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 <asm/suspend.h> 18 #include <asm/uaccess.h> 19 #include <asm/hwblk.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 }; 25 26 static int cpuidle_sleep_enter(struct cpuidle_device *dev, 27 struct cpuidle_state *state) 28 { 29 unsigned long allowed_mode = arch_hwblk_sleep_mode(); 30 ktime_t before, after; 31 int requested_state = state - &dev->states[0]; 32 int allowed_state; 33 int k; 34 35 /* convert allowed mode to allowed state */ 36 for (k = ARRAY_SIZE(cpuidle_mode) - 1; k > 0; k--) 37 if (cpuidle_mode[k] == allowed_mode) 38 break; 39 40 allowed_state = k; 41 42 /* take the following into account for sleep mode selection: 43 * - allowed_state: best mode allowed by hardware (clock deps) 44 * - requested_state: best mode allowed by software (latencies) 45 */ 46 k = min_t(int, allowed_state, requested_state); 47 48 dev->last_state = &dev->states[k]; 49 before = ktime_get(); 50 sh_mobile_call_standby(cpuidle_mode[k]); 51 after = ktime_get(); 52 return ktime_to_ns(ktime_sub(after, before)) >> 10; 53 } 54 55 static struct cpuidle_device cpuidle_dev; 56 static struct cpuidle_driver cpuidle_driver = { 57 .name = "sh_idle", 58 .owner = THIS_MODULE, 59 }; 60 61 void sh_mobile_setup_cpuidle(void) 62 { 63 struct cpuidle_device *dev = &cpuidle_dev; 64 struct cpuidle_state *state; 65 int i; 66 67 cpuidle_register_driver(&cpuidle_driver); 68 69 for (i = 0; i < CPUIDLE_STATE_MAX; i++) { 70 dev->states[i].name[0] = '\0'; 71 dev->states[i].desc[0] = '\0'; 72 } 73 74 i = CPUIDLE_DRIVER_STATE_START; 75 76 state = &dev->states[i++]; 77 snprintf(state->name, CPUIDLE_NAME_LEN, "C0"); 78 strncpy(state->desc, "SuperH Sleep Mode", CPUIDLE_DESC_LEN); 79 state->exit_latency = 1; 80 state->target_residency = 1 * 2; 81 state->power_usage = 3; 82 state->flags = 0; 83 state->flags |= CPUIDLE_FLAG_SHALLOW; 84 state->flags |= CPUIDLE_FLAG_TIME_VALID; 85 state->enter = cpuidle_sleep_enter; 86 87 dev->safe_state = state; 88 89 state = &dev->states[i++]; 90 snprintf(state->name, CPUIDLE_NAME_LEN, "C1"); 91 strncpy(state->desc, "SuperH Sleep Mode [SF]", CPUIDLE_DESC_LEN); 92 state->exit_latency = 100; 93 state->target_residency = 1 * 2; 94 state->power_usage = 1; 95 state->flags = 0; 96 state->flags |= CPUIDLE_FLAG_TIME_VALID; 97 state->enter = cpuidle_sleep_enter; 98 99 dev->state_count = i; 100 101 cpuidle_register_device(dev); 102 } 103