refactor project structure

libasound.c started to become quite large, split the big chunks into
pcm.c and mixer.c

12 files changed, 471 insertions, 459 deletions

diff --git a/Makefile b/Makefile
index 0786c76..42b6414 100644
--- a/Makefile
+++ b/Makefile
@@ -26,7 +26,7 @@ libasound.so.2.0.0: private override CPPFLAGS += -DBYTE_ORDER=__BYTE_ORDER -DLIT
 libasound.so.2.0.0: private override CFLAGS += -Wno-unused-parameter -Wno-deprecated-declarations
 libasound.so.2.0.0: private override LDFLAGS += -Wl,--version-script=libasound.map -Wl,-soname,libasound.so.2
 libasound.so.2.0.0: private override LDLIBS += -lsndio
-libasound.so.2.0.0: libasound.c dsp/dsp.c libasound.map stubs.h symversioning-hell.h
+libasound.so.2.0.0: src/libasound.c src/pcm.c src/mixer.c src/util/dsp.c src/util/dsp.h src/util/sysex.h src/util/defs.h src/util/util.h src/stubs.h src/symversioning-hell.h libasound.map
 	$(LINK.c) -shared $(filter %.c,$^) $(LDLIBS) -o $@
 
 libasound.so.2: libasound.so.2.0.0
diff --git a/gen-stubs.bash b/gen-stubs.bash
index cd5a6cb..0b9886b 100644
--- a/gen-stubs.bash
+++ b/gen-stubs.bash
@@ -76,5 +76,5 @@ preprocess()
 
 cat include/alsa/*.h | preprocess | match | tr -d ';' | while read -r fun; do
    name="$(fun_name_for "$fun")"
-   grep -Fqs "$name(" libasound.c || printf '%s { WARNX1("stub"); %s }\n' "$fun" "$(return_for "$fun" "$name")"
+   grep -Fqs "$name(" src/{libasound,pcm,mixer}.c || printf '%s { WARNX1("stub"); %s }\n' "$fun" "$(return_for "$fun" "$name")"
 done
diff --git a/src/libasound.c b/src/libasound.c
new file mode 100644
index 0000000..b43ae95
--- /dev/null
+++ b/src/libasound.c
@@ -0,0 +1,173 @@
+#include <alsa/asoundlib.h>
+#include <alsa/pcm.h>
+#include <alsa/pcm_plugin.h>
+#include <alsa/pcm_extplug.h>
+#include <alsa/pcm_ioplug.h>
+#include <alsa/control_external.h>
+#include <alsa/mixer_abst.h>
+#include <alsa/use-case.h>
+#include <alsa/topology.h>
+
+#include "util/util.h"
+#include "stubs.h"
+#include "symversioning-hell.h"
+
+struct _snd_config { char noop; } s_snd_config;
+struct _snd_config *snd_config = &s_snd_config;
+
+const char*
+snd_asoundlib_version(void)
+{
+   return "1.1.7";
+}
+
+const char*
+snd_strerror(int errnum)
+{
+   // Do not bother implementing this, just WARN/ERR directly in this lib
+   // Letting applications show useful error messages never works out
+   return "^";
+}
+
+snd_lib_error_handler_t snd_lib_error;
+
+int snd_lib_error_set_handler(snd_lib_error_handler_t handler)
+{
+   snd_lib_error = handler;
+   return 0;
+}
+
+int
+snd_card_load(int card)
+{
+   return 0;
+}
+
+int
+snd_card_next(int *card)
+{
+   if (card) {
+      *card = (*card == -1 ? 0 : -1);
+      return 0;
+   }
+
+   return -1;
+}
+
+int
+snd_card_get_index(const char *name)
+{
+   if (!strcmp(name, "default"))
+      return 0;
+
+   return -1;
+}
+
+int
+snd_card_get_name(int card, char **name)
+{
+   if (name) *name = "default";
+   return 0;
+}
+
+int snd_card_get_longname(int card, char **name)
+{
+   if (name) *name = "default";
+   return 0;
+}
+
+struct device_name_hint { char *name, *ioid; };
+
+int
+snd_device_name_hint(int card, const char *iface, void ***hints)
+{
+   static struct device_name_hint defaults[] = { { .name = "default", .ioid = "Output" }, { .name = "capture", .ioid = "Input" } };
+   static struct device_name_hint *array[] = { &defaults[0], &defaults[1], NULL };
+   *hints = (void**)array;
+   return 0;
+}
+
+char*
+snd_device_name_get_hint(const void *hint, const char *id)
+{
+   const struct device_name_hint *shint = hint;
+
+   if (!strcmp(id, "NAME"))
+      return c_strdup(shint->name);
+   else if (!strcmp(id, "IOID"))
+      return c_strdup(shint->ioid);
+
+   return NULL;
+}
+
+int
+snd_device_name_free_hint(void **hints)
+{
+   return 0;
+}
+
+struct _snd_ctl {
+   char noop;
+};
+
+int
+snd_ctl_open(snd_ctl_t **ctl, const char *name, int mode)
+{
+   if (!(*ctl = calloc(1, sizeof(**ctl)))) {
+      WARNX1("calloc");
+      return -1;
+   }
+
+   return 0;
+}
+
+int
+snd_ctl_close(snd_ctl_t *ctl)
+{
+   free(ctl);
+   return 0;
+}
+
+struct _snd_ctl_card_info {
+   const char *name;
+};
+
+size_t
+snd_ctl_card_info_sizeof(void)
+{
+   return sizeof(snd_ctl_card_info_t);
+}
+
+int
+snd_ctl_card_info_malloc(snd_ctl_card_info_t **ptr)
+{
+   if (!(*ptr = calloc(1, sizeof(**ptr))))
+      return -1;
+
+   return 0;
+}
+
+void
+snd_ctl_card_info_free(snd_ctl_card_info_t *obj)
+{
+   free(obj);
+}
+
+int
+snd_ctl_card_info(snd_ctl_t *ctl, snd_ctl_card_info_t *info)
+{
+   info->name = "sndio";
+   return 0;
+}
+
+const char*
+snd_ctl_card_info_get_name(const snd_ctl_card_info_t *obj)
+{
+   return obj->name;
+}
+
+const char*
+snd_ctl_card_info_get_mixername(const snd_ctl_card_info_t *obj)
+{
+   return obj->name;
+}
diff --git a/src/mixer.c b/src/mixer.c
new file mode 100644
index 0000000..317f12c
--- /dev/null
+++ b/src/mixer.c
@@ -0,0 +1,264 @@
+#include <alsa/asoundlib.h>
+#include <sndio.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include "util/sysex.h"
+#include "util/util.h"
+
+struct _snd_mixer_elem {
+   snd_mixer_elem_t *next;
+   char name[SYSEX_NAMELEN];
+   unsigned int index, vol;
+};
+
+struct _snd_mixer {
+   struct mio_hdl *hdl;
+   snd_mixer_elem_t *controls;
+};
+
+#define MIXER_MAX_CHANNELS 16
+
+static bool
+onsysex(unsigned char *buf, unsigned len, snd_mixer_elem_t controls[MIXER_MAX_CHANNELS + 1])
+{
+   if (len < SYSEX_SIZE(empty))
+      return false;
+
+   union {
+      struct sysex x;
+      unsigned char buf[sizeof(struct sysex)];
+   } u;
+
+   memcpy(u.buf, buf, len);
+
+   if (u.x.type == SYSEX_TYPE_RT && u.x.id0 == SYSEX_CONTROL && u.x.id1 == SYSEX_MASTER) {
+      if (len == SYSEX_SIZE(master)) {
+         controls[0].vol = u.x.u.master.coarse;
+         snprintf(controls[0].name, sizeof(controls[0].name), "master");
+      }
+      return false;
+   }
+
+   if (u.x.type != SYSEX_TYPE_EDU || u.x.id0 != SYSEX_AUCAT)
+      return false;
+
+   switch (u.x.id1) {
+      case SYSEX_AUCAT_MIXINFO: {
+         unsigned cn = u.x.u.mixinfo.chan;
+         if (cn >= MIXER_MAX_CHANNELS || !memchr(u.x.u.mixinfo.name, '\0', SYSEX_NAMELEN))
+            return false;
+
+         snprintf(controls[cn + 1].name, sizeof(controls[cn + 1].name), "%s", u.x.u.mixinfo.name);
+         break;
+      }
+
+      case SYSEX_AUCAT_DUMPEND:
+         return true;
+   }
+
+   return false;
+}
+
+static void
+oncommon(unsigned char *buf, unsigned len, snd_mixer_elem_t controls[MIXER_MAX_CHANNELS + 1])
+{
+#define MIDI_CMDMASK 0xf0
+#define MIDI_CTL 0xb0
+#define MIDI_CTLVOL 7
+   if ((buf[0] & MIDI_CMDMASK) != MIDI_CTL || buf[1] != MIDI_CTLVOL)
+      return;
+
+#define MIDI_CHANMASK 0x0f
+   unsigned cn = (buf[0] & MIDI_CHANMASK);
+   if (cn >= MIXER_MAX_CHANNELS)
+      return;
+
+   controls[cn + 1].vol = buf[2];
+}
+
+static void
+get_controls(snd_mixer_t *mixer)
+{
+   const unsigned char dumpreq[] = {
+      SYSEX_START,
+      SYSEX_TYPE_EDU,
+      0,
+      SYSEX_AUCAT,
+      SYSEX_AUCAT_DUMPREQ,
+      SYSEX_END,
+   };
+
+   static snd_mixer_elem_t controls[MIXER_MAX_CHANNELS + 1];
+   memset(controls, 0, sizeof(controls));
+
+   unsigned char buf[0x100];
+   mio_write(mixer->hdl, dumpreq, sizeof(dumpreq));
+   for (int ready = 0; !ready;) {
+      size_t size;
+      if (!(size = mio_read(mixer->hdl, buf, sizeof(buf)))) {
+         WARNX1("mio_read failed");
+         return;
+      }
+
+      static unsigned voice_len[] = { 3, 3, 3, 3, 2, 2, 3 };
+      static unsigned common_len[] = { 0, 2, 3, 2, 0, 0, 1, 1 };
+
+      unsigned char mmsg[0x100];
+      unsigned int mst = 0, midx = 0, mlen = 0;
+      for (unsigned char *p = buf; size > 0; --size, ++p) {
+         if (*p >= 0xf8) {
+            /* clock events */
+         } else if (*p >= 0xf0) {
+            if (mst == SYSEX_START && *p == SYSEX_END && midx < sizeof(mmsg)) {
+               mmsg[midx++] = *p;
+               ready = onsysex(mmsg, midx, controls);
+               continue;
+            }
+
+            mmsg[0] = *p;
+            mlen = common_len[*p & 7];
+            mst = *p;
+            midx = 1;
+         } else if (*p >= 0x80) {
+            mmsg[0] = *p;
+            mlen = voice_len[(*p >> 4) & 7];
+            mst = *p;
+            midx = 1;
+         } else if (mst) {
+            if (midx == sizeof(mmsg))
+               continue;
+
+            if (midx == 0)
+               mmsg[midx++] = mst;
+
+            mmsg[midx++] = *p;
+
+            if (midx == mlen) {
+               oncommon(mmsg, midx, controls);
+               midx = 0;
+            }
+         }
+      }
+   }
+
+   snd_mixer_elem_t **tail = &mixer->controls;
+   for (size_t i = 0; i < ARRAY_SIZE(controls); ++i) {
+      if (!controls[i].name[0])
+         continue;
+
+      *tail = &controls[i];
+      tail = &(*tail)->next;
+   }
+}
+
+int
+snd_mixer_open(snd_mixer_t **mixer, int mode)
+{
+   if (!(*mixer = calloc(1, sizeof(**mixer)))) {
+      WARNX1("calloc");
+      return -1;
+   }
+
+   if (!((*mixer)->hdl = mio_open("snd/0", MIO_OUT | MIO_IN, 0))) {
+      WARNX1("mio_open failed");
+      goto fail;
+   }
+
+   get_controls(*mixer);
+   return 0;
+
+fail:
+   free(*mixer);
+   return -1;
+}
+
+int
+snd_mixer_close(snd_mixer_t *mixer)
+{
+   mio_close(mixer->hdl);
+   free(mixer);
+   return 0;
+}
+
+struct _snd_mixer_selem_id {
+   char noop;
+};
+
+int
+snd_mixer_selem_id_malloc(snd_mixer_selem_id_t **ptr)
+{
+   if (!(*ptr = calloc(1, sizeof(**ptr))))
+      return -1;
+
+   return 0;
+}
+
+void
+snd_mixer_selem_id_free(snd_mixer_selem_id_t *obj)
+{
+   free(obj);
+}
+
+snd_mixer_elem_t*
+snd_mixer_first_elem(snd_mixer_t *mixer)
+{
+   return mixer->controls;
+}
+
+snd_mixer_elem_t*
+snd_mixer_elem_next(snd_mixer_elem_t *elem)
+{
+   return elem->next;
+}
+
+const char*
+snd_mixer_selem_get_name(snd_mixer_elem_t *elem)
+{
+   return elem->name;
+}
+
+int
+snd_mixer_selem_get_playback_volume(snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long *value)
+{
+   if (value) *value = ((float)elem->vol / (float)0x7f) * 100;
+   return 0;
+}
+
+int
+snd_mixer_selem_get_playback_dB(snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long *value)
+{
+   if (value) *value = (long)elem->vol - 0x7f;
+   return 0;
+}
+
+int
+snd_mixer_selem_get_playback_dB_range(snd_mixer_elem_t *elem, long *min, long *max)
+{
+   if (max) *max = 0;
+   if (min) *min = -127;
+   return 0;
+}
+
+int
+snd_mixer_selem_has_playback_volume(snd_mixer_elem_t *elem)
+{
+   return true;
+}
+
+int
+snd_mixer_selem_has_playback_volume_joined(snd_mixer_elem_t *elem)
+{
+   return true;
+}
+
+int
+snd_mixer_selem_has_playback_switch(snd_mixer_elem_t *elem)
+{
+   return true;
+}
+
+int
+snd_mixer_selem_has_playback_switch_joined(snd_mixer_elem_t *elem)
+{
+   return true;
+}
diff --git a/libasound.c b/src/pcm.c
index c39f4b6..ad77c06 100644
--- a/libasound.c
+++ b/src/pcm.c
@@ -1,138 +1,10 @@
 #include <alsa/asoundlib.h>
-#include <alsa/pcm.h>
-#include <alsa/pcm_plugin.h>
-#include <alsa/pcm_extplug.h>
-#include <alsa/pcm_ioplug.h>
-#include <alsa/control_external.h>
-#include <alsa/mixer_abst.h>
-#include <alsa/use-case.h>
-#include <alsa/topology.h>
-
 #include <sndio.h>
+#include <poll.h>
 #include <stdbool.h>
 #include <assert.h>
-#include <err.h>
-#include <poll.h>
-
-#include "dsp/dsp.h"
-#include "sysex.h"
-
-#define WARN1(x) do { warn("asound: %s %s", __func__, x); } while (0)
-#define WARN(x, ...) do { warn("asound: %s " x, __func__, ##__VA_ARGS__); } while (0)
-#define WARNX1(x) do { warnx("asound: %s %s", __func__, x); } while (0)
-#define WARNX(x, ...) do { warnx("asound: %s " x, __func__, ##__VA_ARGS__); } while (0)
-#define ERRX1(x, y) do { errx(x, "asound: %s %s", __func__, y); } while (0)
-#define ERRX(x, y, ...) do { errx(x, "asound: %s " y, __func__, ##__VA_ARGS__); } while (0)
-#define ERR(x, y, ...) do { err(x, "asound: %s " y, __func__, ##__VA_ARGS__); } while (0)
-
-#include "stubs.h"
-
-#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
-
-const char*
-snd_asoundlib_version(void)
-{
-   return "1.1.7";
-}
-
-const char*
-snd_strerror(int errnum)
-{
-   // Do not bother implementing this, just WARN/ERR directly in this lib
-   // Letting applications show useful error messages never works out
-   return "^";
-}
-
-snd_lib_error_handler_t snd_lib_error;
-
-int snd_lib_error_set_handler(snd_lib_error_handler_t handler)
-{
-   snd_lib_error = handler;
-   return 0;
-}
-
-struct _snd_config { char noop; } s_snd_config;
-struct _snd_config *snd_config = &s_snd_config;
-
-int
-snd_card_load(int card)
-{
-   return 0;
-}
-
-int
-snd_card_next(int *card)
-{
-   if (card) {
-      *card = (*card == -1 ? 0 : -1);
-      return 0;
-   }
-   return -1;
-}
-
-int
-snd_card_get_index(const char *name)
-{
-   if (!strcmp(name, "default"))
-      return 0;
-   return -1;
-}
-
-int
-snd_card_get_name(int card, char **name)
-{
-   if (name) *name = "default";
-   return 0;
-}
-
-int snd_card_get_longname(int card, char **name)
-{
-   if (name) *name = "default";
-   return 0;
-}
-
-struct _snd_pcm_hint { char *name, *ioid; };
-
-int
-snd_device_name_hint(int card, const char *iface, void ***hints)
-{
-   static struct _snd_pcm_hint defaults[] = { { .name = "default", .ioid = "Output" }, { .name = "capture", .ioid = "Input" } };
-   static struct _snd_pcm_hint *array[] = { &defaults[0], &defaults[1], NULL };
-   *hints = (void**)array;
-   return 0;
-}
-
-static char*
-c_strdup(const char *str)
-{
-   size_t len = strlen(str);
-
-   char *copy;
-   if (!(copy = calloc(1, len + 1)))
-      return NULL;
-
-   memcpy(copy, str, len);
-   return copy;
-}
-
-char*
-snd_device_name_get_hint(const void *hint, const char *id)
-{
-   const struct _snd_pcm_hint *shint = hint;
-
-   if (!strcmp(id, "NAME"))
-      return c_strdup(shint->name);
-   else if (!strcmp(id, "IOID"))
-      return c_strdup(shint->ioid);
-
-   return NULL;
-}
-
-int
-snd_device_name_free_hint(void **hints)
-{
-   return 0;
-}
+#include "util/dsp.h"
+#include "util/util.h"
 
 struct _snd_pcm_hw_params {
    struct sio_cap cap;
@@ -1036,329 +908,3 @@ snd_pcm_get_chmap(snd_pcm_t *pcm)
 
    return map;
 }
-
-struct _snd_ctl {
-   char noop;
-};
-
-int
-snd_ctl_open(snd_ctl_t **ctl, const char *name, int mode)
-{
-   if (!(*ctl = calloc(1, sizeof(**ctl)))) {
-      WARNX1("calloc");
-      return -1;
-   }
-
-   return 0;
-}
-
-int
-snd_ctl_close(snd_ctl_t *ctl)
-{
-   free(ctl);
-   return 0;
-}
-
-struct _snd_ctl_card_info {
-   const char *name;
-};
-
-size_t
-snd_ctl_card_info_sizeof(void)
-{
-   return sizeof(snd_ctl_card_info_t);
-}
-
-int
-snd_ctl_card_info_malloc(snd_ctl_card_info_t **ptr)
-{
-   if (!(*ptr = calloc(1, sizeof(**ptr))))
-      return -1;
-
-   return 0;
-}
-
-void
-snd_ctl_card_info_free(snd_ctl_card_info_t *obj)
-{
-   free(obj);
-}
-
-int
-snd_ctl_card_info(snd_ctl_t *ctl, snd_ctl_card_info_t *info)
-{
-   info->name = "sndio";
-   return 0;
-}
-
-const char*
-snd_ctl_card_info_get_name(const snd_ctl_card_info_t *obj)
-{
-   return obj->name;
-}
-
-const char*
-snd_ctl_card_info_get_mixername(const snd_ctl_card_info_t *obj)
-{
-   return obj->name;
-}
-
-struct _snd_mixer_elem {
-   snd_mixer_elem_t *next;
-   char name[SYSEX_NAMELEN];
-   unsigned int index, vol;
-};
-
-struct _snd_mixer {
-   struct mio_hdl *hdl;
-   snd_mixer_elem_t *controls;
-};
-
-#define MIXER_MAX_CHANNELS 16
-
-static bool
-onsysex(unsigned char *buf, unsigned len, snd_mixer_elem_t controls[MIXER_MAX_CHANNELS + 1])
-{
-   if (len < SYSEX_SIZE(empty))
-      return false;
-
-   union {
-      struct sysex x;
-      unsigned char buf[sizeof(struct sysex)];
-   } u;
-
-   memcpy(u.buf, buf, len);
-
-   if (u.x.type == SYSEX_TYPE_RT && u.x.id0 == SYSEX_CONTROL && u.x.id1 == SYSEX_MASTER) {
-      if (len == SYSEX_SIZE(master)) {
-         controls[0].vol = u.x.u.master.coarse;
-         snprintf(controls[0].name, sizeof(controls[0].name), "master");
-      }
-      return false;
-   }
-
-   if (u.x.type != SYSEX_TYPE_EDU || u.x.id0 != SYSEX_AUCAT)
-      return false;
-
-   switch (u.x.id1) {
-      case SYSEX_AUCAT_MIXINFO: {
-         unsigned cn = u.x.u.mixinfo.chan;
-         if (cn >= MIXER_MAX_CHANNELS || !memchr(u.x.u.mixinfo.name, '\0', SYSEX_NAMELEN))
-            return false;
-
-         snprintf(controls[cn + 1].name, sizeof(controls[cn + 1].name), "%s", u.x.u.mixinfo.name);
-         break;
-      }
-
-      case SYSEX_AUCAT_DUMPEND:
-         return true;
-   }
-
-   return false;
-}
-
-static void
-oncommon(unsigned char *buf, unsigned len, snd_mixer_elem_t controls[MIXER_MAX_CHANNELS + 1])
-{
-#define MIDI_CMDMASK 0xf0
-#define MIDI_CTL 0xb0
-#define MIDI_CTLVOL 7
-   if ((buf[0] & MIDI_CMDMASK) != MIDI_CTL || buf[1] != MIDI_CTLVOL)
-      return;
-
-#define MIDI_CHANMASK 0x0f
-   unsigned cn = (buf[0] & MIDI_CHANMASK);
-   if (cn >= MIXER_MAX_CHANNELS)
-      return;
-
-   controls[cn + 1].vol = buf[2];
-}
-
-static void
-get_controls(snd_mixer_t *mixer)
-{
-   const unsigned char dumpreq[] = {
-      SYSEX_START,
-      SYSEX_TYPE_EDU,
-      0,
-      SYSEX_AUCAT,
-      SYSEX_AUCAT_DUMPREQ,
-      SYSEX_END,
-   };
-
-   static snd_mixer_elem_t controls[MIXER_MAX_CHANNELS + 1];
-   memset(controls, 0, sizeof(controls));
-
-   unsigned char buf[0x100];
-   mio_write(mixer->hdl, dumpreq, sizeof(dumpreq));
-   for (int ready = 0; !ready;) {
-      size_t size;
-      if (!(size = mio_read(mixer->hdl, buf, sizeof(buf)))) {
-         WARNX1("mio_read failed");
-         return;
-      }
-
-      static unsigned voice_len[] = { 3, 3, 3, 3, 2, 2, 3 };
-      static unsigned common_len[] = { 0, 2, 3, 2, 0, 0, 1, 1 };
-
-      unsigned char mmsg[0x100];
-      unsigned int mst = 0, midx = 0, mlen = 0;
-      for (unsigned char *p = buf; size > 0; --size, ++p) {
-         if (*p >= 0xf8) {
-            /* clock events */
-         } else if (*p >= 0xf0) {
-            if (mst == SYSEX_START && *p == SYSEX_END && midx < sizeof(mmsg)) {
-               mmsg[midx++] = *p;
-               ready = onsysex(mmsg, midx, controls);
-               continue;
-            }
-
-            mmsg[0] = *p;
-            mlen = common_len[*p & 7];
-            mst = *p;
-            midx = 1;
-         } else if (*p >= 0x80) {
-            mmsg[0] = *p;
-            mlen = voice_len[(*p >> 4) & 7];
-            mst = *p;
-            midx = 1;
-         } else if (mst) {
-            if (midx == sizeof(mmsg))
-               continue;
-
-            if (midx == 0)
-               mmsg[midx++] = mst;
-
-            mmsg[midx++] = *p;
-
-            if (midx == mlen) {
-               oncommon(mmsg, midx, controls);
-               midx = 0;
-            }
-         }
-      }
-   }
-
-   snd_mixer_elem_t **tail = &mixer->controls;
-   for (size_t i = 0; i < ARRAY_SIZE(controls); ++i) {
-      if (!controls[i].name[0])
-         continue;
-
-      *tail = &controls[i];
-      tail = &(*tail)->next;
-   }
-}
-
-int
-snd_mixer_open(snd_mixer_t **mixer, int mode)
-{
-   if (!(*mixer = calloc(1, sizeof(**mixer)))) {
-      WARNX1("calloc");
-      return -1;
-   }
-
-   if (!((*mixer)->hdl = mio_open("snd/0", MIO_OUT | MIO_IN, 0))) {
-      WARNX1("mio_open failed");
-      goto fail;
-   }
-
-   get_controls(*mixer);
-   return 0;
-
-fail:
-   free(*mixer);
-   return -1;
-}
-
-int
-snd_mixer_close(snd_mixer_t *mixer)
-{
-   mio_close(mixer->hdl);
-   free(mixer);
-   return 0;
-}
-
-struct _snd_mixer_selem_id {
-   char noop;
-};
-
-int
-snd_mixer_selem_id_malloc(snd_mixer_selem_id_t **ptr)
-{
-   if (!(*ptr = calloc(1, sizeof(**ptr))))
-      return -1;
-
-   return 0;
-}
-
-void
-snd_mixer_selem_id_free(snd_mixer_selem_id_t *obj)
-{
-   free(obj);
-}
-
-snd_mixer_elem_t*
-snd_mixer_first_elem(snd_mixer_t *mixer)
-{
-   return mixer->controls;
-}
-
-snd_mixer_elem_t*
-snd_mixer_elem_next(snd_mixer_elem_t *elem)
-{
-   return elem->next;
-}
-
-const char*
-snd_mixer_selem_get_name(snd_mixer_elem_t *elem)
-{
-   return elem->name;
-}
-
-int
-snd_mixer_selem_get_playback_volume(snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long *value)
-{
-   if (value) *value = ((float)elem->vol / (float)0x7f) * 100;
-   return 0;
-}
-
-int
-snd_mixer_selem_get_playback_dB(snd_mixer_elem_t *elem, snd_mixer_selem_channel_id_t channel, long *value)
-{
-   if (value) *value = (long)elem->vol - 0x7f;
-   return 0;
-}
-
-int
-snd_mixer_selem_get_playback_dB_range(snd_mixer_elem_t *elem, long *min, long *max)
-{
-   if (max) *max = 0;
-   if (min) *min = -127;
-   return 0;
-}
-
-int
-snd_mixer_selem_has_playback_volume(snd_mixer_elem_t *elem)
-{
-   return true;
-}
-
-int
-snd_mixer_selem_has_playback_volume_joined(snd_mixer_elem_t *elem)
-{
-   return true;
-}
-
-int
-snd_mixer_selem_has_playback_switch(snd_mixer_elem_t *elem)
-{
-   return true;
-}
-
-int
-snd_mixer_selem_has_playback_switch_joined(snd_mixer_elem_t *elem)
-{
-   return true;
-}
-
-#include "symversioning-hell.h"
diff --git a/stubs.h b/src/stubs.h
index f52e19e..f52e19e 100644
--- a/stubs.h
+++ b/src/stubs.h
diff --git a/symversioning-hell.h b/src/symversioning-hell.h
index f3e9b35..f3e9b35 100644
--- a/symversioning-hell.h
+++ b/src/symversioning-hell.h
diff --git a/dsp/defs.h b/src/util/defs.h
index 6cfc877..6cfc877 100644
--- a/dsp/defs.h
+++ b/src/util/defs.h
diff --git a/dsp/dsp.c b/src/util/dsp.c
index 62510b9..62510b9 100644
--- a/dsp/dsp.c
+++ b/src/util/dsp.c
diff --git a/dsp/dsp.h b/src/util/dsp.h
index d057d37..d057d37 100644
--- a/dsp/dsp.h
+++ b/src/util/dsp.h
diff --git a/sysex.h b/src/util/sysex.h
index 245cd2a..245cd2a 100644
--- a/sysex.h
+++ b/src/util/sysex.h
diff --git a/src/util/util.h b/src/util/util.h
new file mode 100644
index 0000000..9e118c2
--- /dev/null
+++ b/src/util/util.h
@@ -0,0 +1,29 @@
+#pragma once
+
+#include <stdlib.h>
+#include <string.h>
+#include <stddef.h>
+#include <err.h>
+
+#define WARN1(x) do { warn("asound: %s %s", __func__, x); } while (0)
+#define WARN(x, ...) do { warn("asound: %s " x, __func__, ##__VA_ARGS__); } while (0)
+#define WARNX1(x) do { warnx("asound: %s %s", __func__, x); } while (0)
+#define WARNX(x, ...) do { warnx("asound: %s " x, __func__, ##__VA_ARGS__); } while (0)
+#define ERRX1(x, y) do { errx(x, "asound: %s %s", __func__, y); } while (0)
+#define ERRX(x, y, ...) do { errx(x, "asound: %s " y, __func__, ##__VA_ARGS__); } while (0)
+#define ERR(x, y, ...) do { err(x, "asound: %s " y, __func__, ##__VA_ARGS__); } while (0)
+
+#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
+
+static inline char*
+c_strdup(const char *str)
+{
+   size_t len = strlen(str);
+
+   char *copy;
+   if (!(copy = calloc(1, len + 1)))
+      return NULL;
+
+   memcpy(copy, str, len);
+   return copy;
+}