Add opl library main header and stub functions.

Subversion-branch: /branches/opl-branch
Subversion-revision: 1455

3 files changed, 123 insertions, 0 deletions

diff --git a/opl/Makefile.am b/opl/Makefile.am
index 8fd2303e..65f8b2de 100644
--- a/opl/Makefile.am
+++ b/opl/Makefile.am
@@ -4,5 +4,6 @@ AM_CFLAGS=@SDLMIXER_CFLAGS@
 noinst_LIBRARIES=libopl.a
 
 libopl_a_SOURCES =                                \
+        opl.c               opl.h                 \
         fmopl.c
 
diff --git a/opl/opl.c b/opl/opl.c
new file mode 100644
index 00000000..d3dfc23b
--- /dev/null
+++ b/opl/opl.c
@@ -0,0 +1,49 @@
+// Emacs style mode select   -*- C++ -*- 
+//-----------------------------------------------------------------------------
+//
+// Copyright(C) 2009 Simon Howard
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+// 02111-1307, USA.
+//
+// DESCRIPTION:
+//     OPL interface.
+//
+//-----------------------------------------------------------------------------
+
+#include "opl.h"
+
+int OPL_Init(unsigned int port_base)
+{
+    // TODO
+    return 1;
+}
+
+void OPL_Shutdown(void)
+{
+    // TODO
+}
+
+void OPL_WritePort(opl_port_t port, unsigned int value)
+{
+    // TODO
+}
+
+unsigned int OPL_ReadPort(opl_port_t port)
+{
+    // TODO
+    return 0;
+}
+
diff --git a/opl/opl.h b/opl/opl.h
new file mode 100644
index 00000000..62b507f7
--- /dev/null
+++ b/opl/opl.h
@@ -0,0 +1,73 @@
+// Emacs style mode select   -*- C++ -*- 
+//-----------------------------------------------------------------------------
+//
+// Copyright(C) 2009 Simon Howard
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+// 02111-1307, USA.
+//
+// DESCRIPTION:
+//     OPL interface.
+//
+//-----------------------------------------------------------------------------
+
+
+#ifndef OPL_OPL_H
+#define OPL_OPL_H
+
+typedef enum
+{
+    OPL_REGISTER_PORT = 0,
+    OPL_DATA_PORT = 1
+} opl_port_t;
+
+#define OPL_NUM_OPERATORS   21
+#define OPL_NUM_VOICES      9
+
+#define OPL_REG_TIMER1            0x02
+#define OPL_REG_TIMER2            0x03
+#define OPL_REG_TIMER_CTRL        0x04
+#define OPL_REG_FM_MODE           0x08
+
+// Operator registers (21 of each):
+
+#define OPL_REGS_TREMOLO          0x20
+#define OPL_REGS_LEVEL            0x40
+#define OPL_REGS_ATTACK           0x60
+#define OPL_REGS_SUSTAIN          0x80
+
+// Voice registers (9 of each):
+
+#define OPL_REGS_FREQ_1           0xA0
+#define OPL_REGS_FREQ_2           0xB0
+
+// Initialise the OPL subsystem.
+
+int OPL_Init(unsigned int port_base);
+
+// Shut down the OPL subsystem.
+
+void OPL_Shutdown(void);
+
+// Write to one of the OPL I/O ports:
+
+void OPL_WritePort(opl_port_t port, unsigned int value);
+
+// Read from one of the OPL I/O ports:
+
+unsigned int OPL_ReadPort(opl_port_t port);
+
+#endif
+