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 */
19int
20prom_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 */
34int
35prom_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. */
47char
48prom_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. */
56void
57prom_putchar(char c)
58{
59	while(prom_nbputchar(c) == -1) ;
60	return;
61}
62
63/* Query for input device type */
64#if 0
65enum prom_input_device
66prom_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" (&current_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
114enum prom_output_device
115prom_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" (&current_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