arch/powerpc/platforms/powernv/opal-power.c

   1 /*
   2  * PowerNV OPAL power control for graceful shutdown handling
   3  *
   4  * Copyright 2015 IBM Corp.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/reboot.h>
  14 #include <linux/notifier.h>
  15
  16 #include <asm/opal.h>
  17 #include <asm/machdep.h>
  18
  19 #define SOFT_OFF 0x00
  20 #define SOFT_REBOOT 0x01
  21
  22 static int opal_power_control_event(struct notifier_block *nb,
  23                                     unsigned long msg_type, void *msg)
  24 {
  25         struct opal_msg *power_msg = msg;
  26         uint64_t type;
  27
  28         type = be64_to_cpu(power_msg->params[0]);
  29
  30         switch (type) {
  31         case SOFT_REBOOT:
  32                 /* Fall through. The service processor is responsible for
  33                  * bringing the machine back up */
  34         case SOFT_OFF:
  35                 pr_info("OPAL: poweroff requested\n");
  36                 orderly_poweroff(true);
  37                 break;
  38         default:
  39                 pr_err("OPAL: power control type unexpected %016llx\n", type);
  40         }
  41
  42         return 0;
  43 }
  44
  45 static struct notifier_block opal_power_control_nb = {
  46         .notifier_call  = opal_power_control_event,
  47         .next           = NULL,
  48         .priority       = 0,
  49 };
  50
  51 static int __init opal_power_control_init(void)
  52 {
  53         int ret;
  54
  55         ret = opal_message_notifier_register(OPAL_MSG_SHUTDOWN,
  56                                              &opal_power_control_nb);
  57         if (ret) {
  58                 pr_err("%s: Can't register OPAL event notifier (%d)\n",
  59                                 __func__, ret);
  60                 return ret;
  61         }
  62
  63         return 0;
  64 }
  65 machine_subsys_initcall(powernv, opal_power_control_init);