1 /* linux/arch/arm/mach-exynos/cpuidle.c 2 * 3 * Copyright (c) 2011 Samsung Electronics Co., Ltd. 4 * http://www.samsung.com 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 11 #include <linux/cpuidle.h> 12 #include <linux/cpu_pm.h> 13 #include <linux/export.h> 14 #include <linux/module.h> 15 #include <linux/platform_device.h> 16 17 #include <asm/proc-fns.h> 18 #include <asm/suspend.h> 19 #include <asm/cpuidle.h> 20 21 static void (*exynos_enter_aftr)(void); 22 23 static int exynos_enter_lowpower(struct cpuidle_device *dev, 24 struct cpuidle_driver *drv, 25 int index) 26 { 27 int new_index = index; 28 29 /* AFTR can only be entered when cores other than CPU0 are offline */ 30 if (num_online_cpus() > 1 || dev->cpu != 0) 31 new_index = drv->safe_state_index; 32 33 if (new_index == 0) 34 return arm_cpuidle_simple_enter(dev, drv, new_index); 35 36 exynos_enter_aftr(); 37 38 return new_index; 39 } 40 41 static struct cpuidle_driver exynos_idle_driver = { 42 .name = "exynos_idle", 43 .owner = THIS_MODULE, 44 .states = { 45 [0] = ARM_CPUIDLE_WFI_STATE, 46 [1] = { 47 .enter = exynos_enter_lowpower, 48 .exit_latency = 300, 49 .target_residency = 100000, 50 .flags = CPUIDLE_FLAG_TIME_VALID, 51 .name = "C1", 52 .desc = "ARM power down", 53 }, 54 }, 55 .state_count = 2, 56 .safe_state_index = 0, 57 }; 58 59 static int exynos_cpuidle_probe(struct platform_device *pdev) 60 { 61 int ret; 62 63 exynos_enter_aftr = (void *)(pdev->dev.platform_data); 64 65 ret = cpuidle_register(&exynos_idle_driver, NULL); 66 if (ret) { 67 dev_err(&pdev->dev, "failed to register cpuidle driver\n"); 68 return ret; 69 } 70 71 return 0; 72 } 73 74 static struct platform_driver exynos_cpuidle_driver = { 75 .probe = exynos_cpuidle_probe, 76 .driver = { 77 .name = "exynos_cpuidle", 78 .owner = THIS_MODULE, 79 }, 80 }; 81 82 module_platform_driver(exynos_cpuidle_driver); 83