git.sesse.net Git - pistorm/blob - platforms/amiga/cdtv-dmac.c

   1 #include <stdio.h>
   2 #include <stdint.h>
   3 #include <stdlib.h>
   4 #include "config_file/config_file.h"
   5
   6 uint8_t dmac_reg_idx = 0;
   7 uint8_t dmac_reg_values[0xFFFF];
   8
   9 uint8_t cdtv_dmac_reg_idx_read() {
  10     return dmac_reg_idx;
  11 }
  12
  13 /* DMAC Registers
  14 R   0x06 [B]    - Something
  15
  16     0x40 [W]    - ISTR
  17 RW  0x42 [W]    - CNTR
  18
  19     0x80 [L]    - WTC
  20     0x84 [L]    - ACR
  21
  22     0x8E [B]    - SASR
  23 W   0x8F [B]    - Something
  24     0x90        - SCMD
  25     0x91 [B]    - Something
  26     0x92 [B]    - Something?
  27 RW  0x93 [B]    - Something
  28
  29 R   0xA2?[W?]   - Some status thing?
  30 W   0xA4?[W?]   - Something
  31 W   0xA6?[W?]   - Something
  32 W   0xA8?[W?]   - Something
  33
  34     0xDE [W]    - ST_DMA
  35     0xE0 [W]    - SP_DMA
  36     0xE2 [W]    - CINT
  37     0xE4 [W]    - Something
  38     0xE4-0xE5   - Nothing
  39     0xE6 [W]    - Flush
  40 */
  41
  42 void cdtv_dmac_reg_idx_write(uint8_t value) {
  43     dmac_reg_idx = value;
  44 }
  45
  46 uint32_t cdtv_dmac_read(uint32_t address, uint8_t type) {
  47     uint32_t ret = 0;
  48
  49     switch (type) {
  50         case OP_TYPE_BYTE:
  51             return dmac_reg_values[address];
  52         case OP_TYPE_WORD:
  53             return be16toh(*((uint16_t *)&dmac_reg_values[address]));
  54         default:
  55             break;
  56     }
  57
  58     return ret;
  59 }
  60
  61 void cdtv_dmac_write(uint32_t address, uint32_t value, uint8_t type) {
  62     switch (type) {
  63         case OP_TYPE_BYTE:
  64             dmac_reg_values[address] = (uint8_t)value;
  65             return ;
  66         case OP_TYPE_WORD:
  67             printf("Help, it's a scary word write.\n");
  68             *((uint16_t *)&dmac_reg_values[address]) = htobe16(value);
  69             return;
  70     }
  71 }