1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2006-2007 PA Semi, Inc 4 * 5 * Maintained by: Olof Johansson <olof@lixom.net> 6 */ 7 8 #undef DEBUG 9 10 #include <linux/kernel.h> 11 #include <linux/string.h> 12 #include <linux/irq.h> 13 14 #include <asm/machdep.h> 15 #include <asm/reg.h> 16 #include <asm/smp.h> 17 18 #include "pasemi.h" 19 20 struct sleep_mode { 21 char *name; 22 void (*entry)(void); 23 }; 24 25 static struct sleep_mode modes[] = { 26 { .name = "spin", .entry = &idle_spin }, 27 { .name = "doze", .entry = &idle_doze }, 28 }; 29 30 static int current_mode = 0; 31 32 static int pasemi_system_reset_exception(struct pt_regs *regs) 33 { 34 /* If we were woken up from power savings, we need to return 35 * to the calling function, since nip is not saved across 36 * all modes. 37 */ 38 39 if (regs->msr & SRR1_WAKEMASK) 40 regs_set_return_ip(regs, regs->link); 41 42 switch (regs->msr & SRR1_WAKEMASK) { 43 case SRR1_WAKEDEC: 44 set_dec(1); 45 break; 46 case SRR1_WAKEEE: 47 /* 48 * Handle these when interrupts get re-enabled and we take 49 * them as regular exceptions. We are in an NMI context 50 * and can't handle these here. 51 */ 52 break; 53 default: 54 /* do system reset */ 55 return 0; 56 } 57 58 /* Set higher astate since we come out of power savings at 0 */ 59 restore_astate(hard_smp_processor_id()); 60 61 /* everything handled */ 62 regs_set_recoverable(regs); 63 return 1; 64 } 65 66 static int __init pasemi_idle_init(void) 67 { 68 #ifndef CONFIG_PPC_PASEMI_CPUFREQ 69 pr_warn("No cpufreq driver, powersavings modes disabled\n"); 70 current_mode = 0; 71 #endif 72 73 ppc_md.system_reset_exception = pasemi_system_reset_exception; 74 ppc_md.power_save = modes[current_mode].entry; 75 pr_info("Using PA6T idle loop (%s)\n", modes[current_mode].name); 76 77 return 0; 78 } 79 machine_late_initcall(pasemi, pasemi_idle_init); 80 81 static int __init idle_param(char *p) 82 { 83 int i; 84 for (i = 0; i < ARRAY_SIZE(modes); i++) { 85 if (!strcmp(modes[i].name, p)) { 86 current_mode = i; 87 break; 88 } 89 } 90 return 0; 91 } 92 93 early_param("idle", idle_param); 94