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console.c

/* $Id: console.c,v 1.25 2001/10/30 04:54:22 davem Exp $
 * console.c: Routines that deal with sending and receiving IO
 *            to/from the current console device using the PROM.
 *
 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 1998 Pete Zaitcev <zaitcev@yahoo.com>
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <asm/openprom.h>
#include <asm/sun4prom.h>
#include <asm/oplib.h>
#include <asm/system.h>
#include <linux/string.h>

extern void restore_current(void);

/* Non blocking get character from console input device, returns -1
 * if no input was taken.  This can be used for polling.
 */
int
prom_nbgetchar(void)
{
      static char inc;
      int i = -1;
      unsigned long flags;

      spin_lock_irqsave(&prom_lock, flags);
      switch(prom_vers) {
      case PROM_V0:
      case PROM_SUN4:
            i = (*(romvec->pv_nbgetchar))();
            break;
      case PROM_V2:
      case PROM_V3:
            if( (*(romvec->pv_v2devops).v2_dev_read)(*romvec->pv_v2bootargs.fd_stdin , &inc, 0x1) == 1) {
                  i = inc;
            } else {
                  i = -1;
            }
            break;
      default:
            i = -1;
            break;
      };
      restore_current();
      spin_unlock_irqrestore(&prom_lock, flags);
      return i; /* Ugh, we could spin forever on unsupported proms ;( */
}

/* Non blocking put character to console device, returns -1 if
 * unsuccessful.
 */
int
prom_nbputchar(char c)
{
      static char outc;
      unsigned long flags;
      int i = -1;

      spin_lock_irqsave(&prom_lock, flags);
      switch(prom_vers) {
      case PROM_V0:
      case PROM_SUN4:
            i = (*(romvec->pv_nbputchar))(c);
            break;
      case PROM_V2:
      case PROM_V3:
            outc = c;
            if( (*(romvec->pv_v2devops).v2_dev_write)(*romvec->pv_v2bootargs.fd_stdout, &outc, 0x1) == 1)
                  i = 0;
            else
                  i = -1;
            break;
      default:
            i = -1;
            break;
      };
      restore_current();
      spin_unlock_irqrestore(&prom_lock, flags);
      return i; /* Ugh, we could spin forever on unsupported proms ;( */
}

/* Blocking version of get character routine above. */
char
prom_getchar(void)
{
      int character;
      while((character = prom_nbgetchar()) == -1) ;
      return (char) character;
}

/* Blocking version of put character routine above. */
void
prom_putchar(char c)
{
      while(prom_nbputchar(c) == -1) ;
      return;
}

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