xref: /openbmc/linux/arch/m68k/sun3x/prom.c (revision 842ed298)
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/segment.h>
18 #include <asm/sun3ints.h>
19 #include <asm/openprom.h>
20 #include <asm/machines.h>
21 
22 void (*sun3x_putchar)(int);
23 int (*sun3x_getchar)(void);
24 int (*sun3x_mayget)(void);
25 int (*sun3x_mayput)(int);
26 void (*sun3x_prom_reboot)(void);
27 e_vector sun3x_prom_abort;
28 struct linux_romvec *romvec;
29 
30 /* prom vector table */
31 e_vector *sun3x_prom_vbr;
32 
33 /* Handle returning to the prom */
34 void sun3x_halt(void)
35 {
36 	unsigned long flags;
37 
38 	/* Disable interrupts while we mess with things */
39 	local_irq_save(flags);
40 
41 	/* Restore prom vbr */
42 	asm volatile ("movec %0,%%vbr" : : "r" ((void*)sun3x_prom_vbr));
43 
44 	/* Restore prom NMI clock */
45 //	sun3x_disable_intreg(5);
46 	sun3_enable_irq(7);
47 
48 	/* Let 'er rip */
49 	asm volatile ("trap #14");
50 
51 	/* Restore everything */
52 	sun3_disable_irq(7);
53 	sun3_enable_irq(5);
54 
55 	asm volatile ("movec %0,%%vbr" : : "r" ((void*)vectors));
56 	local_irq_restore(flags);
57 }
58 
59 void sun3x_reboot(void)
60 {
61 	/* This never returns, don't bother saving things */
62 	local_irq_disable();
63 
64 	/* Restore prom vbr */
65 	asm volatile ("movec %0,%%vbr" : : "r" ((void*)sun3x_prom_vbr));
66 
67 	/* Restore prom NMI clock */
68 	sun3_disable_irq(5);
69 	sun3_enable_irq(7);
70 
71 	/* Let 'er rip */
72 	(*romvec->pv_reboot)("vmlinux");
73 }
74 
75 static void sun3x_prom_write(struct console *co, const char *s,
76                              unsigned int count)
77 {
78 	while (count--) {
79 		if (*s == '\n')
80 			sun3x_putchar('\r');
81 		sun3x_putchar(*s++);
82 	}
83 }
84 
85 /* debug console - write-only */
86 
87 static struct console sun3x_debug = {
88 	.name	= "debug",
89 	.write	= sun3x_prom_write,
90 	.flags	= CON_PRINTBUFFER,
91 	.index	= -1,
92 };
93 
94 void __init sun3x_prom_init(void)
95 {
96 	/* Read the vector table */
97 
98 	sun3x_putchar = *(void (**)(int)) (SUN3X_P_PUTCHAR);
99 	sun3x_getchar = *(int (**)(void)) (SUN3X_P_GETCHAR);
100 	sun3x_mayget = *(int (**)(void))  (SUN3X_P_MAYGET);
101 	sun3x_mayput = *(int (**)(int))   (SUN3X_P_MAYPUT);
102 	sun3x_prom_reboot = *(void (**)(void)) (SUN3X_P_REBOOT);
103 	sun3x_prom_abort = *(e_vector *)  (SUN3X_P_ABORT);
104 	romvec = (struct linux_romvec *)SUN3X_PROM_BASE;
105 
106 	idprom_init();
107 
108 	if (!((idprom->id_machtype & SM_ARCH_MASK) == SM_SUN3X)) {
109 		pr_warn("Machine reports strange type %02x\n",
110 			idprom->id_machtype);
111 		pr_warn("Pretending it's a 3/80, but very afraid...\n");
112 		idprom->id_machtype = SM_SUN3X | SM_3_80;
113 	}
114 
115 	/* point trap #14 at abort.
116 	 * XXX this is futile since we restore the vbr first - oops
117 	 */
118 	vectors[VEC_TRAP14] = sun3x_prom_abort;
119 }
120 
121 static int __init sun3x_debug_setup(char *arg)
122 {
123 	/* If debug=prom was specified, start the debug console */
124 	if (MACH_IS_SUN3X && !strcmp(arg, "prom"))
125 		register_console(&sun3x_debug);
126 	return 0;
127 }
128 
129 early_param("debug", sun3x_debug_setup);
130 
131 /* some prom functions to export */
132 int prom_getintdefault(int node, char *property, int deflt)
133 {
134 	return deflt;
135 }
136 
137 int prom_getbool (int node, char *prop)
138 {
139 	return 1;
140 }
141 
142 void prom_printf(char *fmt, ...)
143 {
144 }
145 
146 void prom_halt (void)
147 {
148 	sun3x_halt();
149 }
150 
151 /* Get the idprom and stuff it into buffer 'idbuf'.  Returns the
152  * format type.  'num_bytes' is the number of bytes that your idbuf
153  * has space for.  Returns 0xff on error.
154  */
155 unsigned char
156 prom_get_idprom(char *idbuf, int num_bytes)
157 {
158         int i;
159 
160 	/* make a copy of the idprom structure */
161 	for (i = 0; i < num_bytes; i++)
162 		idbuf[i] = ((char *)SUN3X_IDPROM)[i];
163 
164         return idbuf[0];
165 }
166