|  | /* 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@davemloft.net) | 
|  | * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) | 
|  | */ | 
|  |  | 
|  | #include <linux/types.h> | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/sched.h> | 
|  | #include <asm/openprom.h> | 
|  | #include <asm/oplib.h> | 
|  | #include <asm/system.h> | 
|  | #include <linux/string.h> | 
|  |  | 
|  | extern int prom_stdin, prom_stdout; | 
|  |  | 
|  | /* Non blocking get character from console input device, returns -1 | 
|  | * if no input was taken.  This can be used for polling. | 
|  | */ | 
|  | inline int | 
|  | prom_nbgetchar(void) | 
|  | { | 
|  | char inc; | 
|  |  | 
|  | if (p1275_cmd("read", P1275_ARG(1,P1275_ARG_OUT_BUF)| | 
|  | P1275_INOUT(3,1), | 
|  | prom_stdin, &inc, P1275_SIZE(1)) == 1) | 
|  | return inc; | 
|  | else | 
|  | return -1; | 
|  | } | 
|  |  | 
|  | /* Non blocking put character to console device, returns -1 if | 
|  | * unsuccessful. | 
|  | */ | 
|  | inline int | 
|  | prom_nbputchar(char c) | 
|  | { | 
|  | char outc; | 
|  |  | 
|  | outc = c; | 
|  | if (p1275_cmd("write", P1275_ARG(1,P1275_ARG_IN_BUF)| | 
|  | P1275_INOUT(3,1), | 
|  | prom_stdout, &outc, P1275_SIZE(1)) == 1) | 
|  | return 0; | 
|  | else | 
|  | return -1; | 
|  | } | 
|  |  | 
|  | /* 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) | 
|  | { | 
|  | prom_nbputchar(c); | 
|  | } | 
|  |  | 
|  | void | 
|  | prom_puts(const char *s, int len) | 
|  | { | 
|  | p1275_cmd("write", P1275_ARG(1,P1275_ARG_IN_BUF)| | 
|  | P1275_INOUT(3,1), | 
|  | prom_stdout, s, P1275_SIZE(len)); | 
|  | } |