1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * console.c: Routines that deal with sending and receiving IO
4 * to/from the current console device using the PROM.
5 *
6 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
7 */
8
9 #include <linux/types.h>
10 #include <linux/kernel.h>
11 #include <linux/sched.h>
12 #include <asm/openprom.h>
13 #include <asm/oplib.h>
14 #include <linux/string.h>
15
16 /* Non blocking get character from console input device, returns -1
17 * if no input was taken. This can be used for polling.
18 */
19 int
20 prom_nbgetchar(void)
21 {
22 int i = -1;
23 unsigned long flags;
24
25 local_irq_save(flags);
26 i = (*(romvec->pv_nbgetchar))();
27 local_irq_restore(flags);
28 return i; /* Ugh, we could spin forever on unsupported proms ;( */
29 }
30
31 /* Non blocking put character to console device, returns -1 if
32 * unsuccessful.
33 */
34 int
35 prom_nbputchar(char c)
36 {
37 unsigned long flags;
38 int i = -1;
39
40 local_irq_save(flags);
41 i = (*(romvec->pv_nbputchar))(c);
42 local_irq_restore(flags);
43 return i; /* Ugh, we could spin forever on unsupported proms ;( */
44 }
45
46 /* Blocking version of get character routine above. */
47 char
48 prom_getchar(void)
49 {
50 int character;
51 while((character = prom_nbgetchar()) == -1) ;
52 return (char) character;
53 }
54
55 /* Blocking version of put character routine above. */
56 void
57 prom_putchar(char c)
58 {
59 while(prom_nbputchar(c) == -1) ;
60 return;
61 }
62
63 /* Query for input device type */
64 #if 0
65 enum prom_input_device
66 prom_query_input_device()
67 {
68 unsigned long flags;
69 int st_p;
70 char propb[64];
71 char *p;
72
73 switch(prom_vers) {
74 case PROM_V0:
75 case PROM_V2:
76 default:
77 switch(*romvec->pv_stdin) {
78 case PROMDEV_KBD: return PROMDEV_IKBD;
79 case PROMDEV_TTYA: return PROMDEV_ITTYA;
80 case PROMDEV_TTYB: return PROMDEV_ITTYB;
81 default:
82 return PROMDEV_I_UNK;
83 };
84 case PROM_V3:
85 case PROM_P1275:
86 local_irq_save(flags);
87 st_p = (*romvec->pv_v2devops.v2_inst2pkg)(*romvec->pv_v2bootargs.fd_stdin);
88 __asm__ __volatile__("ld [%0], %%g6\n\t" : :
89 "r" (¤t_set[smp_processor_id()]) :
90 "memory");
91 local_irq_restore(flags);
92 if(prom_node_has_property(st_p, "keyboard"))
93 return PROMDEV_IKBD;
94 prom_getproperty(st_p, "device_type", propb, sizeof(propb));
95 if(strncmp(propb, "serial", sizeof("serial")))
96 return PROMDEV_I_UNK;
97 prom_getproperty(prom_root_node, "stdin-path", propb, sizeof(propb));
98 p = propb;
99 while(*p) p++; p -= 2;
100 if(p[0] == ':') {
101 if(p[1] == 'a')
102 return PROMDEV_ITTYA;
103 else if(p[1] == 'b')
104 return PROMDEV_ITTYB;
105 }
106 return PROMDEV_I_UNK;
107 };
108 }
109 #endif
110
111 /* Query for output device type */
112
113 #if 0
114 enum prom_output_device
115 prom_query_output_device()
116 {
117 unsigned long flags;
118 int st_p;
119 char propb[64];
120 char *p;
121 int propl;
122
123 switch(prom_vers) {
124 case PROM_V0:
125 switch(*romvec->pv_stdin) {
126 case PROMDEV_SCREEN: return PROMDEV_OSCREEN;
127 case PROMDEV_TTYA: return PROMDEV_OTTYA;
128 case PROMDEV_TTYB: return PROMDEV_OTTYB;
129 };
130 break;
131 case PROM_V2:
132 case PROM_V3:
133 case PROM_P1275:
134 local_irq_save(flags);
135 st_p = (*romvec->pv_v2devops.v2_inst2pkg)(*romvec->pv_v2bootargs.fd_stdout);
136 __asm__ __volatile__("ld [%0], %%g6\n\t" : :
137 "r" (¤t_set[smp_processor_id()]) :
138 "memory");
139 local_irq_restore(flags);
140 propl = prom_getproperty(st_p, "device_type", propb, sizeof(propb));
141 if (propl >= 0 && propl == sizeof("display") &&
142 strncmp("display", propb, sizeof("display")) == 0)
143 {
144 return PROMDEV_OSCREEN;
145 }
146 if(prom_vers == PROM_V3) {
147 if(strncmp("serial", propb, sizeof("serial")))
148 return PROMDEV_O_UNK;
149 prom_getproperty(prom_root_node, "stdout-path", propb, sizeof(propb));
150 p = propb;
151 while(*p) p++; p -= 2;
152 if(p[0]==':') {
153 if(p[1] == 'a')
154 return PROMDEV_OTTYA;
155 else if(p[1] == 'b')
156 return PROMDEV_OTTYB;
157 }
158 return PROMDEV_O_UNK;
159 } else {
160 /* This works on SS-2 (an early OpenFirmware) still. */
161 switch(*romvec->pv_stdin) {
162 case PROMDEV_TTYA: return PROMDEV_OTTYA;
163 case PROMDEV_TTYB: return PROMDEV_OTTYB;
164 };
165 }
166 break;
167 };
168 return PROMDEV_O_UNK;
169 }
170 #endif
171
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