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 <bio.h>
   9 #include <auth.h>
  10 #include <fcall.h>
  11 #include <9p.h>
  12 #include <ip.h>
  13
  14 #include "usb.h"
  15 #include "dat.h"
  16
  17 static int
  18 cdcread(Dev *ep, uchar *p, int n)
  19 {
  20         return read(ep->dfd, p, n);
  21 }
  22
  23 static void
  24 cdcwrite(Dev *ep, uchar *p, int n)
  25 {
  26         if(write(ep->dfd, p, n) < 0){
  27                 fprint(2, "cdcwrite: %r\n");
  28         } else {
  29                 /*
  30                  * this may not work with all CDC devices. the
  31                  * linux driver sends one more random byte
  32                  * instead of a zero byte transaction. maybe we
  33                  * should do the same?
  34                  */
  35                 if(n % ep->maxpkt == 0)
  36                         write(ep->dfd, "", 0);
  37         }
  38 }
  39 int
  40 cdcinit(Dev *d)
  41 {
  42         int i;
  43         Usbdev *ud;
  44         uchar *b;
  45         Desc *dd;
  46         char *mac;
  47
  48         ud = d->usb;
  49         for(i = 0; i < nelem(ud->ddesc); i++)
  50                 if((dd = ud->ddesc[i]) != nil){
  51                         b = (uchar*)&dd->data;
  52                         if(b[1] == Dfunction && b[2] == Fnether){
  53                                 mac = loaddevstr(d, b[3]);
  54                                 if(mac != nil && strlen(mac) != 12){
  55                                         free(mac);
  56                                         mac = nil;
  57                                 }
  58                                 if(mac != nil){
  59                                         parseether(macaddr, mac);
  60                                         free(mac);
  61
  62                                         epread = cdcread;
  63                                         epwrite = cdcwrite;
  64                                         return 0;
  65                                 }
  66                         }
  67                 }
  68         return -1;
  69 }