mirrors/alsa-lib
1
0
Fork 0
mirror of https://github.com/alsa-project/alsa-lib.git synced 2025-10-29 05:40:25 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Add external control plugin SDK

Browse source 
Added external control plugin SDK.
This commit is contained in:
Takashi Iwai 2005-06-09 17:12:08 +00:00
parent 36f715c59a
commit 8a3d07022c
6 changed files with 652 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

3
include/Makefile.am
View file

@ -9,7 +9,8 @@ alsainclude_HEADERS = asoundlib.h asoundef.h \
hwdep.h control.h mixer.h mixer_abst.h \
seq_event.h seq.h seqmid.h seq_midi_event.h \
conv.h instr.h iatomic.h \
alisp.h pcm_external.h pcm_ioplug.h pcm_extplug.h
alisp.h pcm_external.h pcm_ioplug.h pcm_extplug.h \
control_external.h
noinst_HEADERS = sys.h search.h list.h aserver.h local.h alsa-symbols.h

4
include/control.h
View file

@ -171,7 +171,9 @@ typedef enum _snd_ctl_type {
/** Shared memory client CTL */
SND_CTL_TYPE_SHM,
/** INET client CTL (not yet implemented) */
SND_CTL_TYPE_INET
SND_CTL_TYPE_INET,
/** External control plugin */
SND_CTL_TYPE_EXT
} snd_ctl_type_t;
/** Non blocking mode (flag for open mode) \hideinitializer */

184
include/control_external.h Normal file
View file

@ -0,0 +1,184 @@
/**
* \file include/control_external.h
* \brief External control plugin SDK
* \author Takashi Iwai <tiwai@suse.de>
* \date 2005
*
* External control plugin SDK.
*/
/*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef __ALSA_CONTROL_EXTERNAL_H
#define __ALSA_CONTROL_EXTERNAL_H
#include "control.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* \defgroup CtlPlugin_SDK External control plugin SDK
* \{
*/
/**
* Define the object entry for external control plugins
*/
#define SND_CTL_PLUGIN_ENTRY(name) _snd_ctl_##name##_open
/**
* Define the symbols of the given control plugin with versions
*/
#define SND_CTL_PLUGIN_SYMBOL(name) SND_DLSYM_BUILD_VERSION(SND_CTL_PLUGIN_ENTRY(name), SND_CONTROL_DLSYM_VERSION);
/**
* Define the control plugin
*/
#define SND_CTL_PLUGIN_DEFINE_FUNC(plugin) \
int SND_CTL_PLUGIN_ENTRY(plugin) (snd_ctl_t **handlep, const char *name,\
snd_config_t *root, snd_config_t *conf, int mode)
/** External control plugin handle */
typedef struct snd_ctl_ext snd_ctl_ext_t;
/** Callback table of control ext */
typedef struct snd_ctl_ext_callback snd_ctl_ext_callback_t;
/** Key to access a control pointer */
typedef unsigned long snd_ctl_ext_key_t;
/*
* Protocol version
*/
#define SND_CTL_EXT_VERSION_MAJOR 1 /**< Protocol major version */
#define SND_CTL_EXT_VERSION_MINOR 0 /**< Protocol minor version */
#define SND_CTL_EXT_VERSION_TINY 0 /**< Protocol tiny version */
/**
* external plugin protocol version
*/
#define SND_CTL_EXT_VERSION ((SND_CTL_EXT_VERSION_MAJOR<<16) |\
(SND_CTL_EXT_VERSION_MINOR<<8) |\
(SND_CTL_EXT_VERSION_TINY))
/** Handle of control ext */
struct snd_ctl_ext {
/**
* protocol version; #SND_CTL_EXT_VERSION must be filled here
* before calling #snd_ctl_ext_create()
*/
unsigned int version;
/**
* Index of this card; must be filled before calling #snd_ctl_ext_create()
*/
int card_idx;
/**
* ID string of this card; must be filled before calling #snd_ctl_ext_create()
*/
char id[16];
/**
* Driver name of this card; must be filled before calling #snd_ctl_ext_create()
*/
char driver[16];
/**
* short name of this card; must be filled before calling #snd_ctl_ext_create()
*/
char name[32];
/**
* Long name of this card; must be filled before calling #snd_ctl_ext_create()
*/
char longname[80];
/**
* Mixer name of this card; must be filled before calling #snd_ctl_ext_create()
*/
char mixername[80];
/**
* poll descriptor
*/
int poll_fd;
/**
* callbacks of this plugin; must be filled before calling #snd_pcm_ioplug_create()
*/
const snd_ctl_ext_callback_t *callback;
/**
* private data, which can be used freely in the driver callbacks
*/
void *private_data;
/**
* control handle filled by #snd_ctl_ext_create()
*/
snd_ctl_t *handle;
int nonblock; /**< non-block mode; read-only */
int subscribed; /**< events subscribed; read-only */
};
/** Callback table of ext */
struct snd_ctl_ext_callback {
void (*close)(snd_ctl_ext_t *ext); /* opt */
void (*subscribe_events)(snd_ctl_ext_t *ext, int subscribe); /* opt */
int (*elem_count)(snd_ctl_ext_t *ext); /* req */
int (*elem_list)(snd_ctl_ext_t *ext, unsigned int offset, snd_ctl_elem_id_t *id); /* req */
snd_ctl_ext_key_t (*find_elem)(snd_ctl_ext_t *ext, const snd_ctl_elem_id_t *id); /* req */
void (*free_key)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key); /* opt */
int (*get_attribute)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key,
int *type, unsigned int *acc, unsigned int *count); /* req */
int (*get_integer_info)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key,
long *imin, long *imax, long *istep);
int (*get_integer64_info)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key,
int64_t *imin, int64_t *imax, int64_t *istep);
int (*get_enumerated_info)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int *items);
int (*get_enumerated_name)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int item,
char *name, size_t name_max_len);
int (*read_integer)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, long *value);
int (*read_integer64)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, int64_t *value);
int (*read_enumerated)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int *items);
int (*read_bytes)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned char *data,
size_t max_bytes);
int (*read_iec958)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, snd_aes_iec958_t *iec958);
int (*write_integer)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, long *value);
int (*write_integer64)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, int64_t *value);
int (*write_enumerated)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned int *items);
int (*write_bytes)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, unsigned char *data,
size_t max_bytes);
int (*write_iec958)(snd_ctl_ext_t *ext, snd_ctl_ext_key_t key, snd_aes_iec958_t *iec958);
int (*read_event)(snd_ctl_ext_t *ext, snd_ctl_elem_id_t *id, unsigned int *event_mask);
int (*poll_descriptors_count)(snd_ctl_ext_t *ext);
int (*poll_descriptors)(snd_ctl_ext_t *ext, struct pollfd *pfds, unsigned int space);
int (*poll_revents)(snd_ctl_ext_t *ext, struct pollfd *pfds, unsigned int nfds, unsigned short *revents);
};
enum snd_ctl_ext_access_t {
SND_CTL_EXT_ACCESS_READ = (1<<0),
SND_CTL_EXT_ACCESS_WRITE = (1<<1),
SND_CTL_EXT_ACCESS_READWRITE = (3<<0),
SND_CTL_EXT_ACCESS_VOLATILE = (1<<2),
SND_CTL_EXT_ACCESS_INACTIVE = (1<<8),
};
#define SND_CTL_EXT_KEY_NOT_FOUND (snd_ctl_ext_key_t)(-1)
int snd_ctl_ext_create(snd_ctl_ext_t *ext, const char *name, int mode);
int snd_ctl_ext_delete(snd_ctl_ext_t *ext);
/** \} */
#ifdef __cplusplus
}
#endif
#endif /* __ALSA_CONTROL_EXTERNAL_H */

3
src/Versions
View file

@ -254,4 +254,7 @@ ALSA_1.0.10 {
snd_mixer_selem_set_capture_dB_all;
snd_mixer_selem_compare;
snd_ctl_ext_create;
snd_ctl_ext_delete;
} ALSA_1.0.9;

2
src/control/Makefile.am
View file

@ -2,7 +2,7 @@ EXTRA_LTLIBRARIES = libcontrol.la
libcontrol_la_SOURCES = cards.c hcontrol.c \
control.c control_hw.c control_shm.c \
setup.c control_symbols.c
control_ext.c setup.c control_symbols.c
noinst_HEADERS = control_local.h

459
src/control/control_ext.c Normal file
View file

@ -0,0 +1,459 @@
/*
* Control Interface - External Control Plugin SDK
*
* Copyright (c) 2005 Takashi Iwai <tiwai@suse.de>
*
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "control_local.h"
#include "control_external.h"
static int snd_ctl_ext_close(snd_ctl_t *handle)
{
snd_ctl_ext_t *ext = handle->private_data;
if (ext->callback->close)
ext->callback->close(ext);
return 0;
}
static int snd_ctl_ext_nonblock(snd_ctl_t *handle, int nonblock)
{
snd_ctl_ext_t *ext = handle->private_data;
ext->nonblock = nonblock;
return 0;
}
static int snd_ctl_ext_async(snd_ctl_t *ctl ATTRIBUTE_UNUSED,
int sig ATTRIBUTE_UNUSED,
pid_t pid ATTRIBUTE_UNUSED)
{
return -ENOSYS;
}
static int snd_ctl_ext_subscribe_events(snd_ctl_t *handle, int subscribe)
{
snd_ctl_ext_t *ext = handle->private_data;
if (subscribe < 0)
return ext->subscribed;
ext->subscribed = !!subscribe;
if (ext->callback->subscribe_events)
ext->callback->subscribe_events(ext, subscribe);
return 0;
}
static int snd_ctl_ext_card_info(snd_ctl_t *handle, snd_ctl_card_info_t *info)
{
snd_ctl_ext_t *ext = handle->private_data;
memset(info, 0, sizeof(*info));
info->card = ext->card_idx;
memcpy(info->id, ext->id, sizeof(info->id));
memcpy(info->driver, ext->driver, sizeof(info->driver));
memcpy(info->name, ext->name, sizeof(info->name));
memcpy(info->longname, ext->longname, sizeof(info->longname));
memcpy(info->mixername, ext->mixername, sizeof(info->mixername));
return 0;
}
static int snd_ctl_ext_elem_list(snd_ctl_t *handle, snd_ctl_elem_list_t *list)
{
snd_ctl_ext_t *ext = handle->private_data;
int ret;
unsigned int i, offset;
snd_ctl_elem_id_t *ids;
list->count = ext->callback->elem_count(ext);
list->used = 0;
ids = list->pids;
offset = list->offset;
for (i = 0; i < list->space; i++) {
if (offset >= list->count)
break;
snd_ctl_elem_id_clear(ids);
ret = ext->callback->elem_list(ext, offset, ids);
if (ret < 0)
return ret;
list->used++;
offset++;
ids++;
}
return 0;
}
static int snd_ctl_ext_elem_info(snd_ctl_t *handle, snd_ctl_elem_info_t *info)
{
snd_ctl_ext_t *ext = handle->private_data;
snd_ctl_ext_key_t key;
int type, ret;
key = ext->callback->find_elem(ext, &info->id);
if (key == SND_CTL_EXT_KEY_NOT_FOUND)
return -ENOENT;
ret = ext->callback->get_attribute(ext, key, &type, &info->access, &info->count);
if (ret < 0)
goto err;
info->type = type;
ret = -EINVAL;
switch (info->type) {
case SND_CTL_ELEM_TYPE_BOOLEAN:
info->value.integer.min = 0;
info->value.integer.max = 1;
ret = 0;
break;
case SND_CTL_ELEM_TYPE_INTEGER:
if (! ext->callback->get_integer_info)
goto err;
ret = ext->callback->get_integer_info(ext, key, &info->value.integer.min,
&info->value.integer.max,
&info->value.integer.step);
break;
case SND_CTL_ELEM_TYPE_INTEGER64:
if (! ext->callback->get_integer64_info)
goto err;
ret = ext->callback->get_integer64_info(ext, key, &info->value.integer64.min,
&info->value.integer64.max,
&info->value.integer64.step);
break;
case SND_CTL_ELEM_TYPE_ENUMERATED:
if (! ext->callback->get_enumerated_info)
goto err;
ret = ext->callback->get_enumerated_info(ext, key, &info->value.enumerated.items);
ext->callback->get_enumerated_name(ext, key, info->value.enumerated.item,
info->value.enumerated.name,
sizeof(info->value.enumerated.name));
break;
default:
ret = 0;
break;
}
err:
if (ext->callback->free_key)
ext->callback->free_key(ext, key);
return ret;
}
static int snd_ctl_ext_elem_add(snd_ctl_t *handle ATTRIBUTE_UNUSED,
snd_ctl_elem_info_t *info ATTRIBUTE_UNUSED)
{
return -ENXIO;
}
static int snd_ctl_ext_elem_replace(snd_ctl_t *handle ATTRIBUTE_UNUSED,
snd_ctl_elem_info_t *info ATTRIBUTE_UNUSED)
{
return -ENXIO;
}
static int snd_ctl_ext_elem_remove(snd_ctl_t *handle ATTRIBUTE_UNUSED,
snd_ctl_elem_id_t *id ATTRIBUTE_UNUSED)
{
return -ENXIO;
}
static int snd_ctl_ext_elem_read(snd_ctl_t *handle, snd_ctl_elem_value_t *control)
{
snd_ctl_ext_t *ext = handle->private_data;
snd_ctl_ext_key_t key;
int type, ret;
unsigned int access, count;
key = ext->callback->find_elem(ext, &control->id);
if (key == SND_CTL_EXT_KEY_NOT_FOUND)
return -ENOENT;
ret = ext->callback->get_attribute(ext, key, &type, &access, &count);
if (ret < 0)
goto err;
ret = -EINVAL;
switch (type) {
case SND_CTL_ELEM_TYPE_BOOLEAN:
case SND_CTL_ELEM_TYPE_INTEGER:
if (! ext->callback->read_integer)
goto err;
ret = ext->callback->read_integer(ext, key, control->value.integer.value);
break;
case SND_CTL_ELEM_TYPE_INTEGER64:
if (! ext->callback->read_integer64)
goto err;
ret = ext->callback->read_integer64(ext, key, control->value.integer64.value);
break;
case SND_CTL_ELEM_TYPE_ENUMERATED:
if (! ext->callback->read_enumerated)
goto err;
ret = ext->callback->read_enumerated(ext, key, control->value.enumerated.item);
break;
case SND_CTL_ELEM_TYPE_BYTES:
if (! ext->callback->read_bytes)
goto err;
ret = ext->callback->read_bytes(ext, key, control->value.bytes.data,
sizeof(control->value.bytes.data));
break;
case SND_CTL_ELEM_TYPE_IEC958:
if (! ext->callback->read_iec958)
goto err;
ret = ext->callback->read_iec958(ext, key, (snd_aes_iec958_t *)&control->value.iec958);
break;
default:
break;
}
err:
if (ext->callback->free_key)
ext->callback->free_key(ext, key);
return ret;
}
static int snd_ctl_ext_elem_write(snd_ctl_t *handle, snd_ctl_elem_value_t *control)
{
snd_ctl_ext_t *ext = handle->private_data;
snd_ctl_ext_key_t key;
int type, ret;
unsigned int access, count;
key = ext->callback->find_elem(ext, &control->id);
if (key == SND_CTL_EXT_KEY_NOT_FOUND)
return -ENOENT;
ret = ext->callback->get_attribute(ext, key, &type, &access, &count);
if (ret < 0)
goto err;
ret = -EINVAL;
switch (type) {
case SND_CTL_ELEM_TYPE_BOOLEAN:
case SND_CTL_ELEM_TYPE_INTEGER:
if (! ext->callback->write_integer)
goto err;
ret = ext->callback->write_integer(ext, key, control->value.integer.value);
break;
case SND_CTL_ELEM_TYPE_INTEGER64:
if (! ext->callback->write_integer64)
goto err;
ret = ext->callback->write_integer64(ext, key, control->value.integer64.value);
break;
case SND_CTL_ELEM_TYPE_ENUMERATED:
if (! ext->callback->write_enumerated)
goto err;
ret = ext->callback->write_enumerated(ext, key, control->value.enumerated.item);
break;
case SND_CTL_ELEM_TYPE_BYTES:
if (! ext->callback->write_bytes)
goto err;
ret = ext->callback->write_bytes(ext, key, control->value.bytes.data,
sizeof(control->value.bytes.data));
break;
case SND_CTL_ELEM_TYPE_IEC958:
if (! ext->callback->write_iec958)
goto err;
ret = ext->callback->write_iec958(ext, key, (snd_aes_iec958_t *)&control->value.iec958);
break;
default:
break;
}
err:
if (ext->callback->free_key)
ext->callback->free_key(ext, key);
return ret;
}
static int snd_ctl_ext_elem_lock(snd_ctl_t *handle ATTRIBUTE_UNUSED,
snd_ctl_elem_id_t *id ATTRIBUTE_UNUSED)
{
return -ENXIO;
}
static int snd_ctl_ext_elem_unlock(snd_ctl_t *handle ATTRIBUTE_UNUSED,
snd_ctl_elem_id_t *id ATTRIBUTE_UNUSED)
{
return -ENXIO;
}
static int snd_ctl_ext_next_device(snd_ctl_t *handle ATTRIBUTE_UNUSED,
int *device ATTRIBUTE_UNUSED)
{
return -ENXIO;
}
static int snd_ctl_ext_prefer_subdevice(snd_ctl_t *handle ATTRIBUTE_UNUSED,
int subdev ATTRIBUTE_UNUSED)
{
return -ENXIO;
}
static int snd_ctl_ext_hwdep_info(snd_ctl_t *handle ATTRIBUTE_UNUSED,
snd_hwdep_info_t *info ATTRIBUTE_UNUSED)
{
return -ENXIO;
}
static int snd_ctl_ext_pcm_info(snd_ctl_t *handle ATTRIBUTE_UNUSED,
snd_pcm_info_t *info ATTRIBUTE_UNUSED)
{
return -ENXIO;
}
static int snd_ctl_ext_rawmidi_info(snd_ctl_t *handle ATTRIBUTE_UNUSED,
snd_rawmidi_info_t *info ATTRIBUTE_UNUSED)
{
return -ENXIO;
}
static int snd_ctl_ext_set_power_state(snd_ctl_t *handle ATTRIBUTE_UNUSED,
unsigned int state ATTRIBUTE_UNUSED)
{
return 0;
}
static int snd_ctl_ext_get_power_state(snd_ctl_t *handle ATTRIBUTE_UNUSED,
unsigned int *state ATTRIBUTE_UNUSED)
{
return 0;
}
static int snd_ctl_ext_read(snd_ctl_t *handle, snd_ctl_event_t *event)
{
snd_ctl_ext_t *ext = handle->private_data;
memset(event, 0, sizeof(*event));
return ext->callback->read_event(ext, &event->data.elem.id, &event->data.elem.mask);
}
static int snd_ctl_ext_poll_descriptors_count(snd_ctl_t *handle)
{
snd_ctl_ext_t *ext = handle->private_data;
if (ext->callback->poll_descriptors_count)
return ext->callback->poll_descriptors_count(ext);
if (ext->poll_fd >= 0)
return 1;
return 0;
}
static int snd_ctl_ext_poll_descriptors(snd_ctl_t *handle, struct pollfd *pfds, unsigned int space)
{
snd_ctl_ext_t *ext = handle->private_data;
if (ext->callback->poll_descriptors)
return ext->callback->poll_descriptors(ext, pfds, space);
if (ext->poll_fd < 0)
return 0;
if (space > 0) {
pfds->fd = ext->poll_fd;
pfds->events = POLLIN|POLLERR|POLLNVAL;
return 1;
}
return 0;
}
static int snd_ctl_ext_poll_revents(snd_ctl_t *handle, struct pollfd *pfds, unsigned int nfds, unsigned short *revents)
{
snd_ctl_ext_t *ext = handle->private_data;
if (ext->callback->poll_revents)
return ext->callback->poll_revents(ext, pfds, nfds, revents);
if (nfds == 1) {
*revents = pfds->revents;
return 0;
}
return -EINVAL;
}
static snd_ctl_ops_t snd_ctl_ext_ops = {
.close = snd_ctl_ext_close,
.nonblock = snd_ctl_ext_nonblock,
.async = snd_ctl_ext_async,
.subscribe_events = snd_ctl_ext_subscribe_events,
.card_info = snd_ctl_ext_card_info,
.element_list = snd_ctl_ext_elem_list,
.element_info = snd_ctl_ext_elem_info,
.element_add = snd_ctl_ext_elem_add,
.element_replace = snd_ctl_ext_elem_replace,
.element_remove = snd_ctl_ext_elem_remove,
.element_read = snd_ctl_ext_elem_read,
.element_write = snd_ctl_ext_elem_write,
.element_lock = snd_ctl_ext_elem_lock,
.element_unlock = snd_ctl_ext_elem_unlock,
.hwdep_next_device = snd_ctl_ext_next_device,
.hwdep_info = snd_ctl_ext_hwdep_info,
.pcm_next_device = snd_ctl_ext_next_device,
.pcm_info = snd_ctl_ext_pcm_info,
.pcm_prefer_subdevice = snd_ctl_ext_prefer_subdevice,
.rawmidi_next_device = snd_ctl_rawmidi_next_device,
.rawmidi_info = snd_ctl_ext_rawmidi_info,
.rawmidi_prefer_subdevice = snd_ctl_ext_prefer_subdevice,
.set_power_state = snd_ctl_ext_set_power_state,
.get_power_state = snd_ctl_ext_get_power_state,
.read = snd_ctl_ext_read,
.poll_descriptors_count = snd_ctl_ext_poll_descriptors_count,
.poll_descriptors = snd_ctl_ext_poll_descriptors,
.poll_revents = snd_ctl_ext_poll_revents,
};
/**
* \brief Create an external control plugin instance
* \param ext the plugin handle
* \param name name of control
* \param mode control open mode
* \return 0 if successful, or a negative error code
*
* Creates the external control instance.
*
*/
int snd_ctl_ext_create(snd_ctl_ext_t *ext, const char *name, int mode)
{
snd_ctl_t *ctl;
int err;
if (ext->version != SND_CTL_EXT_VERSION) {
SNDERR("ctl_ext: Plugin version mismatch\n");
return -ENXIO;
}
err = snd_ctl_new(&ctl, SND_CTL_TYPE_EXT, name);
if (err < 0)
return err;
ext->handle = ctl;
ctl->ops = &snd_ctl_ext_ops;
ctl->private_data = ext;
ctl->poll_fd = ext->poll_fd;
if (mode & SND_CTL_NONBLOCK)
ext->nonblock = 1;
return 0;
}
/**
* \brief Delete the external control plugin
* \param ext the plugin handle
* \return 0 if successful, or a negative error code
*/
int snd_ctl_ext_delete(snd_ctl_ext_t *ext)
{
return snd_ctl_close(ext->handle);
}