git.mutantstargoat.com Git - gbajam21/blob - src/dma.c

   1 #include "dma.h"
   2
   3 /* DMA Options */
   4 #define DMA_ENABLE                              0x80000000
   5 #define DMA_INT_ENABLE                  0x40000000
   6 #define DMA_TIMING_IMMED                0x00000000
   7 #define DMA_TIMING_VBLANK               0x10000000
   8 #define DMA_TIMING_HBLANK               0x20000000
   9 #define DMA_TIMING_DISPSYNC             0x30000000
  10 #define DMA_16                                  0x00000000
  11 #define DMA_32                                  0x04000000
  12 #define DMA_REPEAT                              0x02000000
  13 #define DMA_SRC_INC                             0x00000000
  14 #define DMA_SRC_DEC                             0x00800000
  15 #define DMA_SRC_FIX                             0x01000000
  16 #define DMA_DST_INC                             0x00000000
  17 #define DMA_DST_DEC                             0x00200000
  18 #define DMA_DST_FIX1                    0x00400000
  19 #define DMA_DST_RELOAD                  0x00600000
  20
  21 /* DMA Register Parts */
  22 #define DMA_SRC         0
  23 #define DMA_DST         1
  24 #define DMA_CTRL        2
  25
  26 static volatile uint32_t *reg_dma[4] = {(void*)0x040000b0, (void*)0x040000bc, (void*)0x040000c8, (void*)0x040000d4 };
  27
  28 /* --- perform a copy of words or halfwords using DMA --- */
  29
  30 void dma_copy32(int channel, void *dst, void *src, int words, unsigned int flags)
  31 {
  32         reg_dma[channel][DMA_SRC] = (uint32_t)src;
  33         reg_dma[channel][DMA_DST] = (uint32_t)dst;
  34         reg_dma[channel][DMA_CTRL] = words | flags | DMA_32 | DMA_ENABLE;
  35 }
  36
  37 void dma_copy16(int channel, void *dst, void *src, int halfwords, unsigned int flags)
  38 {
  39         reg_dma[channel][DMA_SRC] = (uint32_t)src;
  40         reg_dma[channel][DMA_DST] = (uint32_t)dst;
  41         reg_dma[channel][DMA_CTRL] = halfwords | flags | DMA_16 | DMA_ENABLE;
  42 }
  43
  44 /* --- fill a buffer with an ammount of words and halfwords using DMA --- */
  45
  46 static uint32_t fill[4];
  47
  48 void dma_fill32(int channel, void *dst, uint32_t val, int words)
  49 {
  50         fill[channel] = val;
  51         reg_dma[channel][DMA_SRC] = (uint32_t)(fill + channel);
  52         reg_dma[channel][DMA_DST] = (uint32_t)dst;
  53         reg_dma[channel][DMA_CTRL] = words | DMA_SRC_FIX | DMA_TIMING_IMMED | DMA_32 | DMA_ENABLE;
  54 }
  55
  56 void dma_fill16(int channel, void *dst, uint16_t val, int halfwords)
  57 {
  58         fill[channel] = val;
  59         reg_dma[channel][DMA_SRC] = (uint32_t)(fill + channel);
  60         reg_dma[channel][DMA_DST] = (uint32_t)dst;
  61         reg_dma[channel][DMA_CTRL] = halfwords | DMA_SRC_FIX | DMA_TIMING_IMMED | DMA_16 | DMA_ENABLE;
  62 }