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/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 }