Add --disable-user-elem configure option

6 files changed, 70 insertions, 1 deletions

diff --git a/README b/README
index 39b7233..89907fa 100644
--- a/README
+++ b/README
@@ -96,6 +96,10 @@ disabled as default.  For enabling the floating-point math calculation
 used in dB <-> linear conversion for the mixer, pass --enable-float
 option as well.
 
+The support for user-space control elements is enabled as default
+to keep the compatibility with the older salsa-lib releases.  But now
+it can be disabled via --disable-user-elem configure option, too.
+
 The async handler support can be enabled via --enable-async option.
 It's disabled as default.
 
diff --git a/configure.ac b/configure.ac
index d56bc9c..8735957 100644
--- a/configure.ac
+++ b/configure.ac
@@ -81,6 +81,12 @@ AC_ARG_ENABLE(tlv,
   AS_HELP_STRING([--enable-tlv],
 	 	 [enable TLV (dB) support]),
   tlv="$enableval", tlv="no")
+
+AC_ARG_ENABLE(user-elem,
+  AS_HELP_STRING([--disable-user-elem],
+	 	 [disable user-space control element support]),
+  user_elem="$enableval", user_elem="yes")
+
 AC_ARG_ENABLE(async,
   AS_HELP_STRING([--enable-async],
 		 [enable async handler support]),
@@ -140,6 +146,7 @@ if test "$everything" = "yes"; then
   sndconf="yes"
   sndseq="yes"
   tlv="yes"
+  user_elem="yes"
   async="yes"
   libasound="yes"
   symfuncs="yes"
@@ -167,6 +174,13 @@ else
 fi
 AC_SUBST(SALSA_HAS_TLV_SUPPORT)
 
+if test "$user_elem" = "yes"; then
+  SALSA_HAS_USER_ELEM_SUPPORT=1
+else
+  SALSA_HAS_USER_ELEM_SUPPORT=0
+fi
+AC_SUBST(SALSA_HAS_USER_ELEM_SUPPORT)
+
 if test "$async" = "yes"; then
   SALSA_HAS_ASYNC_SUPPORT=1
 else
@@ -270,6 +284,7 @@ echo "  - Timer interface: $timer"
 echo "  - ALSA-config dummy interface: $sndconf"
 echo "  - ALSA-sequencer dummy interface: $sndseq"
 echo "  - TLV (dB) support: $tlv"
+echo "  - User-space control element support: $user_elem"
 echo "  - Async handler support: $async"
 echo "  - Make ABI-compatible libasound.so: $libasound"
 echo "  - Mark deprecated attribute: $markdeprecated"
diff --git a/src/control.c b/src/control.c
index ea12f54..2047438 100644
--- a/src/control.c
+++ b/src/control.c
@@ -104,7 +104,7 @@ int snd_ctl_close(snd_ctl_t *ctl)
 	return 0;
 }
 
-
+#if SALSA_HAS_USER_ELEM_SUPPORT
 /*
  * add/remove user-defined controls
  */
@@ -219,6 +219,7 @@ int snd_ctl_elem_add_enumerated(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
 	info.value.enumerated.names_length = len;
 	return snd_ctl_elem_add(ctl, &info);
 }
+#endif /* USER_ELEM_SUPPORT */
 
 #if SALSA_HAS_TLV_SUPPORT
 /*
diff --git a/src/ctl_func.h b/src/ctl_func.h
index 9cbe131..c9e8001 100644
--- a/src/ctl_func.h
+++ b/src/ctl_func.h
@@ -51,6 +51,7 @@ int snd_async_add_ctl_handler(snd_async_handler_t **handler, snd_ctl_t *ctl,
 			      void *private_data);
 #endif
 
+#if SALSA_HAS_USER_ELEM_SUPPORT
 int snd_ctl_elem_add_integer(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
 			     unsigned int count, long min, long max, long step);
 int snd_ctl_elem_add_integer64(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
@@ -62,6 +63,7 @@ int snd_ctl_elem_add_iec958(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id);
 int snd_ctl_elem_add_enumerated(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
 				unsigned int count, unsigned int items,
 				const char *const names[]);
+#endif
 
 #if SALSA_HAS_TLV_SUPPORT
 int snd_tlv_parse_dB_info(unsigned int *tlv,
diff --git a/src/ctl_macros.h b/src/ctl_macros.h
index 737cfd0..2bfd3a4 100644
--- a/src/ctl_macros.h
+++ b/src/ctl_macros.h
@@ -112,9 +112,13 @@ int snd_ctl_elem_info(snd_ctl_t *ctl, snd_ctl_elem_info_t *info)
 __SALSA_EXPORT_FUNC
 int snd_ctl_elem_add(snd_ctl_t *ctl, snd_ctl_elem_info_t *info)
 {
+#if SALSA_HAS_USER_ELEM_SUPPORT
 	if (ioctl(ctl->fd, SNDRV_CTL_IOCTL_ELEM_ADD, info) < 0)
 		return -errno;
 	return 0;
+#else
+	return -ENXIO;
+#endif
 }
 
 __SALSA_EXPORT_FUNC
@@ -1020,6 +1024,46 @@ int snd_ctl_convert_from_dB(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
 #endif /* !SALSA_HAS_TLV_SUPPORT */
 
 /*
+ */
+#if !SALSA_HAS_USER_ELEM_SUPPORT
+__SALSA_EXPORT_FUNC __SALSA_NOT_IMPLEMENTED
+int snd_ctl_elem_add_integer(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
+			     unsigned int count, long min, long max, long step)
+{
+	return -ENXIO;
+}
+
+__SALSA_EXPORT_FUNC __SALSA_NOT_IMPLEMENTED
+int snd_ctl_elem_add_integer64(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
+			       unsigned int count, long long min, long long max,
+			       long long step)
+{
+	return -ENXIO;
+}
+
+__SALSA_EXPORT_FUNC __SALSA_NOT_IMPLEMENTED
+int snd_ctl_elem_add_boolean(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
+			     unsigned int count)
+{
+	return -ENXIO;
+}
+
+__SALSA_EXPORT_FUNC __SALSA_NOT_IMPLEMENTED
+int snd_ctl_elem_add_iec958(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id)
+{
+	return -ENXIO;
+}
+
+__SALSA_EXPORT_FUNC __SALSA_NOT_IMPLEMENTED
+int snd_ctl_elem_add_enumerated(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
+				unsigned int count, unsigned int items,
+				const char *const names[])
+{
+	return -ENXIO;
+}
+#endif /* !SALSA_HAS_USER_ELEM_SUPPORT */
+
+/*
  * not implemented yet
  */
 
diff --git a/src/recipe.h.in b/src/recipe.h.in
index 9a99150..c444f13 100644
--- a/src/recipe.h.in
+++ b/src/recipe.h.in
@@ -7,6 +7,9 @@
 /* Build with async support */
 #define SALSA_HAS_ASYNC_SUPPORT	@SALSA_HAS_ASYNC_SUPPORT@
 
+/* Build with user-space control element support */
+#define SALSA_HAS_USER_ELEM_SUPPORT	@SALSA_HAS_USER_ELEM_SUPPORT@
+
 /* Build with dummy conf support */
 #define SALSA_HAS_DUMMY_CONF	@SALSA_HAS_DUMMY_CONF@