1 files changed, 112 insertions, 0 deletions
diff --git a/src/mixer_hw.c b/src/mixer_hw.c
new file mode 100644
index 0000000..2e86dfa
--- /dev/null
+++ b/src/mixer_hw.c
@@ -0,0 +1,112 @@
+/* mixer_hw.c
+** Copyright (c) 2019, The Linux Foundation.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above
+**     copyright notice, this list of conditions and the following
+**     disclaimer in the documentation and/or other materials provided
+**     with the distribution.
+**   * Neither the name of The Linux Foundation nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+** ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+** BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+** BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+** OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+** IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <ctype.h>
+#include <poll.h>
+
+#include <sys/ioctl.h>
+
+#include <linux/ioctl.h>
+#include <sound/asound.h>
+
+#include "mixer_io.h"
+
+/** Store the hardware (kernel interface) mixer data */
+struct mixer_hw_data {
+    /* Card number for the mixer */
+    unsigned int card;
+    /* File descriptor of the mixer device node */
+    int fd;
+};
+
+static void mixer_hw_close(void *data)
+{
+    struct mixer_hw_data *hw_data = data;
+
+    if (!hw_data)
+        return;
+
+    if (hw_data->fd >= 0)
+        close(hw_data->fd);
+
+    hw_data->fd = -1;
+    free(hw_data);
+    hw_data = NULL;
+}
+
+static int mixer_hw_ioctl(void *data, unsigned int cmd, ...)
+{
+    struct mixer_hw_data *hw_data = data;
+    va_list ap;
+    void *arg;
+
+    va_start(ap, cmd);
+    arg = va_arg(ap, void *);
+    va_end(ap);
+
+    return ioctl(hw_data->fd, cmd, arg);
+}
+
+static const struct mixer_ops mixer_hw_ops = {
+    .close = mixer_hw_close,
+    .ioctl = mixer_hw_ioctl,
+};
+
+int mixer_hw_open(unsigned int card, void **data,
+                  const struct mixer_ops **ops)
+{
+    struct mixer_hw_data *hw_data;
+    int fd;
+    char fn[256];
+
+    snprintf(fn, sizeof(fn), "/dev/snd/controlC%u", card);
+    fd = open(fn, O_RDWR);
+    if (fd < 0)
+        return fd;
+
+    hw_data = calloc(1, sizeof(*hw_data));
+    if (!hw_data)
+        return -1;
+
+    hw_data->card = card;
+    hw_data->fd = fd;
+    *data = hw_data;
+    *ops = &mixer_hw_ops;
+
+    return fd;
+}