| // 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); |