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