arch/m68k/sun3x/prom.c

   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 }