1// SPDX-License-Identifier: GPL-2.0
2/* Prom access routines for the sun3x */
3
4#include <linux/types.h>
5#include <linux/kernel.h>
6#include <linux/tty.h>
7#include <linux/console.h>
8#include <linux/init.h>
9#include <linux/mm.h>
10#include <linux/string.h>
11
12#include <asm/page.h>
13#include <asm/setup.h>
14#include <asm/traps.h>
15#include <asm/sun3xprom.h>
16#include <asm/idprom.h>
17#include <asm/sun3ints.h>
18#include <asm/openprom.h>
19#include <asm/machines.h>
20
21void (*sun3x_putchar)(int);
22int (*sun3x_getchar)(void);
23int (*sun3x_mayget)(void);
24int (*sun3x_mayput)(int);
25void (*sun3x_prom_reboot)(void);
26e_vector sun3x_prom_abort;
27struct linux_romvec *romvec;
28
29/* prom vector table */
30e_vector *sun3x_prom_vbr;
31
32/* Handle returning to the prom */
33static void sun3x_halt(void)
34{
35	unsigned long flags;
36
37	/* Disable interrupts while we mess with things */
38	local_irq_save(flags);
39
40	/* Restore prom vbr */
41	asm volatile ("movec %0,%%vbr" : : "r" ((void*)sun3x_prom_vbr));
42
43	/* Restore prom NMI clock */
44//	sun3x_disable_intreg(5);
45	sun3_enable_irq(7);
46
47	/* Let 'er rip */
48	asm volatile ("trap #14");
49
50	/* Restore everything */
51	sun3_disable_irq(7);
52	sun3_enable_irq(5);
53
54	asm volatile ("movec %0,%%vbr" : : "r" ((void*)vectors));
55	local_irq_restore(flags);
56}
57
58void sun3x_reboot(void)
59{
60	/* This never returns, don't bother saving things */
61	local_irq_disable();
62
63	/* Restore prom vbr */
64	asm volatile ("movec %0,%%vbr" : : "r" ((void*)sun3x_prom_vbr));
65
66	/* Restore prom NMI clock */
67	sun3_disable_irq(5);
68	sun3_enable_irq(7);
69
70	/* Let 'er rip */
71	(*romvec->pv_reboot)("vmlinux");
72}
73
74static void sun3x_prom_write(struct console *co, const char *s,
75                             unsigned int count)
76{
77	while (count--) {
78		if (*s == '\n')
79			sun3x_putchar('\r');
80		sun3x_putchar(*s++);
81	}
82}
83
84/* debug console - write-only */
85
86static struct console sun3x_debug = {
87	.name	= "debug",
88	.write	= sun3x_prom_write,
89	.flags	= CON_PRINTBUFFER,
90	.index	= -1,
91};
92
93void __init sun3x_prom_init(void)
94{
95	/* Read the vector table */
96
97	sun3x_putchar = *(void (**)(int)) (SUN3X_P_PUTCHAR);
98	sun3x_getchar = *(int (**)(void)) (SUN3X_P_GETCHAR);
99	sun3x_mayget = *(int (**)(void))  (SUN3X_P_MAYGET);
100	sun3x_mayput = *(int (**)(int))   (SUN3X_P_MAYPUT);
101	sun3x_prom_reboot = *(void (**)(void)) (SUN3X_P_REBOOT);
102	sun3x_prom_abort = *(e_vector *)  (SUN3X_P_ABORT);
103	romvec = (struct linux_romvec *)SUN3X_PROM_BASE;
104
105	idprom_init();
106
107	if (!((idprom->id_machtype & SM_ARCH_MASK) == SM_SUN3X)) {
108		pr_warn("Machine reports strange type %02x\n",
109			idprom->id_machtype);
110		pr_warn("Pretending it's a 3/80, but very afraid...\n");
111		idprom->id_machtype = SM_SUN3X | SM_3_80;
112	}
113
114	/* point trap #14 at abort.
115	 * XXX this is futile since we restore the vbr first - oops
116	 */
117	vectors[VEC_TRAP14] = sun3x_prom_abort;
118}
119
120static int __init sun3x_debug_setup(char *arg)
121{
122	/* If debug=prom was specified, start the debug console */
123	if (MACH_IS_SUN3X && !strcmp(arg, "prom"))
124		register_console(&sun3x_debug);
125	return 0;
126}
127
128early_param("debug", sun3x_debug_setup);
129
130/* some prom functions to export */
131int prom_getintdefault(int node, char *property, int deflt)
132{
133	return deflt;
134}
135
136int prom_getbool (int node, char *prop)
137{
138	return 1;
139}
140
141void prom_printf(char *fmt, ...)
142{
143}
144
145void prom_halt (void)
146{
147	sun3x_halt();
148}
149
150/* Get the idprom and stuff it into buffer 'idbuf'.  Returns the
151 * format type.  'num_bytes' is the number of bytes that your idbuf
152 * has space for.  Returns 0xff on error.
153 */
154unsigned char
155prom_get_idprom(char *idbuf, int num_bytes)
156{
157        int i;
158
159	/* make a copy of the idprom structure */
160	for (i = 0; i < num_bytes; i++)
161		idbuf[i] = ((char *)SUN3X_IDPROM)[i];
162
163        return idbuf[0];
164}
165