LXR linux/arch/mips/lantiq/falcon/reset.c

   1/*
   2 * This program is free software; you can redistribute it and/or modify it
   3 * under the terms of the GNU General Public License version 2 as published
   4 * by the Free Software Foundation.
   5 *
   6 * Copyright (C) 2012 Thomas Langer <thomas.langer@lantiq.com>
   7 * Copyright (C) 2012 John Crispin <john@phrozen.org>
   8 */
   9
  10#include <linux/init.h>
  11#include <linux/io.h>
  12#include <linux/pm.h>
  13#include <asm/reboot.h>
  14#include <linux/export.h>
  15
  16#include <lantiq_soc.h>
  17
  18/* CPU0 Reset Source Register */
  19#define SYS1_CPU0RS             0x0040
  20/* reset cause mask */
  21#define CPU0RS_MASK             0x0003
  22/* CPU0 Boot Mode Register */
  23#define SYS1_BM                 0x00a0
  24/* boot mode mask */
  25#define BM_MASK                 0x0005
  26
  27/* allow platform code to find out what surce we booted from */
  28unsigned char ltq_boot_select(void)
  29{
  30        return ltq_sys1_r32(SYS1_BM) & BM_MASK;
  31}
  32
  33/* allow the watchdog driver to find out what the boot reason was */
  34int ltq_reset_cause(void)
  35{
  36        return ltq_sys1_r32(SYS1_CPU0RS) & CPU0RS_MASK;
  37}
  38EXPORT_SYMBOL_GPL(ltq_reset_cause);
  39
  40#define BOOT_REG_BASE   (KSEG1 | 0x1F200000)
  41#define BOOT_PW1_REG    (BOOT_REG_BASE | 0x20)
  42#define BOOT_PW2_REG    (BOOT_REG_BASE | 0x24)
  43#define BOOT_PW1        0x4C545100
  44#define BOOT_PW2        0x0051544C
  45
  46#define WDT_REG_BASE    (KSEG1 | 0x1F8803F0)
  47#define WDT_PW1         0x00BE0000
  48#define WDT_PW2         0x00DC0000
  49
  50static void machine_restart(char *command)
  51{
  52        local_irq_disable();
  53
  54        /* reboot magic */
  55        ltq_w32(BOOT_PW1, (void *)BOOT_PW1_REG); /* 'LTQ\0' */
  56        ltq_w32(BOOT_PW2, (void *)BOOT_PW2_REG); /* '\0QTL' */
  57        ltq_w32(0, (void *)BOOT_REG_BASE); /* reset Bootreg RVEC */
  58
  59        /* watchdog magic */
  60        ltq_w32(WDT_PW1, (void *)WDT_REG_BASE);
  61        ltq_w32(WDT_PW2 |
  62                (0x3 << 26) | /* PWL */
  63                (0x2 << 24) | /* CLKDIV */
  64                (0x1 << 31) | /* enable */
  65                (1), /* reload */
  66                (void *)WDT_REG_BASE);
  67        unreachable();
  68}
  69
  70static void machine_halt(void)
  71{
  72        local_irq_disable();
  73        unreachable();
  74}
  75
  76static void machine_power_off(void)
  77{
  78        local_irq_disable();
  79        unreachable();
  80}
  81
  82static int __init mips_reboot_setup(void)
  83{
  84        _machine_restart = machine_restart;
  85        _machine_halt = machine_halt;
  86        pm_power_off = machine_power_off;
  87        return 0;
  88}
  89
  90arch_initcall(mips_reboot_setup);
  91