1 /* console.c: Routines that deal with sending and receiving IO 2 * to/from the current console device using the PROM. 3 * 4 * Copyright (C) 1995 David S. Miller (davem@davemloft.net) 5 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) 6 */ 7 8 #include <linux/types.h> 9 #include <linux/kernel.h> 10 #include <linux/sched.h> 11 #include <asm/openprom.h> 12 #include <asm/oplib.h> 13 #include <asm/system.h> 14 #include <linux/string.h> 15 16 extern int prom_stdin, prom_stdout; 17 18 /* Non blocking get character from console input device, returns -1 19 * if no input was taken. This can be used for polling. 20 */ 21 inline int 22 prom_nbgetchar(void) 23 { 24 unsigned long args[7]; 25 char inc; 26 27 args[0] = (unsigned long) "read"; 28 args[1] = 3; 29 args[2] = 1; 30 args[3] = (unsigned int) prom_stdin; 31 args[4] = (unsigned long) &inc; 32 args[5] = 1; 33 args[6] = (unsigned long) -1; 34 35 p1275_cmd_direct(args); 36 37 if (args[6] == 1) 38 return inc; 39 return -1; 40 } 41 42 /* Non blocking put character to console device, returns -1 if 43 * unsuccessful. 44 */ 45 inline int 46 prom_nbputchar(char c) 47 { 48 unsigned long args[7]; 49 char outc; 50 51 outc = c; 52 53 args[0] = (unsigned long) "write"; 54 args[1] = 3; 55 args[2] = 1; 56 args[3] = (unsigned int) prom_stdout; 57 args[4] = (unsigned long) &outc; 58 args[5] = 1; 59 args[6] = (unsigned long) -1; 60 61 p1275_cmd_direct(args); 62 63 if (args[6] == 1) 64 return 0; 65 else 66 return -1; 67 } 68 69 /* Blocking version of get character routine above. */ 70 char 71 prom_getchar(void) 72 { 73 int character; 74 while((character = prom_nbgetchar()) == -1) ; 75 return (char) character; 76 } 77 78 /* Blocking version of put character routine above. */ 79 void 80 prom_putchar(char c) 81 { 82 prom_nbputchar(c); 83 } 84