reactos/drivers/dd/sound/dsp.c

   1 /*
   2  * COPYRIGHT:        See COPYING in the top level directory
   3  * PROJECT:          ReactOS kernel
   4  * FILE:             drivers/dd/sound/dsp.c
   5  * PURPOSE:          Digital Signal Processing ?
   6  * PROGRAMMER:       Snatched from ?
   7  *
   8  * UPDATE HISTORY:
   9  *              ??/??/??: Created
  10  *              10/23/02: Steven Edwards (Steven_Ed4153@yahoo.com)
  11  *                        Minor build fix
  12  */
  13
  14 #include "dsp.h"
  15 #include "sb16.h"
  16
  17 /************************************
  18  * unsigned char read_dsp(void)
  19  *
  20  * Reads the DSP chip
  21  * Arguments: none
  22  * Returns: Byte read
  23  ************************************/
  24 unsigned char read_dsp(unsigned short base)
  25 {
  26         while((inb(base+0x0e)&0x80)==0);        //Wait until there is something to read
  27         return  inb(base+0x0a);
  28 }
  29
  30 /************************************'
  31  * sb_status detect_dsp(void);
  32  *
  33  * Detects if a SB16 is installed
  34  * Arguments: None
  35  * Returns: Success or failure
  36  ************************************/
  37 sb_status detect_dsp(SB16* sb16)
  38 {
  39         for(base=0x200;base<0x280;base+=0x10)   //Tries to reset all DSP addresses there is
  40                 if(reset_dsp(base)==SB_TRUE)
  41                 {
  42                         sb16->base=base;
  43                         return SB_TRUE;
  44                 }
  45         return SB_FALSE;
  46 }
  47
  48 /**************************************
  49  * sb_status reset_dsp(unsigned short base_address);
  50  *
  51  * Tries to reset a DSP chip
  52  * Arguments: base address
  53  * Returns: Success of failure
  54  **************************************/
  55 sb_status reset_dsp(unsigned short base_address)
  56 {
  57         int delay;
  58
  59         outb(base_address+DSP_RESET_PORT,1);
  60         for(delay=0;delay<0xffff;delay++);
  61
  62         outb(base_address+DSP_RESET_PORT,0);
  63         for(delay=0;delay<0xffff;delay++);
  64
  65         if((inb(base_address+DSP_READ_STATUS_PORT)&0x80)==0) return SB_FALSE;
  66
  67         if(inb(base_address+DSP_READ_DATA_PORT)!=0xAA) return SB_FALSE;
  68
  69         return SB_TRUE;
  70 }
  71
  72 void write_dsp(unsigned short base,unsigned char data)
  73 {
  74   while ((inb(base+DSP_WRITE_PORT) & 0x80) != 0);
  75   outb(base+DSP_WRITE_PORT, data);
  76 }
  77