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 #include <ip.h>
   9
  10 #include "usb.h"
  11 #include "dat.h"
  12
  13 static int
  14 cdcread(Dev *ep, uchar *p, int n)
  15 {
  16         return read(ep->dfd, p, n);
  17 }
  18
  19 static void
  20 cdcwrite(Dev *ep, uchar *p, int n)
  21 {
  22         if(write(ep->dfd, p, n) < 0){
  23                 fprint(2, "cdcwrite: %r\n");
  24         } else {
  25                 /*
  26                  * this may not work with all CDC devices. the
  27                  * linux driver sends one more random byte
  28                  * instead of a zero byte transaction. maybe we
  29                  * should do the same?
  30                  */
  31                 if(n % ep->maxpkt == 0)
  32                         write(ep->dfd, "", 0);
  33         }
  34 }
  35 int
  36 cdcinit(Dev *d)
  37 {
  38         int i;
  39         Usbdev *ud;
  40         uchar *b;
  41         Desc *dd;
  42         char *mac;
  43
  44         ud = d->usb;
  45         for(i = 0; i < nelem(ud->ddesc); i++)
  46                 if((dd = ud->ddesc[i]) != nil){
  47                         b = (uchar*)&dd->data;
  48                         if(b[1] == Dfunction && b[2] == Fnether){
  49                                 mac = loaddevstr(d, b[3]);
  50                                 if(mac != nil && strlen(mac) != 12){
  51                                         free(mac);
  52                                         mac = nil;
  53                                 }
  54                                 if(mac != nil){
  55                                         parseether(macaddr, mac);
  56                                         free(mac);
  57
  58                                         epread = cdcread;
  59                                         epwrite = cdcwrite;
  60                                         return 0;
  61                                 }
  62                         }
  63                 }
  64         return -1;
  65 }