acrn-kernel/arch/powerpc/platforms/pasemi/idle.c

93 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2006-2007 PA Semi, Inc
*
* Maintained by: Olof Johansson <olof@lixom.net>
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/irq.h>
#include <asm/machdep.h>
#include <asm/reg.h>
#include <asm/smp.h>
#include "pasemi.h"
struct sleep_mode {
char *name;
void (*entry)(void);
};
static struct sleep_mode modes[] = {
{ .name = "spin", .entry = &idle_spin },
{ .name = "doze", .entry = &idle_doze },
};
static int current_mode = 0;
static int pasemi_system_reset_exception(struct pt_regs *regs)
{
/* If we were woken up from power savings, we need to return
* to the calling function, since nip is not saved across
* all modes.
*/
if (regs->msr & SRR1_WAKEMASK)
regs->nip = regs->link;
switch (regs->msr & SRR1_WAKEMASK) {
case SRR1_WAKEDEC:
set_dec(1);
case SRR1_WAKEEE:
/*
* Handle these when interrupts get re-enabled and we take
* them as regular exceptions. We are in an NMI context
* and can't handle these here.
*/
break;
default:
/* do system reset */
return 0;
}
/* Set higher astate since we come out of power savings at 0 */
restore_astate(hard_smp_processor_id());
/* everything handled */
regs->msr |= MSR_RI;
return 1;
}
static int __init pasemi_idle_init(void)
{
#ifndef CONFIG_PPC_PASEMI_CPUFREQ
pr_warn("No cpufreq driver, powersavings modes disabled\n");
current_mode = 0;
#endif
ppc_md.system_reset_exception = pasemi_system_reset_exception;
ppc_md.power_save = modes[current_mode].entry;
pr_info("Using PA6T idle loop (%s)\n", modes[current_mode].name);
return 0;
}
machine_late_initcall(pasemi, pasemi_idle_init);
static int __init idle_param(char *p)
{
int i;
for (i = 0; i < ARRAY_SIZE(modes); i++) {
if (!strcmp(modes[i].name, p)) {
current_mode = i;
break;
}
}
return 0;
}
early_param("idle", idle_param);