Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1375 insertions, 0 deletions

diff --git a/sound/core/control.c b/sound/core/control.c
new file mode 100644
index 0000000..f4ea6bf
--- /dev/null
+++ b/sound/core/control.c
@@ -0,0 +1,1375 @@
+/*
+ *  Routines for driver control interface
+ *  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/threads.h>
+#include <linux/interrupt.h>
+#include <linux/smp_lock.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/time.h>
+#include <sound/core.h>
+#include <sound/minors.h>
+#include <sound/info.h>
+#include <sound/control.h>
+
+/* max number of user-defined controls */
+#define MAX_USER_CONTROLS	32
+
+typedef struct _snd_kctl_ioctl {
+	struct list_head list;		/* list of all ioctls */
+	snd_kctl_ioctl_func_t fioctl;
+} snd_kctl_ioctl_t;
+
+#define snd_kctl_ioctl(n) list_entry(n, snd_kctl_ioctl_t, list)
+
+static DECLARE_RWSEM(snd_ioctl_rwsem);
+static LIST_HEAD(snd_control_ioctls);
+#ifdef CONFIG_COMPAT
+static LIST_HEAD(snd_control_compat_ioctls);
+#endif
+
+static int snd_ctl_open(struct inode *inode, struct file *file)
+{
+	int cardnum = SNDRV_MINOR_CARD(iminor(inode));
+	unsigned long flags;
+	snd_card_t *card;
+	snd_ctl_file_t *ctl;
+	int err;
+
+	card = snd_cards[cardnum];
+	if (!card) {
+		err = -ENODEV;
+		goto __error1;
+	}
+	err = snd_card_file_add(card, file);
+	if (err < 0) {
+		err = -ENODEV;
+		goto __error1;
+	}
+	if (!try_module_get(card->module)) {
+		err = -EFAULT;
+		goto __error2;
+	}
+	ctl = kcalloc(1, sizeof(*ctl), GFP_KERNEL);
+	if (ctl == NULL) {
+		err = -ENOMEM;
+		goto __error;
+	}
+	INIT_LIST_HEAD(&ctl->events);
+	init_waitqueue_head(&ctl->change_sleep);
+	spin_lock_init(&ctl->read_lock);
+	ctl->card = card;
+	ctl->pid = current->pid;
+	file->private_data = ctl;
+	write_lock_irqsave(&card->ctl_files_rwlock, flags);
+	list_add_tail(&ctl->list, &card->ctl_files);
+	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
+	return 0;
+
+      __error:
+	module_put(card->module);
+      __error2:
+	snd_card_file_remove(card, file);
+      __error1:
+      	return err;
+}
+
+static void snd_ctl_empty_read_queue(snd_ctl_file_t * ctl)
+{
+	snd_kctl_event_t *cread;
+	
+	spin_lock(&ctl->read_lock);
+	while (!list_empty(&ctl->events)) {
+		cread = snd_kctl_event(ctl->events.next);
+		list_del(&cread->list);
+		kfree(cread);
+	}
+	spin_unlock(&ctl->read_lock);
+}
+
+static int snd_ctl_release(struct inode *inode, struct file *file)
+{
+	unsigned long flags;
+	struct list_head *list;
+	snd_card_t *card;
+	snd_ctl_file_t *ctl;
+	snd_kcontrol_t *control;
+	unsigned int idx;
+
+	ctl = file->private_data;
+	fasync_helper(-1, file, 0, &ctl->fasync);
+	file->private_data = NULL;
+	card = ctl->card;
+	write_lock_irqsave(&card->ctl_files_rwlock, flags);
+	list_del(&ctl->list);
+	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
+	down_write(&card->controls_rwsem);
+	list_for_each(list, &card->controls) {
+		control = snd_kcontrol(list);
+		for (idx = 0; idx < control->count; idx++)
+			if (control->vd[idx].owner == ctl)
+				control->vd[idx].owner = NULL;
+	}
+	up_write(&card->controls_rwsem);
+	snd_ctl_empty_read_queue(ctl);
+	kfree(ctl);
+	module_put(card->module);
+	snd_card_file_remove(card, file);
+	return 0;
+}
+
+void snd_ctl_notify(snd_card_t *card, unsigned int mask, snd_ctl_elem_id_t *id)
+{
+	unsigned long flags;
+	struct list_head *flist;
+	snd_ctl_file_t *ctl;
+	snd_kctl_event_t *ev;
+	
+	snd_runtime_check(card != NULL && id != NULL, return);
+	read_lock(&card->ctl_files_rwlock);
+#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
+	card->mixer_oss_change_count++;
+#endif
+	list_for_each(flist, &card->ctl_files) {
+		struct list_head *elist;
+		ctl = snd_ctl_file(flist);
+		if (!ctl->subscribed)
+			continue;
+		spin_lock_irqsave(&ctl->read_lock, flags);
+		list_for_each(elist, &ctl->events) {
+			ev = snd_kctl_event(elist);
+			if (ev->id.numid == id->numid) {
+				ev->mask |= mask;
+				goto _found;
+			}
+		}
+		ev = kcalloc(1, sizeof(*ev), GFP_ATOMIC);
+		if (ev) {
+			ev->id = *id;
+			ev->mask = mask;
+			list_add_tail(&ev->list, &ctl->events);
+		} else {
+			snd_printk(KERN_ERR "No memory available to allocate event\n");
+		}
+	_found:
+		wake_up(&ctl->change_sleep);
+		spin_unlock_irqrestore(&ctl->read_lock, flags);
+		kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
+	}
+	read_unlock(&card->ctl_files_rwlock);
+}
+
+/**
+ * snd_ctl_new - create a control instance from the template
+ * @control: the control template
+ * @access: the default control access
+ *
+ * Allocates a new snd_kcontrol_t instance and copies the given template 
+ * to the new instance. It does not copy volatile data (access).
+ *
+ * Returns the pointer of the new instance, or NULL on failure.
+ */
+snd_kcontrol_t *snd_ctl_new(snd_kcontrol_t * control, unsigned int access)
+{
+	snd_kcontrol_t *kctl;
+	unsigned int idx;
+	
+	snd_runtime_check(control != NULL, return NULL);
+	snd_runtime_check(control->count > 0, return NULL);
+	kctl = kcalloc(1, sizeof(*kctl) + sizeof(snd_kcontrol_volatile_t) * control->count, GFP_KERNEL);
+	if (kctl == NULL)
+		return NULL;
+	*kctl = *control;
+	for (idx = 0; idx < kctl->count; idx++)
+		kctl->vd[idx].access = access;
+	return kctl;
+}
+
+/**
+ * snd_ctl_new1 - create a control instance from the template
+ * @ncontrol: the initialization record
+ * @private_data: the private data to set
+ *
+ * Allocates a new snd_kcontrol_t instance and initialize from the given 
+ * template.  When the access field of ncontrol is 0, it's assumed as
+ * READWRITE access. When the count field is 0, it's assumes as one.
+ *
+ * Returns the pointer of the newly generated instance, or NULL on failure.
+ */
+snd_kcontrol_t *snd_ctl_new1(snd_kcontrol_new_t * ncontrol, void *private_data)
+{
+	snd_kcontrol_t kctl;
+	unsigned int access;
+	
+	snd_runtime_check(ncontrol != NULL, return NULL);
+	snd_assert(ncontrol->info != NULL, return NULL);
+	memset(&kctl, 0, sizeof(kctl));
+	kctl.id.iface = ncontrol->iface;
+	kctl.id.device = ncontrol->device;
+	kctl.id.subdevice = ncontrol->subdevice;
+	if (ncontrol->name)
+		strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
+	kctl.id.index = ncontrol->index;
+	kctl.count = ncontrol->count ? ncontrol->count : 1;
+	access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
+		 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE|
+		 		      SNDRV_CTL_ELEM_ACCESS_DINDIRECT|SNDRV_CTL_ELEM_ACCESS_INDIRECT));
+	kctl.info = ncontrol->info;
+	kctl.get = ncontrol->get;
+	kctl.put = ncontrol->put;
+	kctl.private_value = ncontrol->private_value;
+	kctl.private_data = private_data;
+	return snd_ctl_new(&kctl, access);
+}
+
+/**
+ * snd_ctl_free_one - release the control instance
+ * @kcontrol: the control instance
+ *
+ * Releases the control instance created via snd_ctl_new()
+ * or snd_ctl_new1().
+ * Don't call this after the control was added to the card.
+ */
+void snd_ctl_free_one(snd_kcontrol_t * kcontrol)
+{
+	if (kcontrol) {
+		if (kcontrol->private_free)
+			kcontrol->private_free(kcontrol);
+		kfree(kcontrol);
+	}
+}
+
+static unsigned int snd_ctl_hole_check(snd_card_t * card,
+				       unsigned int count)
+{
+	struct list_head *list;
+	snd_kcontrol_t *kctl;
+
+	list_for_each(list, &card->controls) {
+		kctl = snd_kcontrol(list);
+		if ((kctl->id.numid <= card->last_numid &&
+		     kctl->id.numid + kctl->count > card->last_numid) ||
+		    (kctl->id.numid <= card->last_numid + count - 1 &&
+		     kctl->id.numid + kctl->count > card->last_numid + count - 1))
+		    	return card->last_numid = kctl->id.numid + kctl->count - 1;
+	}
+	return card->last_numid;
+}
+
+static int snd_ctl_find_hole(snd_card_t * card, unsigned int count)
+{
+	unsigned int last_numid, iter = 100000;
+
+	last_numid = card->last_numid;
+	while (last_numid != snd_ctl_hole_check(card, count)) {
+		if (--iter == 0) {
+			/* this situation is very unlikely */
+			snd_printk(KERN_ERR "unable to allocate new control numid\n");
+			return -ENOMEM;
+		}
+		last_numid = card->last_numid;
+	}
+	return 0;
+}
+
+/**
+ * snd_ctl_add - add the control instance to the card
+ * @card: the card instance
+ * @kcontrol: the control instance to add
+ *
+ * Adds the control instance created via snd_ctl_new() or
+ * snd_ctl_new1() to the given card. Assigns also an unique
+ * numid used for fast search.
+ *
+ * Returns zero if successful, or a negative error code on failure.
+ *
+ * It frees automatically the control which cannot be added.
+ */
+int snd_ctl_add(snd_card_t * card, snd_kcontrol_t * kcontrol)
+{
+	snd_ctl_elem_id_t id;
+	unsigned int idx;
+
+	snd_runtime_check(card != NULL && kcontrol != NULL, return -EINVAL);
+	snd_assert(kcontrol->info != NULL, return -EINVAL);
+	id = kcontrol->id;
+	down_write(&card->controls_rwsem);
+	if (snd_ctl_find_id(card, &id)) {
+		up_write(&card->controls_rwsem);
+		snd_ctl_free_one(kcontrol);
+		snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
+					id.iface,
+					id.device,
+					id.subdevice,
+					id.name,
+					id.index);
+		return -EBUSY;
+	}
+	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
+		up_write(&card->controls_rwsem);
+		snd_ctl_free_one(kcontrol);
+		return -ENOMEM;
+	}
+	list_add_tail(&kcontrol->list, &card->controls);
+	card->controls_count += kcontrol->count;
+	kcontrol->id.numid = card->last_numid + 1;
+	card->last_numid += kcontrol->count;
+	up_write(&card->controls_rwsem);
+	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
+		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
+	return 0;
+}
+
+/**
+ * snd_ctl_remove - remove the control from the card and release it
+ * @card: the card instance
+ * @kcontrol: the control instance to remove
+ *
+ * Removes the control from the card and then releases the instance.
+ * You don't need to call snd_ctl_free_one(). You must be in
+ * the write lock - down_write(&card->controls_rwsem).
+ * 
+ * Returns 0 if successful, or a negative error code on failure.
+ */
+int snd_ctl_remove(snd_card_t * card, snd_kcontrol_t * kcontrol)
+{
+	snd_ctl_elem_id_t id;
+	unsigned int idx;
+
+	snd_runtime_check(card != NULL && kcontrol != NULL, return -EINVAL);
+	list_del(&kcontrol->list);
+	card->controls_count -= kcontrol->count;
+	id = kcontrol->id;
+	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
+		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
+	snd_ctl_free_one(kcontrol);
+	return 0;
+}
+
+/**
+ * snd_ctl_remove_id - remove the control of the given id and release it
+ * @card: the card instance
+ * @id: the control id to remove
+ *
+ * Finds the control instance with the given id, removes it from the
+ * card list and releases it.
+ * 
+ * Returns 0 if successful, or a negative error code on failure.
+ */
+int snd_ctl_remove_id(snd_card_t * card, snd_ctl_elem_id_t *id)
+{
+	snd_kcontrol_t *kctl;
+	int ret;
+
+	down_write(&card->controls_rwsem);
+	kctl = snd_ctl_find_id(card, id);
+	if (kctl == NULL) {
+		up_write(&card->controls_rwsem);
+		return -ENOENT;
+	}
+	ret = snd_ctl_remove(card, kctl);
+	up_write(&card->controls_rwsem);
+	return ret;
+}
+
+/**
+ * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
+ * @file: active control handle
+ * @id: the control id to remove
+ *
+ * Finds the control instance with the given id, removes it from the
+ * card list and releases it.
+ * 
+ * Returns 0 if successful, or a negative error code on failure.
+ */
+static int snd_ctl_remove_unlocked_id(snd_ctl_file_t * file, snd_ctl_elem_id_t *id)
+{
+	snd_card_t *card = file->card;
+	snd_kcontrol_t *kctl;
+	int idx, ret;
+
+	down_write(&card->controls_rwsem);
+	kctl = snd_ctl_find_id(card, id);
+	if (kctl == NULL) {
+		up_write(&card->controls_rwsem);
+		return -ENOENT;
+	}
+	for (idx = 0; idx < kctl->count; idx++)
+		if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
+			up_write(&card->controls_rwsem);
+			return -EBUSY;
+		}
+	ret = snd_ctl_remove(card, kctl);
+	up_write(&card->controls_rwsem);
+	return ret;
+}
+
+/**
+ * snd_ctl_rename_id - replace the id of a control on the card
+ * @card: the card instance
+ * @src_id: the old id
+ * @dst_id: the new id
+ *
+ * Finds the control with the old id from the card, and replaces the
+ * id with the new one.
+ *
+ * Returns zero if successful, or a negative error code on failure.
+ */
+int snd_ctl_rename_id(snd_card_t * card, snd_ctl_elem_id_t *src_id, snd_ctl_elem_id_t *dst_id)
+{
+	snd_kcontrol_t *kctl;
+
+	down_write(&card->controls_rwsem);
+	kctl = snd_ctl_find_id(card, src_id);
+	if (kctl == NULL) {
+		up_write(&card->controls_rwsem);
+		return -ENOENT;
+	}
+	kctl->id = *dst_id;
+	kctl->id.numid = card->last_numid + 1;
+	card->last_numid += kctl->count;
+	up_write(&card->controls_rwsem);
+	return 0;
+}
+
+/**
+ * snd_ctl_find_numid - find the control instance with the given number-id
+ * @card: the card instance
+ * @numid: the number-id to search
+ *
+ * Finds the control instance with the given number-id from the card.
+ *
+ * Returns the pointer of the instance if found, or NULL if not.
+ *
+ * The caller must down card->controls_rwsem before calling this function
+ * (if the race condition can happen).
+ */
+snd_kcontrol_t *snd_ctl_find_numid(snd_card_t * card, unsigned int numid)
+{
+	struct list_head *list;
+	snd_kcontrol_t *kctl;
+
+	snd_runtime_check(card != NULL && numid != 0, return NULL);
+	list_for_each(list, &card->controls) {
+		kctl = snd_kcontrol(list);
+		if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
+			return kctl;
+	}
+	return NULL;
+}
+
+/**
+ * snd_ctl_find_id - find the control instance with the given id
+ * @card: the card instance
+ * @id: the id to search
+ *
+ * Finds the control instance with the given id from the card.
+ *
+ * Returns the pointer of the instance if found, or NULL if not.
+ *
+ * The caller must down card->controls_rwsem before calling this function
+ * (if the race condition can happen).
+ */
+snd_kcontrol_t *snd_ctl_find_id(snd_card_t * card, snd_ctl_elem_id_t *id)
+{
+	struct list_head *list;
+	snd_kcontrol_t *kctl;
+
+	snd_runtime_check(card != NULL && id != NULL, return NULL);
+	if (id->numid != 0)
+		return snd_ctl_find_numid(card, id->numid);
+	list_for_each(list, &card->controls) {
+		kctl = snd_kcontrol(list);
+		if (kctl->id.iface != id->iface)
+			continue;
+		if (kctl->id.device != id->device)
+			continue;
+		if (kctl->id.subdevice != id->subdevice)
+			continue;
+		if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
+			continue;
+		if (kctl->id.index > id->index)
+			continue;
+		if (kctl->id.index + kctl->count <= id->index)
+			continue;
+		return kctl;
+	}
+	return NULL;
+}
+
+static int snd_ctl_card_info(snd_card_t * card, snd_ctl_file_t * ctl,
+			     unsigned int cmd, void __user *arg)
+{
+	snd_ctl_card_info_t *info;
+
+	info = kcalloc(1, sizeof(*info), GFP_KERNEL);
+	if (! info)
+		return -ENOMEM;
+	down_read(&snd_ioctl_rwsem);
+	info->card = card->number;
+	strlcpy(info->id, card->id, sizeof(info->id));
+	strlcpy(info->driver, card->driver, sizeof(info->driver));
+	strlcpy(info->name, card->shortname, sizeof(info->name));
+	strlcpy(info->longname, card->longname, sizeof(info->longname));
+	strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
+	strlcpy(info->components, card->components, sizeof(info->components));
+	up_read(&snd_ioctl_rwsem);
+	if (copy_to_user(arg, info, sizeof(snd_ctl_card_info_t))) {
+		kfree(info);
+		return -EFAULT;
+	}
+	kfree(info);
+	return 0;
+}
+
+static int snd_ctl_elem_list(snd_card_t *card, snd_ctl_elem_list_t __user *_list)
+{
+	struct list_head *plist;
+	snd_ctl_elem_list_t list;
+	snd_kcontrol_t *kctl;
+	snd_ctl_elem_id_t *dst, *id;
+	unsigned int offset, space, first, jidx;
+	
+	if (copy_from_user(&list, _list, sizeof(list)))
+		return -EFAULT;
+	offset = list.offset;
+	space = list.space;
+	first = 0;
+	/* try limit maximum space */
+	if (space > 16384)
+		return -ENOMEM;
+	if (space > 0) {
+		/* allocate temporary buffer for atomic operation */
+		dst = vmalloc(space * sizeof(snd_ctl_elem_id_t));
+		if (dst == NULL)
+			return -ENOMEM;
+		down_read(&card->controls_rwsem);
+		list.count = card->controls_count;
+		plist = card->controls.next;
+		while (plist != &card->controls) {
+			if (offset == 0)
+				break;
+			kctl = snd_kcontrol(plist);
+			if (offset < kctl->count)
+				break;
+			offset -= kctl->count;
+			plist = plist->next;
+		}
+		list.used = 0;
+		id = dst;
+		while (space > 0 && plist != &card->controls) {
+			kctl = snd_kcontrol(plist);
+			for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
+				snd_ctl_build_ioff(id, kctl, jidx);
+				id++;
+				space--;
+				list.used++;
+			}
+			plist = plist->next;
+			offset = 0;
+		}
+		up_read(&card->controls_rwsem);
+		if (list.used > 0 && copy_to_user(list.pids, dst, list.used * sizeof(snd_ctl_elem_id_t))) {
+			vfree(dst);
+			return -EFAULT;
+		}
+		vfree(dst);
+	} else {
+		down_read(&card->controls_rwsem);
+		list.count = card->controls_count;
+		up_read(&card->controls_rwsem);
+	}
+	if (copy_to_user(_list, &list, sizeof(list)))
+		return -EFAULT;
+	return 0;
+}
+
+static int snd_ctl_elem_info(snd_ctl_file_t *ctl, snd_ctl_elem_info_t *info)
+{
+	snd_card_t *card = ctl->card;
+	snd_kcontrol_t *kctl;
+	snd_kcontrol_volatile_t *vd;
+	unsigned int index_offset;
+	int result;
+	
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_id(card, &info->id);
+	if (kctl == NULL) {
+		up_read(&card->controls_rwsem);
+		return -ENOENT;
+	}
+#ifdef CONFIG_SND_DEBUG
+	info->access = 0;
+#endif
+	result = kctl->info(kctl, info);
+	if (result >= 0) {
+		snd_assert(info->access == 0, );
+		index_offset = snd_ctl_get_ioff(kctl, &info->id);
+		vd = &kctl->vd[index_offset];
+		snd_ctl_build_ioff(&info->id, kctl, index_offset);
+		info->access = vd->access;
+		if (vd->owner) {
+			info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
+			if (vd->owner == ctl)
+				info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
+			info->owner = vd->owner_pid;
+		} else {
+			info->owner = -1;
+		}
+	}
+	up_read(&card->controls_rwsem);
+	return result;
+}
+
+static int snd_ctl_elem_info_user(snd_ctl_file_t *ctl, snd_ctl_elem_info_t __user *_info)
+{
+	snd_ctl_elem_info_t info;
+	int result;
+
+	if (copy_from_user(&info, _info, sizeof(info)))
+		return -EFAULT;
+	result = snd_ctl_elem_info(ctl, &info);
+	if (result >= 0)
+		if (copy_to_user(_info, &info, sizeof(info)))
+			return -EFAULT;
+	return result;
+}
+
+int snd_ctl_elem_read(snd_card_t *card, snd_ctl_elem_value_t *control)
+{
+	snd_kcontrol_t *kctl;
+	snd_kcontrol_volatile_t *vd;
+	unsigned int index_offset;
+	int result, indirect;
+
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_id(card, &control->id);
+	if (kctl == NULL) {
+		result = -ENOENT;
+	} else {
+		index_offset = snd_ctl_get_ioff(kctl, &control->id);
+		vd = &kctl->vd[index_offset];
+		indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
+		if (control->indirect != indirect) {
+			result = -EACCES;
+		} else {
+			if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
+				snd_ctl_build_ioff(&control->id, kctl, index_offset);
+				result = kctl->get(kctl, control);
+			} else {
+				result = -EPERM;
+			}
+		}
+	}
+	up_read(&card->controls_rwsem);
+	return result;
+}
+
+static int snd_ctl_elem_read_user(snd_card_t *card, snd_ctl_elem_value_t __user *_control)
+{
+	snd_ctl_elem_value_t *control;
+	int result;
+	
+	control = kmalloc(sizeof(*control), GFP_KERNEL);
+	if (control == NULL)
+		return -ENOMEM;	
+	if (copy_from_user(control, _control, sizeof(*control))) {
+		kfree(control);
+		return -EFAULT;
+	}
+	result = snd_ctl_elem_read(card, control);
+	if (result >= 0)
+		if (copy_to_user(_control, control, sizeof(*control)))
+			result = -EFAULT;
+	kfree(control);
+	return result;
+}
+
+int snd_ctl_elem_write(snd_card_t *card, snd_ctl_file_t *file, snd_ctl_elem_value_t *control)
+{
+	snd_kcontrol_t *kctl;
+	snd_kcontrol_volatile_t *vd;
+	unsigned int index_offset;
+	int result, indirect;
+
+	down_read(&card->controls_rwsem);
+	kctl = snd_ctl_find_id(card, &control->id);
+	if (kctl == NULL) {
+		result = -ENOENT;
+	} else {
+		index_offset = snd_ctl_get_ioff(kctl, &control->id);
+		vd = &kctl->vd[index_offset];
+		indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
+		if (control->indirect != indirect) {
+			result = -EACCES;
+		} else {
+			if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
+			    kctl->put == NULL ||
+			    (file && vd->owner != NULL && vd->owner != file)) {
+				result = -EPERM;
+			} else {
+				snd_ctl_build_ioff(&control->id, kctl, index_offset);
+				result = kctl->put(kctl, control);
+			}
+			if (result > 0) {
+				up_read(&card->controls_rwsem);
+				snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
+				return 0;
+			}
+		}
+	}
+	up_read(&card->controls_rwsem);
+	return result;
+}
+
+static int snd_ctl_elem_write_user(snd_ctl_file_t *file, snd_ctl_elem_value_t __user *_control)
+{
+	snd_ctl_elem_value_t *control;
+	int result;
+
+	control = kmalloc(sizeof(*control), GFP_KERNEL);
+	if (control == NULL)
+		return -ENOMEM;	
+	if (copy_from_user(control, _control, sizeof(*control))) {
+		kfree(control);
+		return -EFAULT;
+	}
+	result = snd_ctl_elem_write(file->card, file, control);
+	if (result >= 0)
+		if (copy_to_user(_control, control, sizeof(*control)))
+			result = -EFAULT;
+	kfree(control);
+	return result;
+}
+
+static int snd_ctl_elem_lock(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
+{
+	snd_card_t *card = file->card;
+	snd_ctl_elem_id_t id;
+	snd_kcontrol_t *kctl;
+	snd_kcontrol_volatile_t *vd;
+	int result;
+	
+	if (copy_from_user(&id, _id, sizeof(id)))
+		return -EFAULT;
+	down_write(&card->controls_rwsem);
+	kctl = snd_ctl_find_id(card, &id);
+	if (kctl == NULL) {
+		result = -ENOENT;
+	} else {
+		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
+		if (vd->owner != NULL)
+			result = -EBUSY;
+		else {
+			vd->owner = file;
+			vd->owner_pid = current->pid;
+			result = 0;
+		}
+	}
+	up_write(&card->controls_rwsem);
+	return result;
+}
+
+static int snd_ctl_elem_unlock(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
+{
+	snd_card_t *card = file->card;
+	snd_ctl_elem_id_t id;
+	snd_kcontrol_t *kctl;
+	snd_kcontrol_volatile_t *vd;
+	int result;
+	
+	if (copy_from_user(&id, _id, sizeof(id)))
+		return -EFAULT;
+	down_write(&card->controls_rwsem);
+	kctl = snd_ctl_find_id(card, &id);
+	if (kctl == NULL) {
+		result = -ENOENT;
+	} else {
+		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
+		if (vd->owner == NULL)
+			result = -EINVAL;
+		else if (vd->owner != file)
+			result = -EPERM;
+		else {
+			vd->owner = NULL;
+			vd->owner_pid = 0;
+			result = 0;
+		}
+	}
+	up_write(&card->controls_rwsem);
+	return result;
+}
+
+struct user_element {
+	snd_ctl_elem_info_t info;
+	void *elem_data;		/* element data */
+	unsigned long elem_data_size;	/* size of element data in bytes */
+	void *priv_data;		/* private data (like strings for enumerated type) */
+	unsigned long priv_data_size;	/* size of private data in bytes */
+};
+
+static int snd_ctl_elem_user_info(snd_kcontrol_t *kcontrol, snd_ctl_elem_info_t *uinfo)
+{
+	struct user_element *ue = kcontrol->private_data;
+
+	*uinfo = ue->info;
+	return 0;
+}
+
+static int snd_ctl_elem_user_get(snd_kcontrol_t * kcontrol, snd_ctl_elem_value_t * ucontrol)
+{
+	struct user_element *ue = kcontrol->private_data;
+
+	memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
+	return 0;
+}
+
+static int snd_ctl_elem_user_put(snd_kcontrol_t * kcontrol, snd_ctl_elem_value_t * ucontrol)
+{
+	int change;
+	struct user_element *ue = kcontrol->private_data;
+	
+	change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
+	if (change)
+		memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
+	return change;
+}
+
+static void snd_ctl_elem_user_free(snd_kcontrol_t * kcontrol)
+{
+	kfree(kcontrol->private_data);
+}
+
+static int snd_ctl_elem_add(snd_ctl_file_t *file, snd_ctl_elem_info_t *info, int replace)
+{
+	snd_card_t *card = file->card;
+	snd_kcontrol_t kctl, *_kctl;
+	unsigned int access;
+	long private_size;
+	struct user_element *ue;
+	int idx, err;
+	
+	if (card->user_ctl_count >= MAX_USER_CONTROLS)
+		return -ENOMEM;
+	if (info->count > 1024)
+		return -EINVAL;
+	access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
+		(info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE));
+	info->id.numid = 0;
+	memset(&kctl, 0, sizeof(kctl));
+	down_write(&card->controls_rwsem);
+	_kctl = snd_ctl_find_id(card, &info->id);
+	err = 0;
+	if (_kctl) {
+		if (replace)
+			err = snd_ctl_remove(card, _kctl);
+		else
+			err = -EBUSY;
+	} else {
+		if (replace)
+			err = -ENOENT;
+	}
+	up_write(&card->controls_rwsem);
+	if (err < 0)
+		return err;
+	memcpy(&kctl.id, &info->id, sizeof(info->id));
+	kctl.count = info->owner ? info->owner : 1;
+	access |= SNDRV_CTL_ELEM_ACCESS_USER;
+	kctl.info = snd_ctl_elem_user_info;
+	if (access & SNDRV_CTL_ELEM_ACCESS_READ)
+		kctl.get = snd_ctl_elem_user_get;
+	if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
+		kctl.put = snd_ctl_elem_user_put;
+	switch (info->type) {
+	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
+		private_size = sizeof(char);
+		if (info->count > 128)
+			return -EINVAL;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_INTEGER:
+		private_size = sizeof(long);
+		if (info->count > 128)
+			return -EINVAL;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
+		private_size = sizeof(long long);
+		if (info->count > 64)
+			return -EINVAL;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_BYTES:
+		private_size = sizeof(unsigned char);
+		if (info->count > 512)
+			return -EINVAL;
+		break;
+	case SNDRV_CTL_ELEM_TYPE_IEC958:
+		private_size = sizeof(struct sndrv_aes_iec958);
+		if (info->count != 1)
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+	private_size *= info->count;
+	ue = kcalloc(1, sizeof(struct user_element) + private_size, GFP_KERNEL);
+	if (ue == NULL)
+		return -ENOMEM;
+	ue->info = *info;
+	ue->elem_data = (char *)ue + sizeof(*ue);
+	ue->elem_data_size = private_size;
+	kctl.private_free = snd_ctl_elem_user_free;
+	_kctl = snd_ctl_new(&kctl, access);
+	if (_kctl == NULL) {
+		kfree(_kctl->private_data);
+		return -ENOMEM;
+	}
+	_kctl->private_data = ue;
+	for (idx = 0; idx < _kctl->count; idx++)
+		_kctl->vd[idx].owner = file;
+	err = snd_ctl_add(card, _kctl);
+	if (err < 0) {
+		snd_ctl_free_one(_kctl);
+		return err;
+	}
+
+	down_write(&card->controls_rwsem);
+	card->user_ctl_count++;
+	up_write(&card->controls_rwsem);
+
+	return 0;
+}
+
+static int snd_ctl_elem_add_user(snd_ctl_file_t *file, snd_ctl_elem_info_t __user *_info, int replace)
+{
+	snd_ctl_elem_info_t info;
+	if (copy_from_user(&info, _info, sizeof(info)))
+		return -EFAULT;
+	return snd_ctl_elem_add(file, &info, replace);
+}
+
+static int snd_ctl_elem_remove(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
+{
+	snd_ctl_elem_id_t id;
+	int err;
+
+	if (copy_from_user(&id, _id, sizeof(id)))
+		return -EFAULT;
+	err = snd_ctl_remove_unlocked_id(file, &id);
+	if (! err) {
+		snd_card_t *card = file->card;
+		down_write(&card->controls_rwsem);
+		card->user_ctl_count--;
+		up_write(&card->controls_rwsem);
+	}
+	return err;
+}
+
+static int snd_ctl_subscribe_events(snd_ctl_file_t *file, int __user *ptr)
+{
+	int subscribe;
+	if (get_user(subscribe, ptr))
+		return -EFAULT;
+	if (subscribe < 0) {
+		subscribe = file->subscribed;
+		if (put_user(subscribe, ptr))
+			return -EFAULT;
+		return 0;
+	}
+	if (subscribe) {
+		file->subscribed = 1;
+		return 0;
+	} else if (file->subscribed) {
+		snd_ctl_empty_read_queue(file);
+		file->subscribed = 0;
+	}
+	return 0;
+}
+
+#ifdef CONFIG_PM
+/*
+ * change the power state
+ */
+static int snd_ctl_set_power_state(snd_card_t *card, unsigned int power_state)
+{
+	switch (power_state) {
+	case SNDRV_CTL_POWER_D0:
+		if (card->power_state != power_state) {
+			card->pm_resume(card);
+			snd_power_change_state(card, power_state);
+		}
+		break;
+	case SNDRV_CTL_POWER_D3hot:
+		if (card->power_state != power_state) {
+			card->pm_suspend(card, PMSG_SUSPEND);
+			snd_power_change_state(card, power_state);
+		}
+		break;
+	case SNDRV_CTL_POWER_D1:
+	case SNDRV_CTL_POWER_D2:
+	case SNDRV_CTL_POWER_D3cold:
+		/* not supported yet */
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+#endif
+
+static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	snd_ctl_file_t *ctl;
+	snd_card_t *card;
+	struct list_head *list;
+	snd_kctl_ioctl_t *p;
+	void __user *argp = (void __user *)arg;
+	int __user *ip = argp;
+	int err;
+
+	ctl = file->private_data;
+	card = ctl->card;
+	snd_assert(card != NULL, return -ENXIO);
+	switch (cmd) {
+	case SNDRV_CTL_IOCTL_PVERSION:
+		return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
+	case SNDRV_CTL_IOCTL_CARD_INFO:
+		return snd_ctl_card_info(card, ctl, cmd, argp);
+	case SNDRV_CTL_IOCTL_ELEM_LIST:
+		return snd_ctl_elem_list(ctl->card, argp);
+	case SNDRV_CTL_IOCTL_ELEM_INFO:
+		return snd_ctl_elem_info_user(ctl, argp);
+	case SNDRV_CTL_IOCTL_ELEM_READ:
+		return snd_ctl_elem_read_user(ctl->card, argp);
+	case SNDRV_CTL_IOCTL_ELEM_WRITE:
+		return snd_ctl_elem_write_user(ctl, argp);
+	case SNDRV_CTL_IOCTL_ELEM_LOCK:
+		return snd_ctl_elem_lock(ctl, argp);
+	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
+		return snd_ctl_elem_unlock(ctl, argp);
+	case SNDRV_CTL_IOCTL_ELEM_ADD:
+		return snd_ctl_elem_add_user(ctl, argp, 0);
+	case SNDRV_CTL_IOCTL_ELEM_REPLACE:
+		return snd_ctl_elem_add_user(ctl, argp, 1);
+	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
+		return snd_ctl_elem_remove(ctl, argp);
+	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
+		return snd_ctl_subscribe_events(ctl, ip);
+	case SNDRV_CTL_IOCTL_POWER:
+		if (get_user(err, ip))
+			return -EFAULT;
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+#ifdef CONFIG_PM
+		if (card->pm_suspend && card->pm_resume) {
+			snd_power_lock(card);
+			err = snd_ctl_set_power_state(card, err);
+			snd_power_unlock(card);
+		} else
+#endif
+			err = -ENOPROTOOPT;
+		return err;
+	case SNDRV_CTL_IOCTL_POWER_STATE:
+#ifdef CONFIG_PM
+		return put_user(card->power_state, ip) ? -EFAULT : 0;
+#else
+		return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
+#endif
+	}
+	down_read(&snd_ioctl_rwsem);
+	list_for_each(list, &snd_control_ioctls) {
+		p = list_entry(list, snd_kctl_ioctl_t, list);
+		err = p->fioctl(card, ctl, cmd, arg);
+		if (err != -ENOIOCTLCMD) {
+			up_read(&snd_ioctl_rwsem);
+			return err;
+		}
+	}
+	up_read(&snd_ioctl_rwsem);
+	snd_printd("unknown ioctl = 0x%x\n", cmd);
+	return -ENOTTY;
+}
+
+static ssize_t snd_ctl_read(struct file *file, char __user *buffer, size_t count, loff_t * offset)
+{
+	snd_ctl_file_t *ctl;
+	int err = 0;
+	ssize_t result = 0;
+
+	ctl = file->private_data;
+	snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
+	if (!ctl->subscribed)
+		return -EBADFD;
+	if (count < sizeof(snd_ctl_event_t))
+		return -EINVAL;
+	spin_lock_irq(&ctl->read_lock);
+	while (count >= sizeof(snd_ctl_event_t)) {
+		snd_ctl_event_t ev;
+		snd_kctl_event_t *kev;
+		while (list_empty(&ctl->events)) {
+			wait_queue_t wait;
+			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
+				err = -EAGAIN;
+				goto __end_lock;
+			}
+			init_waitqueue_entry(&wait, current);
+			add_wait_queue(&ctl->change_sleep, &wait);
+			set_current_state(TASK_INTERRUPTIBLE);
+			spin_unlock_irq(&ctl->read_lock);
+			schedule();
+			remove_wait_queue(&ctl->change_sleep, &wait);
+			if (signal_pending(current))
+				return result > 0 ? result : -ERESTARTSYS;
+			spin_lock_irq(&ctl->read_lock);
+		}
+		kev = snd_kctl_event(ctl->events.next);
+		ev.type = SNDRV_CTL_EVENT_ELEM;
+		ev.data.elem.mask = kev->mask;
+		ev.data.elem.id = kev->id;
+		list_del(&kev->list);
+		spin_unlock_irq(&ctl->read_lock);
+		kfree(kev);
+		if (copy_to_user(buffer, &ev, sizeof(snd_ctl_event_t))) {
+			err = -EFAULT;
+			goto __end;
+		}
+		spin_lock_irq(&ctl->read_lock);
+		buffer += sizeof(snd_ctl_event_t);
+		count -= sizeof(snd_ctl_event_t);
+		result += sizeof(snd_ctl_event_t);
+	}
+      __end_lock:
+	spin_unlock_irq(&ctl->read_lock);
+      __end:
+      	return result > 0 ? result : err;
+}
+
+static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
+{
+	unsigned int mask;
+	snd_ctl_file_t *ctl;
+
+	ctl = file->private_data;
+	if (!ctl->subscribed)
+		return 0;
+	poll_wait(file, &ctl->change_sleep, wait);
+
+	mask = 0;
+	if (!list_empty(&ctl->events))
+		mask |= POLLIN | POLLRDNORM;
+
+	return mask;
+}
+
+/*
+ * register the device-specific control-ioctls.
+ * called from each device manager like pcm.c, hwdep.c, etc.
+ */
+static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
+{
+	snd_kctl_ioctl_t *pn;
+
+	pn = kcalloc(1, sizeof(snd_kctl_ioctl_t), GFP_KERNEL);
+	if (pn == NULL)
+		return -ENOMEM;
+	pn->fioctl = fcn;
+	down_write(&snd_ioctl_rwsem);
+	list_add_tail(&pn->list, lists);
+	up_write(&snd_ioctl_rwsem);
+	return 0;
+}
+
+int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
+{
+	return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
+}
+
+#ifdef CONFIG_COMPAT
+int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
+{
+	return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
+}
+#endif
+
+/*
+ * de-register the device-specific control-ioctls.
+ */
+static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
+{
+	struct list_head *list;
+	snd_kctl_ioctl_t *p;
+
+	snd_runtime_check(fcn != NULL, return -EINVAL);
+	down_write(&snd_ioctl_rwsem);
+	list_for_each(list, lists) {
+		p = list_entry(list, snd_kctl_ioctl_t, list);
+		if (p->fioctl == fcn) {
+			list_del(&p->list);
+			up_write(&snd_ioctl_rwsem);
+			kfree(p);
+			return 0;
+		}
+	}
+	up_write(&snd_ioctl_rwsem);
+	snd_BUG();
+	return -EINVAL;
+}
+
+int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
+{
+	return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
+}
+
+#ifdef CONFIG_COMPAT
+int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
+{
+	return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
+}
+
+#endif
+
+static int snd_ctl_fasync(int fd, struct file * file, int on)
+{
+	snd_ctl_file_t *ctl;
+	int err;
+	ctl = file->private_data;
+	err = fasync_helper(fd, file, on, &ctl->fasync);
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+/*
+ * ioctl32 compat
+ */
+#ifdef CONFIG_COMPAT
+#include "control_compat.c"
+#else
+#define snd_ctl_ioctl_compat	NULL
+#endif
+
+/*
+ *  INIT PART
+ */
+
+static struct file_operations snd_ctl_f_ops =
+{
+	.owner =	THIS_MODULE,
+	.read =		snd_ctl_read,
+	.open =		snd_ctl_open,
+	.release =	snd_ctl_release,
+	.poll =		snd_ctl_poll,
+	.unlocked_ioctl =	snd_ctl_ioctl,
+	.compat_ioctl =	snd_ctl_ioctl_compat,
+	.fasync =	snd_ctl_fasync,
+};
+
+static snd_minor_t snd_ctl_reg =
+{
+	.comment =	"ctl",
+	.f_ops =	&snd_ctl_f_ops,
+};
+
+/*
+ * registration of the control device
+ */
+static int snd_ctl_dev_register(snd_device_t *device)
+{
+	snd_card_t *card = device->device_data;
+	int err, cardnum;
+	char name[16];
+
+	snd_assert(card != NULL, return -ENXIO);
+	cardnum = card->number;
+	snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
+	sprintf(name, "controlC%i", cardnum);
+	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL,
+					card, 0, &snd_ctl_reg, name)) < 0)
+		return err;
+	return 0;
+}
+
+/*
+ * disconnection of the control device
+ */
+static int snd_ctl_dev_disconnect(snd_device_t *device)
+{
+	snd_card_t *card = device->device_data;
+	struct list_head *flist;
+	snd_ctl_file_t *ctl;
+
+	down_read(&card->controls_rwsem);
+	list_for_each(flist, &card->ctl_files) {
+		ctl = snd_ctl_file(flist);
+		wake_up(&ctl->change_sleep);
+		kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
+	}
+	up_read(&card->controls_rwsem);
+	return 0;
+}
+
+/*
+ * free all controls
+ */
+static int snd_ctl_dev_free(snd_device_t *device)
+{
+	snd_card_t *card = device->device_data;
+	snd_kcontrol_t *control;
+
+	down_write(&card->controls_rwsem);
+	while (!list_empty(&card->controls)) {
+		control = snd_kcontrol(card->controls.next);
+		snd_ctl_remove(card, control);
+	}
+	up_write(&card->controls_rwsem);
+	return 0;
+}
+
+/*
+ * de-registration of the control device
+ */
+static int snd_ctl_dev_unregister(snd_device_t *device)
+{
+	snd_card_t *card = device->device_data;
+	int err, cardnum;
+
+	snd_assert(card != NULL, return -ENXIO);
+	cardnum = card->number;
+	snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
+	if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL, card, 0)) < 0)
+		return err;
+	return snd_ctl_dev_free(device);
+}
+
+/*
+ * create control core:
+ * called from init.c
+ */
+int snd_ctl_create(snd_card_t *card)
+{
+	static snd_device_ops_t ops = {
+		.dev_free = snd_ctl_dev_free,
+		.dev_register =	snd_ctl_dev_register,
+		.dev_disconnect = snd_ctl_dev_disconnect,
+		.dev_unregister = snd_ctl_dev_unregister
+	};
+
+	snd_assert(card != NULL, return -ENXIO);
+	return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
+}