTERED &&
dev->ops->dev_disconnect)
if (dev->ops->dev_disconnect(dev))
snd_printk(KERN_ERR
"device disconnect failure\n");
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 %pF), not found\n", device_data,
__builtin_return_address(0));
return -ENXIO;
}
EXPORT_SYMBOL(snd_device_free);
/**
* 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().
*
* Returns zero if successful, or a negative error code on failure or if the
* device not found.
*/
int snd_device_disconnect(struct snd_card *card, void *device_data)
{
struct snd_device *dev;
if (snd_BUG_ON(!card || !device_data))
return -ENXIO;
list_for_each_entry(dev, &card->devices, 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 %pF), 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(struct snd_card *card, void *device_data)
{
struct snd_device *dev;
int err;
if (snd_BUG_ON(!card || !device_data))
return -ENXIO;
list_for_each_entry(dev, &card->devices, 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;
}
snd_printd("snd_device_register busy\n");
return -EBUSY;
}
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) {
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(struct snd_card *card)
{
struct snd_device *dev;
int err = 0;
if (snd_BUG_ON(!card))
return -ENXIO;
list_for_each_entry(dev, &card->devices, 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(struct snd_card *card, snd_device_cmd_t cmd)
{
struct snd_device *dev;
int err;
unsigned int range_low, range_high, type;
if (snd_BUG_ON(!card))
return -ENXIO;
range_low = (__force unsigned int)cmd * SNDRV_DEV_TYPE_RANGE_SIZE;
range_high = range_low + SNDRV_DEV_TYPE_RANGE_SIZE - 1;
__again:
list_for_each_entry(dev, &card->devices, list) {
type = (__force unsigned int)dev->type;
if (type >= range_low && type <= range_high) {
if ((err = snd_device_free(card, dev->device_data)) < 0)
return err;
goto __again;
}
}
return 0;
}