xref: /linux/arch/m68k/sun3x/prom.c (revision ca64d84e93762f4e587e040a44ad9f6089afc777)
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/pgtable.h>
14 #include <asm/setup.h>
15 #include <asm/traps.h>
16 #include <asm/sun3xprom.h>
17 #include <asm/idprom.h>
18 #include <asm/segment.h>
19 #include <asm/sun3ints.h>
20 #include <asm/openprom.h>
21 #include <asm/machines.h>
22 
23 void (*sun3x_putchar)(int);
24 int (*sun3x_getchar)(void);
25 int (*sun3x_mayget)(void);
26 int (*sun3x_mayput)(int);
27 void (*sun3x_prom_reboot)(void);
28 e_vector sun3x_prom_abort;
29 struct linux_romvec *romvec;
30 
31 /* prom vector table */
32 e_vector *sun3x_prom_vbr;
33 
34 /* Handle returning to the prom */
35 void sun3x_halt(void)
36 {
37 	unsigned long flags;
38 
39 	/* Disable interrupts while we mess with things */
40 	local_irq_save(flags);
41 
42 	/* Restore prom vbr */
43 	asm volatile ("movec %0,%%vbr" : : "r" ((void*)sun3x_prom_vbr));
44 
45 	/* Restore prom NMI clock */
46 //	sun3x_disable_intreg(5);
47 	sun3_enable_irq(7);
48 
49 	/* Let 'er rip */
50 	asm volatile ("trap #14");
51 
52 	/* Restore everything */
53 	sun3_disable_irq(7);
54 	sun3_enable_irq(5);
55 
56 	asm volatile ("movec %0,%%vbr" : : "r" ((void*)vectors));
57 	local_irq_restore(flags);
58 }
59 
60 void sun3x_reboot(void)
61 {
62 	/* This never returns, don't bother saving things */
63 	local_irq_disable();
64 
65 	/* Restore prom vbr */
66 	asm volatile ("movec %0,%%vbr" : : "r" ((void*)sun3x_prom_vbr));
67 
68 	/* Restore prom NMI clock */
69 	sun3_disable_irq(5);
70 	sun3_enable_irq(7);
71 
72 	/* Let 'er rip */
73 	(*romvec->pv_reboot)("vmlinux");
74 }
75 
76 static void sun3x_prom_write(struct console *co, const char *s,
77                              unsigned int count)
78 {
79 	while (count--) {
80 		if (*s == '\n')
81 			sun3x_putchar('\r');
82 		sun3x_putchar(*s++);
83 	}
84 }
85 
86 /* debug console - write-only */
87 
88 static struct console sun3x_debug = {
89 	.name	= "debug",
90 	.write	= sun3x_prom_write,
91 	.flags	= CON_PRINTBUFFER,
92 	.index	= -1,
93 };
94 
95 void __init sun3x_prom_init(void)
96 {
97 	/* Read the vector table */
98 
99 	sun3x_putchar = *(void (**)(int)) (SUN3X_P_PUTCHAR);
100 	sun3x_getchar = *(int (**)(void)) (SUN3X_P_GETCHAR);
101 	sun3x_mayget = *(int (**)(void))  (SUN3X_P_MAYGET);
102 	sun3x_mayput = *(int (**)(int))   (SUN3X_P_MAYPUT);
103 	sun3x_prom_reboot = *(void (**)(void)) (SUN3X_P_REBOOT);
104 	sun3x_prom_abort = *(e_vector *)  (SUN3X_P_ABORT);
105 	romvec = (struct linux_romvec *)SUN3X_PROM_BASE;
106 
107 	idprom_init();
108 
109 	if (!((idprom->id_machtype & SM_ARCH_MASK) == SM_SUN3X)) {
110 		pr_warn("Machine reports strange type %02x\n",
111 			idprom->id_machtype);
112 		pr_warn("Pretending it's a 3/80, but very afraid...\n");
113 		idprom->id_machtype = SM_SUN3X | SM_3_80;
114 	}
115 
116 	/* point trap #14 at abort.
117 	 * XXX this is futile since we restore the vbr first - oops
118 	 */
119 	vectors[VEC_TRAP14] = sun3x_prom_abort;
120 }
121 
122 static int __init sun3x_debug_setup(char *arg)
123 {
124 	/* If debug=prom was specified, start the debug console */
125 	if (MACH_IS_SUN3X && !strcmp(arg, "prom"))
126 		register_console(&sun3x_debug);
127 	return 0;
128 }
129 
130 early_param("debug", sun3x_debug_setup);
131 
132 /* some prom functions to export */
133 int prom_getintdefault(int node, char *property, int deflt)
134 {
135 	return deflt;
136 }
137 
138 int prom_getbool (int node, char *prop)
139 {
140 	return 1;
141 }
142 
143 void prom_printf(char *fmt, ...)
144 {
145 }
146 
147 void prom_halt (void)
148 {
149 	sun3x_halt();
150 }
151 
152 /* Get the idprom and stuff it into buffer 'idbuf'.  Returns the
153  * format type.  'num_bytes' is the number of bytes that your idbuf
154  * has space for.  Returns 0xff on error.
155  */
156 unsigned char
157 prom_get_idprom(char *idbuf, int num_bytes)
158 {
159         int i;
160 
161 	/* make a copy of the idprom structure */
162 	for (i = 0; i < num_bytes; i++)
163 		idbuf[i] = ((char *)SUN3X_IDPROM)[i];
164 
165         return idbuf[0];
166 }
167