Modules/x86/ISADMA/dma.c

   1 /*\r
   2  * AcessOS 1.0\r
   3  * DMA Driver\r
   4  */\r
   5 #include <acess.h>\r
   6 #include <modules.h>\r
   7 \r
   8 #define DMA_SIZE        (0x2400)\r
   9 #define DMA_ADDRESS(c)  ((c)*DMA_SIZE+0x500)    //Save Space for IDT and BDA\r
  10 \r
  11 #define LOWB(x) ((x)&0xFF)\r
  12 #define HIB(x)  (((x)>>8)&0xFF)\r
  13 #define HIW(x)  (((x)>>16)&0xFFFF)\r
  14 \r
  15 // === TYPES ===\r
  16 typedef struct\r
  17 {\r
  18          int    mode;\r
  19         char    *address;\r
  20 } t_dmaChannel;\r
  21 \r
  22 // === PROTOTYPES ===\r
  23  int    DMA_Install(char **Arguments);\r
  24 void    DMA_SetChannel(int Channel, int length, int read);\r
  25  int    DMA_ReadData(int channel, int count, void *buffer);\r
  26  int    DMA_WriteData(int channel, int count, const void *buffer);\r
  27 \r
  28 // === CONSTANTS ===\r
  29 const Uint8 cMASKPORT [8] = { 0x0A, 0x0A, 0x0A, 0x0A, 0xD4, 0xD4, 0xD4, 0xD4 };\r
  30 const Uint8 cMODEPORT [8] = { 0x0B, 0x0B, 0x0B, 0x0B, 0xD6, 0xD6, 0xD6, 0xD6 };\r
  31 const Uint8 cCLEARPORT[8] = { 0x0C, 0x0C, 0x0C, 0x0C, 0xD8, 0xD8, 0xD8, 0xD8 };\r
  32 const Uint8 cPAGEPORT [8] = { 0x87, 0x83, 0x81, 0x82, 0x8F, 0x8B, 0x89, 0x8A };\r
  33 const Uint8 cADDRPORT [8] = { 0x00, 0x02, 0x04, 0x06, 0xC0, 0xC4, 0xC8, 0xCC };\r
  34 const Uint8 cCOUNTPORT[8] = { 0x01, 0x03, 0x05, 0x07, 0xC2, 0xC6, 0xCA, 0xCE };\r
  35 \r
  36 // === GLOBALS ===\r
  37 MODULE_DEFINE(0, 0x0100, x86_ISADMA, DMA_Install, NULL, NULL);\r
  38 char    *dma_addresses[8];\r
  39 t_dmaChannel    dma_channels[8];\r
  40 \r
  41 // === CODE ===\r
  42 /**\r
  43  * \brief Initialise DMA channels\r
  44  * \param Arguments     Arguments passed at boot time\r
  45  */\r
  46 int DMA_Install(char **Arguments)\r
  47 {\r
  48         Uint    i;\r
  49         for(i=8;i--;)\r
  50         {\r
  51                 outb( cMASKPORT[i], 0x04 | (i & 0x3) ); // mask channel\r
  52                 outb( cCLEARPORT[i], 0x00 );\r
  53                 outb( cMODEPORT[i], 0x48 | (i & 0x3) ); //Read Flag\r
  54                 outb( 0xd8, 0xff);      //Reset Flip-Flop\r
  55                 outb( cADDRPORT[i], LOWB(DMA_ADDRESS(i)) );     // send address\r
  56                 outb( cADDRPORT[i], HIB(DMA_ADDRESS(i)) );      // send address\r
  57                 outb( 0xd8, 0xff);      //Reset Flip-Flop\r
  58                 outb( cCOUNTPORT[i], LOWB(DMA_SIZE) );      // send size\r
  59                 outb( cCOUNTPORT[i], HIB(DMA_SIZE) );       // send size\r
  60                 outb( cPAGEPORT[i], LOWB(HIW(DMA_ADDRESS(i))) );        // send page\r
  61                 outb( cMASKPORT[i], i & 0x3 );              // unmask channel\r
  62                 \r
  63                 dma_channels[i].mode = 0;\r
  64                 dma_addresses[i] = (char*)DMA_ADDRESS(i);\r
  65                 dma_addresses[i] += KERNEL_BASE;\r
  66         }\r
  67         return MODULE_ERR_OK;\r
  68 }\r
  69 \r
  70 /**\r
  71  * \fn void DMA_SetChannel(int Channel, int length, int read)\r
  72  * \brief Set DMA Channel Length and RW\r
  73  */\r
  74 void DMA_SetChannel(int Channel, int length, int read)\r
  75 {\r
  76         Uint    chan = Channel & 7;\r
  77         read = !!read;\r
  78         if(length > DMA_SIZE)   length = DMA_SIZE;\r
  79         length --;      //Adjust for DMA\r
  80         outb( cMASKPORT[chan], 0x04 | (chan & 0x3) );           // mask channel\r
  81         outb( cCLEARPORT[chan], 0x00 );\r
  82         outb( cMODEPORT[chan], (0x44 + (!read)*4) | (chan & 0x3) );\r
  83         outb( cADDRPORT[chan], LOWB(DMA_ADDRESS(chan)) );               // send address\r
  84         outb( cADDRPORT[chan], HIB(DMA_ADDRESS(chan)) );                // send address\r
  85         outb( cPAGEPORT[chan], HIW(DMA_ADDRESS(chan)) );                // send page\r
  86         outb( cCOUNTPORT[chan], LOWB(length) );      // send size\r
  87         outb( cCOUNTPORT[chan], HIB(length) );       // send size\r
  88         outb( cMASKPORT[chan], chan & 0x3 );              // unmask channel\r
  89         dma_addresses[chan] = (char*)DMA_ADDRESS(chan);\r
  90         dma_addresses[chan] += KERNEL_BASE;\r
  91 }\r
  92 \r
  93 /**\r
  94  * \fn void DMA_ReadData(int channel, int count, void *buffer)\r
  95  * \brief Read data from a DMA buffer\r
  96  */\r
  97 int DMA_ReadData(int channel, int count, void *buffer)\r
  98 {\r
  99         if(channel < 0 || channel > 7)\r
 100                 return -1;\r
 101         if(count < 0 || count > DMA_SIZE)\r
 102                 return -2;\r
 103         //LogF("memcpy(*0x%x, dma_channels[channel].address, count)\n", buffer\r
 104         memcpy(buffer, dma_addresses[channel], count);\r
 105         return 0;\r
 106 }\r
 107 \r
 108 /**\r
 109  * \fn void DMA_WriteData(int channel, int count, void *buffer)\r
 110  * \brief Write data to a DMA buffer\r
 111  */\r
 112 int DMA_WriteData(int channel, int count, const void *buffer)\r
 113 {\r
 114         if(channel < 0 || channel > 7)\r
 115                 return -1;\r
 116         if(count < 0 || count > DMA_SIZE)\r
 117                 return -2;\r
 118         \r
 119         memcpy(dma_addresses[channel], buffer, count);\r
 120         \r
 121         return 0;\r
 122 }\r