da_dma.c

rt 7520采集卡 linux驱动源代码

/*
	FILE NAME: da_dma.c

	FILE DESCRIPTION:

		D/A conversion demonstrating changing the wave form as the
		program runs.

		Each DMA channel uses a buffer of up to 64 kilobytes.  During
		each DMA, data from a subbuffer equal in size to 1/2 the FIFO
		size is copied to the FIFO and used for wave generation.  After
		copying, the driver sets a flag in the control buffer.  Every
		subbuffer has its own 1-byte flag.

		The application program must check flags and replace subbuffers
		marked as copied with new data and then set flag in control
		buffer to indicate the buffer is ready.

		If conversion is occurring too quickly and the FIFO empties
		before new data copied, the driver will stop conversion and set
		a FIFO empty flag in the control buffer.

		Maximum conversion rate depends on computer system used.

		General programming sequence:

			1. Open the device for reading and writing (fopen).
			2. Setup DMA and obtain DMA buffer (setDA_DMA7520).
			3. Obtain control buffer (get_control_buf7520).
			4. Load DMA buffer with initial values (using memcpy or
			   just "=").  Then load the buffer to the driver
			   (setWriteBuffer7520) which will load initial values
			   into the FIFO.
			5. Setup DA converter (SetupDAC7520).
			6. Setup DA clock - it will start conversion
			   (SetDACRate7520).
			7. Check the control buffer flags and renew data in the
			   DMA buffer.  Set buffer ready flag when new data is
			   loaded.
			8. Unset DMA when program is finished
			   (UnSetDMAMode7520).
			9. Close the device.

	PROJECT NAME: Linux DM7520 Driver, Library, and Example Programs

	PROJECT VERSION: (Defined in README.TXT)

	Copyright 2004 RTD Embedded Technologies, Inc.  All Rights Reserved.
*/

#include <stdio.h>	//printf
#include <stdlib.h>	//exit
#include <errno.h>	//errno
#include <math.h>	//sin
#include "dm7520_library.h"


int DABUFFERSIZE;  // Equals to 1/2 FIFO. Will be set during the program initialization
int16_t *dabuffer1;	//addres of buffer 1
int16_t *dabuffer2;	//address of buffer 2
char *contBuf;		//address of control buffer


//load buffer with upper part of square signal
void setLowerBufSq(int16_t *buffer, int j) {
	int i;
	int sample;
     for (i=0; i<DABUFFERSIZE;i++){
	 	sample=-j*20;
	 	buffer[i]=sample<<3;
     }
}

//load buffer with lower part of square signal
void setUpperBufSq(int16_t *buffer, int j) {
	int i;
	int sample;
     for (i=0;i<DABUFFERSIZE;i++) {
	 	sample = j*20;
	 	buffer[i]=sample<<3;
     }
}

//load buffer with lower part of sine wave
void setLowerBufSin(int16_t *buffer, int j) {
	int i;
	int sample;
	float fok, val;
     for (i=0; i<DABUFFERSIZE;i++){
      	fok=(float)i*(M_PI/DABUFFERSIZE);
      	val=sin(fok);
			sample=j*20*val;
      	buffer[i]=sample<<3;
     }
}

//load buffer with upper part of sine wave
void setUpperBufSin(int16_t *buffer, int j) {
	int i;
	int sample;
	float fok, val;
     for (i=0;i<DABUFFERSIZE;i++) {
      	fok=(float)i*(M_PI/DABUFFERSIZE);
      	val=-sin(fok);
			sample=j*20*val;
      	buffer[i]=sample<<3;
     }
}

//=====================================================================
int main(int argc, char * argv[])
{
 FILE * infile;	
 int i1=0;	//index
 int i2=0;
 int fifosize;

 int j=0;	//index
 int ret;	// return code
 int devno;	// device handler
 int bi1 = 0; //buffer1 index
 int bi2 = 0; //buffer2 index
 int bi1num;
	//number of indexes
 int bi2num;	//number of indexes


 if (argc<2) {fprintf(stderr,"Usage: %s <device>\n",argv[0]);exit(1);}

 if (NULL==(infile=fopen(argv[1],"r+"))) //open device. Enough to open for reading only
   {
    fprintf(stderr,"Cannot open file, errno=%d\n",errno);
    perror("Error is");
    exit(2);
   }

   devno = fileno(infile);		// get device handler
 	InitBoard7520(devno);		// Initialize the device
	
  ret = dm7520_getFifoSize(devno,&fifosize);
  printf ("FIFOSIZE=%d ret=%d\n", fifosize, ret);
  DABUFFERSIZE = fifosize/2;

ret = DACClockFreeRun7520(devno,1);	//DAC start/stop mode
if (ret) printf("free run ret=%d\n", ret);
ret = DACClockStopSelect7520(devno, 7);	//set DAC clock stop to software
if (ret) printf("dac stop select ret=%d\n", ret);
ret = DACClockStartSelect7520(devno, 7);	//set DAC clock start to software
if (ret) printf("dacstartselect ret=%d\n", ret);
ret = SetDACRate7520(devno, 50000);	//start da coversion at 100 kHz
if (ret) printf("setdac rate ret=%d\n", ret);
 
 ret = DACClockStop7520(devno);
 if (ret) printf("stop dac ret=%d\n", ret);

if (SetupDAC7520(devno,DM7520_WRITE_DA1,AOUT_BIP5,DAC_CYCLE_SINGLE,DAC_START_DAC_CLK)) {
    printf ("could not setup DA1\n");
    goto label1; // set up DAC1
}
if (SetupDAC7520(devno,DM7520_WRITE_DA2,AOUT_BIP5,DAC_CYCLE_SINGLE,DAC_START_DAC_CLK)){
    printf ("could not setup DA2\n");
    goto label1; //set up DAC2
}    

//set DMA channel  0 and get the buffer1
    ret = setDA_DMA7520(devno, DM7520_WRITE_DA1,0, &dabuffer1, DMATEMPSIZE); //size in bytes
    if (ret) {
		printf("setDMA0 error=%X\n", ret);
		goto label1;
    }

//set DMA channel 1 and get the buffer2
    ret = setDA_DMA7520(devno, DM7520_WRITE_DA2, 1, &dabuffer2, DMATEMPSIZE);
    if (ret) {
		printf("setDMA error1=%X\n", ret);
		goto label1;
    }

//get control buffer
	ret = get_control_buf7520(devno, &contBuf);

    if (ret) {
		printf(" error getting control buf=%X\n", ret);
		goto label1;
    }


	bi1num = DMATEMPSIZE/(DABUFFERSIZE*2); // divide DMA buffer size by size of 1/2 FIFO in bytes
	bi2num = DMATEMPSIZE/(DABUFFERSIZE*2); // divide DMA buffer size by size of 1/2 FIFO in bytes

// initialize the DMA buffer of wave form 1
	for (bi1=0; bi1<bi1num; bi1++) {
		i1++;
		if (i1>100) j = 200-i1;
		else j = i1;
    	if (1==i1%2){
			setLowerBufSq(dabuffer1+DABUFFERSIZE*bi1,  j);
        }
    	else {
    		setUpperBufSq(dabuffer1+DABUFFERSIZE*bi1,  j);
    	}
		*(contBuf+bi1) = BUFFER_READY;
	}


// initialize the DMA buffer of wave form 2
	for (bi2=0; bi2<bi2num; bi2++) {
		i2++;
		if (i2>100) j = 200-i2;
		else j = i2;
    	if (1==i2%2){
			setLowerBufSin(dabuffer2+DABUFFERSIZE*bi2,  j);
        }
    	else {
    		setUpperBufSin(dabuffer2+DABUFFERSIZE*bi2,  j);
    	}
		*(contBuf+CONTROLFLAGSIZE+bi2) = BUFFER_READY;
	}

// load data to DAC1 FIFO and initialize control buffer flags




if (setWriteBuffer7520(devno, DM7520_WRITE_DA1, 0, DMATEMPSIZE) ) { // size in bytes
    printf("Error setting buffer for DMA0\n");
    goto label1;
}

// load data to DAC2 FIFO and initialize control buffer flags
if (setWriteBuffer7520(devno, DM7520_WRITE_DA2, 1, DMATEMPSIZE) ){ // size in bytes
 printf("Error setting buffer for DMA1\n");
 goto label1;
}


 DACClockStart7520(devno);	//Start DA conversion

    while ((i1<200)&&(i2<200)) {
	if (bi1>=bi1num)bi1 = 0;
	if (bi2>=bi2num)bi2 = 0;

	if ((BUFFER_NOT_READY==*(contBuf+bi1))||(BUFFER_NOT_READY==*(contBuf+CONTROLFLAGSIZE+bi2))){
	    printf("Program stopped because fifo got empty because of too high convertion rate  - buffer not ready\n");
	    goto label1;
	}

	if ((FIFO_EMPTY==*(contBuf+bi1))||(FIFO_EMPTY==*(contBuf+CONTROLFLAGSIZE+bi2))){
	    printf("Program stopped because could not get copied due to too high convertion rate - FIFO Empty\n");
	    goto label1;
	}

	if (BUFFER_COPIED==*(contBuf+bi1)) {   //DMA done need to update the buffer1

    	    i1++;

			if (i1>100) j = 200-i1;
			else j = i1;

    	    if (1==i1%2){
        	setLowerBufSq(dabuffer1+DABUFFERSIZE*bi1,  j);
            }
    	    else {
    		setUpperBufSq(dabuffer1+DABUFFERSIZE*bi1,  j);
    	    }
			*(contBuf+bi1) = BUFFER_READY;
			bi1++;

      }

	if (BUFFER_COPIED==*(contBuf+CONTROLFLAGSIZE+bi2)) {   //DMA done need to update the buffer2

    	    i2++;
//	    printf("i1=%d\n",i1);
			if (i2>100) j = 200-i2;
			else j = i2;


    	    if (1==i2%2){     //lower buffer DMA done, need to update lower buffer1
        	setLowerBufSin(dabuffer2+DABUFFERSIZE*bi2,  j);
            }
    	    else {
    		setUpperBufSin(dabuffer2+DABUFFERSIZE*bi2,  j);    //upper buffer DMA done, need to update upper buffer1
    	    }
			*(contBuf+CONTROLFLAGSIZE+bi2) = BUFFER_READY;
			bi2++;
      }
    }
// wait while buffer is not read
    
 while ((*(contBuf+CONTROLFLAGSIZE+bi2-1) == BUFFER_READY) ||
	    (*(contBuf+CONTROLFLAGSIZE+bi1-1) == BUFFER_READY));

// printf ("\nPlease wait while  unsetting the DMA channels\n");

label1:

 ret = UnSetDMAMode7520(devno, 1);	// unset DMA1
 if (ret) printf("dma1 unset with code=%X\n", ret);

 ret = UnSetDMAMode7520(devno, 0);	// unset DMA0
 if (ret) printf("dma0 unset with code=%X\n", ret);

 fclose(infile);	// close device
 if (ret) printf("device closed\n");
 return(0);
}