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-rw-r--r--plugins/alsa/alsa-tools-low.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/plugins/alsa/alsa-tools-low.c b/plugins/alsa/alsa-tools-low.c
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+++ b/plugins/alsa/alsa-tools-low.c
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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;
+ }
+}
+