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 #define USB_TIMEOUT 50000
  10
  11 //Helper-routine: Convert a little-endian 4-byte word to an int
  12 static void int2chars(unsigned char *buff,unsigned int a) {
  13         buff[3]=(a>>24)&0xff;
  14         buff[2]=(a>>16)&0xff;
  15         buff[1]=(a>>8)&0xff;
  16         buff[0]=(a)&0xff;
  17 }
  18
  19 //Helper-routine: Convert an int to  little-endian 4-byte word
  20 unsigned int chars2int(unsigned char *buff) {
  21         unsigned int a;
  22         a=buff[3]<<24;
  23         a+=buff[2]<<16;
  24         a+=buff[1]<<8;
  25         a+=buff[0];
  26         return a;
  27 }
  28
  29 //This routine locates a scope by VID/PID and returns an opened handle to it.
  30 static usb_dev_handle *usbtmc_find_scope() {
  31         struct usb_bus *bus;
  32         struct usb_device *dev=NULL;
  33         usb_find_busses();
  34         usb_find_devices();
  35         for (bus=usb_busses; bus; bus=bus->next) {
  36                 for (dev=bus->devices; dev; dev=dev->next) {
  37                         //fprintf(stderr,"Prod/dev: %04X:%04X\n",dev->descriptor.idVendor,dev->descriptor.idProduct);
  38                         if (dev->descriptor.idVendor==0x400 && dev->descriptor.idProduct==0x5dc) {
  39                                 return usb_open(dev);
  40                         }
  41                 }
  42         }
  43         return NULL;
  44 }
  45
  46 //Send a scpi-command to the scope. The response goes into the buffer
  47 //called resp, with a size of resplen. If resp==NULL, no response
  48 //is requested.
  49 int usbtmc_sendscpi(usb_dev_handle *dev, char* cmd,
  50                 unsigned char *resp, int resplen) {
  51         unsigned char *buff;
  52         int len,r,i;
  53         int cmdlen = strlen(cmd);
  54         static unsigned char seq=0;
  55
  56
  57         buff=malloc(0x40);
  58         seq++;
  59         buff[0]=1; //func
  60         buff[1]=seq; buff[2]=~seq; //nseq
  61         buff[3]=0;
  62         int2chars(buff+4, cmdlen);
  63         buff[8]=1;
  64         buff[9]=0x00;
  65         buff[10]=0x00;
  66         buff[11]=0x00;
  67         //fprintf(stderr,"Writing header len=%d\n", cmdlen);
  68         //printb(buff,12);
  69         r=usb_bulk_write(dev, 1, (char*)buff, 12, USB_TIMEOUT);
  70         //fprintf(stderr,"%i bytes written. Writing cmd\n",r);
  71         //printb(cmd, cmdlen);
  72         r=usb_bulk_write(dev, 1, cmd, cmdlen, USB_TIMEOUT);
  73         //fprintf(stderr,"%i bytes written.\n",r);
  74         if (resp != NULL && resplen != 0) {
  75                 //send read command
  76                 buff[0]=2; //func
  77                 seq++;
  78                 buff[1]=seq; buff[2]=~seq; //nseq
  79                 int2chars(buff+4,0x40);
  80                 buff[8]=0;
  81                 buff[9]=0xA;
  82                 buff[10]=0;
  83                 buff[11]=0;
  84                 //fprintf(stderr,"Writing resp req header\n");
  85                 //printb(buff,12);
  86                 r=usb_bulk_write(dev, 1, (char*)buff, 12, USB_TIMEOUT);
  87                 //fprintf(stderr,"%i bytes written. Reading response hdr\n",r);
  88                 r=usb_bulk_read(dev, 2, (char*)buff, 0x40, USB_TIMEOUT);
  89                 //printb(buff,r);
  90                 len=chars2int(buff+4);
  91                 //fprintf(stderr,"%i bytes read. Resplen=%i\n",r,len);
  92                 for (i=0; i<(r-12); i++) {
  93                         if (i<resplen) resp[i] = buff[i+12];
  94                 }
  95                 //printb(resp,r-12);
  96                 if (len > 0x40-12) {
  97                         //fprintf(stderr," Reading response:\n");
  98                         if (resplen<len) len=resplen;
  99                         r=usb_bulk_read(dev, 2, (char*)resp+(0x40-12), len-(0x40-12), USB_TIMEOUT);
 100                         //fprintf(stderr,"%i bytes read, wanted %i.\n", r, len-(0x40-12));
 101                         return r+(0x40-12);
 102                 }
 103                 return len;
 104         }
 105         return 0;
 106 }
 107
 108 void usbtmc_claim(usb_dev_handle *sc)
 109 {
 110         usb_claim_interface(sc, 0);
 111 }
 112
 113 void usbtmc_release(usb_dev_handle *sc)
 114 {
 115         usb_release_interface(sc, 0);
 116 }
 117
 118 //Initialize the scope.
 119 usb_dev_handle* usbtmc_initscope(void) {
 120         int r;
 121         unsigned char buff[10];
 122         usb_dev_handle *dev;
 123
 124         //Init libusb
 125         usb_init();
 126         //Locate and open the scope
 127         dev = usbtmc_find_scope();
 128         if (!dev) {
 129                 printf("No scope found.\n");
 130                 exit(1);
 131         }
 132         usbtmc_claim(dev);
 133         //The following code isn't really necessary, the program works
 134         //OK without it too.
 135         r=usb_control_msg(dev, 0xC8, 9, 0, 0, (char*)buff, 4, USB_TIMEOUT);
 136         usbtmc_release(dev);
 137         if (r < 0) {
 138                 fprintf (stderr, "Error %d sending init message: %s\n",
 139                                 r, strerror (-r));
 140                 fprintf (stderr, "Do you have permission on the USB device?\n");
 141                 exit (1);
 142         }
 143         if (chars2int(buff)!=0x40005dc) {
 144                 fprintf(stderr,"Init: buff[%i]=%x\n",r,chars2int(buff));
 145         }
 146         return dev;
 147 }
 148
 149 void usbtmc_close(usb_dev_handle *sc)
 150 {
 151         //Free up and exit
 152         usb_close(sc);
 153 }