fixed 8bit writes to vmem, unaligned data buffers, and started on

[gba_blender] / src / dma.c

diff --git a/src/dma.c b/src/dma.c
new file mode 100644 (file)
index 0000000..78b516f
--- /dev/null
+++ b/src/dma.c
@@ -0,0 +1,77 @@
+/*
+gbasys - a gameboy advance hardware abstraction library
+Copyright (C) 2004-2014  John Tsiombikas <nuclear@member.fsf.org>
+
+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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+#include "dma.h"
+
+/* DMA Options */
+#define DMA_ENABLE                             0x80000000
+#define DMA_INT_ENABLE                 0x40000000
+#define DMA_TIMING_IMMED               0x00000000
+#define DMA_TIMING_VBLANK              0x10000000
+#define DMA_TIMING_HBLANK              0x20000000
+#define DMA_TIMING_DISPSYNC            0x30000000
+#define DMA_16                                 0x00000000
+#define DMA_32                                 0x04000000
+#define DMA_REPEAT                             0x02000000
+#define DMA_SRC_INC                            0x00000000
+#define DMA_SRC_DEC                            0x00800000
+#define DMA_SRC_FIX                            0x01000000
+#define DMA_DST_INC                            0x00000000
+#define DMA_DST_DEC                            0x00200000
+#define DMA_DST_FIX1                   0x00400000
+#define DMA_DST_RELOAD                 0x00600000
+
+/* DMA Register Parts */
+#define DMA_SRC                0
+#define DMA_DST                1
+#define DMA_CTRL       2
+
+static volatile unsigned long *reg_dma[4] = {(void*)0x040000b0, (void*)0x040000bc, (void*)0x040000c8, (void*)0x040000d4 };
+
+/* --- perform a copy of words or halfwords using DMA --- */
+
+void dma_copy32(int channel, void *dst, void *src, int words)
+{
+       reg_dma[channel][DMA_SRC] = (unsigned long)src;
+       reg_dma[channel][DMA_DST] = (unsigned long)dst;
+       reg_dma[channel][DMA_CTRL] = words | DMA_TIMING_IMMED | DMA_32 | DMA_ENABLE;
+}
+
+void dma_copy16(int channel, void *dst, void *src, int halfwords)
+{
+       reg_dma[channel][DMA_SRC] = (unsigned long)src;
+       reg_dma[channel][DMA_DST] = (unsigned long)dst;
+       reg_dma[channel][DMA_CTRL] = halfwords | DMA_TIMING_IMMED | DMA_16 | DMA_ENABLE;
+}
+
+/* --- fill a buffer with an ammount of words and halfwords using DMA --- */
+
+void dma_fill32(int channel, void *dst, unsigned long val, int words)
+{
+       unsigned long valmem = val;
+       reg_dma[channel][DMA_SRC] = (unsigned long)&valmem;
+       reg_dma[channel][DMA_DST] = (unsigned long)dst;
+       reg_dma[channel][DMA_CTRL] = words | DMA_SRC_FIX | DMA_TIMING_IMMED | DMA_32 | DMA_ENABLE;
+}
+
+void dma_fill16(int channel, void *dst, unsigned short val, int halfwords)
+{
+       unsigned short valmem = val;
+       reg_dma[channel][DMA_SRC] = (unsigned long)&valmem;
+       reg_dma[channel][DMA_DST] = (unsigned long)dst;
+       reg_dma[channel][DMA_CTRL] = halfwords | DMA_SRC_FIX | DMA_TIMING_IMMED | DMA_16 | DMA_ENABLE;
+}