1 /* 2 * Copyright (C) 2006-2007 PA Semi, Inc 3 * 4 * Maintained by: Olof Johansson <olof@lixom.net> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 * 19 */ 20 21 #undef DEBUG 22 23 #include <linux/kernel.h> 24 #include <linux/string.h> 25 #include <linux/irq.h> 26 27 #include <asm/machdep.h> 28 #include <asm/reg.h> 29 #include <asm/smp.h> 30 31 #include "pasemi.h" 32 33 struct sleep_mode { 34 char *name; 35 void (*entry)(void); 36 }; 37 38 static struct sleep_mode modes[] = { 39 { .name = "spin", .entry = &idle_spin }, 40 { .name = "doze", .entry = &idle_doze }, 41 }; 42 43 static int current_mode = 0; 44 45 static int pasemi_system_reset_exception(struct pt_regs *regs) 46 { 47 /* If we were woken up from power savings, we need to return 48 * to the calling function, since nip is not saved across 49 * all modes. 50 */ 51 52 if (regs->msr & SRR1_WAKEMASK) 53 regs->nip = regs->link; 54 55 switch (regs->msr & SRR1_WAKEMASK) { 56 case SRR1_WAKEDEC: 57 set_dec(1); 58 case SRR1_WAKEEE: 59 /* 60 * Handle these when interrupts get re-enabled and we take 61 * them as regular exceptions. We are in an NMI context 62 * and can't handle these here. 63 */ 64 break; 65 default: 66 /* do system reset */ 67 return 0; 68 } 69 70 /* Set higher astate since we come out of power savings at 0 */ 71 restore_astate(hard_smp_processor_id()); 72 73 /* everything handled */ 74 regs->msr |= MSR_RI; 75 return 1; 76 } 77 78 static int __init pasemi_idle_init(void) 79 { 80 #ifndef CONFIG_PPC_PASEMI_CPUFREQ 81 pr_warn("No cpufreq driver, powersavings modes disabled\n"); 82 current_mode = 0; 83 #endif 84 85 ppc_md.system_reset_exception = pasemi_system_reset_exception; 86 ppc_md.power_save = modes[current_mode].entry; 87 pr_info("Using PA6T idle loop (%s)\n", modes[current_mode].name); 88 89 return 0; 90 } 91 machine_late_initcall(pasemi, pasemi_idle_init); 92 93 static int __init idle_param(char *p) 94 { 95 int i; 96 for (i = 0; i < ARRAY_SIZE(modes); i++) { 97 if (!strcmp(modes[i].name, p)) { 98 current_mode = i; 99 break; 100 } 101 } 102 return 0; 103 } 104 105 early_param("idle", idle_param); 106