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/*
* Copyright (C) 2018 "IoT.bzh"
* Author Fulup Ar Foll <fulup@iot.bzh>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#define _GNU_SOURCE // needed for vasprintf
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include "alsa-softmixer.h"
// extracted IOCTLs from <alsa/asoundlib.h>
#define _IOR_HACKED(type,nr,size) _IOC(_IOC_READ,(type),(nr),size)
#define SNDRV_CTL_IOCTL_CARD_INFO(size) _IOR_HACKED('U', 0x01, size)
// Clone of AlsaLib snd_card_load2 static function
int AlsaCardInfoByPath (const char *devpath) {
int open_dev;
snd_ctl_card_info_t *cardinfo = alloca(snd_ctl_card_info_sizeof());
open_dev = open(devpath, O_RDONLY);
if (open_dev >= 0) {
int rc = ioctl(open_dev, SNDRV_CTL_IOCTL_CARD_INFO(snd_ctl_card_info_sizeof()), cardinfo);
if (rc < 0) {
int err = -errno;
close(open_dev);
return err;
}
close(open_dev);
int cardId = snd_ctl_card_info_get_card(cardinfo);
return cardId;
} else {
return -errno;
}
}
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