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 <asm/uaccess.h> 20 #include <asm/hwblk.h> 21 22 static unsigned long cpuidle_mode[] = { 23 SUSP_SH_SLEEP, /* regular sleep mode */ 24 SUSP_SH_SLEEP | SUSP_SH_SF, /* sleep mode + self refresh */ 25 SUSP_SH_STANDBY | SUSP_SH_SF, /* software standby mode + self refresh */ 26 }; 27 28 static int cpuidle_sleep_enter(struct cpuidle_device *dev, 29 struct cpuidle_driver *drv, 30 int index) 31 { 32 unsigned long allowed_mode = arch_hwblk_sleep_mode(); 33 ktime_t before, after; 34 int requested_state = index; 35 int allowed_state; 36 int k; 37 38 /* convert allowed mode to allowed state */ 39 for (k = ARRAY_SIZE(cpuidle_mode) - 1; k > 0; k--) 40 if (cpuidle_mode[k] == allowed_mode) 41 break; 42 43 allowed_state = k; 44 45 /* take the following into account for sleep mode selection: 46 * - allowed_state: best mode allowed by hardware (clock deps) 47 * - requested_state: best mode allowed by software (latencies) 48 */ 49 k = min_t(int, allowed_state, requested_state); 50 51 before = ktime_get(); 52 sh_mobile_call_standby(cpuidle_mode[k]); 53 after = ktime_get(); 54 55 dev->last_residency = (int)ktime_to_ns(ktime_sub(after, before)) >> 10; 56 57 return k; 58 } 59 60 static struct cpuidle_device cpuidle_dev; 61 static struct cpuidle_driver cpuidle_driver = { 62 .name = "sh_idle", 63 .owner = THIS_MODULE, 64 }; 65 66 void sh_mobile_setup_cpuidle(void) 67 { 68 struct cpuidle_device *dev = &cpuidle_dev; 69 struct cpuidle_driver *drv = &cpuidle_driver; 70 struct cpuidle_state *state; 71 int i; 72 73 74 for (i = 0; i < CPUIDLE_STATE_MAX; i++) { 75 drv->states[i].name[0] = '\0'; 76 drv->states[i].desc[0] = '\0'; 77 } 78 79 i = CPUIDLE_DRIVER_STATE_START; 80 81 state = &drv->states[i++]; 82 snprintf(state->name, CPUIDLE_NAME_LEN, "C1"); 83 strncpy(state->desc, "SuperH Sleep Mode", CPUIDLE_DESC_LEN); 84 state->exit_latency = 1; 85 state->target_residency = 1 * 2; 86 state->power_usage = 3; 87 state->flags = 0; 88 state->flags |= CPUIDLE_FLAG_TIME_VALID; 89 state->enter = cpuidle_sleep_enter; 90 91 drv->safe_state_index = i-1; 92 93 if (sh_mobile_sleep_supported & SUSP_SH_SF) { 94 state = &drv->states[i++]; 95 snprintf(state->name, CPUIDLE_NAME_LEN, "C2"); 96 strncpy(state->desc, "SuperH Sleep Mode [SF]", 97 CPUIDLE_DESC_LEN); 98 state->exit_latency = 100; 99 state->target_residency = 1 * 2; 100 state->power_usage = 1; 101 state->flags = 0; 102 state->flags |= CPUIDLE_FLAG_TIME_VALID; 103 state->enter = cpuidle_sleep_enter; 104 } 105 106 if (sh_mobile_sleep_supported & SUSP_SH_STANDBY) { 107 state = &drv->states[i++]; 108 snprintf(state->name, CPUIDLE_NAME_LEN, "C3"); 109 strncpy(state->desc, "SuperH Mobile Standby Mode [SF]", 110 CPUIDLE_DESC_LEN); 111 state->exit_latency = 2300; 112 state->target_residency = 1 * 2; 113 state->power_usage = 1; 114 state->flags = 0; 115 state->flags |= CPUIDLE_FLAG_TIME_VALID; 116 state->enter = cpuidle_sleep_enter; 117 } 118 119 drv->state_count = i; 120 dev->state_count = i; 121 122 cpuidle_register_driver(&cpuidle_driver); 123 124 cpuidle_register_device(dev); 125 } 126