3 files changed, 93 insertions, 0 deletions
diff --git a/arm7/lib/include/SND_exChannel.h b/arm7/lib/include/SND_exChannel.h
index 976d2786..8450a629 100644
--- a/arm7/lib/include/SND_exChannel.h
+++ b/arm7/lib/include/SND_exChannel.h
@@ -3,9 +3,12 @@
 
 #include "nitro/types.h"
 
+#include "nitro/SND_main_shared.h"
+
 void SND_ExChannelInit(void);
 BOOL SND_IsChannelActive(s32 idx);
 void SND_UpdateExChannel(void);
 void SND_ExChannelMain(BOOL update);
+void SND_FreeExChannel(struct SNDExChannel *chn);
 
 #endif //GUARD_SND_EXCHANNEL_H
diff --git a/arm7/lib/include/SND_lockChannel.h b/arm7/lib/include/SND_lockChannel.h
new file mode 100644
index 00000000..ed7fd872
--- /dev/null
+++ b/arm7/lib/include/SND_lockChannel.h
@@ -0,0 +1,11 @@
+#ifndef GUARD_SND_LOCKCHANNEL_H
+#define GUARD_SND_LOCKCHANNEL_H
+
+#include "nitro/types.h"
+
+void SND_StopUnlockedChannel(u32 channelMask);
+void SND_LockChannel(u32 channelMask, u32 locked);
+void SND_UnlockChannel(u32 channelMask, u32 locked);
+u32 SND_GetLockedChannel(u32 locked);
+
+#endif //GUARD_SND_LOCKCHANNEL_H
diff --git a/arm7/lib/src/SND_lockChannel.c b/arm7/lib/src/SND_lockChannel.c
new file mode 100644
index 00000000..cecfd871
--- /dev/null
+++ b/arm7/lib/src/SND_lockChannel.c
@@ -0,0 +1,79 @@
+#include "SND_lockChannel.h"
+
+#include "SND_work.h"
+#include "SND_exChannel.h"
+#include "SND.h"
+
+// TODO make these vars static after merging this file with exChannel
+u32 sUnlockedChannelMask;
+u32 sLockedChannelMask;
+
+void SND_StopUnlockedChannel(u32 channelMask) {
+    struct SNDExChannel *chn;
+    
+    for (int i = 0; i < SND_CHANNEL_COUNT && channelMask != 0; i++, channelMask >>= 1) {
+        if ((channelMask & 1) == 0)
+            continue;
+        
+        chn = &SNDi_Work.channels[i];
+
+        if (sUnlockedChannelMask & (1 << i))
+            continue;
+
+        if (chn->callback)
+            chn->callback(chn, 0, chn->callbackUserData);
+
+        SND_StopChannel(i, 0);
+        chn->priority = 0;
+        SND_FreeExChannel(chn);
+        chn->flags.syncFlag = 0;
+        chn->flags.active = 0;
+    }
+}
+
+void SND_LockChannel(u32 channelMask, u32 locked) {
+    struct SNDExChannel *chn;
+    u32 j = channelMask;
+    int i = 0;
+
+    for (; i < SND_CHANNEL_COUNT && j != 0; i++, j >>= 1) {
+        if ((j & 1) == 0)
+            continue;
+
+        chn = &SNDi_Work.channels[i];
+
+        if (sUnlockedChannelMask & (1 << i))
+            continue;
+
+        if (chn->callback)
+            chn->callback(chn, 0, chn->callbackUserData);
+
+        SND_StopChannel(i, 0);
+        chn->priority = 0;
+        SND_FreeExChannel(chn);
+        chn->flags.syncFlag = 0;
+        chn->flags.active = 0;
+    }
+
+    if (locked & 1) {
+        sLockedChannelMask |= channelMask;
+    } else {
+        sUnlockedChannelMask |= channelMask;
+    }
+}
+
+void SND_UnlockChannel(u32 channelMask, u32 locked) {
+    if (locked & 1) {
+        sLockedChannelMask &= ~channelMask;
+    } else {
+        sUnlockedChannelMask &= ~channelMask;
+    }
+}
+
+u32 SND_GetLockedChannel(u32 locked) {
+    if (locked & 1) {
+        return sLockedChannelMask;
+    } else {
+        return sUnlockedChannelMask;
+    }
+}