arch/mips/sni/reset.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/arch/mips/sni/process.c
   4  *
   5  *  Reset a SNI machine.
   6  */
   7 #include <linux/delay.h>
   8
   9 #include <asm/io.h>
  10 #include <asm/reboot.h>
  11 #include <asm/sni.h>
  12
  13 /*
  14  * This routine reboots the machine by asking the keyboard
  15  * controller to pulse the reset-line low. We try that for a while,
  16  * and if it doesn't work, we do some other stupid things.
  17  */
  18 static inline void kb_wait(void)
  19 {
  20         int i;
  21
  22         for (i = 0; i < 0x10000; i++)
  23                 if ((inb_p(0x64) & 0x02) == 0)
  24                         break;
  25 }
  26
  27 /* XXX This ends up at the ARC firmware prompt ...  */
  28 void sni_machine_restart(char *command)
  29 {
  30         int i;
  31
  32         /* This does a normal via the keyboard controller like a PC.
  33            We can do that easier ...  */
  34         local_irq_disable();
  35         for (;;) {
  36                 for (i = 0; i < 100; i++) {
  37                         kb_wait();
  38                         udelay(50);
  39                         outb_p(0xfe, 0x64);      /* pulse reset low */
  40                         udelay(50);
  41                 }
  42         }
  43 }
  44
  45 void sni_machine_power_off(void)
  46 {
  47         *(volatile unsigned char *)PCIMT_CSWCSM = 0xfd;
  48 }