vserver 1.9.5.x5
[linux-2.6.git] / sound / core / control.c
index c39afa6..91ecc3f 100644 (file)
@@ -22,6 +22,7 @@
 #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>
@@ -30,6 +31,9 @@
 #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;
@@ -62,7 +66,7 @@ static int snd_ctl_open(struct inode *inode, struct file *file)
                err = -EFAULT;
                goto __error2;
        }
-       ctl = snd_magic_kcalloc(snd_ctl_file_t, 0, GFP_KERNEL);
+       ctl = kcalloc(1, sizeof(*ctl), GFP_KERNEL);
        if (ctl == NULL) {
                err = -ENOMEM;
                goto __error;
@@ -108,7 +112,7 @@ static int snd_ctl_release(struct inode *inode, struct file *file)
        snd_kcontrol_t *control;
        unsigned int idx;
 
-       ctl = snd_magic_cast(snd_ctl_file_t, file->private_data, return -ENXIO);
+       ctl = file->private_data;
        fasync_helper(-1, file, 0, &ctl->fasync);
        file->private_data = NULL;
        card = ctl->card;
@@ -124,7 +128,7 @@ static int snd_ctl_release(struct inode *inode, struct file *file)
        }
        up_write(&card->controls_rwsem);
        snd_ctl_empty_read_queue(ctl);
-       snd_magic_kfree(ctl);
+       kfree(ctl);
        module_put(card->module);
        snd_card_file_remove(card, file);
        return 0;
@@ -155,7 +159,7 @@ void snd_ctl_notify(snd_card_t *card, unsigned int mask, snd_ctl_elem_id_t *id)
                                goto _found;
                        }
                }
-               ev = snd_kcalloc(sizeof(*ev), GFP_ATOMIC);
+               ev = kcalloc(1, sizeof(*ev), GFP_ATOMIC);
                if (ev) {
                        ev->id = *id;
                        ev->mask = mask;
@@ -188,9 +192,7 @@ snd_kcontrol_t *snd_ctl_new(snd_kcontrol_t * control, unsigned int access)
        
        snd_runtime_check(control != NULL, return NULL);
        snd_runtime_check(control->count > 0, return NULL);
-       kctl = (snd_kcontrol_t *)snd_magic_kcalloc(snd_kcontrol_t,
-                                                  sizeof(snd_kcontrol_volatile_t) * control->count,
-                                                  GFP_KERNEL);
+       kctl = kcalloc(1, sizeof(*kctl) + sizeof(snd_kcontrol_volatile_t) * control->count, GFP_KERNEL);
        if (kctl == NULL)
                return NULL;
        *kctl = *control;
@@ -249,7 +251,7 @@ void snd_ctl_free_one(snd_kcontrol_t * kcontrol)
        if (kcontrol) {
                if (kcontrol->private_free)
                        kcontrol->private_free(kcontrol);
-               snd_magic_kfree(kcontrol);
+               kfree(kcontrol);
        }
 }
 
@@ -636,19 +638,13 @@ static int snd_ctl_elem_info(snd_ctl_file_t *ctl, snd_ctl_elem_info_t __user *_i
        return result;
 }
 
-static int snd_ctl_elem_read(snd_card_t *card, snd_ctl_elem_value_t __user *_control)
+int snd_ctl_elem_read(snd_card_t *card, snd_ctl_elem_value_t *control)
 {
-       snd_ctl_elem_value_t *control;
        snd_kcontrol_t *kctl;
        snd_kcontrol_volatile_t *vd;
        unsigned int index_offset;
        int result, indirect;
-       
-       control = kmalloc(sizeof(*control), GFP_KERNEL);
-       if (control == NULL)
-               return -ENOMEM; 
-       if (copy_from_user(control, _control, sizeof(*control)))
-               return -EFAULT;
+
        down_read(&card->controls_rwsem);
        kctl = snd_ctl_find_id(card, &control->id);
        if (kctl == NULL) {
@@ -669,27 +665,36 @@ static int snd_ctl_elem_read(snd_card_t *card, snd_ctl_elem_value_t __user *_con
                }
        }
        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)))
-                       return -EFAULT;
+                       result = -EFAULT;
        kfree(control);
        return result;
 }
 
-static int snd_ctl_elem_write(snd_ctl_file_t *file, snd_ctl_elem_value_t __user *_control)
+int snd_ctl_elem_write(snd_card_t *card, snd_ctl_file_t *file, snd_ctl_elem_value_t *control)
 {
-       snd_card_t *card = file->card;
-       snd_ctl_elem_value_t *control;
        snd_kcontrol_t *kctl;
        snd_kcontrol_volatile_t *vd;
        unsigned int index_offset;
        int result, indirect;
 
-       control = kmalloc(sizeof(*control), GFP_KERNEL);
-       if (control == NULL)
-               return -ENOMEM; 
-       if (copy_from_user(control, _control, sizeof(*control)))
-               return -EFAULT;
        down_read(&card->controls_rwsem);
        kctl = snd_ctl_find_id(card, &control->id);
        if (kctl == NULL) {
@@ -703,7 +708,7 @@ static int snd_ctl_elem_write(snd_ctl_file_t *file, snd_ctl_elem_value_t __user
                } else {
                        if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
                            kctl->put == NULL ||
-                           (vd->owner != NULL && vd->owner != file)) {
+                           (file && vd->owner != NULL && vd->owner != file)) {
                                result = -EPERM;
                        } else {
                                snd_ctl_build_ioff(&control->id, kctl, index_offset);
@@ -712,16 +717,30 @@ static int snd_ctl_elem_write(snd_ctl_file_t *file, snd_ctl_elem_value_t __user
                        if (result > 0) {
                                up_read(&card->controls_rwsem);
                                snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
-                               result = 0;
-                               goto __unlocked;
+                               return 0;
                        }
                }
        }
        up_read(&card->controls_rwsem);
-      __unlocked:
+       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)))
-                       return -EFAULT;
+                       result = -EFAULT;
        kfree(control);
        return result;
 }
@@ -785,30 +804,21 @@ static int snd_ctl_elem_unlock(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_
 }
 
 struct user_element {
-       enum sndrv_ctl_elem_type type;  /* element type */
-       unsigned int elem_count;        /* count of elements */
-       union {
-               struct {
-                       unsigned int items;
-               } enumerated;
-       } u;
+       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 */
-       unsigned short dimen_count;     /* count of dimensions */
-       unsigned short dimen[0];        /* array of dimensions */
 };
 
 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->type = ue->type;
-       uinfo->count = ue->elem_count;
-       if (ue->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
-               uinfo->value.enumerated.items = ue->u.enumerated.items;
-               if (uinfo->value.enumerated.item >= ue->u.enumerated.items)
+       *uinfo = ue->info;
+       if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
+               uinfo->value.enumerated.items = ue->info.value.enumerated.items;
+               if (uinfo->value.enumerated.item >= ue->info.value.enumerated.items)
                        uinfo->value.enumerated.item = 0;
                strlcpy(uinfo->value.enumerated.name,
                        (char *)ue->priv_data + uinfo->value.enumerated.item * 64,
@@ -830,9 +840,10 @@ static int snd_ctl_elem_user_put(snd_kcontrol_t * kcontrol, snd_ctl_elem_value_t
        int change;
        struct user_element *ue = kcontrol->private_data;
        
-       change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size);
-       memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
-       return !!change;
+       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)
@@ -846,34 +857,35 @@ static int snd_ctl_elem_add(snd_ctl_file_t *file, snd_ctl_elem_info_t __user *_i
        snd_ctl_elem_info_t info;
        snd_kcontrol_t kctl, *_kctl;
        unsigned int access;
-       long private_size, dimen_size, extra_size;
+       long private_size, extra_size;
        struct user_element *ue;
        int idx, err;
        
+       if (card->user_ctl_count >= MAX_USER_CONTROLS)
+               return -ENOMEM;
        if (copy_from_user(&info, _info, sizeof(info)))
                return -EFAULT;
        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|
-                                SNDRV_CTL_ELEM_ACCESS_DINDIRECT|SNDRV_CTL_ELEM_ACCESS_INDIRECT));
-       if (access & (SNDRV_CTL_ELEM_ACCESS_DINDIRECT | SNDRV_CTL_ELEM_ACCESS_INDIRECT))
-               return -EINVAL;
+               (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);
-       if (!!((_kctl = snd_ctl_find_id(card, &info.id)) != NULL) ^ replace) {
-               up_write(&card->controls_rwsem);
-               return !replace ? -EBUSY : -ENOENT;
-       }
-       if (replace) {
-               err = snd_ctl_remove(card, _kctl);
-               if (err < 0) {
-                       up_write(&card->controls_rwsem);
-                       return err;
-               }
+       _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;
@@ -903,7 +915,7 @@ static int snd_ctl_elem_add(snd_ctl_file_t *file, snd_ctl_elem_info_t __user *_i
                private_size = sizeof(unsigned int);
                if (info.count > 128)
                        return -EINVAL;
-               if (info.value.enumerated.items > 1024)
+               if (info.value.enumerated.items > 128)
                        return -EINVAL;
                extra_size = info.value.enumerated.items * 64;
                break;
@@ -921,31 +933,18 @@ static int snd_ctl_elem_add(snd_ctl_file_t *file, snd_ctl_elem_info_t __user *_i
                return -EINVAL;
        }
        private_size *= info.count;
-       if (private_size > 1024 * 1024)
-               return -EINVAL;
-       dimen_size = 0;
-       if (!(info.access & SNDRV_CTL_ELEM_ACCESS_DINDIRECT))
-               for (idx = 0; idx < 4 && info.dimen.d[idx]; idx++)
-                       dimen_size += sizeof(unsigned short);
-       ue = snd_kcalloc(sizeof(struct user_element) + dimen_size + private_size + extra_size, GFP_KERNEL);
+       ue = kcalloc(1, sizeof(struct user_element) + private_size + extra_size, GFP_KERNEL);
        if (ue == NULL)
                return -ENOMEM;
-       ue->type = info.type;
-       ue->elem_count = info.count;
-       if (!(info.access & SNDRV_CTL_ELEM_ACCESS_DINDIRECT)) {
-               for (idx = 0; idx < 4 && info.dimen.d[idx]; idx++)
-                       ue->dimen[idx] = info.dimen.d[idx];
-               ue->dimen_count = dimen_size / sizeof(unsigned short);
-       }
-       ue->elem_data = (char *)ue + sizeof(ue) + dimen_size;
+       ue->info = info;
+       ue->elem_data = (char *)ue + sizeof(ue);
        ue->elem_data_size = private_size;
        if (extra_size) {
-               ue->priv_data = (char *)ue + sizeof(ue) + dimen_size + private_size;
+               ue->priv_data = (char *)ue + sizeof(ue) + private_size;
                ue->priv_data_size = extra_size;
-               if (ue->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
-                       if (copy_from_user(ue->priv_data, *(char **)info.value.enumerated.name, extra_size))
+               if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
+                       if (copy_from_user(ue->priv_data, *(char __user **)info.value.enumerated.name, extra_size))
                                return -EFAULT;
-                       ue->u.enumerated.items = info.value.enumerated.items;
                }
        }
        kctl.private_free = snd_ctl_elem_user_free;
@@ -962,16 +961,29 @@ static int snd_ctl_elem_add(snd_ctl_file_t *file, snd_ctl_elem_info_t __user *_i
                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_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;
-       return snd_ctl_remove_unlocked_id(file, &id);
+       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)
@@ -1003,18 +1015,23 @@ static int snd_ctl_set_power_state(snd_card_t *card, unsigned int power_state)
 {
        switch (power_state) {
        case SNDRV_CTL_POWER_D0:
-       case SNDRV_CTL_POWER_D1:
-       case SNDRV_CTL_POWER_D2:
-               if (card->power_state != power_state)
+               if (card->power_state != power_state) {
                        /* FIXME: pass the correct state value */
                        card->pm_resume(card, 0);
+                       snd_power_change_state(card, power_state);
+               }
                break;
        case SNDRV_CTL_POWER_D3hot:
-       case SNDRV_CTL_POWER_D3cold:
-               if (card->power_state != power_state)
+               if (card->power_state != power_state) {
                        /* FIXME: pass the correct state value */
                        card->pm_suspend(card, 0);
+                       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;
        }
@@ -1022,8 +1039,8 @@ static int snd_ctl_set_power_state(snd_card_t *card, unsigned int power_state)
 }
 #endif
 
-static insnd_ctl_ioctl(struct inode *inode, struct file *file,
-                        unsigned int cmd, unsigned long arg)
+static inline int _snd_ctl_ioctl(struct inode *inode, struct file *file,
+                                unsigned int cmd, unsigned long arg)
 {
        snd_ctl_file_t *ctl;
        snd_card_t *card;
@@ -1033,7 +1050,7 @@ static int snd_ctl_ioctl(struct inode *inode, struct file *file,
        int __user *ip = argp;
        int err;
 
-       ctl = snd_magic_cast(snd_ctl_file_t, file->private_data, return -ENXIO);
+       ctl = file->private_data;
        card = ctl->card;
        snd_assert(card != NULL, return -ENXIO);
        switch (cmd) {
@@ -1046,9 +1063,9 @@ static int snd_ctl_ioctl(struct inode *inode, struct file *file,
        case SNDRV_CTL_IOCTL_ELEM_INFO:
                return snd_ctl_elem_info(ctl, argp);
        case SNDRV_CTL_IOCTL_ELEM_READ:
-               return snd_ctl_elem_read(ctl->card, argp);
+               return snd_ctl_elem_read_user(ctl->card, argp);
        case SNDRV_CTL_IOCTL_ELEM_WRITE:
-               return snd_ctl_elem_write(ctl, argp);
+               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:
@@ -1096,13 +1113,24 @@ static int snd_ctl_ioctl(struct inode *inode, struct file *file,
        return -ENOTTY;
 }
 
+/* FIXME: need to unlock BKL to allow preemption */
+static int snd_ctl_ioctl(struct inode *inode, struct file *file,
+                        unsigned int cmd, unsigned long arg)
+{
+       int err;
+       unlock_kernel();
+       err = _snd_ctl_ioctl(inode, file, cmd, arg);
+       lock_kernel();
+       return err;
+}
+
 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 = snd_magic_cast(snd_ctl_file_t, file->private_data, return -ENXIO);
+       ctl = file->private_data;
        snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
        if (!ctl->subscribed)
                return -EBADFD;
@@ -1116,7 +1144,7 @@ static ssize_t snd_ctl_read(struct file *file, char __user *buffer, size_t count
                        wait_queue_t wait;
                        if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
                                err = -EAGAIN;
-                               goto __end;
+                               goto __end_lock;
                        }
                        init_waitqueue_entry(&wait, current);
                        add_wait_queue(&ctl->change_sleep, &wait);
@@ -1137,16 +1165,16 @@ static ssize_t snd_ctl_read(struct file *file, char __user *buffer, size_t count
                kfree(kev);
                if (copy_to_user(buffer, &ev, sizeof(snd_ctl_event_t))) {
                        err = -EFAULT;
-                       goto out;
+                       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:
+      __end_lock:
        spin_unlock_irq(&ctl->read_lock);
-out:
+      __end:
        return result > 0 ? result : err;
 }
 
@@ -1155,7 +1183,7 @@ static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
        unsigned int mask;
        snd_ctl_file_t *ctl;
 
-       ctl = snd_magic_cast(snd_ctl_file_t, file->private_data, return 0);
+       ctl = file->private_data;
        if (!ctl->subscribed)
                return 0;
        poll_wait(file, &ctl->change_sleep, wait);
@@ -1175,8 +1203,7 @@ int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
 {
        snd_kctl_ioctl_t *pn;
 
-       pn = (snd_kctl_ioctl_t *)
-               snd_kcalloc(sizeof(snd_kctl_ioctl_t), GFP_KERNEL);
+       pn = kcalloc(1, sizeof(snd_kctl_ioctl_t), GFP_KERNEL);
        if (pn == NULL)
                return -ENOMEM;
        pn->fioctl = fcn;
@@ -1214,7 +1241,7 @@ static int snd_ctl_fasync(int fd, struct file * file, int on)
 {
        snd_ctl_file_t *ctl;
        int err;
-       ctl = snd_magic_cast(snd_ctl_file_t, file->private_data, return -ENXIO);
+       ctl = file->private_data;
        err = fasync_helper(fd, file, on, &ctl->fasync);
        if (err < 0)
                return err;
@@ -1243,11 +1270,11 @@ static snd_minor_t snd_ctl_reg =
 };
 
 /*
- * registration of the control device:
- * called from init.c
+ * registration of the control device
  */
-int snd_ctl_register(snd_card_t *card)
+static int snd_ctl_dev_register(snd_device_t *device)
 {
+       snd_card_t *card = device->device_data;
        int err, cardnum;
        char name[16];
 
@@ -1262,11 +1289,11 @@ int snd_ctl_register(snd_card_t *card)
 }
 
 /*
- * disconnection of the control device:
- * called from init.c
+ * disconnection of the control device
  */
-int snd_ctl_disconnect(snd_card_t *card)
+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;
 
@@ -1281,19 +1308,13 @@ int snd_ctl_disconnect(snd_card_t *card)
 }
 
 /*
- * de-registration of the control device:
- * called from init.c
+ * free all controls
  */
-int snd_ctl_unregister(snd_card_t *card)
+static int snd_ctl_dev_free(snd_device_t *device)
 {
-       int err, cardnum;
+       snd_card_t *card = device->device_data;
        snd_kcontrol_t *control;
 
-       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;
        down_write(&card->controls_rwsem);
        while (!list_empty(&card->controls)) {
                control = snd_kcontrol(card->controls.next);
@@ -1302,3 +1323,36 @@ int snd_ctl_unregister(snd_card_t *card)
        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);
+}