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/sun3ints.h>
  18 #include <asm/openprom.h>
  19 #include <asm/machines.h>
  20
  21 void (*sun3x_putchar)(int);
  22 int (*sun3x_getchar)(void);
  23 int (*sun3x_mayget)(void);
  24 int (*sun3x_mayput)(int);
  25 void (*sun3x_prom_reboot)(void);
  26 e_vector sun3x_prom_abort;
  27 struct linux_romvec *romvec;
  28
  29 /* prom vector table */
  30 e_vector *sun3x_prom_vbr;
  31
  32 /* Handle returning to the prom */
  33 static 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
  58 void 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
  74 static 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
  86 static struct console sun3x_debug = {
  87         .name   = "debug",
  88         .write  = sun3x_prom_write,
  89         .flags  = CON_PRINTBUFFER,
  90         .index  = -1,
  91 };
  92
  93 void __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
 120 static 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
 128 early_param("debug", sun3x_debug_setup);
 129
 130 /* some prom functions to export */
 131 int prom_getintdefault(int node, char *property, int deflt)
 132 {
 133         return deflt;
 134 }
 135
 136 int prom_getbool (int node, char *prop)
 137 {
 138         return 1;
 139 }
 140
 141 void prom_printf(char *fmt, ...)
 142 {
 143 }
 144
 145 void 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  */
 154 unsigned char
 155 prom_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 }