sys/src/cmd/nusb/ether/cdc.c

   1 /*
   2  * generic CDC
   3  */
   4
   5 #include <u.h>
   6 #include <libc.h>
   7 #include <thread.h>
   8
   9 #include "usb.h"
  10 #include "dat.h"
  11
  12 #include <ip.h>
  13
  14 static int
  15 cdcreceive(Dev *ep)
  16 {
  17         Block *b;
  18         int n;
  19
  20         b = allocb(Maxpkt);
  21         if((n = read(ep->dfd, b->wp, b->lim - b->base)) < 0){
  22                 freeb(b);
  23                 return -1;
  24         }
  25         b->wp += n;
  26         etheriq(b, 1);
  27         return 0;
  28 }
  29
  30 static void
  31 cdctransmit(Dev *ep, Block *b)
  32 {
  33         int n;
  34
  35         n = BLEN(b);
  36         if(write(ep->dfd, b->rp, n) < 0){
  37                 freeb(b);
  38                 return;
  39         }
  40         freeb(b);
  41
  42         /*
  43          * this may not work with all CDC devices. the
  44          * linux driver sends one more random byte
  45          * instead of a zero byte transaction. maybe we
  46          * should do the same?
  47          */
  48         if((n % ep->maxpkt) == 0)
  49                 write(ep->dfd, "", 0);
  50 }
  51
  52 int
  53 cdcinit(Dev *d)
  54 {
  55         int i;
  56         Usbdev *ud;
  57         uchar *b;
  58         Desc *dd;
  59         char *mac;
  60
  61         ud = d->usb;
  62         for(i = 0; i < nelem(ud->ddesc); i++)
  63                 if((dd = ud->ddesc[i]) != nil){
  64                         b = (uchar*)&dd->data;
  65                         if(b[1] == Dfunction && b[2] == Fnether){
  66                                 mac = loaddevstr(d, b[3]);
  67                                 if(mac != nil && strlen(mac) != 12){
  68                                         free(mac);
  69                                         mac = nil;
  70                                 }
  71                                 if(mac != nil){
  72                                         parseether(macaddr, mac);
  73                                         free(mac);
  74
  75                                         epreceive = cdcreceive;
  76                                         eptransmit = cdctransmit;
  77                                         return 0;
  78                                 }
  79                         }
  80                 }
  81         return -1;
  82 }