linux/sound/core/device.c
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00

240 lines
5.8 KiB
C

// 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, 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);
}