gemtag/gemtag.c

   1 /*
   2  * (C) 2006 by Frank Zirkelbach <hackbard@hackdaworld.org>
   3  *
   4  *  This program is free software; you can redistribute it and/or modify
   5  *  it under the terms of the GNU General Public License version 2
   6  *  as published by the Free Software Foundation
   7  *
   8  *  This program is distributed in the hope that it will be useful,
   9  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  *  GNU General Public License for more details.
  12  *
  13  *  You should have received a copy of the GNU General Public License
  14  *  along with this program; if not, write to the Free Software
  15  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16  */
  17
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <unistd.h>
  21 #include <string.h>
  22 #include <errno.h>
  23
  24 #include <usb.h>
  25 #include "gemtag.h"
  26
  27 int hexdump(unsigned char *data,int len) {
  28         int i;
  29
  30         for(i=0;i<len;i++) printf("%02x ",data[i]);
  31         printf("\n");
  32
  33         return 0;
  34 }
  35
  36 struct usb_device *find_device(unsigned short vendor,unsigned short device) {
  37
  38         struct usb_bus *bus;
  39         struct usb_device *dev;
  40
  41         bus=usb_get_busses();
  42         while(bus) {
  43                 dev=bus->devices;
  44                 while(dev) {
  45                         if(dev->descriptor.idVendor==vendor &&
  46                            dev->descriptor.idProduct==device)
  47                                 return dev;
  48                         dev=dev->next;
  49                 }
  50                 bus=bus->next;
  51         }
  52         return NULL;
  53 }
  54
  55 u_int16_t gemtag_calc_crc(unsigned char *data,u_int16_t len) {
  56
  57         u_int16_t crc_polynom;
  58         u_int16_t crc_preset;
  59         u_int16_t crc;
  60         int i,j;
  61
  62         crc_polynom=0x8408;
  63         crc_preset=0xffff;
  64         crc=0xffff;
  65
  66         for(i=0;i<len;i++) {
  67                 crc^=data[i];
  68                 for(j=0;j<8;j++) {
  69                         if(crc&0x0001)
  70                                 crc=(crc>>1)^crc_polynom;
  71                         else
  72                                 crc=(crc>>1);
  73                 }
  74         }
  75         return crc;
  76 }
  77
  78 int gemtag_transcieve(struct gemtag_handle *gh,unsigned char cmd,
  79                          unsigned char *tx,unsigned int tx_len,
  80                          unsigned char *rx,unsigned int *rx_len) {
  81
  82         unsigned char txbuf[256];
  83         unsigned char rxbuf[256];
  84         struct gemtag_cmd_hdr *txhdr;
  85         struct gemtag_cmd_hdr *rxhdr;
  86         u_int16_t *crcptr;
  87         int ret,size;
  88
  89         txhdr=(struct gemtag_cmd_hdr *)txbuf;
  90         rxhdr=(struct gemtag_cmd_hdr *)rxbuf;
  91
  92         txhdr->start=0xa5;
  93         txhdr->seq=++(gh->seq);
  94         txhdr->cmd=cmd;
  95         txhdr->len=htons(tx_len);
  96         size=sizeof(struct gemtag_cmd_hdr);
  97         memcpy(txbuf+size,tx,tx_len);
  98
  99         /* crc check */
 100         if(gh->capabilities&GEMTAG_CAP_CRC) {
 101                 size+=tx_len;
 102                 crcptr=(u_int16_t *)(txbuf+size);
 103                 *crcptr=htons(gemtag_calc_crc(txbuf,size));
 104                 size+=2;
 105         }
 106
 107         /* usb write */
 108         printf("-> ");
 109         hexdump(txbuf,size);
 110         usb_clear_halt(gh->handle,0x02);
 111         ret=usb_bulk_write(gh->handle,0x02,txbuf,size,0);
 112         if(ret<=0) {
 113                 perror("usb bulk write");
 114                 return ret;
 115         }
 116
 117         /* usb read */
 118         usb_clear_halt(gh->handle,0x81);
 119         ret=usb_bulk_read(gh->handle,0x81,rxbuf,sizeof(rxbuf),0);
 120         size=ret;
 121         if(ret<=0) {
 122                 perror("usb bulk read");
 123                 return ret;
 124         }
 125         printf("-> ");
 126         hexdump(rxbuf,ret);
 127
 128         if(rxhdr->seq!=txhdr->seq)
 129                 puts("transmitted/recieved sequence number do not match");
 130
 131         /* crc check */
 132
 133
 134         *rx_len=ntohs(rxhdr->len);
 135         memcpy(rx,rxbuf+sizeof(struct gemtag_cmd_hdr),
 136                ret-sizeof(struct gemtag_cmd_hdr)+2);
 137         hexdump(rxbuf,ret+2);
 138
 139         return 0;
 140 }
 141
 142 struct gemtag_handle *gemtag_open(void) {
 143         struct usb_device *gemtag;
 144         unsigned char rbuf[16];
 145         unsigned int rlen;
 146         unsigned int i,numconf;
 147         unsigned int j,numint;
 148         unsigned int k,numalt;
 149         struct gemtag_handle *gh;
 150
 151         rlen=sizeof(rbuf);
 152
 153         usb_init();
 154         usb_find_busses();
 155         usb_find_devices();
 156
 157         gemtag=find_device(USB_VENDOR_GEMTAG, USB_DEVICE_X501);
 158         if(!gemtag) return NULL;
 159
 160         gh=malloc(sizeof(struct gemtag_handle));
 161         if(!gh) return NULL;
 162
 163         memset(gh,0,sizeof(struct gemtag_handle));
 164
 165         numconf=gemtag->descriptor.bNumConfigurations;
 166         printf("found gemtag (%02x/%02x), %u configuration(s)\n",
 167                gemtag->descriptor.idVendor,
 168                gemtag->descriptor.idProduct,numconf);
 169         for(i=0;i<numconf;i++) {
 170                 numint=gemtag->config[i].bNumInterfaces;
 171                 printf("  config %u [nr %u] has %u interface(s)\n",
 172                        i,gemtag->config[i].bConfigurationValue,
 173                        numint);
 174                 for(j=0;j<numint;j++) {
 175                         numalt=gemtag->config[i].interface[j].num_altsetting;
 176                         printf("    interface %u has %u altsetting(s): ",
 177                                j,numalt);
 178                         for(k=0;k<numalt;k++)
 179                                 printf("%u ",
 180                 gemtag->config[i].interface[j].altsetting[k].bAlternateSetting);
 181                         printf("\n");
 182                 }
 183         }
 184
 185         gh->handle=usb_open(gemtag);
 186         if(!gh->handle)
 187                 goto out_free;
 188         puts("usb_open successfull");
 189
 190         if(usb_set_configuration(gh->handle,1)) {
 191                 perror("set config");
 192                 goto out_free;
 193         }
 194         puts("configuration 1 successfully set");
 195
 196         if(usb_claim_interface(gh->handle,0)) {
 197                 perror("claim interface");
 198                 goto out_free;
 199         }
 200         puts("interface 0 claimed");
 201
 202         while(usb_set_altinterface(gh->handle,0))
 203                 printf("trying to set alt interface\n");
 204         puts("alt setting 0 selected");
 205
 206         gh->capabilities|=GEMTAG_CAP_CRC;
 207
 208         gemtag_transcieve(gh,GEMTAG_CMD_GET_FW_VERSION,
 209                           NULL,0,rbuf,&rlen);
 210
 211         return gh;
 212
 213 out_free:
 214         free(gh);
 215         return NULL;
 216 }
 217
 218 int main(int argc, char **argv) {
 219
 220         struct gemtag_handle *gh;
 221
 222         gh=gemtag_open();
 223
 224         return 1;
 225 }
 226