LXR linux/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 */
  18static 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 ...  */
  28void 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
  45void sni_machine_power_off(void)
  46{
  47        *(volatile unsigned char *)PCIMT_CSWCSM = 0xfd;
  48}
  49