1 /* 2 * arch/sh/kernel/cpu/shmobile/cpuidle.c 3 * 4 * Cpuidle support code for SuperH Mobile 5 * 6 * Copyright (C) 2009 Magnus Damm 7 * 8 * This file is subject to the terms and conditions of the GNU General Public 9 * License. See the file "COPYING" in the main directory of this archive 10 * for more details. 11 */ 12 #include <linux/init.h> 13 #include <linux/kernel.h> 14 #include <linux/io.h> 15 #include <linux/suspend.h> 16 #include <linux/cpuidle.h> 17 #include <linux/export.h> 18 #include <asm/suspend.h> 19 #include <linux/uaccess.h> 20 21 static unsigned long cpuidle_mode[] = { 22 SUSP_SH_SLEEP, /* regular sleep mode */ 23 SUSP_SH_SLEEP | SUSP_SH_SF, /* sleep mode + self refresh */ 24 SUSP_SH_STANDBY | SUSP_SH_SF, /* software standby mode + self refresh */ 25 }; 26 27 static int cpuidle_sleep_enter(struct cpuidle_device *dev, 28 struct cpuidle_driver *drv, 29 int index) 30 { 31 unsigned long allowed_mode = SUSP_SH_SLEEP; 32 int requested_state = index; 33 int allowed_state; 34 int k; 35 36 /* convert allowed mode to allowed state */ 37 for (k = ARRAY_SIZE(cpuidle_mode) - 1; k > 0; k--) 38 if (cpuidle_mode[k] == allowed_mode) 39 break; 40 41 allowed_state = k; 42 43 /* take the following into account for sleep mode selection: 44 * - allowed_state: best mode allowed by hardware (clock deps) 45 * - requested_state: best mode allowed by software (latencies) 46 */ 47 k = min_t(int, allowed_state, requested_state); 48 49 sh_mobile_call_standby(cpuidle_mode[k]); 50 51 return k; 52 } 53 54 static struct cpuidle_driver cpuidle_driver = { 55 .name = "sh_idle", 56 .owner = THIS_MODULE, 57 .states = { 58 { 59 .exit_latency = 1, 60 .target_residency = 1 * 2, 61 .power_usage = 3, 62 .enter = cpuidle_sleep_enter, 63 .name = "C1", 64 .desc = "SuperH Sleep Mode", 65 }, 66 { 67 .exit_latency = 100, 68 .target_residency = 1 * 2, 69 .power_usage = 1, 70 .enter = cpuidle_sleep_enter, 71 .name = "C2", 72 .desc = "SuperH Sleep Mode [SF]", 73 .disabled = true, 74 }, 75 { 76 .exit_latency = 2300, 77 .target_residency = 1 * 2, 78 .power_usage = 1, 79 .enter = cpuidle_sleep_enter, 80 .name = "C3", 81 .desc = "SuperH Mobile Standby Mode [SF]", 82 .disabled = true, 83 }, 84 }, 85 .safe_state_index = 0, 86 .state_count = 3, 87 }; 88 89 int __init sh_mobile_setup_cpuidle(void) 90 { 91 if (sh_mobile_sleep_supported & SUSP_SH_SF) 92 cpuidle_driver.states[1].disabled = false; 93 94 if (sh_mobile_sleep_supported & SUSP_SH_STANDBY) 95 cpuidle_driver.states[2].disabled = false; 96 97 return cpuidle_register(&cpuidle_driver, NULL); 98 } 99