bsd/dev/arm/cons.c

   1 /*
   2  * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
   3  */
   4 /*
   5  * Copyright (c) 1987, 1988 NeXT, Inc.
   6  *
   7  * HISTORY 7-Jan-93  Mac Gillon (mgillon) at NeXT Integrated POSIX support
   8  *
   9  * 12-Aug-87  John Seamons (jks) at NeXT Ported to NeXT.
  10  */
  11
  12 /*
  13  * Indirect driver for console.
  14  */
  15 #include <sys/param.h>
  16 #include <sys/systm.h>
  17 #include <sys/conf.h>
  18 #include <sys/ioctl.h>
  19 #include <sys/tty.h>
  20 #include <sys/proc.h>
  21 #include <sys/uio.h>
  22
  23 struct tty      *constty;               /* current console device */
  24
  25 /*
  26  * The km driver supplied the default console device for the systems
  27  * (usually a raw frame buffer driver, but potentially a serial driver).
  28  */
  29 extern struct tty *km_tty[1];
  30
  31 /*
  32  * cdevsw[] entries for the console device driver
  33  */
  34 int cnopen(__unused dev_t dev, int flag, int devtype, proc_t pp);
  35 int cnclose(__unused dev_t dev, int flag, int mode, proc_t pp);
  36 int cnread(__unused dev_t dev, struct uio *uio, int ioflag);
  37 int cnwrite(__unused dev_t dev, struct uio *uio, int ioflag);
  38 int cnioctl(__unused dev_t dev, u_long cmd, caddr_t addr, int flg, proc_t p);
  39 int cnselect(__unused dev_t dev, int flag, void * wql, proc_t p);
  40
  41 static dev_t
  42 cndev(void)
  43 {
  44         if (constty)
  45                 return constty->t_dev;
  46         else
  47                 return km_tty[0]->t_dev;
  48 }
  49
  50 int
  51 cnopen(__unused dev_t dev, int flag, int devtype, struct proc *pp)
  52 {
  53         dev = cndev();
  54         return ((*cdevsw[major(dev)].d_open)(dev, flag, devtype, pp));
  55 }
  56
  57
  58 int
  59 cnclose(__unused dev_t dev, int flag, int mode, struct proc *pp)
  60 {
  61         dev = cndev();
  62         return ((*cdevsw[major(dev)].d_close)(dev, flag, mode, pp));
  63 }
  64
  65
  66 int
  67 cnread(__unused dev_t dev, struct uio *uio, int ioflag)
  68 {
  69         dev = cndev();
  70         return ((*cdevsw[major(dev)].d_read)(dev, uio, ioflag));
  71 }
  72
  73
  74 int
  75 cnwrite(__unused dev_t dev, struct uio *uio, int ioflag)
  76 {
  77         dev = cndev();
  78         return ((*cdevsw[major(dev)].d_write)(dev, uio, ioflag));
  79 }
  80
  81
  82 int
  83 cnioctl(__unused dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
  84 {
  85         dev = cndev();
  86
  87         /*
  88          * XXX This check prevents the cons.c code from being shared between
  89          * XXX all architectures; it is probably not needed on ARM, either,
  90          * XXX but I have no test platforms or ability to run a kernel.
  91          *
  92          * Superuser can always use this to wrest control of console
  93          * output from the "virtual" console.
  94          */
  95         if ((unsigned) cmd == TIOCCONS && constty) {
  96                 int             error = proc_suser(p);
  97                 if (error)
  98                         return (error);
  99                 constty = NULL;
 100                 return (0);
 101         }
 102         return ((*cdevsw[major(dev)].d_ioctl)(dev, cmd, addr, flag, p));
 103 }
 104
 105
 106 int
 107 cnselect(__unused dev_t dev, int flag, void *wql, struct proc *p)
 108 {
 109         dev = cndev();
 110         return ((*cdevsw[major(dev)].d_select)(dev, flag, wql, p));
 111 }