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_WAKEEE: 57 do_IRQ(regs); 58 break; 59 case SRR1_WAKEDEC: 60 timer_interrupt(regs); 61 break; 62 default: 63 /* do system reset */ 64 return 0; 65 } 66 67 /* Set higher astate since we come out of power savings at 0 */ 68 restore_astate(hard_smp_processor_id()); 69 70 /* everything handled */ 71 regs->msr |= MSR_RI; 72 return 1; 73 } 74 75 static int __init pasemi_idle_init(void) 76 { 77 #ifndef CONFIG_PPC_PASEMI_CPUFREQ 78 printk(KERN_WARNING "No cpufreq driver, powersavings modes disabled\n"); 79 current_mode = 0; 80 #endif 81 82 ppc_md.system_reset_exception = pasemi_system_reset_exception; 83 ppc_md.power_save = modes[current_mode].entry; 84 printk(KERN_INFO "Using PA6T idle loop (%s)\n", modes[current_mode].name); 85 86 return 0; 87 } 88 machine_late_initcall(pasemi, pasemi_idle_init); 89 90 static int __init idle_param(char *p) 91 { 92 int i; 93 for (i = 0; i < ARRAY_SIZE(modes); i++) { 94 if (!strcmp(modes[i].name, p)) { 95 current_mode = i; 96 break; 97 } 98 } 99 return 0; 100 } 101 102 early_param("idle", idle_param); 103