/* * Routines for driver control interface * 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/threads.h> #include <linux/interrupt.h> #include <linux/module.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 #define MAX_CONTROL_COUNT 1028 struct snd_kctl_ioctl { struct list_head list; /* list of all ioctls */ snd_kctl_ioctl_func_t fioctl; }; 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) { unsigned long flags; struct snd_card *card; struct snd_ctl_file *ctl; int i, err; err = nonseekable_open(inode, file); if (err < 0) return err; card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL); 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 = kzalloc(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; for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++) ctl->preferred_subdevice[i] = -1; ctl->pid = get_pid(task_pid(current)); 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); snd_card_unref(card); return 0; __error: module_put(card->module); __error2: snd_card_file_remove(card, file); __error1: if (card) snd_card_unref(card); return err; } static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl) { unsigned long flags; struct snd_kctl_event *cread; spin_lock_irqsave(&ctl->read_lock, flags); while (!list_empty(&ctl->events)) { cread = snd_kctl_event(ctl->events.next); list_del(&cread->list); kfree(cread); } spin_unlock_irqrestore(&ctl->read_lock, flags); } static int snd_ctl_release(struct inode *inode, struct file *file) { unsigned long flags; struct snd_card *card; struct snd_ctl_file *ctl; struct snd_kcontrol *control; unsigned int idx; ctl = file->private_data; 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_entry(control, &card->controls, 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); put_pid(ctl->pid); kfree(ctl); module_put(card->module); snd_card_file_remove(card, file); return 0; } /** * snd_ctl_notify - Send notification to user-space for a control change * @card: the card to send notification * @mask: the event mask, SNDRV_CTL_EVENT_* * @id: the ctl element id to send notification * * This function adds an event record with the given id and mask, appends * to the list and wakes up the user-space for notification. This can be * called in the atomic context. */ void snd_ctl_notify(struct snd_card *card, unsigned int mask, struct snd_ctl_elem_id *id) { unsigned long flags; struct snd_ctl_file *ctl; struct snd_kctl_event *ev; if (snd_BUG_ON(!card || !id)) return; read_lock(&card->ctl_files_rwlock); #if IS_ENABLED(CONFIG_SND_MIXER_OSS) card->mixer_oss_change_count++; #endif list_for_each_entry(ctl, &card->ctl_files, list) { if (!ctl->subscribed) continue; spin_lock_irqsave(&ctl->read_lock, flags); list_for_each_entry(ev, &ctl->events, list) { if (ev->id.numid == id->numid) { ev->mask |= mask; goto _found; } } ev = kzalloc(sizeof(*ev), GFP_ATOMIC); if (ev) { ev->id = *id; ev->mask = mask; list_add_tail(&ev->list, &ctl->events); } else { dev_err(card->dev, "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); } EXPORT_SYMBOL(snd_ctl_notify); /** * snd_ctl_new - create a new control instance with some elements * @kctl: the pointer to store new control instance * @count: the number of elements in this control * @access: the default access flags for elements in this control * @file: given when locking these elements * * Allocates a memory object for a new control instance. The instance has * elements as many as the given number (@count). Each element has given * access permissions (@access). Each element is locked when @file is given. * * Return: 0 on success, error code on failure */ static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count, unsigned int access, struct snd_ctl_file *file) { unsigned int size; unsigned int idx; if (count == 0 || count > MAX_CONTROL_COUNT) return -EINVAL; size = sizeof(struct snd_kcontrol); size += sizeof(struct snd_kcontrol_volatile) * count; *kctl = kzalloc(size, GFP_KERNEL); if (!*kctl) return -ENOMEM; for (idx = 0; idx < count; idx++) { (*kctl)->vd[idx].access = access; (*kctl)->vd[idx].owner = file; } (*kctl)->count = count; return 0; } /** * snd_ctl_new1 - create a control instance from the template * @ncontrol: the initialization record * @private_data: the private data to set * * Allocates a new struct snd_kcontrol 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. * * Return: The pointer of the newly generated instance, or %NULL on failure. */ struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol, void *private_data) { struct snd_kcontrol *kctl; unsigned int count; unsigned int access; int err; if (snd_BUG_ON(!ncontrol || !ncontrol->info)) return NULL; count = ncontrol->count; if (count == 0) count = 1; access = ncontrol->access; if (access == 0) access = SNDRV_CTL_ELEM_ACCESS_READWRITE; access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE | SNDRV_CTL_ELEM_ACCESS_VOLATILE | SNDRV_CTL_ELEM_ACCESS_INACTIVE | SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE | SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND | SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK); err = snd_ctl_new(&kctl, count, access, NULL); if (err < 0) return NULL; /* The 'numid' member is decided when calling snd_ctl_add(). */ 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)); if (strcmp(ncontrol->name, kctl->id.name) != 0) pr_warn("ALSA: Control name '%s' truncated to '%s'\n", ncontrol->name, kctl->id.name); } kctl->id.index = ncontrol->index; kctl->info = ncontrol->info; kctl->get = ncontrol->get; kctl->put = ncontrol->put; kctl->tlv.p = ncontrol->tlv.p; kctl->private_value = ncontrol->private_value; kctl->private_data = private_data; return kctl; } EXPORT_SYMBOL(snd_ctl_new1); /** * 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(struct snd_kcontrol *kcontrol) { if (kcontrol) { if (kcontrol->private_free) kcontrol->private_free(kcontrol); kfree(kcontrol); } } EXPORT_SYMBOL(snd_ctl_free_one); static bool snd_ctl_remove_numid_conflict(struct snd_card *card, unsigned int count) { struct snd_kcontrol *kctl; /* Make sure that the ids assigned to the control do not wrap around */ if (card->last_numid >= UINT_MAX - count) card->last_numid = 0; list_for_each_entry(kctl, &card->controls, list) { if (kctl->id.numid < card->last_numid + 1 + count && kctl->id.numid + kctl->count > card->last_numid + 1) { card->last_numid = kctl->id.numid + kctl->count - 1; return true; } } return false; } static int snd_ctl_find_hole(struct snd_card *card, unsigned int count) { unsigned int iter = 100000; while (snd_ctl_remove_numid_conflict(card, count)) { if (--iter == 0) { /* this situation is very unlikely */ dev_err(card->dev, "unable to allocate new control numid\n"); return -ENOMEM; } } 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. * * It frees automatically the control which cannot be added. * * Return: Zero if successful, or a negative error code on failure. * */ int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol) { struct snd_ctl_elem_id id; unsigned int idx; unsigned int count; int err = -EINVAL; if (! kcontrol) return err; if (snd_BUG_ON(!card || !kcontrol->info)) goto error; id = kcontrol->id; if (id.index > UINT_MAX - kcontrol->count) goto error; down_write(&card->controls_rwsem); if (snd_ctl_find_id(card, &id)) { up_write(&card->controls_rwsem); dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n", id.iface, id.device, id.subdevice, id.name, id.index); err = -EBUSY; goto error; } if (snd_ctl_find_hole(card, kcontrol->count) < 0) { up_write(&card->controls_rwsem); err = -ENOMEM; goto error; } list_add_tail(&kcontrol->list, &card->controls); card->controls_count += kcontrol->count; kcontrol->id.numid = card->last_numid + 1; card->last_numid += kcontrol->count; id = kcontrol->id; count = kcontrol->count; up_write(&card->controls_rwsem); for (idx = 0; idx < count; idx++, id.index++, id.numid++) snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id); return 0; error: snd_ctl_free_one(kcontrol); return err; } EXPORT_SYMBOL(snd_ctl_add); /** * snd_ctl_replace - replace the control instance of the card * @card: the card instance * @kcontrol: the control instance to replace * @add_on_replace: add the control if not already added * * Replaces the given control. If the given control does not exist * and the add_on_replace flag is set, the control is added. If the * control exists, it is destroyed first. * * It frees automatically the control which cannot be added or replaced. * * Return: Zero if successful, or a negative error code on failure. */ int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, bool add_on_replace) { struct snd_ctl_elem_id id; unsigned int count; unsigned int idx; struct snd_kcontrol *old; int ret; if (!kcontrol) return -EINVAL; if (snd_BUG_ON(!card || !kcontrol->info)) { ret = -EINVAL; goto error; } id = kcontrol->id; down_write(&card->controls_rwsem); old = snd_ctl_find_id(card, &id); if (!old) { if (add_on_replace) goto add; up_write(&card->controls_rwsem); ret = -EINVAL; goto error; } ret = snd_ctl_remove(card, old); if (ret < 0) { up_write(&card->controls_rwsem); goto error; } add: if (snd_ctl_find_hole(card, kcontrol->count) < 0) { up_write(&card->controls_rwsem); ret = -ENOMEM; goto error; } list_add_tail(&kcontrol->list, &card->controls); card->controls_count += kcontrol->count; kcontrol->id.numid = card->last_numid + 1; card->last_numid += kcontrol->count; id = kcontrol->id; count = kcontrol->count; up_write(&card->controls_rwsem); for (idx = 0; idx < count; idx++, id.index++, id.numid++) snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id); return 0; error: snd_ctl_free_one(kcontrol); return ret; } EXPORT_SYMBOL(snd_ctl_replace); /** * 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). * * Return: 0 if successful, or a negative error code on failure. */ int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol) { struct snd_ctl_elem_id id; unsigned int idx; if (snd_BUG_ON(!card || !kcontrol)) 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; } EXPORT_SYMBOL(snd_ctl_remove); /** * 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. * * Return: 0 if successful, or a negative error code on failure. */ int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id) { struct snd_kcontrol *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; } EXPORT_SYMBOL(snd_ctl_remove_id); /** * snd_ctl_remove_user_ctl - remove and release the unlocked user control * @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. * * Return: 0 if successful, or a negative error code on failure. */ static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file, struct snd_ctl_elem_id *id) { struct snd_card *card = file->card; struct snd_kcontrol *kctl; int idx, ret; down_write(&card->controls_rwsem); kctl = snd_ctl_find_id(card, id); if (kctl == NULL) { ret = -ENOENT; goto error; } if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) { ret = -EINVAL; goto error; } for (idx = 0; idx < kctl->count; idx++) if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) { ret = -EBUSY; goto error; } ret = snd_ctl_remove(card, kctl); if (ret < 0) goto error; card->user_ctl_count--; error: up_write(&card->controls_rwsem); return ret; } /** * snd_ctl_activate_id - activate/inactivate the control of the given id * @card: the card instance * @id: the control id to activate/inactivate * @active: non-zero to activate * * Finds the control instance with the given id, and activate or * inactivate the control together with notification, if changed. * The given ID data is filled with full information. * * Return: 0 if unchanged, 1 if changed, or a negative error code on failure. */ int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id, int active) { struct snd_kcontrol *kctl; struct snd_kcontrol_volatile *vd; unsigned int index_offset; int ret; down_write(&card->controls_rwsem); kctl = snd_ctl_find_id(card, id); if (kctl == NULL) { ret = -ENOENT; goto unlock; } index_offset = snd_ctl_get_ioff(kctl, id); vd = &kctl->vd[index_offset]; ret = 0; if (active) { if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)) goto unlock; vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE; } else { if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE) goto unlock; vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE; } snd_ctl_build_ioff(id, kctl, index_offset); ret = 1; unlock: up_write(&card->controls_rwsem); if (ret > 0) snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id); return ret; } EXPORT_SYMBOL_GPL(snd_ctl_activate_id); /** * 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. * * Return: Zero if successful, or a negative error code on failure. */ int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id, struct snd_ctl_elem_id *dst_id) { struct snd_kcontrol *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; } EXPORT_SYMBOL(snd_ctl_rename_id); /** * 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. * * The caller must down card->controls_rwsem before calling this function * (if the race condition can happen). * * Return: The pointer of the instance if found, or %NULL if not. * */ struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid) { struct snd_kcontrol *kctl; if (snd_BUG_ON(!card || !numid)) return NULL; list_for_each_entry(kctl, &card->controls, list) { if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid) return kctl; } return NULL; } EXPORT_SYMBOL(snd_ctl_find_numid); /** * 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. * * The caller must down card->controls_rwsem before calling this function * (if the race condition can happen). * * Return: The pointer of the instance if found, or %NULL if not. * */ struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card, struct snd_ctl_elem_id *id) { struct snd_kcontrol *kctl; if (snd_BUG_ON(!card || !id)) return NULL; if (id->numid != 0) return snd_ctl_find_numid(card, id->numid); list_for_each_entry(kctl, &card->controls, 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; } EXPORT_SYMBOL(snd_ctl_find_id); static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl, unsigned int cmd, void __user *arg) { struct snd_ctl_card_info *info; info = kzalloc(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(struct snd_ctl_card_info))) { kfree(info); return -EFAULT; } kfree(info); return 0; } static int snd_ctl_elem_list(struct snd_card *card, struct snd_ctl_elem_list __user *_list) { struct list_head *plist; struct snd_ctl_elem_list list; struct snd_kcontrol *kctl; struct snd_ctl_elem_id *dst, *id; unsigned int offset, space, jidx; if (copy_from_user(&list, _list, sizeof(list))) return -EFAULT; offset = list.offset; space = list.space; /* try limit maximum space */ if (space > 16384) return -ENOMEM; if (space > 0) { /* allocate temporary buffer for atomic operation */ dst = vmalloc(space * sizeof(struct snd_ctl_elem_id)); 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(struct snd_ctl_elem_id))) { 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(struct snd_ctl_file *ctl, struct snd_ctl_elem_info *info) { struct snd_card *card = ctl->card; struct snd_kcontrol *kctl; struct snd_kcontrol_volatile *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_BUG_ON(info->access); 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 = pid_vnr(vd->owner->pid); } else { info->owner = -1; } } up_read(&card->controls_rwsem); return result; } static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl, struct snd_ctl_elem_info __user *_info) { struct snd_ctl_elem_info info; int result; if (copy_from_user(&info, _info, sizeof(info))) return -EFAULT; snd_power_lock(ctl->card); result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0); if (result >= 0) result = snd_ctl_elem_info(ctl, &info); snd_power_unlock(ctl->card); if (result >= 0) if (copy_to_user(_info, &info, sizeof(info))) return -EFAULT; return result; } static int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control) { struct snd_kcontrol *kctl; struct snd_kcontrol_volatile *vd; unsigned int index_offset; int result; 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]; 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(struct snd_card *card, struct snd_ctl_elem_value __user *_control) { struct snd_ctl_elem_value *control; int result; control = memdup_user(_control, sizeof(*control)); if (IS_ERR(control)) return PTR_ERR(control); snd_power_lock(card); result = snd_power_wait(card, SNDRV_CTL_POWER_D0); if (result >= 0) result = snd_ctl_elem_read(card, control); snd_power_unlock(card); if (result >= 0) if (copy_to_user(_control, control, sizeof(*control))) result = -EFAULT; kfree(control); return result; } static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file, struct snd_ctl_elem_value *control) { struct snd_kcontrol *kctl; struct snd_kcontrol_volatile *vd; unsigned int index_offset; int result; 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]; if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL || (file && vd->owner && vd->owner != file)) { result = -EPERM; } else { snd_ctl_build_ioff(&control->id, kctl, index_offset); result = kctl->put(kctl, control); } if (result > 0) { struct snd_ctl_elem_id id = control->id; up_read(&card->controls_rwsem); snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id); return 0; } } up_read(&card->controls_rwsem); return result; } static int snd_ctl_elem_write_user(struct snd_ctl_file *file, struct snd_ctl_elem_value __user *_control) { struct snd_ctl_elem_value *control; struct snd_card *card; int result; control = memdup_user(_control, sizeof(*control)); if (IS_ERR(control)) return PTR_ERR(control); card = file->card; snd_power_lock(card); result = snd_power_wait(card, SNDRV_CTL_POWER_D0); if (result >= 0) result = snd_ctl_elem_write(card, file, control); snd_power_unlock(card); if (result >= 0) if (copy_to_user(_control, control, sizeof(*control))) result = -EFAULT; kfree(control); return result; } static int snd_ctl_elem_lock(struct snd_ctl_file *file, struct snd_ctl_elem_id __user *_id) { struct snd_card *card = file->card; struct snd_ctl_elem_id id; struct snd_kcontrol *kctl; struct snd_kcontrol_volatile *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; result = 0; } } up_write(&card->controls_rwsem); return result; } static int snd_ctl_elem_unlock(struct snd_ctl_file *file, struct snd_ctl_elem_id __user *_id) { struct snd_card *card = file->card; struct snd_ctl_elem_id id; struct snd_kcontrol *kctl; struct snd_kcontrol_volatile *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; result = 0; } } up_write(&card->controls_rwsem); return result; } struct user_element { struct snd_ctl_elem_info info; struct snd_card *card; char *elem_data; /* element data */ unsigned long elem_data_size; /* size of element data in bytes */ void *tlv_data; /* TLV data */ unsigned long tlv_data_size; /* TLV data size */ void *priv_data; /* private data (like strings for enumerated type) */ }; static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo) { struct user_element *ue = kcontrol->private_data; unsigned int offset; offset = snd_ctl_get_ioff(kcontrol, &uinfo->id); *uinfo = ue->info; snd_ctl_build_ioff(&uinfo->id, kcontrol, offset); return 0; } static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo) { struct user_element *ue = kcontrol->private_data; const char *names; unsigned int item; unsigned int offset; item = uinfo->value.enumerated.item; offset = snd_ctl_get_ioff(kcontrol, &uinfo->id); *uinfo = ue->info; snd_ctl_build_ioff(&uinfo->id, kcontrol, offset); item = min(item, uinfo->value.enumerated.items - 1); uinfo->value.enumerated.item = item; names = ue->priv_data; for (; item > 0; --item) names += strlen(names) + 1; strcpy(uinfo->value.enumerated.name, names); return 0; } static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { struct user_element *ue = kcontrol->private_data; unsigned int size = ue->elem_data_size; char *src = ue->elem_data + snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size; mutex_lock(&ue->card->user_ctl_lock); memcpy(&ucontrol->value, src, size); mutex_unlock(&ue->card->user_ctl_lock); return 0; } static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol) { int change; struct user_element *ue = kcontrol->private_data; unsigned int size = ue->elem_data_size; char *dst = ue->elem_data + snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size; mutex_lock(&ue->card->user_ctl_lock); change = memcmp(&ucontrol->value, dst, size) != 0; if (change) memcpy(dst, &ucontrol->value, size); mutex_unlock(&ue->card->user_ctl_lock); return change; } static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol, int op_flag, unsigned int size, unsigned int __user *tlv) { struct user_element *ue = kcontrol->private_data; int change = 0; void *new_data; if (op_flag == SNDRV_CTL_TLV_OP_WRITE) { if (size > 1024 * 128) /* sane value */ return -EINVAL; new_data = memdup_user(tlv, size); if (IS_ERR(new_data)) return PTR_ERR(new_data); mutex_lock(&ue->card->user_ctl_lock); change = ue->tlv_data_size != size; if (!change) change = memcmp(ue->tlv_data, new_data, size); kfree(ue->tlv_data); ue->tlv_data = new_data; ue->tlv_data_size = size; mutex_unlock(&ue->card->user_ctl_lock); } else { int ret = 0; mutex_lock(&ue->card->user_ctl_lock); if (!ue->tlv_data_size || !ue->tlv_data) { ret = -ENXIO; goto err_unlock; } if (size < ue->tlv_data_size) { ret = -ENOSPC; goto err_unlock; } if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size)) ret = -EFAULT; err_unlock: mutex_unlock(&ue->card->user_ctl_lock); if (ret) return ret; } return change; } static int snd_ctl_elem_init_enum_names(struct user_element *ue) { char *names, *p; size_t buf_len, name_len; unsigned int i; const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr; if (ue->info.value.enumerated.names_length > 64 * 1024) return -EINVAL; names = memdup_user((const void __user *)user_ptrval, ue->info.value.enumerated.names_length); if (IS_ERR(names)) return PTR_ERR(names); /* check that there are enough valid names */ buf_len = ue->info.value.enumerated.names_length; p = names; for (i = 0; i < ue->info.value.enumerated.items; ++i) { name_len = strnlen(p, buf_len); if (name_len == 0 || name_len >= 64 || name_len == buf_len) { kfree(names); return -EINVAL; } p += name_len + 1; buf_len -= name_len + 1; } ue->priv_data = names; ue->info.value.enumerated.names_ptr = 0; return 0; } static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol) { struct user_element *ue = kcontrol->private_data; kfree(ue->tlv_data); kfree(ue->priv_data); kfree(ue); } static int snd_ctl_elem_add(struct snd_ctl_file *file, struct snd_ctl_elem_info *info, int replace) { /* The capacity of struct snd_ctl_elem_value.value.*/ static const unsigned int value_sizes[] = { [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long), [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long), [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int), [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char), [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958), [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long), }; static const unsigned int max_value_counts[] = { [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128, [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128, [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128, [SNDRV_CTL_ELEM_TYPE_BYTES] = 512, [SNDRV_CTL_ELEM_TYPE_IEC958] = 1, [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64, }; struct snd_card *card = file->card; struct snd_kcontrol *kctl; unsigned int count; unsigned int access; long private_size; struct user_element *ue; unsigned int offset; int err; if (!*info->id.name) return -EINVAL; if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name)) return -EINVAL; /* Delete a control to replace them if needed. */ if (replace) { info->id.numid = 0; err = snd_ctl_remove_user_ctl(file, &info->id); if (err) return err; } /* * The number of userspace controls are counted control by control, * not element by element. */ if (card->user_ctl_count + 1 > MAX_USER_CONTROLS) return -ENOMEM; /* Check the number of elements for this userspace control. */ count = info->owner; if (count == 0) count = 1; /* Arrange access permissions if needed. */ access = info->access; if (access == 0) access = SNDRV_CTL_ELEM_ACCESS_READWRITE; access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE | SNDRV_CTL_ELEM_ACCESS_INACTIVE | SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE); if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK; access |= SNDRV_CTL_ELEM_ACCESS_USER; /* * Check information and calculate the size of data specific to * this userspace control. */ if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN || info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64) return -EINVAL; if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED && info->value.enumerated.items == 0) return -EINVAL; if (info->count < 1 || info->count > max_value_counts[info->type]) return -EINVAL; private_size = value_sizes[info->type] * info->count; /* * Keep memory object for this userspace control. After passing this * code block, the instance should be freed by snd_ctl_free_one(). * * Note that these elements in this control are locked. */ err = snd_ctl_new(&kctl, count, access, file); if (err < 0) return err; memcpy(&kctl->id, &info->id, sizeof(kctl->id)); kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count, GFP_KERNEL); if (kctl->private_data == NULL) { kfree(kctl); return -ENOMEM; } kctl->private_free = snd_ctl_elem_user_free; /* Set private data for this userspace control. */ ue = (struct user_element *)kctl->private_data; ue->card = card; ue->info = *info; ue->info.access = 0; ue->elem_data = (char *)ue + sizeof(*ue); ue->elem_data_size = private_size; if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) { err = snd_ctl_elem_init_enum_names(ue); if (err < 0) { snd_ctl_free_one(kctl); return err; } } /* Set callback functions. */ if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) kctl->info = snd_ctl_elem_user_enum_info; else 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; if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) kctl->tlv.c = snd_ctl_elem_user_tlv; /* This function manage to free the instance on failure. */ err = snd_ctl_add(card, kctl); if (err < 0) return err; offset = snd_ctl_get_ioff(kctl, &info->id); snd_ctl_build_ioff(&info->id, kctl, offset); /* * Here we cannot fill any field for the number of elements added by * this operation because there're no specific fields. The usage of * 'owner' field for this purpose may cause any bugs to userspace * applications because the field originally means PID of a process * which locks the element. */ down_write(&card->controls_rwsem); card->user_ctl_count++; up_write(&card->controls_rwsem); return 0; } static int snd_ctl_elem_add_user(struct snd_ctl_file *file, struct snd_ctl_elem_info __user *_info, int replace) { struct snd_ctl_elem_info info; int err; if (copy_from_user(&info, _info, sizeof(info))) return -EFAULT; err = snd_ctl_elem_add(file, &info, replace); if (err < 0) return err; if (copy_to_user(_info, &info, sizeof(info))) { snd_ctl_remove_user_ctl(file, &info.id); return -EFAULT; } return 0; } static int snd_ctl_elem_remove(struct snd_ctl_file *file, struct snd_ctl_elem_id __user *_id) { struct snd_ctl_elem_id id; if (copy_from_user(&id, _id, sizeof(id))) return -EFAULT; return snd_ctl_remove_user_ctl(file, &id); } static int snd_ctl_subscribe_events(struct snd_ctl_file *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; } static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file, struct snd_ctl_tlv __user *_tlv, int op_flag) { struct snd_card *card = file->card; struct snd_ctl_tlv tlv; struct snd_kcontrol *kctl; struct snd_kcontrol_volatile *vd; unsigned int len; int err = 0; if (copy_from_user(&tlv, _tlv, sizeof(tlv))) return -EFAULT; if (tlv.length < sizeof(unsigned int) * 2) return -EINVAL; down_read(&card->controls_rwsem); kctl = snd_ctl_find_numid(card, tlv.numid); if (kctl == NULL) { err = -ENOENT; goto __kctl_end; } if (kctl->tlv.p == NULL) { err = -ENXIO; goto __kctl_end; } vd = &kctl->vd[tlv.numid - kctl->id.numid]; if ((op_flag == SNDRV_CTL_TLV_OP_READ && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) || (op_flag == SNDRV_CTL_TLV_OP_WRITE && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) || (op_flag == SNDRV_CTL_TLV_OP_CMD && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) { err = -ENXIO; goto __kctl_end; } if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) { if (vd->owner != NULL && vd->owner != file) { err = -EPERM; goto __kctl_end; } err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv); if (err > 0) { struct snd_ctl_elem_id id = kctl->id; up_read(&card->controls_rwsem); snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id); return 0; } } else { if (op_flag != SNDRV_CTL_TLV_OP_READ) { err = -ENXIO; goto __kctl_end; } len = kctl->tlv.p[1] + 2 * sizeof(unsigned int); if (tlv.length < len) { err = -ENOMEM; goto __kctl_end; } if (copy_to_user(_tlv->tlv, kctl->tlv.p, len)) err = -EFAULT; } __kctl_end: up_read(&card->controls_rwsem); return err; } static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct snd_ctl_file *ctl; struct snd_card *card; struct snd_kctl_ioctl *p; void __user *argp = (void __user *)arg; int __user *ip = argp; int err; ctl = file->private_data; card = ctl->card; if (snd_BUG_ON(!card)) 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(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(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_TLV_READ: return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ); case SNDRV_CTL_IOCTL_TLV_WRITE: return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE); case SNDRV_CTL_IOCTL_TLV_COMMAND: return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD); case SNDRV_CTL_IOCTL_POWER: return -ENOPROTOOPT; 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_entry(p, &snd_control_ioctls, list) { err = p->fioctl(card, ctl, cmd, arg); if (err != -ENOIOCTLCMD) { up_read(&snd_ioctl_rwsem); return err; } } up_read(&snd_ioctl_rwsem); dev_dbg(card->dev, "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) { struct snd_ctl_file *ctl; int err = 0; ssize_t result = 0; ctl = file->private_data; if (snd_BUG_ON(!ctl || !ctl->card)) return -ENXIO; if (!ctl->subscribed) return -EBADFD; if (count < sizeof(struct snd_ctl_event)) return -EINVAL; spin_lock_irq(&ctl->read_lock); while (count >= sizeof(struct snd_ctl_event)) { struct snd_ctl_event ev; struct snd_kctl_event *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 (ctl->card->shutdown) return -ENODEV; if (signal_pending(current)) return -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(struct snd_ctl_event))) { err = -EFAULT; goto __end; } spin_lock_irq(&ctl->read_lock); buffer += sizeof(struct snd_ctl_event); count -= sizeof(struct snd_ctl_event); result += sizeof(struct snd_ctl_event); } __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; struct snd_ctl_file *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) { struct snd_kctl_ioctl *pn; pn = kzalloc(sizeof(struct snd_kctl_ioctl), 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; } /** * snd_ctl_register_ioctl - register the device-specific control-ioctls * @fcn: ioctl callback function * * called from each device manager like pcm.c, hwdep.c, etc. */ int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn) { return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls); } EXPORT_SYMBOL(snd_ctl_register_ioctl); #ifdef CONFIG_COMPAT /** * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat * control-ioctls * @fcn: ioctl callback function */ int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn) { return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls); } EXPORT_SYMBOL(snd_ctl_register_ioctl_compat); #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 snd_kctl_ioctl *p; if (snd_BUG_ON(!fcn)) return -EINVAL; down_write(&snd_ioctl_rwsem); list_for_each_entry(p, lists, 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; } /** * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls * @fcn: ioctl callback function to unregister */ int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn) { return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls); } EXPORT_SYMBOL(snd_ctl_unregister_ioctl); #ifdef CONFIG_COMPAT /** * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit * control-ioctls * @fcn: ioctl callback function to unregister */ int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn) { return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls); } EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat); #endif static int snd_ctl_fasync(int fd, struct file * file, int on) { struct snd_ctl_file *ctl; ctl = file->private_data; return fasync_helper(fd, file, on, &ctl->fasync); } /* return the preferred subdevice number if already assigned; * otherwise return -1 */ int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type) { struct snd_ctl_file *kctl; int subdevice = -1; read_lock(&card->ctl_files_rwlock); list_for_each_entry(kctl, &card->ctl_files, list) { if (kctl->pid == task_pid(current)) { subdevice = kctl->preferred_subdevice[type]; if (subdevice != -1) break; } } read_unlock(&card->ctl_files_rwlock); return subdevice; } EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice); /* * ioctl32 compat */ #ifdef CONFIG_COMPAT #include "control_compat.c" #else #define snd_ctl_ioctl_compat NULL #endif /* * INIT PART */ static const struct file_operations snd_ctl_f_ops = { .owner = THIS_MODULE, .read = snd_ctl_read, .open = snd_ctl_open, .release = snd_ctl_release, .llseek = no_llseek, .poll = snd_ctl_poll, .unlocked_ioctl = snd_ctl_ioctl, .compat_ioctl = snd_ctl_ioctl_compat, .fasync = snd_ctl_fasync, }; /* * registration of the control device */ static int snd_ctl_dev_register(struct snd_device *device) { struct snd_card *card = device->device_data; return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1, &snd_ctl_f_ops, card, &card->ctl_dev); } /* * disconnection of the control device */ static int snd_ctl_dev_disconnect(struct snd_device *device) { struct snd_card *card = device->device_data; struct snd_ctl_file *ctl; read_lock(&card->ctl_files_rwlock); list_for_each_entry(ctl, &card->ctl_files, list) { wake_up(&ctl->change_sleep); kill_fasync(&ctl->fasync, SIGIO, POLL_ERR); } read_unlock(&card->ctl_files_rwlock); return snd_unregister_device(&card->ctl_dev); } /* * free all controls */ static int snd_ctl_dev_free(struct snd_device *device) { struct snd_card *card = device->device_data; struct snd_kcontrol *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); put_device(&card->ctl_dev); return 0; } /* * create control core: * called from init.c */ int snd_ctl_create(struct snd_card *card) { static struct snd_device_ops ops = { .dev_free = snd_ctl_dev_free, .dev_register = snd_ctl_dev_register, .dev_disconnect = snd_ctl_dev_disconnect, }; int err; if (snd_BUG_ON(!card)) return -ENXIO; if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS)) return -ENXIO; snd_device_initialize(&card->ctl_dev, card); dev_set_name(&card->ctl_dev, "controlC%d", card->number); err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops); if (err < 0) put_device(&card->ctl_dev); return err; } /* * Frequently used control callbacks/helpers */ /** * snd_ctl_boolean_mono_info - Helper function for a standard boolean info * callback with a mono channel * @kcontrol: the kcontrol instance * @uinfo: info to store * * This is a function that can be used as info callback for a standard * boolean control with a single mono channel. */ int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo) { uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN; uinfo->count = 1; uinfo->value.integer.min = 0; uinfo->value.integer.max = 1; return 0; } EXPORT_SYMBOL(snd_ctl_boolean_mono_info); /** * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info * callback with stereo two channels * @kcontrol: the kcontrol instance * @uinfo: info to store * * This is a function that can be used as info callback for a standard * boolean control with stereo two channels. */ int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo) { uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN; uinfo->count = 2; uinfo->value.integer.min = 0; uinfo->value.integer.max = 1; return 0; } EXPORT_SYMBOL(snd_ctl_boolean_stereo_info); /** * snd_ctl_enum_info - fills the info structure for an enumerated control * @info: the structure to be filled * @channels: the number of the control's channels; often one * @items: the number of control values; also the size of @names * @names: an array containing the names of all control values * * Sets all required fields in @info to their appropriate values. * If the control's accessibility is not the default (readable and writable), * the caller has to fill @info->access. * * Return: Zero. */ int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels, unsigned int items, const char *const names[]) { info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED; info->count = channels; info->value.enumerated.items = items; if (!items) return 0; if (info->value.enumerated.item >= items) info->value.enumerated.item = items - 1; WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name), "ALSA: too long item name '%s'\n", names[info->value.enumerated.item]); strlcpy(info->value.enumerated.name, names[info->value.enumerated.item], sizeof(info->value.enumerated.name)); return 0; } EXPORT_SYMBOL(snd_ctl_enum_info);