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
  51 int
  52 cnopen(__unused dev_t dev, int flag, int devtype, struct proc *pp)
  53 {
  54         dev = cndev();
  55         return (*cdevsw[major(dev)].d_open)(dev, flag, devtype, pp);
  56 }
  57
  58
  59 int
  60 cnclose(__unused dev_t dev, int flag, int mode, struct proc *pp)
  61 {
  62         dev = cndev();
  63         return (*cdevsw[major(dev)].d_close)(dev, flag, mode, pp);
  64 }
  65
  66
  67 int
  68 cnread(__unused dev_t dev, struct uio *uio, int ioflag)
  69 {
  70         dev = cndev();
  71         return (*cdevsw[major(dev)].d_read)(dev, uio, ioflag);
  72 }
  73
  74
  75 int
  76 cnwrite(__unused dev_t dev, struct uio *uio, int ioflag)
  77 {
  78         dev = cndev();
  79         return (*cdevsw[major(dev)].d_write)(dev, uio, ioflag);
  80 }
  81
  82
  83 int
  84 cnioctl(__unused dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
  85 {
  86         dev = cndev();
  87
  88         /*
  89          * XXX This check prevents the cons.c code from being shared between
  90          * XXX all architectures; it is probably not needed on ARM, either,
  91          * XXX but I have no test platforms or ability to run a kernel.
  92          *
  93          * Superuser can always use this to wrest control of console
  94          * output from the "virtual" console.
  95          */
  96         if ((unsigned) cmd == TIOCCONS && constty) {
  97                 int             error = proc_suser(p);
  98                 if (error) {
  99                         return error;
 100                 }
 101                 constty = NULL;
 102                 return 0;
 103         }
 104         return (*cdevsw[major(dev)].d_ioctl)(dev, cmd, addr, flag, p);
 105 }
 106
 107
 108 int
 109 cnselect(__unused dev_t dev, int flag, void *wql, struct proc *p)
 110 {
 111         dev = cndev();
 112         return (*cdevsw[major(dev)].d_select)(dev, flag, wql, p);
 113 }