kernel_samsung_a34x-permissive/arch/powerpc/platforms/powernv/opal-power.c

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/*
* PowerNV OPAL power control for graceful shutdown handling
*
* Copyright 2015 IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#define pr_fmt(fmt) "opal-power: " fmt
#include <linux/kernel.h>
#include <linux/reboot.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <asm/opal.h>
#include <asm/machdep.h>
#define SOFT_OFF 0x00
#define SOFT_REBOOT 0x01
/* Detect EPOW event */
static bool detect_epow(void)
{
u16 epow;
int i, rc;
__be16 epow_classes;
__be16 opal_epow_status[OPAL_SYSEPOW_MAX] = {0};
/*
* Check for EPOW event. Kernel sends supported EPOW classes info
* to OPAL. OPAL returns EPOW info along with classes present.
*/
epow_classes = cpu_to_be16(OPAL_SYSEPOW_MAX);
rc = opal_get_epow_status(opal_epow_status, &epow_classes);
if (rc != OPAL_SUCCESS) {
pr_err("Failed to get EPOW event information\n");
return false;
}
/* Look for EPOW events present */
for (i = 0; i < be16_to_cpu(epow_classes); i++) {
epow = be16_to_cpu(opal_epow_status[i]);
/* Filter events which do not need shutdown. */
if (i == OPAL_SYSEPOW_POWER)
epow &= ~(OPAL_SYSPOWER_CHNG | OPAL_SYSPOWER_FAIL |
OPAL_SYSPOWER_INCL);
if (epow)
return true;
}
return false;
}
/* Check for existing EPOW, DPO events */
static bool poweroff_pending(void)
{
int rc;
__be64 opal_dpo_timeout;
/* Check for DPO event */
rc = opal_get_dpo_status(&opal_dpo_timeout);
if (rc == OPAL_SUCCESS) {
pr_info("Existing DPO event detected.\n");
return true;
}
/* Check for EPOW event */
if (detect_epow()) {
pr_info("Existing EPOW event detected.\n");
return true;
}
return false;
}
/* OPAL power-control events notifier */
static int opal_power_control_event(struct notifier_block *nb,
unsigned long msg_type, void *msg)
{
uint64_t type;
switch (msg_type) {
case OPAL_MSG_EPOW:
if (detect_epow()) {
pr_info("EPOW msg received. Powering off system\n");
orderly_poweroff(true);
}
break;
case OPAL_MSG_DPO:
pr_info("DPO msg received. Powering off system\n");
orderly_poweroff(true);
break;
case OPAL_MSG_SHUTDOWN:
type = be64_to_cpu(((struct opal_msg *)msg)->params[0]);
switch (type) {
case SOFT_REBOOT:
pr_info("Reboot requested\n");
orderly_reboot();
break;
case SOFT_OFF:
pr_info("Poweroff requested\n");
orderly_poweroff(true);
break;
default:
pr_err("Unknown power-control type %llu\n", type);
}
break;
default:
pr_err("Unknown OPAL message type %lu\n", msg_type);
}
return 0;
}
/* OPAL EPOW event notifier block */
static struct notifier_block opal_epow_nb = {
.notifier_call = opal_power_control_event,
.next = NULL,
.priority = 0,
};
/* OPAL DPO event notifier block */
static struct notifier_block opal_dpo_nb = {
.notifier_call = opal_power_control_event,
.next = NULL,
.priority = 0,
};
/* OPAL power-control event notifier block */
static struct notifier_block opal_power_control_nb = {
.notifier_call = opal_power_control_event,
.next = NULL,
.priority = 0,
};
static int __init opal_power_control_init(void)
{
int ret, supported = 0;
struct device_node *np;
/* Register OPAL power-control events notifier */
ret = opal_message_notifier_register(OPAL_MSG_SHUTDOWN,
&opal_power_control_nb);
if (ret)
pr_err("Failed to register SHUTDOWN notifier, ret = %d\n", ret);
/* Determine OPAL EPOW, DPO support */
np = of_find_node_by_path("/ibm,opal/epow");
if (np) {
supported = of_device_is_compatible(np, "ibm,opal-v3-epow");
of_node_put(np);
}
if (!supported)
return 0;
pr_info("OPAL EPOW, DPO support detected.\n");
/* Register EPOW event notifier */
ret = opal_message_notifier_register(OPAL_MSG_EPOW, &opal_epow_nb);
if (ret)
pr_err("Failed to register EPOW notifier, ret = %d\n", ret);
/* Register DPO event notifier */
ret = opal_message_notifier_register(OPAL_MSG_DPO, &opal_dpo_nb);
if (ret)
pr_err("Failed to register DPO notifier, ret = %d\n", ret);
/* Check for any pending EPOW or DPO events. */
if (poweroff_pending())
orderly_poweroff(true);
return 0;
}
machine_subsys_initcall(powernv, opal_power_control_init);