git.zerfleddert.de Git - rigol/blob - usbtmc.c

   1 #include <string.h>
   2 #include <stdio.h>
   3 #include <stdint.h>
   4 #include <usb.h>
   5 #include <arpa/inet.h>
   6
   7 #include "usbtmc.h"
   8
   9 //Helper-routine: Convert a little-endian 4-byte word to an int
  10 static void int2chars(unsigned char *buff,unsigned int a) {
  11         buff[3]=(a>>24)&0xff;
  12         buff[2]=(a>>16)&0xff;
  13         buff[1]=(a>>8)&0xff;
  14         buff[0]=(a)&0xff;
  15 }
  16
  17 //Helper-routine: Convert an int to  little-endian 4-byte word
  18 unsigned int chars2int(unsigned char *buff) {
  19         unsigned int a;
  20         a=buff[3]<<24;
  21         a+=buff[2]<<16;
  22         a+=buff[1]<<8;
  23         a+=buff[0];
  24         return a;
  25 }
  26
  27 //This routine locates a scope by VID/PID and returns an opened handle to it.
  28 static usb_dev_handle *usbtmc_find_scope() {
  29         struct usb_bus *bus;
  30         struct usb_device *dev=NULL;
  31         usb_find_busses();
  32         usb_find_devices();
  33         for (bus=usb_busses; bus; bus=bus->next) {
  34                 for (dev=bus->devices; dev; dev=dev->next) {
  35                         //fprintf(stderr,"Prod/dev: %04X:%04X\n",dev->descriptor.idVendor,dev->descriptor.idProduct);
  36                         if (dev->descriptor.idVendor==0x400 && dev->descriptor.idProduct==0x5dc) {
  37                                 return usb_open(dev);
  38                         }
  39                 }
  40         }
  41         return NULL;
  42 }
  43
  44 //Send a scpi-command to the scope. The response goes into the buffer
  45 //called resp, with a size of resplen. If resp==NULL, no response
  46 //is requested.
  47 int usbtmc_sendscpi(usb_dev_handle *dev, char* cmd,
  48                 unsigned char *resp, int resplen) {
  49         unsigned char *buff;
  50         int len,r,i;
  51         int cmdlen = strlen(cmd);
  52         static unsigned char seq=0;
  53
  54
  55         buff=malloc(0x40);
  56         seq++;
  57         buff[0]=1; //func
  58         buff[1]=seq; buff[2]=~seq; //nseq
  59         buff[3]=0;
  60         int2chars(buff+4, cmdlen);
  61         buff[8]=1;
  62         buff[9]=0x37;
  63         buff[10]=0x39;
  64         buff[11]=0x39;
  65         //fprintf(stderr,"Writing header len=%d\n", cmdlen);
  66         //printb(buff,12);
  67         r=usb_bulk_write(dev, 1, (char*)buff, 12, 1000);
  68         //fprintf(stderr,"%i bytes written. Writing cmd\n",r);
  69         //printb(cmd, cmdlen);
  70         r=usb_bulk_write(dev, 1, cmd, cmdlen, 1000);
  71         //fprintf(stderr,"%i bytes written.\n",r);
  72         if (resp != NULL && resplen != 0) {
  73                 //send read command
  74                 buff[0]=2; //func
  75                 seq++;
  76                 buff[1]=seq; buff[2]=~seq; //nseq
  77                 int2chars(buff+4,0x40);
  78                 buff[8]=1;
  79                 buff[9]=0xA;
  80                 buff[10]=0;
  81                 buff[11]=0;
  82                 //fprintf(stderr,"Writing resp req header\n");
  83                 //printb(buff,12);
  84                 r=usb_bulk_write(dev, 1, (char*)buff, 12, 1000);
  85                 //fprintf(stderr,"%i bytes written. Reading response hdr\n",r);
  86                 r=usb_bulk_read(dev, 2, (char*)buff, 0x40, 1000);
  87                 //printb(buff,r);
  88                 len=chars2int(buff+4);
  89                 //fprintf(stderr,"%i bytes read. Resplen=%i\n",r,len);
  90                 for (i=0; i<(r-12); i++) {
  91                         if (i<resplen) resp[i] = buff[i+12];
  92                 }
  93                 //printb(resp,r-12);
  94                 if (len > 0x40-12) {
  95                         //fprintf(stderr," Reading response:\n");
  96                         if (resplen<len) len=resplen;
  97                         r=usb_bulk_read(dev, 2, (char*)resp+(0x40-12), len-(0x40-12),1000);
  98                         //fprintf(stderr,"%i bytes read, wanted %i.\n", r, len-(0x40-12));
  99                         return r+(0x40-12);
 100                 }
 101                 return len;
 102         }
 103         return 0;
 104 }
 105
 106 //Initialize the scope.
 107 usb_dev_handle* usbtmc_initscope(void) {
 108         int r;
 109         unsigned char buff[10];
 110         usb_dev_handle *dev;
 111
 112         //Init libusb
 113         usb_init();
 114         //Locate and open the scope
 115         dev = usbtmc_find_scope();
 116         if (!dev) {
 117                 printf("No scope found.\n");
 118                 exit(1);
 119         } else {
 120                 printf("Scope found.\n");
 121         }
 122         usb_claim_interface(dev,0);
 123         //The following code isn't really necessary, the program works
 124         //OK without it too.
 125         r=usb_control_msg(dev, 0xC8, 9, 0, 0, (char*)buff, 4, 1000);
 126         if (r < 0) {
 127                 fprintf (stderr, "Error %d sending init message: %s\n",
 128                                 r, strerror (-r));
 129                 fprintf (stderr, "Do you have permission on the USB device?\n");
 130                 exit (1);
 131         }
 132         if (chars2int(buff)!=0x40005dc) {
 133                 fprintf(stderr,"Init: buff[%i]=%x\n",r,chars2int(buff));
 134         }
 135         return dev;
 136 }
 137
 138 void usbtmc_close(usb_dev_handle *sc)
 139 {
 140         //Free up and exit
 141         usb_release_interface(sc,0);
 142         usb_close(sc);
 143 }